Sintering aid yog ib hom khoom siv uas tuaj yeem txhawb nqa cov ntaub ntawv kom sintered kom ze rau qhov theoretical ntom ntom ntawm qhov kub qis dua li qhov melting point ntawm cov khoom nws tus kheej. Txawm li cas los xij, cov txheej txheem ntawm cov khoom siv no los txhawb sintering yog qhov nyuaj heev. Lub sintering mechanism ntawm tib cov ntaub ntawv uas sib txawv sintering pab tej zaum yuav txawv. Lub mechanism ntawm sintering pab los txhawb sintering yog raws li nram no:
(1) Nws tsim cov kev daws teeb meem nrog sinter. Thaum cov kev daws teeb meem tsim los ntawm kev pab sintering thiab sintering, cov khoom siv lead ua yuav raug distorted thiab qhib, uas tuaj yeem txo qhov kub ntawm sintering thiab ua rau kom qhov sib txawv thiab sintering ceev, uas yog ib qho tseem ceeb tshwj xeeb tshaj yog rau kev tsim cov khoom seem lossis interstitial yam khoom. kev daws teeb meem. Yog tias Cr2O3 ntxiv rau lub sijhawm Al2O3 sintering, cov kev daws teeb meem txuas ntxiv tuaj yeem tsim tau vim qhov ze ze zoo ion radius ntawm Al2O3 thiab Cr2O3. Thaum TiO2 ntxiv, sintering kub qis dua. Vim hais tias qhov loj ntawm Ti4 ntxiv ions yog tib yam li ntawm Cr3 ntxiv ions, ntxiv rau cov khoom soluble nrog Al2O3, thiab vim tias cov nqi hluav taws xob ntawm Ti4 ntxiv thiab Al3 ntxiv yog qhov sib txawv, qhov zoo ion vacancy yuav tshwm sim tom qab hloov, uas tuaj yeem ua tau. zoo txhawb sintering.
(2) Tiv thaiv crystal transformation. Qee cov oxides yuav raug hloov pauv siv lead ua nrog lub ntim loj thaum lub sij hawm sintering, uas yuav ua rau sintering densification nyuaj thiab yooj yim ua rau ntsuab lub cev tawg. Xaiv cov khoom siv sintering uas tsim nyog tuaj yeem cuam tshuam cov nyhuv ntim thiab txhawb nqa sintering, xws li ntxiv ib qho nyiaj ntawm CaO rau ZrO2 sintering qhib. Thaum txog 1200 degree, qhov ruaj khov monoclinic ZrO2 hloov mus rau hauv square ZrO2, uas yuav tau nrog 10 feem pua ntim shrinkage, yog li deteriorating stability ntawm cov khoom. Yog tias Ca2 ntxiv rau ions nrog tus nqi hluav taws xob qis dua ZrO4 ntxiv tau qhia, cubic Zr1-xCaxO2 ruaj khov kho tuaj yeem tsim. Qhov no tsis tsuas yog tiv thaiv cov khoom los ntawm kev tawg, tab sis kuj ua rau kom qhov chaw nyob hauv cov khoom siv lead ua, uas ua rau lub sintering.
(3) inhibit qhov txawv txav ntawm granules. Feem ntau, cov nplej loj hlob zoo rau sintering tom qab theem ntawm sintering. Txawm li cas los xij, yog hais tias theem nrab recrystallization los yog sib sib zog nqus grain loj hlob sai heev, rov qab densification yuav tshwm sim vim grain coarsening thiab ciam widening. Lub sijhawm no, cov txheej txheem densification tuaj yeem txhawb nqa los ntawm kev ntxiv cov khoom siv sintering uas tuaj yeem cuam tshuam cov qoob loo loj hlob. Piv txwv li, ntxiv MgO rau hauv Al2O3 yog ib qho piv txwv zoo. Txawm li cas los xij, nws yuav tsum tau taw qhia tias kev loj hlob ntawm cov qoob loo ib txwm muaj txiaj ntsig zoo, thiab kev loj hlob tsis txawv txav yuav tsum tau muab tshem tawm thiab tswj.
(4) Ua kom haum cov kua theem. Yog tias muaj cov kua dej tsim nyog thaum lub sij hawm sintering, nws yuav zoo heev txhawb cov particle rearrangement thiab loj hloov cov txheej txheem, los yog cov kua-cov tshuaj tiv thaiv yuav tsim ib tug tshiab cement theem ntawm ib tug qis kub los txhawb sintering. Cov tsos ntawm cov kua theem yuav yog vim qhov qis melting point ntawm sintering pab nws tus kheej, los yog nws yuav tsim ib tug tsawg eutectic nrog lub sinter. Ntxiv boric acid los yog boric anhydride rau cov khoom vibrating qhuav yog hom zoo li no.
Cov khoom raug rho tawm haujlwm ntawm refractory cib tsim los ntawm Kerui Refractory muaj xws li av nplaum cib, siab alumina cib, lub teeb insulating cib, silica cib, magnesia cib, carbon cib, thiab cov khoom sib xyaw refractory, carbonated oxide refractory khoom, thiab lwm yam.
