Parizvino,kabhidhi yesilicon (SiC)chinhu checeramic chinofambisa kupisa chinodzidzwa zvakanyanya kumba nekune dzimwe nyika. Kufambisa kweSiC kwedzidziso yekupisa kwakanyanya, uye mamwe marudzi ekristaro anogona kusvika 270W/mK, iyo yatove mutungamiriri pakati pezvinhu zvisiri zvinofambisa kupisa. Semuenzaniso, kushandiswa kweSiC thermal conductivity kunogona kuonekwa muzvinhu zve substrate zvemidziyo ye semiconductor, zvinhu zveceramic zvinofambisa kupisa zvakanyanya, maheater nema heating plates ekugadzirisa semiconductor, zvinhu zve capsule zve nuclear fuel, uye gas sealing rings dze compressor pumps.
Kushandiswa kwekabhidhi yesiliconmumunda we semiconductor
Madhisiki ekukuya nemidziyo yemagetsi zvinhu zvakakosha pakugadzira silicon wafer muindasitiri yesemiconductor. Kana dhisiki yekukuya yakagadzirwa nesimbi yakakandwa kana simbi yekabhoni, hupenyu hwayo hwekushanda hupfupi uye thermal expansion coefficient yayo yakakura. Munguva yekugadzirisa silicon wafers, kunyanya panguva yekukuya nekukurumidza kana kupukuta, nekuda kwekusakara uye thermal deformation yedhisiki yekukuya, kutsetseka uye kufanana kwesilicon wafer zvakaoma kuvimbisa. Dhisiki yekukuya yakagadzirwa nezviumbwa zvesimbi zvesilicon carbideHaina kupfeka zvakanyanya nekuda kwekuoma kwayo kwakanyanya, uye thermal expansion coefficient yayo yakafanana neye silicon wafers, saka inogona kukuyiwa nekukweshwa nekumhanya kwakanyanya.
Pamusoro pezvo, kana mawafer esilicon agadzirwa, anofanirwa kupiswa zvakanyanya uye anowanzo fambiswa achishandisa silicon carbide fixtures. Haapisi uye haaparadzi. Carbon yakaita sedhaimani (DLC) nezvimwe zvinogona kuiswa pamusoro kuti zviwedzere kushanda, kuderedza kukuvara kwewafer, uye kudzivirira kusvibiswa kuti kusapararire.
Uyezve, semumiriri wezvinhu zve semiconductor zvechizvarwa chechitatu zve wide-bandgap, zvinhu zve silicon carbide single crystal zvine hunhu hwakadai se bandgap width yakakura (inenge katatu kupfuura Si), high thermal conductivity (inenge katatu kupfuura Si kana kagumi kupfuura GaAs), high electron saturation migration rate (inenge kaviri nehafu kupfuura Si) uye high breakdown electric field (inenge gumi kupfuura Si kana kashanu kupfuura GaAs). SiC devices dzinogadzirisa zvikanganiso zvemidziyo ye semiconductor yechinyakare mumashandisirwo anoshanda uye zvishoma nezvishoma dziri kuva mainstream ye power semiconductors.
Kudiwa kwesimbi dzesilicon carbide ceramics dzinoshandisa mafuta akawanda kwakawedzera zvakanyanya.
Nekufambira mberi kwesainzi netekinoroji, kudiwa kwekushandiswa kwesilicon carbide ceramics mumunda we semiconductor kwakawedzera zvakanyanya, uye high thermal conductivity chiratidzo chikuru chekushandiswa kwayo muzvikamu zvemichina yekugadzira semiconductor. Nokudaro, zvakakosha kusimbisa tsvakurudzo pamusoro pe high thermal conductivity silicon carbide ceramics. Kuderedza huwandu hwe lattice oxygen, kuvandudza density, uye kudzora zvine musoro kupararira kwechikamu chechipiri mu lattice ndiyo nzira huru dzekuvandudza thermal conductivity ye silicon carbide ceramics.
Parizvino, kune zvidzidzo zvishoma pamusoro pezvinhu zvesimbi zvesilicon carbide zvinoshandisa thermal conductivity munyika yangu, uye kuchine musiyano mukuru kana tichienzanisa nepasi rose. Nzira dzekutsvaga mune ramangwana dzinosanganisira:
●Simbisa maitiro ekugadzirira tsvakurudzo yeupfu hwe silicon carbide ceramic. Kugadzira upfu hwe silicon carbide hwakachena zvakanyanya, hune oxygen shoma ndiyo hwaro hwekugadzirira upfu hwe silicon carbide ceramics hunopfuta zvakanyanya;
● Simbisa kusarudzwa kwezvinobatsira pakurapa nekushandisa sintering uye tsvakurudzo dzedzidziso dzakabatana nadzo;
●Simbisa tsvakurudzo nekugadzirwa kwemidziyo yepamusoro-soro yekusvina. Nekugadzirisa maitiro ekusvina kuti uwane chimiro chakanaka, chinhu chinodiwa kuti uwane ceramics dzesilicon carbide dzinopisa zvakanyanya.
Matanho ekuvandudza kupisa kwesimbi dzesilicon carbide
Chinhu chikuru chekuvandudza kufambiswa kwekupisa kweSiC ceramics ndechekuderedza kupararira kwemaphonon uye kuwedzera nzira yakasununguka yephonon. Kufambiswa kwekupisa kweSiC kuchavandudzwa zvinobudirira nekuderedza porosity uye huwandu hwezviyo zveSiC ceramics, kuvandudza kuchena kwemiganhu yezviyo zveSiC, kuderedza kusvibiswa kweSiC lattice kana kukanganisa kwelattice, uye kuwedzera chinotakura kupisa muSiC. Parizvino, kugadzirisa mhando uye zviri mukati mezvinobatsira pakupisa uye kurapwa kwekupisa kwakanyanya ndiwo matanho makuru ekuvandudza kufambiswa kwekupisa kweSiC ceramics.
① Kugadzirisa mhando uye zviri mukati mezvinobatsira pakuchenesa
Zvishandiso zvakasiyana-siyana zvekuisa sintering zvinowanzowedzerwa pakugadzira SiC ceramics dzinofambisa kupisa zvakanyanya. Pakati padzo, mhando uye zviri mukati mezvishandiso zvekuisa sintering zvine simba guru pakufambisa kupisa kweSiC ceramics. Semuenzaniso, zvinhu zveAl kana O muAl2O3 system zvinoisa sintering zvinonyungudika nyore nyore muSiC lattice, zvichikonzera nzvimbo dzisina chinhu uye zvikanganiso, izvo zvinotungamira mukuwedzera kwehuwandu hwekupararira kwephonon. Pamusoro pezvo, kana zviri mukati mezvishandiso zvekuisa sintering zvakaderera, zvinhu zvakaoma kuisa sintering uye density, nepo huwandu hwakawanda hwezvishandiso zvekuisa sintering huchizotungamira mukuwedzera kwekusvibiswa uye zvikanganiso. Zvishandiso zvekuisa sintering zvakanyanya zvinogonawo kudzivirira kukura kweSiC grains uye kuderedza nzira yakasununguka yemaphonon. Saka, kuti ugadzirire SiC ceramics dzinofambisa kupisa zvakanyanya, zvakakosha kuderedza zviri mukati mezvishandiso zvekuisa sintering zvakanyanya sezvinobvira uchisangana nezvinodiwa zvekuisa sintering density, uye edza kusarudza zvishandiso zvekuisa sintering zvakaoma kunyungudika muSiC lattice.
*Hunhu hwekupisa hweSiC ceramics kana zvinhu zvakasiyana-siyana zvinoshandisa sintering zvawedzerwa
Parizvino, SiC ceramics dzakapiswa nekupisa dzakapiswa neBeO semubatsiri wekusvina dzine simba guru rekupisa kwekamuri (270W·m-1·K-1). Zvisinei, BeO chinhu chine chepfu yakawanda uye chinokonzera kenza, uye hachina kukodzera kushandiswa zvakanyanya mumarabhoritari kana minda yemaindasitiri. Nzvimbo yakaderera ye eutectic system yeY2O3-Al2O3 i1760℃, inova ndiyo liquid-phase sintering aid yeSiC ceramics. Zvisinei, sezvo Al3+ ichinyungudutswa nyore nyore muSiC lattice, kana iyi system ichishandiswa semubatsiri wekusvina, SiC ceramics isingasviki 200W·m-1·K-1.
Zvinhu zvisingawanzoitiki zvepanyika zvakaita seY, Sm, Sc, Gd naLa hazvinyunguduke nyore muSiC lattice uye zvine oxygen yakawanda, izvo zvinogona kuderedza zviri nani oxygen muSiC lattice. Saka, Y2O3-RE2O3 (RE=Sm, Sc, Gd, La) system inzira yakajairika yekubatsira kugadzira high thermal conductivity (>200W·m-1·K-1) SiC ceramics. Tichitora Y2O3-Sc2O3 system sintering aid semuenzaniso, ion deviation value yeY3+ neSi4+ yakakura, uye zviviri izvi hazvipindi mu solid solution. Kunyunguduka kweSc mu pure SiC pa 1800~2600℃ kudiki, inenge (2~3)×1017atoms·cm-3.
② Kurapa kupisa kwakanyanya
Kurapa kupisa kwakanyanya kweSiC ceramics kunobatsira kubvisa zvikanganiso zve lattice, dislocations uye residual stress, zvichikurudzira kushanduka kwechimiro chezvimwe zvinhu zvisina chimiro kuita makristaro, uye kuderedza simba re phonon scattering effect. Pamusoro pezvo, kurapwa kupisa kwakanyanya kunogona kukurudzira kukura kweSiC grains, uye pakupedzisira kunatsiridza hunhu hwekupisa hwezvinhu. Semuenzaniso, mushure mekupisa kwakanyanya pa1950°C, thermal diffusion coefficient yeSiC ceramics yakawedzera kubva pa83.03mm2·s-1 kusvika 89.50mm2·s-1, uye thermal conductivity yekamuri-tembiricha yakawedzera kubva pa180.94W·m-1·K-1 kusvika 192.17W·m-1·K-1. Kurapa kupisa kwakanyanya kunovandudza kugona kwe deoxidation kwerubatsiro rwe sintering pamusoro peSiC ne lattice, uye kunoita kuti kubatana pakati peSiC grains kuve kwakasimba. Mushure mekupisa kwakanyanya, thermal conductivity yekamuri-tembiricha yeSiC ceramics yakagadziridzwa zvakanyanya.
Nguva yekutumira: Gumiguru-24-2024