Research ArticleExperimental Investigation of the Phase Equilibria inthe Al-Mn-Zn System at 400∘C

Tian Wang Dmytro Kevorkov Ahmad Mostafa and Mamoun Medraj

Department of Mechanical Engineering Concordia University 1455 de Maisonneuve Boulevard WestMontreal QC Canada H3G 1M8

Correspondence should be addressed to Mamoun Medraj mmedrajencsconcordiaca

Received 5 April 2014 Accepted 16 June 2014 Published 17 July 2014

Academic Editor Alok Singh

Copyright copy 2014 Tian Wang et al This is an open access article distributed under the Creative Commons Attribution Licensewhich permits unrestricted use distribution and reproduction in any medium provided the original work is properly cited

Al-Mn-Zn ternary system is experimentally investigated at 400∘C using diffusion couples and key alloys Phase relationships andhomogeneity ranges are determined for binary and ternary compounds using EPMA SEMEDS and XRD Reported ternarycompound T3 (Al

11

Mn3

Zn2

) is confirmed in this study and is denoted as 1205912

in this paper Two new ternary compounds (1205911

and1205913

) are observed in this system at 400∘C 1205911

is determined as a stoichiometric compound with the composition of Al31

Mn8

Zn11

1205913

has been found to have homogeneity range of Al119909

Mn119910

Zn119911

(119909 = 9ndash13 at 119910 = 11ndash15 at 119911 = 75ndash77 at) The binary compoundsAl4

Mn and Al11

Mn4

exhibit limited solid solubility of around 6 at and 4 at Zn respectively Terminal solid solution Al8

Mn5

is found to have maximum ternary solubility of about 10 at Zn In addition ternary solubility of Al-rich 120573-Mn1015840 at 400∘C isdetermined as 4 at Zn Zn-rich 120573-Mn10158401015840 has a ternary solubility of 3 at Al The solubility of Al in Mn

5

Zn21

is measured as 5 atBased on the current experimental results the isothermal section of Al-Mn-Zn ternary system at 400∘C has been constructed

1 Introduction

Automotive industry represents one of the most importantmarkets for aluminum alloys The use of aluminum and itsalloys offers considerable potential to reduce the weight ofan automobile body or engine without compromising per-formance and safety [1] Many different elements includingMg Cu Zn Mn Si and so forth are used to improve theproperties of Al alloy for specific applications Al-Zn basedalloys have high strength and hardness improved creepwear resistance and low density It is well known that asmall amount of Mn added to Al alloys plays a positiverole in improving the fracture toughness recrystallizationgrain refinement and resistance to stress corrosion fatigueof these alloys [1ndash3] Because the Al-Mn-Zn system is animportant ternary system for the development of Al alloysit is essential to understand the phase relationships in thesystem In addition this system is an essential subsystem forAZ AM-series magnesium alloys high strength steels andfor galvanizing-related alloy systems [4 5]

The three constituent binary systems were reasonablystudied Khan and Medraj [6] reevaluated the Al-Mn system

which was in good agreement with most of the experimentalresults [7ndash10] From their work [6] thermodynamic calcula-tion almost reproduced the EPMA results of Minamino et al[11] Their calculation was consistent with the observation ofOkamoto [12] who suggested a smooth continuous liquiduscurve between the terminal 120575-phase (BCC) throughout the120576-phase (HCP) as mentioned by Taylor [13] Al-Zn systemwas critically reviewed by Wasiur-Rahman and Medraj [14]lately Their description showed good agreement with mostof the experimental results Mn-Zn system was reviewed byOkamoto and Tanner [15] They proposed that there couldbe three possible separated phase fields (120576 120576

1 and 120576

2) in

the epsilon phase region They [15] suggested that 1205761and

1205762phases can possibly be metastable phases based on the

analysis of [16ndash19] However the presence of these separatedphase regions has not been validated in the published lit-erature Recently Liang et al [20ndash22] analyzed 120576-phase at400∘C 500∘C and 600∘C Based on their observations thesubdivision of the 120576-phase region could not be confirmed

Up to date little effort has been made to describe thephase relationships in the Al-Mn-Zn ternary system Thepartial Al-Mn-Zn liquidus projection near theZn-rich corner

Hindawi Publishing CorporationJournal of MaterialsVolume 2014 Article ID 451587 13 pageshttpdxdoiorg1011552014451587

2 Journal of Materials

was studied by Gebhardt [23] Later Raynor and Wakeman[24] synthesized three ternary compounds (T1 Al

24Mn5Zn

T2 Al9Mn2Zn and T3 Al

11Mn3Zn2) using electrolytic

deposition and not by alloying They [24] pointed out thatAl4Mn dissolves up to 52 wt Zn whereas Al

6Mn dissolves

only 078wt Zn These two compounds were characterizedbased on the substitution of Mn by Zn atoms Subsequentlyseveral researchers [25ndash28] focused on the crystal structuralanalysis of the ternary compounds reported by Raynor andWakeman [24] Robinson [25] found that T1 was C-centeredorthorhombic phase with 119886 = 248 119887 = 251 and 119888 =303 nm lattice parameters The structure of T3 was found byDamjanovic [26] which also has C-centered orthorhombicunit cell with 119886 = 778 119887 = 238 and 119888 = 126 nm latticeparameters Schaefer et al [27] showed that addition of Znto Al-Mn alloys promoted the formation of decagonal phaseSingh et al [28] used TEM to examine the formation andthe approximant structures of Al

24Mn5Zn and Al

12Mn29Zn

(close to T3 phase) quasicrystals in melt-spun conditionThey [28] observed that melt spinning could lead to theformation of icosahedral phase in Al

24Mn5Zn and decagonal

phase in Al12Mn29Zn Up to now the experimental phase

equilibrium information and thermodynamic data are insuf-ficient for the accurate description of this system Thereforeexperimental investigations of the phase equilibrium in theAl-Mn-Zn ternary system are specifically performed in thepresent work to provide the phase relationships in this systemat 400∘C

2 Experimental Procedures

Diffusion couple technique is a powerful and efficient tool forphase diagram determination [29ndash31] The layer formationin diffusion couples represents the local equilibria at theinterfaces Ternary diffusion couples may contain two phasesin one layer because of the additional degree of freedom[31] Thus three-phase equilibria can be determined atthe interfaces of such layers However ternary diffusioncouples have unpredictable diffusion paths that can lead toomitting some phases Moreover slow kinetic formation ofsome phases may cause the formation of extremely thinlayers that might be difficult to be successfully analyzedTherefore key alloys are used to verify the phase relationshipsobtained from diffusion couple experiments In this workthe experimental procedure was based on the combinationof diffusion couple and key alloys techniques The startingmaterials for both diffusion couples and key alloys were Alingots with purity 997 Zn rods with purity 9999 andMn pieces with purity 99 All of which were suppliedby Alfa Aesar A Johnson Matthey Company Alloys wereprepared in an induction-melting furnace with a Ta crucibleunder an argon protective atmosphere All samples wereremelted three times to assure homogeneityThe actual globalcomposition of the prepared samples was determined byinductively coupled plasmaoptical emission spectrometry(ICPOES) The specimens for ICP analysis were taken from3 different locations of the sample to assure the accuracy ofthe analysis

Table 1 Terminal compositions of diffusion couples along withannealing time

Diffusion couple number End-members Annealing timeDC1 Al-Mn

11

Zn89

30 daysDC2 Mn-Al

94

Zn6

15 and 25 daysDC3 Al-Mn

13

Zn87

30 daysDC4 Mn-Al

65

Mn30

Zn5

30 daysDC5 Al-Mn

32

Zn68

30 days

00 02 04 06 08 10

00

02

04

06

08

10 00

02

04

06

08

10

Mole fraction M

n

Al Zn

Mn

Mole

frac

tion

Al

Mole fraction ZnAl-f

cc

Liqu

idZn

-HCP

Diffusion couplesActual compositions of key samples

Al8Mn5

Al6MnAl4Mn

120573-Mn998400 120573-Mn998400998400

Al11Mn4

Al12MnMnZn13

MnZn9Mn5Zn21

120572-Mn

120576

Figure 1 Terminal compositions of diffusion couples and actualcompositions of key alloys

Preliminary study was carried out using three diffusioncouples DC 1 to 3 Diffusion couples were prepared by grind-ing down the contacting interfaces using 1200 grit SiC paperand then polished up to 1 120583m using alcohol-based diamondsuspension 99 pure ethanol was used as lubricant Theselected end-members were carefully pressed and clampedtogether using a stainless steel ring placed in a Ta containerand sealed in a quartz tube under vacuum atmosphere Theencapsulated samples were then annealed at 400∘C for 4weeks After obtaining preliminary results from the first threediffusion couples two more diffusion couples (DC 4 and 5)and seventeen key alloys (1 to 17) were prepared to obtainthe main phase relationships The composition of the end-members used in diffusion couples are listed in Table 1 Theselection of these end-members was based on preliminarythermodynamic calculations using the models of the binarysystems reported by [6 14 32] The probable diffusion pathswere expected to cross several phase regions which couldlead to formation of large number of the diffusion layersThe compositions of the selected key alloys and the terminalcomposition of the diffusion couples are plotted in Figure 1

Journal of Materials 3

In order to identify the minor inconsistencies the final studywas preceded by preparing another nine key samples (18 to26) All the key alloys were annealed at 400∘C for 4 weeks

The selection of annealing temperature is based on thehomogenization time of alloys and theirmelting temperatureThe annealing temperature should be high enough for fasthomogenization interdiffusion and kinetics in the alloysMeanwhile the annealing temperature should be lower thanthe melting temperature of the alloys The lowest eutectictemperature in this system is around 390∘C in Zn-richcorner However this work is focused on Al-alloys and allsamples were prepared away from Zn-rich corner Therefore400∘C was selected in order to have faster interdiffusion andrelatively shorter annealing time

Key alloys and diffusion couples were investigated usingelectron probe microanalysis (EPMA) and scanning elec-tron microscopy (SEM) equipped with energy dispersiveX-ray spectroscopy (EDS) The microstructure and phasecomposition of the samples were analyzed either by EPMA(JOEL-JXA-8900) or SEMEDS (HITACHI S-3400N) Thedifference between EPMA and SEMEDS results was lessthan 2 at for Mn This value was obtained by comparingthe composition of several samples using both techniquesX-ray diffraction (XRD) was used for phase analysis of thekey alloys and for the determination of the solubility limitsof the compounds The XRD patterns were obtained usingPANanalytical Xpert Pro powder X-ray diffractometer [33]with a CuK120572 radiation at 45 kV and 40mA X-ray diffractionanalysis of the samples was carried out using XrsquoPert High-Score Plus Rietveld analysis software [33] Pearsonrsquos crystaldatabase [34] was used to identify the known phases in theAl-Mn-Zn system

3 Results and Discussion

31 Experimental Study of Diffusion Couples Isothermalsection of the Al-Mn-Zn ternary system was constructedbased on the experimental results of 5 diffusion couplesand 26 key samples shown in Figure 1 During the prelimi-nary study three ternary compounds 120591

1(Al31Mn8Zn11) 1205912

(Al71Mn16Zn13) and 120591

3(Al10Mn15Zn75) have been found

through diffusion couples analysisBackscattered electron image of DC 1 (Al-Mn

11Zn89) is

presented in Figure 2(a) Half of the image is colored forbetter representation of diffusion layers in this diffusion cou-ple The interdiffusion took place which led to the formationof several diffusion layers The compositions of the formedphases were determined using EPMA point analysis EPMAline-scan was used to determine the solubility ranges andphase equilibria among intermetallics Based on the compo-sition profile obtained by EPMA as shown in Figure 2(b)the diffusion path was depicted based on the sequence ofthe phases as Mn

5Zn21rarr Al

8Mn5rarr Al

11Mn4rarr

1205911rarr Al-fcc New ternary intermetallic compound 120591

1has

been found in this diffusion couple 1205911was determined as a

compound with the composition of Al62Mn16Zn22 As can

be seen from Figure 2(b) the three points of EPMA resultsshow no solubility range of 120591

1 Additional key alloy analysis

was consistent with the results of DC 1 (Al-Mn11Zn89)

This is why this compound is considered as stoichiometricFigure 2(c) shows the estimated diffusion path of DC 1 (Al-Mn11Zn89) plotted on the Al-Mn-Zn Gibbs triangle Layer

number 1 was determined asMn5Zn21 The solubility of Al in

Mn5Zn21

was measured as 5 at where Al atoms substituteZn atoms and Mn content remains constant at 16 at Basedon the local equilibrium at the Mn

5Zn21Al8Mn5interface

Mn5Zn21

is in equilibrium with Al8Mn5 In layer number

2 Al8Mn5solid solution dissolves up to 7 at Zn as shown

in Figure 2(b) This homogeneity range was also confirmedby DC 4 (Mn-Al

65Mn30Zn5) DC 5 (Al-Mn

32Zn68) and key

alloys 13ndash17The composition of Al8Mn5did not vary in DC 1

(Al-Mn11Zn89) because the diffusion path changed direction

to form Al11Mn4layer Layer number 3 was determined as

Al11Mn4with limited ternary solubility of around 2 at Zn

This value can be considered negligible because the estimatederror of EPMAmeasurement is about 2 at Layer number 4contains two phases these are Al

11Mn4and 1205911 The results of

point analysis indicated that Al11Mn4has negligible ternary

solubility and 1205911has the composition of Al

62Mn16Zn22 Layer

number 5 was identified as 1205911 Results of line-scan across

1205911layer showed that the composition of 120591

1is constant as

Al62Mn16Zn22 In layer number 6 Al-fcc was in equilibrium

with 1205911 The solubility of Zn in Al-fcc was found to reach up

to 20 at based on the EPMA line-scan resultsDC 2 (Mn-Al

94Zn6) was annealed at 400∘C for two

different time periods (15 and 25 days) in order to understandthe phase formation kinetics The annealing time resultedin significant growth of some compounds at the expense ofothersThis can be clearly seen in Figures 3(a) and 3(b) wherethe layer thickness of Al

11Mn4is growing at the expense of

Al4Mn and 120591

2 Six layers were observed in this diffusion cou-

ple for both annealing times The sequence of the observedphases is represented as follows Al-fcc rarr 120591

2rarr Al

4Mn rarr

Al11Mn4rarr Al

8Mn5rarr 120573-Mn1015840 rarr 120573-Mn10158401015840 rarr Mn The

ternary compound T3 (Al11Mn3Zn2) reported by [24] was

observed in this diffusion couple and is denoted as 1205912in this

paper as shown in Figures 3(a) and 3(b) 1205912was determined

as Al71Mn16Zn13 which is close to the composition of T3

(Al69Mn19Zn12) as reported byRaynor andWakeman [24] In

DC 2 (Mn-Al94Zn6) finger-like structuremorphology can be

observed after annealing for 15 days as shown in Figure 3(b)This type of morphology indicates anisotropic diffusion ofthe three elements in this system Al

11Mn4showed higher

growth rate compared to other phases in this diffusion coupleThis was concluded by comparing the micrographs of DC 2(Figures 3(a) and 3(b)) Both thicknesses of 120591

2and Al

4Mn

decreased after annealing for additional 10 days as shown inFigure 3(b) The Mn content of Al

4Mn was found to vary

from 18 at to 20 at after annealing for 15 days whereas itbecame constant at 20 atMnafter annealing for 25 daysThesolubility of Zn in Al

4Mn was measured as 5 at SEMEDS

analysis of DC 2 (Mn-Al94Zn6) annealed for 25 days is

presented in Figure 3(c) The solubility of Zn in Al8Mn5was

measured as 5 at The ternary solid solubility of 120573-Mn1015840 wasfound to be 4 at Zn 120573-Mn10158401015840 shows limited ternary solubilityof 3 at Al

4 Journal of Materials

Al-fcc

Line-scan

1 2 3 4 5 6

Al8Mn5 Al11Mn4 1205911Mn5Zn21 Al11Mn4 + 1205911

15120583m

(a)

0 2 4 6 8 10 12 14 16 18 20 22 240

102030405060708090

100

Al-fcc

Elem

ents

(at

)

Points number

ZnMnAl

Al8Mn5 Al11Mn4 1205911Mn5Zn21

(b)

4

6

5

3

2

Composition of detected phases

Mole fraction M

nMole

frac

tion

Al

Zn0 20 40 60 80 100

0

20

40

60

80

100 0

20

40

60

80

100

Mn

Al

Mole fraction Zn

DC 1

Diffusion path

1

6 Al-fcc layer

Al8Mn5

Al6MnAl4Mn

120573-Mn998400 120573-Mn998400998400

Al11Mn4

Al12MnMnZn13

MnZn9Mn5Zn21

120576

400∘C

1 Mn5Zn21 layer2 Al8Mn5 layer3 Al11Mn4 layer

4 Al11Mn4 + 1205911 layer5 1205911 layer

Al-f

cc

Liqu

idZn

-HCP

(c)

Figure 2 (a) Backscattered electron image of DC 1 (Al-Mn11

Zn89

) and its schematic (b) composition profile of the line-scan in DC 1 (Al-Mn11

Zn89

) (c) approximation of diffusion path of DC 1 (Al-Mn11

Zn89

)

Journal of Materials 5

Al8Mn5

Al4MnMn 120573-Mn998400

120573-Mn998400998400

Al11Mn4

Al-fcc1205912

(a)

Al8Mn5

Al4MnMn

120573-Mn998400

120573-Mn998400998400

Al11Mn4

Al-fcc

1205912

(b)

0 20 40 60 80 100

0

20

40

60

80

100 0

20

40

60

80

100

Composition of detected phases

Mole fraction M

nMole

frac

tion

Al

Zn

Mn

Al

Diffusion path

DC2

25 days

Mole fraction Zn

400∘C

Al8Mn5

Al6MnAl4Mn

120573-Mn998400 120573-Mn998400998400

Al12MnMnZn13

MnZn9Mn5Zn21

120576

1205912

Al11Mn4

Al-f

cc

Liqu

idZn

-HCP

(c)

Mole

frac

tion

Al

0 20 40 60 80 100

0

20

40

60

80

100 0

20

40

60

80

100

15 days25 days

Mole fraction M

n

Zn

Mn

Al

Mole fraction Zn

400∘C

Al8Mn5

Al6MnAl4Mn

120573-Mn998400 120573-Mn998400998400

Al11Mn4

Al12MnMnZn13

MnZn9Mn5Zn21

120576

1205912

Al-f

cc

Liqu

idZn

-HCP

(d)

Figure 3 (a) Backscattered electron image of DC 2 (Mn-Al94

Zn6

) annealed at 400∘C for 15 days along with its schematic (b) backscatteredelectron image of DC 2 (Mn-Al

94

Zn6

) annealed at 400∘C for 25 days along with its schematic (c) diffusion path of DC 2 (Mn-Al94

Zn6

)annealed for 25 days (d) comparisons of DC 2 (Mn-Al

94

Zn6

) annealed at 15 days and 25 days

Al-fcc

Al4Mn

50120583m

1205911

Figure 4 Backscattered electron image of sample 1

DC 3 (Al-Mn13Zn87) was studied using the same

approach as for DC 1 (Al-Mn11Zn89) and DC 2 (Mn-

Al94Zn6) Four phases have been identified through EPMA

analysis 1205913 Al8Mn5 Al11Mn4 and Al-fcc EPMA point

analysis indicated that the 1205913ternary compound had the

composition of Al10Mn15Zn75 Other than this the results of

this diffusion couple only confirmed the data obtained fromDC 1 and 2Therefore the details of DC 3 (Al-Mn

13Zn87) are

not mentioned here to avoid repetition

32 Experimental Study of Key Alloys Ten key alloys wereprepared to verify the formation of phases reported in theliterature and confirm the presence of the ternary compounds1205911 1205912 and 120591

3found in this experimental study The actual

6 Journal of Materials

Al-fcc

Al4Mn

Al6Mn

20120583m

(a)

Al-fcc

Al4Mn

Al6Mn

(b)

Figure 5 (a) Backscattered electron image of as-cast sample 7 (b) backscattered electron image of annealed sample 7

30 35 40 45 50 55 60 65 70 75 80 850

50

100

150

200

250

Al 148

Cou

nts

Position of 2120579

Al4Mn 562

Al6Mn 29

(a)

30 35 40 45 50 55 60 65 70 75 80 850

100

200

300

400

500

Cou

nts

Al 108

Position of 2120579

Al4Mn 14

Al6Mn 752

(b)

Figure 6 (a) XRD spectrum of as-cast sample 7 (b) XRD spectrum of annealed sample 7

Al4Mn Al-fcc

1205912

Figure 7 Backscattered electron image of sample 3

composition of these key alloys and the composition of thedetected phases are presented in Table 2

The ternary compounds T1 (Al24Mn5Zn) and T2

(Al9Mn2Zn) [24] were not observed in this system at 400∘C

As shown in Table 2 key alloy 7 was prepared close tothe composition of T1 compound key alloys 5 and 6 weremade close to the composition of T2 compound HoweverT1 and T2 were not detected It should be mentioned thatRaynor and Wakeman [24] used only as-cast samples intheir study and reported compounds could be metastable orhigh temperature phases Furthermore they [24] have usedthe wet chemical analysis of small quantities of extractedcrystals which may cause errors in phase compositionsdetermination compared to EPMA point analysis usedin our work The existence of 120591

1phase was confirmed in

sample 1 as a stoichiometric compound with Al64Mn15Zn21

composition The microstructure of this alloy is shown inFigure 4 120591

1formed during a peritectic reaction which is hard

to be terminated during short annealing period Thereforethe primary phase Al

4Mn was not decomposed completely

even after annealing for 30 days Similar phenomenon wasalso observed in key sample 7 Figures 5(a) and 5(b) showthe as-cast and annealed microstructures of sample 7 It isclear that Al

4Mn (the white phase) formed as a primary

phase Al6Mn then formed according to the peritectic

reaction L + Al4Mn rarr Al

6Mn After annealing for 30 days

Journal of Materials 7

Table 2 The actual compositions of the key samples and the detected phases

Samplenumber

Actual compositionidentified by ICP (at) Phase identification

Composition ofidentified phasesby EPMA (at)

Al Mn Zn ByEPMA

ByXRD Al Mn Zn

1 44 16 40Al4Mn Al4Mn 74 20 61205911

64 15 21Al-fcc Al-fcc 55 0 45

2 75 13 121205912

1205912

73 15 12Al4Mn Al4Mn 74 20 6Al-fcc Al-fcc 78 0 22

3 78 15 71205912

1205912

75 14 11Al4Mn Al4Mn 75 20 5Al-fcc Al-fcc 88 0 12

4 79 10 111205912

1205912

72 16 12Al4Mn Al4Mn 76 20 4Al-fcc Al-fcc 79 0 21

5 74 16 101205912

1205912

73 15 12Al4Mn Al4Mn 74 20 6Al-fcc Al-fcc 75 0 25

6 74 15 111205912

1205912

72 15 13Al4Mn Al4Mn 74 20 6Al-fcc Al-fcc 80 0 20

7 84 12 4Al6Mn Al6Mn 86 14 0Al4Mn Al4Mn 75 20 5Al-fcc Al-fcc 95 0 5

8 82 11 7Al12Mn 92 8 0Al6Mn 83 15 2Al-fcc 96 0 4

9 21 14 651205913

12 11 77Al11Mn4 Al11Mn4 70 26 3Al8Mn5 Al8Mn5 56 37 7

10 16 14 701205913

12 11 771205914

23 16 61Al11Mn4 Al11Mn4 71 25 4

11 23 16 61

1205913

13 13 741205914

25 18 57Al11Mn4 Al11Mn4 69 27 4Al8Mn5 Al8Mn5 55 36 9

12 17 15 68Al11Mn4 Al11Mn4 70 26 41205913

13 11 761205914

23 16 61

13 18 22 60 1205913

10 15 75Al8Mn5 Al8Mn5 52ndash57 33ndash37 10ndash11

14 64 31 5 Al11Mn4 Al11Mn4 70 26 4Al8Mn5 Al8Mn5 55 34 10

15 56 37 7 Al8Mn5 Al8Mn5 57 39 4

16 55 35 10 Al11Mn4 Al11Mn4 70 27 3Al8Mn5 Al8Mn5 57 34 9

17 30 35 35 Al8Mn5 54 38 8120576 74 22 4

8 Journal of Materials

(a)

Al8Mn5

Al11Mn4

1205913

(b)

Al11Mn4

1205913

1205914

10120583m

(c)

Al11Mn4

1205913

100120583m

(d)

Figure 8 (a) Backscattered electron image of annealed sample 9 at 400∘C for 30 days (b) magnified area of sample 9 (c) backscatteredelectron image of sample 10 annealed at 400∘C for 25 days (d) backscattered electron image of sample 10 annealed at 400∘C for 40 days

30 35 40 45 50 55 60 65 70 75 800

50100150200250300350400450500550600650700

Al

Cou

nts

Position of 2120579

Al4Mn1205911

Figure 9 XRD spectrum of annealed sample 1

the amount of Al4Mn decreased and decomposed to Al

6Mn

The microstructure of annealed sample 7 is shown inFigure 5(b) Using XRD analysis the weight fraction ofAl4Mn and Al

6Mn in the as-cast sample was measured

as 562 and 29 respectively as shown in Figure 6(a)

The amount of Al4Mn and Al

6Mn changed dramatically

after annealing for 30 days to become 14 and 822as demonstrated in Figure 6(b) This variation indicatesperitectic decomposition upon annealing Due to the naturalsluggish kinetics of peritectic reaction the transformation ofAl4Mn to Al

6Mn requires very long time

The formation of 1205912was confirmed after analysis of key

alloys 2 to 6 The microstructure of sample 3 is shown inFigure 7 EPMA results indicated that 120591

2is a stoichiometric

compound with Al71Mn16Zn13

composition It has beenobserved that the Mn content of Al

4Mn varies in the range of

18ndash21 at which could be owing to the Zn substitution Thedissolved Zn in Al

4Mn was found to reach up to 6 at Sub-

stitution of third element could lead to the small variationsof compositions On the other hand these Mn content devia-tions could be due to the fact that Al

4Mn forms quasicrystals

The structure of quasicrystal may change under differentsolidification conditions [27] Schaefer et al [27] mentionedthat Al

4Mn formed icosahedral or decagonal quasicrystals

and structural changes in solid solutions could affect the com-positions They [27] observed that composition of ternaryquasicrystals most likely fall in the range of 18ndash22 at Mnwhich was close to the composition region of the stable 120583-Al4Mn phase The composition of reported T1 is close to

Journal of Materials 9

30 35 40 45 50 55 60 65 70 75 800

50

100

150

200

250

300

350C

ount

s

Position of 2120579

(a)

30 35 40 45 50 55 60 65 70 75 800

50

100

150

200

250

300

350

Cou

nts

Position of 2120579

(b)

30 35 40 45 50 55 60 65 70 75 800

50

100

150

200

250

300

Cou

nts

SiAl

Position of 2120579

Al4Mn1205912

(c)

Figure 10 (a) XRD spectrum of annealed sample 2 (b) XRD spectrum of annealed sample 3 (c) XRD spectrum of annealed sample 5

the homogeneity range of Al4Mn which indicated that T1

might be a quasicrystal of Al4Mnwith extended Zn solubility

1205913was observed in DC 3 (Al-Mn

13Zn87) and the com-

position was primarily determined as Al10Mn15Zn75 Several

key alloys were prepared to study this new compound Theactual compositions of these samples and the compositionsof the detected phases are listed in Table 2 The 120591

3phase has

a complex homogeneity range 9ndash13 at Al 11ndash15 at Mnand 75ndash77 at Zn as was determined by the analysis of DC3 (Al-Mn

13Zn87) and key samples 9 to 13 Sample 9 is an

example of these findings as shown in Figures 8(a) and 8(b)The sample contains residuals of the primary Al

8Mn5phase

that decomposes according to the peritectic reaction L+Al8Mn5rarr Al

11Mn4 The decomposition of Al

8Mn5was not

complete due to the slow kinetics of the peritectic reaction 1205913

phase formed a matrix in this alloyThe homogeneity ranges of the binary compounds were

determined using EPMA From the EPMA results Al11Mn4

exhibited ternary solubility reaching up to 4 at Zn Al4Mn

had the maximum ternary solubility of 6 at Zn Thedissolved Zn in Al-fcc was found to reach up to 45 atTernary homogeneity range of Al

8Mn5has been determined

by EPMA as 11 atZnThese observations also confirmed theresults which were inferred from DC 4 (Mn-Al

65Mn30Zn5)

Additionally another ternary phase 1205914was found in this

ternary system The composition of this phase is in the

region around Al23Mn16Zn61 However 120591

4is found to be

metastable As shown in Figure 8(c) three phases Al11Mn4

1205913 and 120591

4were found in sample 12 to be annealed at 400∘C

for 25 days After prolonged annealing for another 15 days 1205914

decomposed to provide more 1205913and Al

11Mn4

In order to verify the observations of the ternary com-pounds key alloys were studied using XRD The XRDpatterns of sample 1 are illustrated in Figure 9 Al-fcc andAl4Mn are positively identified in the XRD pattern Besides

there are several peaks which do not belong to any of theknown binary phases in the system Based on the resultsof phase identifications those peaks could correspond to1205911 Because of the lack of the reported prototype of 120591

1 the

peaks which belong to 1205911were hard to separate due to the

several overlapping peaks in the XRD pattern of this sampleThus the crystal structure of this compound could not bedetermined in the current study However the peaks whichcould belong to 120591

1have been labeled as shown in Figure 9

T3 phase reported by [24] denoted as 1205912in the current

study was confirmed through XRD analysis Three XRDspectra of sample 2 3 and 5 were used for this purpose Asshown in Figure 10 the XRD patterns of the three samplesare similar From 2120579 position 40∘ to 45∘ hump-like patternscan be observed due to peaks overlapping This is becauseAl4Mnhas very complex crystal structure and has around 550

atoms in a giant unit cell [34] During the X-ray scanning

10 Journal of Materials

Mn

Al8Mn5Al8Mn5

120573-Mn998400

Al11Mn4

50120583m

(a)

0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 340

10

20

30

40

50

60

70

80

90

100

Elem

ents

(at

)

Points number

MnZn

AlAl8Mn5

Al8Mn5120573-Mn998400

Al11Mn4

Al8Mn5

Al11Mn4

(b)

Figure 11 (a) Backscattered electron image of diffusion couple DC 4 (Mn-Al65

Mn30

Zn5

) (b) composition profile of line-scan in diffusioncouple DC 4 (Mn-Al

65

Mn30

Zn5

)

process the diffracted spectra of Al4Mn were overlapping

with other peaks at numerous positions and generate theseoverlapped patterns Using the crystallographic entry of T3from Pearsonrsquos database [34] T3 was positively identifiedamong XRD analysis Along with Al-fcc and Al

4Mn the

triangulation among those three phases was establishedXRD analysis of ternary compound 120591

3has similar issues

to 1205911as elucidated above Unfortunately too many peaks

were overlapping in a multiphase alloy and a single-phasesample representing 120591

3was not possible to prepareTherefore

the crystal structure of this compound has not been deter-mined either

33 Description of Ternary Solid Solutions

331 Homogeneity Range of Al8Mn5and Al

11Mn4 Al8Mn5

has wide homogeneity range in Al-Mn binary system How-ever it is difficult to estimate how much of Zn dissolvedin this compound from the results of DC 2 (Mn-Al

94Zn6)

Journal of Materials 11

Al8Mn5

Al11Mn4

80120583m

(a)

Al8Mn5

50120583m

(b)

20 25 30 35 40 45 50 550

100

200

300

400

500

600

Cou

nts

Position of 2120579

Al8Mn5

98 Al8Mn5

(c)

Figure 12 (a) Backscattered electron image of sample 14 (b) backscattered electron image of sample 15 (c) XRD spectrum of sample 15

Thus DC 4 (Mn-Al65Mn30Zn5) was prepared in order to

determine the homogeneity range of Al8Mn5in this ternary

system Because Al11Mn4has higher growth rate one end

member of DC 4 (Mn-Al65Mn30Zn5) has been selected near

the Al8Mn5region to increase the atomic exchange between

Al and Mn From the backscattered electron image of DC4 (Mn-Al

65Mn30Zn5) shown in Figure 11(a) Al

8Mn5formed

a thick layer and the color changed along with decreasingMn content which suggests the presence of a homogeneityrange Line-scan shown in Figure 11(b) was carried outto determine the homogeneity range of Al

8Mn5 In the

Al11Mn4+ Al8Mn5two-phase region dotted lines denote

the concentrations of elements in Al11Mn4and solid lines

represent the concentrations of elements in Al8Mn5 The

SEMEDS analysis showed that Al8Mn5has ternary solubility

of 9 at Zn and Al11Mn4has maximum ternary solubility

of 4 at Zn Al concentration in Al8Mn5layer varied from

49 at to 58 atAl11Mn4and Al

8Mn5showed extended ternary solubility

in this system at 400∘C In order to confirm the resultsobtained from previous diffusion couples four key alloys(14 to 17) were prepared The composition and phase iden-tification of these key samples are summarized in Table 2The phase relations obtained from EPMA showed greatconsistency with the XRD results Backscattered electronimage of sample 14 is shown in Figure 12(a) From EPMA

point analysis Al11Mn4has a ternary solubility of about 4 at

Zn and Al8Mn5has a maximum ternary solubility of 10 at

Zn These results were consistent with the previous EPMAobservation of samples 9 and 11 Figure 12(b) shows thatsample 15 contains mainly Al

8Mn5whose ternary solubility

was measured around 4 at Zn The XRD analysis also con-firmed that Al

8Mn5is dominating in sample 15 as shown in

Figure 12(c)There are a few unlabeled small peaks indicatingthe presence of Al

11Mn4traces which could not be identified

in the current study because of their low intensity

332 Single Region of 120576 Phase Controversy on whether120576 has three-phase separations reported in the assessmentof Okamoto and Tanner [15] is still not resolved In thecurrent study one end-member of DC 5 (Al-Mn

32Zn68)

has a composition in the 120576-phase region EPMA line-scanindicated that 120576-phase has continuous binary solubility rangesreaching fromMn

32Zn68to Mn

40Zn60at 400∘CThis finding

also corresponds to the Mn-Zn binary system which wasreported by [32 35] The backscattered electron image of DC5 (Al-Mn

32Zn68) is presented in Figure 13 Five phases have

been identified 120576 Al-rich 120573-Mn1015840 Al8Mn5 Al11Mn4 and Al-

fcc In the current experimental investigation the maximumsolubility of Zn in 120573-Mn1015840 was measured as 4 at Single 120576-phase region with the Mn content from 32 to 40 at was

12 Journal of Materials

Al8Mn5

120573-Mn998400

Al11Mn4

Al-fcc

Mn32Zn68(120576)

Figure 13 Backscattered electron image of DC 5 (Al-Mn32

Zn68

)

observed at 400∘C and nothing indicated the presence ofphase separation in this composition range From the resultsof sample 17 (Al

30Mn35Zn35) 120576-phase was found to have

limited ternary solubility of 4 at Al

34 Isothermal Section of Al-Mn-Zn System at 400∘C Com-bining the results which were obtained from the diffusioncouples with those obtained from the key alloys the Al-Mn-Zn isothermal section at 400∘C was constructed and pre-sented in Figure 14 Solid lines represent the experimentallyverified phase boundaries and ternary solubility of binaryphases Dotted lines are the estimated phase relationshipswhich were not confirmed in the current study They wereconstructed based on the Gibbs phase rule [36] and Schreine-makerrsquos rule [37] Grey blue and green areas indicate thesingle two-phase and three-phase regions separately asshown in Figure 14

4 Conclusion

The Al-Mn-Zn isothermal section at 400∘C was constructedbased on the current experimental results of diffusion coupletechnique and selected key alloys Phase relationships andsolubility limits have been determined for the ternary andbinary compounds The previously reported ternary com-pound T3 was confirmed in the current study and is denotedas 1205912in this paper Two new ternary compounds 120591

1and 1205913

have been found in this system at 400∘C 1205911does not show

significant solubility ranges and is considered stoichiometric1205913is a solid solution with a narrow homogeneity range

The formulae of the three Al-Mn-Zn ternary intermetalliccompounds are 120591

1 Al31Mn8Zn11 1205912 Al72Mn16Zn12 and 120591

3

Al119909Mn119910Zn119911(119909 = 9ndash13 at 119910 = 11ndash15 at 119911 = 75ndash77 at) A

single-phase region of Al8Mn5with extended solubility was

found in this system at 400∘C Based on the current findingsthe ternary solubilities of the Al

8Mn5 Al4Mn and Al

11Mn4

compounds have been determined as 10 at 6 at and 4 atZn respectively 120576 and Mn

5Zn21

exhibit their maximumsolubilities of 4 at and 5 at Al The solubility of Zn in120573-Mn1015840 has been found to be 4 at and 120573-Mn10158401015840 has ternarysolubility of 3 at Al

Mole

frac

tion

Al

0 20 40 60 80 100

0

20

40

60

80

100 0

20

40

60

80

100

Single-phase regionTwo-phase region

Mole fraction M

n

Zn

Mn

AlMole fraction Zn

400∘C

Al8Mn5

Al 8Mn 5

Al6MnAl4Mn

120573-Mn998400 120573-M

n998400

120573-Mn998400998400

Al11Mn4

Al12Mn MnZn13MnZn9

Mn5Zn21

120576

Three-phase region

1205912 1205911

Al-f

cc

Liqu

idZn

-HCP

120573-Mn998400 + 120573-Mn998400998400

120573-Mn 998400+ 120573-Mn 998400998400

+ 120576

Al8Mn5 + 120573- Mn998400

Al8Mn5 + 120576Al8Mn

5 + Mn5Zn

21 + 1205913

Al8Mn5 + Al11Mn4 + 12059131205911 + Al11Mn4 + 1205913

1205911 + Al-fcc + 1205913

Al8Mn5 + 120573-Mn 998400

+ 120576

Figure 14 Isothermal section of Al-Mn-Zn ternary system at 400∘Cconstructed by diffusion couples and key samples

Conflict of Interests

The authors declare that there is no conflict of interestsof any sort that might have influenced the discussions orconclusions of this paper

Acknowledgments

Financial support from General Motors of Canada Ltd andthe Natural Sciences and Engineering Research Councilof Canada (NSERC) through the CRD grant program isgratefully acknowledged The authors would also like toacknowledge the help of Mohammad Mezbahul-Islam ofMechanical Engineering Department Concordia Universityfor his valuable suggestions

References

[1] G S Cole and A M Sherman ldquoLight weight materials forautomotive applicationsrdquo Materials Characterization vol 35no 1 pp 3ndash9 1995

[2] S W Nam and B O Kong ldquoDevelopment of weldable highstrength alalloyrdquo KOSEF Technical Report 1993

[3] H S Cho and S W Nam ldquoA study of the low cycle fatigueproperties of weldable Al-Zn-Mg-Mn Alloy and Al 7039 invarious environmentsrdquo Journal of Korean Institute of Metals andMaterials vol 32 no 7 pp 765ndash770 1994

[4] M Ohno D Mirkovic and R Schmid-Fetzer ldquoLiquidus andsolidus temperatures of Mg-rich Mg-Al-Mn-Zn alloysrdquo ActaMaterialia vol 54 no 15 pp 3883ndash3891 2006

[5] N Gao Y H Liu and N-Y Tang ldquoAn experimental study ofthe liquid domain of the Zn-Fe-Al-Mn quaternary system at

Journal of Materials 13

460∘Crdquo Journal of Phase Equilibria and Diffusion vol 31 no 6pp 523ndash531 2010

[6] M A Khan and M Medraj ldquoThermodynamic descriptionof the Mg-Mn Al-Mn and Mg-Al-Mn systems using themodified quasichemical model for the liquid phasesrdquoMaterialsTransactions vol 50 no 5 pp 1113ndash1122 2009

[7] C Muller H Stadelmaier B Reinsch and G Petzow ldquoMet-allurgy of the magnetic 120591-phase in Mn-Al and Mn-Al-CrdquoZeitschrift fuer Metallkunde vol 87 no 7 pp 594ndash597 1996

[8] A Shukla and A D Pelton ldquoThermodynamic assessment of theAl-Mn andMg-Al-Mn systemsrdquo Journal of Phase Equilibria andDiffusion vol 30 no 1 pp 28ndash39 2009

[9] H Kono ldquoOn the ferromagnetic phase in manganese-aluminum systemrdquo Journal of the Physical Society of Japan vol13 no 12 pp 1444ndash1451 1958

[10] W Koster and E Wachtel ldquoConstitution and magnetic proper-ties of aluminum-manganese alloyswithmore than 5AtMnrdquoZeitschrift fuer Metallkunde vol 51 pp 271ndash280 1960

[11] Y Minamino T Yamane H Araki et al ldquoSolid solubilities ofmanganese and titanium in aluminum at 01 MPa and 21 GPardquoMetallurgical Transactions A vol 22 no 3 pp 783ndash786 1991

[12] H Okamoto ldquoAl-Mn (Aluminum-Manganese)rdquo Journal ofPhase Equilibria vol 18 no 4 pp 398ndash399 1997

[13] M A Taylor ldquoIntermetallig phases in the aluminiumman-ganese binary systemrdquo Acta Metallurgica vol 8 no 4 pp 256ndash262 1960

[14] S Wasiur-Rahman andMMedraj ldquoA thermodynamic descrip-tion of the Al-Ca-Zn ternary systemrdquoCalphad vol 33 no 3 pp584ndash598 2009

[15] H Okamoto and L E Tanner ldquoThe Mn-Zn (Manganese-Zinc)systemrdquo Bulletin of Alloy Phase Diagrams vol 11 no 4 pp 377ndash384 1990

[16] S Tezuka S Sakai and Y Nakagawa ldquoFerromagnetism of Mn-Zn alloyrdquo Journal of the Physical Society of Japan vol 15 no 5p 931 1960

[17] Y Nakagawa and T Hori ldquoMagnetic transition and crystaldistortion in MnHg andMnZn

3

rdquo Journal of the Physical Societyof Japan vol 17 no 8 pp 1313ndash1314 1962

[18] B Henderson and R J M Willcox ldquoLattice spacing relation-ships in hexagonal close-packed Silver-Zinc-Manganese alloysrdquoPhilosophical Magazine vol 9 no 101 pp 829ndash846 1964

[19] R A Farrar and H W King ldquoAxial ratios and solubility limitsof HCP 120578 and 120576 phases in the systems CdMn and ZnMnrdquoMetallography vol 3 no 1 pp 61ndash70 1970

[20] J L Liang Y Du C Z Liao et al ldquoExperimental investigationon the phase equilibria of the Mn-Ni-Zn system at 400∘CrdquoJournal of Alloys and Compounds vol 489 no 2 pp 362ndash3682010

[21] J L Liang Y Du Q Z Zhao et al ldquoDetermination of the phaseequilibria in the Mn-Sn-Zn system at 500∘ Crdquo MetallurgicalandMaterials Transactions A PhysicalMetallurgy andMaterialsScience vol 40 no 12 pp 2909ndash2918 2009

[22] H Xu X Xiong L Zhang YDu and PWang ldquoPhase equilibriaof the Mn-Si-Zn system at 600∘Crdquo Metallurgical and MaterialsTransactions A Physical Metallurgy and Materials Science vol40 no 9 pp 2042ndash2047 2009

[23] E Gebhardt ldquoDie zinkecke des dreistoffsystems zink-aluminium-manganrdquo Zeitschrift fur Metallkunde vol 34pp 259ndash263 1942

[24] G V Raynor and D W Wakeman ldquoThe intermetallic com-pound phases of the system Aluminium-Manganese-Zincrdquo

Proceedings of the Royal Society of London A Mathematical andPhysical Sciences vol 190 no 1020 pp 82ndash101 1947

[25] K Robinson ldquoThe determination of the crystal structure ofNi4

Mn11

Al60

rdquo Acta Crystallographica vol 7 part 6-7 pp 494ndash497 1954

[26] A Damjanovic ldquoThe structure analysis of the T3

(A1MnZn)compoundrdquo Acta Crystallographica vol 14 pp 982ndash987 1961

[27] R J Schaefer L A Bendersky D Shechtman W J Boettingerand F S Biancaniello ldquoIcosahedral and decagonal phase forma-tion in Al-Mn Alloysrdquo Metallurgical transactions A vol 17 no12 pp 2117ndash2125 1986

[28] A Singh S Ranganathan and L A Bendersky ldquoQuasicrys-talline phases and their approximants inAl-Mn-Zn alloysrdquoActaMaterialia vol 45 no 12 pp 5327ndash5336 1997

[29] J S Kirkaldy and L C Brown ldquoDiffusion behavior in theternarymultiphase systemsrdquoCanadianMetallurgicalQuarterlyvol 2 no 1 pp 90ndash115 1963

[30] J B Clark ldquoConventions for plotting the diffusion paths inmultiphase ternary diffusion couples on the isothermal sectionof a ternary phase diagramrdquo Transactions of the MetallurgicalSociety of AIME vol 227 pp 1250ndash1251 1963

[31] A A Kodentsov G F Bastin and F J J van Loo ldquoThe diffusioncouple technique in phase diagram determinationrdquo Journal ofAlloys and Compounds vol 320 no 2 pp 207ndash217 2001

[32] M A Khan Thermodynamic modeling of the MgndashMnndash(Al Zn)systems [MS thesis] Concordia University 2009

[33] PANalytical Ver22b (222) PANalytical Almelo The Nether-lands 2006

[34] H Putz and K Brandenburg Pearsonrsquos Crystal Data CrystalStructure Database for Inorganic Compounds CD-ROM Soft-ware Version 13

[35] P Ghosh and M Medraj ldquoThermodynamic calculation of theMg-Mn-Zn and Mg-Mn-Ce systems and re-optimization oftheir constitutive binariesrdquo Calphad Computer Coupling ofPhase Diagrams andThermochemistry vol 41 pp 89ndash107 2013

[36] A Prince Alloy Phase Equilibria Elsevier Amsterdam TheNetherland 1966

[37] L Y H John ldquoSchreinemakers rule as applied to non-degenerate ternary systemsrdquoThe Journal of Young Investigatorsvol 19 no 11 2009

Submit your manuscripts athttpwwwhindawicom

ScientificaHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CorrosionInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Polymer ScienceInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CeramicsJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CompositesJournal of

NanoparticlesJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

International Journal of

Biomaterials

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

NanoscienceJournal of

TextilesHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Journal of

NanotechnologyHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

CrystallographyJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CoatingsJournal of

Advances in

Materials Science and EngineeringHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Smart Materials Research

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

MetallurgyJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

BioMed Research International

MaterialsJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Nano

materials

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal ofNanomaterials

2 Journal of Materials

was studied by Gebhardt [23] Later Raynor and Wakeman[24] synthesized three ternary compounds (T1 Al

24Mn5Zn

T2 Al9Mn2Zn and T3 Al

11Mn3Zn2) using electrolytic

deposition and not by alloying They [24] pointed out thatAl4Mn dissolves up to 52 wt Zn whereas Al

6Mn dissolves

only 078wt Zn These two compounds were characterizedbased on the substitution of Mn by Zn atoms Subsequentlyseveral researchers [25ndash28] focused on the crystal structuralanalysis of the ternary compounds reported by Raynor andWakeman [24] Robinson [25] found that T1 was C-centeredorthorhombic phase with 119886 = 248 119887 = 251 and 119888 =303 nm lattice parameters The structure of T3 was found byDamjanovic [26] which also has C-centered orthorhombicunit cell with 119886 = 778 119887 = 238 and 119888 = 126 nm latticeparameters Schaefer et al [27] showed that addition of Znto Al-Mn alloys promoted the formation of decagonal phaseSingh et al [28] used TEM to examine the formation andthe approximant structures of Al

24Mn5Zn and Al

12Mn29Zn

(close to T3 phase) quasicrystals in melt-spun conditionThey [28] observed that melt spinning could lead to theformation of icosahedral phase in Al

24Mn5Zn and decagonal

phase in Al12Mn29Zn Up to now the experimental phase

equilibrium information and thermodynamic data are insuf-ficient for the accurate description of this system Thereforeexperimental investigations of the phase equilibrium in theAl-Mn-Zn ternary system are specifically performed in thepresent work to provide the phase relationships in this systemat 400∘C

2 Experimental Procedures

Diffusion couple technique is a powerful and efficient tool forphase diagram determination [29ndash31] The layer formationin diffusion couples represents the local equilibria at theinterfaces Ternary diffusion couples may contain two phasesin one layer because of the additional degree of freedom[31] Thus three-phase equilibria can be determined atthe interfaces of such layers However ternary diffusioncouples have unpredictable diffusion paths that can lead toomitting some phases Moreover slow kinetic formation ofsome phases may cause the formation of extremely thinlayers that might be difficult to be successfully analyzedTherefore key alloys are used to verify the phase relationshipsobtained from diffusion couple experiments In this workthe experimental procedure was based on the combinationof diffusion couple and key alloys techniques The startingmaterials for both diffusion couples and key alloys were Alingots with purity 997 Zn rods with purity 9999 andMn pieces with purity 99 All of which were suppliedby Alfa Aesar A Johnson Matthey Company Alloys wereprepared in an induction-melting furnace with a Ta crucibleunder an argon protective atmosphere All samples wereremelted three times to assure homogeneityThe actual globalcomposition of the prepared samples was determined byinductively coupled plasmaoptical emission spectrometry(ICPOES) The specimens for ICP analysis were taken from3 different locations of the sample to assure the accuracy ofthe analysis

Table 1 Terminal compositions of diffusion couples along withannealing time

Diffusion couple number End-members Annealing timeDC1 Al-Mn

11

Zn89

30 daysDC2 Mn-Al

94

Zn6

15 and 25 daysDC3 Al-Mn

13

Zn87

30 daysDC4 Mn-Al

65

Mn30

Zn5

30 daysDC5 Al-Mn

32

Zn68

30 days

00 02 04 06 08 10

00

02

04

06

08

10 00

02

04

06

08

10

Mole fraction M

n

Al Zn

Mn

Mole

frac

tion

Al

Mole fraction ZnAl-f

cc

Liqu

idZn

-HCP

Diffusion couplesActual compositions of key samples

Al8Mn5

Al6MnAl4Mn

120573-Mn998400 120573-Mn998400998400

Al11Mn4

Al12MnMnZn13

MnZn9Mn5Zn21

120572-Mn

120576

Figure 1 Terminal compositions of diffusion couples and actualcompositions of key alloys

Preliminary study was carried out using three diffusioncouples DC 1 to 3 Diffusion couples were prepared by grind-ing down the contacting interfaces using 1200 grit SiC paperand then polished up to 1 120583m using alcohol-based diamondsuspension 99 pure ethanol was used as lubricant Theselected end-members were carefully pressed and clampedtogether using a stainless steel ring placed in a Ta containerand sealed in a quartz tube under vacuum atmosphere Theencapsulated samples were then annealed at 400∘C for 4weeks After obtaining preliminary results from the first threediffusion couples two more diffusion couples (DC 4 and 5)and seventeen key alloys (1 to 17) were prepared to obtainthe main phase relationships The composition of the end-members used in diffusion couples are listed in Table 1 Theselection of these end-members was based on preliminarythermodynamic calculations using the models of the binarysystems reported by [6 14 32] The probable diffusion pathswere expected to cross several phase regions which couldlead to formation of large number of the diffusion layersThe compositions of the selected key alloys and the terminalcomposition of the diffusion couples are plotted in Figure 1

Journal of Materials 3

In order to identify the minor inconsistencies the final studywas preceded by preparing another nine key samples (18 to26) All the key alloys were annealed at 400∘C for 4 weeks

The selection of annealing temperature is based on thehomogenization time of alloys and theirmelting temperatureThe annealing temperature should be high enough for fasthomogenization interdiffusion and kinetics in the alloysMeanwhile the annealing temperature should be lower thanthe melting temperature of the alloys The lowest eutectictemperature in this system is around 390∘C in Zn-richcorner However this work is focused on Al-alloys and allsamples were prepared away from Zn-rich corner Therefore400∘C was selected in order to have faster interdiffusion andrelatively shorter annealing time

Key alloys and diffusion couples were investigated usingelectron probe microanalysis (EPMA) and scanning elec-tron microscopy (SEM) equipped with energy dispersiveX-ray spectroscopy (EDS) The microstructure and phasecomposition of the samples were analyzed either by EPMA(JOEL-JXA-8900) or SEMEDS (HITACHI S-3400N) Thedifference between EPMA and SEMEDS results was lessthan 2 at for Mn This value was obtained by comparingthe composition of several samples using both techniquesX-ray diffraction (XRD) was used for phase analysis of thekey alloys and for the determination of the solubility limitsof the compounds The XRD patterns were obtained usingPANanalytical Xpert Pro powder X-ray diffractometer [33]with a CuK120572 radiation at 45 kV and 40mA X-ray diffractionanalysis of the samples was carried out using XrsquoPert High-Score Plus Rietveld analysis software [33] Pearsonrsquos crystaldatabase [34] was used to identify the known phases in theAl-Mn-Zn system

3 Results and Discussion

31 Experimental Study of Diffusion Couples Isothermalsection of the Al-Mn-Zn ternary system was constructedbased on the experimental results of 5 diffusion couplesand 26 key samples shown in Figure 1 During the prelimi-nary study three ternary compounds 120591

1(Al31Mn8Zn11) 1205912

(Al71Mn16Zn13) and 120591

3(Al10Mn15Zn75) have been found

through diffusion couples analysisBackscattered electron image of DC 1 (Al-Mn

11Zn89) is

presented in Figure 2(a) Half of the image is colored forbetter representation of diffusion layers in this diffusion cou-ple The interdiffusion took place which led to the formationof several diffusion layers The compositions of the formedphases were determined using EPMA point analysis EPMAline-scan was used to determine the solubility ranges andphase equilibria among intermetallics Based on the compo-sition profile obtained by EPMA as shown in Figure 2(b)the diffusion path was depicted based on the sequence ofthe phases as Mn

5Zn21rarr Al

8Mn5rarr Al

11Mn4rarr

1205911rarr Al-fcc New ternary intermetallic compound 120591

1has

been found in this diffusion couple 1205911was determined as a

compound with the composition of Al62Mn16Zn22 As can

be seen from Figure 2(b) the three points of EPMA resultsshow no solubility range of 120591

1 Additional key alloy analysis

was consistent with the results of DC 1 (Al-Mn11Zn89)

This is why this compound is considered as stoichiometricFigure 2(c) shows the estimated diffusion path of DC 1 (Al-Mn11Zn89) plotted on the Al-Mn-Zn Gibbs triangle Layer

number 1 was determined asMn5Zn21 The solubility of Al in

Mn5Zn21

was measured as 5 at where Al atoms substituteZn atoms and Mn content remains constant at 16 at Basedon the local equilibrium at the Mn

5Zn21Al8Mn5interface

Mn5Zn21

is in equilibrium with Al8Mn5 In layer number

2 Al8Mn5solid solution dissolves up to 7 at Zn as shown

in Figure 2(b) This homogeneity range was also confirmedby DC 4 (Mn-Al

65Mn30Zn5) DC 5 (Al-Mn

32Zn68) and key

alloys 13ndash17The composition of Al8Mn5did not vary in DC 1

(Al-Mn11Zn89) because the diffusion path changed direction

to form Al11Mn4layer Layer number 3 was determined as

Al11Mn4with limited ternary solubility of around 2 at Zn

This value can be considered negligible because the estimatederror of EPMAmeasurement is about 2 at Layer number 4contains two phases these are Al

11Mn4and 1205911 The results of

point analysis indicated that Al11Mn4has negligible ternary

solubility and 1205911has the composition of Al

62Mn16Zn22 Layer

number 5 was identified as 1205911 Results of line-scan across

1205911layer showed that the composition of 120591

1is constant as

Al62Mn16Zn22 In layer number 6 Al-fcc was in equilibrium

with 1205911 The solubility of Zn in Al-fcc was found to reach up

to 20 at based on the EPMA line-scan resultsDC 2 (Mn-Al

94Zn6) was annealed at 400∘C for two

different time periods (15 and 25 days) in order to understandthe phase formation kinetics The annealing time resultedin significant growth of some compounds at the expense ofothersThis can be clearly seen in Figures 3(a) and 3(b) wherethe layer thickness of Al

11Mn4is growing at the expense of

Al4Mn and 120591

2 Six layers were observed in this diffusion cou-

ple for both annealing times The sequence of the observedphases is represented as follows Al-fcc rarr 120591

2rarr Al

4Mn rarr

Al11Mn4rarr Al

8Mn5rarr 120573-Mn1015840 rarr 120573-Mn10158401015840 rarr Mn The

ternary compound T3 (Al11Mn3Zn2) reported by [24] was

observed in this diffusion couple and is denoted as 1205912in this

paper as shown in Figures 3(a) and 3(b) 1205912was determined

as Al71Mn16Zn13 which is close to the composition of T3

(Al69Mn19Zn12) as reported byRaynor andWakeman [24] In

DC 2 (Mn-Al94Zn6) finger-like structuremorphology can be

observed after annealing for 15 days as shown in Figure 3(b)This type of morphology indicates anisotropic diffusion ofthe three elements in this system Al

11Mn4showed higher

growth rate compared to other phases in this diffusion coupleThis was concluded by comparing the micrographs of DC 2(Figures 3(a) and 3(b)) Both thicknesses of 120591

2and Al

4Mn

decreased after annealing for additional 10 days as shown inFigure 3(b) The Mn content of Al

4Mn was found to vary

from 18 at to 20 at after annealing for 15 days whereas itbecame constant at 20 atMnafter annealing for 25 daysThesolubility of Zn in Al

4Mn was measured as 5 at SEMEDS

analysis of DC 2 (Mn-Al94Zn6) annealed for 25 days is

presented in Figure 3(c) The solubility of Zn in Al8Mn5was

measured as 5 at The ternary solid solubility of 120573-Mn1015840 wasfound to be 4 at Zn 120573-Mn10158401015840 shows limited ternary solubilityof 3 at Al

4 Journal of Materials

Al-fcc

Line-scan

1 2 3 4 5 6

Al8Mn5 Al11Mn4 1205911Mn5Zn21 Al11Mn4 + 1205911

15120583m

(a)

0 2 4 6 8 10 12 14 16 18 20 22 240

102030405060708090

100

Al-fcc

Elem

ents

(at

)

Points number

ZnMnAl

Al8Mn5 Al11Mn4 1205911Mn5Zn21

(b)

4

6

5

3

2

Composition of detected phases

Mole fraction M

nMole

frac

tion

Al

Zn0 20 40 60 80 100

0

20

40

60

80

100 0

20

40

60

80

100

Mn

Al

Mole fraction Zn

DC 1

Diffusion path

1

6 Al-fcc layer

Al8Mn5

Al6MnAl4Mn

120573-Mn998400 120573-Mn998400998400

Al11Mn4

Al12MnMnZn13

MnZn9Mn5Zn21

120576

400∘C

1 Mn5Zn21 layer2 Al8Mn5 layer3 Al11Mn4 layer

4 Al11Mn4 + 1205911 layer5 1205911 layer

Al-f

cc

Liqu

idZn

-HCP

(c)

Figure 2 (a) Backscattered electron image of DC 1 (Al-Mn11

Zn89

) and its schematic (b) composition profile of the line-scan in DC 1 (Al-Mn11

Zn89

) (c) approximation of diffusion path of DC 1 (Al-Mn11

Zn89

)

Journal of Materials 5

Al8Mn5

Al4MnMn 120573-Mn998400

120573-Mn998400998400

Al11Mn4

Al-fcc1205912

(a)

Al8Mn5

Al4MnMn

120573-Mn998400

120573-Mn998400998400

Al11Mn4

Al-fcc

1205912

(b)

0 20 40 60 80 100

0

20

40

60

80

100 0

20

40

60

80

100

Composition of detected phases

Mole fraction M

nMole

frac

tion

Al

Zn

Mn

Al

Diffusion path

DC2

25 days

Mole fraction Zn

400∘C

Al8Mn5

Al6MnAl4Mn

120573-Mn998400 120573-Mn998400998400

Al12MnMnZn13

MnZn9Mn5Zn21

120576

1205912

Al11Mn4

Al-f

cc

Liqu

idZn

-HCP

(c)

Mole

frac

tion

Al

0 20 40 60 80 100

0

20

40

60

80

100 0

20

40

60

80

100

15 days25 days

Mole fraction M

n

Zn

Mn

Al

Mole fraction Zn

400∘C

Al8Mn5

Al6MnAl4Mn

120573-Mn998400 120573-Mn998400998400

Al11Mn4

Al12MnMnZn13

MnZn9Mn5Zn21

120576

1205912

Al-f

cc

Liqu

idZn

-HCP

(d)

Figure 3 (a) Backscattered electron image of DC 2 (Mn-Al94

Zn6

) annealed at 400∘C for 15 days along with its schematic (b) backscatteredelectron image of DC 2 (Mn-Al

94

Zn6

) annealed at 400∘C for 25 days along with its schematic (c) diffusion path of DC 2 (Mn-Al94

Zn6

)annealed for 25 days (d) comparisons of DC 2 (Mn-Al

94

Zn6

) annealed at 15 days and 25 days

Al-fcc

Al4Mn

50120583m

1205911

Figure 4 Backscattered electron image of sample 1

DC 3 (Al-Mn13Zn87) was studied using the same

approach as for DC 1 (Al-Mn11Zn89) and DC 2 (Mn-

Al94Zn6) Four phases have been identified through EPMA

analysis 1205913 Al8Mn5 Al11Mn4 and Al-fcc EPMA point

analysis indicated that the 1205913ternary compound had the

composition of Al10Mn15Zn75 Other than this the results of

this diffusion couple only confirmed the data obtained fromDC 1 and 2Therefore the details of DC 3 (Al-Mn

13Zn87) are

not mentioned here to avoid repetition

32 Experimental Study of Key Alloys Ten key alloys wereprepared to verify the formation of phases reported in theliterature and confirm the presence of the ternary compounds1205911 1205912 and 120591

3found in this experimental study The actual

6 Journal of Materials

Al-fcc

Al4Mn

Al6Mn

20120583m

(a)

Al-fcc

Al4Mn

Al6Mn

(b)

Figure 5 (a) Backscattered electron image of as-cast sample 7 (b) backscattered electron image of annealed sample 7

30 35 40 45 50 55 60 65 70 75 80 850

50

100

150

200

250

Al 148

Cou

nts

Position of 2120579

Al4Mn 562

Al6Mn 29

(a)

30 35 40 45 50 55 60 65 70 75 80 850

100

200

300

400

500

Cou

nts

Al 108

Position of 2120579

Al4Mn 14

Al6Mn 752

(b)

Figure 6 (a) XRD spectrum of as-cast sample 7 (b) XRD spectrum of annealed sample 7

Al4Mn Al-fcc

1205912

Figure 7 Backscattered electron image of sample 3

composition of these key alloys and the composition of thedetected phases are presented in Table 2

The ternary compounds T1 (Al24Mn5Zn) and T2

(Al9Mn2Zn) [24] were not observed in this system at 400∘C

As shown in Table 2 key alloy 7 was prepared close tothe composition of T1 compound key alloys 5 and 6 weremade close to the composition of T2 compound HoweverT1 and T2 were not detected It should be mentioned thatRaynor and Wakeman [24] used only as-cast samples intheir study and reported compounds could be metastable orhigh temperature phases Furthermore they [24] have usedthe wet chemical analysis of small quantities of extractedcrystals which may cause errors in phase compositionsdetermination compared to EPMA point analysis usedin our work The existence of 120591

1phase was confirmed in

sample 1 as a stoichiometric compound with Al64Mn15Zn21

composition The microstructure of this alloy is shown inFigure 4 120591

1formed during a peritectic reaction which is hard

to be terminated during short annealing period Thereforethe primary phase Al

4Mn was not decomposed completely

even after annealing for 30 days Similar phenomenon wasalso observed in key sample 7 Figures 5(a) and 5(b) showthe as-cast and annealed microstructures of sample 7 It isclear that Al

4Mn (the white phase) formed as a primary

phase Al6Mn then formed according to the peritectic

reaction L + Al4Mn rarr Al

6Mn After annealing for 30 days

Journal of Materials 7

Table 2 The actual compositions of the key samples and the detected phases

Samplenumber

Actual compositionidentified by ICP (at) Phase identification

Composition ofidentified phasesby EPMA (at)

Al Mn Zn ByEPMA

ByXRD Al Mn Zn

1 44 16 40Al4Mn Al4Mn 74 20 61205911

64 15 21Al-fcc Al-fcc 55 0 45

2 75 13 121205912

1205912

73 15 12Al4Mn Al4Mn 74 20 6Al-fcc Al-fcc 78 0 22

3 78 15 71205912

1205912

75 14 11Al4Mn Al4Mn 75 20 5Al-fcc Al-fcc 88 0 12

4 79 10 111205912

1205912

72 16 12Al4Mn Al4Mn 76 20 4Al-fcc Al-fcc 79 0 21

5 74 16 101205912

1205912

73 15 12Al4Mn Al4Mn 74 20 6Al-fcc Al-fcc 75 0 25

6 74 15 111205912

1205912

72 15 13Al4Mn Al4Mn 74 20 6Al-fcc Al-fcc 80 0 20

7 84 12 4Al6Mn Al6Mn 86 14 0Al4Mn Al4Mn 75 20 5Al-fcc Al-fcc 95 0 5

8 82 11 7Al12Mn 92 8 0Al6Mn 83 15 2Al-fcc 96 0 4

9 21 14 651205913

12 11 77Al11Mn4 Al11Mn4 70 26 3Al8Mn5 Al8Mn5 56 37 7

10 16 14 701205913

12 11 771205914

23 16 61Al11Mn4 Al11Mn4 71 25 4

11 23 16 61

1205913

13 13 741205914

25 18 57Al11Mn4 Al11Mn4 69 27 4Al8Mn5 Al8Mn5 55 36 9

12 17 15 68Al11Mn4 Al11Mn4 70 26 41205913

13 11 761205914

23 16 61

13 18 22 60 1205913

10 15 75Al8Mn5 Al8Mn5 52ndash57 33ndash37 10ndash11

14 64 31 5 Al11Mn4 Al11Mn4 70 26 4Al8Mn5 Al8Mn5 55 34 10

15 56 37 7 Al8Mn5 Al8Mn5 57 39 4

16 55 35 10 Al11Mn4 Al11Mn4 70 27 3Al8Mn5 Al8Mn5 57 34 9

17 30 35 35 Al8Mn5 54 38 8120576 74 22 4

8 Journal of Materials

(a)

Al8Mn5

Al11Mn4

1205913

(b)

Al11Mn4

1205913

1205914

10120583m

(c)

Al11Mn4

1205913

100120583m

(d)

Figure 8 (a) Backscattered electron image of annealed sample 9 at 400∘C for 30 days (b) magnified area of sample 9 (c) backscatteredelectron image of sample 10 annealed at 400∘C for 25 days (d) backscattered electron image of sample 10 annealed at 400∘C for 40 days

30 35 40 45 50 55 60 65 70 75 800

50100150200250300350400450500550600650700

Al

Cou

nts

Position of 2120579

Al4Mn1205911

Figure 9 XRD spectrum of annealed sample 1

the amount of Al4Mn decreased and decomposed to Al

6Mn

The microstructure of annealed sample 7 is shown inFigure 5(b) Using XRD analysis the weight fraction ofAl4Mn and Al

6Mn in the as-cast sample was measured

as 562 and 29 respectively as shown in Figure 6(a)

The amount of Al4Mn and Al

6Mn changed dramatically

after annealing for 30 days to become 14 and 822as demonstrated in Figure 6(b) This variation indicatesperitectic decomposition upon annealing Due to the naturalsluggish kinetics of peritectic reaction the transformation ofAl4Mn to Al

6Mn requires very long time

The formation of 1205912was confirmed after analysis of key

alloys 2 to 6 The microstructure of sample 3 is shown inFigure 7 EPMA results indicated that 120591

2is a stoichiometric

compound with Al71Mn16Zn13

composition It has beenobserved that the Mn content of Al

4Mn varies in the range of

18ndash21 at which could be owing to the Zn substitution Thedissolved Zn in Al

4Mn was found to reach up to 6 at Sub-

stitution of third element could lead to the small variationsof compositions On the other hand these Mn content devia-tions could be due to the fact that Al

4Mn forms quasicrystals

The structure of quasicrystal may change under differentsolidification conditions [27] Schaefer et al [27] mentionedthat Al

4Mn formed icosahedral or decagonal quasicrystals

and structural changes in solid solutions could affect the com-positions They [27] observed that composition of ternaryquasicrystals most likely fall in the range of 18ndash22 at Mnwhich was close to the composition region of the stable 120583-Al4Mn phase The composition of reported T1 is close to

Journal of Materials 9

30 35 40 45 50 55 60 65 70 75 800

50

100

150

200

250

300

350C

ount

s

Position of 2120579

(a)

30 35 40 45 50 55 60 65 70 75 800

50

100

150

200

250

300

350

Cou

nts

Position of 2120579

(b)

30 35 40 45 50 55 60 65 70 75 800

50

100

150

200

250

300

Cou

nts

SiAl

Position of 2120579

Al4Mn1205912

(c)

Figure 10 (a) XRD spectrum of annealed sample 2 (b) XRD spectrum of annealed sample 3 (c) XRD spectrum of annealed sample 5

the homogeneity range of Al4Mn which indicated that T1

might be a quasicrystal of Al4Mnwith extended Zn solubility

1205913was observed in DC 3 (Al-Mn

13Zn87) and the com-

position was primarily determined as Al10Mn15Zn75 Several

key alloys were prepared to study this new compound Theactual compositions of these samples and the compositionsof the detected phases are listed in Table 2 The 120591

3phase has

a complex homogeneity range 9ndash13 at Al 11ndash15 at Mnand 75ndash77 at Zn as was determined by the analysis of DC3 (Al-Mn

13Zn87) and key samples 9 to 13 Sample 9 is an

example of these findings as shown in Figures 8(a) and 8(b)The sample contains residuals of the primary Al

8Mn5phase

that decomposes according to the peritectic reaction L+Al8Mn5rarr Al

11Mn4 The decomposition of Al

8Mn5was not

complete due to the slow kinetics of the peritectic reaction 1205913

phase formed a matrix in this alloyThe homogeneity ranges of the binary compounds were

determined using EPMA From the EPMA results Al11Mn4

exhibited ternary solubility reaching up to 4 at Zn Al4Mn

had the maximum ternary solubility of 6 at Zn Thedissolved Zn in Al-fcc was found to reach up to 45 atTernary homogeneity range of Al

8Mn5has been determined

by EPMA as 11 atZnThese observations also confirmed theresults which were inferred from DC 4 (Mn-Al

65Mn30Zn5)

Additionally another ternary phase 1205914was found in this

ternary system The composition of this phase is in the

region around Al23Mn16Zn61 However 120591

4is found to be

metastable As shown in Figure 8(c) three phases Al11Mn4

1205913 and 120591

4were found in sample 12 to be annealed at 400∘C

for 25 days After prolonged annealing for another 15 days 1205914

decomposed to provide more 1205913and Al

11Mn4

In order to verify the observations of the ternary com-pounds key alloys were studied using XRD The XRDpatterns of sample 1 are illustrated in Figure 9 Al-fcc andAl4Mn are positively identified in the XRD pattern Besides

there are several peaks which do not belong to any of theknown binary phases in the system Based on the resultsof phase identifications those peaks could correspond to1205911 Because of the lack of the reported prototype of 120591

1 the

peaks which belong to 1205911were hard to separate due to the

several overlapping peaks in the XRD pattern of this sampleThus the crystal structure of this compound could not bedetermined in the current study However the peaks whichcould belong to 120591

1have been labeled as shown in Figure 9

T3 phase reported by [24] denoted as 1205912in the current

study was confirmed through XRD analysis Three XRDspectra of sample 2 3 and 5 were used for this purpose Asshown in Figure 10 the XRD patterns of the three samplesare similar From 2120579 position 40∘ to 45∘ hump-like patternscan be observed due to peaks overlapping This is becauseAl4Mnhas very complex crystal structure and has around 550

atoms in a giant unit cell [34] During the X-ray scanning

10 Journal of Materials

Mn

Al8Mn5Al8Mn5

120573-Mn998400

Al11Mn4

50120583m

(a)

0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 340

10

20

30

40

50

60

70

80

90

100

Elem

ents

(at

)

Points number

MnZn

AlAl8Mn5

Al8Mn5120573-Mn998400

Al11Mn4

Al8Mn5

Al11Mn4

(b)

Figure 11 (a) Backscattered electron image of diffusion couple DC 4 (Mn-Al65

Mn30

Zn5

) (b) composition profile of line-scan in diffusioncouple DC 4 (Mn-Al

65

Mn30

Zn5

)

process the diffracted spectra of Al4Mn were overlapping

with other peaks at numerous positions and generate theseoverlapped patterns Using the crystallographic entry of T3from Pearsonrsquos database [34] T3 was positively identifiedamong XRD analysis Along with Al-fcc and Al

4Mn the

triangulation among those three phases was establishedXRD analysis of ternary compound 120591

3has similar issues

to 1205911as elucidated above Unfortunately too many peaks

were overlapping in a multiphase alloy and a single-phasesample representing 120591

3was not possible to prepareTherefore

the crystal structure of this compound has not been deter-mined either

33 Description of Ternary Solid Solutions

331 Homogeneity Range of Al8Mn5and Al

11Mn4 Al8Mn5

has wide homogeneity range in Al-Mn binary system How-ever it is difficult to estimate how much of Zn dissolvedin this compound from the results of DC 2 (Mn-Al

94Zn6)

Journal of Materials 11

Al8Mn5

Al11Mn4

80120583m

(a)

Al8Mn5

50120583m

(b)

20 25 30 35 40 45 50 550

100

200

300

400

500

600

Cou

nts

Position of 2120579

Al8Mn5

98 Al8Mn5

(c)

Figure 12 (a) Backscattered electron image of sample 14 (b) backscattered electron image of sample 15 (c) XRD spectrum of sample 15

Thus DC 4 (Mn-Al65Mn30Zn5) was prepared in order to

determine the homogeneity range of Al8Mn5in this ternary

system Because Al11Mn4has higher growth rate one end

member of DC 4 (Mn-Al65Mn30Zn5) has been selected near

the Al8Mn5region to increase the atomic exchange between

Al and Mn From the backscattered electron image of DC4 (Mn-Al

65Mn30Zn5) shown in Figure 11(a) Al

8Mn5formed

a thick layer and the color changed along with decreasingMn content which suggests the presence of a homogeneityrange Line-scan shown in Figure 11(b) was carried outto determine the homogeneity range of Al

8Mn5 In the

Al11Mn4+ Al8Mn5two-phase region dotted lines denote

the concentrations of elements in Al11Mn4and solid lines

represent the concentrations of elements in Al8Mn5 The

SEMEDS analysis showed that Al8Mn5has ternary solubility

of 9 at Zn and Al11Mn4has maximum ternary solubility

of 4 at Zn Al concentration in Al8Mn5layer varied from

49 at to 58 atAl11Mn4and Al

8Mn5showed extended ternary solubility

in this system at 400∘C In order to confirm the resultsobtained from previous diffusion couples four key alloys(14 to 17) were prepared The composition and phase iden-tification of these key samples are summarized in Table 2The phase relations obtained from EPMA showed greatconsistency with the XRD results Backscattered electronimage of sample 14 is shown in Figure 12(a) From EPMA

point analysis Al11Mn4has a ternary solubility of about 4 at

Zn and Al8Mn5has a maximum ternary solubility of 10 at

Zn These results were consistent with the previous EPMAobservation of samples 9 and 11 Figure 12(b) shows thatsample 15 contains mainly Al

8Mn5whose ternary solubility

was measured around 4 at Zn The XRD analysis also con-firmed that Al

8Mn5is dominating in sample 15 as shown in

Figure 12(c)There are a few unlabeled small peaks indicatingthe presence of Al

11Mn4traces which could not be identified

in the current study because of their low intensity

332 Single Region of 120576 Phase Controversy on whether120576 has three-phase separations reported in the assessmentof Okamoto and Tanner [15] is still not resolved In thecurrent study one end-member of DC 5 (Al-Mn

32Zn68)

has a composition in the 120576-phase region EPMA line-scanindicated that 120576-phase has continuous binary solubility rangesreaching fromMn

32Zn68to Mn

40Zn60at 400∘CThis finding

also corresponds to the Mn-Zn binary system which wasreported by [32 35] The backscattered electron image of DC5 (Al-Mn

32Zn68) is presented in Figure 13 Five phases have

been identified 120576 Al-rich 120573-Mn1015840 Al8Mn5 Al11Mn4 and Al-

fcc In the current experimental investigation the maximumsolubility of Zn in 120573-Mn1015840 was measured as 4 at Single 120576-phase region with the Mn content from 32 to 40 at was

12 Journal of Materials

Al8Mn5

120573-Mn998400

Al11Mn4

Al-fcc

Mn32Zn68(120576)

Figure 13 Backscattered electron image of DC 5 (Al-Mn32

Zn68

)

observed at 400∘C and nothing indicated the presence ofphase separation in this composition range From the resultsof sample 17 (Al

30Mn35Zn35) 120576-phase was found to have

limited ternary solubility of 4 at Al

34 Isothermal Section of Al-Mn-Zn System at 400∘C Com-bining the results which were obtained from the diffusioncouples with those obtained from the key alloys the Al-Mn-Zn isothermal section at 400∘C was constructed and pre-sented in Figure 14 Solid lines represent the experimentallyverified phase boundaries and ternary solubility of binaryphases Dotted lines are the estimated phase relationshipswhich were not confirmed in the current study They wereconstructed based on the Gibbs phase rule [36] and Schreine-makerrsquos rule [37] Grey blue and green areas indicate thesingle two-phase and three-phase regions separately asshown in Figure 14

4 Conclusion

The Al-Mn-Zn isothermal section at 400∘C was constructedbased on the current experimental results of diffusion coupletechnique and selected key alloys Phase relationships andsolubility limits have been determined for the ternary andbinary compounds The previously reported ternary com-pound T3 was confirmed in the current study and is denotedas 1205912in this paper Two new ternary compounds 120591

1and 1205913

have been found in this system at 400∘C 1205911does not show

significant solubility ranges and is considered stoichiometric1205913is a solid solution with a narrow homogeneity range

The formulae of the three Al-Mn-Zn ternary intermetalliccompounds are 120591

1 Al31Mn8Zn11 1205912 Al72Mn16Zn12 and 120591

3

Al119909Mn119910Zn119911(119909 = 9ndash13 at 119910 = 11ndash15 at 119911 = 75ndash77 at) A

single-phase region of Al8Mn5with extended solubility was

found in this system at 400∘C Based on the current findingsthe ternary solubilities of the Al

8Mn5 Al4Mn and Al

11Mn4

compounds have been determined as 10 at 6 at and 4 atZn respectively 120576 and Mn

5Zn21

exhibit their maximumsolubilities of 4 at and 5 at Al The solubility of Zn in120573-Mn1015840 has been found to be 4 at and 120573-Mn10158401015840 has ternarysolubility of 3 at Al

Mole

frac

tion

Al

0 20 40 60 80 100

0

20

40

60

80

100 0

20

40

60

80

100

Single-phase regionTwo-phase region

Mole fraction M

n

Zn

Mn

AlMole fraction Zn

400∘C

Al8Mn5

Al 8Mn 5

Al6MnAl4Mn

120573-Mn998400 120573-M

n998400

120573-Mn998400998400

Al11Mn4

Al12Mn MnZn13MnZn9

Mn5Zn21

120576

Three-phase region

1205912 1205911

Al-f

cc

Liqu

idZn

-HCP

120573-Mn998400 + 120573-Mn998400998400

120573-Mn 998400+ 120573-Mn 998400998400

+ 120576

Al8Mn5 + 120573- Mn998400

Al8Mn5 + 120576Al8Mn

5 + Mn5Zn

21 + 1205913

Al8Mn5 + Al11Mn4 + 12059131205911 + Al11Mn4 + 1205913

1205911 + Al-fcc + 1205913

Al8Mn5 + 120573-Mn 998400

+ 120576

Figure 14 Isothermal section of Al-Mn-Zn ternary system at 400∘Cconstructed by diffusion couples and key samples

Conflict of Interests

The authors declare that there is no conflict of interestsof any sort that might have influenced the discussions orconclusions of this paper

Acknowledgments

Financial support from General Motors of Canada Ltd andthe Natural Sciences and Engineering Research Councilof Canada (NSERC) through the CRD grant program isgratefully acknowledged The authors would also like toacknowledge the help of Mohammad Mezbahul-Islam ofMechanical Engineering Department Concordia Universityfor his valuable suggestions

References

[1] G S Cole and A M Sherman ldquoLight weight materials forautomotive applicationsrdquo Materials Characterization vol 35no 1 pp 3ndash9 1995

[2] S W Nam and B O Kong ldquoDevelopment of weldable highstrength alalloyrdquo KOSEF Technical Report 1993

[3] H S Cho and S W Nam ldquoA study of the low cycle fatigueproperties of weldable Al-Zn-Mg-Mn Alloy and Al 7039 invarious environmentsrdquo Journal of Korean Institute of Metals andMaterials vol 32 no 7 pp 765ndash770 1994

[4] M Ohno D Mirkovic and R Schmid-Fetzer ldquoLiquidus andsolidus temperatures of Mg-rich Mg-Al-Mn-Zn alloysrdquo ActaMaterialia vol 54 no 15 pp 3883ndash3891 2006

[5] N Gao Y H Liu and N-Y Tang ldquoAn experimental study ofthe liquid domain of the Zn-Fe-Al-Mn quaternary system at

Journal of Materials 13

460∘Crdquo Journal of Phase Equilibria and Diffusion vol 31 no 6pp 523ndash531 2010

[6] M A Khan and M Medraj ldquoThermodynamic descriptionof the Mg-Mn Al-Mn and Mg-Al-Mn systems using themodified quasichemical model for the liquid phasesrdquoMaterialsTransactions vol 50 no 5 pp 1113ndash1122 2009

[7] C Muller H Stadelmaier B Reinsch and G Petzow ldquoMet-allurgy of the magnetic 120591-phase in Mn-Al and Mn-Al-CrdquoZeitschrift fuer Metallkunde vol 87 no 7 pp 594ndash597 1996

[8] A Shukla and A D Pelton ldquoThermodynamic assessment of theAl-Mn andMg-Al-Mn systemsrdquo Journal of Phase Equilibria andDiffusion vol 30 no 1 pp 28ndash39 2009

[9] H Kono ldquoOn the ferromagnetic phase in manganese-aluminum systemrdquo Journal of the Physical Society of Japan vol13 no 12 pp 1444ndash1451 1958

[10] W Koster and E Wachtel ldquoConstitution and magnetic proper-ties of aluminum-manganese alloyswithmore than 5AtMnrdquoZeitschrift fuer Metallkunde vol 51 pp 271ndash280 1960

[11] Y Minamino T Yamane H Araki et al ldquoSolid solubilities ofmanganese and titanium in aluminum at 01 MPa and 21 GPardquoMetallurgical Transactions A vol 22 no 3 pp 783ndash786 1991

[12] H Okamoto ldquoAl-Mn (Aluminum-Manganese)rdquo Journal ofPhase Equilibria vol 18 no 4 pp 398ndash399 1997

[13] M A Taylor ldquoIntermetallig phases in the aluminiumman-ganese binary systemrdquo Acta Metallurgica vol 8 no 4 pp 256ndash262 1960

[14] S Wasiur-Rahman andMMedraj ldquoA thermodynamic descrip-tion of the Al-Ca-Zn ternary systemrdquoCalphad vol 33 no 3 pp584ndash598 2009

[15] H Okamoto and L E Tanner ldquoThe Mn-Zn (Manganese-Zinc)systemrdquo Bulletin of Alloy Phase Diagrams vol 11 no 4 pp 377ndash384 1990

[16] S Tezuka S Sakai and Y Nakagawa ldquoFerromagnetism of Mn-Zn alloyrdquo Journal of the Physical Society of Japan vol 15 no 5p 931 1960

[17] Y Nakagawa and T Hori ldquoMagnetic transition and crystaldistortion in MnHg andMnZn

3

rdquo Journal of the Physical Societyof Japan vol 17 no 8 pp 1313ndash1314 1962

[18] B Henderson and R J M Willcox ldquoLattice spacing relation-ships in hexagonal close-packed Silver-Zinc-Manganese alloysrdquoPhilosophical Magazine vol 9 no 101 pp 829ndash846 1964

[19] R A Farrar and H W King ldquoAxial ratios and solubility limitsof HCP 120578 and 120576 phases in the systems CdMn and ZnMnrdquoMetallography vol 3 no 1 pp 61ndash70 1970

[20] J L Liang Y Du C Z Liao et al ldquoExperimental investigationon the phase equilibria of the Mn-Ni-Zn system at 400∘CrdquoJournal of Alloys and Compounds vol 489 no 2 pp 362ndash3682010

[21] J L Liang Y Du Q Z Zhao et al ldquoDetermination of the phaseequilibria in the Mn-Sn-Zn system at 500∘ Crdquo MetallurgicalandMaterials Transactions A PhysicalMetallurgy andMaterialsScience vol 40 no 12 pp 2909ndash2918 2009

[22] H Xu X Xiong L Zhang YDu and PWang ldquoPhase equilibriaof the Mn-Si-Zn system at 600∘Crdquo Metallurgical and MaterialsTransactions A Physical Metallurgy and Materials Science vol40 no 9 pp 2042ndash2047 2009

[23] E Gebhardt ldquoDie zinkecke des dreistoffsystems zink-aluminium-manganrdquo Zeitschrift fur Metallkunde vol 34pp 259ndash263 1942

[24] G V Raynor and D W Wakeman ldquoThe intermetallic com-pound phases of the system Aluminium-Manganese-Zincrdquo

Proceedings of the Royal Society of London A Mathematical andPhysical Sciences vol 190 no 1020 pp 82ndash101 1947

[25] K Robinson ldquoThe determination of the crystal structure ofNi4

Mn11

Al60

rdquo Acta Crystallographica vol 7 part 6-7 pp 494ndash497 1954

[26] A Damjanovic ldquoThe structure analysis of the T3

(A1MnZn)compoundrdquo Acta Crystallographica vol 14 pp 982ndash987 1961

[27] R J Schaefer L A Bendersky D Shechtman W J Boettingerand F S Biancaniello ldquoIcosahedral and decagonal phase forma-tion in Al-Mn Alloysrdquo Metallurgical transactions A vol 17 no12 pp 2117ndash2125 1986

[28] A Singh S Ranganathan and L A Bendersky ldquoQuasicrys-talline phases and their approximants inAl-Mn-Zn alloysrdquoActaMaterialia vol 45 no 12 pp 5327ndash5336 1997

[29] J S Kirkaldy and L C Brown ldquoDiffusion behavior in theternarymultiphase systemsrdquoCanadianMetallurgicalQuarterlyvol 2 no 1 pp 90ndash115 1963

[30] J B Clark ldquoConventions for plotting the diffusion paths inmultiphase ternary diffusion couples on the isothermal sectionof a ternary phase diagramrdquo Transactions of the MetallurgicalSociety of AIME vol 227 pp 1250ndash1251 1963

[31] A A Kodentsov G F Bastin and F J J van Loo ldquoThe diffusioncouple technique in phase diagram determinationrdquo Journal ofAlloys and Compounds vol 320 no 2 pp 207ndash217 2001

[32] M A Khan Thermodynamic modeling of the MgndashMnndash(Al Zn)systems [MS thesis] Concordia University 2009

[33] PANalytical Ver22b (222) PANalytical Almelo The Nether-lands 2006

[34] H Putz and K Brandenburg Pearsonrsquos Crystal Data CrystalStructure Database for Inorganic Compounds CD-ROM Soft-ware Version 13

[35] P Ghosh and M Medraj ldquoThermodynamic calculation of theMg-Mn-Zn and Mg-Mn-Ce systems and re-optimization oftheir constitutive binariesrdquo Calphad Computer Coupling ofPhase Diagrams andThermochemistry vol 41 pp 89ndash107 2013

[36] A Prince Alloy Phase Equilibria Elsevier Amsterdam TheNetherland 1966

[37] L Y H John ldquoSchreinemakers rule as applied to non-degenerate ternary systemsrdquoThe Journal of Young Investigatorsvol 19 no 11 2009

Submit your manuscripts athttpwwwhindawicom

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Journal ofNanomaterials

Journal of Materials 3

In order to identify the minor inconsistencies the final studywas preceded by preparing another nine key samples (18 to26) All the key alloys were annealed at 400∘C for 4 weeks

The selection of annealing temperature is based on thehomogenization time of alloys and theirmelting temperatureThe annealing temperature should be high enough for fasthomogenization interdiffusion and kinetics in the alloysMeanwhile the annealing temperature should be lower thanthe melting temperature of the alloys The lowest eutectictemperature in this system is around 390∘C in Zn-richcorner However this work is focused on Al-alloys and allsamples were prepared away from Zn-rich corner Therefore400∘C was selected in order to have faster interdiffusion andrelatively shorter annealing time

Key alloys and diffusion couples were investigated usingelectron probe microanalysis (EPMA) and scanning elec-tron microscopy (SEM) equipped with energy dispersiveX-ray spectroscopy (EDS) The microstructure and phasecomposition of the samples were analyzed either by EPMA(JOEL-JXA-8900) or SEMEDS (HITACHI S-3400N) Thedifference between EPMA and SEMEDS results was lessthan 2 at for Mn This value was obtained by comparingthe composition of several samples using both techniquesX-ray diffraction (XRD) was used for phase analysis of thekey alloys and for the determination of the solubility limitsof the compounds The XRD patterns were obtained usingPANanalytical Xpert Pro powder X-ray diffractometer [33]with a CuK120572 radiation at 45 kV and 40mA X-ray diffractionanalysis of the samples was carried out using XrsquoPert High-Score Plus Rietveld analysis software [33] Pearsonrsquos crystaldatabase [34] was used to identify the known phases in theAl-Mn-Zn system

3 Results and Discussion

31 Experimental Study of Diffusion Couples Isothermalsection of the Al-Mn-Zn ternary system was constructedbased on the experimental results of 5 diffusion couplesand 26 key samples shown in Figure 1 During the prelimi-nary study three ternary compounds 120591

1(Al31Mn8Zn11) 1205912

(Al71Mn16Zn13) and 120591

3(Al10Mn15Zn75) have been found

through diffusion couples analysisBackscattered electron image of DC 1 (Al-Mn

11Zn89) is

presented in Figure 2(a) Half of the image is colored forbetter representation of diffusion layers in this diffusion cou-ple The interdiffusion took place which led to the formationof several diffusion layers The compositions of the formedphases were determined using EPMA point analysis EPMAline-scan was used to determine the solubility ranges andphase equilibria among intermetallics Based on the compo-sition profile obtained by EPMA as shown in Figure 2(b)the diffusion path was depicted based on the sequence ofthe phases as Mn

5Zn21rarr Al

8Mn5rarr Al

11Mn4rarr

1205911rarr Al-fcc New ternary intermetallic compound 120591

1has

been found in this diffusion couple 1205911was determined as a

compound with the composition of Al62Mn16Zn22 As can

be seen from Figure 2(b) the three points of EPMA resultsshow no solubility range of 120591

1 Additional key alloy analysis

was consistent with the results of DC 1 (Al-Mn11Zn89)

This is why this compound is considered as stoichiometricFigure 2(c) shows the estimated diffusion path of DC 1 (Al-Mn11Zn89) plotted on the Al-Mn-Zn Gibbs triangle Layer

number 1 was determined asMn5Zn21 The solubility of Al in

Mn5Zn21

was measured as 5 at where Al atoms substituteZn atoms and Mn content remains constant at 16 at Basedon the local equilibrium at the Mn

5Zn21Al8Mn5interface

Mn5Zn21

is in equilibrium with Al8Mn5 In layer number

2 Al8Mn5solid solution dissolves up to 7 at Zn as shown

in Figure 2(b) This homogeneity range was also confirmedby DC 4 (Mn-Al

65Mn30Zn5) DC 5 (Al-Mn

32Zn68) and key

alloys 13ndash17The composition of Al8Mn5did not vary in DC 1

(Al-Mn11Zn89) because the diffusion path changed direction

to form Al11Mn4layer Layer number 3 was determined as

Al11Mn4with limited ternary solubility of around 2 at Zn

This value can be considered negligible because the estimatederror of EPMAmeasurement is about 2 at Layer number 4contains two phases these are Al

11Mn4and 1205911 The results of

point analysis indicated that Al11Mn4has negligible ternary

solubility and 1205911has the composition of Al

62Mn16Zn22 Layer

number 5 was identified as 1205911 Results of line-scan across

1205911layer showed that the composition of 120591

1is constant as

Al62Mn16Zn22 In layer number 6 Al-fcc was in equilibrium

with 1205911 The solubility of Zn in Al-fcc was found to reach up

to 20 at based on the EPMA line-scan resultsDC 2 (Mn-Al

94Zn6) was annealed at 400∘C for two

different time periods (15 and 25 days) in order to understandthe phase formation kinetics The annealing time resultedin significant growth of some compounds at the expense ofothersThis can be clearly seen in Figures 3(a) and 3(b) wherethe layer thickness of Al

11Mn4is growing at the expense of

Al4Mn and 120591

2 Six layers were observed in this diffusion cou-

ple for both annealing times The sequence of the observedphases is represented as follows Al-fcc rarr 120591

2rarr Al

4Mn rarr

Al11Mn4rarr Al

8Mn5rarr 120573-Mn1015840 rarr 120573-Mn10158401015840 rarr Mn The

ternary compound T3 (Al11Mn3Zn2) reported by [24] was

observed in this diffusion couple and is denoted as 1205912in this

paper as shown in Figures 3(a) and 3(b) 1205912was determined

as Al71Mn16Zn13 which is close to the composition of T3

(Al69Mn19Zn12) as reported byRaynor andWakeman [24] In

DC 2 (Mn-Al94Zn6) finger-like structuremorphology can be

observed after annealing for 15 days as shown in Figure 3(b)This type of morphology indicates anisotropic diffusion ofthe three elements in this system Al

11Mn4showed higher

growth rate compared to other phases in this diffusion coupleThis was concluded by comparing the micrographs of DC 2(Figures 3(a) and 3(b)) Both thicknesses of 120591

2and Al

4Mn

decreased after annealing for additional 10 days as shown inFigure 3(b) The Mn content of Al

4Mn was found to vary

from 18 at to 20 at after annealing for 15 days whereas itbecame constant at 20 atMnafter annealing for 25 daysThesolubility of Zn in Al

4Mn was measured as 5 at SEMEDS

analysis of DC 2 (Mn-Al94Zn6) annealed for 25 days is

presented in Figure 3(c) The solubility of Zn in Al8Mn5was

measured as 5 at The ternary solid solubility of 120573-Mn1015840 wasfound to be 4 at Zn 120573-Mn10158401015840 shows limited ternary solubilityof 3 at Al

4 Journal of Materials

Al-fcc

Line-scan

1 2 3 4 5 6

Al8Mn5 Al11Mn4 1205911Mn5Zn21 Al11Mn4 + 1205911

15120583m

(a)

0 2 4 6 8 10 12 14 16 18 20 22 240

102030405060708090

100

Al-fcc

Elem

ents

(at

)

Points number

ZnMnAl

Al8Mn5 Al11Mn4 1205911Mn5Zn21

(b)

4

6

5

3

2

Composition of detected phases

Mole fraction M

nMole

frac

tion

Al

Zn0 20 40 60 80 100

0

20

40

60

80

100 0

20

40

60

80

100

Mn

Al

Mole fraction Zn

DC 1

Diffusion path

1

6 Al-fcc layer

Al8Mn5

Al6MnAl4Mn

120573-Mn998400 120573-Mn998400998400

Al11Mn4

Al12MnMnZn13

MnZn9Mn5Zn21

120576

400∘C

1 Mn5Zn21 layer2 Al8Mn5 layer3 Al11Mn4 layer

4 Al11Mn4 + 1205911 layer5 1205911 layer

Al-f

cc

Liqu

idZn

-HCP

(c)

Figure 2 (a) Backscattered electron image of DC 1 (Al-Mn11

Zn89

) and its schematic (b) composition profile of the line-scan in DC 1 (Al-Mn11

Zn89

) (c) approximation of diffusion path of DC 1 (Al-Mn11

Zn89

)

Journal of Materials 5

Al8Mn5

Al4MnMn 120573-Mn998400

120573-Mn998400998400

Al11Mn4

Al-fcc1205912

(a)

Al8Mn5

Al4MnMn

120573-Mn998400

120573-Mn998400998400

Al11Mn4

Al-fcc

1205912

(b)

0 20 40 60 80 100

0

20

40

60

80

100 0

20

40

60

80

100

Composition of detected phases

Mole fraction M

nMole

frac

tion

Al

Zn

Mn

Al

Diffusion path

DC2

25 days

Mole fraction Zn

400∘C

Al8Mn5

Al6MnAl4Mn

120573-Mn998400 120573-Mn998400998400

Al12MnMnZn13

MnZn9Mn5Zn21

120576

1205912

Al11Mn4

Al-f

cc

Liqu

idZn

-HCP

(c)

Mole

frac

tion

Al

0 20 40 60 80 100

0

20

40

60

80

100 0

20

40

60

80

100

15 days25 days

Mole fraction M

n

Zn

Mn

Al

Mole fraction Zn

400∘C

Al8Mn5

Al6MnAl4Mn

120573-Mn998400 120573-Mn998400998400

Al11Mn4

Al12MnMnZn13

MnZn9Mn5Zn21

120576

1205912

Al-f

cc

Liqu

idZn

-HCP

(d)

Figure 3 (a) Backscattered electron image of DC 2 (Mn-Al94

Zn6

) annealed at 400∘C for 15 days along with its schematic (b) backscatteredelectron image of DC 2 (Mn-Al

94

Zn6

) annealed at 400∘C for 25 days along with its schematic (c) diffusion path of DC 2 (Mn-Al94

Zn6

)annealed for 25 days (d) comparisons of DC 2 (Mn-Al

94

Zn6

) annealed at 15 days and 25 days

Al-fcc

Al4Mn

50120583m

1205911

Figure 4 Backscattered electron image of sample 1

DC 3 (Al-Mn13Zn87) was studied using the same

approach as for DC 1 (Al-Mn11Zn89) and DC 2 (Mn-

Al94Zn6) Four phases have been identified through EPMA

analysis 1205913 Al8Mn5 Al11Mn4 and Al-fcc EPMA point

analysis indicated that the 1205913ternary compound had the

composition of Al10Mn15Zn75 Other than this the results of

this diffusion couple only confirmed the data obtained fromDC 1 and 2Therefore the details of DC 3 (Al-Mn

13Zn87) are

not mentioned here to avoid repetition

32 Experimental Study of Key Alloys Ten key alloys wereprepared to verify the formation of phases reported in theliterature and confirm the presence of the ternary compounds1205911 1205912 and 120591

3found in this experimental study The actual

6 Journal of Materials

Al-fcc

Al4Mn

Al6Mn

20120583m

(a)

Al-fcc

Al4Mn

Al6Mn

(b)

Figure 5 (a) Backscattered electron image of as-cast sample 7 (b) backscattered electron image of annealed sample 7

30 35 40 45 50 55 60 65 70 75 80 850

50

100

150

200

250

Al 148

Cou

nts

Position of 2120579

Al4Mn 562

Al6Mn 29

(a)

30 35 40 45 50 55 60 65 70 75 80 850

100

200

300

400

500

Cou

nts

Al 108

Position of 2120579

Al4Mn 14

Al6Mn 752

(b)

Figure 6 (a) XRD spectrum of as-cast sample 7 (b) XRD spectrum of annealed sample 7

Al4Mn Al-fcc

1205912

Figure 7 Backscattered electron image of sample 3

composition of these key alloys and the composition of thedetected phases are presented in Table 2

The ternary compounds T1 (Al24Mn5Zn) and T2

(Al9Mn2Zn) [24] were not observed in this system at 400∘C

As shown in Table 2 key alloy 7 was prepared close tothe composition of T1 compound key alloys 5 and 6 weremade close to the composition of T2 compound HoweverT1 and T2 were not detected It should be mentioned thatRaynor and Wakeman [24] used only as-cast samples intheir study and reported compounds could be metastable orhigh temperature phases Furthermore they [24] have usedthe wet chemical analysis of small quantities of extractedcrystals which may cause errors in phase compositionsdetermination compared to EPMA point analysis usedin our work The existence of 120591

1phase was confirmed in

sample 1 as a stoichiometric compound with Al64Mn15Zn21

composition The microstructure of this alloy is shown inFigure 4 120591

1formed during a peritectic reaction which is hard

to be terminated during short annealing period Thereforethe primary phase Al

4Mn was not decomposed completely

even after annealing for 30 days Similar phenomenon wasalso observed in key sample 7 Figures 5(a) and 5(b) showthe as-cast and annealed microstructures of sample 7 It isclear that Al

4Mn (the white phase) formed as a primary

phase Al6Mn then formed according to the peritectic

reaction L + Al4Mn rarr Al

6Mn After annealing for 30 days

Journal of Materials 7

Table 2 The actual compositions of the key samples and the detected phases

Samplenumber

Actual compositionidentified by ICP (at) Phase identification

Composition ofidentified phasesby EPMA (at)

Al Mn Zn ByEPMA

ByXRD Al Mn Zn

1 44 16 40Al4Mn Al4Mn 74 20 61205911

64 15 21Al-fcc Al-fcc 55 0 45

2 75 13 121205912

1205912

73 15 12Al4Mn Al4Mn 74 20 6Al-fcc Al-fcc 78 0 22

3 78 15 71205912

1205912

75 14 11Al4Mn Al4Mn 75 20 5Al-fcc Al-fcc 88 0 12

4 79 10 111205912

1205912

72 16 12Al4Mn Al4Mn 76 20 4Al-fcc Al-fcc 79 0 21

5 74 16 101205912

1205912

73 15 12Al4Mn Al4Mn 74 20 6Al-fcc Al-fcc 75 0 25

6 74 15 111205912

1205912

72 15 13Al4Mn Al4Mn 74 20 6Al-fcc Al-fcc 80 0 20

7 84 12 4Al6Mn Al6Mn 86 14 0Al4Mn Al4Mn 75 20 5Al-fcc Al-fcc 95 0 5

8 82 11 7Al12Mn 92 8 0Al6Mn 83 15 2Al-fcc 96 0 4

9 21 14 651205913

12 11 77Al11Mn4 Al11Mn4 70 26 3Al8Mn5 Al8Mn5 56 37 7

10 16 14 701205913

12 11 771205914

23 16 61Al11Mn4 Al11Mn4 71 25 4

11 23 16 61

1205913

13 13 741205914

25 18 57Al11Mn4 Al11Mn4 69 27 4Al8Mn5 Al8Mn5 55 36 9

12 17 15 68Al11Mn4 Al11Mn4 70 26 41205913

13 11 761205914

23 16 61

13 18 22 60 1205913

10 15 75Al8Mn5 Al8Mn5 52ndash57 33ndash37 10ndash11

14 64 31 5 Al11Mn4 Al11Mn4 70 26 4Al8Mn5 Al8Mn5 55 34 10

15 56 37 7 Al8Mn5 Al8Mn5 57 39 4

16 55 35 10 Al11Mn4 Al11Mn4 70 27 3Al8Mn5 Al8Mn5 57 34 9

17 30 35 35 Al8Mn5 54 38 8120576 74 22 4

8 Journal of Materials

(a)

Al8Mn5

Al11Mn4

1205913

(b)

Al11Mn4

1205913

1205914

10120583m

(c)

Al11Mn4

1205913

100120583m

(d)

Figure 8 (a) Backscattered electron image of annealed sample 9 at 400∘C for 30 days (b) magnified area of sample 9 (c) backscatteredelectron image of sample 10 annealed at 400∘C for 25 days (d) backscattered electron image of sample 10 annealed at 400∘C for 40 days

30 35 40 45 50 55 60 65 70 75 800

50100150200250300350400450500550600650700

Al

Cou

nts

Position of 2120579

Al4Mn1205911

Figure 9 XRD spectrum of annealed sample 1

the amount of Al4Mn decreased and decomposed to Al

6Mn

The microstructure of annealed sample 7 is shown inFigure 5(b) Using XRD analysis the weight fraction ofAl4Mn and Al

6Mn in the as-cast sample was measured

as 562 and 29 respectively as shown in Figure 6(a)

The amount of Al4Mn and Al

6Mn changed dramatically

after annealing for 30 days to become 14 and 822as demonstrated in Figure 6(b) This variation indicatesperitectic decomposition upon annealing Due to the naturalsluggish kinetics of peritectic reaction the transformation ofAl4Mn to Al

6Mn requires very long time

The formation of 1205912was confirmed after analysis of key

alloys 2 to 6 The microstructure of sample 3 is shown inFigure 7 EPMA results indicated that 120591

2is a stoichiometric

compound with Al71Mn16Zn13

composition It has beenobserved that the Mn content of Al

4Mn varies in the range of

18ndash21 at which could be owing to the Zn substitution Thedissolved Zn in Al

4Mn was found to reach up to 6 at Sub-

stitution of third element could lead to the small variationsof compositions On the other hand these Mn content devia-tions could be due to the fact that Al

4Mn forms quasicrystals

The structure of quasicrystal may change under differentsolidification conditions [27] Schaefer et al [27] mentionedthat Al

4Mn formed icosahedral or decagonal quasicrystals

and structural changes in solid solutions could affect the com-positions They [27] observed that composition of ternaryquasicrystals most likely fall in the range of 18ndash22 at Mnwhich was close to the composition region of the stable 120583-Al4Mn phase The composition of reported T1 is close to

Journal of Materials 9

30 35 40 45 50 55 60 65 70 75 800

50

100

150

200

250

300

350C

ount

s

Position of 2120579

(a)

30 35 40 45 50 55 60 65 70 75 800

50

100

150

200

250

300

350

Cou

nts

Position of 2120579

(b)

30 35 40 45 50 55 60 65 70 75 800

50

100

150

200

250

300

Cou

nts

SiAl

Position of 2120579

Al4Mn1205912

(c)

Figure 10 (a) XRD spectrum of annealed sample 2 (b) XRD spectrum of annealed sample 3 (c) XRD spectrum of annealed sample 5

the homogeneity range of Al4Mn which indicated that T1

might be a quasicrystal of Al4Mnwith extended Zn solubility

1205913was observed in DC 3 (Al-Mn

13Zn87) and the com-

position was primarily determined as Al10Mn15Zn75 Several

key alloys were prepared to study this new compound Theactual compositions of these samples and the compositionsof the detected phases are listed in Table 2 The 120591

3phase has

a complex homogeneity range 9ndash13 at Al 11ndash15 at Mnand 75ndash77 at Zn as was determined by the analysis of DC3 (Al-Mn

13Zn87) and key samples 9 to 13 Sample 9 is an

example of these findings as shown in Figures 8(a) and 8(b)The sample contains residuals of the primary Al

8Mn5phase

that decomposes according to the peritectic reaction L+Al8Mn5rarr Al

11Mn4 The decomposition of Al

8Mn5was not

complete due to the slow kinetics of the peritectic reaction 1205913

phase formed a matrix in this alloyThe homogeneity ranges of the binary compounds were

determined using EPMA From the EPMA results Al11Mn4

exhibited ternary solubility reaching up to 4 at Zn Al4Mn

had the maximum ternary solubility of 6 at Zn Thedissolved Zn in Al-fcc was found to reach up to 45 atTernary homogeneity range of Al

8Mn5has been determined

by EPMA as 11 atZnThese observations also confirmed theresults which were inferred from DC 4 (Mn-Al

65Mn30Zn5)

Additionally another ternary phase 1205914was found in this

ternary system The composition of this phase is in the

region around Al23Mn16Zn61 However 120591

4is found to be

metastable As shown in Figure 8(c) three phases Al11Mn4

1205913 and 120591

4were found in sample 12 to be annealed at 400∘C

for 25 days After prolonged annealing for another 15 days 1205914

decomposed to provide more 1205913and Al

11Mn4

In order to verify the observations of the ternary com-pounds key alloys were studied using XRD The XRDpatterns of sample 1 are illustrated in Figure 9 Al-fcc andAl4Mn are positively identified in the XRD pattern Besides

there are several peaks which do not belong to any of theknown binary phases in the system Based on the resultsof phase identifications those peaks could correspond to1205911 Because of the lack of the reported prototype of 120591

1 the

peaks which belong to 1205911were hard to separate due to the

several overlapping peaks in the XRD pattern of this sampleThus the crystal structure of this compound could not bedetermined in the current study However the peaks whichcould belong to 120591

1have been labeled as shown in Figure 9

T3 phase reported by [24] denoted as 1205912in the current

study was confirmed through XRD analysis Three XRDspectra of sample 2 3 and 5 were used for this purpose Asshown in Figure 10 the XRD patterns of the three samplesare similar From 2120579 position 40∘ to 45∘ hump-like patternscan be observed due to peaks overlapping This is becauseAl4Mnhas very complex crystal structure and has around 550

atoms in a giant unit cell [34] During the X-ray scanning

10 Journal of Materials

Mn

Al8Mn5Al8Mn5

120573-Mn998400

Al11Mn4

50120583m

(a)

0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 340

10

20

30

40

50

60

70

80

90

100

Elem

ents

(at

)

Points number

MnZn

AlAl8Mn5

Al8Mn5120573-Mn998400

Al11Mn4

Al8Mn5

Al11Mn4

(b)

Figure 11 (a) Backscattered electron image of diffusion couple DC 4 (Mn-Al65

Mn30

Zn5

) (b) composition profile of line-scan in diffusioncouple DC 4 (Mn-Al

65

Mn30

Zn5

)

process the diffracted spectra of Al4Mn were overlapping

with other peaks at numerous positions and generate theseoverlapped patterns Using the crystallographic entry of T3from Pearsonrsquos database [34] T3 was positively identifiedamong XRD analysis Along with Al-fcc and Al

4Mn the

triangulation among those three phases was establishedXRD analysis of ternary compound 120591

3has similar issues

to 1205911as elucidated above Unfortunately too many peaks

were overlapping in a multiphase alloy and a single-phasesample representing 120591

3was not possible to prepareTherefore

the crystal structure of this compound has not been deter-mined either

33 Description of Ternary Solid Solutions

331 Homogeneity Range of Al8Mn5and Al

11Mn4 Al8Mn5

has wide homogeneity range in Al-Mn binary system How-ever it is difficult to estimate how much of Zn dissolvedin this compound from the results of DC 2 (Mn-Al

94Zn6)

Journal of Materials 11

Al8Mn5

Al11Mn4

80120583m

(a)

Al8Mn5

50120583m

(b)

20 25 30 35 40 45 50 550

100

200

300

400

500

600

Cou

nts

Position of 2120579

Al8Mn5

98 Al8Mn5

(c)

Figure 12 (a) Backscattered electron image of sample 14 (b) backscattered electron image of sample 15 (c) XRD spectrum of sample 15

Thus DC 4 (Mn-Al65Mn30Zn5) was prepared in order to

determine the homogeneity range of Al8Mn5in this ternary

system Because Al11Mn4has higher growth rate one end

member of DC 4 (Mn-Al65Mn30Zn5) has been selected near

the Al8Mn5region to increase the atomic exchange between

Al and Mn From the backscattered electron image of DC4 (Mn-Al

65Mn30Zn5) shown in Figure 11(a) Al

8Mn5formed

a thick layer and the color changed along with decreasingMn content which suggests the presence of a homogeneityrange Line-scan shown in Figure 11(b) was carried outto determine the homogeneity range of Al

8Mn5 In the

Al11Mn4+ Al8Mn5two-phase region dotted lines denote

the concentrations of elements in Al11Mn4and solid lines

represent the concentrations of elements in Al8Mn5 The

SEMEDS analysis showed that Al8Mn5has ternary solubility

of 9 at Zn and Al11Mn4has maximum ternary solubility

of 4 at Zn Al concentration in Al8Mn5layer varied from

49 at to 58 atAl11Mn4and Al

8Mn5showed extended ternary solubility

in this system at 400∘C In order to confirm the resultsobtained from previous diffusion couples four key alloys(14 to 17) were prepared The composition and phase iden-tification of these key samples are summarized in Table 2The phase relations obtained from EPMA showed greatconsistency with the XRD results Backscattered electronimage of sample 14 is shown in Figure 12(a) From EPMA

point analysis Al11Mn4has a ternary solubility of about 4 at

Zn and Al8Mn5has a maximum ternary solubility of 10 at

Zn These results were consistent with the previous EPMAobservation of samples 9 and 11 Figure 12(b) shows thatsample 15 contains mainly Al

8Mn5whose ternary solubility

was measured around 4 at Zn The XRD analysis also con-firmed that Al

8Mn5is dominating in sample 15 as shown in

Figure 12(c)There are a few unlabeled small peaks indicatingthe presence of Al

11Mn4traces which could not be identified

in the current study because of their low intensity

332 Single Region of 120576 Phase Controversy on whether120576 has three-phase separations reported in the assessmentof Okamoto and Tanner [15] is still not resolved In thecurrent study one end-member of DC 5 (Al-Mn

32Zn68)

has a composition in the 120576-phase region EPMA line-scanindicated that 120576-phase has continuous binary solubility rangesreaching fromMn

32Zn68to Mn

40Zn60at 400∘CThis finding

also corresponds to the Mn-Zn binary system which wasreported by [32 35] The backscattered electron image of DC5 (Al-Mn

32Zn68) is presented in Figure 13 Five phases have

been identified 120576 Al-rich 120573-Mn1015840 Al8Mn5 Al11Mn4 and Al-

fcc In the current experimental investigation the maximumsolubility of Zn in 120573-Mn1015840 was measured as 4 at Single 120576-phase region with the Mn content from 32 to 40 at was

12 Journal of Materials

Al8Mn5

120573-Mn998400

Al11Mn4

Al-fcc

Mn32Zn68(120576)

Figure 13 Backscattered electron image of DC 5 (Al-Mn32

Zn68

)

observed at 400∘C and nothing indicated the presence ofphase separation in this composition range From the resultsof sample 17 (Al

30Mn35Zn35) 120576-phase was found to have

limited ternary solubility of 4 at Al

34 Isothermal Section of Al-Mn-Zn System at 400∘C Com-bining the results which were obtained from the diffusioncouples with those obtained from the key alloys the Al-Mn-Zn isothermal section at 400∘C was constructed and pre-sented in Figure 14 Solid lines represent the experimentallyverified phase boundaries and ternary solubility of binaryphases Dotted lines are the estimated phase relationshipswhich were not confirmed in the current study They wereconstructed based on the Gibbs phase rule [36] and Schreine-makerrsquos rule [37] Grey blue and green areas indicate thesingle two-phase and three-phase regions separately asshown in Figure 14

4 Conclusion

The Al-Mn-Zn isothermal section at 400∘C was constructedbased on the current experimental results of diffusion coupletechnique and selected key alloys Phase relationships andsolubility limits have been determined for the ternary andbinary compounds The previously reported ternary com-pound T3 was confirmed in the current study and is denotedas 1205912in this paper Two new ternary compounds 120591

1and 1205913

have been found in this system at 400∘C 1205911does not show

significant solubility ranges and is considered stoichiometric1205913is a solid solution with a narrow homogeneity range

The formulae of the three Al-Mn-Zn ternary intermetalliccompounds are 120591

1 Al31Mn8Zn11 1205912 Al72Mn16Zn12 and 120591

3

Al119909Mn119910Zn119911(119909 = 9ndash13 at 119910 = 11ndash15 at 119911 = 75ndash77 at) A

single-phase region of Al8Mn5with extended solubility was

found in this system at 400∘C Based on the current findingsthe ternary solubilities of the Al

8Mn5 Al4Mn and Al

11Mn4

compounds have been determined as 10 at 6 at and 4 atZn respectively 120576 and Mn

5Zn21

exhibit their maximumsolubilities of 4 at and 5 at Al The solubility of Zn in120573-Mn1015840 has been found to be 4 at and 120573-Mn10158401015840 has ternarysolubility of 3 at Al

Mole

frac

tion

Al

0 20 40 60 80 100

0

20

40

60

80

100 0

20

40

60

80

100

Single-phase regionTwo-phase region

Mole fraction M

n

Zn

Mn

AlMole fraction Zn

400∘C

Al8Mn5

Al 8Mn 5

Al6MnAl4Mn

120573-Mn998400 120573-M

n998400

120573-Mn998400998400

Al11Mn4

Al12Mn MnZn13MnZn9

Mn5Zn21

120576

Three-phase region

1205912 1205911

Al-f

cc

Liqu

idZn

-HCP

120573-Mn998400 + 120573-Mn998400998400

120573-Mn 998400+ 120573-Mn 998400998400

+ 120576

Al8Mn5 + 120573- Mn998400

Al8Mn5 + 120576Al8Mn

5 + Mn5Zn

21 + 1205913

Al8Mn5 + Al11Mn4 + 12059131205911 + Al11Mn4 + 1205913

1205911 + Al-fcc + 1205913

Al8Mn5 + 120573-Mn 998400

+ 120576

Figure 14 Isothermal section of Al-Mn-Zn ternary system at 400∘Cconstructed by diffusion couples and key samples

Conflict of Interests

The authors declare that there is no conflict of interestsof any sort that might have influenced the discussions orconclusions of this paper

Acknowledgments

Financial support from General Motors of Canada Ltd andthe Natural Sciences and Engineering Research Councilof Canada (NSERC) through the CRD grant program isgratefully acknowledged The authors would also like toacknowledge the help of Mohammad Mezbahul-Islam ofMechanical Engineering Department Concordia Universityfor his valuable suggestions

References

[1] G S Cole and A M Sherman ldquoLight weight materials forautomotive applicationsrdquo Materials Characterization vol 35no 1 pp 3ndash9 1995

[2] S W Nam and B O Kong ldquoDevelopment of weldable highstrength alalloyrdquo KOSEF Technical Report 1993

[3] H S Cho and S W Nam ldquoA study of the low cycle fatigueproperties of weldable Al-Zn-Mg-Mn Alloy and Al 7039 invarious environmentsrdquo Journal of Korean Institute of Metals andMaterials vol 32 no 7 pp 765ndash770 1994

[4] M Ohno D Mirkovic and R Schmid-Fetzer ldquoLiquidus andsolidus temperatures of Mg-rich Mg-Al-Mn-Zn alloysrdquo ActaMaterialia vol 54 no 15 pp 3883ndash3891 2006

[5] N Gao Y H Liu and N-Y Tang ldquoAn experimental study ofthe liquid domain of the Zn-Fe-Al-Mn quaternary system at

Journal of Materials 13

460∘Crdquo Journal of Phase Equilibria and Diffusion vol 31 no 6pp 523ndash531 2010

[6] M A Khan and M Medraj ldquoThermodynamic descriptionof the Mg-Mn Al-Mn and Mg-Al-Mn systems using themodified quasichemical model for the liquid phasesrdquoMaterialsTransactions vol 50 no 5 pp 1113ndash1122 2009

[7] C Muller H Stadelmaier B Reinsch and G Petzow ldquoMet-allurgy of the magnetic 120591-phase in Mn-Al and Mn-Al-CrdquoZeitschrift fuer Metallkunde vol 87 no 7 pp 594ndash597 1996

[8] A Shukla and A D Pelton ldquoThermodynamic assessment of theAl-Mn andMg-Al-Mn systemsrdquo Journal of Phase Equilibria andDiffusion vol 30 no 1 pp 28ndash39 2009

[9] H Kono ldquoOn the ferromagnetic phase in manganese-aluminum systemrdquo Journal of the Physical Society of Japan vol13 no 12 pp 1444ndash1451 1958

[10] W Koster and E Wachtel ldquoConstitution and magnetic proper-ties of aluminum-manganese alloyswithmore than 5AtMnrdquoZeitschrift fuer Metallkunde vol 51 pp 271ndash280 1960

[11] Y Minamino T Yamane H Araki et al ldquoSolid solubilities ofmanganese and titanium in aluminum at 01 MPa and 21 GPardquoMetallurgical Transactions A vol 22 no 3 pp 783ndash786 1991

[12] H Okamoto ldquoAl-Mn (Aluminum-Manganese)rdquo Journal ofPhase Equilibria vol 18 no 4 pp 398ndash399 1997

[13] M A Taylor ldquoIntermetallig phases in the aluminiumman-ganese binary systemrdquo Acta Metallurgica vol 8 no 4 pp 256ndash262 1960

[14] S Wasiur-Rahman andMMedraj ldquoA thermodynamic descrip-tion of the Al-Ca-Zn ternary systemrdquoCalphad vol 33 no 3 pp584ndash598 2009

[15] H Okamoto and L E Tanner ldquoThe Mn-Zn (Manganese-Zinc)systemrdquo Bulletin of Alloy Phase Diagrams vol 11 no 4 pp 377ndash384 1990

[16] S Tezuka S Sakai and Y Nakagawa ldquoFerromagnetism of Mn-Zn alloyrdquo Journal of the Physical Society of Japan vol 15 no 5p 931 1960

[17] Y Nakagawa and T Hori ldquoMagnetic transition and crystaldistortion in MnHg andMnZn

3

rdquo Journal of the Physical Societyof Japan vol 17 no 8 pp 1313ndash1314 1962

[18] B Henderson and R J M Willcox ldquoLattice spacing relation-ships in hexagonal close-packed Silver-Zinc-Manganese alloysrdquoPhilosophical Magazine vol 9 no 101 pp 829ndash846 1964

[19] R A Farrar and H W King ldquoAxial ratios and solubility limitsof HCP 120578 and 120576 phases in the systems CdMn and ZnMnrdquoMetallography vol 3 no 1 pp 61ndash70 1970

[20] J L Liang Y Du C Z Liao et al ldquoExperimental investigationon the phase equilibria of the Mn-Ni-Zn system at 400∘CrdquoJournal of Alloys and Compounds vol 489 no 2 pp 362ndash3682010

[21] J L Liang Y Du Q Z Zhao et al ldquoDetermination of the phaseequilibria in the Mn-Sn-Zn system at 500∘ Crdquo MetallurgicalandMaterials Transactions A PhysicalMetallurgy andMaterialsScience vol 40 no 12 pp 2909ndash2918 2009

[22] H Xu X Xiong L Zhang YDu and PWang ldquoPhase equilibriaof the Mn-Si-Zn system at 600∘Crdquo Metallurgical and MaterialsTransactions A Physical Metallurgy and Materials Science vol40 no 9 pp 2042ndash2047 2009

[23] E Gebhardt ldquoDie zinkecke des dreistoffsystems zink-aluminium-manganrdquo Zeitschrift fur Metallkunde vol 34pp 259ndash263 1942

[24] G V Raynor and D W Wakeman ldquoThe intermetallic com-pound phases of the system Aluminium-Manganese-Zincrdquo

Proceedings of the Royal Society of London A Mathematical andPhysical Sciences vol 190 no 1020 pp 82ndash101 1947

[25] K Robinson ldquoThe determination of the crystal structure ofNi4

Mn11

Al60

rdquo Acta Crystallographica vol 7 part 6-7 pp 494ndash497 1954

[26] A Damjanovic ldquoThe structure analysis of the T3

(A1MnZn)compoundrdquo Acta Crystallographica vol 14 pp 982ndash987 1961

[27] R J Schaefer L A Bendersky D Shechtman W J Boettingerand F S Biancaniello ldquoIcosahedral and decagonal phase forma-tion in Al-Mn Alloysrdquo Metallurgical transactions A vol 17 no12 pp 2117ndash2125 1986

[28] A Singh S Ranganathan and L A Bendersky ldquoQuasicrys-talline phases and their approximants inAl-Mn-Zn alloysrdquoActaMaterialia vol 45 no 12 pp 5327ndash5336 1997

[29] J S Kirkaldy and L C Brown ldquoDiffusion behavior in theternarymultiphase systemsrdquoCanadianMetallurgicalQuarterlyvol 2 no 1 pp 90ndash115 1963

[30] J B Clark ldquoConventions for plotting the diffusion paths inmultiphase ternary diffusion couples on the isothermal sectionof a ternary phase diagramrdquo Transactions of the MetallurgicalSociety of AIME vol 227 pp 1250ndash1251 1963

[31] A A Kodentsov G F Bastin and F J J van Loo ldquoThe diffusioncouple technique in phase diagram determinationrdquo Journal ofAlloys and Compounds vol 320 no 2 pp 207ndash217 2001

[32] M A Khan Thermodynamic modeling of the MgndashMnndash(Al Zn)systems [MS thesis] Concordia University 2009

[33] PANalytical Ver22b (222) PANalytical Almelo The Nether-lands 2006

[34] H Putz and K Brandenburg Pearsonrsquos Crystal Data CrystalStructure Database for Inorganic Compounds CD-ROM Soft-ware Version 13

[35] P Ghosh and M Medraj ldquoThermodynamic calculation of theMg-Mn-Zn and Mg-Mn-Ce systems and re-optimization oftheir constitutive binariesrdquo Calphad Computer Coupling ofPhase Diagrams andThermochemistry vol 41 pp 89ndash107 2013

[36] A Prince Alloy Phase Equilibria Elsevier Amsterdam TheNetherland 1966

[37] L Y H John ldquoSchreinemakers rule as applied to non-degenerate ternary systemsrdquoThe Journal of Young Investigatorsvol 19 no 11 2009

Submit your manuscripts athttpwwwhindawicom

ScientificaHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CorrosionInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Polymer ScienceInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CeramicsJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CompositesJournal of

NanoparticlesJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

International Journal of

Biomaterials

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

NanoscienceJournal of

TextilesHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Journal of

NanotechnologyHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

CrystallographyJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CoatingsJournal of

Advances in

Materials Science and EngineeringHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Smart Materials Research

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

MetallurgyJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

BioMed Research International

MaterialsJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Nano

materials

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal ofNanomaterials

4 Journal of Materials

Al-fcc

Line-scan

1 2 3 4 5 6

Al8Mn5 Al11Mn4 1205911Mn5Zn21 Al11Mn4 + 1205911

15120583m

(a)

0 2 4 6 8 10 12 14 16 18 20 22 240

102030405060708090

100

Al-fcc

Elem

ents

(at

)

Points number

ZnMnAl

Al8Mn5 Al11Mn4 1205911Mn5Zn21

(b)

4

6

5

3

2

Composition of detected phases

Mole fraction M

nMole

frac

tion

Al

Zn0 20 40 60 80 100

0

20

40

60

80

100 0

20

40

60

80

100

Mn

Al

Mole fraction Zn

DC 1

Diffusion path

1

6 Al-fcc layer

Al8Mn5

Al6MnAl4Mn

120573-Mn998400 120573-Mn998400998400

Al11Mn4

Al12MnMnZn13

MnZn9Mn5Zn21

120576

400∘C

1 Mn5Zn21 layer2 Al8Mn5 layer3 Al11Mn4 layer

4 Al11Mn4 + 1205911 layer5 1205911 layer

Al-f

cc

Liqu

idZn

-HCP

(c)

Figure 2 (a) Backscattered electron image of DC 1 (Al-Mn11

Zn89

) and its schematic (b) composition profile of the line-scan in DC 1 (Al-Mn11

Zn89

) (c) approximation of diffusion path of DC 1 (Al-Mn11

Zn89

)

Journal of Materials 5

Al8Mn5

Al4MnMn 120573-Mn998400

120573-Mn998400998400

Al11Mn4

Al-fcc1205912

(a)

Al8Mn5

Al4MnMn

120573-Mn998400

120573-Mn998400998400

Al11Mn4

Al-fcc

1205912

(b)

0 20 40 60 80 100

0

20

40

60

80

100 0

20

40

60

80

100

Composition of detected phases

Mole fraction M

nMole

frac

tion

Al

Zn

Mn

Al

Diffusion path

DC2

25 days

Mole fraction Zn

400∘C

Al8Mn5

Al6MnAl4Mn

120573-Mn998400 120573-Mn998400998400

Al12MnMnZn13

MnZn9Mn5Zn21

120576

1205912

Al11Mn4

Al-f

cc

Liqu

idZn

-HCP

(c)

Mole

frac

tion

Al

0 20 40 60 80 100

0

20

40

60

80

100 0

20

40

60

80

100

15 days25 days

Mole fraction M

n

Zn

Mn

Al

Mole fraction Zn

400∘C

Al8Mn5

Al6MnAl4Mn

120573-Mn998400 120573-Mn998400998400

Al11Mn4

Al12MnMnZn13

MnZn9Mn5Zn21

120576

1205912

Al-f

cc

Liqu

idZn

-HCP

(d)

Figure 3 (a) Backscattered electron image of DC 2 (Mn-Al94

Zn6

) annealed at 400∘C for 15 days along with its schematic (b) backscatteredelectron image of DC 2 (Mn-Al

94

Zn6

) annealed at 400∘C for 25 days along with its schematic (c) diffusion path of DC 2 (Mn-Al94

Zn6

)annealed for 25 days (d) comparisons of DC 2 (Mn-Al

94

Zn6

) annealed at 15 days and 25 days

Al-fcc

Al4Mn

50120583m

1205911

Figure 4 Backscattered electron image of sample 1

DC 3 (Al-Mn13Zn87) was studied using the same

approach as for DC 1 (Al-Mn11Zn89) and DC 2 (Mn-

Al94Zn6) Four phases have been identified through EPMA

analysis 1205913 Al8Mn5 Al11Mn4 and Al-fcc EPMA point

analysis indicated that the 1205913ternary compound had the

composition of Al10Mn15Zn75 Other than this the results of

this diffusion couple only confirmed the data obtained fromDC 1 and 2Therefore the details of DC 3 (Al-Mn

13Zn87) are

not mentioned here to avoid repetition

32 Experimental Study of Key Alloys Ten key alloys wereprepared to verify the formation of phases reported in theliterature and confirm the presence of the ternary compounds1205911 1205912 and 120591

3found in this experimental study The actual

6 Journal of Materials

Al-fcc

Al4Mn

Al6Mn

20120583m

(a)

Al-fcc

Al4Mn

Al6Mn

(b)

Figure 5 (a) Backscattered electron image of as-cast sample 7 (b) backscattered electron image of annealed sample 7

30 35 40 45 50 55 60 65 70 75 80 850

50

100

150

200

250

Al 148

Cou

nts

Position of 2120579

Al4Mn 562

Al6Mn 29

(a)

30 35 40 45 50 55 60 65 70 75 80 850

100

200

300

400

500

Cou

nts

Al 108

Position of 2120579

Al4Mn 14

Al6Mn 752

(b)

Figure 6 (a) XRD spectrum of as-cast sample 7 (b) XRD spectrum of annealed sample 7

Al4Mn Al-fcc

1205912

Figure 7 Backscattered electron image of sample 3

composition of these key alloys and the composition of thedetected phases are presented in Table 2

The ternary compounds T1 (Al24Mn5Zn) and T2

(Al9Mn2Zn) [24] were not observed in this system at 400∘C

As shown in Table 2 key alloy 7 was prepared close tothe composition of T1 compound key alloys 5 and 6 weremade close to the composition of T2 compound HoweverT1 and T2 were not detected It should be mentioned thatRaynor and Wakeman [24] used only as-cast samples intheir study and reported compounds could be metastable orhigh temperature phases Furthermore they [24] have usedthe wet chemical analysis of small quantities of extractedcrystals which may cause errors in phase compositionsdetermination compared to EPMA point analysis usedin our work The existence of 120591

1phase was confirmed in

sample 1 as a stoichiometric compound with Al64Mn15Zn21

composition The microstructure of this alloy is shown inFigure 4 120591

1formed during a peritectic reaction which is hard

to be terminated during short annealing period Thereforethe primary phase Al

4Mn was not decomposed completely

even after annealing for 30 days Similar phenomenon wasalso observed in key sample 7 Figures 5(a) and 5(b) showthe as-cast and annealed microstructures of sample 7 It isclear that Al

4Mn (the white phase) formed as a primary

phase Al6Mn then formed according to the peritectic

reaction L + Al4Mn rarr Al

6Mn After annealing for 30 days

Journal of Materials 7

Table 2 The actual compositions of the key samples and the detected phases

Samplenumber

Actual compositionidentified by ICP (at) Phase identification

Composition ofidentified phasesby EPMA (at)

Al Mn Zn ByEPMA

ByXRD Al Mn Zn

1 44 16 40Al4Mn Al4Mn 74 20 61205911

64 15 21Al-fcc Al-fcc 55 0 45

2 75 13 121205912

1205912

73 15 12Al4Mn Al4Mn 74 20 6Al-fcc Al-fcc 78 0 22

3 78 15 71205912

1205912

75 14 11Al4Mn Al4Mn 75 20 5Al-fcc Al-fcc 88 0 12

4 79 10 111205912

1205912

72 16 12Al4Mn Al4Mn 76 20 4Al-fcc Al-fcc 79 0 21

5 74 16 101205912

1205912

73 15 12Al4Mn Al4Mn 74 20 6Al-fcc Al-fcc 75 0 25

6 74 15 111205912

1205912

72 15 13Al4Mn Al4Mn 74 20 6Al-fcc Al-fcc 80 0 20

7 84 12 4Al6Mn Al6Mn 86 14 0Al4Mn Al4Mn 75 20 5Al-fcc Al-fcc 95 0 5

8 82 11 7Al12Mn 92 8 0Al6Mn 83 15 2Al-fcc 96 0 4

9 21 14 651205913

12 11 77Al11Mn4 Al11Mn4 70 26 3Al8Mn5 Al8Mn5 56 37 7

10 16 14 701205913

12 11 771205914

23 16 61Al11Mn4 Al11Mn4 71 25 4

11 23 16 61

1205913

13 13 741205914

25 18 57Al11Mn4 Al11Mn4 69 27 4Al8Mn5 Al8Mn5 55 36 9

12 17 15 68Al11Mn4 Al11Mn4 70 26 41205913

13 11 761205914

23 16 61

13 18 22 60 1205913

10 15 75Al8Mn5 Al8Mn5 52ndash57 33ndash37 10ndash11

14 64 31 5 Al11Mn4 Al11Mn4 70 26 4Al8Mn5 Al8Mn5 55 34 10

15 56 37 7 Al8Mn5 Al8Mn5 57 39 4

16 55 35 10 Al11Mn4 Al11Mn4 70 27 3Al8Mn5 Al8Mn5 57 34 9

17 30 35 35 Al8Mn5 54 38 8120576 74 22 4

8 Journal of Materials

(a)

Al8Mn5

Al11Mn4

1205913

(b)

Al11Mn4

1205913

1205914

10120583m

(c)

Al11Mn4

1205913

100120583m

(d)

Figure 8 (a) Backscattered electron image of annealed sample 9 at 400∘C for 30 days (b) magnified area of sample 9 (c) backscatteredelectron image of sample 10 annealed at 400∘C for 25 days (d) backscattered electron image of sample 10 annealed at 400∘C for 40 days

30 35 40 45 50 55 60 65 70 75 800

50100150200250300350400450500550600650700

Al

Cou

nts

Position of 2120579

Al4Mn1205911

Figure 9 XRD spectrum of annealed sample 1

the amount of Al4Mn decreased and decomposed to Al

6Mn

The microstructure of annealed sample 7 is shown inFigure 5(b) Using XRD analysis the weight fraction ofAl4Mn and Al

6Mn in the as-cast sample was measured

as 562 and 29 respectively as shown in Figure 6(a)

The amount of Al4Mn and Al

6Mn changed dramatically

after annealing for 30 days to become 14 and 822as demonstrated in Figure 6(b) This variation indicatesperitectic decomposition upon annealing Due to the naturalsluggish kinetics of peritectic reaction the transformation ofAl4Mn to Al

6Mn requires very long time

The formation of 1205912was confirmed after analysis of key

alloys 2 to 6 The microstructure of sample 3 is shown inFigure 7 EPMA results indicated that 120591

2is a stoichiometric

compound with Al71Mn16Zn13

composition It has beenobserved that the Mn content of Al

4Mn varies in the range of

18ndash21 at which could be owing to the Zn substitution Thedissolved Zn in Al

4Mn was found to reach up to 6 at Sub-

stitution of third element could lead to the small variationsof compositions On the other hand these Mn content devia-tions could be due to the fact that Al

4Mn forms quasicrystals

The structure of quasicrystal may change under differentsolidification conditions [27] Schaefer et al [27] mentionedthat Al

4Mn formed icosahedral or decagonal quasicrystals

and structural changes in solid solutions could affect the com-positions They [27] observed that composition of ternaryquasicrystals most likely fall in the range of 18ndash22 at Mnwhich was close to the composition region of the stable 120583-Al4Mn phase The composition of reported T1 is close to

Journal of Materials 9

30 35 40 45 50 55 60 65 70 75 800

50

100

150

200

250

300

350C

ount

s

Position of 2120579

(a)

30 35 40 45 50 55 60 65 70 75 800

50

100

150

200

250

300

350

Cou

nts

Position of 2120579

(b)

30 35 40 45 50 55 60 65 70 75 800

50

100

150

200

250

300

Cou

nts

SiAl

Position of 2120579

Al4Mn1205912

(c)

Figure 10 (a) XRD spectrum of annealed sample 2 (b) XRD spectrum of annealed sample 3 (c) XRD spectrum of annealed sample 5

the homogeneity range of Al4Mn which indicated that T1

might be a quasicrystal of Al4Mnwith extended Zn solubility

1205913was observed in DC 3 (Al-Mn

13Zn87) and the com-

position was primarily determined as Al10Mn15Zn75 Several

key alloys were prepared to study this new compound Theactual compositions of these samples and the compositionsof the detected phases are listed in Table 2 The 120591

3phase has

a complex homogeneity range 9ndash13 at Al 11ndash15 at Mnand 75ndash77 at Zn as was determined by the analysis of DC3 (Al-Mn

13Zn87) and key samples 9 to 13 Sample 9 is an

example of these findings as shown in Figures 8(a) and 8(b)The sample contains residuals of the primary Al

8Mn5phase

that decomposes according to the peritectic reaction L+Al8Mn5rarr Al

11Mn4 The decomposition of Al

8Mn5was not

complete due to the slow kinetics of the peritectic reaction 1205913

phase formed a matrix in this alloyThe homogeneity ranges of the binary compounds were

determined using EPMA From the EPMA results Al11Mn4

exhibited ternary solubility reaching up to 4 at Zn Al4Mn

had the maximum ternary solubility of 6 at Zn Thedissolved Zn in Al-fcc was found to reach up to 45 atTernary homogeneity range of Al

8Mn5has been determined

by EPMA as 11 atZnThese observations also confirmed theresults which were inferred from DC 4 (Mn-Al

65Mn30Zn5)

Additionally another ternary phase 1205914was found in this

ternary system The composition of this phase is in the

region around Al23Mn16Zn61 However 120591

4is found to be

metastable As shown in Figure 8(c) three phases Al11Mn4

1205913 and 120591

4were found in sample 12 to be annealed at 400∘C

for 25 days After prolonged annealing for another 15 days 1205914

decomposed to provide more 1205913and Al

11Mn4

In order to verify the observations of the ternary com-pounds key alloys were studied using XRD The XRDpatterns of sample 1 are illustrated in Figure 9 Al-fcc andAl4Mn are positively identified in the XRD pattern Besides

there are several peaks which do not belong to any of theknown binary phases in the system Based on the resultsof phase identifications those peaks could correspond to1205911 Because of the lack of the reported prototype of 120591

1 the

peaks which belong to 1205911were hard to separate due to the

several overlapping peaks in the XRD pattern of this sampleThus the crystal structure of this compound could not bedetermined in the current study However the peaks whichcould belong to 120591

1have been labeled as shown in Figure 9

T3 phase reported by [24] denoted as 1205912in the current

study was confirmed through XRD analysis Three XRDspectra of sample 2 3 and 5 were used for this purpose Asshown in Figure 10 the XRD patterns of the three samplesare similar From 2120579 position 40∘ to 45∘ hump-like patternscan be observed due to peaks overlapping This is becauseAl4Mnhas very complex crystal structure and has around 550

atoms in a giant unit cell [34] During the X-ray scanning

10 Journal of Materials

Mn

Al8Mn5Al8Mn5

120573-Mn998400

Al11Mn4

50120583m

(a)

0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 340

10

20

30

40

50

60

70

80

90

100

Elem

ents

(at

)

Points number

MnZn

AlAl8Mn5

Al8Mn5120573-Mn998400

Al11Mn4

Al8Mn5

Al11Mn4

(b)

Figure 11 (a) Backscattered electron image of diffusion couple DC 4 (Mn-Al65

Mn30

Zn5

) (b) composition profile of line-scan in diffusioncouple DC 4 (Mn-Al

65

Mn30

Zn5

)

process the diffracted spectra of Al4Mn were overlapping

with other peaks at numerous positions and generate theseoverlapped patterns Using the crystallographic entry of T3from Pearsonrsquos database [34] T3 was positively identifiedamong XRD analysis Along with Al-fcc and Al

4Mn the

triangulation among those three phases was establishedXRD analysis of ternary compound 120591

3has similar issues

to 1205911as elucidated above Unfortunately too many peaks

were overlapping in a multiphase alloy and a single-phasesample representing 120591

3was not possible to prepareTherefore

the crystal structure of this compound has not been deter-mined either

33 Description of Ternary Solid Solutions

331 Homogeneity Range of Al8Mn5and Al

11Mn4 Al8Mn5

has wide homogeneity range in Al-Mn binary system How-ever it is difficult to estimate how much of Zn dissolvedin this compound from the results of DC 2 (Mn-Al

94Zn6)

Journal of Materials 11

Al8Mn5

Al11Mn4

80120583m

(a)

Al8Mn5

50120583m

(b)

20 25 30 35 40 45 50 550

100

200

300

400

500

600

Cou

nts

Position of 2120579

Al8Mn5

98 Al8Mn5

(c)

Figure 12 (a) Backscattered electron image of sample 14 (b) backscattered electron image of sample 15 (c) XRD spectrum of sample 15

Thus DC 4 (Mn-Al65Mn30Zn5) was prepared in order to

determine the homogeneity range of Al8Mn5in this ternary

system Because Al11Mn4has higher growth rate one end

member of DC 4 (Mn-Al65Mn30Zn5) has been selected near

the Al8Mn5region to increase the atomic exchange between

Al and Mn From the backscattered electron image of DC4 (Mn-Al

65Mn30Zn5) shown in Figure 11(a) Al

8Mn5formed

a thick layer and the color changed along with decreasingMn content which suggests the presence of a homogeneityrange Line-scan shown in Figure 11(b) was carried outto determine the homogeneity range of Al

8Mn5 In the

Al11Mn4+ Al8Mn5two-phase region dotted lines denote

the concentrations of elements in Al11Mn4and solid lines

represent the concentrations of elements in Al8Mn5 The

SEMEDS analysis showed that Al8Mn5has ternary solubility

of 9 at Zn and Al11Mn4has maximum ternary solubility

of 4 at Zn Al concentration in Al8Mn5layer varied from

49 at to 58 atAl11Mn4and Al

8Mn5showed extended ternary solubility

in this system at 400∘C In order to confirm the resultsobtained from previous diffusion couples four key alloys(14 to 17) were prepared The composition and phase iden-tification of these key samples are summarized in Table 2The phase relations obtained from EPMA showed greatconsistency with the XRD results Backscattered electronimage of sample 14 is shown in Figure 12(a) From EPMA

point analysis Al11Mn4has a ternary solubility of about 4 at

Zn and Al8Mn5has a maximum ternary solubility of 10 at

Zn These results were consistent with the previous EPMAobservation of samples 9 and 11 Figure 12(b) shows thatsample 15 contains mainly Al

8Mn5whose ternary solubility

was measured around 4 at Zn The XRD analysis also con-firmed that Al

8Mn5is dominating in sample 15 as shown in

Figure 12(c)There are a few unlabeled small peaks indicatingthe presence of Al

11Mn4traces which could not be identified

in the current study because of their low intensity

332 Single Region of 120576 Phase Controversy on whether120576 has three-phase separations reported in the assessmentof Okamoto and Tanner [15] is still not resolved In thecurrent study one end-member of DC 5 (Al-Mn

32Zn68)

has a composition in the 120576-phase region EPMA line-scanindicated that 120576-phase has continuous binary solubility rangesreaching fromMn

32Zn68to Mn

40Zn60at 400∘CThis finding

also corresponds to the Mn-Zn binary system which wasreported by [32 35] The backscattered electron image of DC5 (Al-Mn

32Zn68) is presented in Figure 13 Five phases have

been identified 120576 Al-rich 120573-Mn1015840 Al8Mn5 Al11Mn4 and Al-

fcc In the current experimental investigation the maximumsolubility of Zn in 120573-Mn1015840 was measured as 4 at Single 120576-phase region with the Mn content from 32 to 40 at was

12 Journal of Materials

Al8Mn5

120573-Mn998400

Al11Mn4

Al-fcc

Mn32Zn68(120576)

Figure 13 Backscattered electron image of DC 5 (Al-Mn32

Zn68

)

observed at 400∘C and nothing indicated the presence ofphase separation in this composition range From the resultsof sample 17 (Al

30Mn35Zn35) 120576-phase was found to have

limited ternary solubility of 4 at Al

34 Isothermal Section of Al-Mn-Zn System at 400∘C Com-bining the results which were obtained from the diffusioncouples with those obtained from the key alloys the Al-Mn-Zn isothermal section at 400∘C was constructed and pre-sented in Figure 14 Solid lines represent the experimentallyverified phase boundaries and ternary solubility of binaryphases Dotted lines are the estimated phase relationshipswhich were not confirmed in the current study They wereconstructed based on the Gibbs phase rule [36] and Schreine-makerrsquos rule [37] Grey blue and green areas indicate thesingle two-phase and three-phase regions separately asshown in Figure 14

4 Conclusion

The Al-Mn-Zn isothermal section at 400∘C was constructedbased on the current experimental results of diffusion coupletechnique and selected key alloys Phase relationships andsolubility limits have been determined for the ternary andbinary compounds The previously reported ternary com-pound T3 was confirmed in the current study and is denotedas 1205912in this paper Two new ternary compounds 120591

1and 1205913

have been found in this system at 400∘C 1205911does not show

significant solubility ranges and is considered stoichiometric1205913is a solid solution with a narrow homogeneity range

The formulae of the three Al-Mn-Zn ternary intermetalliccompounds are 120591

1 Al31Mn8Zn11 1205912 Al72Mn16Zn12 and 120591

3

Al119909Mn119910Zn119911(119909 = 9ndash13 at 119910 = 11ndash15 at 119911 = 75ndash77 at) A

single-phase region of Al8Mn5with extended solubility was

found in this system at 400∘C Based on the current findingsthe ternary solubilities of the Al

8Mn5 Al4Mn and Al

11Mn4

compounds have been determined as 10 at 6 at and 4 atZn respectively 120576 and Mn

5Zn21

exhibit their maximumsolubilities of 4 at and 5 at Al The solubility of Zn in120573-Mn1015840 has been found to be 4 at and 120573-Mn10158401015840 has ternarysolubility of 3 at Al

Mole

frac

tion

Al

0 20 40 60 80 100

0

20

40

60

80

100 0

20

40

60

80

100

Single-phase regionTwo-phase region

Mole fraction M

n

Zn

Mn

AlMole fraction Zn

400∘C

Al8Mn5

Al 8Mn 5

Al6MnAl4Mn

120573-Mn998400 120573-M

n998400

120573-Mn998400998400

Al11Mn4

Al12Mn MnZn13MnZn9

Mn5Zn21

120576

Three-phase region

1205912 1205911

Al-f

cc

Liqu

idZn

-HCP

120573-Mn998400 + 120573-Mn998400998400

120573-Mn 998400+ 120573-Mn 998400998400

+ 120576

Al8Mn5 + 120573- Mn998400

Al8Mn5 + 120576Al8Mn

5 + Mn5Zn

21 + 1205913

Al8Mn5 + Al11Mn4 + 12059131205911 + Al11Mn4 + 1205913

1205911 + Al-fcc + 1205913

Al8Mn5 + 120573-Mn 998400

+ 120576

Figure 14 Isothermal section of Al-Mn-Zn ternary system at 400∘Cconstructed by diffusion couples and key samples

Conflict of Interests

The authors declare that there is no conflict of interestsof any sort that might have influenced the discussions orconclusions of this paper

Acknowledgments

Financial support from General Motors of Canada Ltd andthe Natural Sciences and Engineering Research Councilof Canada (NSERC) through the CRD grant program isgratefully acknowledged The authors would also like toacknowledge the help of Mohammad Mezbahul-Islam ofMechanical Engineering Department Concordia Universityfor his valuable suggestions

References

[1] G S Cole and A M Sherman ldquoLight weight materials forautomotive applicationsrdquo Materials Characterization vol 35no 1 pp 3ndash9 1995

[2] S W Nam and B O Kong ldquoDevelopment of weldable highstrength alalloyrdquo KOSEF Technical Report 1993

[3] H S Cho and S W Nam ldquoA study of the low cycle fatigueproperties of weldable Al-Zn-Mg-Mn Alloy and Al 7039 invarious environmentsrdquo Journal of Korean Institute of Metals andMaterials vol 32 no 7 pp 765ndash770 1994

[4] M Ohno D Mirkovic and R Schmid-Fetzer ldquoLiquidus andsolidus temperatures of Mg-rich Mg-Al-Mn-Zn alloysrdquo ActaMaterialia vol 54 no 15 pp 3883ndash3891 2006

[5] N Gao Y H Liu and N-Y Tang ldquoAn experimental study ofthe liquid domain of the Zn-Fe-Al-Mn quaternary system at

Journal of Materials 13

460∘Crdquo Journal of Phase Equilibria and Diffusion vol 31 no 6pp 523ndash531 2010

[6] M A Khan and M Medraj ldquoThermodynamic descriptionof the Mg-Mn Al-Mn and Mg-Al-Mn systems using themodified quasichemical model for the liquid phasesrdquoMaterialsTransactions vol 50 no 5 pp 1113ndash1122 2009

[7] C Muller H Stadelmaier B Reinsch and G Petzow ldquoMet-allurgy of the magnetic 120591-phase in Mn-Al and Mn-Al-CrdquoZeitschrift fuer Metallkunde vol 87 no 7 pp 594ndash597 1996

[8] A Shukla and A D Pelton ldquoThermodynamic assessment of theAl-Mn andMg-Al-Mn systemsrdquo Journal of Phase Equilibria andDiffusion vol 30 no 1 pp 28ndash39 2009

[9] H Kono ldquoOn the ferromagnetic phase in manganese-aluminum systemrdquo Journal of the Physical Society of Japan vol13 no 12 pp 1444ndash1451 1958

[10] W Koster and E Wachtel ldquoConstitution and magnetic proper-ties of aluminum-manganese alloyswithmore than 5AtMnrdquoZeitschrift fuer Metallkunde vol 51 pp 271ndash280 1960

[11] Y Minamino T Yamane H Araki et al ldquoSolid solubilities ofmanganese and titanium in aluminum at 01 MPa and 21 GPardquoMetallurgical Transactions A vol 22 no 3 pp 783ndash786 1991

[12] H Okamoto ldquoAl-Mn (Aluminum-Manganese)rdquo Journal ofPhase Equilibria vol 18 no 4 pp 398ndash399 1997

[13] M A Taylor ldquoIntermetallig phases in the aluminiumman-ganese binary systemrdquo Acta Metallurgica vol 8 no 4 pp 256ndash262 1960

[14] S Wasiur-Rahman andMMedraj ldquoA thermodynamic descrip-tion of the Al-Ca-Zn ternary systemrdquoCalphad vol 33 no 3 pp584ndash598 2009

[15] H Okamoto and L E Tanner ldquoThe Mn-Zn (Manganese-Zinc)systemrdquo Bulletin of Alloy Phase Diagrams vol 11 no 4 pp 377ndash384 1990

[16] S Tezuka S Sakai and Y Nakagawa ldquoFerromagnetism of Mn-Zn alloyrdquo Journal of the Physical Society of Japan vol 15 no 5p 931 1960

[17] Y Nakagawa and T Hori ldquoMagnetic transition and crystaldistortion in MnHg andMnZn

3

rdquo Journal of the Physical Societyof Japan vol 17 no 8 pp 1313ndash1314 1962

[18] B Henderson and R J M Willcox ldquoLattice spacing relation-ships in hexagonal close-packed Silver-Zinc-Manganese alloysrdquoPhilosophical Magazine vol 9 no 101 pp 829ndash846 1964

[19] R A Farrar and H W King ldquoAxial ratios and solubility limitsof HCP 120578 and 120576 phases in the systems CdMn and ZnMnrdquoMetallography vol 3 no 1 pp 61ndash70 1970

[20] J L Liang Y Du C Z Liao et al ldquoExperimental investigationon the phase equilibria of the Mn-Ni-Zn system at 400∘CrdquoJournal of Alloys and Compounds vol 489 no 2 pp 362ndash3682010

[21] J L Liang Y Du Q Z Zhao et al ldquoDetermination of the phaseequilibria in the Mn-Sn-Zn system at 500∘ Crdquo MetallurgicalandMaterials Transactions A PhysicalMetallurgy andMaterialsScience vol 40 no 12 pp 2909ndash2918 2009

[22] H Xu X Xiong L Zhang YDu and PWang ldquoPhase equilibriaof the Mn-Si-Zn system at 600∘Crdquo Metallurgical and MaterialsTransactions A Physical Metallurgy and Materials Science vol40 no 9 pp 2042ndash2047 2009

[23] E Gebhardt ldquoDie zinkecke des dreistoffsystems zink-aluminium-manganrdquo Zeitschrift fur Metallkunde vol 34pp 259ndash263 1942

[24] G V Raynor and D W Wakeman ldquoThe intermetallic com-pound phases of the system Aluminium-Manganese-Zincrdquo

Proceedings of the Royal Society of London A Mathematical andPhysical Sciences vol 190 no 1020 pp 82ndash101 1947

[25] K Robinson ldquoThe determination of the crystal structure ofNi4

Mn11

Al60

rdquo Acta Crystallographica vol 7 part 6-7 pp 494ndash497 1954

[26] A Damjanovic ldquoThe structure analysis of the T3

(A1MnZn)compoundrdquo Acta Crystallographica vol 14 pp 982ndash987 1961

[27] R J Schaefer L A Bendersky D Shechtman W J Boettingerand F S Biancaniello ldquoIcosahedral and decagonal phase forma-tion in Al-Mn Alloysrdquo Metallurgical transactions A vol 17 no12 pp 2117ndash2125 1986

[28] A Singh S Ranganathan and L A Bendersky ldquoQuasicrys-talline phases and their approximants inAl-Mn-Zn alloysrdquoActaMaterialia vol 45 no 12 pp 5327ndash5336 1997

[29] J S Kirkaldy and L C Brown ldquoDiffusion behavior in theternarymultiphase systemsrdquoCanadianMetallurgicalQuarterlyvol 2 no 1 pp 90ndash115 1963

[30] J B Clark ldquoConventions for plotting the diffusion paths inmultiphase ternary diffusion couples on the isothermal sectionof a ternary phase diagramrdquo Transactions of the MetallurgicalSociety of AIME vol 227 pp 1250ndash1251 1963

[31] A A Kodentsov G F Bastin and F J J van Loo ldquoThe diffusioncouple technique in phase diagram determinationrdquo Journal ofAlloys and Compounds vol 320 no 2 pp 207ndash217 2001

[32] M A Khan Thermodynamic modeling of the MgndashMnndash(Al Zn)systems [MS thesis] Concordia University 2009

[33] PANalytical Ver22b (222) PANalytical Almelo The Nether-lands 2006

[34] H Putz and K Brandenburg Pearsonrsquos Crystal Data CrystalStructure Database for Inorganic Compounds CD-ROM Soft-ware Version 13

[35] P Ghosh and M Medraj ldquoThermodynamic calculation of theMg-Mn-Zn and Mg-Mn-Ce systems and re-optimization oftheir constitutive binariesrdquo Calphad Computer Coupling ofPhase Diagrams andThermochemistry vol 41 pp 89ndash107 2013

[36] A Prince Alloy Phase Equilibria Elsevier Amsterdam TheNetherland 1966

[37] L Y H John ldquoSchreinemakers rule as applied to non-degenerate ternary systemsrdquoThe Journal of Young Investigatorsvol 19 no 11 2009

Submit your manuscripts athttpwwwhindawicom

ScientificaHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CorrosionInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Polymer ScienceInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CeramicsJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CompositesJournal of

NanoparticlesJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

International Journal of

Biomaterials

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

NanoscienceJournal of

TextilesHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Journal of

NanotechnologyHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

CrystallographyJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CoatingsJournal of

Advances in

Materials Science and EngineeringHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Smart Materials Research

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

MetallurgyJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

BioMed Research International

MaterialsJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Nano

materials

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal ofNanomaterials

Journal of Materials 5

Al8Mn5

Al4MnMn 120573-Mn998400

120573-Mn998400998400

Al11Mn4

Al-fcc1205912

(a)

Al8Mn5

Al4MnMn

120573-Mn998400

120573-Mn998400998400

Al11Mn4

Al-fcc

1205912

(b)

0 20 40 60 80 100

0

20

40

60

80

100 0

20

40

60

80

100

Composition of detected phases

Mole fraction M

nMole

frac

tion

Al

Zn

Mn

Al

Diffusion path

DC2

25 days

Mole fraction Zn

400∘C

Al8Mn5

Al6MnAl4Mn

120573-Mn998400 120573-Mn998400998400

Al12MnMnZn13

MnZn9Mn5Zn21

120576

1205912

Al11Mn4

Al-f

cc

Liqu

idZn

-HCP

(c)

Mole

frac

tion

Al

0 20 40 60 80 100

0

20

40

60

80

100 0

20

40

60

80

100

15 days25 days

Mole fraction M

n

Zn

Mn

Al

Mole fraction Zn

400∘C

Al8Mn5

Al6MnAl4Mn

120573-Mn998400 120573-Mn998400998400

Al11Mn4

Al12MnMnZn13

MnZn9Mn5Zn21

120576

1205912

Al-f

cc

Liqu

idZn

-HCP

(d)

Figure 3 (a) Backscattered electron image of DC 2 (Mn-Al94

Zn6

) annealed at 400∘C for 15 days along with its schematic (b) backscatteredelectron image of DC 2 (Mn-Al

94

Zn6

) annealed at 400∘C for 25 days along with its schematic (c) diffusion path of DC 2 (Mn-Al94

Zn6

)annealed for 25 days (d) comparisons of DC 2 (Mn-Al

94

Zn6

) annealed at 15 days and 25 days

Al-fcc

Al4Mn

50120583m

1205911

Figure 4 Backscattered electron image of sample 1

DC 3 (Al-Mn13Zn87) was studied using the same

approach as for DC 1 (Al-Mn11Zn89) and DC 2 (Mn-

Al94Zn6) Four phases have been identified through EPMA

analysis 1205913 Al8Mn5 Al11Mn4 and Al-fcc EPMA point

analysis indicated that the 1205913ternary compound had the

composition of Al10Mn15Zn75 Other than this the results of

this diffusion couple only confirmed the data obtained fromDC 1 and 2Therefore the details of DC 3 (Al-Mn

13Zn87) are

not mentioned here to avoid repetition

32 Experimental Study of Key Alloys Ten key alloys wereprepared to verify the formation of phases reported in theliterature and confirm the presence of the ternary compounds1205911 1205912 and 120591

3found in this experimental study The actual

6 Journal of Materials

Al-fcc

Al4Mn

Al6Mn

20120583m

(a)

Al-fcc

Al4Mn

Al6Mn

(b)

Figure 5 (a) Backscattered electron image of as-cast sample 7 (b) backscattered electron image of annealed sample 7

30 35 40 45 50 55 60 65 70 75 80 850

50

100

150

200

250

Al 148

Cou

nts

Position of 2120579

Al4Mn 562

Al6Mn 29

(a)

30 35 40 45 50 55 60 65 70 75 80 850

100

200

300

400

500

Cou

nts

Al 108

Position of 2120579

Al4Mn 14

Al6Mn 752

(b)

Figure 6 (a) XRD spectrum of as-cast sample 7 (b) XRD spectrum of annealed sample 7

Al4Mn Al-fcc

1205912

Figure 7 Backscattered electron image of sample 3

composition of these key alloys and the composition of thedetected phases are presented in Table 2

The ternary compounds T1 (Al24Mn5Zn) and T2

(Al9Mn2Zn) [24] were not observed in this system at 400∘C

As shown in Table 2 key alloy 7 was prepared close tothe composition of T1 compound key alloys 5 and 6 weremade close to the composition of T2 compound HoweverT1 and T2 were not detected It should be mentioned thatRaynor and Wakeman [24] used only as-cast samples intheir study and reported compounds could be metastable orhigh temperature phases Furthermore they [24] have usedthe wet chemical analysis of small quantities of extractedcrystals which may cause errors in phase compositionsdetermination compared to EPMA point analysis usedin our work The existence of 120591

1phase was confirmed in

sample 1 as a stoichiometric compound with Al64Mn15Zn21

composition The microstructure of this alloy is shown inFigure 4 120591

1formed during a peritectic reaction which is hard

to be terminated during short annealing period Thereforethe primary phase Al

4Mn was not decomposed completely

even after annealing for 30 days Similar phenomenon wasalso observed in key sample 7 Figures 5(a) and 5(b) showthe as-cast and annealed microstructures of sample 7 It isclear that Al

4Mn (the white phase) formed as a primary

phase Al6Mn then formed according to the peritectic

reaction L + Al4Mn rarr Al

6Mn After annealing for 30 days

Journal of Materials 7

Table 2 The actual compositions of the key samples and the detected phases

Samplenumber

Actual compositionidentified by ICP (at) Phase identification

Composition ofidentified phasesby EPMA (at)

Al Mn Zn ByEPMA

ByXRD Al Mn Zn

1 44 16 40Al4Mn Al4Mn 74 20 61205911

64 15 21Al-fcc Al-fcc 55 0 45

2 75 13 121205912

1205912

73 15 12Al4Mn Al4Mn 74 20 6Al-fcc Al-fcc 78 0 22

3 78 15 71205912

1205912

75 14 11Al4Mn Al4Mn 75 20 5Al-fcc Al-fcc 88 0 12

4 79 10 111205912

1205912

72 16 12Al4Mn Al4Mn 76 20 4Al-fcc Al-fcc 79 0 21

5 74 16 101205912

1205912

73 15 12Al4Mn Al4Mn 74 20 6Al-fcc Al-fcc 75 0 25

6 74 15 111205912

1205912

72 15 13Al4Mn Al4Mn 74 20 6Al-fcc Al-fcc 80 0 20

7 84 12 4Al6Mn Al6Mn 86 14 0Al4Mn Al4Mn 75 20 5Al-fcc Al-fcc 95 0 5

8 82 11 7Al12Mn 92 8 0Al6Mn 83 15 2Al-fcc 96 0 4

9 21 14 651205913

12 11 77Al11Mn4 Al11Mn4 70 26 3Al8Mn5 Al8Mn5 56 37 7

10 16 14 701205913

12 11 771205914

23 16 61Al11Mn4 Al11Mn4 71 25 4

11 23 16 61

1205913

13 13 741205914

25 18 57Al11Mn4 Al11Mn4 69 27 4Al8Mn5 Al8Mn5 55 36 9

12 17 15 68Al11Mn4 Al11Mn4 70 26 41205913

13 11 761205914

23 16 61

13 18 22 60 1205913

10 15 75Al8Mn5 Al8Mn5 52ndash57 33ndash37 10ndash11

14 64 31 5 Al11Mn4 Al11Mn4 70 26 4Al8Mn5 Al8Mn5 55 34 10

15 56 37 7 Al8Mn5 Al8Mn5 57 39 4

16 55 35 10 Al11Mn4 Al11Mn4 70 27 3Al8Mn5 Al8Mn5 57 34 9

17 30 35 35 Al8Mn5 54 38 8120576 74 22 4

8 Journal of Materials

(a)

Al8Mn5

Al11Mn4

1205913

(b)

Al11Mn4

1205913

1205914

10120583m

(c)

Al11Mn4

1205913

100120583m

(d)

Figure 8 (a) Backscattered electron image of annealed sample 9 at 400∘C for 30 days (b) magnified area of sample 9 (c) backscatteredelectron image of sample 10 annealed at 400∘C for 25 days (d) backscattered electron image of sample 10 annealed at 400∘C for 40 days

30 35 40 45 50 55 60 65 70 75 800

50100150200250300350400450500550600650700

Al

Cou

nts

Position of 2120579

Al4Mn1205911

Figure 9 XRD spectrum of annealed sample 1

the amount of Al4Mn decreased and decomposed to Al

6Mn

The microstructure of annealed sample 7 is shown inFigure 5(b) Using XRD analysis the weight fraction ofAl4Mn and Al

6Mn in the as-cast sample was measured

as 562 and 29 respectively as shown in Figure 6(a)

The amount of Al4Mn and Al

6Mn changed dramatically

after annealing for 30 days to become 14 and 822as demonstrated in Figure 6(b) This variation indicatesperitectic decomposition upon annealing Due to the naturalsluggish kinetics of peritectic reaction the transformation ofAl4Mn to Al

6Mn requires very long time

The formation of 1205912was confirmed after analysis of key

alloys 2 to 6 The microstructure of sample 3 is shown inFigure 7 EPMA results indicated that 120591

2is a stoichiometric

compound with Al71Mn16Zn13

composition It has beenobserved that the Mn content of Al

4Mn varies in the range of

18ndash21 at which could be owing to the Zn substitution Thedissolved Zn in Al

4Mn was found to reach up to 6 at Sub-

stitution of third element could lead to the small variationsof compositions On the other hand these Mn content devia-tions could be due to the fact that Al

4Mn forms quasicrystals

The structure of quasicrystal may change under differentsolidification conditions [27] Schaefer et al [27] mentionedthat Al

4Mn formed icosahedral or decagonal quasicrystals

and structural changes in solid solutions could affect the com-positions They [27] observed that composition of ternaryquasicrystals most likely fall in the range of 18ndash22 at Mnwhich was close to the composition region of the stable 120583-Al4Mn phase The composition of reported T1 is close to

Journal of Materials 9

30 35 40 45 50 55 60 65 70 75 800

50

100

150

200

250

300

350C

ount

s

Position of 2120579

(a)

30 35 40 45 50 55 60 65 70 75 800

50

100

150

200

250

300

350

Cou

nts

Position of 2120579

(b)

30 35 40 45 50 55 60 65 70 75 800

50

100

150

200

250

300

Cou

nts

SiAl

Position of 2120579

Al4Mn1205912

(c)

Figure 10 (a) XRD spectrum of annealed sample 2 (b) XRD spectrum of annealed sample 3 (c) XRD spectrum of annealed sample 5

the homogeneity range of Al4Mn which indicated that T1

might be a quasicrystal of Al4Mnwith extended Zn solubility

1205913was observed in DC 3 (Al-Mn

13Zn87) and the com-

position was primarily determined as Al10Mn15Zn75 Several

key alloys were prepared to study this new compound Theactual compositions of these samples and the compositionsof the detected phases are listed in Table 2 The 120591

3phase has

a complex homogeneity range 9ndash13 at Al 11ndash15 at Mnand 75ndash77 at Zn as was determined by the analysis of DC3 (Al-Mn

13Zn87) and key samples 9 to 13 Sample 9 is an

example of these findings as shown in Figures 8(a) and 8(b)The sample contains residuals of the primary Al

8Mn5phase

that decomposes according to the peritectic reaction L+Al8Mn5rarr Al

11Mn4 The decomposition of Al

8Mn5was not

complete due to the slow kinetics of the peritectic reaction 1205913

phase formed a matrix in this alloyThe homogeneity ranges of the binary compounds were

determined using EPMA From the EPMA results Al11Mn4

exhibited ternary solubility reaching up to 4 at Zn Al4Mn

had the maximum ternary solubility of 6 at Zn Thedissolved Zn in Al-fcc was found to reach up to 45 atTernary homogeneity range of Al

8Mn5has been determined

by EPMA as 11 atZnThese observations also confirmed theresults which were inferred from DC 4 (Mn-Al

65Mn30Zn5)

Additionally another ternary phase 1205914was found in this

ternary system The composition of this phase is in the

region around Al23Mn16Zn61 However 120591

4is found to be

metastable As shown in Figure 8(c) three phases Al11Mn4

1205913 and 120591

4were found in sample 12 to be annealed at 400∘C

for 25 days After prolonged annealing for another 15 days 1205914

decomposed to provide more 1205913and Al

11Mn4

In order to verify the observations of the ternary com-pounds key alloys were studied using XRD The XRDpatterns of sample 1 are illustrated in Figure 9 Al-fcc andAl4Mn are positively identified in the XRD pattern Besides

there are several peaks which do not belong to any of theknown binary phases in the system Based on the resultsof phase identifications those peaks could correspond to1205911 Because of the lack of the reported prototype of 120591

1 the

peaks which belong to 1205911were hard to separate due to the

several overlapping peaks in the XRD pattern of this sampleThus the crystal structure of this compound could not bedetermined in the current study However the peaks whichcould belong to 120591

1have been labeled as shown in Figure 9

T3 phase reported by [24] denoted as 1205912in the current

study was confirmed through XRD analysis Three XRDspectra of sample 2 3 and 5 were used for this purpose Asshown in Figure 10 the XRD patterns of the three samplesare similar From 2120579 position 40∘ to 45∘ hump-like patternscan be observed due to peaks overlapping This is becauseAl4Mnhas very complex crystal structure and has around 550

atoms in a giant unit cell [34] During the X-ray scanning

10 Journal of Materials

Mn

Al8Mn5Al8Mn5

120573-Mn998400

Al11Mn4

50120583m

(a)

0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 340

10

20

30

40

50

60

70

80

90

100

Elem

ents

(at

)

Points number

MnZn

AlAl8Mn5

Al8Mn5120573-Mn998400

Al11Mn4

Al8Mn5

Al11Mn4

(b)

Figure 11 (a) Backscattered electron image of diffusion couple DC 4 (Mn-Al65

Mn30

Zn5

) (b) composition profile of line-scan in diffusioncouple DC 4 (Mn-Al

65

Mn30

Zn5

)

process the diffracted spectra of Al4Mn were overlapping

with other peaks at numerous positions and generate theseoverlapped patterns Using the crystallographic entry of T3from Pearsonrsquos database [34] T3 was positively identifiedamong XRD analysis Along with Al-fcc and Al

4Mn the

triangulation among those three phases was establishedXRD analysis of ternary compound 120591

3has similar issues

to 1205911as elucidated above Unfortunately too many peaks

were overlapping in a multiphase alloy and a single-phasesample representing 120591

3was not possible to prepareTherefore

the crystal structure of this compound has not been deter-mined either

33 Description of Ternary Solid Solutions

331 Homogeneity Range of Al8Mn5and Al

11Mn4 Al8Mn5

has wide homogeneity range in Al-Mn binary system How-ever it is difficult to estimate how much of Zn dissolvedin this compound from the results of DC 2 (Mn-Al

94Zn6)

Journal of Materials 11

Al8Mn5

Al11Mn4

80120583m

(a)

Al8Mn5

50120583m

(b)

20 25 30 35 40 45 50 550

100

200

300

400

500

600

Cou

nts

Position of 2120579

Al8Mn5

98 Al8Mn5

(c)

Figure 12 (a) Backscattered electron image of sample 14 (b) backscattered electron image of sample 15 (c) XRD spectrum of sample 15

Thus DC 4 (Mn-Al65Mn30Zn5) was prepared in order to

determine the homogeneity range of Al8Mn5in this ternary

system Because Al11Mn4has higher growth rate one end

member of DC 4 (Mn-Al65Mn30Zn5) has been selected near

the Al8Mn5region to increase the atomic exchange between

Al and Mn From the backscattered electron image of DC4 (Mn-Al

65Mn30Zn5) shown in Figure 11(a) Al

8Mn5formed

a thick layer and the color changed along with decreasingMn content which suggests the presence of a homogeneityrange Line-scan shown in Figure 11(b) was carried outto determine the homogeneity range of Al

8Mn5 In the

Al11Mn4+ Al8Mn5two-phase region dotted lines denote

the concentrations of elements in Al11Mn4and solid lines

represent the concentrations of elements in Al8Mn5 The

SEMEDS analysis showed that Al8Mn5has ternary solubility

of 9 at Zn and Al11Mn4has maximum ternary solubility

of 4 at Zn Al concentration in Al8Mn5layer varied from

49 at to 58 atAl11Mn4and Al

8Mn5showed extended ternary solubility

in this system at 400∘C In order to confirm the resultsobtained from previous diffusion couples four key alloys(14 to 17) were prepared The composition and phase iden-tification of these key samples are summarized in Table 2The phase relations obtained from EPMA showed greatconsistency with the XRD results Backscattered electronimage of sample 14 is shown in Figure 12(a) From EPMA

point analysis Al11Mn4has a ternary solubility of about 4 at

Zn and Al8Mn5has a maximum ternary solubility of 10 at

Zn These results were consistent with the previous EPMAobservation of samples 9 and 11 Figure 12(b) shows thatsample 15 contains mainly Al

8Mn5whose ternary solubility

was measured around 4 at Zn The XRD analysis also con-firmed that Al

8Mn5is dominating in sample 15 as shown in

Figure 12(c)There are a few unlabeled small peaks indicatingthe presence of Al

11Mn4traces which could not be identified

in the current study because of their low intensity

332 Single Region of 120576 Phase Controversy on whether120576 has three-phase separations reported in the assessmentof Okamoto and Tanner [15] is still not resolved In thecurrent study one end-member of DC 5 (Al-Mn

32Zn68)

has a composition in the 120576-phase region EPMA line-scanindicated that 120576-phase has continuous binary solubility rangesreaching fromMn

32Zn68to Mn

40Zn60at 400∘CThis finding

also corresponds to the Mn-Zn binary system which wasreported by [32 35] The backscattered electron image of DC5 (Al-Mn

32Zn68) is presented in Figure 13 Five phases have

been identified 120576 Al-rich 120573-Mn1015840 Al8Mn5 Al11Mn4 and Al-

fcc In the current experimental investigation the maximumsolubility of Zn in 120573-Mn1015840 was measured as 4 at Single 120576-phase region with the Mn content from 32 to 40 at was

12 Journal of Materials

Al8Mn5

120573-Mn998400

Al11Mn4

Al-fcc

Mn32Zn68(120576)

Figure 13 Backscattered electron image of DC 5 (Al-Mn32

Zn68

)

observed at 400∘C and nothing indicated the presence ofphase separation in this composition range From the resultsof sample 17 (Al

30Mn35Zn35) 120576-phase was found to have

limited ternary solubility of 4 at Al

34 Isothermal Section of Al-Mn-Zn System at 400∘C Com-bining the results which were obtained from the diffusioncouples with those obtained from the key alloys the Al-Mn-Zn isothermal section at 400∘C was constructed and pre-sented in Figure 14 Solid lines represent the experimentallyverified phase boundaries and ternary solubility of binaryphases Dotted lines are the estimated phase relationshipswhich were not confirmed in the current study They wereconstructed based on the Gibbs phase rule [36] and Schreine-makerrsquos rule [37] Grey blue and green areas indicate thesingle two-phase and three-phase regions separately asshown in Figure 14

4 Conclusion

The Al-Mn-Zn isothermal section at 400∘C was constructedbased on the current experimental results of diffusion coupletechnique and selected key alloys Phase relationships andsolubility limits have been determined for the ternary andbinary compounds The previously reported ternary com-pound T3 was confirmed in the current study and is denotedas 1205912in this paper Two new ternary compounds 120591

1and 1205913

have been found in this system at 400∘C 1205911does not show

significant solubility ranges and is considered stoichiometric1205913is a solid solution with a narrow homogeneity range

The formulae of the three Al-Mn-Zn ternary intermetalliccompounds are 120591

1 Al31Mn8Zn11 1205912 Al72Mn16Zn12 and 120591

3

Al119909Mn119910Zn119911(119909 = 9ndash13 at 119910 = 11ndash15 at 119911 = 75ndash77 at) A

single-phase region of Al8Mn5with extended solubility was

found in this system at 400∘C Based on the current findingsthe ternary solubilities of the Al

8Mn5 Al4Mn and Al

11Mn4

compounds have been determined as 10 at 6 at and 4 atZn respectively 120576 and Mn

5Zn21

exhibit their maximumsolubilities of 4 at and 5 at Al The solubility of Zn in120573-Mn1015840 has been found to be 4 at and 120573-Mn10158401015840 has ternarysolubility of 3 at Al

Mole

frac

tion

Al

0 20 40 60 80 100

0

20

40

60

80

100 0

20

40

60

80

100

Single-phase regionTwo-phase region

Mole fraction M

n

Zn

Mn

AlMole fraction Zn

400∘C

Al8Mn5

Al 8Mn 5

Al6MnAl4Mn

120573-Mn998400 120573-M

n998400

120573-Mn998400998400

Al11Mn4

Al12Mn MnZn13MnZn9

Mn5Zn21

120576

Three-phase region

1205912 1205911

Al-f

cc

Liqu

idZn

-HCP

120573-Mn998400 + 120573-Mn998400998400

120573-Mn 998400+ 120573-Mn 998400998400

+ 120576

Al8Mn5 + 120573- Mn998400

Al8Mn5 + 120576Al8Mn

5 + Mn5Zn

21 + 1205913

Al8Mn5 + Al11Mn4 + 12059131205911 + Al11Mn4 + 1205913

1205911 + Al-fcc + 1205913

Al8Mn5 + 120573-Mn 998400

+ 120576

Figure 14 Isothermal section of Al-Mn-Zn ternary system at 400∘Cconstructed by diffusion couples and key samples

Conflict of Interests

The authors declare that there is no conflict of interestsof any sort that might have influenced the discussions orconclusions of this paper

Acknowledgments

Financial support from General Motors of Canada Ltd andthe Natural Sciences and Engineering Research Councilof Canada (NSERC) through the CRD grant program isgratefully acknowledged The authors would also like toacknowledge the help of Mohammad Mezbahul-Islam ofMechanical Engineering Department Concordia Universityfor his valuable suggestions

References

[1] G S Cole and A M Sherman ldquoLight weight materials forautomotive applicationsrdquo Materials Characterization vol 35no 1 pp 3ndash9 1995

[2] S W Nam and B O Kong ldquoDevelopment of weldable highstrength alalloyrdquo KOSEF Technical Report 1993

[3] H S Cho and S W Nam ldquoA study of the low cycle fatigueproperties of weldable Al-Zn-Mg-Mn Alloy and Al 7039 invarious environmentsrdquo Journal of Korean Institute of Metals andMaterials vol 32 no 7 pp 765ndash770 1994

[4] M Ohno D Mirkovic and R Schmid-Fetzer ldquoLiquidus andsolidus temperatures of Mg-rich Mg-Al-Mn-Zn alloysrdquo ActaMaterialia vol 54 no 15 pp 3883ndash3891 2006

[5] N Gao Y H Liu and N-Y Tang ldquoAn experimental study ofthe liquid domain of the Zn-Fe-Al-Mn quaternary system at

Journal of Materials 13

460∘Crdquo Journal of Phase Equilibria and Diffusion vol 31 no 6pp 523ndash531 2010

[6] M A Khan and M Medraj ldquoThermodynamic descriptionof the Mg-Mn Al-Mn and Mg-Al-Mn systems using themodified quasichemical model for the liquid phasesrdquoMaterialsTransactions vol 50 no 5 pp 1113ndash1122 2009

[7] C Muller H Stadelmaier B Reinsch and G Petzow ldquoMet-allurgy of the magnetic 120591-phase in Mn-Al and Mn-Al-CrdquoZeitschrift fuer Metallkunde vol 87 no 7 pp 594ndash597 1996

[8] A Shukla and A D Pelton ldquoThermodynamic assessment of theAl-Mn andMg-Al-Mn systemsrdquo Journal of Phase Equilibria andDiffusion vol 30 no 1 pp 28ndash39 2009

[9] H Kono ldquoOn the ferromagnetic phase in manganese-aluminum systemrdquo Journal of the Physical Society of Japan vol13 no 12 pp 1444ndash1451 1958

[10] W Koster and E Wachtel ldquoConstitution and magnetic proper-ties of aluminum-manganese alloyswithmore than 5AtMnrdquoZeitschrift fuer Metallkunde vol 51 pp 271ndash280 1960

[11] Y Minamino T Yamane H Araki et al ldquoSolid solubilities ofmanganese and titanium in aluminum at 01 MPa and 21 GPardquoMetallurgical Transactions A vol 22 no 3 pp 783ndash786 1991

[12] H Okamoto ldquoAl-Mn (Aluminum-Manganese)rdquo Journal ofPhase Equilibria vol 18 no 4 pp 398ndash399 1997

[13] M A Taylor ldquoIntermetallig phases in the aluminiumman-ganese binary systemrdquo Acta Metallurgica vol 8 no 4 pp 256ndash262 1960

[14] S Wasiur-Rahman andMMedraj ldquoA thermodynamic descrip-tion of the Al-Ca-Zn ternary systemrdquoCalphad vol 33 no 3 pp584ndash598 2009

[15] H Okamoto and L E Tanner ldquoThe Mn-Zn (Manganese-Zinc)systemrdquo Bulletin of Alloy Phase Diagrams vol 11 no 4 pp 377ndash384 1990

[16] S Tezuka S Sakai and Y Nakagawa ldquoFerromagnetism of Mn-Zn alloyrdquo Journal of the Physical Society of Japan vol 15 no 5p 931 1960

[17] Y Nakagawa and T Hori ldquoMagnetic transition and crystaldistortion in MnHg andMnZn

3

rdquo Journal of the Physical Societyof Japan vol 17 no 8 pp 1313ndash1314 1962

[18] B Henderson and R J M Willcox ldquoLattice spacing relation-ships in hexagonal close-packed Silver-Zinc-Manganese alloysrdquoPhilosophical Magazine vol 9 no 101 pp 829ndash846 1964

[19] R A Farrar and H W King ldquoAxial ratios and solubility limitsof HCP 120578 and 120576 phases in the systems CdMn and ZnMnrdquoMetallography vol 3 no 1 pp 61ndash70 1970

[20] J L Liang Y Du C Z Liao et al ldquoExperimental investigationon the phase equilibria of the Mn-Ni-Zn system at 400∘CrdquoJournal of Alloys and Compounds vol 489 no 2 pp 362ndash3682010

[21] J L Liang Y Du Q Z Zhao et al ldquoDetermination of the phaseequilibria in the Mn-Sn-Zn system at 500∘ Crdquo MetallurgicalandMaterials Transactions A PhysicalMetallurgy andMaterialsScience vol 40 no 12 pp 2909ndash2918 2009

[22] H Xu X Xiong L Zhang YDu and PWang ldquoPhase equilibriaof the Mn-Si-Zn system at 600∘Crdquo Metallurgical and MaterialsTransactions A Physical Metallurgy and Materials Science vol40 no 9 pp 2042ndash2047 2009

[23] E Gebhardt ldquoDie zinkecke des dreistoffsystems zink-aluminium-manganrdquo Zeitschrift fur Metallkunde vol 34pp 259ndash263 1942

[24] G V Raynor and D W Wakeman ldquoThe intermetallic com-pound phases of the system Aluminium-Manganese-Zincrdquo

Proceedings of the Royal Society of London A Mathematical andPhysical Sciences vol 190 no 1020 pp 82ndash101 1947

[25] K Robinson ldquoThe determination of the crystal structure ofNi4

Mn11

Al60

rdquo Acta Crystallographica vol 7 part 6-7 pp 494ndash497 1954

[26] A Damjanovic ldquoThe structure analysis of the T3

(A1MnZn)compoundrdquo Acta Crystallographica vol 14 pp 982ndash987 1961

[27] R J Schaefer L A Bendersky D Shechtman W J Boettingerand F S Biancaniello ldquoIcosahedral and decagonal phase forma-tion in Al-Mn Alloysrdquo Metallurgical transactions A vol 17 no12 pp 2117ndash2125 1986

[28] A Singh S Ranganathan and L A Bendersky ldquoQuasicrys-talline phases and their approximants inAl-Mn-Zn alloysrdquoActaMaterialia vol 45 no 12 pp 5327ndash5336 1997

[29] J S Kirkaldy and L C Brown ldquoDiffusion behavior in theternarymultiphase systemsrdquoCanadianMetallurgicalQuarterlyvol 2 no 1 pp 90ndash115 1963

[30] J B Clark ldquoConventions for plotting the diffusion paths inmultiphase ternary diffusion couples on the isothermal sectionof a ternary phase diagramrdquo Transactions of the MetallurgicalSociety of AIME vol 227 pp 1250ndash1251 1963

[31] A A Kodentsov G F Bastin and F J J van Loo ldquoThe diffusioncouple technique in phase diagram determinationrdquo Journal ofAlloys and Compounds vol 320 no 2 pp 207ndash217 2001

[32] M A Khan Thermodynamic modeling of the MgndashMnndash(Al Zn)systems [MS thesis] Concordia University 2009

[33] PANalytical Ver22b (222) PANalytical Almelo The Nether-lands 2006

[34] H Putz and K Brandenburg Pearsonrsquos Crystal Data CrystalStructure Database for Inorganic Compounds CD-ROM Soft-ware Version 13

[35] P Ghosh and M Medraj ldquoThermodynamic calculation of theMg-Mn-Zn and Mg-Mn-Ce systems and re-optimization oftheir constitutive binariesrdquo Calphad Computer Coupling ofPhase Diagrams andThermochemistry vol 41 pp 89ndash107 2013

[36] A Prince Alloy Phase Equilibria Elsevier Amsterdam TheNetherland 1966

[37] L Y H John ldquoSchreinemakers rule as applied to non-degenerate ternary systemsrdquoThe Journal of Young Investigatorsvol 19 no 11 2009

Submit your manuscripts athttpwwwhindawicom

ScientificaHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CorrosionInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Polymer ScienceInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CeramicsJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CompositesJournal of

NanoparticlesJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

International Journal of

Biomaterials

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

NanoscienceJournal of

TextilesHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Journal of

NanotechnologyHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

CrystallographyJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CoatingsJournal of

Advances in

Materials Science and EngineeringHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Smart Materials Research

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

MetallurgyJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

BioMed Research International

MaterialsJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Nano

materials

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal ofNanomaterials

6 Journal of Materials

Al-fcc

Al4Mn

Al6Mn

20120583m

(a)

Al-fcc

Al4Mn

Al6Mn

(b)

Figure 5 (a) Backscattered electron image of as-cast sample 7 (b) backscattered electron image of annealed sample 7

30 35 40 45 50 55 60 65 70 75 80 850

50

100

150

200

250

Al 148

Cou

nts

Position of 2120579

Al4Mn 562

Al6Mn 29

(a)

30 35 40 45 50 55 60 65 70 75 80 850

100

200

300

400

500

Cou

nts

Al 108

Position of 2120579

Al4Mn 14

Al6Mn 752

(b)

Figure 6 (a) XRD spectrum of as-cast sample 7 (b) XRD spectrum of annealed sample 7

Al4Mn Al-fcc

1205912

Figure 7 Backscattered electron image of sample 3

composition of these key alloys and the composition of thedetected phases are presented in Table 2

The ternary compounds T1 (Al24Mn5Zn) and T2

(Al9Mn2Zn) [24] were not observed in this system at 400∘C

As shown in Table 2 key alloy 7 was prepared close tothe composition of T1 compound key alloys 5 and 6 weremade close to the composition of T2 compound HoweverT1 and T2 were not detected It should be mentioned thatRaynor and Wakeman [24] used only as-cast samples intheir study and reported compounds could be metastable orhigh temperature phases Furthermore they [24] have usedthe wet chemical analysis of small quantities of extractedcrystals which may cause errors in phase compositionsdetermination compared to EPMA point analysis usedin our work The existence of 120591

1phase was confirmed in

sample 1 as a stoichiometric compound with Al64Mn15Zn21

composition The microstructure of this alloy is shown inFigure 4 120591

1formed during a peritectic reaction which is hard

to be terminated during short annealing period Thereforethe primary phase Al

4Mn was not decomposed completely

even after annealing for 30 days Similar phenomenon wasalso observed in key sample 7 Figures 5(a) and 5(b) showthe as-cast and annealed microstructures of sample 7 It isclear that Al

4Mn (the white phase) formed as a primary

phase Al6Mn then formed according to the peritectic

reaction L + Al4Mn rarr Al

6Mn After annealing for 30 days

Journal of Materials 7

Table 2 The actual compositions of the key samples and the detected phases

Samplenumber

Actual compositionidentified by ICP (at) Phase identification

Composition ofidentified phasesby EPMA (at)

Al Mn Zn ByEPMA

ByXRD Al Mn Zn

1 44 16 40Al4Mn Al4Mn 74 20 61205911

64 15 21Al-fcc Al-fcc 55 0 45

2 75 13 121205912

1205912

73 15 12Al4Mn Al4Mn 74 20 6Al-fcc Al-fcc 78 0 22

3 78 15 71205912

1205912

75 14 11Al4Mn Al4Mn 75 20 5Al-fcc Al-fcc 88 0 12

4 79 10 111205912

1205912

72 16 12Al4Mn Al4Mn 76 20 4Al-fcc Al-fcc 79 0 21

5 74 16 101205912

1205912

73 15 12Al4Mn Al4Mn 74 20 6Al-fcc Al-fcc 75 0 25

6 74 15 111205912

1205912

72 15 13Al4Mn Al4Mn 74 20 6Al-fcc Al-fcc 80 0 20

7 84 12 4Al6Mn Al6Mn 86 14 0Al4Mn Al4Mn 75 20 5Al-fcc Al-fcc 95 0 5

8 82 11 7Al12Mn 92 8 0Al6Mn 83 15 2Al-fcc 96 0 4

9 21 14 651205913

12 11 77Al11Mn4 Al11Mn4 70 26 3Al8Mn5 Al8Mn5 56 37 7

10 16 14 701205913

12 11 771205914

23 16 61Al11Mn4 Al11Mn4 71 25 4

11 23 16 61

1205913

13 13 741205914

25 18 57Al11Mn4 Al11Mn4 69 27 4Al8Mn5 Al8Mn5 55 36 9

12 17 15 68Al11Mn4 Al11Mn4 70 26 41205913

13 11 761205914

23 16 61

13 18 22 60 1205913

10 15 75Al8Mn5 Al8Mn5 52ndash57 33ndash37 10ndash11

14 64 31 5 Al11Mn4 Al11Mn4 70 26 4Al8Mn5 Al8Mn5 55 34 10

15 56 37 7 Al8Mn5 Al8Mn5 57 39 4

16 55 35 10 Al11Mn4 Al11Mn4 70 27 3Al8Mn5 Al8Mn5 57 34 9

17 30 35 35 Al8Mn5 54 38 8120576 74 22 4

8 Journal of Materials

(a)

Al8Mn5

Al11Mn4

1205913

(b)

Al11Mn4

1205913

1205914

10120583m

(c)

Al11Mn4

1205913

100120583m

(d)

Figure 8 (a) Backscattered electron image of annealed sample 9 at 400∘C for 30 days (b) magnified area of sample 9 (c) backscatteredelectron image of sample 10 annealed at 400∘C for 25 days (d) backscattered electron image of sample 10 annealed at 400∘C for 40 days

30 35 40 45 50 55 60 65 70 75 800

50100150200250300350400450500550600650700

Al

Cou

nts

Position of 2120579

Al4Mn1205911

Figure 9 XRD spectrum of annealed sample 1

the amount of Al4Mn decreased and decomposed to Al

6Mn

The microstructure of annealed sample 7 is shown inFigure 5(b) Using XRD analysis the weight fraction ofAl4Mn and Al

6Mn in the as-cast sample was measured

as 562 and 29 respectively as shown in Figure 6(a)

The amount of Al4Mn and Al

6Mn changed dramatically

after annealing for 30 days to become 14 and 822as demonstrated in Figure 6(b) This variation indicatesperitectic decomposition upon annealing Due to the naturalsluggish kinetics of peritectic reaction the transformation ofAl4Mn to Al

6Mn requires very long time

The formation of 1205912was confirmed after analysis of key

alloys 2 to 6 The microstructure of sample 3 is shown inFigure 7 EPMA results indicated that 120591

2is a stoichiometric

compound with Al71Mn16Zn13

composition It has beenobserved that the Mn content of Al

4Mn varies in the range of

18ndash21 at which could be owing to the Zn substitution Thedissolved Zn in Al

4Mn was found to reach up to 6 at Sub-

stitution of third element could lead to the small variationsof compositions On the other hand these Mn content devia-tions could be due to the fact that Al

4Mn forms quasicrystals

The structure of quasicrystal may change under differentsolidification conditions [27] Schaefer et al [27] mentionedthat Al

4Mn formed icosahedral or decagonal quasicrystals

and structural changes in solid solutions could affect the com-positions They [27] observed that composition of ternaryquasicrystals most likely fall in the range of 18ndash22 at Mnwhich was close to the composition region of the stable 120583-Al4Mn phase The composition of reported T1 is close to

Journal of Materials 9

30 35 40 45 50 55 60 65 70 75 800

50

100

150

200

250

300

350C

ount

s

Position of 2120579

(a)

30 35 40 45 50 55 60 65 70 75 800

50

100

150

200

250

300

350

Cou

nts

Position of 2120579

(b)

30 35 40 45 50 55 60 65 70 75 800

50

100

150

200

250

300

Cou

nts

SiAl

Position of 2120579

Al4Mn1205912

(c)

Figure 10 (a) XRD spectrum of annealed sample 2 (b) XRD spectrum of annealed sample 3 (c) XRD spectrum of annealed sample 5

the homogeneity range of Al4Mn which indicated that T1

might be a quasicrystal of Al4Mnwith extended Zn solubility

1205913was observed in DC 3 (Al-Mn

13Zn87) and the com-

position was primarily determined as Al10Mn15Zn75 Several

key alloys were prepared to study this new compound Theactual compositions of these samples and the compositionsof the detected phases are listed in Table 2 The 120591

3phase has

a complex homogeneity range 9ndash13 at Al 11ndash15 at Mnand 75ndash77 at Zn as was determined by the analysis of DC3 (Al-Mn

13Zn87) and key samples 9 to 13 Sample 9 is an

example of these findings as shown in Figures 8(a) and 8(b)The sample contains residuals of the primary Al

8Mn5phase

that decomposes according to the peritectic reaction L+Al8Mn5rarr Al

11Mn4 The decomposition of Al

8Mn5was not

complete due to the slow kinetics of the peritectic reaction 1205913

phase formed a matrix in this alloyThe homogeneity ranges of the binary compounds were

determined using EPMA From the EPMA results Al11Mn4

exhibited ternary solubility reaching up to 4 at Zn Al4Mn

had the maximum ternary solubility of 6 at Zn Thedissolved Zn in Al-fcc was found to reach up to 45 atTernary homogeneity range of Al

8Mn5has been determined

by EPMA as 11 atZnThese observations also confirmed theresults which were inferred from DC 4 (Mn-Al

65Mn30Zn5)

Additionally another ternary phase 1205914was found in this

ternary system The composition of this phase is in the

region around Al23Mn16Zn61 However 120591

4is found to be

metastable As shown in Figure 8(c) three phases Al11Mn4

1205913 and 120591

4were found in sample 12 to be annealed at 400∘C

for 25 days After prolonged annealing for another 15 days 1205914

decomposed to provide more 1205913and Al

11Mn4

In order to verify the observations of the ternary com-pounds key alloys were studied using XRD The XRDpatterns of sample 1 are illustrated in Figure 9 Al-fcc andAl4Mn are positively identified in the XRD pattern Besides

there are several peaks which do not belong to any of theknown binary phases in the system Based on the resultsof phase identifications those peaks could correspond to1205911 Because of the lack of the reported prototype of 120591

1 the

peaks which belong to 1205911were hard to separate due to the

several overlapping peaks in the XRD pattern of this sampleThus the crystal structure of this compound could not bedetermined in the current study However the peaks whichcould belong to 120591

1have been labeled as shown in Figure 9

T3 phase reported by [24] denoted as 1205912in the current

study was confirmed through XRD analysis Three XRDspectra of sample 2 3 and 5 were used for this purpose Asshown in Figure 10 the XRD patterns of the three samplesare similar From 2120579 position 40∘ to 45∘ hump-like patternscan be observed due to peaks overlapping This is becauseAl4Mnhas very complex crystal structure and has around 550

atoms in a giant unit cell [34] During the X-ray scanning

10 Journal of Materials

Mn

Al8Mn5Al8Mn5

120573-Mn998400

Al11Mn4

50120583m

(a)

0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 340

10

20

30

40

50

60

70

80

90

100

Elem

ents

(at

)

Points number

MnZn

AlAl8Mn5

Al8Mn5120573-Mn998400

Al11Mn4

Al8Mn5

Al11Mn4

(b)

Figure 11 (a) Backscattered electron image of diffusion couple DC 4 (Mn-Al65

Mn30

Zn5

) (b) composition profile of line-scan in diffusioncouple DC 4 (Mn-Al

65

Mn30

Zn5

)

process the diffracted spectra of Al4Mn were overlapping

with other peaks at numerous positions and generate theseoverlapped patterns Using the crystallographic entry of T3from Pearsonrsquos database [34] T3 was positively identifiedamong XRD analysis Along with Al-fcc and Al

4Mn the

triangulation among those three phases was establishedXRD analysis of ternary compound 120591

3has similar issues

to 1205911as elucidated above Unfortunately too many peaks

were overlapping in a multiphase alloy and a single-phasesample representing 120591

3was not possible to prepareTherefore

the crystal structure of this compound has not been deter-mined either

33 Description of Ternary Solid Solutions

331 Homogeneity Range of Al8Mn5and Al

11Mn4 Al8Mn5

has wide homogeneity range in Al-Mn binary system How-ever it is difficult to estimate how much of Zn dissolvedin this compound from the results of DC 2 (Mn-Al

94Zn6)

Journal of Materials 11

Al8Mn5

Al11Mn4

80120583m

(a)

Al8Mn5

50120583m

(b)

20 25 30 35 40 45 50 550

100

200

300

400

500

600

Cou

nts

Position of 2120579

Al8Mn5

98 Al8Mn5

(c)

Figure 12 (a) Backscattered electron image of sample 14 (b) backscattered electron image of sample 15 (c) XRD spectrum of sample 15

Thus DC 4 (Mn-Al65Mn30Zn5) was prepared in order to

determine the homogeneity range of Al8Mn5in this ternary

system Because Al11Mn4has higher growth rate one end

member of DC 4 (Mn-Al65Mn30Zn5) has been selected near

the Al8Mn5region to increase the atomic exchange between

Al and Mn From the backscattered electron image of DC4 (Mn-Al

65Mn30Zn5) shown in Figure 11(a) Al

8Mn5formed

a thick layer and the color changed along with decreasingMn content which suggests the presence of a homogeneityrange Line-scan shown in Figure 11(b) was carried outto determine the homogeneity range of Al

8Mn5 In the

Al11Mn4+ Al8Mn5two-phase region dotted lines denote

the concentrations of elements in Al11Mn4and solid lines

represent the concentrations of elements in Al8Mn5 The

SEMEDS analysis showed that Al8Mn5has ternary solubility

of 9 at Zn and Al11Mn4has maximum ternary solubility

of 4 at Zn Al concentration in Al8Mn5layer varied from

49 at to 58 atAl11Mn4and Al

8Mn5showed extended ternary solubility

in this system at 400∘C In order to confirm the resultsobtained from previous diffusion couples four key alloys(14 to 17) were prepared The composition and phase iden-tification of these key samples are summarized in Table 2The phase relations obtained from EPMA showed greatconsistency with the XRD results Backscattered electronimage of sample 14 is shown in Figure 12(a) From EPMA

point analysis Al11Mn4has a ternary solubility of about 4 at

Zn and Al8Mn5has a maximum ternary solubility of 10 at

Zn These results were consistent with the previous EPMAobservation of samples 9 and 11 Figure 12(b) shows thatsample 15 contains mainly Al

8Mn5whose ternary solubility

was measured around 4 at Zn The XRD analysis also con-firmed that Al

8Mn5is dominating in sample 15 as shown in

Figure 12(c)There are a few unlabeled small peaks indicatingthe presence of Al

11Mn4traces which could not be identified

in the current study because of their low intensity

332 Single Region of 120576 Phase Controversy on whether120576 has three-phase separations reported in the assessmentof Okamoto and Tanner [15] is still not resolved In thecurrent study one end-member of DC 5 (Al-Mn

32Zn68)

has a composition in the 120576-phase region EPMA line-scanindicated that 120576-phase has continuous binary solubility rangesreaching fromMn

32Zn68to Mn

40Zn60at 400∘CThis finding

also corresponds to the Mn-Zn binary system which wasreported by [32 35] The backscattered electron image of DC5 (Al-Mn

32Zn68) is presented in Figure 13 Five phases have

been identified 120576 Al-rich 120573-Mn1015840 Al8Mn5 Al11Mn4 and Al-

fcc In the current experimental investigation the maximumsolubility of Zn in 120573-Mn1015840 was measured as 4 at Single 120576-phase region with the Mn content from 32 to 40 at was

12 Journal of Materials

Al8Mn5

120573-Mn998400

Al11Mn4

Al-fcc

Mn32Zn68(120576)

Figure 13 Backscattered electron image of DC 5 (Al-Mn32

Zn68

)

observed at 400∘C and nothing indicated the presence ofphase separation in this composition range From the resultsof sample 17 (Al

30Mn35Zn35) 120576-phase was found to have

limited ternary solubility of 4 at Al

34 Isothermal Section of Al-Mn-Zn System at 400∘C Com-bining the results which were obtained from the diffusioncouples with those obtained from the key alloys the Al-Mn-Zn isothermal section at 400∘C was constructed and pre-sented in Figure 14 Solid lines represent the experimentallyverified phase boundaries and ternary solubility of binaryphases Dotted lines are the estimated phase relationshipswhich were not confirmed in the current study They wereconstructed based on the Gibbs phase rule [36] and Schreine-makerrsquos rule [37] Grey blue and green areas indicate thesingle two-phase and three-phase regions separately asshown in Figure 14

4 Conclusion

The Al-Mn-Zn isothermal section at 400∘C was constructedbased on the current experimental results of diffusion coupletechnique and selected key alloys Phase relationships andsolubility limits have been determined for the ternary andbinary compounds The previously reported ternary com-pound T3 was confirmed in the current study and is denotedas 1205912in this paper Two new ternary compounds 120591

1and 1205913

have been found in this system at 400∘C 1205911does not show

significant solubility ranges and is considered stoichiometric1205913is a solid solution with a narrow homogeneity range

The formulae of the three Al-Mn-Zn ternary intermetalliccompounds are 120591

1 Al31Mn8Zn11 1205912 Al72Mn16Zn12 and 120591

3

Al119909Mn119910Zn119911(119909 = 9ndash13 at 119910 = 11ndash15 at 119911 = 75ndash77 at) A

single-phase region of Al8Mn5with extended solubility was

found in this system at 400∘C Based on the current findingsthe ternary solubilities of the Al

8Mn5 Al4Mn and Al

11Mn4

compounds have been determined as 10 at 6 at and 4 atZn respectively 120576 and Mn

5Zn21

exhibit their maximumsolubilities of 4 at and 5 at Al The solubility of Zn in120573-Mn1015840 has been found to be 4 at and 120573-Mn10158401015840 has ternarysolubility of 3 at Al

Mole

frac

tion

Al

0 20 40 60 80 100

0

20

40

60

80

100 0

20

40

60

80

100

Single-phase regionTwo-phase region

Mole fraction M

n

Zn

Mn

AlMole fraction Zn

400∘C

Al8Mn5

Al 8Mn 5

Al6MnAl4Mn

120573-Mn998400 120573-M

n998400

120573-Mn998400998400

Al11Mn4

Al12Mn MnZn13MnZn9

Mn5Zn21

120576

Three-phase region

1205912 1205911

Al-f

cc

Liqu

idZn

-HCP

120573-Mn998400 + 120573-Mn998400998400

120573-Mn 998400+ 120573-Mn 998400998400

+ 120576

Al8Mn5 + 120573- Mn998400

Al8Mn5 + 120576Al8Mn

5 + Mn5Zn

21 + 1205913

Al8Mn5 + Al11Mn4 + 12059131205911 + Al11Mn4 + 1205913

1205911 + Al-fcc + 1205913

Al8Mn5 + 120573-Mn 998400

+ 120576

Figure 14 Isothermal section of Al-Mn-Zn ternary system at 400∘Cconstructed by diffusion couples and key samples

Conflict of Interests

The authors declare that there is no conflict of interestsof any sort that might have influenced the discussions orconclusions of this paper

Acknowledgments

Financial support from General Motors of Canada Ltd andthe Natural Sciences and Engineering Research Councilof Canada (NSERC) through the CRD grant program isgratefully acknowledged The authors would also like toacknowledge the help of Mohammad Mezbahul-Islam ofMechanical Engineering Department Concordia Universityfor his valuable suggestions

References

[1] G S Cole and A M Sherman ldquoLight weight materials forautomotive applicationsrdquo Materials Characterization vol 35no 1 pp 3ndash9 1995

[2] S W Nam and B O Kong ldquoDevelopment of weldable highstrength alalloyrdquo KOSEF Technical Report 1993

[3] H S Cho and S W Nam ldquoA study of the low cycle fatigueproperties of weldable Al-Zn-Mg-Mn Alloy and Al 7039 invarious environmentsrdquo Journal of Korean Institute of Metals andMaterials vol 32 no 7 pp 765ndash770 1994

[4] M Ohno D Mirkovic and R Schmid-Fetzer ldquoLiquidus andsolidus temperatures of Mg-rich Mg-Al-Mn-Zn alloysrdquo ActaMaterialia vol 54 no 15 pp 3883ndash3891 2006

[5] N Gao Y H Liu and N-Y Tang ldquoAn experimental study ofthe liquid domain of the Zn-Fe-Al-Mn quaternary system at

Journal of Materials 13

460∘Crdquo Journal of Phase Equilibria and Diffusion vol 31 no 6pp 523ndash531 2010

[6] M A Khan and M Medraj ldquoThermodynamic descriptionof the Mg-Mn Al-Mn and Mg-Al-Mn systems using themodified quasichemical model for the liquid phasesrdquoMaterialsTransactions vol 50 no 5 pp 1113ndash1122 2009

[7] C Muller H Stadelmaier B Reinsch and G Petzow ldquoMet-allurgy of the magnetic 120591-phase in Mn-Al and Mn-Al-CrdquoZeitschrift fuer Metallkunde vol 87 no 7 pp 594ndash597 1996

[8] A Shukla and A D Pelton ldquoThermodynamic assessment of theAl-Mn andMg-Al-Mn systemsrdquo Journal of Phase Equilibria andDiffusion vol 30 no 1 pp 28ndash39 2009

[9] H Kono ldquoOn the ferromagnetic phase in manganese-aluminum systemrdquo Journal of the Physical Society of Japan vol13 no 12 pp 1444ndash1451 1958

[10] W Koster and E Wachtel ldquoConstitution and magnetic proper-ties of aluminum-manganese alloyswithmore than 5AtMnrdquoZeitschrift fuer Metallkunde vol 51 pp 271ndash280 1960

[11] Y Minamino T Yamane H Araki et al ldquoSolid solubilities ofmanganese and titanium in aluminum at 01 MPa and 21 GPardquoMetallurgical Transactions A vol 22 no 3 pp 783ndash786 1991

[12] H Okamoto ldquoAl-Mn (Aluminum-Manganese)rdquo Journal ofPhase Equilibria vol 18 no 4 pp 398ndash399 1997

[13] M A Taylor ldquoIntermetallig phases in the aluminiumman-ganese binary systemrdquo Acta Metallurgica vol 8 no 4 pp 256ndash262 1960

[14] S Wasiur-Rahman andMMedraj ldquoA thermodynamic descrip-tion of the Al-Ca-Zn ternary systemrdquoCalphad vol 33 no 3 pp584ndash598 2009

[15] H Okamoto and L E Tanner ldquoThe Mn-Zn (Manganese-Zinc)systemrdquo Bulletin of Alloy Phase Diagrams vol 11 no 4 pp 377ndash384 1990

[16] S Tezuka S Sakai and Y Nakagawa ldquoFerromagnetism of Mn-Zn alloyrdquo Journal of the Physical Society of Japan vol 15 no 5p 931 1960

[17] Y Nakagawa and T Hori ldquoMagnetic transition and crystaldistortion in MnHg andMnZn

3

rdquo Journal of the Physical Societyof Japan vol 17 no 8 pp 1313ndash1314 1962

[18] B Henderson and R J M Willcox ldquoLattice spacing relation-ships in hexagonal close-packed Silver-Zinc-Manganese alloysrdquoPhilosophical Magazine vol 9 no 101 pp 829ndash846 1964

[19] R A Farrar and H W King ldquoAxial ratios and solubility limitsof HCP 120578 and 120576 phases in the systems CdMn and ZnMnrdquoMetallography vol 3 no 1 pp 61ndash70 1970

[20] J L Liang Y Du C Z Liao et al ldquoExperimental investigationon the phase equilibria of the Mn-Ni-Zn system at 400∘CrdquoJournal of Alloys and Compounds vol 489 no 2 pp 362ndash3682010

[21] J L Liang Y Du Q Z Zhao et al ldquoDetermination of the phaseequilibria in the Mn-Sn-Zn system at 500∘ Crdquo MetallurgicalandMaterials Transactions A PhysicalMetallurgy andMaterialsScience vol 40 no 12 pp 2909ndash2918 2009

[22] H Xu X Xiong L Zhang YDu and PWang ldquoPhase equilibriaof the Mn-Si-Zn system at 600∘Crdquo Metallurgical and MaterialsTransactions A Physical Metallurgy and Materials Science vol40 no 9 pp 2042ndash2047 2009

[23] E Gebhardt ldquoDie zinkecke des dreistoffsystems zink-aluminium-manganrdquo Zeitschrift fur Metallkunde vol 34pp 259ndash263 1942

[24] G V Raynor and D W Wakeman ldquoThe intermetallic com-pound phases of the system Aluminium-Manganese-Zincrdquo

Proceedings of the Royal Society of London A Mathematical andPhysical Sciences vol 190 no 1020 pp 82ndash101 1947

[25] K Robinson ldquoThe determination of the crystal structure ofNi4

Mn11

Al60

rdquo Acta Crystallographica vol 7 part 6-7 pp 494ndash497 1954

[26] A Damjanovic ldquoThe structure analysis of the T3

(A1MnZn)compoundrdquo Acta Crystallographica vol 14 pp 982ndash987 1961

[27] R J Schaefer L A Bendersky D Shechtman W J Boettingerand F S Biancaniello ldquoIcosahedral and decagonal phase forma-tion in Al-Mn Alloysrdquo Metallurgical transactions A vol 17 no12 pp 2117ndash2125 1986

[28] A Singh S Ranganathan and L A Bendersky ldquoQuasicrys-talline phases and their approximants inAl-Mn-Zn alloysrdquoActaMaterialia vol 45 no 12 pp 5327ndash5336 1997

[29] J S Kirkaldy and L C Brown ldquoDiffusion behavior in theternarymultiphase systemsrdquoCanadianMetallurgicalQuarterlyvol 2 no 1 pp 90ndash115 1963

[30] J B Clark ldquoConventions for plotting the diffusion paths inmultiphase ternary diffusion couples on the isothermal sectionof a ternary phase diagramrdquo Transactions of the MetallurgicalSociety of AIME vol 227 pp 1250ndash1251 1963

[31] A A Kodentsov G F Bastin and F J J van Loo ldquoThe diffusioncouple technique in phase diagram determinationrdquo Journal ofAlloys and Compounds vol 320 no 2 pp 207ndash217 2001

[32] M A Khan Thermodynamic modeling of the MgndashMnndash(Al Zn)systems [MS thesis] Concordia University 2009

[33] PANalytical Ver22b (222) PANalytical Almelo The Nether-lands 2006

[34] H Putz and K Brandenburg Pearsonrsquos Crystal Data CrystalStructure Database for Inorganic Compounds CD-ROM Soft-ware Version 13

[35] P Ghosh and M Medraj ldquoThermodynamic calculation of theMg-Mn-Zn and Mg-Mn-Ce systems and re-optimization oftheir constitutive binariesrdquo Calphad Computer Coupling ofPhase Diagrams andThermochemistry vol 41 pp 89ndash107 2013

[36] A Prince Alloy Phase Equilibria Elsevier Amsterdam TheNetherland 1966

[37] L Y H John ldquoSchreinemakers rule as applied to non-degenerate ternary systemsrdquoThe Journal of Young Investigatorsvol 19 no 11 2009

Submit your manuscripts athttpwwwhindawicom

ScientificaHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CorrosionInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Polymer ScienceInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CeramicsJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CompositesJournal of

NanoparticlesJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

International Journal of

Biomaterials

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

NanoscienceJournal of

TextilesHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Journal of

NanotechnologyHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

CrystallographyJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CoatingsJournal of

Advances in

Materials Science and EngineeringHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Smart Materials Research

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

MetallurgyJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

BioMed Research International

MaterialsJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Nano

materials

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal ofNanomaterials

Journal of Materials 7

Table 2 The actual compositions of the key samples and the detected phases

Samplenumber

Actual compositionidentified by ICP (at) Phase identification

Composition ofidentified phasesby EPMA (at)

Al Mn Zn ByEPMA

ByXRD Al Mn Zn

1 44 16 40Al4Mn Al4Mn 74 20 61205911

64 15 21Al-fcc Al-fcc 55 0 45

2 75 13 121205912

1205912

73 15 12Al4Mn Al4Mn 74 20 6Al-fcc Al-fcc 78 0 22

3 78 15 71205912

1205912

75 14 11Al4Mn Al4Mn 75 20 5Al-fcc Al-fcc 88 0 12

4 79 10 111205912

1205912

72 16 12Al4Mn Al4Mn 76 20 4Al-fcc Al-fcc 79 0 21

5 74 16 101205912

1205912

73 15 12Al4Mn Al4Mn 74 20 6Al-fcc Al-fcc 75 0 25

6 74 15 111205912

1205912

72 15 13Al4Mn Al4Mn 74 20 6Al-fcc Al-fcc 80 0 20

7 84 12 4Al6Mn Al6Mn 86 14 0Al4Mn Al4Mn 75 20 5Al-fcc Al-fcc 95 0 5

8 82 11 7Al12Mn 92 8 0Al6Mn 83 15 2Al-fcc 96 0 4

9 21 14 651205913

12 11 77Al11Mn4 Al11Mn4 70 26 3Al8Mn5 Al8Mn5 56 37 7

10 16 14 701205913

12 11 771205914

23 16 61Al11Mn4 Al11Mn4 71 25 4

11 23 16 61

1205913

13 13 741205914

25 18 57Al11Mn4 Al11Mn4 69 27 4Al8Mn5 Al8Mn5 55 36 9

12 17 15 68Al11Mn4 Al11Mn4 70 26 41205913

13 11 761205914

23 16 61

13 18 22 60 1205913

10 15 75Al8Mn5 Al8Mn5 52ndash57 33ndash37 10ndash11

14 64 31 5 Al11Mn4 Al11Mn4 70 26 4Al8Mn5 Al8Mn5 55 34 10

15 56 37 7 Al8Mn5 Al8Mn5 57 39 4

16 55 35 10 Al11Mn4 Al11Mn4 70 27 3Al8Mn5 Al8Mn5 57 34 9

17 30 35 35 Al8Mn5 54 38 8120576 74 22 4

8 Journal of Materials

(a)

Al8Mn5

Al11Mn4

1205913

(b)

Al11Mn4

1205913

1205914

10120583m

(c)

Al11Mn4

1205913

100120583m

(d)

Figure 8 (a) Backscattered electron image of annealed sample 9 at 400∘C for 30 days (b) magnified area of sample 9 (c) backscatteredelectron image of sample 10 annealed at 400∘C for 25 days (d) backscattered electron image of sample 10 annealed at 400∘C for 40 days

30 35 40 45 50 55 60 65 70 75 800

50100150200250300350400450500550600650700

Al

Cou

nts

Position of 2120579

Al4Mn1205911

Figure 9 XRD spectrum of annealed sample 1

the amount of Al4Mn decreased and decomposed to Al

6Mn

The microstructure of annealed sample 7 is shown inFigure 5(b) Using XRD analysis the weight fraction ofAl4Mn and Al

6Mn in the as-cast sample was measured

as 562 and 29 respectively as shown in Figure 6(a)

The amount of Al4Mn and Al

6Mn changed dramatically

after annealing for 30 days to become 14 and 822as demonstrated in Figure 6(b) This variation indicatesperitectic decomposition upon annealing Due to the naturalsluggish kinetics of peritectic reaction the transformation ofAl4Mn to Al

6Mn requires very long time

The formation of 1205912was confirmed after analysis of key

alloys 2 to 6 The microstructure of sample 3 is shown inFigure 7 EPMA results indicated that 120591

2is a stoichiometric

compound with Al71Mn16Zn13

composition It has beenobserved that the Mn content of Al

4Mn varies in the range of

18ndash21 at which could be owing to the Zn substitution Thedissolved Zn in Al

4Mn was found to reach up to 6 at Sub-

stitution of third element could lead to the small variationsof compositions On the other hand these Mn content devia-tions could be due to the fact that Al

4Mn forms quasicrystals

The structure of quasicrystal may change under differentsolidification conditions [27] Schaefer et al [27] mentionedthat Al

4Mn formed icosahedral or decagonal quasicrystals

and structural changes in solid solutions could affect the com-positions They [27] observed that composition of ternaryquasicrystals most likely fall in the range of 18ndash22 at Mnwhich was close to the composition region of the stable 120583-Al4Mn phase The composition of reported T1 is close to

Journal of Materials 9

30 35 40 45 50 55 60 65 70 75 800

50

100

150

200

250

300

350C

ount

s

Position of 2120579

(a)

30 35 40 45 50 55 60 65 70 75 800

50

100

150

200

250

300

350

Cou

nts

Position of 2120579

(b)

30 35 40 45 50 55 60 65 70 75 800

50

100

150

200

250

300

Cou

nts

SiAl

Position of 2120579

Al4Mn1205912

(c)

Figure 10 (a) XRD spectrum of annealed sample 2 (b) XRD spectrum of annealed sample 3 (c) XRD spectrum of annealed sample 5

the homogeneity range of Al4Mn which indicated that T1

might be a quasicrystal of Al4Mnwith extended Zn solubility

1205913was observed in DC 3 (Al-Mn

13Zn87) and the com-

position was primarily determined as Al10Mn15Zn75 Several

key alloys were prepared to study this new compound Theactual compositions of these samples and the compositionsof the detected phases are listed in Table 2 The 120591

3phase has

a complex homogeneity range 9ndash13 at Al 11ndash15 at Mnand 75ndash77 at Zn as was determined by the analysis of DC3 (Al-Mn

13Zn87) and key samples 9 to 13 Sample 9 is an

example of these findings as shown in Figures 8(a) and 8(b)The sample contains residuals of the primary Al

8Mn5phase

that decomposes according to the peritectic reaction L+Al8Mn5rarr Al

11Mn4 The decomposition of Al

8Mn5was not

complete due to the slow kinetics of the peritectic reaction 1205913

phase formed a matrix in this alloyThe homogeneity ranges of the binary compounds were

determined using EPMA From the EPMA results Al11Mn4

exhibited ternary solubility reaching up to 4 at Zn Al4Mn

had the maximum ternary solubility of 6 at Zn Thedissolved Zn in Al-fcc was found to reach up to 45 atTernary homogeneity range of Al

8Mn5has been determined

by EPMA as 11 atZnThese observations also confirmed theresults which were inferred from DC 4 (Mn-Al

65Mn30Zn5)

Additionally another ternary phase 1205914was found in this

ternary system The composition of this phase is in the

region around Al23Mn16Zn61 However 120591

4is found to be

metastable As shown in Figure 8(c) three phases Al11Mn4

1205913 and 120591

4were found in sample 12 to be annealed at 400∘C

for 25 days After prolonged annealing for another 15 days 1205914

decomposed to provide more 1205913and Al

11Mn4

In order to verify the observations of the ternary com-pounds key alloys were studied using XRD The XRDpatterns of sample 1 are illustrated in Figure 9 Al-fcc andAl4Mn are positively identified in the XRD pattern Besides

there are several peaks which do not belong to any of theknown binary phases in the system Based on the resultsof phase identifications those peaks could correspond to1205911 Because of the lack of the reported prototype of 120591

1 the

peaks which belong to 1205911were hard to separate due to the

several overlapping peaks in the XRD pattern of this sampleThus the crystal structure of this compound could not bedetermined in the current study However the peaks whichcould belong to 120591

1have been labeled as shown in Figure 9

T3 phase reported by [24] denoted as 1205912in the current

study was confirmed through XRD analysis Three XRDspectra of sample 2 3 and 5 were used for this purpose Asshown in Figure 10 the XRD patterns of the three samplesare similar From 2120579 position 40∘ to 45∘ hump-like patternscan be observed due to peaks overlapping This is becauseAl4Mnhas very complex crystal structure and has around 550

atoms in a giant unit cell [34] During the X-ray scanning

10 Journal of Materials

Mn

Al8Mn5Al8Mn5

120573-Mn998400

Al11Mn4

50120583m

(a)

0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 340

10

20

30

40

50

60

70

80

90

100

Elem

ents

(at

)

Points number

MnZn

AlAl8Mn5

Al8Mn5120573-Mn998400

Al11Mn4

Al8Mn5

Al11Mn4

(b)

Figure 11 (a) Backscattered electron image of diffusion couple DC 4 (Mn-Al65

Mn30

Zn5

) (b) composition profile of line-scan in diffusioncouple DC 4 (Mn-Al

65

Mn30

Zn5

)

process the diffracted spectra of Al4Mn were overlapping

with other peaks at numerous positions and generate theseoverlapped patterns Using the crystallographic entry of T3from Pearsonrsquos database [34] T3 was positively identifiedamong XRD analysis Along with Al-fcc and Al

4Mn the

triangulation among those three phases was establishedXRD analysis of ternary compound 120591

3has similar issues

to 1205911as elucidated above Unfortunately too many peaks

were overlapping in a multiphase alloy and a single-phasesample representing 120591

3was not possible to prepareTherefore

the crystal structure of this compound has not been deter-mined either

33 Description of Ternary Solid Solutions

331 Homogeneity Range of Al8Mn5and Al

11Mn4 Al8Mn5

has wide homogeneity range in Al-Mn binary system How-ever it is difficult to estimate how much of Zn dissolvedin this compound from the results of DC 2 (Mn-Al

94Zn6)

Journal of Materials 11

Al8Mn5

Al11Mn4

80120583m

(a)

Al8Mn5

50120583m

(b)

20 25 30 35 40 45 50 550

100

200

300

400

500

600

Cou

nts

Position of 2120579

Al8Mn5

98 Al8Mn5

(c)

Figure 12 (a) Backscattered electron image of sample 14 (b) backscattered electron image of sample 15 (c) XRD spectrum of sample 15

Thus DC 4 (Mn-Al65Mn30Zn5) was prepared in order to

determine the homogeneity range of Al8Mn5in this ternary

system Because Al11Mn4has higher growth rate one end

member of DC 4 (Mn-Al65Mn30Zn5) has been selected near

the Al8Mn5region to increase the atomic exchange between

Al and Mn From the backscattered electron image of DC4 (Mn-Al

65Mn30Zn5) shown in Figure 11(a) Al

8Mn5formed

a thick layer and the color changed along with decreasingMn content which suggests the presence of a homogeneityrange Line-scan shown in Figure 11(b) was carried outto determine the homogeneity range of Al

8Mn5 In the

Al11Mn4+ Al8Mn5two-phase region dotted lines denote

the concentrations of elements in Al11Mn4and solid lines

represent the concentrations of elements in Al8Mn5 The

SEMEDS analysis showed that Al8Mn5has ternary solubility

of 9 at Zn and Al11Mn4has maximum ternary solubility

of 4 at Zn Al concentration in Al8Mn5layer varied from

49 at to 58 atAl11Mn4and Al

8Mn5showed extended ternary solubility

in this system at 400∘C In order to confirm the resultsobtained from previous diffusion couples four key alloys(14 to 17) were prepared The composition and phase iden-tification of these key samples are summarized in Table 2The phase relations obtained from EPMA showed greatconsistency with the XRD results Backscattered electronimage of sample 14 is shown in Figure 12(a) From EPMA

point analysis Al11Mn4has a ternary solubility of about 4 at

Zn and Al8Mn5has a maximum ternary solubility of 10 at

Zn These results were consistent with the previous EPMAobservation of samples 9 and 11 Figure 12(b) shows thatsample 15 contains mainly Al

8Mn5whose ternary solubility

was measured around 4 at Zn The XRD analysis also con-firmed that Al

8Mn5is dominating in sample 15 as shown in

Figure 12(c)There are a few unlabeled small peaks indicatingthe presence of Al

11Mn4traces which could not be identified

in the current study because of their low intensity

332 Single Region of 120576 Phase Controversy on whether120576 has three-phase separations reported in the assessmentof Okamoto and Tanner [15] is still not resolved In thecurrent study one end-member of DC 5 (Al-Mn

32Zn68)

has a composition in the 120576-phase region EPMA line-scanindicated that 120576-phase has continuous binary solubility rangesreaching fromMn

32Zn68to Mn

40Zn60at 400∘CThis finding

also corresponds to the Mn-Zn binary system which wasreported by [32 35] The backscattered electron image of DC5 (Al-Mn

32Zn68) is presented in Figure 13 Five phases have

been identified 120576 Al-rich 120573-Mn1015840 Al8Mn5 Al11Mn4 and Al-

fcc In the current experimental investigation the maximumsolubility of Zn in 120573-Mn1015840 was measured as 4 at Single 120576-phase region with the Mn content from 32 to 40 at was

12 Journal of Materials

Al8Mn5

120573-Mn998400

Al11Mn4

Al-fcc

Mn32Zn68(120576)

Figure 13 Backscattered electron image of DC 5 (Al-Mn32

Zn68

)

observed at 400∘C and nothing indicated the presence ofphase separation in this composition range From the resultsof sample 17 (Al

30Mn35Zn35) 120576-phase was found to have

limited ternary solubility of 4 at Al

34 Isothermal Section of Al-Mn-Zn System at 400∘C Com-bining the results which were obtained from the diffusioncouples with those obtained from the key alloys the Al-Mn-Zn isothermal section at 400∘C was constructed and pre-sented in Figure 14 Solid lines represent the experimentallyverified phase boundaries and ternary solubility of binaryphases Dotted lines are the estimated phase relationshipswhich were not confirmed in the current study They wereconstructed based on the Gibbs phase rule [36] and Schreine-makerrsquos rule [37] Grey blue and green areas indicate thesingle two-phase and three-phase regions separately asshown in Figure 14

4 Conclusion

The Al-Mn-Zn isothermal section at 400∘C was constructedbased on the current experimental results of diffusion coupletechnique and selected key alloys Phase relationships andsolubility limits have been determined for the ternary andbinary compounds The previously reported ternary com-pound T3 was confirmed in the current study and is denotedas 1205912in this paper Two new ternary compounds 120591

1and 1205913

have been found in this system at 400∘C 1205911does not show

significant solubility ranges and is considered stoichiometric1205913is a solid solution with a narrow homogeneity range

The formulae of the three Al-Mn-Zn ternary intermetalliccompounds are 120591

1 Al31Mn8Zn11 1205912 Al72Mn16Zn12 and 120591

3

Al119909Mn119910Zn119911(119909 = 9ndash13 at 119910 = 11ndash15 at 119911 = 75ndash77 at) A

single-phase region of Al8Mn5with extended solubility was

found in this system at 400∘C Based on the current findingsthe ternary solubilities of the Al

8Mn5 Al4Mn and Al

11Mn4

compounds have been determined as 10 at 6 at and 4 atZn respectively 120576 and Mn

5Zn21

exhibit their maximumsolubilities of 4 at and 5 at Al The solubility of Zn in120573-Mn1015840 has been found to be 4 at and 120573-Mn10158401015840 has ternarysolubility of 3 at Al

Mole

frac

tion

Al

0 20 40 60 80 100

0

20

40

60

80

100 0

20

40

60

80

100

Single-phase regionTwo-phase region

Mole fraction M

n

Zn

Mn

AlMole fraction Zn

400∘C

Al8Mn5

Al 8Mn 5

Al6MnAl4Mn

120573-Mn998400 120573-M

n998400

120573-Mn998400998400

Al11Mn4

Al12Mn MnZn13MnZn9

Mn5Zn21

120576

Three-phase region

1205912 1205911

Al-f

cc

Liqu

idZn

-HCP

120573-Mn998400 + 120573-Mn998400998400

120573-Mn 998400+ 120573-Mn 998400998400

+ 120576

Al8Mn5 + 120573- Mn998400

Al8Mn5 + 120576Al8Mn

5 + Mn5Zn

21 + 1205913

Al8Mn5 + Al11Mn4 + 12059131205911 + Al11Mn4 + 1205913

1205911 + Al-fcc + 1205913

Al8Mn5 + 120573-Mn 998400

+ 120576

Figure 14 Isothermal section of Al-Mn-Zn ternary system at 400∘Cconstructed by diffusion couples and key samples

Conflict of Interests

The authors declare that there is no conflict of interestsof any sort that might have influenced the discussions orconclusions of this paper

Acknowledgments

Financial support from General Motors of Canada Ltd andthe Natural Sciences and Engineering Research Councilof Canada (NSERC) through the CRD grant program isgratefully acknowledged The authors would also like toacknowledge the help of Mohammad Mezbahul-Islam ofMechanical Engineering Department Concordia Universityfor his valuable suggestions

References

[1] G S Cole and A M Sherman ldquoLight weight materials forautomotive applicationsrdquo Materials Characterization vol 35no 1 pp 3ndash9 1995

[2] S W Nam and B O Kong ldquoDevelopment of weldable highstrength alalloyrdquo KOSEF Technical Report 1993

[3] H S Cho and S W Nam ldquoA study of the low cycle fatigueproperties of weldable Al-Zn-Mg-Mn Alloy and Al 7039 invarious environmentsrdquo Journal of Korean Institute of Metals andMaterials vol 32 no 7 pp 765ndash770 1994

[4] M Ohno D Mirkovic and R Schmid-Fetzer ldquoLiquidus andsolidus temperatures of Mg-rich Mg-Al-Mn-Zn alloysrdquo ActaMaterialia vol 54 no 15 pp 3883ndash3891 2006

[5] N Gao Y H Liu and N-Y Tang ldquoAn experimental study ofthe liquid domain of the Zn-Fe-Al-Mn quaternary system at

Journal of Materials 13

460∘Crdquo Journal of Phase Equilibria and Diffusion vol 31 no 6pp 523ndash531 2010

[6] M A Khan and M Medraj ldquoThermodynamic descriptionof the Mg-Mn Al-Mn and Mg-Al-Mn systems using themodified quasichemical model for the liquid phasesrdquoMaterialsTransactions vol 50 no 5 pp 1113ndash1122 2009

[7] C Muller H Stadelmaier B Reinsch and G Petzow ldquoMet-allurgy of the magnetic 120591-phase in Mn-Al and Mn-Al-CrdquoZeitschrift fuer Metallkunde vol 87 no 7 pp 594ndash597 1996

[8] A Shukla and A D Pelton ldquoThermodynamic assessment of theAl-Mn andMg-Al-Mn systemsrdquo Journal of Phase Equilibria andDiffusion vol 30 no 1 pp 28ndash39 2009

[9] H Kono ldquoOn the ferromagnetic phase in manganese-aluminum systemrdquo Journal of the Physical Society of Japan vol13 no 12 pp 1444ndash1451 1958

[10] W Koster and E Wachtel ldquoConstitution and magnetic proper-ties of aluminum-manganese alloyswithmore than 5AtMnrdquoZeitschrift fuer Metallkunde vol 51 pp 271ndash280 1960

[11] Y Minamino T Yamane H Araki et al ldquoSolid solubilities ofmanganese and titanium in aluminum at 01 MPa and 21 GPardquoMetallurgical Transactions A vol 22 no 3 pp 783ndash786 1991

[12] H Okamoto ldquoAl-Mn (Aluminum-Manganese)rdquo Journal ofPhase Equilibria vol 18 no 4 pp 398ndash399 1997

[13] M A Taylor ldquoIntermetallig phases in the aluminiumman-ganese binary systemrdquo Acta Metallurgica vol 8 no 4 pp 256ndash262 1960

[14] S Wasiur-Rahman andMMedraj ldquoA thermodynamic descrip-tion of the Al-Ca-Zn ternary systemrdquoCalphad vol 33 no 3 pp584ndash598 2009

[15] H Okamoto and L E Tanner ldquoThe Mn-Zn (Manganese-Zinc)systemrdquo Bulletin of Alloy Phase Diagrams vol 11 no 4 pp 377ndash384 1990

[16] S Tezuka S Sakai and Y Nakagawa ldquoFerromagnetism of Mn-Zn alloyrdquo Journal of the Physical Society of Japan vol 15 no 5p 931 1960

[17] Y Nakagawa and T Hori ldquoMagnetic transition and crystaldistortion in MnHg andMnZn

3

rdquo Journal of the Physical Societyof Japan vol 17 no 8 pp 1313ndash1314 1962

[18] B Henderson and R J M Willcox ldquoLattice spacing relation-ships in hexagonal close-packed Silver-Zinc-Manganese alloysrdquoPhilosophical Magazine vol 9 no 101 pp 829ndash846 1964

[19] R A Farrar and H W King ldquoAxial ratios and solubility limitsof HCP 120578 and 120576 phases in the systems CdMn and ZnMnrdquoMetallography vol 3 no 1 pp 61ndash70 1970

[20] J L Liang Y Du C Z Liao et al ldquoExperimental investigationon the phase equilibria of the Mn-Ni-Zn system at 400∘CrdquoJournal of Alloys and Compounds vol 489 no 2 pp 362ndash3682010

[21] J L Liang Y Du Q Z Zhao et al ldquoDetermination of the phaseequilibria in the Mn-Sn-Zn system at 500∘ Crdquo MetallurgicalandMaterials Transactions A PhysicalMetallurgy andMaterialsScience vol 40 no 12 pp 2909ndash2918 2009

[22] H Xu X Xiong L Zhang YDu and PWang ldquoPhase equilibriaof the Mn-Si-Zn system at 600∘Crdquo Metallurgical and MaterialsTransactions A Physical Metallurgy and Materials Science vol40 no 9 pp 2042ndash2047 2009

[23] E Gebhardt ldquoDie zinkecke des dreistoffsystems zink-aluminium-manganrdquo Zeitschrift fur Metallkunde vol 34pp 259ndash263 1942

[24] G V Raynor and D W Wakeman ldquoThe intermetallic com-pound phases of the system Aluminium-Manganese-Zincrdquo

Proceedings of the Royal Society of London A Mathematical andPhysical Sciences vol 190 no 1020 pp 82ndash101 1947

[25] K Robinson ldquoThe determination of the crystal structure ofNi4

Mn11

Al60

rdquo Acta Crystallographica vol 7 part 6-7 pp 494ndash497 1954

[26] A Damjanovic ldquoThe structure analysis of the T3

(A1MnZn)compoundrdquo Acta Crystallographica vol 14 pp 982ndash987 1961

[27] R J Schaefer L A Bendersky D Shechtman W J Boettingerand F S Biancaniello ldquoIcosahedral and decagonal phase forma-tion in Al-Mn Alloysrdquo Metallurgical transactions A vol 17 no12 pp 2117ndash2125 1986

[28] A Singh S Ranganathan and L A Bendersky ldquoQuasicrys-talline phases and their approximants inAl-Mn-Zn alloysrdquoActaMaterialia vol 45 no 12 pp 5327ndash5336 1997

[29] J S Kirkaldy and L C Brown ldquoDiffusion behavior in theternarymultiphase systemsrdquoCanadianMetallurgicalQuarterlyvol 2 no 1 pp 90ndash115 1963

[30] J B Clark ldquoConventions for plotting the diffusion paths inmultiphase ternary diffusion couples on the isothermal sectionof a ternary phase diagramrdquo Transactions of the MetallurgicalSociety of AIME vol 227 pp 1250ndash1251 1963

[31] A A Kodentsov G F Bastin and F J J van Loo ldquoThe diffusioncouple technique in phase diagram determinationrdquo Journal ofAlloys and Compounds vol 320 no 2 pp 207ndash217 2001

[32] M A Khan Thermodynamic modeling of the MgndashMnndash(Al Zn)systems [MS thesis] Concordia University 2009

[33] PANalytical Ver22b (222) PANalytical Almelo The Nether-lands 2006

[34] H Putz and K Brandenburg Pearsonrsquos Crystal Data CrystalStructure Database for Inorganic Compounds CD-ROM Soft-ware Version 13

[35] P Ghosh and M Medraj ldquoThermodynamic calculation of theMg-Mn-Zn and Mg-Mn-Ce systems and re-optimization oftheir constitutive binariesrdquo Calphad Computer Coupling ofPhase Diagrams andThermochemistry vol 41 pp 89ndash107 2013

[36] A Prince Alloy Phase Equilibria Elsevier Amsterdam TheNetherland 1966

[37] L Y H John ldquoSchreinemakers rule as applied to non-degenerate ternary systemsrdquoThe Journal of Young Investigatorsvol 19 no 11 2009

Submit your manuscripts athttpwwwhindawicom

ScientificaHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CorrosionInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Polymer ScienceInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CeramicsJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CompositesJournal of

NanoparticlesJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

International Journal of

Biomaterials

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

NanoscienceJournal of

TextilesHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Journal of

NanotechnologyHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

CrystallographyJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CoatingsJournal of

Advances in

Materials Science and EngineeringHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Smart Materials Research

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

MetallurgyJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

BioMed Research International

MaterialsJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Nano

materials

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal ofNanomaterials

8 Journal of Materials

(a)

Al8Mn5

Al11Mn4

1205913

(b)

Al11Mn4

1205913

1205914

10120583m

(c)

Al11Mn4

1205913

100120583m

(d)

Figure 8 (a) Backscattered electron image of annealed sample 9 at 400∘C for 30 days (b) magnified area of sample 9 (c) backscatteredelectron image of sample 10 annealed at 400∘C for 25 days (d) backscattered electron image of sample 10 annealed at 400∘C for 40 days

30 35 40 45 50 55 60 65 70 75 800

50100150200250300350400450500550600650700

Al

Cou

nts

Position of 2120579

Al4Mn1205911

Figure 9 XRD spectrum of annealed sample 1

the amount of Al4Mn decreased and decomposed to Al

6Mn

The microstructure of annealed sample 7 is shown inFigure 5(b) Using XRD analysis the weight fraction ofAl4Mn and Al

6Mn in the as-cast sample was measured

as 562 and 29 respectively as shown in Figure 6(a)

The amount of Al4Mn and Al

6Mn changed dramatically

after annealing for 30 days to become 14 and 822as demonstrated in Figure 6(b) This variation indicatesperitectic decomposition upon annealing Due to the naturalsluggish kinetics of peritectic reaction the transformation ofAl4Mn to Al

6Mn requires very long time

The formation of 1205912was confirmed after analysis of key

alloys 2 to 6 The microstructure of sample 3 is shown inFigure 7 EPMA results indicated that 120591

2is a stoichiometric

compound with Al71Mn16Zn13

composition It has beenobserved that the Mn content of Al

4Mn varies in the range of

18ndash21 at which could be owing to the Zn substitution Thedissolved Zn in Al

4Mn was found to reach up to 6 at Sub-

stitution of third element could lead to the small variationsof compositions On the other hand these Mn content devia-tions could be due to the fact that Al

4Mn forms quasicrystals

The structure of quasicrystal may change under differentsolidification conditions [27] Schaefer et al [27] mentionedthat Al

4Mn formed icosahedral or decagonal quasicrystals

and structural changes in solid solutions could affect the com-positions They [27] observed that composition of ternaryquasicrystals most likely fall in the range of 18ndash22 at Mnwhich was close to the composition region of the stable 120583-Al4Mn phase The composition of reported T1 is close to

Journal of Materials 9

30 35 40 45 50 55 60 65 70 75 800

50

100

150

200

250

300

350C

ount

s

Position of 2120579

(a)

30 35 40 45 50 55 60 65 70 75 800

50

100

150

200

250

300

350

Cou

nts

Position of 2120579

(b)

30 35 40 45 50 55 60 65 70 75 800

50

100

150

200

250

300

Cou

nts

SiAl

Position of 2120579

Al4Mn1205912

(c)

Figure 10 (a) XRD spectrum of annealed sample 2 (b) XRD spectrum of annealed sample 3 (c) XRD spectrum of annealed sample 5

the homogeneity range of Al4Mn which indicated that T1

might be a quasicrystal of Al4Mnwith extended Zn solubility

1205913was observed in DC 3 (Al-Mn

13Zn87) and the com-

position was primarily determined as Al10Mn15Zn75 Several

key alloys were prepared to study this new compound Theactual compositions of these samples and the compositionsof the detected phases are listed in Table 2 The 120591

3phase has

a complex homogeneity range 9ndash13 at Al 11ndash15 at Mnand 75ndash77 at Zn as was determined by the analysis of DC3 (Al-Mn

13Zn87) and key samples 9 to 13 Sample 9 is an

example of these findings as shown in Figures 8(a) and 8(b)The sample contains residuals of the primary Al

8Mn5phase

that decomposes according to the peritectic reaction L+Al8Mn5rarr Al

11Mn4 The decomposition of Al

8Mn5was not

complete due to the slow kinetics of the peritectic reaction 1205913

phase formed a matrix in this alloyThe homogeneity ranges of the binary compounds were

determined using EPMA From the EPMA results Al11Mn4

exhibited ternary solubility reaching up to 4 at Zn Al4Mn

had the maximum ternary solubility of 6 at Zn Thedissolved Zn in Al-fcc was found to reach up to 45 atTernary homogeneity range of Al

8Mn5has been determined

by EPMA as 11 atZnThese observations also confirmed theresults which were inferred from DC 4 (Mn-Al

65Mn30Zn5)

Additionally another ternary phase 1205914was found in this

ternary system The composition of this phase is in the

region around Al23Mn16Zn61 However 120591

4is found to be

metastable As shown in Figure 8(c) three phases Al11Mn4

1205913 and 120591

4were found in sample 12 to be annealed at 400∘C

for 25 days After prolonged annealing for another 15 days 1205914

decomposed to provide more 1205913and Al

11Mn4

In order to verify the observations of the ternary com-pounds key alloys were studied using XRD The XRDpatterns of sample 1 are illustrated in Figure 9 Al-fcc andAl4Mn are positively identified in the XRD pattern Besides

there are several peaks which do not belong to any of theknown binary phases in the system Based on the resultsof phase identifications those peaks could correspond to1205911 Because of the lack of the reported prototype of 120591

1 the

peaks which belong to 1205911were hard to separate due to the

several overlapping peaks in the XRD pattern of this sampleThus the crystal structure of this compound could not bedetermined in the current study However the peaks whichcould belong to 120591

1have been labeled as shown in Figure 9

T3 phase reported by [24] denoted as 1205912in the current

study was confirmed through XRD analysis Three XRDspectra of sample 2 3 and 5 were used for this purpose Asshown in Figure 10 the XRD patterns of the three samplesare similar From 2120579 position 40∘ to 45∘ hump-like patternscan be observed due to peaks overlapping This is becauseAl4Mnhas very complex crystal structure and has around 550

atoms in a giant unit cell [34] During the X-ray scanning

10 Journal of Materials

Mn

Al8Mn5Al8Mn5

120573-Mn998400

Al11Mn4

50120583m

(a)

0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 340

10

20

30

40

50

60

70

80

90

100

Elem

ents

(at

)

Points number

MnZn

AlAl8Mn5

Al8Mn5120573-Mn998400

Al11Mn4

Al8Mn5

Al11Mn4

(b)

Figure 11 (a) Backscattered electron image of diffusion couple DC 4 (Mn-Al65

Mn30

Zn5

) (b) composition profile of line-scan in diffusioncouple DC 4 (Mn-Al

65

Mn30

Zn5

)

process the diffracted spectra of Al4Mn were overlapping

with other peaks at numerous positions and generate theseoverlapped patterns Using the crystallographic entry of T3from Pearsonrsquos database [34] T3 was positively identifiedamong XRD analysis Along with Al-fcc and Al

4Mn the

triangulation among those three phases was establishedXRD analysis of ternary compound 120591

3has similar issues

to 1205911as elucidated above Unfortunately too many peaks

were overlapping in a multiphase alloy and a single-phasesample representing 120591

3was not possible to prepareTherefore

the crystal structure of this compound has not been deter-mined either

33 Description of Ternary Solid Solutions

331 Homogeneity Range of Al8Mn5and Al

11Mn4 Al8Mn5

has wide homogeneity range in Al-Mn binary system How-ever it is difficult to estimate how much of Zn dissolvedin this compound from the results of DC 2 (Mn-Al

94Zn6)

Journal of Materials 11

Al8Mn5

Al11Mn4

80120583m

(a)

Al8Mn5

50120583m

(b)

20 25 30 35 40 45 50 550

100

200

300

400

500

600

Cou

nts

Position of 2120579

Al8Mn5

98 Al8Mn5

(c)

Figure 12 (a) Backscattered electron image of sample 14 (b) backscattered electron image of sample 15 (c) XRD spectrum of sample 15

Thus DC 4 (Mn-Al65Mn30Zn5) was prepared in order to

determine the homogeneity range of Al8Mn5in this ternary

system Because Al11Mn4has higher growth rate one end

member of DC 4 (Mn-Al65Mn30Zn5) has been selected near

the Al8Mn5region to increase the atomic exchange between

Al and Mn From the backscattered electron image of DC4 (Mn-Al

65Mn30Zn5) shown in Figure 11(a) Al

8Mn5formed

a thick layer and the color changed along with decreasingMn content which suggests the presence of a homogeneityrange Line-scan shown in Figure 11(b) was carried outto determine the homogeneity range of Al

8Mn5 In the

Al11Mn4+ Al8Mn5two-phase region dotted lines denote

the concentrations of elements in Al11Mn4and solid lines

represent the concentrations of elements in Al8Mn5 The

SEMEDS analysis showed that Al8Mn5has ternary solubility

of 9 at Zn and Al11Mn4has maximum ternary solubility

of 4 at Zn Al concentration in Al8Mn5layer varied from

49 at to 58 atAl11Mn4and Al

8Mn5showed extended ternary solubility

in this system at 400∘C In order to confirm the resultsobtained from previous diffusion couples four key alloys(14 to 17) were prepared The composition and phase iden-tification of these key samples are summarized in Table 2The phase relations obtained from EPMA showed greatconsistency with the XRD results Backscattered electronimage of sample 14 is shown in Figure 12(a) From EPMA

point analysis Al11Mn4has a ternary solubility of about 4 at

Zn and Al8Mn5has a maximum ternary solubility of 10 at

Zn These results were consistent with the previous EPMAobservation of samples 9 and 11 Figure 12(b) shows thatsample 15 contains mainly Al

8Mn5whose ternary solubility

was measured around 4 at Zn The XRD analysis also con-firmed that Al

8Mn5is dominating in sample 15 as shown in

Figure 12(c)There are a few unlabeled small peaks indicatingthe presence of Al

11Mn4traces which could not be identified

in the current study because of their low intensity

332 Single Region of 120576 Phase Controversy on whether120576 has three-phase separations reported in the assessmentof Okamoto and Tanner [15] is still not resolved In thecurrent study one end-member of DC 5 (Al-Mn

32Zn68)

has a composition in the 120576-phase region EPMA line-scanindicated that 120576-phase has continuous binary solubility rangesreaching fromMn

32Zn68to Mn

40Zn60at 400∘CThis finding

also corresponds to the Mn-Zn binary system which wasreported by [32 35] The backscattered electron image of DC5 (Al-Mn

32Zn68) is presented in Figure 13 Five phases have

been identified 120576 Al-rich 120573-Mn1015840 Al8Mn5 Al11Mn4 and Al-

fcc In the current experimental investigation the maximumsolubility of Zn in 120573-Mn1015840 was measured as 4 at Single 120576-phase region with the Mn content from 32 to 40 at was

12 Journal of Materials

Al8Mn5

120573-Mn998400

Al11Mn4

Al-fcc

Mn32Zn68(120576)

Figure 13 Backscattered electron image of DC 5 (Al-Mn32

Zn68

)

observed at 400∘C and nothing indicated the presence ofphase separation in this composition range From the resultsof sample 17 (Al

30Mn35Zn35) 120576-phase was found to have

limited ternary solubility of 4 at Al

34 Isothermal Section of Al-Mn-Zn System at 400∘C Com-bining the results which were obtained from the diffusioncouples with those obtained from the key alloys the Al-Mn-Zn isothermal section at 400∘C was constructed and pre-sented in Figure 14 Solid lines represent the experimentallyverified phase boundaries and ternary solubility of binaryphases Dotted lines are the estimated phase relationshipswhich were not confirmed in the current study They wereconstructed based on the Gibbs phase rule [36] and Schreine-makerrsquos rule [37] Grey blue and green areas indicate thesingle two-phase and three-phase regions separately asshown in Figure 14

4 Conclusion

The Al-Mn-Zn isothermal section at 400∘C was constructedbased on the current experimental results of diffusion coupletechnique and selected key alloys Phase relationships andsolubility limits have been determined for the ternary andbinary compounds The previously reported ternary com-pound T3 was confirmed in the current study and is denotedas 1205912in this paper Two new ternary compounds 120591

1and 1205913

have been found in this system at 400∘C 1205911does not show

significant solubility ranges and is considered stoichiometric1205913is a solid solution with a narrow homogeneity range

The formulae of the three Al-Mn-Zn ternary intermetalliccompounds are 120591

1 Al31Mn8Zn11 1205912 Al72Mn16Zn12 and 120591

3

Al119909Mn119910Zn119911(119909 = 9ndash13 at 119910 = 11ndash15 at 119911 = 75ndash77 at) A

single-phase region of Al8Mn5with extended solubility was

found in this system at 400∘C Based on the current findingsthe ternary solubilities of the Al

8Mn5 Al4Mn and Al

11Mn4

compounds have been determined as 10 at 6 at and 4 atZn respectively 120576 and Mn

5Zn21

exhibit their maximumsolubilities of 4 at and 5 at Al The solubility of Zn in120573-Mn1015840 has been found to be 4 at and 120573-Mn10158401015840 has ternarysolubility of 3 at Al

Mole

frac

tion

Al

0 20 40 60 80 100

0

20

40

60

80

100 0

20

40

60

80

100

Single-phase regionTwo-phase region

Mole fraction M

n

Zn

Mn

AlMole fraction Zn

400∘C

Al8Mn5

Al 8Mn 5

Al6MnAl4Mn

120573-Mn998400 120573-M

n998400

120573-Mn998400998400

Al11Mn4

Al12Mn MnZn13MnZn9

Mn5Zn21

120576

Three-phase region

1205912 1205911

Al-f

cc

Liqu

idZn

-HCP

120573-Mn998400 + 120573-Mn998400998400

120573-Mn 998400+ 120573-Mn 998400998400

+ 120576

Al8Mn5 + 120573- Mn998400

Al8Mn5 + 120576Al8Mn

5 + Mn5Zn

21 + 1205913

Al8Mn5 + Al11Mn4 + 12059131205911 + Al11Mn4 + 1205913

1205911 + Al-fcc + 1205913

Al8Mn5 + 120573-Mn 998400

+ 120576

Figure 14 Isothermal section of Al-Mn-Zn ternary system at 400∘Cconstructed by diffusion couples and key samples

Conflict of Interests

The authors declare that there is no conflict of interestsof any sort that might have influenced the discussions orconclusions of this paper

Acknowledgments

Financial support from General Motors of Canada Ltd andthe Natural Sciences and Engineering Research Councilof Canada (NSERC) through the CRD grant program isgratefully acknowledged The authors would also like toacknowledge the help of Mohammad Mezbahul-Islam ofMechanical Engineering Department Concordia Universityfor his valuable suggestions

References

[1] G S Cole and A M Sherman ldquoLight weight materials forautomotive applicationsrdquo Materials Characterization vol 35no 1 pp 3ndash9 1995

[2] S W Nam and B O Kong ldquoDevelopment of weldable highstrength alalloyrdquo KOSEF Technical Report 1993

[3] H S Cho and S W Nam ldquoA study of the low cycle fatigueproperties of weldable Al-Zn-Mg-Mn Alloy and Al 7039 invarious environmentsrdquo Journal of Korean Institute of Metals andMaterials vol 32 no 7 pp 765ndash770 1994

[4] M Ohno D Mirkovic and R Schmid-Fetzer ldquoLiquidus andsolidus temperatures of Mg-rich Mg-Al-Mn-Zn alloysrdquo ActaMaterialia vol 54 no 15 pp 3883ndash3891 2006

[5] N Gao Y H Liu and N-Y Tang ldquoAn experimental study ofthe liquid domain of the Zn-Fe-Al-Mn quaternary system at

Journal of Materials 13

460∘Crdquo Journal of Phase Equilibria and Diffusion vol 31 no 6pp 523ndash531 2010

[6] M A Khan and M Medraj ldquoThermodynamic descriptionof the Mg-Mn Al-Mn and Mg-Al-Mn systems using themodified quasichemical model for the liquid phasesrdquoMaterialsTransactions vol 50 no 5 pp 1113ndash1122 2009

[7] C Muller H Stadelmaier B Reinsch and G Petzow ldquoMet-allurgy of the magnetic 120591-phase in Mn-Al and Mn-Al-CrdquoZeitschrift fuer Metallkunde vol 87 no 7 pp 594ndash597 1996

[8] A Shukla and A D Pelton ldquoThermodynamic assessment of theAl-Mn andMg-Al-Mn systemsrdquo Journal of Phase Equilibria andDiffusion vol 30 no 1 pp 28ndash39 2009

[9] H Kono ldquoOn the ferromagnetic phase in manganese-aluminum systemrdquo Journal of the Physical Society of Japan vol13 no 12 pp 1444ndash1451 1958

[10] W Koster and E Wachtel ldquoConstitution and magnetic proper-ties of aluminum-manganese alloyswithmore than 5AtMnrdquoZeitschrift fuer Metallkunde vol 51 pp 271ndash280 1960

[11] Y Minamino T Yamane H Araki et al ldquoSolid solubilities ofmanganese and titanium in aluminum at 01 MPa and 21 GPardquoMetallurgical Transactions A vol 22 no 3 pp 783ndash786 1991

[12] H Okamoto ldquoAl-Mn (Aluminum-Manganese)rdquo Journal ofPhase Equilibria vol 18 no 4 pp 398ndash399 1997

[13] M A Taylor ldquoIntermetallig phases in the aluminiumman-ganese binary systemrdquo Acta Metallurgica vol 8 no 4 pp 256ndash262 1960

[14] S Wasiur-Rahman andMMedraj ldquoA thermodynamic descrip-tion of the Al-Ca-Zn ternary systemrdquoCalphad vol 33 no 3 pp584ndash598 2009

[15] H Okamoto and L E Tanner ldquoThe Mn-Zn (Manganese-Zinc)systemrdquo Bulletin of Alloy Phase Diagrams vol 11 no 4 pp 377ndash384 1990

[16] S Tezuka S Sakai and Y Nakagawa ldquoFerromagnetism of Mn-Zn alloyrdquo Journal of the Physical Society of Japan vol 15 no 5p 931 1960

[17] Y Nakagawa and T Hori ldquoMagnetic transition and crystaldistortion in MnHg andMnZn

3

rdquo Journal of the Physical Societyof Japan vol 17 no 8 pp 1313ndash1314 1962

[18] B Henderson and R J M Willcox ldquoLattice spacing relation-ships in hexagonal close-packed Silver-Zinc-Manganese alloysrdquoPhilosophical Magazine vol 9 no 101 pp 829ndash846 1964

[19] R A Farrar and H W King ldquoAxial ratios and solubility limitsof HCP 120578 and 120576 phases in the systems CdMn and ZnMnrdquoMetallography vol 3 no 1 pp 61ndash70 1970

[20] J L Liang Y Du C Z Liao et al ldquoExperimental investigationon the phase equilibria of the Mn-Ni-Zn system at 400∘CrdquoJournal of Alloys and Compounds vol 489 no 2 pp 362ndash3682010

[21] J L Liang Y Du Q Z Zhao et al ldquoDetermination of the phaseequilibria in the Mn-Sn-Zn system at 500∘ Crdquo MetallurgicalandMaterials Transactions A PhysicalMetallurgy andMaterialsScience vol 40 no 12 pp 2909ndash2918 2009

[22] H Xu X Xiong L Zhang YDu and PWang ldquoPhase equilibriaof the Mn-Si-Zn system at 600∘Crdquo Metallurgical and MaterialsTransactions A Physical Metallurgy and Materials Science vol40 no 9 pp 2042ndash2047 2009

[23] E Gebhardt ldquoDie zinkecke des dreistoffsystems zink-aluminium-manganrdquo Zeitschrift fur Metallkunde vol 34pp 259ndash263 1942

[24] G V Raynor and D W Wakeman ldquoThe intermetallic com-pound phases of the system Aluminium-Manganese-Zincrdquo

Proceedings of the Royal Society of London A Mathematical andPhysical Sciences vol 190 no 1020 pp 82ndash101 1947

[25] K Robinson ldquoThe determination of the crystal structure ofNi4

Mn11

Al60

rdquo Acta Crystallographica vol 7 part 6-7 pp 494ndash497 1954

[26] A Damjanovic ldquoThe structure analysis of the T3

(A1MnZn)compoundrdquo Acta Crystallographica vol 14 pp 982ndash987 1961

[27] R J Schaefer L A Bendersky D Shechtman W J Boettingerand F S Biancaniello ldquoIcosahedral and decagonal phase forma-tion in Al-Mn Alloysrdquo Metallurgical transactions A vol 17 no12 pp 2117ndash2125 1986

[28] A Singh S Ranganathan and L A Bendersky ldquoQuasicrys-talline phases and their approximants inAl-Mn-Zn alloysrdquoActaMaterialia vol 45 no 12 pp 5327ndash5336 1997

[29] J S Kirkaldy and L C Brown ldquoDiffusion behavior in theternarymultiphase systemsrdquoCanadianMetallurgicalQuarterlyvol 2 no 1 pp 90ndash115 1963

[30] J B Clark ldquoConventions for plotting the diffusion paths inmultiphase ternary diffusion couples on the isothermal sectionof a ternary phase diagramrdquo Transactions of the MetallurgicalSociety of AIME vol 227 pp 1250ndash1251 1963

[31] A A Kodentsov G F Bastin and F J J van Loo ldquoThe diffusioncouple technique in phase diagram determinationrdquo Journal ofAlloys and Compounds vol 320 no 2 pp 207ndash217 2001

[32] M A Khan Thermodynamic modeling of the MgndashMnndash(Al Zn)systems [MS thesis] Concordia University 2009

[33] PANalytical Ver22b (222) PANalytical Almelo The Nether-lands 2006

[34] H Putz and K Brandenburg Pearsonrsquos Crystal Data CrystalStructure Database for Inorganic Compounds CD-ROM Soft-ware Version 13

[35] P Ghosh and M Medraj ldquoThermodynamic calculation of theMg-Mn-Zn and Mg-Mn-Ce systems and re-optimization oftheir constitutive binariesrdquo Calphad Computer Coupling ofPhase Diagrams andThermochemistry vol 41 pp 89ndash107 2013

[36] A Prince Alloy Phase Equilibria Elsevier Amsterdam TheNetherland 1966

[37] L Y H John ldquoSchreinemakers rule as applied to non-degenerate ternary systemsrdquoThe Journal of Young Investigatorsvol 19 no 11 2009

Submit your manuscripts athttpwwwhindawicom

ScientificaHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CorrosionInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Polymer ScienceInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CeramicsJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CompositesJournal of

NanoparticlesJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

International Journal of

Biomaterials

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

NanoscienceJournal of

TextilesHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Journal of

NanotechnologyHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

CrystallographyJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CoatingsJournal of

Advances in

Materials Science and EngineeringHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Smart Materials Research

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

MetallurgyJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

BioMed Research International

MaterialsJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Nano

materials

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal ofNanomaterials

Journal of Materials 9

30 35 40 45 50 55 60 65 70 75 800

50

100

150

200

250

300

350C

ount

s

Position of 2120579

(a)

30 35 40 45 50 55 60 65 70 75 800

50

100

150

200

250

300

350

Cou

nts

Position of 2120579

(b)

30 35 40 45 50 55 60 65 70 75 800

50

100

150

200

250

300

Cou

nts

SiAl

Position of 2120579

Al4Mn1205912

(c)

Figure 10 (a) XRD spectrum of annealed sample 2 (b) XRD spectrum of annealed sample 3 (c) XRD spectrum of annealed sample 5

the homogeneity range of Al4Mn which indicated that T1

might be a quasicrystal of Al4Mnwith extended Zn solubility

1205913was observed in DC 3 (Al-Mn

13Zn87) and the com-

position was primarily determined as Al10Mn15Zn75 Several

key alloys were prepared to study this new compound Theactual compositions of these samples and the compositionsof the detected phases are listed in Table 2 The 120591

3phase has

a complex homogeneity range 9ndash13 at Al 11ndash15 at Mnand 75ndash77 at Zn as was determined by the analysis of DC3 (Al-Mn

13Zn87) and key samples 9 to 13 Sample 9 is an

example of these findings as shown in Figures 8(a) and 8(b)The sample contains residuals of the primary Al

8Mn5phase

that decomposes according to the peritectic reaction L+Al8Mn5rarr Al

11Mn4 The decomposition of Al

8Mn5was not

complete due to the slow kinetics of the peritectic reaction 1205913

phase formed a matrix in this alloyThe homogeneity ranges of the binary compounds were

determined using EPMA From the EPMA results Al11Mn4

exhibited ternary solubility reaching up to 4 at Zn Al4Mn

had the maximum ternary solubility of 6 at Zn Thedissolved Zn in Al-fcc was found to reach up to 45 atTernary homogeneity range of Al

8Mn5has been determined

by EPMA as 11 atZnThese observations also confirmed theresults which were inferred from DC 4 (Mn-Al

65Mn30Zn5)

Additionally another ternary phase 1205914was found in this

ternary system The composition of this phase is in the

region around Al23Mn16Zn61 However 120591

4is found to be

metastable As shown in Figure 8(c) three phases Al11Mn4

1205913 and 120591

4were found in sample 12 to be annealed at 400∘C

for 25 days After prolonged annealing for another 15 days 1205914

decomposed to provide more 1205913and Al

11Mn4

In order to verify the observations of the ternary com-pounds key alloys were studied using XRD The XRDpatterns of sample 1 are illustrated in Figure 9 Al-fcc andAl4Mn are positively identified in the XRD pattern Besides

there are several peaks which do not belong to any of theknown binary phases in the system Based on the resultsof phase identifications those peaks could correspond to1205911 Because of the lack of the reported prototype of 120591

1 the

peaks which belong to 1205911were hard to separate due to the

several overlapping peaks in the XRD pattern of this sampleThus the crystal structure of this compound could not bedetermined in the current study However the peaks whichcould belong to 120591

1have been labeled as shown in Figure 9

T3 phase reported by [24] denoted as 1205912in the current

study was confirmed through XRD analysis Three XRDspectra of sample 2 3 and 5 were used for this purpose Asshown in Figure 10 the XRD patterns of the three samplesare similar From 2120579 position 40∘ to 45∘ hump-like patternscan be observed due to peaks overlapping This is becauseAl4Mnhas very complex crystal structure and has around 550

atoms in a giant unit cell [34] During the X-ray scanning

10 Journal of Materials

Mn

Al8Mn5Al8Mn5

120573-Mn998400

Al11Mn4

50120583m

(a)

0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 340

10

20

30

40

50

60

70

80

90

100

Elem

ents

(at

)

Points number

MnZn

AlAl8Mn5

Al8Mn5120573-Mn998400

Al11Mn4

Al8Mn5

Al11Mn4

(b)

Figure 11 (a) Backscattered electron image of diffusion couple DC 4 (Mn-Al65

Mn30

Zn5

) (b) composition profile of line-scan in diffusioncouple DC 4 (Mn-Al

65

Mn30

Zn5

)

process the diffracted spectra of Al4Mn were overlapping

with other peaks at numerous positions and generate theseoverlapped patterns Using the crystallographic entry of T3from Pearsonrsquos database [34] T3 was positively identifiedamong XRD analysis Along with Al-fcc and Al

4Mn the

triangulation among those three phases was establishedXRD analysis of ternary compound 120591

3has similar issues

to 1205911as elucidated above Unfortunately too many peaks

were overlapping in a multiphase alloy and a single-phasesample representing 120591

3was not possible to prepareTherefore

the crystal structure of this compound has not been deter-mined either

33 Description of Ternary Solid Solutions

331 Homogeneity Range of Al8Mn5and Al

11Mn4 Al8Mn5

has wide homogeneity range in Al-Mn binary system How-ever it is difficult to estimate how much of Zn dissolvedin this compound from the results of DC 2 (Mn-Al

94Zn6)

Journal of Materials 11

Al8Mn5

Al11Mn4

80120583m

(a)

Al8Mn5

50120583m

(b)

20 25 30 35 40 45 50 550

100

200

300

400

500

600

Cou

nts

Position of 2120579

Al8Mn5

98 Al8Mn5

(c)

Figure 12 (a) Backscattered electron image of sample 14 (b) backscattered electron image of sample 15 (c) XRD spectrum of sample 15

Thus DC 4 (Mn-Al65Mn30Zn5) was prepared in order to

determine the homogeneity range of Al8Mn5in this ternary

system Because Al11Mn4has higher growth rate one end

member of DC 4 (Mn-Al65Mn30Zn5) has been selected near

the Al8Mn5region to increase the atomic exchange between

Al and Mn From the backscattered electron image of DC4 (Mn-Al

65Mn30Zn5) shown in Figure 11(a) Al

8Mn5formed

a thick layer and the color changed along with decreasingMn content which suggests the presence of a homogeneityrange Line-scan shown in Figure 11(b) was carried outto determine the homogeneity range of Al

8Mn5 In the

Al11Mn4+ Al8Mn5two-phase region dotted lines denote

the concentrations of elements in Al11Mn4and solid lines

represent the concentrations of elements in Al8Mn5 The

SEMEDS analysis showed that Al8Mn5has ternary solubility

of 9 at Zn and Al11Mn4has maximum ternary solubility

of 4 at Zn Al concentration in Al8Mn5layer varied from

49 at to 58 atAl11Mn4and Al

8Mn5showed extended ternary solubility

in this system at 400∘C In order to confirm the resultsobtained from previous diffusion couples four key alloys(14 to 17) were prepared The composition and phase iden-tification of these key samples are summarized in Table 2The phase relations obtained from EPMA showed greatconsistency with the XRD results Backscattered electronimage of sample 14 is shown in Figure 12(a) From EPMA

point analysis Al11Mn4has a ternary solubility of about 4 at

Zn and Al8Mn5has a maximum ternary solubility of 10 at

Zn These results were consistent with the previous EPMAobservation of samples 9 and 11 Figure 12(b) shows thatsample 15 contains mainly Al

8Mn5whose ternary solubility

was measured around 4 at Zn The XRD analysis also con-firmed that Al

8Mn5is dominating in sample 15 as shown in

Figure 12(c)There are a few unlabeled small peaks indicatingthe presence of Al

11Mn4traces which could not be identified

in the current study because of their low intensity

332 Single Region of 120576 Phase Controversy on whether120576 has three-phase separations reported in the assessmentof Okamoto and Tanner [15] is still not resolved In thecurrent study one end-member of DC 5 (Al-Mn

32Zn68)

has a composition in the 120576-phase region EPMA line-scanindicated that 120576-phase has continuous binary solubility rangesreaching fromMn

32Zn68to Mn

40Zn60at 400∘CThis finding

also corresponds to the Mn-Zn binary system which wasreported by [32 35] The backscattered electron image of DC5 (Al-Mn

32Zn68) is presented in Figure 13 Five phases have

been identified 120576 Al-rich 120573-Mn1015840 Al8Mn5 Al11Mn4 and Al-

fcc In the current experimental investigation the maximumsolubility of Zn in 120573-Mn1015840 was measured as 4 at Single 120576-phase region with the Mn content from 32 to 40 at was

12 Journal of Materials

Al8Mn5

120573-Mn998400

Al11Mn4

Al-fcc

Mn32Zn68(120576)

Figure 13 Backscattered electron image of DC 5 (Al-Mn32

Zn68

)

observed at 400∘C and nothing indicated the presence ofphase separation in this composition range From the resultsof sample 17 (Al

30Mn35Zn35) 120576-phase was found to have

limited ternary solubility of 4 at Al

34 Isothermal Section of Al-Mn-Zn System at 400∘C Com-bining the results which were obtained from the diffusioncouples with those obtained from the key alloys the Al-Mn-Zn isothermal section at 400∘C was constructed and pre-sented in Figure 14 Solid lines represent the experimentallyverified phase boundaries and ternary solubility of binaryphases Dotted lines are the estimated phase relationshipswhich were not confirmed in the current study They wereconstructed based on the Gibbs phase rule [36] and Schreine-makerrsquos rule [37] Grey blue and green areas indicate thesingle two-phase and three-phase regions separately asshown in Figure 14

4 Conclusion

The Al-Mn-Zn isothermal section at 400∘C was constructedbased on the current experimental results of diffusion coupletechnique and selected key alloys Phase relationships andsolubility limits have been determined for the ternary andbinary compounds The previously reported ternary com-pound T3 was confirmed in the current study and is denotedas 1205912in this paper Two new ternary compounds 120591

1and 1205913

have been found in this system at 400∘C 1205911does not show

significant solubility ranges and is considered stoichiometric1205913is a solid solution with a narrow homogeneity range

The formulae of the three Al-Mn-Zn ternary intermetalliccompounds are 120591

1 Al31Mn8Zn11 1205912 Al72Mn16Zn12 and 120591

3

Al119909Mn119910Zn119911(119909 = 9ndash13 at 119910 = 11ndash15 at 119911 = 75ndash77 at) A

single-phase region of Al8Mn5with extended solubility was

found in this system at 400∘C Based on the current findingsthe ternary solubilities of the Al

8Mn5 Al4Mn and Al

11Mn4

compounds have been determined as 10 at 6 at and 4 atZn respectively 120576 and Mn

5Zn21

exhibit their maximumsolubilities of 4 at and 5 at Al The solubility of Zn in120573-Mn1015840 has been found to be 4 at and 120573-Mn10158401015840 has ternarysolubility of 3 at Al

Mole

frac

tion

Al

0 20 40 60 80 100

0

20

40

60

80

100 0

20

40

60

80

100

Single-phase regionTwo-phase region

Mole fraction M

n

Zn

Mn

AlMole fraction Zn

400∘C

Al8Mn5

Al 8Mn 5

Al6MnAl4Mn

120573-Mn998400 120573-M

n998400

120573-Mn998400998400

Al11Mn4

Al12Mn MnZn13MnZn9

Mn5Zn21

120576

Three-phase region

1205912 1205911

Al-f

cc

Liqu

idZn

-HCP

120573-Mn998400 + 120573-Mn998400998400

120573-Mn 998400+ 120573-Mn 998400998400

+ 120576

Al8Mn5 + 120573- Mn998400

Al8Mn5 + 120576Al8Mn

5 + Mn5Zn

21 + 1205913

Al8Mn5 + Al11Mn4 + 12059131205911 + Al11Mn4 + 1205913

1205911 + Al-fcc + 1205913

Al8Mn5 + 120573-Mn 998400

+ 120576

Figure 14 Isothermal section of Al-Mn-Zn ternary system at 400∘Cconstructed by diffusion couples and key samples

Conflict of Interests

The authors declare that there is no conflict of interestsof any sort that might have influenced the discussions orconclusions of this paper

Acknowledgments

Financial support from General Motors of Canada Ltd andthe Natural Sciences and Engineering Research Councilof Canada (NSERC) through the CRD grant program isgratefully acknowledged The authors would also like toacknowledge the help of Mohammad Mezbahul-Islam ofMechanical Engineering Department Concordia Universityfor his valuable suggestions

References

[1] G S Cole and A M Sherman ldquoLight weight materials forautomotive applicationsrdquo Materials Characterization vol 35no 1 pp 3ndash9 1995

[2] S W Nam and B O Kong ldquoDevelopment of weldable highstrength alalloyrdquo KOSEF Technical Report 1993

[3] H S Cho and S W Nam ldquoA study of the low cycle fatigueproperties of weldable Al-Zn-Mg-Mn Alloy and Al 7039 invarious environmentsrdquo Journal of Korean Institute of Metals andMaterials vol 32 no 7 pp 765ndash770 1994

[4] M Ohno D Mirkovic and R Schmid-Fetzer ldquoLiquidus andsolidus temperatures of Mg-rich Mg-Al-Mn-Zn alloysrdquo ActaMaterialia vol 54 no 15 pp 3883ndash3891 2006

[5] N Gao Y H Liu and N-Y Tang ldquoAn experimental study ofthe liquid domain of the Zn-Fe-Al-Mn quaternary system at

Journal of Materials 13

460∘Crdquo Journal of Phase Equilibria and Diffusion vol 31 no 6pp 523ndash531 2010

[6] M A Khan and M Medraj ldquoThermodynamic descriptionof the Mg-Mn Al-Mn and Mg-Al-Mn systems using themodified quasichemical model for the liquid phasesrdquoMaterialsTransactions vol 50 no 5 pp 1113ndash1122 2009

[7] C Muller H Stadelmaier B Reinsch and G Petzow ldquoMet-allurgy of the magnetic 120591-phase in Mn-Al and Mn-Al-CrdquoZeitschrift fuer Metallkunde vol 87 no 7 pp 594ndash597 1996

[8] A Shukla and A D Pelton ldquoThermodynamic assessment of theAl-Mn andMg-Al-Mn systemsrdquo Journal of Phase Equilibria andDiffusion vol 30 no 1 pp 28ndash39 2009

[9] H Kono ldquoOn the ferromagnetic phase in manganese-aluminum systemrdquo Journal of the Physical Society of Japan vol13 no 12 pp 1444ndash1451 1958

[10] W Koster and E Wachtel ldquoConstitution and magnetic proper-ties of aluminum-manganese alloyswithmore than 5AtMnrdquoZeitschrift fuer Metallkunde vol 51 pp 271ndash280 1960

[11] Y Minamino T Yamane H Araki et al ldquoSolid solubilities ofmanganese and titanium in aluminum at 01 MPa and 21 GPardquoMetallurgical Transactions A vol 22 no 3 pp 783ndash786 1991

[12] H Okamoto ldquoAl-Mn (Aluminum-Manganese)rdquo Journal ofPhase Equilibria vol 18 no 4 pp 398ndash399 1997

[13] M A Taylor ldquoIntermetallig phases in the aluminiumman-ganese binary systemrdquo Acta Metallurgica vol 8 no 4 pp 256ndash262 1960

[14] S Wasiur-Rahman andMMedraj ldquoA thermodynamic descrip-tion of the Al-Ca-Zn ternary systemrdquoCalphad vol 33 no 3 pp584ndash598 2009

[15] H Okamoto and L E Tanner ldquoThe Mn-Zn (Manganese-Zinc)systemrdquo Bulletin of Alloy Phase Diagrams vol 11 no 4 pp 377ndash384 1990

[16] S Tezuka S Sakai and Y Nakagawa ldquoFerromagnetism of Mn-Zn alloyrdquo Journal of the Physical Society of Japan vol 15 no 5p 931 1960

[17] Y Nakagawa and T Hori ldquoMagnetic transition and crystaldistortion in MnHg andMnZn

3

rdquo Journal of the Physical Societyof Japan vol 17 no 8 pp 1313ndash1314 1962

[18] B Henderson and R J M Willcox ldquoLattice spacing relation-ships in hexagonal close-packed Silver-Zinc-Manganese alloysrdquoPhilosophical Magazine vol 9 no 101 pp 829ndash846 1964

[19] R A Farrar and H W King ldquoAxial ratios and solubility limitsof HCP 120578 and 120576 phases in the systems CdMn and ZnMnrdquoMetallography vol 3 no 1 pp 61ndash70 1970

[20] J L Liang Y Du C Z Liao et al ldquoExperimental investigationon the phase equilibria of the Mn-Ni-Zn system at 400∘CrdquoJournal of Alloys and Compounds vol 489 no 2 pp 362ndash3682010

[21] J L Liang Y Du Q Z Zhao et al ldquoDetermination of the phaseequilibria in the Mn-Sn-Zn system at 500∘ Crdquo MetallurgicalandMaterials Transactions A PhysicalMetallurgy andMaterialsScience vol 40 no 12 pp 2909ndash2918 2009

[22] H Xu X Xiong L Zhang YDu and PWang ldquoPhase equilibriaof the Mn-Si-Zn system at 600∘Crdquo Metallurgical and MaterialsTransactions A Physical Metallurgy and Materials Science vol40 no 9 pp 2042ndash2047 2009

[23] E Gebhardt ldquoDie zinkecke des dreistoffsystems zink-aluminium-manganrdquo Zeitschrift fur Metallkunde vol 34pp 259ndash263 1942

[24] G V Raynor and D W Wakeman ldquoThe intermetallic com-pound phases of the system Aluminium-Manganese-Zincrdquo

Proceedings of the Royal Society of London A Mathematical andPhysical Sciences vol 190 no 1020 pp 82ndash101 1947

[25] K Robinson ldquoThe determination of the crystal structure ofNi4

Mn11

Al60

rdquo Acta Crystallographica vol 7 part 6-7 pp 494ndash497 1954

[26] A Damjanovic ldquoThe structure analysis of the T3

(A1MnZn)compoundrdquo Acta Crystallographica vol 14 pp 982ndash987 1961

[27] R J Schaefer L A Bendersky D Shechtman W J Boettingerand F S Biancaniello ldquoIcosahedral and decagonal phase forma-tion in Al-Mn Alloysrdquo Metallurgical transactions A vol 17 no12 pp 2117ndash2125 1986

[28] A Singh S Ranganathan and L A Bendersky ldquoQuasicrys-talline phases and their approximants inAl-Mn-Zn alloysrdquoActaMaterialia vol 45 no 12 pp 5327ndash5336 1997

[29] J S Kirkaldy and L C Brown ldquoDiffusion behavior in theternarymultiphase systemsrdquoCanadianMetallurgicalQuarterlyvol 2 no 1 pp 90ndash115 1963

[30] J B Clark ldquoConventions for plotting the diffusion paths inmultiphase ternary diffusion couples on the isothermal sectionof a ternary phase diagramrdquo Transactions of the MetallurgicalSociety of AIME vol 227 pp 1250ndash1251 1963

[31] A A Kodentsov G F Bastin and F J J van Loo ldquoThe diffusioncouple technique in phase diagram determinationrdquo Journal ofAlloys and Compounds vol 320 no 2 pp 207ndash217 2001

[32] M A Khan Thermodynamic modeling of the MgndashMnndash(Al Zn)systems [MS thesis] Concordia University 2009

[33] PANalytical Ver22b (222) PANalytical Almelo The Nether-lands 2006

[34] H Putz and K Brandenburg Pearsonrsquos Crystal Data CrystalStructure Database for Inorganic Compounds CD-ROM Soft-ware Version 13

[35] P Ghosh and M Medraj ldquoThermodynamic calculation of theMg-Mn-Zn and Mg-Mn-Ce systems and re-optimization oftheir constitutive binariesrdquo Calphad Computer Coupling ofPhase Diagrams andThermochemistry vol 41 pp 89ndash107 2013

[36] A Prince Alloy Phase Equilibria Elsevier Amsterdam TheNetherland 1966

[37] L Y H John ldquoSchreinemakers rule as applied to non-degenerate ternary systemsrdquoThe Journal of Young Investigatorsvol 19 no 11 2009

Submit your manuscripts athttpwwwhindawicom

ScientificaHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CorrosionInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Polymer ScienceInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CeramicsJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CompositesJournal of

NanoparticlesJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

International Journal of

Biomaterials

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

NanoscienceJournal of

TextilesHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Journal of

NanotechnologyHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

CrystallographyJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CoatingsJournal of

Advances in

Materials Science and EngineeringHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Smart Materials Research

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

MetallurgyJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

BioMed Research International

MaterialsJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Nano

materials

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal ofNanomaterials

10 Journal of Materials

Mn

Al8Mn5Al8Mn5

120573-Mn998400

Al11Mn4

50120583m

(a)

0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 340

10

20

30

40

50

60

70

80

90

100

Elem

ents

(at

)

Points number

MnZn

AlAl8Mn5

Al8Mn5120573-Mn998400

Al11Mn4

Al8Mn5

Al11Mn4

(b)

Figure 11 (a) Backscattered electron image of diffusion couple DC 4 (Mn-Al65

Mn30

Zn5

) (b) composition profile of line-scan in diffusioncouple DC 4 (Mn-Al

65

Mn30

Zn5

)

process the diffracted spectra of Al4Mn were overlapping

with other peaks at numerous positions and generate theseoverlapped patterns Using the crystallographic entry of T3from Pearsonrsquos database [34] T3 was positively identifiedamong XRD analysis Along with Al-fcc and Al

4Mn the

triangulation among those three phases was establishedXRD analysis of ternary compound 120591

3has similar issues

to 1205911as elucidated above Unfortunately too many peaks

were overlapping in a multiphase alloy and a single-phasesample representing 120591

3was not possible to prepareTherefore

the crystal structure of this compound has not been deter-mined either

33 Description of Ternary Solid Solutions

331 Homogeneity Range of Al8Mn5and Al

11Mn4 Al8Mn5

has wide homogeneity range in Al-Mn binary system How-ever it is difficult to estimate how much of Zn dissolvedin this compound from the results of DC 2 (Mn-Al

94Zn6)

Journal of Materials 11

Al8Mn5

Al11Mn4

80120583m

(a)

Al8Mn5

50120583m

(b)

20 25 30 35 40 45 50 550

100

200

300

400

500

600

Cou

nts

Position of 2120579

Al8Mn5

98 Al8Mn5

(c)

Figure 12 (a) Backscattered electron image of sample 14 (b) backscattered electron image of sample 15 (c) XRD spectrum of sample 15

Thus DC 4 (Mn-Al65Mn30Zn5) was prepared in order to

determine the homogeneity range of Al8Mn5in this ternary

system Because Al11Mn4has higher growth rate one end

member of DC 4 (Mn-Al65Mn30Zn5) has been selected near

the Al8Mn5region to increase the atomic exchange between

Al and Mn From the backscattered electron image of DC4 (Mn-Al

65Mn30Zn5) shown in Figure 11(a) Al

8Mn5formed

a thick layer and the color changed along with decreasingMn content which suggests the presence of a homogeneityrange Line-scan shown in Figure 11(b) was carried outto determine the homogeneity range of Al

8Mn5 In the

Al11Mn4+ Al8Mn5two-phase region dotted lines denote

the concentrations of elements in Al11Mn4and solid lines

represent the concentrations of elements in Al8Mn5 The

SEMEDS analysis showed that Al8Mn5has ternary solubility

of 9 at Zn and Al11Mn4has maximum ternary solubility

of 4 at Zn Al concentration in Al8Mn5layer varied from

49 at to 58 atAl11Mn4and Al

8Mn5showed extended ternary solubility

in this system at 400∘C In order to confirm the resultsobtained from previous diffusion couples four key alloys(14 to 17) were prepared The composition and phase iden-tification of these key samples are summarized in Table 2The phase relations obtained from EPMA showed greatconsistency with the XRD results Backscattered electronimage of sample 14 is shown in Figure 12(a) From EPMA

point analysis Al11Mn4has a ternary solubility of about 4 at

Zn and Al8Mn5has a maximum ternary solubility of 10 at

Zn These results were consistent with the previous EPMAobservation of samples 9 and 11 Figure 12(b) shows thatsample 15 contains mainly Al

8Mn5whose ternary solubility

was measured around 4 at Zn The XRD analysis also con-firmed that Al

8Mn5is dominating in sample 15 as shown in

Figure 12(c)There are a few unlabeled small peaks indicatingthe presence of Al

11Mn4traces which could not be identified

in the current study because of their low intensity

332 Single Region of 120576 Phase Controversy on whether120576 has three-phase separations reported in the assessmentof Okamoto and Tanner [15] is still not resolved In thecurrent study one end-member of DC 5 (Al-Mn

32Zn68)

has a composition in the 120576-phase region EPMA line-scanindicated that 120576-phase has continuous binary solubility rangesreaching fromMn

32Zn68to Mn

40Zn60at 400∘CThis finding

also corresponds to the Mn-Zn binary system which wasreported by [32 35] The backscattered electron image of DC5 (Al-Mn

32Zn68) is presented in Figure 13 Five phases have

been identified 120576 Al-rich 120573-Mn1015840 Al8Mn5 Al11Mn4 and Al-

fcc In the current experimental investigation the maximumsolubility of Zn in 120573-Mn1015840 was measured as 4 at Single 120576-phase region with the Mn content from 32 to 40 at was

12 Journal of Materials

Al8Mn5

120573-Mn998400

Al11Mn4

Al-fcc

Mn32Zn68(120576)

Figure 13 Backscattered electron image of DC 5 (Al-Mn32

Zn68

)

observed at 400∘C and nothing indicated the presence ofphase separation in this composition range From the resultsof sample 17 (Al

30Mn35Zn35) 120576-phase was found to have

limited ternary solubility of 4 at Al

34 Isothermal Section of Al-Mn-Zn System at 400∘C Com-bining the results which were obtained from the diffusioncouples with those obtained from the key alloys the Al-Mn-Zn isothermal section at 400∘C was constructed and pre-sented in Figure 14 Solid lines represent the experimentallyverified phase boundaries and ternary solubility of binaryphases Dotted lines are the estimated phase relationshipswhich were not confirmed in the current study They wereconstructed based on the Gibbs phase rule [36] and Schreine-makerrsquos rule [37] Grey blue and green areas indicate thesingle two-phase and three-phase regions separately asshown in Figure 14

4 Conclusion

The Al-Mn-Zn isothermal section at 400∘C was constructedbased on the current experimental results of diffusion coupletechnique and selected key alloys Phase relationships andsolubility limits have been determined for the ternary andbinary compounds The previously reported ternary com-pound T3 was confirmed in the current study and is denotedas 1205912in this paper Two new ternary compounds 120591

1and 1205913

have been found in this system at 400∘C 1205911does not show

significant solubility ranges and is considered stoichiometric1205913is a solid solution with a narrow homogeneity range

The formulae of the three Al-Mn-Zn ternary intermetalliccompounds are 120591

1 Al31Mn8Zn11 1205912 Al72Mn16Zn12 and 120591

3

Al119909Mn119910Zn119911(119909 = 9ndash13 at 119910 = 11ndash15 at 119911 = 75ndash77 at) A

single-phase region of Al8Mn5with extended solubility was

found in this system at 400∘C Based on the current findingsthe ternary solubilities of the Al

8Mn5 Al4Mn and Al

11Mn4

compounds have been determined as 10 at 6 at and 4 atZn respectively 120576 and Mn

5Zn21

exhibit their maximumsolubilities of 4 at and 5 at Al The solubility of Zn in120573-Mn1015840 has been found to be 4 at and 120573-Mn10158401015840 has ternarysolubility of 3 at Al

Mole

frac

tion

Al

0 20 40 60 80 100

0

20

40

60

80

100 0

20

40

60

80

100

Single-phase regionTwo-phase region

Mole fraction M

n

Zn

Mn

AlMole fraction Zn

400∘C

Al8Mn5

Al 8Mn 5

Al6MnAl4Mn

120573-Mn998400 120573-M

n998400

120573-Mn998400998400

Al11Mn4

Al12Mn MnZn13MnZn9

Mn5Zn21

120576

Three-phase region

1205912 1205911

Al-f

cc

Liqu

idZn

-HCP

120573-Mn998400 + 120573-Mn998400998400

120573-Mn 998400+ 120573-Mn 998400998400

+ 120576

Al8Mn5 + 120573- Mn998400

Al8Mn5 + 120576Al8Mn

5 + Mn5Zn

21 + 1205913

Al8Mn5 + Al11Mn4 + 12059131205911 + Al11Mn4 + 1205913

1205911 + Al-fcc + 1205913

Al8Mn5 + 120573-Mn 998400

+ 120576

Figure 14 Isothermal section of Al-Mn-Zn ternary system at 400∘Cconstructed by diffusion couples and key samples

Conflict of Interests

The authors declare that there is no conflict of interestsof any sort that might have influenced the discussions orconclusions of this paper

Acknowledgments

Financial support from General Motors of Canada Ltd andthe Natural Sciences and Engineering Research Councilof Canada (NSERC) through the CRD grant program isgratefully acknowledged The authors would also like toacknowledge the help of Mohammad Mezbahul-Islam ofMechanical Engineering Department Concordia Universityfor his valuable suggestions

References

[1] G S Cole and A M Sherman ldquoLight weight materials forautomotive applicationsrdquo Materials Characterization vol 35no 1 pp 3ndash9 1995

[2] S W Nam and B O Kong ldquoDevelopment of weldable highstrength alalloyrdquo KOSEF Technical Report 1993

[3] H S Cho and S W Nam ldquoA study of the low cycle fatigueproperties of weldable Al-Zn-Mg-Mn Alloy and Al 7039 invarious environmentsrdquo Journal of Korean Institute of Metals andMaterials vol 32 no 7 pp 765ndash770 1994

[4] M Ohno D Mirkovic and R Schmid-Fetzer ldquoLiquidus andsolidus temperatures of Mg-rich Mg-Al-Mn-Zn alloysrdquo ActaMaterialia vol 54 no 15 pp 3883ndash3891 2006

[5] N Gao Y H Liu and N-Y Tang ldquoAn experimental study ofthe liquid domain of the Zn-Fe-Al-Mn quaternary system at

Journal of Materials 13

460∘Crdquo Journal of Phase Equilibria and Diffusion vol 31 no 6pp 523ndash531 2010

[6] M A Khan and M Medraj ldquoThermodynamic descriptionof the Mg-Mn Al-Mn and Mg-Al-Mn systems using themodified quasichemical model for the liquid phasesrdquoMaterialsTransactions vol 50 no 5 pp 1113ndash1122 2009

[7] C Muller H Stadelmaier B Reinsch and G Petzow ldquoMet-allurgy of the magnetic 120591-phase in Mn-Al and Mn-Al-CrdquoZeitschrift fuer Metallkunde vol 87 no 7 pp 594ndash597 1996

[8] A Shukla and A D Pelton ldquoThermodynamic assessment of theAl-Mn andMg-Al-Mn systemsrdquo Journal of Phase Equilibria andDiffusion vol 30 no 1 pp 28ndash39 2009

[9] H Kono ldquoOn the ferromagnetic phase in manganese-aluminum systemrdquo Journal of the Physical Society of Japan vol13 no 12 pp 1444ndash1451 1958

[10] W Koster and E Wachtel ldquoConstitution and magnetic proper-ties of aluminum-manganese alloyswithmore than 5AtMnrdquoZeitschrift fuer Metallkunde vol 51 pp 271ndash280 1960

[11] Y Minamino T Yamane H Araki et al ldquoSolid solubilities ofmanganese and titanium in aluminum at 01 MPa and 21 GPardquoMetallurgical Transactions A vol 22 no 3 pp 783ndash786 1991

[12] H Okamoto ldquoAl-Mn (Aluminum-Manganese)rdquo Journal ofPhase Equilibria vol 18 no 4 pp 398ndash399 1997

[13] M A Taylor ldquoIntermetallig phases in the aluminiumman-ganese binary systemrdquo Acta Metallurgica vol 8 no 4 pp 256ndash262 1960

[14] S Wasiur-Rahman andMMedraj ldquoA thermodynamic descrip-tion of the Al-Ca-Zn ternary systemrdquoCalphad vol 33 no 3 pp584ndash598 2009

[15] H Okamoto and L E Tanner ldquoThe Mn-Zn (Manganese-Zinc)systemrdquo Bulletin of Alloy Phase Diagrams vol 11 no 4 pp 377ndash384 1990

[16] S Tezuka S Sakai and Y Nakagawa ldquoFerromagnetism of Mn-Zn alloyrdquo Journal of the Physical Society of Japan vol 15 no 5p 931 1960

[17] Y Nakagawa and T Hori ldquoMagnetic transition and crystaldistortion in MnHg andMnZn

3

rdquo Journal of the Physical Societyof Japan vol 17 no 8 pp 1313ndash1314 1962

[18] B Henderson and R J M Willcox ldquoLattice spacing relation-ships in hexagonal close-packed Silver-Zinc-Manganese alloysrdquoPhilosophical Magazine vol 9 no 101 pp 829ndash846 1964

[19] R A Farrar and H W King ldquoAxial ratios and solubility limitsof HCP 120578 and 120576 phases in the systems CdMn and ZnMnrdquoMetallography vol 3 no 1 pp 61ndash70 1970

[20] J L Liang Y Du C Z Liao et al ldquoExperimental investigationon the phase equilibria of the Mn-Ni-Zn system at 400∘CrdquoJournal of Alloys and Compounds vol 489 no 2 pp 362ndash3682010

[21] J L Liang Y Du Q Z Zhao et al ldquoDetermination of the phaseequilibria in the Mn-Sn-Zn system at 500∘ Crdquo MetallurgicalandMaterials Transactions A PhysicalMetallurgy andMaterialsScience vol 40 no 12 pp 2909ndash2918 2009

[22] H Xu X Xiong L Zhang YDu and PWang ldquoPhase equilibriaof the Mn-Si-Zn system at 600∘Crdquo Metallurgical and MaterialsTransactions A Physical Metallurgy and Materials Science vol40 no 9 pp 2042ndash2047 2009

[23] E Gebhardt ldquoDie zinkecke des dreistoffsystems zink-aluminium-manganrdquo Zeitschrift fur Metallkunde vol 34pp 259ndash263 1942

[24] G V Raynor and D W Wakeman ldquoThe intermetallic com-pound phases of the system Aluminium-Manganese-Zincrdquo

Proceedings of the Royal Society of London A Mathematical andPhysical Sciences vol 190 no 1020 pp 82ndash101 1947

[25] K Robinson ldquoThe determination of the crystal structure ofNi4

Mn11

Al60

rdquo Acta Crystallographica vol 7 part 6-7 pp 494ndash497 1954

[26] A Damjanovic ldquoThe structure analysis of the T3

(A1MnZn)compoundrdquo Acta Crystallographica vol 14 pp 982ndash987 1961

[27] R J Schaefer L A Bendersky D Shechtman W J Boettingerand F S Biancaniello ldquoIcosahedral and decagonal phase forma-tion in Al-Mn Alloysrdquo Metallurgical transactions A vol 17 no12 pp 2117ndash2125 1986

[28] A Singh S Ranganathan and L A Bendersky ldquoQuasicrys-talline phases and their approximants inAl-Mn-Zn alloysrdquoActaMaterialia vol 45 no 12 pp 5327ndash5336 1997

[29] J S Kirkaldy and L C Brown ldquoDiffusion behavior in theternarymultiphase systemsrdquoCanadianMetallurgicalQuarterlyvol 2 no 1 pp 90ndash115 1963

[30] J B Clark ldquoConventions for plotting the diffusion paths inmultiphase ternary diffusion couples on the isothermal sectionof a ternary phase diagramrdquo Transactions of the MetallurgicalSociety of AIME vol 227 pp 1250ndash1251 1963

[31] A A Kodentsov G F Bastin and F J J van Loo ldquoThe diffusioncouple technique in phase diagram determinationrdquo Journal ofAlloys and Compounds vol 320 no 2 pp 207ndash217 2001

[32] M A Khan Thermodynamic modeling of the MgndashMnndash(Al Zn)systems [MS thesis] Concordia University 2009

[33] PANalytical Ver22b (222) PANalytical Almelo The Nether-lands 2006

[34] H Putz and K Brandenburg Pearsonrsquos Crystal Data CrystalStructure Database for Inorganic Compounds CD-ROM Soft-ware Version 13

[35] P Ghosh and M Medraj ldquoThermodynamic calculation of theMg-Mn-Zn and Mg-Mn-Ce systems and re-optimization oftheir constitutive binariesrdquo Calphad Computer Coupling ofPhase Diagrams andThermochemistry vol 41 pp 89ndash107 2013

[36] A Prince Alloy Phase Equilibria Elsevier Amsterdam TheNetherland 1966

[37] L Y H John ldquoSchreinemakers rule as applied to non-degenerate ternary systemsrdquoThe Journal of Young Investigatorsvol 19 no 11 2009

Submit your manuscripts athttpwwwhindawicom

ScientificaHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CorrosionInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Polymer ScienceInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CeramicsJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CompositesJournal of

NanoparticlesJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

International Journal of

Biomaterials

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

NanoscienceJournal of

TextilesHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Journal of

NanotechnologyHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

CrystallographyJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CoatingsJournal of

Advances in

Materials Science and EngineeringHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Smart Materials Research

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

MetallurgyJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

BioMed Research International

MaterialsJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Nano

materials

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal ofNanomaterials

Journal of Materials 11

Al8Mn5

Al11Mn4

80120583m

(a)

Al8Mn5

50120583m

(b)

20 25 30 35 40 45 50 550

100

200

300

400

500

600

Cou

nts

Position of 2120579

Al8Mn5

98 Al8Mn5

(c)

Figure 12 (a) Backscattered electron image of sample 14 (b) backscattered electron image of sample 15 (c) XRD spectrum of sample 15

Thus DC 4 (Mn-Al65Mn30Zn5) was prepared in order to

determine the homogeneity range of Al8Mn5in this ternary

system Because Al11Mn4has higher growth rate one end

member of DC 4 (Mn-Al65Mn30Zn5) has been selected near

the Al8Mn5region to increase the atomic exchange between

Al and Mn From the backscattered electron image of DC4 (Mn-Al

65Mn30Zn5) shown in Figure 11(a) Al

8Mn5formed

a thick layer and the color changed along with decreasingMn content which suggests the presence of a homogeneityrange Line-scan shown in Figure 11(b) was carried outto determine the homogeneity range of Al

8Mn5 In the

Al11Mn4+ Al8Mn5two-phase region dotted lines denote

the concentrations of elements in Al11Mn4and solid lines

represent the concentrations of elements in Al8Mn5 The

SEMEDS analysis showed that Al8Mn5has ternary solubility

of 9 at Zn and Al11Mn4has maximum ternary solubility

of 4 at Zn Al concentration in Al8Mn5layer varied from

49 at to 58 atAl11Mn4and Al

8Mn5showed extended ternary solubility

in this system at 400∘C In order to confirm the resultsobtained from previous diffusion couples four key alloys(14 to 17) were prepared The composition and phase iden-tification of these key samples are summarized in Table 2The phase relations obtained from EPMA showed greatconsistency with the XRD results Backscattered electronimage of sample 14 is shown in Figure 12(a) From EPMA

point analysis Al11Mn4has a ternary solubility of about 4 at

Zn and Al8Mn5has a maximum ternary solubility of 10 at

Zn These results were consistent with the previous EPMAobservation of samples 9 and 11 Figure 12(b) shows thatsample 15 contains mainly Al

8Mn5whose ternary solubility

was measured around 4 at Zn The XRD analysis also con-firmed that Al

8Mn5is dominating in sample 15 as shown in

Figure 12(c)There are a few unlabeled small peaks indicatingthe presence of Al

11Mn4traces which could not be identified

in the current study because of their low intensity

332 Single Region of 120576 Phase Controversy on whether120576 has three-phase separations reported in the assessmentof Okamoto and Tanner [15] is still not resolved In thecurrent study one end-member of DC 5 (Al-Mn

32Zn68)

has a composition in the 120576-phase region EPMA line-scanindicated that 120576-phase has continuous binary solubility rangesreaching fromMn

32Zn68to Mn

40Zn60at 400∘CThis finding

also corresponds to the Mn-Zn binary system which wasreported by [32 35] The backscattered electron image of DC5 (Al-Mn

32Zn68) is presented in Figure 13 Five phases have

been identified 120576 Al-rich 120573-Mn1015840 Al8Mn5 Al11Mn4 and Al-

fcc In the current experimental investigation the maximumsolubility of Zn in 120573-Mn1015840 was measured as 4 at Single 120576-phase region with the Mn content from 32 to 40 at was

12 Journal of Materials

Al8Mn5

120573-Mn998400

Al11Mn4

Al-fcc

Mn32Zn68(120576)

Figure 13 Backscattered electron image of DC 5 (Al-Mn32

Zn68

)

observed at 400∘C and nothing indicated the presence ofphase separation in this composition range From the resultsof sample 17 (Al

30Mn35Zn35) 120576-phase was found to have

limited ternary solubility of 4 at Al

34 Isothermal Section of Al-Mn-Zn System at 400∘C Com-bining the results which were obtained from the diffusioncouples with those obtained from the key alloys the Al-Mn-Zn isothermal section at 400∘C was constructed and pre-sented in Figure 14 Solid lines represent the experimentallyverified phase boundaries and ternary solubility of binaryphases Dotted lines are the estimated phase relationshipswhich were not confirmed in the current study They wereconstructed based on the Gibbs phase rule [36] and Schreine-makerrsquos rule [37] Grey blue and green areas indicate thesingle two-phase and three-phase regions separately asshown in Figure 14

4 Conclusion

The Al-Mn-Zn isothermal section at 400∘C was constructedbased on the current experimental results of diffusion coupletechnique and selected key alloys Phase relationships andsolubility limits have been determined for the ternary andbinary compounds The previously reported ternary com-pound T3 was confirmed in the current study and is denotedas 1205912in this paper Two new ternary compounds 120591

1and 1205913

have been found in this system at 400∘C 1205911does not show

significant solubility ranges and is considered stoichiometric1205913is a solid solution with a narrow homogeneity range

The formulae of the three Al-Mn-Zn ternary intermetalliccompounds are 120591

1 Al31Mn8Zn11 1205912 Al72Mn16Zn12 and 120591

3

Al119909Mn119910Zn119911(119909 = 9ndash13 at 119910 = 11ndash15 at 119911 = 75ndash77 at) A

single-phase region of Al8Mn5with extended solubility was

found in this system at 400∘C Based on the current findingsthe ternary solubilities of the Al

8Mn5 Al4Mn and Al

11Mn4

compounds have been determined as 10 at 6 at and 4 atZn respectively 120576 and Mn

5Zn21

exhibit their maximumsolubilities of 4 at and 5 at Al The solubility of Zn in120573-Mn1015840 has been found to be 4 at and 120573-Mn10158401015840 has ternarysolubility of 3 at Al

Mole

frac

tion

Al

0 20 40 60 80 100

0

20

40

60

80

100 0

20

40

60

80

100

Single-phase regionTwo-phase region

Mole fraction M

n

Zn

Mn

AlMole fraction Zn

400∘C

Al8Mn5

Al 8Mn 5

Al6MnAl4Mn

120573-Mn998400 120573-M

n998400

120573-Mn998400998400

Al11Mn4

Al12Mn MnZn13MnZn9

Mn5Zn21

120576

Three-phase region

1205912 1205911

Al-f

cc

Liqu

idZn

-HCP

120573-Mn998400 + 120573-Mn998400998400

120573-Mn 998400+ 120573-Mn 998400998400

+ 120576

Al8Mn5 + 120573- Mn998400

Al8Mn5 + 120576Al8Mn

5 + Mn5Zn

21 + 1205913

Al8Mn5 + Al11Mn4 + 12059131205911 + Al11Mn4 + 1205913

1205911 + Al-fcc + 1205913

Al8Mn5 + 120573-Mn 998400

+ 120576

Figure 14 Isothermal section of Al-Mn-Zn ternary system at 400∘Cconstructed by diffusion couples and key samples

Conflict of Interests

The authors declare that there is no conflict of interestsof any sort that might have influenced the discussions orconclusions of this paper

Acknowledgments

Financial support from General Motors of Canada Ltd andthe Natural Sciences and Engineering Research Councilof Canada (NSERC) through the CRD grant program isgratefully acknowledged The authors would also like toacknowledge the help of Mohammad Mezbahul-Islam ofMechanical Engineering Department Concordia Universityfor his valuable suggestions

References

[1] G S Cole and A M Sherman ldquoLight weight materials forautomotive applicationsrdquo Materials Characterization vol 35no 1 pp 3ndash9 1995

[2] S W Nam and B O Kong ldquoDevelopment of weldable highstrength alalloyrdquo KOSEF Technical Report 1993

[3] H S Cho and S W Nam ldquoA study of the low cycle fatigueproperties of weldable Al-Zn-Mg-Mn Alloy and Al 7039 invarious environmentsrdquo Journal of Korean Institute of Metals andMaterials vol 32 no 7 pp 765ndash770 1994

[4] M Ohno D Mirkovic and R Schmid-Fetzer ldquoLiquidus andsolidus temperatures of Mg-rich Mg-Al-Mn-Zn alloysrdquo ActaMaterialia vol 54 no 15 pp 3883ndash3891 2006

[5] N Gao Y H Liu and N-Y Tang ldquoAn experimental study ofthe liquid domain of the Zn-Fe-Al-Mn quaternary system at

Journal of Materials 13

460∘Crdquo Journal of Phase Equilibria and Diffusion vol 31 no 6pp 523ndash531 2010

[6] M A Khan and M Medraj ldquoThermodynamic descriptionof the Mg-Mn Al-Mn and Mg-Al-Mn systems using themodified quasichemical model for the liquid phasesrdquoMaterialsTransactions vol 50 no 5 pp 1113ndash1122 2009

[7] C Muller H Stadelmaier B Reinsch and G Petzow ldquoMet-allurgy of the magnetic 120591-phase in Mn-Al and Mn-Al-CrdquoZeitschrift fuer Metallkunde vol 87 no 7 pp 594ndash597 1996

[8] A Shukla and A D Pelton ldquoThermodynamic assessment of theAl-Mn andMg-Al-Mn systemsrdquo Journal of Phase Equilibria andDiffusion vol 30 no 1 pp 28ndash39 2009

[9] H Kono ldquoOn the ferromagnetic phase in manganese-aluminum systemrdquo Journal of the Physical Society of Japan vol13 no 12 pp 1444ndash1451 1958

[10] W Koster and E Wachtel ldquoConstitution and magnetic proper-ties of aluminum-manganese alloyswithmore than 5AtMnrdquoZeitschrift fuer Metallkunde vol 51 pp 271ndash280 1960

[11] Y Minamino T Yamane H Araki et al ldquoSolid solubilities ofmanganese and titanium in aluminum at 01 MPa and 21 GPardquoMetallurgical Transactions A vol 22 no 3 pp 783ndash786 1991

[12] H Okamoto ldquoAl-Mn (Aluminum-Manganese)rdquo Journal ofPhase Equilibria vol 18 no 4 pp 398ndash399 1997

[13] M A Taylor ldquoIntermetallig phases in the aluminiumman-ganese binary systemrdquo Acta Metallurgica vol 8 no 4 pp 256ndash262 1960

[14] S Wasiur-Rahman andMMedraj ldquoA thermodynamic descrip-tion of the Al-Ca-Zn ternary systemrdquoCalphad vol 33 no 3 pp584ndash598 2009

[15] H Okamoto and L E Tanner ldquoThe Mn-Zn (Manganese-Zinc)systemrdquo Bulletin of Alloy Phase Diagrams vol 11 no 4 pp 377ndash384 1990

[16] S Tezuka S Sakai and Y Nakagawa ldquoFerromagnetism of Mn-Zn alloyrdquo Journal of the Physical Society of Japan vol 15 no 5p 931 1960

[17] Y Nakagawa and T Hori ldquoMagnetic transition and crystaldistortion in MnHg andMnZn

3

rdquo Journal of the Physical Societyof Japan vol 17 no 8 pp 1313ndash1314 1962

[18] B Henderson and R J M Willcox ldquoLattice spacing relation-ships in hexagonal close-packed Silver-Zinc-Manganese alloysrdquoPhilosophical Magazine vol 9 no 101 pp 829ndash846 1964

[19] R A Farrar and H W King ldquoAxial ratios and solubility limitsof HCP 120578 and 120576 phases in the systems CdMn and ZnMnrdquoMetallography vol 3 no 1 pp 61ndash70 1970

[20] J L Liang Y Du C Z Liao et al ldquoExperimental investigationon the phase equilibria of the Mn-Ni-Zn system at 400∘CrdquoJournal of Alloys and Compounds vol 489 no 2 pp 362ndash3682010

[21] J L Liang Y Du Q Z Zhao et al ldquoDetermination of the phaseequilibria in the Mn-Sn-Zn system at 500∘ Crdquo MetallurgicalandMaterials Transactions A PhysicalMetallurgy andMaterialsScience vol 40 no 12 pp 2909ndash2918 2009

[22] H Xu X Xiong L Zhang YDu and PWang ldquoPhase equilibriaof the Mn-Si-Zn system at 600∘Crdquo Metallurgical and MaterialsTransactions A Physical Metallurgy and Materials Science vol40 no 9 pp 2042ndash2047 2009

[23] E Gebhardt ldquoDie zinkecke des dreistoffsystems zink-aluminium-manganrdquo Zeitschrift fur Metallkunde vol 34pp 259ndash263 1942

[24] G V Raynor and D W Wakeman ldquoThe intermetallic com-pound phases of the system Aluminium-Manganese-Zincrdquo

Proceedings of the Royal Society of London A Mathematical andPhysical Sciences vol 190 no 1020 pp 82ndash101 1947

[25] K Robinson ldquoThe determination of the crystal structure ofNi4

Mn11

Al60

rdquo Acta Crystallographica vol 7 part 6-7 pp 494ndash497 1954

[26] A Damjanovic ldquoThe structure analysis of the T3

(A1MnZn)compoundrdquo Acta Crystallographica vol 14 pp 982ndash987 1961

[27] R J Schaefer L A Bendersky D Shechtman W J Boettingerand F S Biancaniello ldquoIcosahedral and decagonal phase forma-tion in Al-Mn Alloysrdquo Metallurgical transactions A vol 17 no12 pp 2117ndash2125 1986

[28] A Singh S Ranganathan and L A Bendersky ldquoQuasicrys-talline phases and their approximants inAl-Mn-Zn alloysrdquoActaMaterialia vol 45 no 12 pp 5327ndash5336 1997

[29] J S Kirkaldy and L C Brown ldquoDiffusion behavior in theternarymultiphase systemsrdquoCanadianMetallurgicalQuarterlyvol 2 no 1 pp 90ndash115 1963

[30] J B Clark ldquoConventions for plotting the diffusion paths inmultiphase ternary diffusion couples on the isothermal sectionof a ternary phase diagramrdquo Transactions of the MetallurgicalSociety of AIME vol 227 pp 1250ndash1251 1963

[31] A A Kodentsov G F Bastin and F J J van Loo ldquoThe diffusioncouple technique in phase diagram determinationrdquo Journal ofAlloys and Compounds vol 320 no 2 pp 207ndash217 2001

[32] M A Khan Thermodynamic modeling of the MgndashMnndash(Al Zn)systems [MS thesis] Concordia University 2009

[33] PANalytical Ver22b (222) PANalytical Almelo The Nether-lands 2006

[34] H Putz and K Brandenburg Pearsonrsquos Crystal Data CrystalStructure Database for Inorganic Compounds CD-ROM Soft-ware Version 13

[35] P Ghosh and M Medraj ldquoThermodynamic calculation of theMg-Mn-Zn and Mg-Mn-Ce systems and re-optimization oftheir constitutive binariesrdquo Calphad Computer Coupling ofPhase Diagrams andThermochemistry vol 41 pp 89ndash107 2013

[36] A Prince Alloy Phase Equilibria Elsevier Amsterdam TheNetherland 1966

[37] L Y H John ldquoSchreinemakers rule as applied to non-degenerate ternary systemsrdquoThe Journal of Young Investigatorsvol 19 no 11 2009

Submit your manuscripts athttpwwwhindawicom

ScientificaHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CorrosionInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Polymer ScienceInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CeramicsJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CompositesJournal of

NanoparticlesJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

International Journal of

Biomaterials

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

NanoscienceJournal of

TextilesHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Journal of

NanotechnologyHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

CrystallographyJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CoatingsJournal of

Advances in

Materials Science and EngineeringHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Smart Materials Research

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

MetallurgyJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

BioMed Research International

MaterialsJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Nano

materials

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal ofNanomaterials

12 Journal of Materials

Al8Mn5

120573-Mn998400

Al11Mn4

Al-fcc

Mn32Zn68(120576)

Figure 13 Backscattered electron image of DC 5 (Al-Mn32

Zn68

)

observed at 400∘C and nothing indicated the presence ofphase separation in this composition range From the resultsof sample 17 (Al

30Mn35Zn35) 120576-phase was found to have

limited ternary solubility of 4 at Al

34 Isothermal Section of Al-Mn-Zn System at 400∘C Com-bining the results which were obtained from the diffusioncouples with those obtained from the key alloys the Al-Mn-Zn isothermal section at 400∘C was constructed and pre-sented in Figure 14 Solid lines represent the experimentallyverified phase boundaries and ternary solubility of binaryphases Dotted lines are the estimated phase relationshipswhich were not confirmed in the current study They wereconstructed based on the Gibbs phase rule [36] and Schreine-makerrsquos rule [37] Grey blue and green areas indicate thesingle two-phase and three-phase regions separately asshown in Figure 14

4 Conclusion

The Al-Mn-Zn isothermal section at 400∘C was constructedbased on the current experimental results of diffusion coupletechnique and selected key alloys Phase relationships andsolubility limits have been determined for the ternary andbinary compounds The previously reported ternary com-pound T3 was confirmed in the current study and is denotedas 1205912in this paper Two new ternary compounds 120591

1and 1205913

have been found in this system at 400∘C 1205911does not show

significant solubility ranges and is considered stoichiometric1205913is a solid solution with a narrow homogeneity range

The formulae of the three Al-Mn-Zn ternary intermetalliccompounds are 120591

1 Al31Mn8Zn11 1205912 Al72Mn16Zn12 and 120591

3

Al119909Mn119910Zn119911(119909 = 9ndash13 at 119910 = 11ndash15 at 119911 = 75ndash77 at) A

single-phase region of Al8Mn5with extended solubility was

found in this system at 400∘C Based on the current findingsthe ternary solubilities of the Al

8Mn5 Al4Mn and Al

11Mn4

compounds have been determined as 10 at 6 at and 4 atZn respectively 120576 and Mn

5Zn21

exhibit their maximumsolubilities of 4 at and 5 at Al The solubility of Zn in120573-Mn1015840 has been found to be 4 at and 120573-Mn10158401015840 has ternarysolubility of 3 at Al

Mole

frac

tion

Al

0 20 40 60 80 100

0

20

40

60

80

100 0

20

40

60

80

100

Single-phase regionTwo-phase region

Mole fraction M

n

Zn

Mn

AlMole fraction Zn

400∘C

Al8Mn5

Al 8Mn 5

Al6MnAl4Mn

120573-Mn998400 120573-M

n998400

120573-Mn998400998400

Al11Mn4

Al12Mn MnZn13MnZn9

Mn5Zn21

120576

Three-phase region

1205912 1205911

Al-f

cc

Liqu

idZn

-HCP

120573-Mn998400 + 120573-Mn998400998400

120573-Mn 998400+ 120573-Mn 998400998400

+ 120576

Al8Mn5 + 120573- Mn998400

Al8Mn5 + 120576Al8Mn

5 + Mn5Zn

21 + 1205913

Al8Mn5 + Al11Mn4 + 12059131205911 + Al11Mn4 + 1205913

1205911 + Al-fcc + 1205913

Al8Mn5 + 120573-Mn 998400

+ 120576

Figure 14 Isothermal section of Al-Mn-Zn ternary system at 400∘Cconstructed by diffusion couples and key samples

Conflict of Interests

The authors declare that there is no conflict of interestsof any sort that might have influenced the discussions orconclusions of this paper

Acknowledgments

Financial support from General Motors of Canada Ltd andthe Natural Sciences and Engineering Research Councilof Canada (NSERC) through the CRD grant program isgratefully acknowledged The authors would also like toacknowledge the help of Mohammad Mezbahul-Islam ofMechanical Engineering Department Concordia Universityfor his valuable suggestions

References

[1] G S Cole and A M Sherman ldquoLight weight materials forautomotive applicationsrdquo Materials Characterization vol 35no 1 pp 3ndash9 1995

[2] S W Nam and B O Kong ldquoDevelopment of weldable highstrength alalloyrdquo KOSEF Technical Report 1993

[3] H S Cho and S W Nam ldquoA study of the low cycle fatigueproperties of weldable Al-Zn-Mg-Mn Alloy and Al 7039 invarious environmentsrdquo Journal of Korean Institute of Metals andMaterials vol 32 no 7 pp 765ndash770 1994

[4] M Ohno D Mirkovic and R Schmid-Fetzer ldquoLiquidus andsolidus temperatures of Mg-rich Mg-Al-Mn-Zn alloysrdquo ActaMaterialia vol 54 no 15 pp 3883ndash3891 2006

[5] N Gao Y H Liu and N-Y Tang ldquoAn experimental study ofthe liquid domain of the Zn-Fe-Al-Mn quaternary system at

Journal of Materials 13

460∘Crdquo Journal of Phase Equilibria and Diffusion vol 31 no 6pp 523ndash531 2010

[6] M A Khan and M Medraj ldquoThermodynamic descriptionof the Mg-Mn Al-Mn and Mg-Al-Mn systems using themodified quasichemical model for the liquid phasesrdquoMaterialsTransactions vol 50 no 5 pp 1113ndash1122 2009

[7] C Muller H Stadelmaier B Reinsch and G Petzow ldquoMet-allurgy of the magnetic 120591-phase in Mn-Al and Mn-Al-CrdquoZeitschrift fuer Metallkunde vol 87 no 7 pp 594ndash597 1996

[8] A Shukla and A D Pelton ldquoThermodynamic assessment of theAl-Mn andMg-Al-Mn systemsrdquo Journal of Phase Equilibria andDiffusion vol 30 no 1 pp 28ndash39 2009

[9] H Kono ldquoOn the ferromagnetic phase in manganese-aluminum systemrdquo Journal of the Physical Society of Japan vol13 no 12 pp 1444ndash1451 1958

[10] W Koster and E Wachtel ldquoConstitution and magnetic proper-ties of aluminum-manganese alloyswithmore than 5AtMnrdquoZeitschrift fuer Metallkunde vol 51 pp 271ndash280 1960

[11] Y Minamino T Yamane H Araki et al ldquoSolid solubilities ofmanganese and titanium in aluminum at 01 MPa and 21 GPardquoMetallurgical Transactions A vol 22 no 3 pp 783ndash786 1991

[12] H Okamoto ldquoAl-Mn (Aluminum-Manganese)rdquo Journal ofPhase Equilibria vol 18 no 4 pp 398ndash399 1997

[13] M A Taylor ldquoIntermetallig phases in the aluminiumman-ganese binary systemrdquo Acta Metallurgica vol 8 no 4 pp 256ndash262 1960

[14] S Wasiur-Rahman andMMedraj ldquoA thermodynamic descrip-tion of the Al-Ca-Zn ternary systemrdquoCalphad vol 33 no 3 pp584ndash598 2009

[15] H Okamoto and L E Tanner ldquoThe Mn-Zn (Manganese-Zinc)systemrdquo Bulletin of Alloy Phase Diagrams vol 11 no 4 pp 377ndash384 1990

[16] S Tezuka S Sakai and Y Nakagawa ldquoFerromagnetism of Mn-Zn alloyrdquo Journal of the Physical Society of Japan vol 15 no 5p 931 1960

[17] Y Nakagawa and T Hori ldquoMagnetic transition and crystaldistortion in MnHg andMnZn

3

rdquo Journal of the Physical Societyof Japan vol 17 no 8 pp 1313ndash1314 1962

[18] B Henderson and R J M Willcox ldquoLattice spacing relation-ships in hexagonal close-packed Silver-Zinc-Manganese alloysrdquoPhilosophical Magazine vol 9 no 101 pp 829ndash846 1964

[19] R A Farrar and H W King ldquoAxial ratios and solubility limitsof HCP 120578 and 120576 phases in the systems CdMn and ZnMnrdquoMetallography vol 3 no 1 pp 61ndash70 1970

[20] J L Liang Y Du C Z Liao et al ldquoExperimental investigationon the phase equilibria of the Mn-Ni-Zn system at 400∘CrdquoJournal of Alloys and Compounds vol 489 no 2 pp 362ndash3682010

[21] J L Liang Y Du Q Z Zhao et al ldquoDetermination of the phaseequilibria in the Mn-Sn-Zn system at 500∘ Crdquo MetallurgicalandMaterials Transactions A PhysicalMetallurgy andMaterialsScience vol 40 no 12 pp 2909ndash2918 2009

[22] H Xu X Xiong L Zhang YDu and PWang ldquoPhase equilibriaof the Mn-Si-Zn system at 600∘Crdquo Metallurgical and MaterialsTransactions A Physical Metallurgy and Materials Science vol40 no 9 pp 2042ndash2047 2009

[23] E Gebhardt ldquoDie zinkecke des dreistoffsystems zink-aluminium-manganrdquo Zeitschrift fur Metallkunde vol 34pp 259ndash263 1942

[24] G V Raynor and D W Wakeman ldquoThe intermetallic com-pound phases of the system Aluminium-Manganese-Zincrdquo

Proceedings of the Royal Society of London A Mathematical andPhysical Sciences vol 190 no 1020 pp 82ndash101 1947

[25] K Robinson ldquoThe determination of the crystal structure ofNi4

Mn11

Al60

rdquo Acta Crystallographica vol 7 part 6-7 pp 494ndash497 1954

[26] A Damjanovic ldquoThe structure analysis of the T3

(A1MnZn)compoundrdquo Acta Crystallographica vol 14 pp 982ndash987 1961

[27] R J Schaefer L A Bendersky D Shechtman W J Boettingerand F S Biancaniello ldquoIcosahedral and decagonal phase forma-tion in Al-Mn Alloysrdquo Metallurgical transactions A vol 17 no12 pp 2117ndash2125 1986

[28] A Singh S Ranganathan and L A Bendersky ldquoQuasicrys-talline phases and their approximants inAl-Mn-Zn alloysrdquoActaMaterialia vol 45 no 12 pp 5327ndash5336 1997

[29] J S Kirkaldy and L C Brown ldquoDiffusion behavior in theternarymultiphase systemsrdquoCanadianMetallurgicalQuarterlyvol 2 no 1 pp 90ndash115 1963

[30] J B Clark ldquoConventions for plotting the diffusion paths inmultiphase ternary diffusion couples on the isothermal sectionof a ternary phase diagramrdquo Transactions of the MetallurgicalSociety of AIME vol 227 pp 1250ndash1251 1963

[31] A A Kodentsov G F Bastin and F J J van Loo ldquoThe diffusioncouple technique in phase diagram determinationrdquo Journal ofAlloys and Compounds vol 320 no 2 pp 207ndash217 2001

[32] M A Khan Thermodynamic modeling of the MgndashMnndash(Al Zn)systems [MS thesis] Concordia University 2009

[33] PANalytical Ver22b (222) PANalytical Almelo The Nether-lands 2006

[34] H Putz and K Brandenburg Pearsonrsquos Crystal Data CrystalStructure Database for Inorganic Compounds CD-ROM Soft-ware Version 13

[35] P Ghosh and M Medraj ldquoThermodynamic calculation of theMg-Mn-Zn and Mg-Mn-Ce systems and re-optimization oftheir constitutive binariesrdquo Calphad Computer Coupling ofPhase Diagrams andThermochemistry vol 41 pp 89ndash107 2013

[36] A Prince Alloy Phase Equilibria Elsevier Amsterdam TheNetherland 1966

[37] L Y H John ldquoSchreinemakers rule as applied to non-degenerate ternary systemsrdquoThe Journal of Young Investigatorsvol 19 no 11 2009

Submit your manuscripts athttpwwwhindawicom

ScientificaHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CorrosionInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Polymer ScienceInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CeramicsJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CompositesJournal of

NanoparticlesJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

International Journal of

Biomaterials

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

NanoscienceJournal of

TextilesHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Journal of

NanotechnologyHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

CrystallographyJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CoatingsJournal of

Advances in

Materials Science and EngineeringHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Smart Materials Research

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

MetallurgyJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

BioMed Research International

MaterialsJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Nano

materials

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal ofNanomaterials

Journal of Materials 13

460∘Crdquo Journal of Phase Equilibria and Diffusion vol 31 no 6pp 523ndash531 2010

[6] M A Khan and M Medraj ldquoThermodynamic descriptionof the Mg-Mn Al-Mn and Mg-Al-Mn systems using themodified quasichemical model for the liquid phasesrdquoMaterialsTransactions vol 50 no 5 pp 1113ndash1122 2009

[7] C Muller H Stadelmaier B Reinsch and G Petzow ldquoMet-allurgy of the magnetic 120591-phase in Mn-Al and Mn-Al-CrdquoZeitschrift fuer Metallkunde vol 87 no 7 pp 594ndash597 1996

[8] A Shukla and A D Pelton ldquoThermodynamic assessment of theAl-Mn andMg-Al-Mn systemsrdquo Journal of Phase Equilibria andDiffusion vol 30 no 1 pp 28ndash39 2009

[9] H Kono ldquoOn the ferromagnetic phase in manganese-aluminum systemrdquo Journal of the Physical Society of Japan vol13 no 12 pp 1444ndash1451 1958

[10] W Koster and E Wachtel ldquoConstitution and magnetic proper-ties of aluminum-manganese alloyswithmore than 5AtMnrdquoZeitschrift fuer Metallkunde vol 51 pp 271ndash280 1960

[11] Y Minamino T Yamane H Araki et al ldquoSolid solubilities ofmanganese and titanium in aluminum at 01 MPa and 21 GPardquoMetallurgical Transactions A vol 22 no 3 pp 783ndash786 1991

[12] H Okamoto ldquoAl-Mn (Aluminum-Manganese)rdquo Journal ofPhase Equilibria vol 18 no 4 pp 398ndash399 1997

[13] M A Taylor ldquoIntermetallig phases in the aluminiumman-ganese binary systemrdquo Acta Metallurgica vol 8 no 4 pp 256ndash262 1960

[14] S Wasiur-Rahman andMMedraj ldquoA thermodynamic descrip-tion of the Al-Ca-Zn ternary systemrdquoCalphad vol 33 no 3 pp584ndash598 2009

[15] H Okamoto and L E Tanner ldquoThe Mn-Zn (Manganese-Zinc)systemrdquo Bulletin of Alloy Phase Diagrams vol 11 no 4 pp 377ndash384 1990

[16] S Tezuka S Sakai and Y Nakagawa ldquoFerromagnetism of Mn-Zn alloyrdquo Journal of the Physical Society of Japan vol 15 no 5p 931 1960

[17] Y Nakagawa and T Hori ldquoMagnetic transition and crystaldistortion in MnHg andMnZn

3

rdquo Journal of the Physical Societyof Japan vol 17 no 8 pp 1313ndash1314 1962

[18] B Henderson and R J M Willcox ldquoLattice spacing relation-ships in hexagonal close-packed Silver-Zinc-Manganese alloysrdquoPhilosophical Magazine vol 9 no 101 pp 829ndash846 1964

[19] R A Farrar and H W King ldquoAxial ratios and solubility limitsof HCP 120578 and 120576 phases in the systems CdMn and ZnMnrdquoMetallography vol 3 no 1 pp 61ndash70 1970

[20] J L Liang Y Du C Z Liao et al ldquoExperimental investigationon the phase equilibria of the Mn-Ni-Zn system at 400∘CrdquoJournal of Alloys and Compounds vol 489 no 2 pp 362ndash3682010

[21] J L Liang Y Du Q Z Zhao et al ldquoDetermination of the phaseequilibria in the Mn-Sn-Zn system at 500∘ Crdquo MetallurgicalandMaterials Transactions A PhysicalMetallurgy andMaterialsScience vol 40 no 12 pp 2909ndash2918 2009

[22] H Xu X Xiong L Zhang YDu and PWang ldquoPhase equilibriaof the Mn-Si-Zn system at 600∘Crdquo Metallurgical and MaterialsTransactions A Physical Metallurgy and Materials Science vol40 no 9 pp 2042ndash2047 2009

[23] E Gebhardt ldquoDie zinkecke des dreistoffsystems zink-aluminium-manganrdquo Zeitschrift fur Metallkunde vol 34pp 259ndash263 1942

[24] G V Raynor and D W Wakeman ldquoThe intermetallic com-pound phases of the system Aluminium-Manganese-Zincrdquo

Proceedings of the Royal Society of London A Mathematical andPhysical Sciences vol 190 no 1020 pp 82ndash101 1947

[25] K Robinson ldquoThe determination of the crystal structure ofNi4

Mn11

Al60

rdquo Acta Crystallographica vol 7 part 6-7 pp 494ndash497 1954

[26] A Damjanovic ldquoThe structure analysis of the T3

(A1MnZn)compoundrdquo Acta Crystallographica vol 14 pp 982ndash987 1961

[27] R J Schaefer L A Bendersky D Shechtman W J Boettingerand F S Biancaniello ldquoIcosahedral and decagonal phase forma-tion in Al-Mn Alloysrdquo Metallurgical transactions A vol 17 no12 pp 2117ndash2125 1986

[28] A Singh S Ranganathan and L A Bendersky ldquoQuasicrys-talline phases and their approximants inAl-Mn-Zn alloysrdquoActaMaterialia vol 45 no 12 pp 5327ndash5336 1997

[29] J S Kirkaldy and L C Brown ldquoDiffusion behavior in theternarymultiphase systemsrdquoCanadianMetallurgicalQuarterlyvol 2 no 1 pp 90ndash115 1963

[30] J B Clark ldquoConventions for plotting the diffusion paths inmultiphase ternary diffusion couples on the isothermal sectionof a ternary phase diagramrdquo Transactions of the MetallurgicalSociety of AIME vol 227 pp 1250ndash1251 1963

[31] A A Kodentsov G F Bastin and F J J van Loo ldquoThe diffusioncouple technique in phase diagram determinationrdquo Journal ofAlloys and Compounds vol 320 no 2 pp 207ndash217 2001

[32] M A Khan Thermodynamic modeling of the MgndashMnndash(Al Zn)systems [MS thesis] Concordia University 2009

[33] PANalytical Ver22b (222) PANalytical Almelo The Nether-lands 2006

[34] H Putz and K Brandenburg Pearsonrsquos Crystal Data CrystalStructure Database for Inorganic Compounds CD-ROM Soft-ware Version 13

[35] P Ghosh and M Medraj ldquoThermodynamic calculation of theMg-Mn-Zn and Mg-Mn-Ce systems and re-optimization oftheir constitutive binariesrdquo Calphad Computer Coupling ofPhase Diagrams andThermochemistry vol 41 pp 89ndash107 2013

[36] A Prince Alloy Phase Equilibria Elsevier Amsterdam TheNetherland 1966

[37] L Y H John ldquoSchreinemakers rule as applied to non-degenerate ternary systemsrdquoThe Journal of Young Investigatorsvol 19 no 11 2009

Submit your manuscripts athttpwwwhindawicom

ScientificaHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CorrosionInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Polymer ScienceInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CeramicsJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CompositesJournal of

NanoparticlesJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

International Journal of

Biomaterials

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

NanoscienceJournal of

TextilesHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Journal of

NanotechnologyHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

CrystallographyJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CoatingsJournal of

Advances in

Materials Science and EngineeringHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Smart Materials Research

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

MetallurgyJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

BioMed Research International

MaterialsJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Nano

materials

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal ofNanomaterials

Submit your manuscripts athttpwwwhindawicom

ScientificaHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CorrosionInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Polymer ScienceInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CeramicsJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CompositesJournal of

NanoparticlesJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

International Journal of

Biomaterials

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

NanoscienceJournal of

TextilesHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Journal of

NanotechnologyHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

CrystallographyJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CoatingsJournal of

Advances in

Materials Science and EngineeringHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Smart Materials Research

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

MetallurgyJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

BioMed Research International

MaterialsJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Nano

materials

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal ofNanomaterials