1. Kev kho mob thiab kev hloov kho
Inoculation kev kho mob yog hais txog cov txheej txheem ntawm kev ntxiv me me ntawm lwm yam khoom rau molten hlau thaum lub sij hawm solidification los txhawb nucleation thiab inhibit kev loj hlob, yog li refining nplej thiab txhim kho cov qauv. Conventionally, ntxiv additives rau cam khwb cia hlau yog hu ua inoculation kev kho mob; ntxiv additives rau cam khwb cia hlau thiab txhuas alloys yog termed hloov kho. Hauv cov ntsiab lus, kev kho mob inoculation feem ntau cuam tshuam rau nucleation, thaum kho kev hloov kho hloov pauv txoj kev loj hlob siv lead ua (inhibiting kev loj hlob), yog li cuam tshuam rau siv lead ua morphology.
Tam sim no, muaj ntau yam inoculants rau cam khwb cia hlau. Inoculants uas muaj barium, bismuth, thiab lub ntiaj teb tsis tshua muaj cov ntsiab lus tuaj yeem ua rau qeeb ntawm cov nyhuv inoculation. Inoculation txoj kev (piv txwv li, txoj kev ntxiv cov inoculant) feem ntau muaj xws li ladle inoculation, kwj inoculation, instantaneous inoculation (ntoo khob inoculation, cored hlau inoculation, kwj inoculation), thiab nyob rau hauv - pwm inoculation. Inoculation Instantaneous thiab nyob rau hauv - pwm inoculation tuaj yeem tiv thaiv inoculation fading, yuav tsum tau ib tug me me ntawm inoculant, thiab ua tau zoo inoculation cuam tshuam, ua rau lawv ntau zuj zus daim ntawv thov nyob rau hauv cam khwb cia hlau ntau lawm.
Txoj kev txhim kho rau kev hloov kho kho yog mus rau qis- nqi, siab- ua haujlwm tau zoo, tsis yog - paug, thiab ntau- kev hloov pauv ua haujlwm sib xyaw. Cam khwb cia hlau tau hloov kho kev kho mob siv alloying modifiers uas muaj cov ntsiab lus tsis tshua muaj hauv ntiaj teb, uas ua kom cov nplej zoo dua thaum tseem ua kom huv cov hlau molten. ZL109 alloy, hloov kho nrog kev sib xyaw ntawm Cu-P thiab Al-Ti-B, ua rau zoo- ua kom zoo zoo thawj silicon thiab eutectic silicon hauv nws cov qauv. Sr ntsev tuaj yeem hloov cov theem silicon hauv txhuas-silicon alloys los ntawm rab koob-zoo li tus pas nrig luv-zoo li (nrog qhov ntev hauv qab 100 μm) lossis cov ntaub ntawv nkhaus.
2. Dynamic Crystallization
Dhau li ntawm inoculation thiab hloov kho kev kho rau grain refinement thiab microstructure kev txhim kho, subjecting molten hlau rau ultrasonic vibration kev kho mob los yog electromagnetic stirring kuj ua tau lub hom phiaj ntawm refining nplej thiab txhim kho casting zoo. Kev kho ultrasonic tuaj yeem ua kom zoo dua li - nrum qauv ntawm AS41 magnesium alloy, ua rau MgSi theem finer thiab spheroidized, nrog grain loj tsuas yog 30% mus rau 50% ntawm cov tsis muaj kev kho ultrasonic. Tam sim no, grain refinement thev naus laus zis tab tom hloov mus rau kev sib xyaw ua ke, tsim cov txheej txheem ua ke xws li kev kho inoculation ua ke nrog electromagnetic stirring. Piv txwv li, thaum ntshiab txhuas yog raug rau ib tug ncaj qha tam sim no pulsed magnetic teb ua ke nrog inoculation kev kho mob siv 0.05% Al-5Ti-B, lub resulting grain loj yog txawm finer thiab ntau uniformly faib piv rau kev siv cov tam sim no pulsed magnetic teb ib leeg.
3. Directional Solidification
Directional solidification, tseem hu ua directional crystallization, yog ib txoj kev uas ua rau cov hlau los yog alloys loj hlob muaju nyob rau hauv lub yaj. Cov txheej txheem tseem ceeb rau kev taw qhia kev ruaj ntseg suav nrog txoj kev exothermic pwm, txoj kev txo lub zog, txoj kev ua kom khov sai, thiab cov kua hlau ua kom txias. Directional solidification feem ntau yog siv los npaj columnar nplej thiab ib qho muaju thiab tau ua tiav hauv kev tsim cov nickel-raws li columnar grain thiab ib lub cav siv lead ua. Cov kab lis kev cai ntawm cov kab lis kev cai tshem tawm cov kab hla hla ciam teb, thaum cov pob zeb ib leeg tsis muaj qhov ciam teb ntawm txhua qhov, ua kom muaj qhov siab - qhov kub thiab txias, tsis muaj zog, kev ntxhov siab- cov khoom tawg, thiab thermal qaug zog ua haujlwm ntawm cov hniav.
Ib leeg siv lead ua cov hniav uas tsim los ntawm kev taw qhia solidification yog tsim los ntawm kev xaiv kauv loj hlob los ntawm polycrystals. Seb rau ib leeg siv lead ua loj hlob los yog columnar grain loj hlob lug, lub<100>kev taw qhia yog qhov nyiam kev loj hlob orientation. Los ntawm ntau xyoo ntawm kev tshawb fawb thiab kev loj hlob, kev lag luam tau paub txog cov thev naus laus zis thev naus laus zis rau ib leeg siv lead ua cav hniav, rhuav tshem monopolies. Cov ntaub ntawv ntau thiab kev paub tau raug sau tseg hauv thaj chaw xws li cov thev naus laus zis thev naus laus zis, corundum plhaub pwm tshuab, ib qho siv lead ua kev xaiv thiab cov txheej txheem kev ua kom muaj zog, kev tswj cov khoom siv rov ua dua tshiab rau ib leeg siv lead ua, hluav taws kub tswj, cov txheej txheem nchuav, rub tus nqi, cov txheej txheem kev hloov kho, thiab kev txhim kho pwm. Lub precision casting tshuab rau hollow ib leeg siv lead ua hniav yog ua sophisticated.
