Cov khoom siv ceramic tshwj xeeb yog hais txog ib chav kawm ntawm cov khoom siv ceramic uas muaj cov khoom siv kho tshuab, lub cev lossis tshuaj lom neeg tshwj xeeb, cov khoom siv raw siv thiab cov thev naus laus zis tsim khoom uas xav tau txawv ntawm cov khoom siv ceramic ib txwm muaj thiab kev txhim kho. Raws li cov yam ntxwv thiab kev siv, cov khoom siv ceramic tshwj xeeb tuaj yeem muab faib ua ob pawg: cov khoom siv ceramic thiab cov khoom siv ceramic ua haujlwm. Ntawm lawv, cov khoom siv ceramic yog hais txog cov khoom siv ceramic uas tuaj yeem siv ua cov ntaub ntawv tsim kho, uas feem ntau muaj lub zog siab, siab tawv, siab elastic modulus, kub siab, hnav tsis kam, corrosion tsis kam, oxidation tsis kam, thermal poob siab tsis kam thiab lwm yam ntxwv.
Muaj ntau hom khoom siv ua los ntawm cov khoom siv ceramic, qhov zoo thiab qhov tsis zoo, thiab cov lus qhia ntawm daim ntawv thov ntawm qhov zoo thiab qhov tsis zoo yog txawv, ntawm cov uas "silicon nitride ceramics" vim muaj kev sib npaug ntawm kev ua tau zoo hauv txhua yam, yog lub npe hu ua qhov kev ua tau zoo tshaj plaws hauv tsev neeg cov khoom siv ceramic, thiab muaj ntau yam kev siv.
Cov txiaj ntsig ntawm silicon nitride ceramics
Silicon nitride (Si3N4) muaj peev xwm muab faib ua cov khoom sib txuas covalent, nrog [SiN4] 4-tetrahedron ua lub hauv paus qauv. Cov chaw tshwj xeeb ntawm cov nitrogen thiab silicon atoms tuaj yeem pom los ntawm daim duab hauv qab no, silicon nyob hauv nruab nrab ntawm tetrahedron, thiab cov chaw ntawm plaub lub vertices ntawm tetrahedron yog nyob los ntawm nitrogen atoms, thiab tom qab ntawd txhua peb tetrahedron sib koom ib lub atom, txuas ntxiv mus rau hauv qhov chaw peb-seem. Thaum kawg, cov qauv network tau tsim. Ntau yam ntawm cov khoom ntawm silicon nitride muaj feem cuam tshuam nrog cov qauv tetrahedral no.
Muaj peb hom crystalline ntawm silicon nitride, uas yog α, β thiab γ theem, uas α thiab β theem yog cov qauv feem ntau ntawm silicon nitride. Vim tias cov nitrogen atoms tau sib xyaw ua ke ruaj khov heev, silicon nitride muaj lub zog zoo, siab hardness thiab kub tsis kam, thiab qhov nyuaj tuaj yeem ncav cuag HRA91 ~ 93; Zoo thermal rigidity, tuaj yeem tiv taus qhov kub siab ntawm 1300 ~ 1400 ℃; Kev sib xyaw me me nrog cov pa roj carbon thiab cov hlau ua rau muaj kev sib txhuam coefficient qis; Nws yog tus kheej lubricating thiab yog li ntawd tiv taus hnav; Kev tiv thaiv corrosion yog muaj zog, ntxiv rau hydrofluoric acid, nws tsis cuam tshuam nrog lwm cov inorganic acids, kub siab kuj muaj kev tiv thaiv oxidation; Nws kuj muaj kev tiv thaiv thermal shock zoo, txias sai hauv huab cua thiab tom qab ntawd kub sai yuav tsis tawg; Lub creep ntawm silicon nitride ceramics txo qis ntawm qhov kub siab, thiab qhov qeeb yas deformation yog me me nyob rau hauv qhov kev ua ntawm kub siab thiab ruaj khov load.
Tsis tas li ntawd xwb, silicon nitride ceramics kuj muaj lub zog tshwj xeeb, hom tshwj xeeb siab, thermal conductivity siab, hluav taws xob zoo heev thiab lwm yam zoo, yog li nws muaj txiaj ntsig tshwj xeeb rau daim ntawv thov hauv qhov chaw kub heev xws li kub siab, ceev ceev, muaj zog corrosive media, thiab suav tias yog ib qho ntawm cov khoom siv ceramic zoo tshaj plaws rau kev txhim kho thiab daim ntawv thov, thiab feem ntau dhau los ua thawj qhov kev xaiv hauv ntau daim ntawv thov uas yuav tsum tau sim.
Lub sijhawm tshaj tawm: Lub Yim Hli-15-2023