I-Non-ferrous Metals Casting

Izinsimbi ezisansimbi zisetshenziswa kakhulu embonini yobunjiniyela ngenxa yokuphakama kwazo, ububanzi bezakhiwo zemishini kanye nezindleko eziphansi. Noma kunjalo, izinsimbi ezingenayo insimbi nazo zisetshenziswa ekusetshenzisweni okuhlukahlukene kwezakhiwo zazo ezithile uma kuqhathaniswa nama-alloys ayoniyo naphezu kwezindleko zazo ezivame kakhulu. Izakhiwo ezifiselekayo zemishini zingatholakala kulawa ma-alloys ngokuqiniswa komsebenzi, ukuqina kweminyaka, njll, kodwa hhayi ngezinqubo zokwelashwa ezijwayelekile zokushisa ezisetshenziselwa ama-alloys ayinsimbi. Ezinye zezinto eziyinhloko ezingenayo insimbi ezithakaselwayo yi-aluminium, ithusi, i-zinc, ne-magnesium

1. I-Aluminium

Kuwo wonke ama-alloys angeyona insimbi, i-aluminium nama-alloys ayo abaluleke kakhulu ngenxa yezakhiwo zawo ezinhle kakhulu. Ezinye zezakhiwo ze-aluminium ehlanzekile esetshenziselwa imboni yobunjiniyela yilezi:

• 1) I-thermal conductivity enhle kakhulu(0.53 cal/cm/C)
• 2) Ukusebenza kahle kukagesi (376 600/ohm/cm)
• 3) Ukuminyana okuphansi (2.7 g/cm)
• 4) Indawo encibilikayo ephansi (658C)
• I-5) Ukumelana nokugqwala okuhle kakhulu
• 6) Ayinabuthi.
• 7) Inokubonakala okuphezulu kakhulu (85 kuya ku-95%) kanye nokukhipha umoya okuphansi kakhulu (4 kuya ku-5%)
• I-8) Ithambile kakhulu futhi i-ductile ngenxa yalokho inezindawo ezinhle kakhulu zokukhiqiza.

Ezinye zezinhlelo zokusebenza lapho i-aluminium emsulwa ngokuvamile isetshenziswa khona kukukhondatha kagesi, izinto ezisetshenziswayo zama-radiator, amayunithi afaka umoya, izibonisi ezikhanyayo nezikhanyayo, kanye ne-foil nezinto zokupakisha.

Naphezu kwezinhlelo zokusebenza eziwusizo ezingenhla, i-aluminium ehlanzekile ayisetshenziswa kabanzi ngenxa yalezi zinkinga ezilandelayo:

• 1) Inamandla aphansi we-tensile (65 MPa) nokuqina (20 BHN)
• 2. Kunzima kakhulu ukushisela noma ukudayisa.

Izakhiwo zemishini ye-aluminium zingathuthukiswa kakhulu nge-alloying. Izakhi eziyinhloko ze-alloying ezisetshenziswayo yithusi, i-manganese, i-silicon, i-nickel ne-zinc.

I-Aluminium nethusi zakha ikhemikhali i-CuAl2. Ngaphezulu kwezinga lokushisa elingu-548 C lincibilika ngokuphelele ku-aluminium ewuketshezi. Uma lokhu kucinywa futhi kugugile ngokwenziwa (ukubamba isikhathi eside ku-100 - 150C), kutholakala ingxubevange eqinile. I-CuAl2, engagugi ayinaso isikhathi sokushona phansi isuka kusixazululo esiqinile se-aluminium nethusi futhi ngaleyo ndlela isesimweni esingazinzile(igcwele kakhulu ezingeni lokushisa legumbi). Inqubo yokuguga ibeka izinhlayiya ezinhle kakhulu ze-CuAl2, ezibangela ukuqiniswa kwe-alloy. Le nqubo ibizwa ngokuthi ukuqina kwesixazululo.

Ezinye izakhi ze-alloying ezisetshenziswayo kufika ku-7% we-magnesium, kufika ku-1. 5% manganese, kufika ku-13% we-silicon, kufika ku-2% we-nickel, kufika ku-5% we-zinc kanye ne-iron efika ku-1.5%. Ngaphandle kwalokhu, i-titanium, i-chromium ne-columbium ingase yengezwe ngamaphesenti amancane. Ukwakheka kwamanye ama-alloys ajwayelekile e-aluminium asetshenziswa ekubumbeni unomphela nasekubunjweni kwe-die kunikezwe kuThebula 2. 10 kanye nezicelo zazo. Izakhiwo zemishini ezilindelwe kulezi zinsiza ngemva kokuphonswa kwazo kusetshenziswa isikhunta esihlala njalo noma i-pressure die casting kukhonjiswe kuThebula 2.1

2. Ithusi

Ngokufanayo ne-aluminium, ithusi elihlanzekile nalo lithola ukusetshenziswa okubanzi ngenxa yezinto zalo ezilandelayo

• I-1) I-conductivity kagesi yethusi ehlanzekile iphakeme (5.8 x 105 /ohm/cm) ngendlela yayo emsulwa. Noma yikuphi ukungcola okuncane kwehlisa i-conductivity kakhulu. Isibonelo, i-0. 1% ye-phosphorus inciphisa ukuqhutshwa kwe-conductivity ngo-40%.
• 2) Ine-thermal conductivity ephezulu kakhulu (0. 92 cal/cm/C)
• 3) Kuyinsimbi enzima (i-gravity ethize 8.93)
• I-4) Ingahlanganiswa kalula ngokugqamisa
• 5) Imelana nokugqwala,
• 6) Inombala othokozisayo.

Ithusi elimsulwa lisetshenziswa ekwenzeni izintambo zikagesi, izinsimbi zamabhasi, izintambo zokudlulisela, amashubhu esiqandisi namapayipi.

Izakhiwo zemishini zethusi esimweni sayo esihlanzekile azilungile kakhulu. Ithambile futhi ibuthakathaka. Kungenziwa alloyed ngenzuzo ukuthuthukisa izakhiwo mechanical. Izakhi eziyinhloko ze-alloying ezisetshenziswayo yi-zinc, ithini, i-lead ne-phosphorus.

Ama-alloys ethusi ne-zinc abizwa ngokuthi ama-brasses. Ngokuqukethwe kwe-zinc kufika ku-39%, ithusi lakha isigaba esisodwa (α-phase) isakhiwo. Ama-alloys anjalo ane-ductility ephezulu. Umbala we-alloy uhlala ubomvu kuze kufike ku-zinc okuqukethwe kuka-20%, kodwa ngaphezu kwalokho uba phuzi. Ingxenye yesibili yesakhiwo ebizwa ngokuthi i-β-phase ivela phakathi kwama-39 kuya ku-46% we-zinc. Empeleni iyinhlanganisela ye-inter-metallic CuZn ebangela ukwanda kokuqina. Amandla ethusi aya ngokuya enyuka lapho amanani amancane e-manganese ne-nickel engezwa.

Ama-alloys ethusi anethayela abizwa ngokuthi ama-bronze. Ukuqina namandla ethusi kuyanda ngokuqhekeka kokuqukethwe kwethini. I-ductility nayo iyancishiswa ngokunyuka kwephesenti le-tin ngaphezu kuka-5. Uma i-aluminium nayo yengezwa (4 kuya ku-11%), ingxubevange ebizwa ngokuthi i-aluminium bronze, enokumelana nokugqwala okuphezulu kakhulu. Ama-bronze abiza kakhulu uma kuqhathaniswa nezithusi ngenxa yokuba khona kukathayela okuyinsimbi ebizayo.

3. Ezinye Izinsimbi Ezingeyona Insimbi

Zinc

I-Zinc isetshenziswa kakhulu kwezobunjiniyela ngenxa yezinga lokushisa eliphansi lokuncibilika (419.4 C) kanye nokumelana nokugqwala okuphezulu, okwandayo ngokuhlanzeka kwe-zinc. Ukumelana nokugqwala kubangelwa ukwakheka kwe-coating oxide evikelayo ebusweni. Izicelo eziyinhloko ze-zinc zisetshenziselwa ukwenza uthayela ukuze kuvikelwe insimbi ekugqwaleni, embonini yokunyathelisa kanye nasekufakweni kwensimbi.

Ububi be-zinc i-anisotropy enamandla eboniswa ngaphansi kwezimo ezikhubazekile, ukuntuleka kokuzinza kwe-dimensional ngaphansi kwezimo zokuguga, ukuncipha kwamandla omthelela emazingeni okushisa aphansi kanye nokuba sengozini kokugqwala kwe-inter-granular. Angeke isetshenziselwe isevisi engaphezu kwezinga lokushisa elingu-95.C ngoba izobangela ukwehla okukhulu kwamandla okuqina nobulukhuni.

Ukusetshenziswa kwayo kabanzi kuma-die castings kungenxa yokuthi kudinga umfutho ophansi, okuholela empilweni ephezulu yokufa uma kuqhathaniswa namanye ama-alloys e-die cast. Ngaphezu kwalokho, inokusebenza okuhle kakhulu. Isiphetho esitholwe nge-zinc diecasting ngokuvamile sanele ukugunyaza noma yikuphi ukucutshungulwa okuqhubekayo, ngaphandle kokususwa kwe-flash ekhona endizeni ehlukanisayo.

Magnesium

Ngenxa yesisindo sabo esilula namandla amahle emishini, ama-alloys e-magnesium asetshenziswa ngesivinini esikhulu kakhulu. Ngokuqina okufanayo, ama-alloys e-magnesium adinga kuphela i-37. 2% yesisindo sensimbi ye-C25 ngaleyo ndlela yonga isisindo. Izinto ezimbili eziyinhloko ezisetshenziswayo yi-aluminium ne-zinc. Ama-alloys e-Magnesium angaba isihlabathi, isikhunta esihlala njalo noma i-die cast. Izakhiwo zezingxenye zengxube ye-sand-cast magnesium alloy ziqhathaniswa nalezo ze-mold mold cast noma izingxenye ze-die-cast. Ama-alloys e-die-casting ngokuvamile ahlangene anokuqukethwe kwethusi okuphezulu ukuze avumele ukuthi enziwe ngezinsimbi zesibili ukunciphisa izindleko. Asetshenziselwa ukwenza amasondo emoto, amakesi e-crank, njll. Uma okuqukethwe kuphezulu, kuyanda amandla emishini yama-alloys enziwe nge-magnesium njengezingxenye ezigoqiwe nezifojiwe. Ama-alloys e-Magnesium angashiselwa kalula yizinqubo eziningi zendabuko zokushisela. Impahla ewusizo kakhulu ye-magnesium alloys wukusebenza kwayo okuphezulu. Zidinga kuphela u-15% wamandla omshini uma kuqhathaniswa nensimbi ephansi ye-carbon.