Daim ntawv no qhia txog cov yam ntxwv ntawm silicon nitride ua ke silicon carbide cib. Silicon carbide bricks yog tshwj xeeb refractory cib. Nws tsis tsuas yog muaj cov yam ntxwv ntawm kev ceev ceev, siab zog, zoo thermal shock stability, siab load softening point, zoo thermal conductivity, thiab siab kuj nqi, tab sis kuj muaj zoo heev anti-cryolite zog. , aluminium fluoride, sodium fluoride thiab calcium fluoride thiab lwm yam melting corrosion thiab oxidation kuj. Feem ntau yog siv rau hauv lub tsev huv si ceramics, niaj hnub siv porcelain, hluav taws xob porcelain, txhuas, tooj liab, zinc, steelmaking thiab dov, hlau ua, hlau kho cua sov, kev tiv thaiv ib puag ncig thiab lwm yam.
1 Kev Taw Qhia
Silicon nitride bonded silicon carbide cib yog cov khoom siv tshwj xeeb refractory cib nrog silicon carbide xuab zeb ua cov khoom siv tseem ceeb thiab silicon nitride raws li lub sijhawm khi. Txij li SiC thiab Si3N4 yog ob qho tib si covalent bonds, sintering nyuaj, yog li lawv feem ntau yog npaj los ntawm cov tshuaj tiv thaiv sintering hauv kev tsim khoom. Siv SiC raws li kev sib sau ua ke, ntxiv cov hlau silicon hmoov, xaiv qhov tsim nyog particle gradation, nws cov txheej txheem thiab molding txheej txheem, lub cev ntsuab qhuav raug rho tawm haujlwm hauv cov khoom siv hluav taws xob tshwj xeeb hauv cov cua nitrogen. Thaum lub sij hawm firing txheej txheem, cov generated Si3N4 (matrix binding theem) yog ib tug grey-dawb siv lead ua, uas yuav zoo khi cov SiC hais (tag nrho) ua ke los tsim ib tug spatial network qauv, kom lub cib muaj incomparable yam ntxwv ntawm lwm yam ntaub ntawv refractory. Silicon nitride ua ke nrog cov ntaub ntawv silicon carbide yog txawv teb chaws tsim lub teb chaws xws li Norton thiab Carborundum tuam txhab uas muag nyob rau hauv lub tebchaws United States, An-nawevrk thiab HTK tuam txhab uas muag nyob rau hauv lub teb chaws Yelemees, thiab TKR thiab NGK tuam txhab uas muag nyob rau hauv Nyiv. Silicon carbide tshwj xeeb cib. Cov ntaub ntawv no tau qhia rau hauv kuv lub tebchaws nyob rau nruab nrab -1980s. Tom qab xyoo ntawm kev nce qib thiab daim ntawv thov, cov khoom zoo tshaj ntawm cov khoom tshwj xeeb refractory cilicon nitride ua ke nrog silicon carbide tau maj mam nkag siab.
2. Kev ua tau zoo
Qhov kub-kub flexural zog ntawm silicon nitride ua ke nrog silicon carbide yog 4 mus rau 8 npaug ntawm cov refractories zoo tib yam; thermal expansion coefficient yog ib nrab ntawm cov high-aluminium refractories; Lub thermal conductivity yog 7 mus rau 8 npaug ntawm cov refractories zoo tib yam, thiab lub zog nce nrog kub. Thaum qhov kub nce mus txog 1400 degree, lub zog pib txo qis; tab sis thaum kub poob mus rau 1500 degree, nws tseem tuav lub zog flexural Performance index ntawm chav tsev kub. Lub thermal conductivity ntawm cov khoom maj mam txo nrog qhov nce ntawm qhov kub thiab txias. Nws muaj cov yam ntxwv ntawm qhov zoo thermal shock stability, siab load softening point, zoo thermal conductivity thiab siab kuj nqi, thiab muaj zoo heev kuj rau melting corrosion thiab oxidation kuj ntawm cryolite, aluminium fluoride, sodium fluoride thiab calcium fluoride. Nws qhov kev ua tau zoo tau piav qhia raws li hauv qab no:
1) Silicon nitride ua ke nrog silicon carbide cib yog qhov nyuaj hauv kev ntxhib los mos, nrog Mohs hardness txog li 9. Lawv yog cov ntaub ntawv hardness siab ntawm cov ntaub ntawv uas tsis yog xim hlau, thiab lawv cov hardness yog thib ob tsuas yog pob zeb diamond.
2) Qhov kub thiab txias lub zog ntawm silicon nitride ua ke silicon carbide cib yog qhov siab, thiab nws yuav luag tuav tib lub zog thiab hardness li qhov qub kub ntawm qhov kub ntawm 1200-1400 degree. Nrog rau kev siv cov huab cua sib txawv, qhov siab tshaj plaws siv qhov kub thiab txias tuaj yeem ncav cuag 1650 ~ 1750 degree.
3) Lub thermal expansion coefficient yog me me, thermal conductivity yog siab piv rau silicon carbide thiab lwm yam cib, nws tsis yooj yim los tsim thermal stress, muaj thermal shock stability, thiab muaj kev pab lub neej ntev. Kub creep kuj, corrosion kuj, huab cua txias thiab kub tsis kam, oxidation kuj, yooj yim rau ua rau tshwj xeeb refractory bricks nrog siab qhov tseeb thiab yuav tsum tau.
Hauv tsab xov xwm tom ntej no, peb yuav tham txog kev siv ntau yam ntawm silicon nitride ua ke nrog silicon carbide cib.
