MMT Manual

8/12/2019 MMT Manual

1/53

Metallography and Materials Testing Lab

Technical data:

Maximum Impact Energy of pendulum = 300 Joules

Minimum value of scale graduation = 2 Joules

Distance between supports = 0 mm

!ngle of test piece supports = "0#

!ngle of inclination of supports = 0#

Maximum widt$ of t$e stri%er = &0 ' &( mm

!ngle of stri%ing edge = 30#

)eig$t of t$e mac$ine = &* +g ,!pprox-.

Observation:

&. Material of t$e given specimen =

2. Initial Energy = Joules-

3. )idt$ of t$e specimen/ b = mm-

. Dept$ of t$e specimen below t$e notc$/ d = mm-

Specimen:

55

27,5

10

10

452

Department of Mechanical Engineering SSE Mukka 1

LIST O !"#TS

&- ase wit$ specimen support fitted

2- 1olumn

3- endulum pipe

- endulum ammer

*- 4tri%er for 1$arpy test

5- 6uard

7820-9atc$ for 1$arpy 8 I:od test

(822- 9ever to release t$e pendulum&0- Dial

&&- ;eading pointer

&2- ra%e for pendulum

&3- ointer 1arrier

&- 4pecimen support

&*8&5- 9atc$ing tube for 1$arpy 8 I:od test

&7- 4tri%er for I:od test

23- earing $ousing

30- endulum s$aft


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1$ %&"#!' I(!"%T T)ST

"im:


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%alc*lation

&. !rea of cross section of t$e specimen below t$e notc$/ a = b x d

= mm2

2. Energy absorbed by t$e specimen for failure/ % = Joules-

3. Impact strengt$ = % 8 a

= Joules 8 mm2



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!reca*tions to be ta-en:

&- obody s$ould stand wit$in t$e range of t$e swing of t$e pendulum-

2- 9oc% t$e pendulum w$ile placing t$e specimen-

3- 4pecimen s$ould be placed carefully/ considering t$e correct position of t$e @ notc$/

unless stri%er may be damaged-

- endulum bra%es s$ould not be applied w$en t$e pendulum is returning-

#es*lt: Impact strengt$ of a given specimen = Joules 8 mm2



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Specimen:

10

10

27,5

452

75

Technical data:

Maximum Impact Energy of pendulum = &5( Joules

Distance between base of specimen notc$ ,or top or grips. and t$e point of specimen $it

by

t$e $ammer = 22 mm F 0-*

!ngle of stri%ing edge = 7*# F

!ngle of rise of t$e pendulum = &3*#

Observation:

&. Initial Energy = Joules-

2. )idt$ of t$e specimen/ b = mm-3. Dept$ of t$e specimen below t$e notc$/ d = mm-

%alc*lation:

& -!rea of t$e specimen below t$e notc$/ a = b x d

= mm2

2- Energy absorbed by t$e specimen for failure/ % = Joules

3- Impact value = % 8 a

= Joules 8 mm2



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2$ I.O/ I(!"%T T)ST

"im:


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#oc-ell &ardness Testin (achine

Sl o$ (aterial(aor Load

in -Indenter Scale

& ard 4teel &*0 Diamond 1one &20# 1

2 Mild 4teel &00 &-*(mm dia all Indenter

3 !luminium &00 &-*(mm dia all Indenter

rass &00 &-*(mm dia all Indenter

* 1opper &00 &-*(mm dia all Indenter



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3$ #O%)LL &"#/)SS T)ST

"im:


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- efore applying t$e minor load/ c$ec% t$e position of t$e lever w$ic$ is used to apply t$e

maCor load- It must be in t$e wit$drawal position-

#es*lt: ;oc%well $ardness number for t$e given specimen =



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Observations 6 %alc*lations:

Sl

,o$(aterial

Load !

in 47

/iaonal lenth in mm 8/9&,

/1 /2 "verae /

& Mild steel 30

2 1opper 20

3 rass 20

!luminium &0

= 9oad 8 !rea of impression = 8 D28sin , 82.

= 2 sin , 82. 8 D2

= &-(* 8 D2

-


)$ere K= &35

= 9oad in +gf

D = Diagonal lengt$


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4$ 9I%)#S &"#/)SS T)ST"im:

= &-(* 8 D2

)$ere/ = 9oad in +gf/

D= Diagonal lengt$ in mm-

#es*lt: ic%ers $ardness number of a given specimen =



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Tab*lar %ol*mn:

Diameter of t$e indenter D = mm

T+pe o7material Trial ,o$

orce

"pplied:!; 417

Indentati

450

Observations and Tab*lations:

&-


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>a$ T)SIOT)ST O (IL/ ST))L

"imL

&-


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5- 4tart t$e


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%alc*lations:

&- Initial cross sectional area ,!i. = Odi2 8 = mm2-

2- Ginal cross sectional area ,!f. = Odf2 8 = mm2-

3- ercentage reduction in area = P,!i@ !f.8 !iQ x &00

=

- ercentage Elongation = P,9f @ 9i.89iQ x &00

=

*- Nield 4tress = Nield 9oad 8 Initial !rea = Gy8 !i

= %8mm2

5- ltimate 4tress = ltimate load 8 Initial !rea = Gu8 !i

= %8mm2

7- rea%ing 4tress = rea%ing load 8 Initial !rea = Gb8 !i

= %8mm2

(- Modulus of Elasticity = 4lope x P9i8 !iQ

)$ere/ slope = DN8DR/ found out by t$e grap$

= %8mm2

)Btension in mm

Loadin-,

Y- Yield point

U- Ultimate load

B- Breaking load

U

B

Loadin-,

)Btensometer readin

in divisions

Y



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(- !s t$e yield point is approac$ed t$e load reading remains constant wit$ slig$t

variations and pointer of extensometer and displacement readings moves very rapidly-

ote down t$e yield point reading and remove extensometer from t$e specimen-

"- Increase t$e load graduallyH note down t$e c$ange in lengt$ from t$e scale readings-

&0- !fter t$e maximum load reac$es/ t$e load reading stops and starts decreasing- Ginally

specimen brea%s into two pieces- ote down t$e maximum load and brea%ing load-

&&- ;emove t$e specimen from


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Observations 6 Tab*lations:

&- 9east count of t$e vernier caliper = mm-

2- Initial Diameter of t$e specimen ,di. = mm-

3- Ginal Diameter of t$e specimen ,df. = mm-

,Diameter at t$e bulged portion.

- Initial lengt$ of t$e specimen 9i = mm-

*- Ginal lengt$ of t$e specimen 9f = mm-

%alc*lations:

&- Initial cross sectional area !i = Odi28

= mm2

2- Ginal cross sectional area !f = Odf28

= mm2

3- ercentage decrease in lengt$ = ,9i@ 9f. 8 9i x &00

=

- ercentage increase in area = ,!f@ !i. 8 !i x &00

=

*- 1ompressive stress = Maximum 1ompressive load 8 Initial !rea

= Gc8 !i

= % 8 mm2

5- Modulus of elasticity = 4lope x ,9i 8 !i.

)$ere slope = Dy 8Dx/ found out by t$e grap$

= % 8 mm2

Specimen:

d

L

Sl o$ Load in - /isplacement #eadin in mm

&

2

3

@@



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@

3

3*



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>b$ %O(!#)SSIO T)ST O %"ST I#O

"im: &-


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Specimen:

D

0l


4pan lengt$ 9 = mm

readt$ of t$e specimen = mm

)idt$ of t$e specimen D = mm

9engt$ of t$e specimen l = mm

Moment of Inertia I = = mm

ending Moment M = )$ere/ ) =Maximum load applied in %

=SSSSSSSSSSSSS % mm

Maximum ending stress f,s. = x =

C

=SSSSSSSSSSSSS %8mm2

(od*l*s o )lasticit+ D)E:

)e %now t$at/ = i-e- E = , . x )$ere/ = slope of t$e

9oad deflection curve-

=SSSSSSSSSSSSS %8 mm2

Specimen raph:

Loadin-,88

/isplacement in mm TT

Sl o$ Load in - /isplacement #eadin in mm



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&

2

3

@

@

&(

&"

20



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>c$ =)/I@ T)ST O (IL/ ST))L

"im:


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Specimen:

d = A/2

A 3A 5A min 3A

Gauge length

U

Observations 6 Tab*lations

&- 9east count of ernier 1aliper = mm-

2- Diameter of t$e specimen D = mm-

3- ;adius of t$e specimen ; = mm

- 9engt$ of t$e specimen 9 = mm-

%alc*lations:

&- olar moment of Inertia J = = mm

2- Modulus of rigidity 6 = w$ere/ is found out by t$e grap$-

= SSSSSSSS 8 mm2

3- Maximum s$ear stress f ,s. = )$ere/


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7$ TO#SIO T)ST O (IL/ ST))L

"im:


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ii. Maximum s$ear stress = 8 mm2

iii.


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9east 1ount of t$e ernier 1aliper = mm-

Sinle shear test on mild steel rod:

Diameter of t$e specimen d = mm

!rea of cross section !s = Od2 8 mm

Gailure load ) =

ltimate s$ear strengt$ = ) 8 !s 8mm2

/o*ble shear test on mild steel rod:

Diameter of t$e specimen d = mm

!rea of cross section !d = Od

2

8 mm

Gailure load ) =

ltimate s$ear strengt$ = ) 8 2 x !d 8mm2

Sinle shear test /o*ble shear test



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G$ S&)"# T)ST O (IL/ ST))L

"im:


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T)%&I%"L S!)%II%"TIOS:

&- Diameter of t$e specimens ,pins. L 3 to &0 mm

2- Disc L Diameter@ &00mm/ t$ic%ness@ 5 to ( mm

3-


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H$ )"# ST?/'

"imL &-

&0- ote down t$e corresponding wear frictional force readings-

&&- 1alculate sliding distance wear factor using formulae-

#es*lt:a. 4liding distance = mm



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b. )ear factor =



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Technical speciication:

&- Maximum bending moment L 200 %g cm

2- 9oad ,!dCustable. L @0 %g

3- ;otating speed of t$e specimen L 200 ;M

- Motor L 3/ 0-* / 2(00 ;M

Observations and %alc*lations:

ending moment ,Mb. = %g cm w$ere/ = load applied/

9= &0 cm-

ow/ ending stress = %g8cm2

)$ere/ X= 4ection modulus = for circular cross section-

fb = = w$ere/ d= 0-( cm

= %g8cm2

Specimen:

12,7

!" 1## !"



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10$ "TI@?) T)ST

"im:


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11$ &)"T T#)"T()T

"im:


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a $ardened steel structure/ i-e-/ martensite/ in t$is case- !fter being normali:ed/ suc$ steels will

be very $ard and must undergo $ig$ temperature tempering at **0@5*01 to enable t$em to be

mac$ined-

It is essential to note t$at two $eat treating operations/ normali:ing and $ig$ tempering/

re?uire less time t$an annealing-


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&ardenin Temperat*re

: %;70 750 7(0 (00 (20 (0 (50 ((0 "00

#oc-ell

:%;&ardness n*mber5* 5* 5* 5 53 52 52 5& 50



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/$ Temperin o steel:


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D-


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12$ (etalloraph+ or microscop+

"im: repare a specimen for metallograp$ic examination of engineering materials and to

study t$eir microstructure-

"pparat*s: olis$ing mac$ine/ emery papers/ etc$ing reagents and Metallurgical microscope-

Theor+: It consists of microscopic study of t$e structural c$aracteristics of a metal or an

alloy- It includes t$e study of t$e microstructure of metals/ t$e space arrangement of t$e atoms/

$eat treatment and examination by R@ rays-

S!)%I() ("I@ =' !OLIS&I@ !#O%)SS

&- lace a raw metal in t$e centre of t$e cold setting dye-

2- Mix a little cold setting powder wit$ t$e li?uid to get a certain consistency and pour

into t$e dye- )ait till t$e li?uid sets into a cylindrical structure-3- ow screw t$e lid of t$e dye onto t$e set structure and pus$ it out on t$e ot$er side-

- ow t$e specimen is ready for polis$ing-


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(etall*rical (icroscope:

It is t$e most important tool of t$e metallurgist from t$e scientific and tec$nical stand

points- It is possible to determine t$e grain si:e and t$e si:e/ s$ape and distribution of various

p$ases and inclusions w$ic$ $ave a great effect on t$e mec$anical properties of t$e metal-


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14$ ?LT#"SOI% L" /)T)%TO#

"im:


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15$ ("@)TI% %#"% /)T)%TO#

"im:


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9iva J*estions

&ardness Tests

&- Define $ardness-2- )$at are t$e uses of $ardness testsZ

3- Mention t$e types of $ardness tests/ wit$ brief explanation-

- )$at are t$e advantages of ;oc%well test over rinnelBs testZ

*- )$at are t$e advantages of ic%ers $ardness over rinnelBs or any ot$er testsZ

5- 1lassify $ow to find $ardness of any material $ow it depends on ot$er factorsZ

7- )$at is difference between $ardness and strengt$Z

(- Explain significance of different $ardness numbers wit$ example-

"- Differentiate between $ardness and toug$ness-

&0- )$at is an indenter and indentationZ

&&- )$at are types of $ardness measurementsZ

&2- Derive t$e expression for finding $ardness incase of rinnel $ardness number-&3- )$at are t$e different si:es of ball indenters in Z

&- )$at is t$e load ranges in different $ardness testing mac$inesZ

?niversal Testin (achine

&- )$at are t$e uses and different types of tests t$at can be performed on


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&(- )$at is meant by deformationZ ame different types of it-

&"- Explain single s$ear and double s$ear-

20- )$at is susceptibilityZ

2&- )$at is offset yield strengt$Z

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MMT Manual