Solidification ntawm precision castings

Lub solidification ntawm precision castings yog qhov tseem ceeb tshaj rau castings. Feem ntau, cov txheej txheem solidification ntawm castings muab faib ua ob txoj kev: txheej-los-txheej solidification thiab paste solidification raws li cov khoom ntawm cov khoom hlau; Raws li cov qauv ntawm castings, lawv muab faib ua ob txoj kev: sequential solidification thiab simultaneous solidification. Ntawm no kuv xav ceeb toom rau txhua tus neeg tias qhov txheej txheem ntawm txheej txheej thiab muab tshuaj txhuam yog cov khoom ntawm cov ntaub ntawv, uas muaj feem xyuam rau lub sijhawm solidification ntawm cov ntaub ntawv hlau, lossis lub sijhawm crystallization. Lub solidification cheeb tsam yog hais txog lub coexistence cheeb tsam ntawm cov kua-khoom ob theem nyob rau hauv lub molten hlau; lub thiaj li hu ua crystallization cheeb tsam yog qhov kub ntawm qhov sib txawv ntawm cov kua thiab cov solidus ntawm cov hlau molten. Qhov ntsuas kub txiav txim siab li cas cov alloy solidifies. Qhov no yog lub hauv paus ntawm cov khoom. Thaum cov khoom raug xaiv, nws txoj kev solidification kuj raug xaiv thiab txiav txim siab. Tom qab ob txoj kev solidification tsis muaj dab tsi ua rau cov khoom siv hlau, thiab feem ntau txiav txim siab los ntawm cov qauv ntawm cov casting. Txhawm rau kom tau txais ntom ntom, raws li cov qauv ntawm cov casting, nrhiav txoj hauv kev los ntawm cov txheej txheem casting los ua kom pom kev ua pov thawj los txais yuav qee txoj kev signification. Yog li, dab tsi yog txheej txheej los ntawm txheej solidification? Raws li lub npe qhia, nws yog txheej-los-txheej solidification. Uas yog hais, lub sij hawm solidification ntawm cov hlau molten yog ib txoj kab. Lub solidification ntawm ntshiab hlau los yog eutectic alloys crystallized ntawm qhov kub thiab txias ntawm ib qho instant yog txheej-los ntawm-txheej solidification. Simultaneous solidification, raws li lub npe implies, txhais tau hais tias tag nrho cov casting yog solidified nyob rau tib lub sij hawm. Lub solidification cheeb tsam ntawm lub casting yog dav heev, thiab txawm nyob rau hauv ib tug tej lub sij hawm ntawm solidification, lub solidification cheeb tsam khiav los ntawm tag nrho cov seem ntawm lub casting. Yog li, dab tsi yog sequential solidification thiab simultaneous solidification?

1. The so-called sequential solidification is to artificially change the sequence of solidification, so that the castings are solidified according to the process design requirements. Casting first, then gate, and finally riser, so that the shrinkage cavity in the casting is transferred to the riser, and then a dense casting is formed; at the same time, various methods are adopted for solidification to reduce the temperature difference of each part of the casting, so that each part of the casting is in the solidifies at the same time (regardless of its size and structure).

2. Qee tus neeg tuaj yeem nkag siab tias cov khoom siv solidified txheej los ntawm txheej yuav tsum tau txais lub hauv paus ntsiab lus ntawm sequential solidification; thiab cov khoom solidified nyob rau hauv paste daim ntawv yuav tsum tau txais lub hauv paus ntsiab lus ntawm ib txhij solidification. Cov lus no puas yog? Tsis muaj! That' yog qhov peb tham saum toj no. Txheej-los-txheej solidification thiab pasty solidification yog cov khoom ntawm cov khoom hlau nws tus kheej, thiab koj tsis muaj kev xaiv. Yog tias tus neeg siv khoom txiav txim siab cov khoom siv casting, qhov no yog sib npaug rau nws qhov kev txiav txim. Kev sib txuas ua ke thiab kev sib koom ua ke yog txiav txim siab los ntawm koj, tus kws ua haujlwm. Kuv tsis paub' tsis paub yog kuv' kuv hais qhov no kom meej, tab sis kuv xav tias muaj ob peb tus neeg tsis meej pem qhov teeb meem no, yog li nws' tsim nyog rov hais dua ntawm no. Hauv lwm lo lus, cov castings tsim nrog txheej txheej-los ntawm-txheej txheej cov ntaub ntawv tuaj yeem siv lub hauv paus ntsiab lus ntawm ib txhij solidification raws li cov qauv; thaum lub castings tsim nrog mushy solidification cov ntaub ntawv tau txais lub hauv paus ntsiab lus ntawm sequential solidification.

3. Feem ntau, grey hlau, qis carbon steel, muaj tooj liab, txhuas, txhuas-silicon alloy, thiab lwm yam yog tag nrho cov ntaub ntawv uas solidify txheej los ntawm txheej. Cov hlau ductile, siab carbon steel, aluminium-tooj ​​hlau alloy, aluminium-magnesium alloy, magnesium alloy, thiab lwm yam. tag nrho yog cov txheej txheem paste solidification. Muaj lwm qhov teeb meem uas xav tau kev saib xyuas, uas yog, qhov sib txawv ntawm qhov kub thiab txias ntawm ntu casting, los yog qhov kub thiab txias gradient. Thaum qhov kub thiab txias gradient loj, cov khoom zoo li cov khoom sib xyaw ua ke kuj tseem tuaj yeem ua cov txheej txheem los ntawm txheej.