Upload
patel-ketan
View
227
Download
0
Embed Size (px)
Citation preview
8/13/2019 21386982 Note Chp 2 Material Science 281 Uitm Em110
1/74
MEC281 : MATERIALS SCIENCE
CHAPTER 2 :
PHASE DIAGRAM
Rasdi bin DeramanJabatan Kejuruteraan Mekanikal
UiTM Pulau Pinang
8/13/2019 21386982 Note Chp 2 Material Science 281 Uitm Em110
2/74
8/13/2019 21386982 Note Chp 2 Material Science 281 Uitm Em110
3/74
SOLIDIFICATION OF PURE METALS &ALLOYS
The solidii!"#io$ o %e#"ls "$d #hei "llo's is"$ i%(o#"$# i$d)s#i"l (o!ess*
No# o$l' do s#)!#)e "llo's s#"# +i#h #he
!"s#i$, o i$,o#s o (o!essi$, i$#oei$o!i$, -"s o s#)!#)"l sh"(e. -)# +he$" %e#"l is +elded " s%"ll (o#io$ o %e#"l $e"#he +eld %el#s "$d esolidiies*
PHASE DIAGRAM
8/13/2019 21386982 Note Chp 2 Material Science 281 Uitm Em110
4/74
A#e (o)i$, i$#o #he %old. #he %ol#e$
%e#"ls/"llo's !ool "$d solidi'*
Solidii!"#io$ is #he %os# i%(o#"$# (h"se
#"$so%"#io$ -e!")se %os# o %e#"ls/"llo's
)$de,o #his #"$so%"#io$ -eoe -e!o%i$,
)se)l (od)!#s*
Solidii!"#io$ i$0ol0e li)idsolid (h"se
#"$so%"#io$. e*, : !"s#i$, (o!ess*
The solidii!"#io$ (o!ess dies de(e$di$,
o$ +he#he #he %e#"l is " ()e ele%e$# o "$
"llo'*
8/13/2019 21386982 Note Chp 2 Material Science 281 Uitm Em110
5/74
I$ ,e$e"l #he solidii!"#io$ o %e#"ls o "llo's !"$-e di0ided i$#o #he ollo+i$, s#e(s:
i3 The o%"#io$ o $)!lei i$ #he %el#4$)!le"#io$3
ii3 The ,o+#h o $)!lei i$#o !'s#"liii3 The o%"#io$ o " ,"i$ s#)!#)e
Liquid
Nuclei
Liquid
Grain
Grain boundaries
Irregular grain
"3 -3 !3
Solidii!"#io$ Po!ess
8/13/2019 21386982 Note Chp 2 Material Science 281 Uitm Em110
6/74
*rmatin % the grain +nes
A# #he +"lls o #he %old. #he %ol#e$ %e#"ls/"llo's
!ools "(idl'* As " es)l#. #he !"s#i$, de0elo(s s%"lle)i"5ed ,"i$sd)e #o #he l",e #e%(* ,"die$# "# #he
s)"!e*
As !ooli$, !o$#i$)es. #he ,"i$s ,o+ i$ #he die!#io$
o((osi#e #o #he he"# lo+ +hee #he ,"i$s ,o+
i$+"dl' "s $eedles is 6$o+$ "s !ol)%$" ,"i$s*
8/13/2019 21386982 Note Chp 2 Material Science 281 Uitm Em110
7/74
For pure metals, columnar grains will stop to
grow until complete solidification has
occurred.
For alloys, further cooling of the molten alloy
will cause formation of l",e e)i"5ed,"i$s. showing segregation of alloying
components in the center of casting due to
the imbalance in composition between themetal that has solidified and the remaining
molten metal.
8/13/2019 21386982 Note Chp 2 Material Science 281 Uitm Em110
8/74
Figure : chematic illustration of two cast structures of metals solidified in a square mold:
!a" pure metals# !b" alloys
-3"3
S%"ll
e)i"5ed
7o$e
Col)%$"
,"i$s
L",e
e)i"5ed
7o$e
8/13/2019 21386982 Note Chp 2 Material Science 281 Uitm Em110
9/74
$ost metals are combined to form
alloy in order to impart specific
characteristic.
%n "llo' is a combination of two or
more elements !added impurity
atoms", at least one of which is a
metal.
&he addition of impurity atoms to a
metal will result in the formation of a
solid sol)#io$which composed of
sol0e$#!host atoms" and sol)#e!alloying elements".
'.g : teel(cast iron !iron base
alloys", bron)e(brass !copper base
alloys", %l alloys, Ni base alloys, $gbase alloys, &i alloys.
METALLIC SOLID SOLUTION
8/13/2019 21386982 Note Chp 2 Material Science 281 Uitm Em110
10/74
T+o #'(es o solid sol)#io$s:
i* I$#es#i#i"l Solid Sol)#io$
ii* S)-s#i#)#io$"l Solid Sol)#io$
Mos# e$,i$eei$, %e#"ls "e !o%-i$ed
+i#h o#he %e#"ls o $o$%e#"ls #o (o0ide
i$!e"sed s#e$,#h. hi,he !oosio$
esis#"$!e o #he desied (o(e#ies*
The si%(les# #'(e o "llo' is " %i5#)e o#+o sol)#io$ +hi!h is !o$sis#s o #+o o
%oe ele%e$#s "#o%i!"ll' dis(esed i$ "
si$,le (h"se s#)!#)e*
TYPES OF SOLI SOL!TIO"
8/13/2019 21386982 Note Chp 2 Material Science 281 Uitm Em110
11/74
E5"%(les o "#o%s #h"# !"$
o% I$#es#i#i"l Solid
Sol)#io$s d)e #o #hei s%"ll
si7e "e h'do,e$. !"-o$.
$i#o,e$. "$d o5',e$*
A solid sol)#io$ o%ed i$ +hi!h sol)#e "#o%s!"$ e$#e #he holes i$ #he sol0e$#"#o% l"##i!e*
The sol)#e "#o%s i# i$#o #he s("!es -e#+ee$
#he sol0e$# o ("e$# "#o%s*
I$#es#i#i"l Solid Sol)#io$s
8/13/2019 21386982 Note Chp 2 Material Science 281 Uitm Em110
12/74
The l"##i!e dis#o#io$ !e"#es " s#"i$ "lo$, #he sli( (l"$es "$d ,"i$s o #he %"#ei"l.
+hi!h es)l#s i$ #he i$!e"se o s#e$,#h "$d h"d$ess -e!")se i# %"6es "#o%-'
"#o% sli( "lo$, #hose (l"$es %oe dii!)l#*
i3 S)-s#i#)#io$"l solid sol)#io$ ii3 I$#es#i#i"l solid sol)#io$
Fi,)e : This is " s!he%"#i! ill)s#"#i$, ho+ #he l"##i!e is s#"i$ed -' #he "ddi#io$ o
s)-s#i#)#io$"l "$d i$#es#i#i"l sol)#e* No#i!e #he s#"i$ i$ #he l"##i!e #h"# #he sol)#e "#o%s
!")se*
8/13/2019 21386982 Note Chp 2 Material Science 281 Uitm Em110
13/74
A solid sol)#io$ i$ +hi!h sol)#e "#o%s o o$e ele%e$#s
!"$ e(l"!e #hose o sol0e$# "#o%s o "$o#he ele%e$#*
I# !"$ -e o%ed -' #+o ele%e$#s sol)#e "#o%s !"$
s)-s#i#)#e o ("e$# sol0e$# "#o%s i$ " !'s#"l l"##i!e*
The !'s#"l s#)!#)e o #he sol0e$# is )$!h"$,ed. -)##he l"##i!e %"' -e dis#o#ed -' #he (ese$# o #he
sol)#e "#o%s*
Fo e5"%(le. i$ " C)Ni solid sol)#io$ #he C) "#o%s
!"$ e(l"!e #he Ni "#o%s i$ #he solid sol)#io$ !'s#"ll"##i!e*
2*2*2 S)-s#i#)#io$"l Solid Sol)#io$s
8/13/2019 21386982 Note Chp 2 Material Science 281 Uitm Em110
14/74
This !o$i,)"#io$ !"$ -e #e$d #o o!!) +he$ #he "#o%s
do $o# die ,e"#l' i$ si7e "$d %)s# -e )i#e si%il" :
Less #h"$ "-o)# 19 diee$!e i$ "#o%i! "dii
The s"%e !'s#"l s#)!#)e
Si%il" ele!#o$e,"#i0i#' 4#he "-ili#' o #he "#o% #o
"##"!# "$ ele!#o$3
The s"%e 0"le$!e*
8/13/2019 21386982 Note Chp 2 Material Science 281 Uitm Em110
15/74
2* SOLUTION
;he$ #+o !o%(o$e$#s !o%-i$ed #he' !"$ ei#he e%"i$
se(""#e e$#i#ies o !o%-i$e #o o% " si$,le (h"se +hi!h
is eeed #o "s " sol)#io$* De,ee #o +hi!h #he #+o!o%(o$e$#s %i5 is eeed #o "s #he sol)-ili#'*
Sol)#io$s !"$ "lso o!!) i$ #he solid s#"#e "$d +i#h #he
s"%e "$,e o sol)-ili#' "s des!i-ed o li)ids*
E5"%(les: C) "$d Ni "e completelysol)-le
8/13/2019 21386982 Note Chp 2 Material Science 281 Uitm Em110
16/74
A (h"se di","% is " ,"(hi!"l e(ese$#"#io$ o #he (h"ses
(ese$#. !o%(osi#io$. "$d #e%(e"#)e "# e)ili-i)% o #he
s#)!#)e o "$ "llo' o !e"%i!s i$ +hi!h #he (h"ses "es#"-le* Ph"se Di","% %os# i%(o#"$# #ools "0"il"-le #o
%"#ei"ls s!ie$#is# "$d e$,i$ees*
2*>*1 ?i$"' Ph"se Di","%s
A -i$"' (h"se di","%s !o$sis# o #+o ele%e$#s i$
o$e "llo'* Thee "e #hee #'(e o (h"se di","%s:
i* Co%(le#e Solid Sol)#io$
ii* No Solid Sol)#io$
iii* Li%i#ed Solid Sol)#io$
2*> THE PHASE DIAGRAMS
8/13/2019 21386982 Note Chp 2 Material Science 281 Uitm Em110
17/74
2*>*2 ?i$"' Ph"se Di","%s o Co%(le#e Solid Sol)#io$
This (h"se di","% sho+s "$ isomorphous@s's#e% i$
+hi!h o$l' o$e solid (h"se o%s* @Isomorphicity %e"$s
h"0i$, s"%e !'s#"l s#)!#)e o !o%(le#e solid sol)-li#'
o "ll !o%(osi#io$*
The "llo' is solid o "ll
!o%(osi#io$ "# #e%(e"#)e
-elo+ T%.A
The "llo' is li)id o "ll
!o%(osi#io$ "# #e%(e"#)e
"-o0e T%.?
li)id)s li$e
Solid)s li$e
T%.A
T%.?
8/13/2019 21386982 Note Chp 2 Material Science 281 Uitm Em110
18/74
The ele%e$#s "e dissi%il" #h"# #hei sol)-ili#' i$ o#he
is $e"l' !"$ $e,li,i-le*
Li#uidus line
Solidus line
Temperature
$omposition
Eutectictemperature
Eutectic point
L
A % &
A % L & % L
A &
2*>* ?i$"' Ph"se Di","%s o No Solid Sol)#io$
The i,)e -elo+ sho+s ele%e$# A "$d ? !"$$o#
dissol0es +i#h e"!h o#he* The ele%e$#s "e o$l'
!o%(le#el' sol)-le i$ #he li)id s#"#e -)# !o%(le#el'
i$sol)-le i$ #he solid s#"#e*
8/13/2019 21386982 Note Chp 2 Material Science 281 Uitm Em110
19/74
The ele%e$#s "e dissi%il" #h"# #hei sol)-ili#' i$ o#he is
$e"l' !"$ $e,li,i-le*
Li#uidus line
Solidusline
Temperature
$omposition
Eutectic
temperature
Eutectic point
Li#uid, L
% L % L
A &
2*>*> ?i$"' Ph"se Di","%s o Li%i#ed Solid Sol)#io$
Solidusline
Sol'uslineSol'us
line
+
The i,)e -elo+ sho+s ele%e$# A "$d ? !"$$o# dissol0es
+i#h e"!h o#he* The ele%e$#s "e o$l' !o%(le#el' sol)-le i$
#he li)id s#"#e -)# !o%(le#el' i$sol)-le i$ #he solid s#"#e*
8/13/2019 21386982 Note Chp 2 Material Science 281 Uitm Em110
20/74
2* THE GI??S PHASE RULE
Ph"se di","% des!i-e #he%od'$"%i! e)ili-i)%
!o$di#io$* N)%-e o (h"ses i$ e)ili-i)% li%i#ed -'
#he%od'$"%i!s*
This is des!i-ed -' Gi--s (h"se )le:
" , % - # , n
p = number of phases presentf = number of degrees of freedom
(s#"#e 0"i"-les : Te%(e"#)e. Pess)e
"$d !o%(osi#io$3
c = no. of components
n = no. of noncompositional variables
4$ 1 o "llo'/!e"%i!. $ 2 o !o$de$s"#e3
8/13/2019 21386982 Note Chp 2 Material Science 281 Uitm Em110
21/74
E5"%(lesI!e+"#es#e"% : dis#i$!# (h"ses
gas
slidli$uid
Tem"erature
Pres
sur
e
T( T) T*
8/13/2019 21386982 Note Chp 2 Material Science 281 Uitm Em110
22/74
slid
li$uid
Tem"erature
Pres
sur
e
One phase two degrees of freedom
P(
P)
T( T) T*
8/13/2019 21386982 Note Chp 2 Material Science 281 Uitm Em110
23/74
slidli$ui
d
Tem"erature
Pres
sur
e
Two phases one degree of freedom
T( T)
P(P)
8/13/2019 21386982 Note Chp 2 Material Science 281 Uitm Em110
24/74
slidli$uid
Tem"erature
Pres
sur
e
Three phases zero degree offreedom
P.
T.
;he$ #he de,ee o eedo% is e)"l #o 7eo. i# is !"lled
i$0"i"$# (oi$#*
gas
8/13/2019 21386982 Note Chp 2 Material Science 281 Uitm Em110
25/74
Ph"se )le o -i$"' s's#e% . !2 4A "$d ?3
F P
A si$,le (h"se . P1 . F2
!o%(osi#io$ "$d #e%(e"#)e !"$ -e !h"$,ed
i$de(e$de$#l'
T+o(h"se %i5#)e F1
* "# " ,i0e$ #e%(. #he !o%(osi#io$ o #he li)id "$d solid
is i5ed . ,i0e$ -' #he li)id)s "$d solid)s li$e
8/13/2019 21386982 Note Chp 2 Material Science 281 Uitm Em110
26/74
2*B INTERPRETATION OF PHASE DIAGRAM ?Y USING
LEER RULES METHOD
A (h"se di","% ,i0es #he ollo+i$, i$o%"#io$:
The (h"se (ese$# 4solids "$d li)ids o !o%-i$"#io$s3
The !o%(osi#io$ 4!he%i!"l %"6e)(3 o #hese (h"ses
The "%o)$# o e"!h (h"se
2*B*1 The (h"se (ese$#
O$e )s# lo!"#es #he #e%(e"#)e = !o%(osi#io$ (oi$#
o$ #he di","% "$d $o#es #he (h"se4s3 +i#h +hi!h #he
!oes(o$di$, (h"se ield is l"-eled*
8/13/2019 21386982 Note Chp 2 Material Science 281 Uitm Em110
27/74
2*B*2 The !o%(osi#io$
i* D"+ #he #ie li$e "!oss #he #+o(h"se e,io$ "# #he#e%(* o #he "llo'*
ii* The i$#ese!#io$s o #he #ie li$e & (h"se -o)$d"ies o$
ei#he side "e $o#ed*
iii* D"+ #he (e(e$di!)l" li$e o% #hese i$#ese!#io$s #o#he hoi7o$#"l !o%(osi#io$ "5is.
8/13/2019 21386982 Note Chp 2 Material Science 281 Uitm Em110
28/74
2*B* De#e%i$"#io$ o Ph"se A%o)$#
Te%(e"#)e 12 C
Co%(osi#io$ +#9NiB +# 9 Ni
Ph"ses (ese$# Li)id
M"ss "!#io$ o . ; "$d
M"ss "!#io$ o Li)id. ;L
L
o
L
L
CC
CCW
SR
SW
=
+
=
The el"#i0e "%o)$#s o #he (h"ses (ese$# "# e)ili-i)%
!"$ -e de#e%i$ed -' )si$, Le0e R)le %e#hod*
8/13/2019 21386982 Note Chp 2 Material Science 281 Uitm Em110
29/74
E5"%(le: ?"sed o$ #he di","% -elo+. de#e%i$e #he (h"se (ese$#.
#he !he%i!"l !o%(osi#io$ "$d el"#i0e (h"se "%o)$# "# #he
!o%(osi#io$ "$d #e%(e"#)e +#9 Ni "$d 1 Ces(e!#i0el'*
Solution:
8/13/2019 21386982 Note Chp 2 Material Science 281 Uitm Em110
30/74
E5"%(le:
?"sed o$ #he di","% -elo+. de#e%i$e #he (h"se (ese$#.
#he !he%i!"l !o%(osi#io$ "$d el"#i0e (h"se "%o)$# "# #he
!o%(o* "$d #e%(* +#9 S$ "$d 2 C es(e!#i0el'*
Solution:
8/13/2019 21386982 Note Chp 2 Material Science 281 Uitm Em110
31/74
E5"%(le: ?"sed o$ #he di","% -elo+. de#e%i$e #he (h"se
(ese$#. #he !he%i!"l !o%(osi#io$ "$d el"#i0e (h"se
"%o)$# "# #he e)#e!#i! (oi$# "$d sli,h#l' -elo+ e)#e!#i!#e%(e"#)e*
Solution:
8/13/2019 21386982 Note Chp 2 Material Science 281 Uitm Em110
32/74
+'
E)#e!#i! #e%(* 4TE3 :
No li)id -elo+ TE
"$d o% 2 diee$#
solid (h"ses*
E)#e!#i! #e%(* 4TE3
"*6*"* #i(le (oi$#*
E)#e!#i! !o$!e$#"#io$ 4CE3 :
Mi$* %el#i$, #e%(* !o%(osi#io$ 4CE3Fi,)e : Co((esil0e (h"se di","%
8/13/2019 21386982 Note Chp 2 Material Science 281 Uitm Em110
33/74
Gradual solidification of the -% / -0 composition
Mi!os#)!#)"l de0elo(%e$# d)i$, slo+ !ooli$,
8/13/2019 21386982 Note Chp 2 Material Science 281 Uitm Em110
34/74
Fi,)e : P-S$ s's#e%
8/13/2019 21386982 Note Chp 2 Material Science 281 Uitm Em110
35/74
Cooling curve )se)l #ools o s#)d'i$, #he
solidii!"#io$ (o!ess*
I$ solidii!"#io$ o "llo'ed %e#"ls. #he #e%(* o(h"se !h"$,es +ill -e diee$# o e0e'!o%(osi#io$ (because alloy consists of 2 or more
metals).
The #e%(* & !o%(* o (h"se !h"$,es !"$ -e,"(hed so #h"# "ll (ossi-le !o%-i$"#io$ o #+o()e %e#"ls "e e(ese$#ed*
This +ill (od)!e " ,"(h 6$o+$ "s PHS!"I#$%+hi!h sho+s #he el"#io$shi( "%o$,#e%(*. !o%(* & (h"ses (ese$# i$ "llo' s's#e%*
COO/I01 CURVE DI21R2M
COO/I01 CURVE *OR
8/13/2019 21386982 Note Chp 2 Material Science 281 Uitm Em110
36/74
*r "ure metal3 the#ling #ur(es sh!hri+ntal thermalarrest at their%ree+es "ints'
Di%%erent #m"sitin!ill gi(e di%%erent#ling #ur(es'
The sl"e #hanges at/.45. et#'3 are#rres"nd t theli$uidus and slidus'
L1
S1
Freezingzone
COO/I01 CURVE *ORISOMORPHOUSBINARY
DI21R2M1
8/13/2019 21386982 Note Chp 2 Material Science 281 Uitm Em110
37/74
e)ili-i)% (h"se di","%
A -i$"' iso%o(ho)s !ooli$, !)0es
8/13/2019 21386982 Note Chp 2 Material Science 281 Uitm Em110
38/74
Li)id Solid
Li)id
Solid
A ? C D
$OOLI"+ $!-E FO EUTECTICBINARYIA+A.
Solid
Li)id
2 8 ARIOUS TYPE OF ALLOY TRANSFORMATIONS
8/13/2019 21386982 Note Chp 2 Material Science 281 Uitm Em110
39/74
2*8*1 E)#e!#i!e T"$so%"#io$s
L +cooling
The e)#e!#i! #"$so%"#io$ o!!)s "# 18oC "# " !o%(* o B19 S$*
+
I$ #he e)#e!#i! e"!#io$ #he si$,le li)id (h"se #"$so%s
si%)l#"$eo)sl' i$#o #he #+o solid (h"ses o% "# #he e)#e!#i!
#e%(e"#)e* The e)#e!#i! e"!#io$ !"$ -e +i##e$ "s.
2*8 ARIOUS TYPE OF ALLOY TRANSFORMATIONS
FOR ?INARY PHASE DIAGRAMS
8/13/2019 21386982 Note Chp 2 Material Science 281 Uitm Em110
40/74
11oC
2*8*2 Pei#e!#i! "llo' #"$so%"#io$s
I$ #he (ei#e!#i! e"!#io$ " li)id (h"se e"!#s +i#h "
solid (h"se #o o% " $e+ "$d diee$# solid (h"se*
The (ei#e!#i! e"!#io$ !"$ -e +i##e$ "s.Li)id. L
Fo e5"%(le.
L (5.4% Ni) + (4.0% Ni) (4.3% Ni) cooling
8/13/2019 21386982 Note Chp 2 Material Science 281 Uitm Em110
41/74
2*8* Mo$o#e!#i! #"$so%"#io$
/. , /
6
The %o$o#e!#i! e"!#io$ o!!)s +hee "# " s(e!ii! #e%(*
#he li)id sol)#io$ o !o%(osi#io$ L1#"$so%s i$#o " solid
(h"se "$d " se!o$d li)id o !o%(osi#io$ L2+hi!h isdiee$# o% L
1* The e)"#io$ e"ds:
cooling
The %o$o#e!#i!
#"$so%"#io$ o!!)s
"# oC "# " !o%(*o
B9 P-* Fo% oC
do+$. (o!6e#s o le"di!h %el# "e e$#"((ed
i$ #he solid C) "l(h"
(h"se*
2 8 > E)#e!#oid #"$so%"#io$
8/13/2019 21386982 Note Chp 2 Material Science 281 Uitm Em110
42/74
The e)#e!#oid e"!#io$ is si%il" #o #he e)#e!#i! e"!#io$ i$ #h"#
o$e (h"se de!o%(ose i$#o #+o (h"ses )(o$ !ooli$,*
A e)#e!#oid e"!#io$ +hee #he si$,le solid (h"se #"$so%s i$#o
solid (h"ses h"0i$, diee$# !o%(osi#io$s o% #he (h"se*
The e)#e!#i! e"!#io$ !"$ -e +i##e$ "s.
2*8*> E)#e!#oid #"$so%"#io$
+ cooling
A i$ (ei#e!#oid e"!#io$ #he #+o solid (h"ses #"$so% i$#o #he
si$,le solid (h"se* The (ei#e!#oid e"!#io$ !"$ -e +i##e$ "s.
2*8* Pei#e!#oid #"$so%"#io$
+ cooling
2 8 B Mo$o#e!#oid #"$so%"#io$
8/13/2019 21386982 Note Chp 2 Material Science 281 Uitm Em110
43/74
2*8*B Mo$o#e!#oid #"$so%"#io$
+ 21cooling
The %o$o#e!#oid e"!#io$ o!!)s +hee "# " s(e!ii! #e%(*
#he solid sol)#io$ o !o%(osi#io$ #"$so%s i$#o #he
#+o solid (h"ses * The e)"#io$ e"ds:
1
The #"$so%"#io$ o " E)#e!#i!. Pei#e!#i! "$d Mo$o#e!#i!
is !o$side "s #he #"$so%"#io$ o% li&uid#o solid phase.
;hile #he #"$so%"#io$ o " E)#e!#oid. Pei#e!#oid "$d
Mo$o#e!#oid is !o$side "s #he #"$so%"#io$ o% solid
#o solid phase.
2 INARIANT REACTIONS
8/13/2019 21386982 Note Chp 2 Material Science 281 Uitm Em110
44/74
2* INARIANT REACTIONS
J I$0"i"$# e"!#io$s "e o)$d i$(h"se di","%s o %"$' -i$"'
"llo's* A$ "llo' %"' h"0e o$l'
o$e i$0"i"$# e"!#io$ 4 e*,* P-
S$3 o h"0e %"$' i$0"i"$#
e"!#io$s de(e$di$, o$!o$!e$#"#io$ "$d #e%(e"#)e
4see e$,i$eei$, "llo's3*
I$0"i"$# e"!#io$s "e "l+"'s
de#e%i$ed i$ " $ei,h-ohood o#he #i(le (oi$# #h"# (i$s #he
i$0"i"$# e"!#io$* A!!odi$, #o
Gi--s (h"se )le #hee is 7eo
de,ees o eedo% "# #hese
e"!#io$ (oi$#s*
;he$ #he de,ee o eedo% is e)"l #o 7eo. #he e"!#io$ is
!"lled i$0"i"$# e"!#io$*
8/13/2019 21386982 Note Chp 2 Material Science 281 Uitm Em110
45/74
'1%$2L'
Find the peritectic and eutectoid reactions in the +u*3n
system4
8/13/2019 21386982 Note Chp 2 Material Science 281 Uitm Em110
46/74
TUTORI2/
&ismuth /melting point )0(1$2 and cadmium /meltingpoint *)(1$2 are assumed to be completel3 soluble inthe li#uid state and completel3 insoluble in solid
state4 The3 form a eutectic at (551$ containing 56 7cadmium4
ra8 the e#uilibrium diagram to scale on a piece ofgraph paper labeling all points, lines and areas4
For an allo3 containing 067 cadmium,
etermine the temperature of initial and finalsolidification4
etermine the chemical composition and relati'eamounts of phases present at a temperature of)661$4
S9etch the microstructure at room temperature4 ra8 the cooling cur'e4
OCT 6778
8/13/2019 21386982 Note Chp 2 Material Science 281 Uitm Em110
47/74
OCT 6778The cooling cur'es obtained 8hen t8o puremetals and se'eral of their allo3s 8ere cooled
from the li#uid phase are sho8n in figurebelo84
8/13/2019 21386982 Note Chp 2 Material Science 281 Uitm Em110
48/74
a2ra8 the phase diagram for the allo3 s3stemto scale on a piece of graph paper and label
all points, lines and areas4b2 For an allo3 containing 56 8t7A,
determine the li#uidus temperature, solidustemperature and freeing range of the allo34
c2$onsider an allo3 containing (6 8t7A4uring solidification, determine compositionof the first solid to form4
d2For an allo3 containing 068t7 A, determinethe chemical composition and relati'eamount of phases present at ;661$4
T bl . 7 h t t % th
8/13/2019 21386982 Note Chp 2 Material Science 281 Uitm Em110
49/74
Table .'7 sh!s tem"eratures % thebeginning and ending % the slidi%i#atin%r 1ermanium45ili#n s&stem' Cnstru#t
a "hase diagram t s#ale n a "ie#e %gra"h "a"er labeling all "ints3 lines andareas'
8/13/2019 21386982 Note Chp 2 Material Science 281 Uitm Em110
50/74
iii' Des#ribe the slidi%i#atin "r#ess% a 87!t95i
and determine its #hemi#al#m"sitins and relati(e amunts% "hases "resent at a tem"erature% .6:7;C'
iv. Draw the cooling curve for the 40wt%Si alloy.
v. Descrie the soli!ification "rocess.
#or an alloy containing 40wt%$e which is coole!
fro li&ui! "hase to roo te"erature' !eterine
i. the co"osition of the first li&ui! soli!ifie!.
ii. the co"osition of the last li&ui! soli!ifie!.
M2R 6778
8/13/2019 21386982 Note Chp 2 Material Science 281 Uitm Em110
51/74
M2R 6778A h3pothetical A
8/13/2019 21386982 Note Chp 2 Material Science 281 Uitm Em110
52/74
OCT 677Cnt''?
3poeutectoid plain carbon steel:If a sampleof 6457 $ is heated up to >666$, it gets
austenitied, 4 Further cooling gi'es rise to G and pearlite46earlite
5l! Cling % Plain Carbn 5teel
8/13/2019 21386982 Note Chp 2 Material Science 281 Uitm Em110
62/74
#2
g>Cnt''?
&"ereute#tid "lain #arbn steel=I% a.'69 C sam"le is heated u" t :77C and
held %r su%%i#ient time3 it entirel& getsausteniti+ed'
*urther #ling results results in
eute#tid #ementiteand "earlite'
* ti % lit
8/13/2019 21386982 Note Chp 2 Material Science 281 Uitm Em110
63/74
#'
*rmatin % "earlite T!4dimensinal mr"hlg& % "earlite3 a""arentl&
#nsisting % alternating la&ers % #ementite and %errite'
& 7hree!iensional analogy to theor"hology of "earlite' i.e. thecaage re"resents a single crystal
of "earlite' an! the water in theuc8et the single crystal of ferrite.
9 h f i l h f
8/13/2019 21386982 Note Chp 2 Material Science 281 Uitm Em110
64/74
#"
Eg 6: S9etch of microstructural changes for asteel containing 645 7 $ as it is cooled from8ithin the austenite phase region to belo8eutectoid temp4
5O/UTIO0=
/Ans: pearlite =(72
8/13/2019 21386982 Note Chp 2 Material Science 281 Uitm Em110
65/74
#!
E(lutin %Mi#rstru#ture
Eu#te#tid
YPOE!TE$TOI STEEL
8/13/2019 21386982 Note Chp 2 Material Science 281 Uitm Em110
66/74
##
/Fe
8/13/2019 21386982 Note Chp 2 Material Science 281 Uitm Em110
67/74
#$
/Fe
8/13/2019 21386982 Note Chp 2 Material Science 281 Uitm Em110
68/74
#8
8/13/2019 21386982 Note Chp 2 Material Science 281 Uitm Em110
69/74
car3on steel alloy containing 0' wt% C when cooled
4ust 3elow eutectoid temperature le5el etermine6
a) 7he relati5e amount of proeutectoid ferrite form.
3) 7he relati5e amount of eutectoid ferrite form.
c) (ketch the microstructure of item a) and 3)
respecti5ely
. )66=
8/13/2019 21386982 Note Chp 2 Material Science 281 Uitm Em110
70/74
$0
.ar )66=
Jith the aid of a neat s9etch, describe the
microstructural changes 8hich ta9e place8hen a (4( 8t7 plain carbon steel is slo8l3cooled from the austenite region ust abo'ethe upper critical temperature line4
(ep 2001
car3on steel alloy containing 0! wt% C when cooled
from the austenite region crosses the ' line escri3ewith neat sketches the microstructural changes that take
place during the slow cooling of this steel from the
austenite region
ECample*
8/13/2019 21386982 Note Chp 2 Material Science 281 Uitm Em110
71/74
$1
*4
A 64)=7 $ h3poeutectoid plain=61$ to a temp4 ust slightl3 belo80)01$4 $alculate:
/a2 the 8eight percent proeutectoid ferrite in the steel4
/b2 the 8eight percent eutectoid ferrite and 8eight percenteutectoid cementite in the steel4
00% C hypereutectoid plaincar3on steel is slowly
cooled from 009C to a temperature 4ust slightly a3o5e
$2$9C Calculate the weight percent proeutectoid
cementite and weight percent austenite present in the
steel:;ample "
8/13/2019 21386982 Note Chp 2 Material Science 281 Uitm Em110
72/74
$2
ECample=4
What is the Car3on concentration of an ironcar3on alloyfor which the relati5e amount fraction) of total ferrite is
0"