Hauvpeev castingtxheej txheem, qhov zoo ntawm lub plhaub pwm ncaj qha txiav txim siab qhov tseeb, qhov zoo ntawm qhov chaw, thiab cov khoom siv tshuab ntawm cov casting. Cov yam ntxwv ntawm cov khoom siv raw yog lub hauv paus tseem ceeb rau kev ua haujlwm ntawm lub plhaub pwm. Plhaub- ua cov ntaub ntawv raw feem ntau suav nrog cov ntaub ntawv refractory thiab lub kaw lus binder, ob qho tib si yuav tsum muaj cov yam ntxwv tshwj xeeb kom ua tau raws li cov kev xav tau nruj ntawm lub plhaub- ua, tua hluav taws, thiab cov txheej txheem casting.
I. Cov Khoom Siv Hluav Taws Xob: Cov Tub Ntxhais Ua Haujlwm ntawm Siab - Kev Ua Haujlwm Kub Kub ntawm Pwm Plhaub
Cov ntaub ntawv refractory tsim cov pob txha ntawm lub plhaub pwm thiab yuav tsum muaj qhov zoo tshaj plaws - qhov kub thiab txias, haum qhov loj me me tis, thiab zoo tshuaj inertness. Feem ntau siv cov hmoov refractory muaj xws li silica, zirconium oxide, thiab alumina. Lawv cov purity ncaj qha cuam tshuam rau kev ua haujlwm ntawm lub plhaub pwm- siab purity tiv thaiv impurities los ntawm kev ua kom kub tawg ntawm qhov kub thiab txias los yog ua rau cov tshuaj lom neeg nrog cov hlau molten los ua cov khoom tsis zoo, ua rau kev ua tsis tiav. Piv txwv li, thaum casting siab -kub alloys, yog hais tias cov khoom refractory muaj tsawg-melting- taw tes impurities, nws yooj yim softens thiab melts ntawm qhov kub thiab txias, kis tus nto casting.
Particle loj faib yuav tsum sib npaug saum npoo tiav nrog permeability thiab lub zog. Cov khoom me me tuaj yeem ua tiav qhov khoob hauv lub plhaub pwm, txhim kho qhov ua tiav ntawm qhov casting, tab sis lawv txo lub plhaub permeability, tiv thaiv cov roj tsim tawm thaum tua hluav taws thiab nchuav los ntawm kev khiav tawm kom zoo thiab tsim cov porosity tsis xws luag. Coarser particles nce lub plhaub porosity, txhim kho permeability thiab sintering zog, tab sis lawv txo lub plhaub lub peev xwm los replicate cov ntsiab lus los ntawm cov peev pwm, cuam tshuam rau cov casting qhov seem raug. Hauv kev tsim khoom tiag tiag, ntau -theem particle loj faib feem ntau yog siv los ua kom zoo dua.
II. Binder System: Ib qho kev txhawb nqa tseem ceeb rau lub plhaub tsim thiab lub zog
Lub binder yog lub luag haujlwm rau kev sib txuas cov khoom refractory rau hauv cov duab. Nws qhov zoo txiav txim siab lub plhaub qhov adhesion, ziab ceev, sintering yam ntxwv, thiab chav tsev / kub lub zog. Feem ntau siv cov binders muaj xws li silica sol thiab ethyl silicate, uas yuav tsum muaj viscosity ruaj khov thiab kho cov khoom- tsis sib haum viscosity ua rau cov thickness tsis sib npaug ntawm cov slurry refractory thaum thov, thiab tsis ruaj khov kho cov khoom yooj yim ua rau lub plhaub delamination, tawg, los yog tsis txaus cov khoom sib txuas thaum lub sij hawm deformation, uas ua rau lub plhaub tsis sib xws.
Tsis tas li ntawd, cov nplaum yuav tsum muaj cov khoom zoo siab -kub decomposition, ua kom nws hlawv tag nrho los yog decompose thaum lub sij hawm calcination yam tsis muaj qhov seem seem impurities kom tsis txhob kis tus kab mob. Nyob rau tib lub sijhawm, nws yuav tsum muaj kev sib raug zoo nrog cov khoom siv refractory los xyuas kom meej ib daim ntawv cog lus nruj thiab tsim lub plhaub ruaj khov. Piv txwv li, qhov loj me me thiab cov concentration ntawm silica sol adhesives yuav tsum tau tswj kom lav cov txheej txheem kev ua tau zoo thiab kev sib txuas lub zog, ua tau raws li qhov yuav tsum tau ua ntawm cov txheej txheem tom ntej.
