Okwangoku,i-silicon carbide (i-SiC)sisixhobo se-ceramic esiqhuba ubushushu esifundwa ngokukhutheleyo ekhaya nakwamanye amazwe. Ukuqhuba kobushushu kwe-SiC kuphezulu kakhulu, kwaye ezinye iifom zekristale zinokufikelela kwi-270W/mK, esele ikhokela phakathi kwezinto ezingezizo eziqhuba ubushushu. Umzekelo, ukusetyenziswa kokuqhuba kobushushu be-SiC kunokubonwa kwizixhobo ze-substrate zezixhobo ze-semiconductor, izixhobo ze-ceramic eziqhuba ubushushu obuphezulu, izifudumezi kunye neepleyiti zokufudumeza zokucubungula i-semiconductor, izixhobo ze-capsule ze-nuclear fuel, kunye neendandatho zokutywina igesi kwiimpompo ze-compressor.
Ukusetyenziswa kwei-silicon carbidekwicandelo le-semiconductor
Iidiski zokugaya kunye nezixhobo zokulungisa zizixhobo ezibalulekileyo zenkqubo yokuvelisa i-silicon wafer kwishishini le-semiconductor. Ukuba idiski yokugaya yenziwe ngentsimbi ephothiweyo okanye intsimbi yekhabhoni, ubomi bayo benkonzo bufutshane kwaye i-thermal expansion coefficient yayo inkulu. Ngexesha lokucubungula ii-silicon wafers, ingakumbi ngexesha lokugaya okanye ukupolisha ngesantya esiphezulu, ngenxa yokuguguleka kunye nokuguquguquka kobushushu bediski yokugaya, kunzima ukuqinisekisa ukuba i-silicon wafer iyaguquguquka kwaye iyahambelana. Idiski yokugaya yenziwe ngeiiseramikhi zesilicon carbideAyigugi kakhulu ngenxa yobunzima bayo obuphezulu, kwaye i-thermal expansion coefficient yayo iyafana neyee-silicon wafers, ngoko ke inokugaywa kwaye ipholishwe ngesantya esiphezulu.
Ukongeza, xa kuveliswa ii-wafer ze-silicon, kufuneka ziphathwe ngobushushu obuphezulu kwaye zihlala zithuthwa kusetyenziswa izixhobo ze-silicon carbide. Azinabushushu kwaye azitshabalalisi. I-carbon efana nedayimani (DLC) kunye nezinye izinto zokugquma zinokufakwa kumphezulu ukuphucula ukusebenza, ukunciphisa umonakalo we-wafer, kunye nokuthintela ukusasazeka kongcoliseko.
Ngaphezu koko, njengommeli wezixhobo ze-semiconductor zesizukulwana sesithathu ezibanzi ze-bandgap, izixhobo ze-silicon carbide single crystal zineempawu ezifana nobubanzi be-bandgap enkulu (malunga nezihlandlo ezi-3 ze-Si), ukuhanjiswa kobushushu obuphezulu (malunga nezihlandlo ezi-3.3 ze-Si okanye izihlandlo ezili-10 ze-GaAs), izinga eliphezulu lokufuduka kwe-electron saturation (malunga nezihlandlo ezi-2.5 ze-Si) kunye nentsimi yombane eqhekekileyo kakhulu (malunga nezihlandlo ezili-10 ze-Si okanye izihlandlo ezi-5 ze-GaAs). Izixhobo ze-SiC zilungisa iimpazamo zezixhobo ze-semiconductor zemveli kwizicelo ezisebenzayo kwaye ngokuthe ngcembe ziba yeyona nto iphambili kwii-semiconductors zamandla.
Imfuno ye-silicon carbide ceramics ephezulu yokuqhuba ubushushu inyukile kakhulu
Ngenxa yophuhliso oluqhubekayo lwesayensi netekhnoloji, imfuno yokusetyenziswa kweeseramikhi ze-silicon carbide kwicandelo le-semiconductor inyuke kakhulu, kwaye ukuhanjiswa kobushushu obuphezulu luphawu oluphambili lokusetyenziswa kwayo kwiindawo zokwenza izixhobo ze-semiconductor. Ke ngoko, kubalulekile ukuqinisa uphando malunga nokuhanjiswa kobushushu obuphezulu kweeseramikhi ze-silicon carbide. Ukunciphisa umxholo we-lattice oxygen, ukuphucula uxinano, kunye nokulawula ngokufanelekileyo ukusasazwa kwesigaba sesibini kwi-lattice zezona ndlela ziphambili zokuphucula ukuhanjiswa kobushushu kweeseramikhi ze-silicon carbide.
Okwangoku, zimbalwa izifundo ezenziweyo kwi-silicon carbide ceramics ezisebenzisa ubushushu obuphezulu kwilizwe lam, kwaye kusekho umsantsa omkhulu xa kuthelekiswa nenqanaba lehlabathi. Imiyalelo yophando lwexesha elizayo ibandakanya:
●Qinisa uphando lwenkqubo yokulungiselela umgubo we-silicon carbide ceramic. Ukulungiswa komgubo we-silicon carbide ococekileyo kakhulu, one-oxygen ephantsi sisiseko sokulungiselela umgubo we-silicon carbide ceramics oqhuba ubushushu obuphezulu;
● Ukuqinisa ukhetho lwezixhobo zokucoca kunye nophando oluhambelanayo lwethiyori;
●Qinisa uphando kunye nophuhliso lwezixhobo zokusila ezikumgangatho ophezulu. Ngokulawula inkqubo yokusila ukuze kufunyanwe isakhiwo esifanelekileyo, kuyimfuneko ukufumana iiseramikhi ze-silicon carbide ezisebenzisa ubushushu obuphezulu.
Amanyathelo okuphucula ukuhanjiswa kobushushu kweeseramikhi ze-silicon carbide
Isitshixo sokuphucula ukuhanjiswa kobushushu kweeseramikhi zeSiC kukunciphisa isantya sokusasazeka kwee-phonon kunye nokwandisa indlela ekhululekileyo ye-phonon. Ukuhanjiswa kobushushu kweSiC kuya kuphuculwa ngempumelelo ngokunciphisa ubungqingqwa kunye noxinano lwemida yeeseramikhi zeSiC, ukuphucula ubunyulu bemida yeengqolowa zeSiC, ukunciphisa ukungcola kwe-lattice yeSiC okanye iziphene ze-lattice, kunye nokwandisa isithwali sokuhambisa ukuhamba kobushushu kwiSiC. Okwangoku, ukuphucula uhlobo kunye nomxholo wezixhobo zokusila kunye nonyango lobushushu obuphezulu zezona ndlela ziphambili zokuphucula ukuhanjiswa kobushushu kweeseramikhi zeSiC.
① Ukuphucula uhlobo kunye nomxholo wezixhobo zokucoca
Izixhobo ezahlukeneyo zokusinkcenkceshela zihlala zongezwa xa kulungiswa iiseramikhi zeSiC ezisebenzisa ubushushu obuphezulu. Phakathi kwazo, uhlobo kunye nomxholo wezixhobo zokusinkcenkceshela zinempembelelo enkulu ekuqhubeni kobushushu kweeseramikhi zeSiC. Umzekelo, izinto ze-Al okanye ze-O kwinkqubo ye-Al2O3 ezisebenzisa ugesi zinyibilika lula kwi-lattice yeSiC, nto leyo ekhokelela kwizithuba kunye neziphene, nto leyo ekhokelela ekwandeni kwe-frequency yokusasazeka kwee-phonon. Ukongeza, ukuba umxholo wezixhobo zokusinkcenkceshela uphantsi, izinto kunzima ukuzisinkcenkceshela nokuziqinisa, ngelixa umxholo ophezulu wezixhobo zokusinkcenkceshela uya kukhokelela ekwandeni kokungcola kunye neziphene. Izixhobo zokusinkcenkceshela ezigqithisileyo zesigaba solwelo zinokuthintela ukukhula kweenkozo zeSiC kwaye zinciphise indlela ephakathi yokukhululeka kwee-phonon. Ke ngoko, ukuze kulungiselelwe iiseramikhi zeSiC ezisebenzisa ugesi obuphezulu, kuyimfuneko ukunciphisa umxholo wezixhobo zokusinkcenkceshela kangangoko kunokwenzeka ngelixa kuhlangatyezwana neemfuno zobuninzi bosinkcenkceshela, kwaye uzame ukukhetha izixhobo zokusinkcenkceshela ezinzima ukuzisinkcenkceshela kwi-lattice yeSiC.
*Iimpawu zobushushu ze-SiC ceramics xa kongezwa izixhobo ezahlukeneyo zokuthambisa
Okwangoku, iiseramikhi zeSiC ezicinezelwe ngobushushu ezifakwe iBeO njengesincedisi sokusinyisa zine-conductivity ephezulu yobushushu begumbi (270W·m-1·K-1). Nangona kunjalo, iBeO yinto enobungozi kakhulu kwaye ibangela umhlaza, kwaye ayifanelekanga ukusetyenziswa ngokubanzi kwiilebhu okanye kwiinkalo zoshishino. Indawo ephantsi kakhulu ye-eutectic yenkqubo ye-Y2O3-Al2O3 yi-1760℃, olu luncedo oluqhelekileyo lwe-liquid-phase sintering kwi-SiC ceramics. Nangona kunjalo, ekubeni i-Al3+ inyibilika ngokulula kwi-lattice yeSiC, xa le nkqubo isetyenziswa njengesincedisi sokusinyisa, i-conductivity yobushushu begumbi kwi-SiC ceramics ingaphantsi kwe-200W·m-1·K-1.
Izinto ezinqabileyo zomhlaba ezifana ne-Y, Sm, Sc, Gd kunye ne-La azinyibiliki lula kwi-lattice ye-SiC kwaye zinomoya ophezulu we-oksijini, nto leyo enokunciphisa ngempumelelo umxholo we-oksijini kwi-lattice ye-SiC. Ke ngoko, inkqubo ye-Y2O3-RE2O3 (RE=Sm, Sc, Gd, La) sisixhobo esiqhelekileyo sokuncedisa ukunyibilikisa izinto ekulungiseleleni ukuhanjiswa kobushushu okuphezulu (>200W·m-1·K-1) i-SiC ceramics. Ukuthatha isixhobo sokuncedisa ukunyibilikisa izinto se-Y2O3-Sc2O3 njengomzekelo, ixabiso lokuphambuka kwe-ion le-Y3+ kunye ne-Si4+ likhulu, kwaye ezi zimbini azingeni kwisisombululo esiqinileyo. Ukunyibilika kwe-Sc kwi-SiC ecocekileyo kwi-1800~2600℃ kuncinci, malunga ne-(2~3)×1017atoms·cm-3.
② Unyango lobushushu obuphezulu
Unyango lobushushu obuphezulu lweeseramikhi zeSiC lunceda ekupheliseni iziphene zelattice, ukusasazeka kunye noxinzelelo olushiyekileyo, lukhuthaza ukuguqulwa kwesakhiwo kwezinye izinto ezingafaniyo zibe ziikristale, kwaye buthathaka isiphumo sokusasazeka kwe-phonon. Ukongeza, unyango lobushushu obuphezulu lunokukhuthaza ngempumelelo ukukhula kweenkozo zeSiC, kwaye ekugqibeleni luphucule iipropati zobushushu zezinto. Umzekelo, emva konyango lobushushu obuphezulu kwi-1950°C, i-thermal diffusion coefficient yeeseramikhi zeSiC inyuke ukusuka kwi-83.03mm2·s-1 ukuya kwi-89.50mm2·s-1, kwaye i-thermal conductivity yegumbi inyuke ukusuka kwi-180.94W·m-1·K-1 ukuya kwi-192.17W·m-1·K-1. Unyango lobushushu obuphezulu luphucula ngempumelelo amandla okususa i-oxidation ye-sintering aid kumphezulu weSiC kunye nelattice, kwaye lwenza unxibelelwano phakathi kweenkozo zeSiC lube lukhuni ngakumbi. Emva konyango lobushushu obuphezulu, i-thermal conductivity yegumbi yeeseramikhi zeSiC iphuculwe kakhulu.
Ixesha leposi: Oktobha-24-2024