LAPORAN PRAKTIKUM ILMU MATERIAL II
TOPIK
:Casting (Pengecoran (Pengecoran Logam)
KELOMPOK
: A2
WAKTU KTU PRAKT RAKTIK IKUM UM
: Sen Senin, in, 31 Oko Oko! !er 2"1# 2"1#
PEM$IM$I%&
: Mo' ogiarono, *rg, MKe+
Pen-+-n: No
Nama
NIM
. 1. 2. 3. 4. 5.
Maa Eka Rama*'ani Ra-'an+en $o+a/ino R-mokoi %aima-+ S'oi'a' a+ina Ia' A/i*ai 5a6ariana 5iriani
"21.11133""# "21.11133""0 "21.11133"" "21.11133"" "21.11133""4 "21.11133"1"
FAKULT FAKULTAS KEDOKTERAN KED OKTERAN GIGI UNIVERSITAS AIRLANGGA SURABAYA 2016 1. TUUAN
Ma'a Ma'a+i+ +i+7a 7a mam8mam8- meak meak-k -kan an 8en8en-an anga gan n oga ogam m cam8cam8-rr *eng *engan an !ena !enarr +era +era mam8- menganai+a 'a+i -angan !er*a+arkan 8engamaan
2. ALAT ! BA"AN 2.1 A#a$
a. ! c * e. f. g. h. i. j. k.
Glass lab Kom8or O9en Preheating furnace Aa -ang +enri/-ga *an crucible casting Blow torch Pen6e8i !-m!-ng -ang Pin+e keci Pi+a- mo*e *an 8i+a- maam Kai8er6angka +orong Sar-ng angan Master die
A
B
C
F
G
D
E 5
H
E Gam%a& 1. A) Pin+e, 8i+a- mo*e, glass lab $) Kom8or ;) O9en preheating furnace <) Aa -ang
+enri/-ga E) Blow torch 5) Sar-ng angan &) Pen6e8i !-m!-ng -ang =) >angka +orong
2.2 Ba'a( a Logam cam8-r Cu Alloy
3. )ARA KERA 3.1 A#a$ *a( %a'a( *+,+a-a(/ 1 Kom8or -n-k burn out +-*a' +ia8 *inaakan 2 Glass lab +-*a' *i!er+i'kan 3 Pin+e !e+ar, 8in+e keci, *an +ar-ng angan *i+e*iakan ? Preheating furnace (o9en) +-*a' *inaakan . Aa casting +enri/-ga +-*a' *aam kea*aan +ia8 *engan cara mem-ar engan 8em-ar
3 kai # Crucible casting *ima+-kkan ke*aam furnace 3.2 Burn out *a( preheating
1 Crucible former *ie8a+ *ari !-m!-ng -ang ang !eri+i !a'an anam 1
2 Maam *i!akar (burn out ) *engan cara : !-m!-ng -ang *ieakkan *i aa+ kom8or *engan 8o+i+i !agian *aar !-m!-ng -ang !era*a *iaa+ +e*angkan !agian crucible meng'a*a8 ke !a7a' (a8i) *engan +-*- ?. o 3 A8i kom8or *inaakan, !a'an anam -ang 8a*a !-m!-ng -ang *i!akar +am8ai 'a!i+ A*a +a- ciri -n-k mei'a 8em!akaran maam ang a*a *i*aam !-m!-ng -ang er6a*i ai- keika maam ea' er!akar, a8i kom8or akan e!i' mem!ara *an !e+ar ? Maam 'ar-+ *i8a+ikan 'a!i+ Pengecekan *iak-kan *engan cara glass lab *i--8kan 8a*a !agian crucible !-m!-ng -ang >ika eri'a !-ram karena a*a -a8 air ang menem8e 8a*a kaca arina maam !e-m er!akar 'a!i+, +e'ingga *iak-kan 8em!akaran kem!ai -n-k mem!akar maam 'ingga 'a!i+ %am-n, 6ika *iak-kan 8engecekan kem!ai +-*a' i*ak eri'a !-ram *an i*ak er*a8a -a8 air, !erari maam ea' er!akar 'a!i+ . O9en ( preheating furnace) *inaakan, kem-*ian !-m!-ng -ang *ima+-kkan *aam o9en ( preheating furnace) Pin- o9en *i--8 *an *i-ngg- 'ingga menca8ai +-'0."";
A
$
Gam%a& 2. A) Pro+e+ 8em!akaran maam *iaa+ kom8or
$) $-m!-ng -ang *ima+-kan ke*aam o9en preheating furnice 3.3 P(o&a( casting 1 Aa -ang +enri/-ga *i+ia8kan, *engan cara mem-ar engan 8em-ar +e!anak 3 kai,
kem-a*ian engan 8em-ar *ia'an *engan cara !aang 8ena'an *inaikkan 2 Crucible casting *i8ana+kan *engan blow torch ang *ieakkan 8a*a aa -ang +enri/-ga kem-*ian ogam ang akan *i-ang *ieakkan 8a*a ca7an -ang 3 Logam *i8ana+kan *engan a8i blowtorch, ona a8i ang *ig-nakan a*aa' ona re*-k+i ai- a8i *engan 7arna ke!ir-an 'ingga ogam men6a*i cair, ciri ogam ea' men6a*i cair *an aa +enri/-ga +ia8 -n-k *i8-ar a*aa' *engan menggearkan 8iringan 8a*a engan aa +enri/-ga, 6ika ogam er+e!- !ergenar *an +e8eri cair kem-*ian engan 8em-ar *iarik +e*iki, !aang 8ena'an *i-r-nkan kem-*ian engan 8em-ar *ie8a+ 'ingga !er8-ar
2
? &aa +enri/-ga akan men*orong ogam ma+-k ke *aam mould !-m!-ng -ang, 8-aran *i8eram!a *engan cara menekan 8oro+na mengg-nakan !aang ka- +am8ai engan 8em-ar !er'eni !er8-ar . $-m!-ng -ang *iam!i, *ieakkan *an *i*iamkan +e!enar a- *ima+-kkan ke *aam air (quenching ) agar 8erm-kaan 'a-+ *an kera+ # Seea' *ingin, 'a+i -angan *ike-arkan *ari *aam !-m!-ng -ang ang ea' me-nak, er6a*i *egran-a+i *an *i!er+i'kan *ari !a'an anam *i!a7a' air mengair 0 =a+i -angan *iam!i *an *i!eri an*a +e+-ai *engan an*a 7ak- 8enanaman =a+i -angan *i8a+ang 8a*a master die *an *ii'a marginal fit @na
A
$
;
<
Gam%a& 3. A) Pee!-ran ogam $) Pro+e+ casting mengg-nakan aa +enri/-ga
;) Mem8eram8a 8-aran mengg-nakan ka- <) Pro+e+ quenching
3
4. "ASIL PRAKTIKUM
Ta%# 1. =a+i 8rakik-m casting Mo-*
Margina +8ace
Saa8
Poro+ia+
$ini
Margina mem!-a
I
1,3. mm
Ti*ak a*a
Ti*ak a*a
A*a
Ti*ak
Ti*ak a*a
II
1,3 mm
A*a
Ti*ak a*a
A*a
Ti*ak
Ti*ak a*a
III (1)
1, mm
A*a
A*a
A*a
Ti*ak
A*a
III (2)
1, mm
Ti*ak a*a
Ti*ak a*a
A*a
Ti*ak
Ti*ak
4
5. PEMBA"ASAN
Casting aa- 8en-angan ogam *i ke*okeran gigi mer-8akan +-a- kegiaan a!oraorik mem!-a +e+-a- re+ora+i -ang *engan cara men-angkan ogam cair mengg-nakan aa -ang +enri/-ga agar ma+-k ke *aam rongga -ang aa- mo-* =a+i -angan 'ar-+ +e+-ai ( fit ) *engan die agar re+ora+i naman *i8akai oe' 8en*eria =a+i -angan *a8a !er-8a inlays onlays crowns bridges, *an frame !a+i+ gigi ir-an Ta'a8 a7a casting a*aa' *iak-kanna burn out maam 8a*a !-m!-ng -ang -n-k men*a8akan mould ang nani akan *ii+i oe' -angan ogam cair Seea' meak-kan burn out maam, *iak-kan 8engecekan *engan glass slab ang *ieakkan *i aa+ crucible -n-k mengecek a*a aa- i*akna +i+a maam *an -a8 air $ia glass slab men6a*i ker-' karena -a8 air, maka 'a er+e!- a*aa' an*a !a'7a ma+i' er*a8a +i+a maam ang !e-m 'a!i+ er!akar Ua8 air *a8a !era+a *ari maam *an *ari gypsum bonded ang mengaami 8emana+an Ua8 air ang *i*a8akan *ari gypsum bonded *a8a *i6ea+kan mea-i a'a8 setting reak+i *ari gypsum bonded +e!agai !erik-: 1 =emi'i*ra *icam8-r *engan air, er!en-k +-a- +-+8en+i cair *an *a8a *imani8-a+i 2 =emi'i*ra ar- er-+ 'ingga er!en-k ar-an ang 6en-' 3Lar-an 6en-' *ari 'emi'i*ra ini akan mem!en-k g-m8aan *i'i*ra ang *ien*a8kan ? Ter!en-k kri+a !ar-, reak+i er-+ !eran6- +am8ai +ee+ai Reak+i ang er6a*i *i aa+ erma+-k reak+i re!ersible *an ek+oerm *an *a8a *igam!arkan +e!agai !erik- (An-+a9ice et al 2"13, 'a 13@1?) (;aSO?)2=2O 3=2O → 2;aSO?2=2O 8ana+ >a*i, -a8 air *ari gypsum bonded *i*a8akan *ari kri+a ang mengan*-ng = 2O, ang mengaami 8emana+an +e'ingga !er-!a' men6a*i -a8 air Seain i-, +aa 8emana+an gypsum bonded 6-ga er*a8a reak+i ain ai- anara ka+i-m +-/a *an kar!on: ;aSO? ?; B ;aS ?;O Kar!on 8a*a reak+i er+e!- kem-ngkinan !era+a *ari re+i*- ang er+i+a +eea' memana+kan mo*e maam aa- m-ngkin *aam !en-k gra/i 8a*a !a'an anam -ang Reak+i e!i' an6- *a8a mem!e!a+kan +-/-r *iok+i*a Reak+i ini er6a*i 8a*a +-'- *i aa+ 0""C; (Mc;a!e D Wa+ 2"", 'a .") 3;aSO? ;aS B ?;aO ?SO 2
5
Preheating Furnace
Pemana+an in!estment mould 'ar-+ *iak-kan 8a*a ingka ang mem-ngkinkan -a8 *an ga+@ga+ ainna *i!e!a+kan an8a er6a*i reakan 8a*a ceakan >-ga 8ening !a'7a +-'- 8a*a +aa ceakan *i8ana+kan c-k-8 -n-k mem-ngkinkan ek+8an+i erma *an in9er+i er6a*i +era i*ak mengaami 8en-r-nan +-'- +ecara +igni/ikan +e!e-m casting *im-ai Se'ingga ceakan 'ar-+ *i8ana+kan +am8ai +ekiar 0."C; ere!i' *a'-- +e!e-m casting *im-ai (Mc ;a!e D Wa+ 2"", 'a ") Ke+eim!angan anara +-'- ogam cair *an em8era-r ceakan 8ening *aam 'a meng'a+ikan casting ang engka8 *an ak-ra *engan +r-k-r ang !aik Alloy 'ar-+ c-k-8 8ana+ -n-k mema+ikan !a'7a alloy +e8en-'na cair *an ea8 !era*a *iem8a +eama 8engecoran ke *aam ceakan, ea8i i*ak !oe' era- 8ana+ karena +-'- ang era- 8ana+ *a8a memic- er6a*ina ok+i*a+i aa- kri+ai+a+i +aa menca8ai rongga ceakan aamene!a!kan ker-+akan 8a*a *in*ing ceakan Tem8era-r ceakan 'ar-+ c-k-8 !e+ar -n-k mema+ikan ek+8an+i *ari ceakan *an -n-k mencega' kri+ai+a+i *ini ang *a8a mene!a!kan 8engi+ian alloy men6a*i i*ak 8en-' 8a*a ceakan, ea8i i*ak !aik -n-k kri+ai+a+i ang *i-n*a !egi- ama +e'ingga mem!en-k +r-k-r !-ir ang ka+ar (Mc ;a!e D Wa+ 2"", 8g ") Torch Melting *a( M,+( Casting S($&+a#
Me+in casting *i8-ar *-a +am8ai ima 8-aran (ergan-ng 8a*a me+in eren- *an kece8aan roa+i casting ang *iinginkan, *aam 8rakik-m ini *iak-kan +e!anak iga kai 8-aran) Un-k me+in casting , *aa *orong +enri/-ga ergan-ng 8a*a kece8aan roa+i 8a*a casting arm, 8an6ang engan *an kera8aan *ari alloy Alloy ang meee' oe' torch *aam ca7an keramik mengkia8 meeka 8a*a broken armF *ari me+in casting A8i torch *i'a+ikan *ari cam8-ran ga+ 8ro8ana *an -*ara, ga+ aam *an -*ara, acetylene *an ok+igen Broken armF mem8erce8a kece8aan roa+i a7a 8a*a crucible *an casting ring , +e'ingga meningkakan kece8aan inear ogam cair mema+-ki ceakan Seea' ogam ea' menca8ai +-'- casting *an casting ring ea' *i8ana+kan, me+in *ie8a+kan *an spring triggers m-ai !ergerak roa+i (An-+a9ice et al 2"13, 'a 22") Blow Torch
S-'- a8i +anga *i8engar-'i oe' +i/a ga+, 8ro8or+i ga+,*an -*ara 8a*a cam8-ran $agian *ari a8i *a8a *ii*eni/ika+i 8a*a "ona cone Cone 8an6ang 8erama ang !era+a ang+-ng *ari no""le a*aa' ona *i mana -*ara *an ga+ !ercam8-r +e!e-m 8em!akaran Gona ini i*ak meng'a+ikan 8ana+ Cone !erik-na a*aa' ona 'i6a- Gona ini mengeiingi inner cone *an *ikena +e!agai ona 8em!akaran
Gona ini 6ea+ meng'a+ikan ok+i*a+i *an 'ar-+ *i6a-'kan *ari alloy +eama 8ee!-ran Gona !erik-na a*aa' ona !ir- *an ereak *i -ar ona 'i6a- Gona ini a*aa' !agian er8ana+ *ari a8i, +e'ingga *ig-nakan 8a*a 8em!akaran alloy #uter cone (ona ok+i*a+i) a*aa' *aera' *i mana 8em!akaran er6a*i *engan ok+igen *i -*ara Gona ini i*ak *ig-nakan -n-k 8em!akaran alloy karena +eain +-'-na e!i' ren*a' *ari ona !ir-, ea8i 6-ga meng'a+ikan ok+i*a+i 8a*a alloy (An-+a9ice et al $"13, 'a 221) Seain i-, 8a*a 8ro+e+ 8emana+an ogam 8enga-ran naa a8i 6-ga 'ar-+ *i8er'aikan Blow torch 'ar-+ +e+-ai, i*ak !oe' o!erheating aa- underheating (k-rang 8emana+an) >ika 8emana+an era- ama maka *a8a mene!a!kan a*ana 8oro+ia+ 8a*a 'a+i ca+ing ogam (Po7er+ D Sakag-c'i 2"12, 'a .?1) >ika 8emana+an ogam k-rang e8a aa- a8i i*ak *ia-r *engan !aik *a8a mem!-ang 7ak- *an mer-+ak ogam mea-i ok+i*a+i ang !ere!i'an aa- ink-+i ga+ A-a 7a( $&8a*+ %+#a -$a&a( a#a$ ,($&+a# *+'($+a( m(*a*a9
Saa o8eraor mee8a+ !aang 8ena'an 8a*a aa +enri/-ga, aa er+e!- akan !er8-ar P-aran *ari aa +enri/-ga akan meng'a+ikan gaa ekan ang akan men*orong ao ogam ang ea' meee' -n-k ma+-k ke *aam mould A8a!ia 8-aran *ari aa er+e!- i!a@i!a *i'enikan, maka *a8a er6a*i kegagaan *aam casting Kegagaan ang *imak+-* *i +ini a*aa' alloy ogam i*ak akan *a8a ma+-k +ecara +em8-rna 8a*a mould +e'ingga 8a*a *aera' margin i*ak akan eri+i +em8-rna (An-+a9ice et al 2"13, 'a 22") Quenching
Pa*a +aa 8oro+ aa +enri/-ga !er'eni !er8-ar, !-m!-ng -ang kem-*ian *iam!i *an *ima+-kkan ke *aam air (quenching ) T-6-an *ari quenching a*aa': a Alloy ogam akan !era*a 8a*a kea*aan *i mana alloy er+e!- m-*a' -n-k *iak-kan burnishing polishing , *an +e!againa ! Saa air !erem- *engan !a'an in!estment ang 8ana+, akan im!- reak+i ang akan mene!a!kan !a'an in!estment e!i' m-*a' *i!er+i'kan *ari 'a+i alloy ogam (An-+a9ice et al 2"13, 'a222)
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Pa*a 8rakik-m ang kami ak-kan *i*a8akan !e!era8a 'a+i ang er*a8a 8a*a 'a+i -angan *ianarana a*aa' a*ana marginal space, !ini, 8oro+, +aa8, margina mem!-a +era *i+or+i Marginal space
Marginal space er*a8a 8a*a +em-a 'a+i casting 8rakik-m kami Pene!a! marginal space
a*aa' karena a*ana !ini 8a*a !agian *aam 'a+i casting Se'ingga a8a!ia
*ima+-kkan ke *aam die, 'a+i ceakan mem!en-k marginal space. Marginal space mene!a!kan 'a+i ceakan mengaami kei*ake8aan *engan die Kee8aan ak'ir %final fit& *ari casting *i8engar-'i oe' ke+eim!angan ek+8an+i *an konrak+i +eama 8em!en-kan 8ro+e*-r casting Per-!a'an *imen+i ini mei!akan 8en-+-an ogam ang +e'ar-+na *ikom8en+a+ikan oe' setting ek+8an+i, thermal ek+8an+i, *an in9er+i *ari !a'an anam -ang >ika er6a*i ke+aa'an eknik +e8eri k-rangna +-'- +aa 8emana+an !a'an anam *a8a mene!a!kan kom8en+a+i -n-k 8en-+-an ogam i*ak mema*ai (Mc ;a!e D Wa+ 2"", 'a 2@3) $e+arna marginal space *i8engar-'i oe' !e+ar kecina setting ek+8an+i *an ek+8an+i erma *ari !a'an anam S-a- !a'an anam 'ar-+ memiiki setting ek+8an+i *an erma ek+8an+i ang c-k-8 -n-k mengkom8en+a+i 8en-+-an ogam 8a*a +aa ogam men*ingin +eea' casting. 'etting ek+8an+i *an erma ek+8an+i *i8engar-'i !e+ar kecina 7:8 ra+io Semakin inggi 78 raio !a'an anam aa- +emakin cair kon+i+en+ina, setting ek+8an+i *an ek+8an+i erma ang er6a*i akan +emakin keci, +e'ingga meng'a+ikan ceakan alloy ang e!i' keci *i!an*ing -k-ran +e!enarna *an marginal space@na akan !e+ar Se!aikna 6ika 78 raiona keci *an kon+enra+ina kena, setting ek+8an+i *an ek+8an+i erma ang er6a*i akan +emakin !e+ar, +e'ingga meng'a+ikan ceakan alloy ang e!i' !e+ar +e'ingga marginal space(na akan keci (An-+a9ice et al 2"13, 'a 21#@210) B+($+#
Perm-kaan ang !er!ini er*a8a 8a*a 'am8ir +em-a 'a+i casting 8rakik-m kami $ini er6a*i 6ika er*a8a +i+a maeria !er!en-k !-a ang er+i+a *i 8erm-kaan ca+ing %am-n, ma+aa' er+e!- *a8a *iaa+i *engan 9ac--m in9e+ing $ini akan menam!a' 7ak- ang *i!--'kan -n-k meng'a+ikan ca+ing ang +e+-ai, nam-n 6ika ker-+akan er6a*i +anga 8ara', maka 'ar-+ *iak-kan re@ca+ca+ing -ang (Mc ;a!e D Wa+ 2"", 'a 2@3)
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Po&o,+$a,
Poro+ia+ er6a*i karena a*ana 8ro*-k+i ga+ ang ik- er6e!ak =a ini *i+e!a!kan oe' kei*akmam8-an -*ara *i *aam mo-* -n-k ke-ar mea-i 8ori@8ori gi8+-m !a'an anam -ang Poro+ia+ *a8a eri'a 8a*a 8erm-kaan casting aa- +aa casting +e*ang *aam 8ro+e+ finishing *an polishing $-iran H !-iran !a'an anam -ang aa- kooran ang er6a-' *ari +8r-e *a8a mene!a!kan casting men6a*i 8oro-+ Gaseous porosity pada casting !era+a *ari ga+ ang ar- *aam ee'an ogam Pa*a +aa 8en*inginan, ga+ ang er+era8 akan *ie8a+kan oe' ogam, ea8i er*a8a !e!era8a ga+ ang er6e!ak *aam alloy +aa alloy mengera+ =a ini *a8a *icega' *engan meng'in*ari 8emana+an !ere!i'an 8a*a alloy ma-8-n casting (o!erheating ) aa- meak-kan casting 8a*a r-angan minim ga+ aa- !acuum (Mc ;a!e 2"", 'a 2@3) Sa7a-
Saa8 *a8a er!en-k *i+e!a!kan karena 8ana+ ang era- inggi +e'ingga mene!a!kan kereakan 8a*a mo-* ;ea' aki!a reakan er+e!- kem-*ian *ii+i oe' ogam +e'ingga er!en-ka' +aa8 (Mc;a!e D Wa+ 2"", 'a 1) Pa*a 7ak- 8engecoran, ogam ang cair ini akan ma+-k ke cea@cea !agian ang brittle, +e'ingga er!en-ka' +aa8 8a*a ogam Se!aikna, +-'- ang era- ren*a' 6-ga *a8a mene!a!kan +aa8 er!en-k, a8a!ia ogam cair *engan +-'- inggi ma+-k ke *aam mould ang *ingin akan mene!a!kan thermal shock ang mengaki!akan mould men6a*i reak *an eri+i oe' ogam cair +e'ingga mem!en-k +aa8 Ma&+(a# mm%#a$
$agian margina mem!-a er6a*i karena 8em!-angan +i+a maam ang i*ak +em8-rna *ari *aam mould. >ika era- !anak 'a+i 8em!akaran ang eringga *i *aam mo-*, maka 8ori@8ori *ari !a'an anam er--8 maam +e'ingga -*ara i*ak *a8a ke-ar +e--'na >ika a*a cairan aa- 8arike maam ang eringga, maka konak *ari alloy *engan +i+a maam *a8a menim!-kan back pressure -n-k meng'aangi alloy ma+-k ke *aam mould Kegagaan ini eri'a !er-8a e8i ang mem!-a (Ann-+a9ice et al 2"13, 'a 220@22) D+,$o&,+
+aa +oi*i/ika+i, +anga 8ening -n-k meng'in*ari +'rinkage *an ek+8an+i aki!a *ari 8er-!a'an +-'- (Ann-+a9ice et al 2"13, 'a 144)
6. KESIMPULAN
Pem!-aan re+ora+i ang ak-ra *a8a mengg-nakan 8ro+e+ casting Ta'a8an 8ro+e+ casting er*iri *ari 8ro+e+ burn out (8em!akaran maam), preheating (memana+kan !-m!-ng -ang *i*aam preheating furnace), *an casting *engan aa +enri/-ga E/ek ang *a8a er6a*i ai-: marginal fit ang i*ak +e+-ai +e'ingga er!en-k marginal space, !ini, +aa8, 8oro-+ *an *i+or+i
:. DAFTAR PUSTAKA
An-+a9ice, K >, S'en, ;, D Ra7+, = R 2"13. Phillips) 'cience of *ental Materials 12 ' e* Mi++o-ri: E+e9ier Sa-n*er+ 'a 13@1?, 144, 21#@210, 22"@222, 220@22 Mc;a!e, > 5 D Wa+, AW& 2"" Applied *ental Materials 4 ' e* A-+raia: $ack7e P-!i+'ing L* 'a .", "@3 Sakag-c'i RL, Po7er >M, 2"12. Craig)s +estorati!e *ental Materials 13 e* P'ia*e8'ia : Mo+! E+e9ier 8 .?1
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