Castability (casting cuab yeej) ntawm alloy yog hais txog cov cuab yeej technology ntawm cov hlau thaum lub sij hawm casting, feem ntau suav nrog cov fluidity thiab shrinkage ntawm cov hlau. Cov khoom no tseem ceeb heev kom tau txais cov suab nrov nrov.
kev txav mus los
Liquidity yog hais txog lub peev xwm ntawm cov kua alloy los sau cov pwm.
Lub fluidity ntawm cov kua alloy yog zoo, thiab nws yog ib qho yooj yim mus sau cov pwm kab noj hniav kom tau txais castings nrog meej contour thiab tiav loj. Ntawm qhov tsis sib xws, yog tias qhov fluidity ntawm cov hlau tsis zoo, cov teeb meem xws li tsis txaus pouring, txias kaw, porosity thiab slag suav nrog yog ib qho yooj yim tshwm sim.
Ntawm cov feem ntau siv alloys, grey cam khwb cia hlau thiab silicon tooj dag muaj qhov zoo tshaj plaws fluidity, thaum cam khwb cia hlau muaj qhov phem tshaj fluidity.
Muaj ntau yam uas cuam tshuam rau lub fluidity, nrog rau cov tshuaj muaj pes tsawg leeg ntawm cov alloy, pouring kub thiab filling tej yam kev mob ntawm pwm.
Kev cog lus
Qhov tshwm sim uas qhov ntim thiab qhov loj ntawm cov kua alloy txo qis tsis tu ncua thaum lub caij txias thiab solidification yog hu ua contraction. Shrinkage yog lub cev khoom ntawm casting alloy nws tus kheej thiab lub hauv paus ua rau ntau yam tsis xws luag (shrinkage kab noj hniav, porosity, sab hauv kev nyuaj siab, deformation thiab tawg, thiab lwm yam) nyob rau hauv castings. Qhov txias ntawm cov kua alloy los ntawm pouring rau hauv pwm kab noj hniav mus rau chav tsev kub mus txog peb theem:
1. Kua contraction: lub contraction ntawm txias ntawm pouring kub thiab liquidus kub ntawm crystallization pib.
2. Solidification contraction: qhov contraction los ntawm qhov pib crystallization kub mus rau solidus kub tom qab crystallization.
3. Cov ntawv cog lus ruaj khov: qhov kev cog lus los ntawm qhov kub thiab txias tom qab crystallization mus rau chav sov.
Cov kua shrinkage thiab solidification shrinkage ntawm cov hlau yog qhia raws li lub ntim shrinkage ntawm lub alloy, uas feem ntau yog qhia los ntawm lub ntim shrinkage tus nqi. Lawv yog cov laj thawj tseem ceeb rau lub shrinkage kab noj hniav thiab porosity defects ntawm lub casting. Txawm hais tias cov khoom shrinkage ntawm cov hlau kuj yog ib qho kev hloov pauv, nws tsuas yog ua rau kev hloov pauv ntawm qhov ntev ntawm qhov casting. Yog li ntawd, nws yog feem ntau qhia los ntawm linear shrinkage. Khoom shrinkage yog cov hauv paus ntsiab lus ntawm kev ua tsis xws luag xws li kev ntxhov siab sab hauv, deformation thiab tawg.
Cov tshuaj muaj pes tsawg leeg, pouring kub, pwm mob thiab casting qauv ntawm lub alloy yog lub ntsiab yam tseem ceeb cuam tshuam lub shrinkage ntawm lub alloy. Qhov tseeb shrinkage txawv nrog cov duab, qhov loj thiab cov txheej txheem ntawm castings.
Tsis tas li ntawd, qhov tshwm sim uas cov tshuaj muaj pes tsawg leeg ntawm txhua feem ntawm cov kua alloy tsis zoo ib yam nyob rau hauv cov txheej txheem ntawm txias mus rau hauv lub casting, namely, cais, gas nqus thiab oxidation, muaj kev cuam tshuam tsis zoo rau lub casting kev ua tau zoo.
