Silicon carbide (SiC) ceramic hmoovmuaj qhov zoo ntawm qhov kub thiab txias zog, zoo oxidation tsis kam, siab hnav tsis kam thiab thermal stability, me me thermal expansion coefficient, siab thermal conductivity, zoo tshuaj stability, thiab lwm yam. Yog li ntawd, nws yog feem ntau siv nyob rau hauv lub tsim ntawm combustion chamber, kub tso pa tawm. cov khoom siv, qhov kub thiab txias tiv thaiv thaj chaw, cov khoom siv dav hlau dav hlau, cov tshuaj tiv thaiv cov hlab ntsha, cov hlab cua sov thiab lwm yam khoom siv hauv cov khoom hnyav, thiab yog cov khoom siv dav siv hauv kev tsim kho.Nws tsis tsuas yog ua lub luag haujlwm tseem ceeb hauv kev ua haujlwm siab hauv kev tsim kho (xws li lub cav ceramics, dav hlau, thiab lwm yam), tab sis kuj tseem muaj kev lag luam dav thiab daim ntawv thov kev lag luam uas yuav tsum tau tsim nyob rau hauv lub zog tam sim no, metallurgy, machinery, khoom siv hauv tsev. , chemical kev lag luam thiab lwm yam kev lag luam.

Txoj kev npaj ntawmsilicon carbide hmoovtuaj yeem muab faib ua peb pawg: cov txheej txheem txheej txheem, cov txheej txheem ua kua theem thiab cov txheej txheem roj.

1. Khoom theem txheej txheem

Cov txheej txheem txheej txheem feem ntau suav nrog txoj kev txo qis carbothermal thiab silicon carbon direct tshuaj tiv thaiv txoj kev.Txoj kev txo cov pa roj carbon monoxide kuj muaj xws li Acheson txoj kev, txoj hauv kev ntsug rauv thiab txoj kev hloov pauv kub kub.Silicon carbide hmoovKev npaj tau pib npaj los ntawm Acheson txoj kev, siv coke los txo cov silicon dioxide ntawm qhov kub thiab txias (txog 2400 ℃), tab sis cov hmoov tau los ntawm txoj kev no muaj qhov loj me me (> 1 hli), siv ntau lub zog, thiab cov txheej txheem yog nyuaj.Nyob rau xyoo 1980s, cov khoom siv tshiab rau kev sib xyaw β-SiC hmoov, xws li ntsug rauv thiab lub siab kub hloov pauv, tau tshwm sim.Raws li qhov ua tau zoo thiab tshwj xeeb polymerization ntawm microwave thiab tshuaj lom neeg hauv cov khoom tau maj mam qhia meej, thev naus laus zis ntawm kev sib xyaw sic hmoov los ntawm microwave cua sov tau dhau los ua neeg paub tab.Cov txheej txheem silicon carbon ncaj qha cov tshuaj tiv thaiv kuj muaj xws li nws tus kheej-propagating kub synthesis (SHS) thiab mechanical alloying txoj kev.SHS txo cov synthesis txoj kev siv cov tshuaj tiv thaiv exothermic ntawm SiO2 thiab Mg los ua kom tsis muaj cua sov.Covsilicon carbide hmoovtau los ntawm txoj kev no muaj siab purity thiab me me particle loj, tab sis Mg nyob rau hauv cov khoom yuav tsum tau muab tshem tawm los ntawm cov txheej txheem tom ntej xws li pickling.

2 kua theem txoj kev

Txoj kev ua kua theem feem ntau suav nrog sol-gel txoj kev thiab polymer thermal decomposition txoj kev.Txoj kev Sol-gel yog ib txoj hauv kev npaj cov gel uas muaj Si thiab C los ntawm cov txheej txheem sol-gel, thiab tom qab ntawd pyrolysis thiab kub kub txo kom tau txais silicon carbide.Kev kub siab decomposition ntawm cov organic polymer yog ib qho cuab yeej zoo rau kev npaj ntawm silicon carbide: ib qho yog kom sov gel polysiloxane, decomposition cov tshuaj tiv thaiv kom tso cov monomers me me, thiab thaum kawg tsim SiO2 thiab C, thiab tom qab ntawd los ntawm carbon txo cov tshuaj tiv thaiv los tsim SiC hmoov;Lwm qhov yog ua kom sov polysilane lossis polycarbosilane tso tawm cov monomers me me los ua ib lub cev pob txha, thiab thaum kawg daim ntawvsilicon carbide hmoov.

3 Gas theem txoj kev

Tam sim no, cov roj theem synthesis ntawmsilicon carbideceramic ultrafine hmoov mas siv roj theem deposition (CVD), Plasma Induced CVD, Laser Induced CVD thiab lwm yam technologies los decompose organic teeb meem ntawm kub.Cov hmoov tau txais qhov zoo ntawm siab purity, me me particle loj, tsawg particle agglomeration thiab yooj yim tswj ntawm cov khoom.Nws yog ib txoj hauv kev zoo heev tam sim no, tab sis nrog tus nqi siab thiab tsis tshua muaj txiaj ntsig, nws tsis yooj yim rau kev ua tiav ntau lawm, thiab tsim nyog rau kev ua cov khoom siv kuaj thiab cov khoom siv tshwj xeeb.

Tam sim no, lubsilicon carbide hmoovsiv tsuas yog submicron los yog txawm nano qib hmoov, vim hais tias cov hmoov particle loj me me, siab nto kev ua si, yog li qhov teeb meem tseem ceeb yog cov hmoov yooj yim los tsim agglomeration, nws yog ib qho tsim nyog yuav tsum tau hloov kho qhov saum npoo ntawm cov hmoov los tiv thaiv lossis inhibit. theem nrab agglomeration ntawm cov hmoov.Tam sim no, cov txheej txheem ntawm dispersion ntawm SiC hmoov feem ntau suav nrog cov pawg hauv qab no: kev hloov kho lub zog siab, kev ntxuav, kev kho cov hmoov dispersant, inorganic txheej hloov kho, hloov kho cov txheej txheem organic.