Okwamanje,i-silicon carbide (i-SiC)kuyinto esetshenziswayo yobumba eqhuba ukushisa efundwa ngenkuthalo ekhaya nakwamanye amazwe. Ukuguquguquka kokushisa kwe-SiC okungokwemfundiso kuphezulu kakhulu, futhi ezinye izinhlobo zekristalu zingafinyelela ku-270W/mK, okuvele kungumholi phakathi kwezinto ezingezona eziqhuba ukushisa. Isibonelo, ukusetshenziswa kokuguquguquka kokushisa kwe-SiC kungabonakala ezintweni ezisetshenziswayo zamadivayisi e-semiconductor, izinto ze-ceramic eziqhuba ukushisa okuphezulu, ama-heater nama-heating plates okucubungula ama-semiconductor, izinto ze-capsule ze-nuclear fuel, kanye namasongo okuvala igesi amaphampu e-compressor.
Ukusetshenziswa kwei-silicon carbideensimini ye-semiconductor
Amadiski okugaya kanye nezinto zokulungisa kuyimishini ebalulekile yenqubo yokukhiqizwa kwe-silicon wafer embonini ye-semiconductor. Uma idiski yokugaya yenziwe ngensimbi ephothiwe noma insimbi yekhabhoni, impilo yayo yesevisi imfushane futhi i-coefficient yayo yokukhulisa ukushisa inkulu. Ngesikhathi sokucubungula ama-silicon wafer, ikakhulukazi ngesikhathi sokugaya noma ukupholisha ngesivinini esikhulu, ngenxa yokuguguleka nokuguquguquka kokushisa kwediski yokugaya, ukuqina kanye nokulingana kwe-silicon wafer kunzima ukuqinisekisa. Idiski yokugaya yenziwe ngeizitsha zobumba ze-silicon carbideinokuguga okuncane ngenxa yobunzima bayo obuphezulu, futhi i-coefficient yayo yokwandisa ukushisa ifana kakhulu neye-silicon wafers, ngakho-ke ingagaywa futhi ipholishwe ngesivinini esikhulu.
Ngaphezu kwalokho, lapho kukhiqizwa ama-wafer e-silicon, kudingeka aphathwe ngokushisa okuphezulu futhi avame ukuthuthwa kusetshenziswa izinto zokulungisa i-silicon carbide. Azimelani nokushisa futhi azibhubhisi. I-carbon efana nedayimane (i-DLC) kanye nezinye izembozo zingasetshenziswa ebusweni ukuze kuthuthukiswe ukusebenza, kuncishiswe umonakalo we-wafer, futhi kuvinjelwe ukusabalala kokungcola.
Ngaphezu kwalokho, njengommeleli wezinto ze-semiconductor zesizukulwane sesithathu ze-wide-bandgap semiconductor, izinto ze-silicon carbide single crystal zinezakhiwo ezifana nobubanzi be-bandgap obukhulu (cishe izikhathi ezi-3 kune-Si), ukuhanjiswa kokushisa okuphezulu (cishe izikhathi ezi-3.3 kune-Si noma izikhathi ezi-10 kune-GaAs), izinga lokufuduka kwama-electron saturation eliphezulu (cishe izikhathi ezi-2.5 kune-Si) kanye nensimu kagesi ephukile kakhulu (cishe izikhathi ezi-10 kune-Si noma izikhathi ezi-5 kune-GaAs). Amadivayisi e-SiC alungisa amaphutha amadivayisi ezinto ze-semiconductor zendabuko ekusetshenzisweni okusebenzayo futhi kancane kancane aba yiwona aphambili kuma-semiconductors anamandla.
Isidingo se-silicon carbide ceramics esisebenza ngokushisa okuphezulu sikhuphuke kakhulu
Ngokuthuthuka okuqhubekayo kwesayensi nobuchwepheshe, isidingo sokusetshenziswa kwe-silicon carbide ceramics ensimini ye-semiconductor sikhuphuke kakhulu, futhi ukuhanjiswa okuphezulu kokushisa kuyisibonakaliso esibalulekile sokusetshenziswa kwayo ezingxenyeni zemishini yokukhiqiza i-semiconductor. Ngakho-ke, kubalulekile ukuqinisa ucwaningo lwe-silicon carbide ceramics oluphezulu lokushisa. Ukunciphisa okuqukethwe kwe-lattice oxygen, ukuthuthukisa ubuningi, kanye nokulawula ngokufanele ukusatshalaliswa kwesigaba sesibili ku-lattice yizindlela eziyinhloko zokuthuthukisa ukuhanjiswa kokushisa kwe-silicon carbide ceramics.
Okwamanje, kunezifundo ezimbalwa mayelana nokushisa okuphezulu kwe-silicon carbide ceramics ezweni lakithi, futhi kusenesikhala esikhulu uma kuqhathaniswa nezinga lomhlaba. Iziqondiso zocwaningo zesikhathi esizayo zifaka:
●Qinisa inqubo yokulungiselela ucwaningo lwempuphu ye-silicon carbide ceramic. Ukulungiswa kwempuphu ye-silicon carbide ehlanzekile kakhulu, ephansi komoya-mpilo kuyisisekelo sokulungiselela i-silicon carbide ceramics eqhuba ukushisa okuphezulu;
● Ukuqinisa ukukhethwa kwezinsiza zokusila kanye nocwaningo oluhlobene lwethiyori;
●Qinisa ucwaningo kanye nentuthuko yemishini yokusila ephezulu. Ngokulawula inqubo yokusila ukuze kutholakale isakhiwo esincane esifanele, kuyisimo esidingekayo ukuze kutholakale i-silicon carbide ceramics eqhuba ukushisa okuphezulu.
Izinyathelo zokuthuthukisa ukuqhutshwa kokushisa kwe-silicon carbide ceramics
Isihluthulelo sokuthuthukisa ukuqhutshwa kokushisa kwe-SiC ceramics ukunciphisa imvamisa yokusabalala kwe-phonon nokwandisa indlela ekhululekile ye-phonon. Ukuqhutshwa kokushisa kwe-SiC kuzothuthukiswa ngempumelelo ngokunciphisa i-porosity kanye nobuningi bomngcele wezinhlamvu ze-SiC ceramics, ukuthuthukisa ubumsulwa bemingcele yezinhlamvu ze-SiC, ukunciphisa ukungcola kwe-lattice ye-SiC noma amaphutha e-lattice, nokwandisa isithwali sokudlulisa ukugeleza kokushisa ku-SiC. Njengamanje, ukwenza ngcono uhlobo nokuqukethwe kwezinsiza zokusinta kanye nokwelashwa kokushisa okuphezulu yizinyathelo eziyinhloko zokuthuthukisa ukuqhutshwa kokushisa kwe-SiC ceramics.
① Ukuthuthukisa uhlobo kanye nokuqukethwe kwezinsiza zokusila
Izinsiza ezihlukahlukene zokusinta zivame ukungezwa lapho kulungiswa i-SiC ceramics eqhuba ukushisa okuphezulu. Phakathi kwazo, uhlobo kanye nokuqukethwe kwezinsiza zokusinta kunethonya elikhulu ekuqhubeni ukushisa kwe-SiC ceramics. Isibonelo, izakhi ze-Al noma ze-O ohlelweni lwe-Al2O3 zokusiza ukusinta zincibilika kalula ku-SiC lattice, okuholela ezikhaleni nasezinkingeni, okuholela ekwandeni kwemvamisa yokusabalala kwe-phonon. Ngaphezu kwalokho, uma okuqukethwe kwezinsiza zokusinta kuphansi, izinto kunzima ukuzisinta nokuzidinisa, kuyilapho okuqukethwe okuphezulu kwezinsiza zokusinta kuzoholela ekwandeni kokungcola kanye neziphambeko. Izinsiza zokusinta ngokweqile kwesigaba soketshezi zingase futhi zivimbele ukukhula kwezinhlayiya ze-SiC futhi zinciphise indlela ephakathi nendawo yamahhala yama-phonon. Ngakho-ke, ukuze kulungiselelwe i-SiC ceramics eqhuba ukushisa okuphezulu, kuyadingeka ukunciphisa okuqukethwe kwezinsiza zokusinta ngangokunokwenzeka ngenkathi kuhlangatshezwana nezidingo zokusinta, bese uzama ukukhetha izinsiza zokusinta okunzima ukuzisinta ku-SiC lattice.
*Izakhiwo zokushisa ze-SiC ceramics lapho kufakwa izinsiza ezahlukene zokuthulula
Njengamanje, izitsha zobumba ze-SiC ezicindezelwe ngokushisa ezifakwe i-BeO njengesizo sokushisa zinezinga eliphezulu kakhulu lokushisa kwegumbi (270W·m-1·K-1). Kodwa-ke, i-BeO iyinto enobuthi kakhulu futhi ibangela umdlavuza, futhi ayifanele ukusetshenziswa kabanzi emalabhorethri noma emasimini ezimboni. Iphuzu eliphansi kakhulu le-eutectic lohlelo lwe-Y2O3-Al2O3 lingu-1760℃, okuwusizo oluvamile lwe-liquid-phase sintering lwezitsha zobumba ze-SiC. Kodwa-ke, njengoba i-Al3+ incibilika kalula ku-lattice ye-SiC, lapho lolu hlelo lusetshenziswa njengesizo sokushisa, i-SiC ceramics efudumalayo ingaphansi kuka-200W·m-1·K-1.
Izinto zomhlaba ezingavamile ezifana ne-Y, Sm, Sc, Gd kanye ne-La azincibiliki kalula ku-SiC lattice futhi zinomoya-mpilo ophezulu, okunganciphisa ngempumelelo okuqukethwe komoya-mpilo kwe-SiC lattice. Ngakho-ke, uhlelo lwe-Y2O3-RE2O3 (RE=Sm, Sc, Gd, La) luyinsiza evamile yokuncibilikisa yokulungiselela ukuhanjiswa kokushisa okuphezulu (>200W·m-1·K-1) SiC ceramics. Uma sibheka usizo lokuncibilikisa uhlelo lwe-Y2O3-Sc2O3 njengesibonelo, inani lokuphambuka kwe-ion le-Y3+ kanye ne-Si4+ likhulu, futhi lokhu kokubili akuhlangabezani nesisombululo esiqinile. Ukuncibilika kwe-Sc ku-SiC emsulwa ku-1800~2600℃ kuncane, cishe (2~3)×1017atoms·cm-3.
② Ukwelashwa kokushisa okuphezulu
Ukwelashwa ngokushisa okuphezulu kwe-SiC ceramics kusiza ekuqedeni amaphutha e-lattice, ukuhlukana kanye nokucindezeleka okusele, kukhuthaze ukuguqulwa kwesakhiwo kwezinye izinto ezi-amorphous zibe amakristalu, futhi kwenze buthaka umphumela wokusabalala kwe-phonon. Ngaphezu kwalokho, ukwelashwa ngokushisa okuphezulu kungakhuthaza ngempumelelo ukukhula kwezinhlamvu ze-SiC, futhi ekugcineni kuthuthukise izakhiwo zokushisa zezinto. Isibonelo, ngemuva kokwelashwa ngokushisa okuphezulu ngo-1950°C, i-coefficient yokusabalalisa ukushisa kwe-SiC ceramics yanda kusuka ku-83.03mm2·s-1 kuya ku-89.50mm2·s-1, kanye nokuqhuba ukushisa kwegumbi-lokushisa kwanda kusuka ku-180.94W·m-1·K-1 kuya ku-192.17W·m-1·K-1. Ukwelashwa ngokushisa okuphezulu kuthuthukisa ngempumelelo ikhono lokususa i-oxidation le-sintering aid ebusweni be-SiC kanye ne-lattice, futhi kwenza ukuxhumana phakathi kwezinhlamvu ze-SiC kuqine. Ngemuva kokwelashwa ngokushisa okuphezulu, ukuqhuba ukushisa kwegumbi-lokushisa kwe-SiC ceramics kuthuthukiswe kakhulu.
Isikhathi sokuthunyelwe: Okthoba-24-2024