Cov txheej txheem casting kev ua tau zoo ntawm aluminium alloys feem ntau nkag siab tias yog kev sib xyaw ntawm cov khoom uas tseem ceeb tshaj plaws thaum lub sij hawm ntim pwm, crystallization, thiab txias txheej txheem. Fluidity, shrinkage, huab cua nruj, casting kev nyuaj siab, cua nqus.
1. Kev ua si
Kev ua ub no hais txog lub peev xwm ntawm cov kua alloy los sau cov pwm. Qhov loj ntawm qhov kev ua si txiav txim siab seb cov alloys tuaj yeem tsim cov castings loj. Eutectic alloys hauv aluminium alloys nthuav tawm cov haujlwm zoo tshaj plaws.
Muaj ntau yam cuam tshuam rau kev ua ub no, qhov tseem ceeb yog tus kheej, qhov kub thiab txias, thiab muaj cov khoom siv ntawm cov hlau oxides, cov khoom siv hlau, thiab lwm yam kuab paug hauv cov kua alloy. Txawm li cas los xij, qhov tseem ceeb ntawm sab nraud yog qhov roughness ntawm qhov kub thiab txias (feem ntau hu ua lub taub hau pouring).
Hauv kev tsim khoom tiag tiag, nyob rau hauv ib puag ncig uas cov hlau tau txiav txim siab, ntxiv rau kev ntxiv dag zog rau cov txheej txheem smelting (qhov tseem ceeb thiab slag tshem tawm), nws tseem yuav tsum tau txhim kho cov txheej txheem casting (xuab zeb pwm permeability, hlau pwm tso pa roj, thiab kub) , thiab txhim kho lub pouring kub yam tsis muaj kev cuam tshuam qhov zoo ntawm cov casting, kom ntseeg tau cov kev ua ntawm lub alloy.
2. Kev cog lus
Shrinkage yog ib qho ntawm cov yam ntxwv tseem ceeb ntawm cam khwb cia aluminium alloys. Feem ntau hais lus, cov alloys tuaj yeem muab faib ua peb theem los ntawm cov kua pouring mus rau solidification, thiab tom qab ntawd kom txias rau chav tsev kub, uas yog, kua shrinkage, solidification shrinkage, thiab khoom shrinkage. Lub shrinkage ntawm alloys muaj kev txiav txim siab rau qhov zoo ntawm castings, uas cuam tshuam rau qhov luaj li cas ntawm shrinkage kab noj hniav, tiam ntawm kev ntxhov siab, tsim cov kab nrib pleb, thiab kev hloov loj ntawm castings. Feem ntau, casting shrinkage muab faib ua ntim shrinkage thiab linear shrinkage. Hauv kev tsim cov tswv yim, linear shrinkage feem ntau yog siv los ntsuas qhov shrinkage ntawm alloys. Lub shrinkage ntawm aluminium alloys, feem ntau qhia raws li ib feem pua, yog hu ua shrinkage.
