Cov khoom siv silicon carbide ceramics muaj lub zog kub siab, tiv taus oxidation kub siab, tiv taus hnav zoo, ruaj khov thermal zoo, coefficient me me ntawm thermal nthuav dav, thermal conductivity siab, hardness siab, tiv taus kub poob siab, tiv taus tshuaj corrosion thiab lwm yam zoo heev. Nws tau siv dav hauv tsheb, tshuab, kev tiv thaiv ib puag ncig, aerospace technology, cov ntaub ntawv hluav taws xob, lub zog thiab lwm yam teb, thiab tau dhau los ua cov khoom siv ceramic uas tsis muaj qhov hloov pauv nrog kev ua tau zoo heev hauv ntau qhov chaw lag luam. Tam sim no cia kuv qhia koj!
Kev sintering tsis muaj siab
Kev sintering tsis muaj siab yog suav hais tias yog txoj kev cog lus tshaj plaws rau SiC sintering. Raws li cov txheej txheem sintering sib txawv, kev sintering tsis muaj siab tuaj yeem faib ua cov khoom khov kho thiab cov kua theem sintering. Los ntawm ultra-fine β-A tus nqi tsim nyog ntawm B thiab C (cov ntsiab lus oxygen tsawg dua 2%) tau ntxiv rau SiC hmoov tib lub sijhawm, thiab s. proehazka tau sintered rau SiC sintered lub cev nrog qhov ceev siab dua 98% ntawm 2020 ℃. A. Mulla et al. Al2O3 thiab Y2O3 tau siv ua cov khoom ntxiv thiab sintered ntawm 1850-1950 ℃ rau 0.5 μ m β-SiC (qhov chaw ntawm cov khoom me me muaj SiO2 me me). Qhov ceev sib piv ntawm SiC ceramics tau txais yog ntau dua 95% ntawm qhov ceev theoretical, thiab qhov loj me ntawm cov noob me me thiab qhov nruab nrab. Nws yog 1.5 microns.
Kub nias sintering
SiC ntshiab tsuas yog tuaj yeem sintered compactly ntawm qhov kub siab heev yam tsis muaj cov khoom ntxiv sintering, yog li ntau tus neeg siv cov txheej txheem kub nias sintering rau SiC. Muaj ntau daim ntawv tshaj tawm txog kev kub nias sintering ntawm SiC los ntawm kev ntxiv cov khoom pab sintering. Alliegro et al. Kawm txog cov nyhuv ntawm boron, txhuas, nickel, hlau, chromium thiab lwm yam khoom ntxiv hlau rau SiC densification. Cov txiaj ntsig qhia tau tias txhuas thiab hlau yog cov khoom ntxiv zoo tshaj plaws los txhawb SiC kub nias sintering. FFlange kawm txog cov nyhuv ntawm kev ntxiv ntau yam ntawm Al2O3 rau cov khoom ntawm kub nias SiC. Nws tau txiav txim siab tias qhov densification ntawm kub nias SiC yog cuam tshuam nrog cov txheej txheem ntawm kev yaj thiab nag lossis daus. Txawm li cas los xij, cov txheej txheem kub nias sintering tsuas yog tuaj yeem tsim cov khoom SiC nrog cov duab yooj yim. Cov khoom tsim los ntawm ib zaug kub nias sintering txheej txheem yog me me heev, uas tsis zoo rau kev tsim khoom lag luam.
Kub isostatic nias sintering
Yuav kom kov yeej qhov tsis zoo ntawm cov txheej txheem sintering ib txwm muaj, B-hom thiab C-hom tau siv ua cov khoom ntxiv thiab cov thev naus laus zis kub isostatic nias sintering tau saws. Ntawm 1900 ° C, cov khoom siv crystalline zoo nrog qhov ceev ntau dua 98 tau txais, thiab lub zog khoov ntawm chav tsev kub tuaj yeem ncav cuag 600 MPa. Txawm hais tias kub isostatic nias sintering tuaj yeem tsim cov khoom ntom ntom nrog cov duab nyuaj thiab cov khoom siv kho tshuab zoo, qhov sintering yuav tsum tau kaw, uas nyuaj rau ua tiav kev tsim khoom lag luam.
Kev sib xyaw ua ke ntawm cov tshuaj tiv thaiv
Cov tshuaj tiv thaiv sintered silicon carbide, tseem hu ua tus kheej bonded silicon carbide, yog hais txog cov txheej txheem uas porous billet reacts nrog roj lossis kua theem los txhim kho billet zoo, txo porosity, thiab sintered cov khoom tiav nrog qee lub zog thiab qhov tseeb. coj α- SiC hmoov thiab graphite sib xyaw ua ke hauv qee qhov sib piv thiab cua sov rau txog 1650 ℃ los ua ib lub billet square. Tib lub sijhawm, nws nkag mus lossis nkag mus rau hauv billet los ntawm gaseous Si thiab reacts nrog graphite los tsim β- SiC, ua ke nrog α- SiC cov khoom uas twb muaj lawm. Thaum Si raug infiltrated tag nrho, lub cev sintered tshuaj tiv thaiv nrog qhov ceev tag nrho thiab tsis shrinkage loj tuaj yeem tau txais. Piv nrog rau lwm cov txheej txheem sintering, qhov kev hloov pauv loj ntawm cov tshuaj tiv thaiv sintering hauv cov txheej txheem densification yog me me, thiab cov khoom nrog qhov loj me raug tuaj yeem npaj tau. Txawm li cas los xij, qhov muaj ntau ntawm SiC hauv lub cev sintered ua rau cov khoom kub siab ntawm cov tshuaj tiv thaiv sintered SiC ceramics phem dua.
Lub sijhawm tshaj tawm: Lub Rau Hli-08-2022