Kwi-silicon carbide enye inkqubo yokukhula kwekristale, ukuthuthwa komphunga womzimba yeyona ndlela yangoku yoshishino. Kwindlela yokukhula yePVT,i-silicon carbide powderinempembelelo enkulu kwinkqubo yokukhula. Zonke iiparamitha zei-silicon carbide powderichaphazela ngqo umgangatho wokukhula kwekristale enye kunye neempawu zombane. Kwizicelo zamashishini zangoku, ezisetyenziswa ngokuqhelekileyoi-silicon carbide powderinkqubo yodibaniso yindlela yokuzikhulisa yobushushu obuphezulu.
I-self-propagating high-temperature synthesis method isebenzisa ubushushu obuphezulu ukunika i-reactants ubushushu bokuqala ukuqala ukusabela kweekhemikhali, ize isebenzise eyayo ikhemikhali yokusabela ubushushu ukuvumela izinto ezingaphendulwanga ukuba ziqhubeke nokugqiba ukusabela kweekhemikhali. Nangona kunjalo, ekubeni i-chemical reaction ye-Si kunye ne-C ikhupha ukushisa okuncinci, ezinye ii-reactants kufuneka zongezwe ukugcina ukusabela. Ke ngoko, abaphengululi abaninzi baye bacebisa indlela ephuculweyo yokwenziwa kwe-self-propagating synthesis kwesi siseko, ukwazisa isivusi. Indlela yokuzisasaza kulula ukuyiphumeza, kwaye iiparamitha ezahlukeneyo zokudibanisa kulula ukuzinza ukulawula. I-synthesis enkulu ihlangabezana neemfuno zoshishino.
Kwangoko ngo-1999, iBridgeport yasebenzisa indlela yokuzisasaza yobushushu obuphezulu ukudibanisa.SiC powder, kodwa yasebenzisa i<em>ethoxysilane nephenol resin njengezinto ezisetyenziswayo, nto leyo eyayibiza imali eninzi. I-Gao Pan kunye nabanye basebenzisa i-Si powder ephezulu kunye ne-C powder njengezinto ezisetyenziswayo ukudibanisaSiC powderngokusabela kobushushu obuphezulu kwi-argon atmosphere. UNing Lina ulungiselele-isuntswana elikhuluSiC powderngokuhlanganiswa kwesibini.
I-medium-frequency induction heat furnace ephuhliswe yiSecond Research Institute of China Electronics Technology Group Corporation ixuba ngokulinganayo umgubo wesilicon kunye nomgubo wekhabhoni kumlinganiselo othile we-stoichiometric kwaye uzibeke kwicrucible yegraphite. Ii-graphite crucibleibekwe kwi-medium-frequency induction yokufudumeza isithando sokufudumala, kwaye utshintsho lobushushu lusetyenziselwa ukudibanisa kunye nokuguqula isigaba sobushushu obuphantsi kunye nesigaba sobushushu esiphezulu se-silicon carbide ngokulandelanayo. Ekubeni iqondo lokushisa le-β-SiC ye-synthesis reaction kwisigaba esisezantsi seqondo lokushisa liphantsi kunokushisa kwe-volatilization ye-Si, i-synthesis ye-β-SiC phantsi kwe-vacuum ephezulu inokuqinisekisa kakuhle u-self-propagation. Indlela yokwazisa i-argon, i-hydrogen kunye ne-HCl igesi kwi-synthesis ye-α-SiC inqanda ukubolaSiC powderkwinqanaba eliphezulu lobushushu, kwaye unokunciphisa ngokufanelekileyo umxholo we-nitrogen kwi-α-SiC powder.
UShandong Tianyue wayila iziko lokudibanisa, esebenzisa igesi ye-silane njenge-silicon ekrwada kunye nomgubo wekhabhoni njengemathiriyeli ekrwada yekhabhoni. Isixa segesi ekrwada esaziswayo sahlengahlengiswa ngamanyathelo amabini, kwaye ubungakanani bokugqibela be-silicon carbide obuhlanganisiweyo buphakathi kwe-50 kunye ne-5 000 um.
Izinto ezi-1 zokulawula inkqubo ye powder synthesis
1.1 Isiphumo sobungakanani besuntswana lomgubo ekukhuleni kwekristale
Ubungakanani besuntswana le-silicon carbide powder linempembelelo ebaluleke kakhulu ekukhuleni kwekristale enye elandelayo. Ukukhula kwekristale ye-SiC enye nge-PVT kufezekiswa ikakhulu ngokuguqula umlinganiselo we-silicon kunye nekhabhoni kwicandelo lesigaba segesi, kwaye umlinganiselo we-silicon kunye nekhabhoni kwicandelo lesigaba segesi unxulumene nobungakanani besuntswana le-silicon carbide powder. . Uxinzelelo olupheleleyo kunye ne-silicon-carbon ratio yenkqubo yokukhula inyuka kunye nokuncipha kobukhulu be-particle. Xa ubukhulu be-particle buyancipha ukusuka kwi-2-3 mm ukuya kwi-0.06 mm, umlinganiselo we-silicon-carbon ukhula ukusuka kwi-1.3 ukuya kwi-4.0. Xa iincinci zincinci ukuya kwinqanaba elithile, uxinzelelo lwe-Si luyanda, kwaye uluhlu lwefilimu yeSi lwenziwa phezu kwekristale ekhulayo, ikhuthaza ukukhula kwe-gas-liquid-solid, echaphazela i-polymorphism, iziphene zamanqaku kunye neziphene zomgca. kwikristale. Ngoko ke, ubungakanani be-particle ye-high-purity silicon carbide powder kufuneka ilawulwe kakuhle.
Ukongezelela, xa ubukhulu be-SiC powder particles buncinci, i-powder iyancipha ngokukhawuleza, ibangele ukukhula okugqithisileyo kwe-crystals eyodwa ye-SiC. Ngakolunye uhlangothi, kwindawo yobushushu obuphezulu be-SiC yokukhula kwekristale enye, iinkqubo ezimbini ze-synthesis kunye nokubola zenziwa ngaxeshanye. I-silicon carbide powder iya kubola kwaye yenze i-carbon kwisigaba segesi kunye nesigaba esiqinileyo njengeSi, i-Si2C, i-SiC2, okubangelwa i-carbonization enzulu ye-polycrystalline powder kunye nokwakhiwa kwe-carbon inclusions kwi-crystal; kwelinye icala, xa izinga lokubola komgubo likhawuleza ngokukhawuleza, isakhiwo sekristale ye-crystal ye-SiC ekhulile iyakwazi ukutshintsha, okwenza kube nzima ukulawula umgangatho we-crystal ye-SiC ekhulile.
1.2 Impembelelo yefom yekristale yomgubo ekukhuleni kwekristale
Ukukhula kwe-crystal ye-SiC enye nge-PVT indlela yinkqubo ye-sublimation-recrystallization kwiqondo lokushisa eliphezulu. Ifom ye-crystal ye-SiC ye-raw material inempembelelo ebalulekileyo ekukhuleni kwekristale. Kwinkqubo ye-powder synthesis, i-low-temperature synthesis phase (β-SiC) kunye nesakhiwo se-cubic yeyunithi yeyunithi kunye nesigaba se-high-temperature synthesis (α-SiC) kunye nesakhiwo se-hexagonal seyunithi yeyunithi iya kuveliswa kakhulu. . Zininzi iifom ze-silicon carbide crystal kunye noluhlu oluncinci lokulawula ubushushu. Umzekelo, i-3C-SiC iya kuguqula ibe yi-hexagonal silicon carbide polymorph, okt 4H / 6H-SiC, kumaqondo obushushu angaphezu kwe-1900 ° C.
Ngethuba lenkqubo yokukhula kwe-crystal eyodwa, xa i-β-SiC powder isetyenziselwa ukukhula i-crystals, i-silicon-carbon molar ratio inkulu kune-5.5, ngelixa i-α-SiC powder isetyenziselwa ukukhula i-crystals, i-silicon-carbon molar ratio yi-1.2. Xa iqondo lokushisa liphakama, ukuguquka kwesigaba kwenzeka kwi-crucible. Ngeli xesha, umlinganiselo we-molar kwisigaba segesi uba mkhulu, ongabalulekanga ekukhuleni kwekristale. Ukongezelela, ezinye izinto ezingcolileyo zesigaba segesi, kuquka i-carbon, i-silicon, kunye ne-silicon dioxide, zenziwe lula ngexesha lenkqubo yokuguqulwa kwesigaba. Ubukho bobu kungcola bubangela ukuba ikristale ivelise i-microtubes kunye ne-voids. Ngoko ke, ifom ye-crystal powder kufuneka ilawulwe ngokuchanekileyo.
1.3 Impembelelo yokungcola komgubo ekukhuleni kwekristale
Umxholo ongcolileyo kwi-SiC powder uchaphazela i-nucleation ezenzekelayo ngexesha lokukhula kwe-crystal. Ukuphakama komxholo wokungcola, kuncinci ukuba ikristale izenzele i-nucleate. Kwi-SiC, ukungcola okuphambili kwesinyithi kubandakanya i-B, i-Al, i-V, kunye ne-Ni, enokuthi ifakwe ngezixhobo zokusebenza ngexesha lokucubungula i-silicon powder kunye ne-carbon powder. Phakathi kwazo, i-B kunye ne-Al zezona nqanaba lamandla angekho nzulu lokwamkela ukungcola kwi-SiC, okukhokelela ekunciphiseni kokumelana ne-SiC. Okunye ukungcola kwesinyithi kuya kuzisa amanqanaba amaninzi ombane, okukhokelela kwiipropati zombane ezingazinzanga ze-SiC iikristale enye kumaqondo okushisa aphezulu, kwaye ibe nefuthe elikhulu kwiipropati zombane ze-high-purity semi-insulating single substrates ye-crystal, ngakumbi i-resistivity. Ke ngoko, ucoceko oluphezulu lwe-silicon carbide powder kufuneka ludityaniswe kangangoko kunokwenzeka.
1.4 Impembelelo yesiqulatho senitrogen kumgubo ekukhuleni kwekristale
Umgangatho womxholo we-nitrogen umisela ukuxhathisa kwe-crystal substrate enye. Abavelisi abakhulu kufuneka bahlengahlengise i-nitrogen doping concentration kwi-synthetic material ngokwenkqubo yokukhula kwe-crystal ekhulile ngexesha lokwenziwa kwe powder. Ucoceko oluphezulu lwe-semi-insulating ye-silicon carbide enye i-crystal substrates zezona zixhobo zithembisayo kwizinto ezingundoqo zomkhosi we-elektroniki. Ukukhulisa i-high-purity semi-insulating single crystal substrates kunye ne-resistivity ephezulu kunye neempawu ezibalaseleyo zombane, umxholo we-nitrogen engcolileyo kwi-substrate kufuneka ilawulwe kwinqanaba eliphantsi. I-conductive ye-crystal substrates enye ifuna umxholo we-nitrogen ukuba ulawulwe kugxininiso oluphezulu.
I-2 iteknoloji yolawulo oluphambili lwe-powder synthesis
Ngenxa yeendawo ezahlukeneyo zokusetyenziswa kwee-silicon carbide substrates, itekhnoloji yokudibanisa umgubo wokukhula nayo ineenkqubo ezahlukeneyo. Kuhlobo lwe-N-uhlobo oluqhubela phambili lwe-crystal powders, ukucoceka okuphezulu kunye nesigaba esisodwa siyafuneka; ngelixa i-semi-insulating enye ye-crystal powders yokukhula, ulawulo olungqongqo lwesiqulatho se-nitrogen luyafuneka.
2.1 Ulawulo lobungakanani besuntswana lomgubo
2.1.1 Ubushushu be-Synthesis
Ukugcina ezinye iimeko zenkqubo zingatshintshanga, iipowders ze-SiC eziveliswe kumaqondo okushisa e-synthesis ye-1900 ℃, i-2000 ℃, i-2100 ℃, kunye ne-2200 ℃ isampuli kwaye ihlalutywe. Njengoko kuboniswe kwi-Figure 1, kunokubonwa ukuba ubungakanani be-particle yi-250 ~ 600 μm kwi-1900 ℃, kwaye ubungakanani bamasuntswana bunyuka ukuya ku-600 ~ 850 μm kwi-2000 ℃, kwaye ubungakanani bamasuntswana buguquka kakhulu. Xa iqondo lokushisa liqhubeka nokunyuka ukuya kwi-2100 ℃, ubungakanani be-particle ye-SiC powder yi-850 ~ 2360 μm, kwaye ukwanda kudla ukuba mnene. Ubungakanani besuntswana le-SiC kwi-2200 ℃ lizinzile malunga ne-2360 μm. Ukunyuka kweqondo lokushisa kwi-synthesis ukusuka kwi-1900 ℃ kunefuthe elihle kwisayizi ye-particle ye-SiC. Xa ubushushu be-synthesis buqhubeka bukhula ukusuka kwi-2100 ℃, ubungakanani besuntswana abusatshintshi kakhulu. Ke ngoko, xa iqondo lobushushu le-synthesis limiselwe kwi-2100 ℃, ubungakanani besuntswana elikhulu linokwakheka kusetyenziso olusezantsi lwamandla.
2.1.2 Ixesha lokudibanisa
Ezinye iimeko zenkqubo zihlala zingatshintshi, kwaye ixesha lokudibanisa libekwe kwi-4 h, 8 h, kunye ne-12 h ngokulandelanayo. Uhlalutyo lwesampula lwe-SiC oluveliswayo lwe-powder luboniswe kwi-Figure 2. Kufunyenwe ukuba ixesha lokudibanisa linempembelelo ebalulekileyo kwi-particle size ye-SiC. Xa ixesha le-synthesis liyi-4 h, ubukhulu be-particle ubukhulu busasazwa kwi-200 μm; xa ixesha le-synthesis liyi-8 h, ubungakanani bamasuntswana okwenziwa buyanda kakhulu, busasazwa kakhulu malunga ne-1 000 μm; njengoko ixesha le-synthesis liqhubeka likhula, ubungakanani bamasuntswana buyanda ngakumbi, busasazwa kakhulu malunga ne-2 000 μm.
2.1.3 Impembelelo yesayizi yesuntswana lemathiriyeli ekrwada
Njengoko ikhonkco lemveliso ye-silicon yasekhaya iphuculwa ngokuthe ngcembe, ukucoceka kwezinto ze-silicon nako kuphuculwa ngakumbi. Okwangoku, izinto ze-silicon ezisetyenziswa kwi-synthesis zahlulwe kakhulu kwi-silicon yegranular kunye ne-silicon engumgubo, njengoko kubonisiwe kuMfanekiso 3.
Izixhobo ezahlukeneyo ze-silicon zisetyenziselwe ukuqhuba iimvavanyo ze-silicon carbide synthesis. Ukuthelekiswa kweemveliso zokwenziwa kuboniswe kuMzobo 4. Uhlalutyo lubonisa ukuba xa usebenzisa i-block silicon izinto eziluhlaza, inani elikhulu lezinto zeSi zikhona kwimveliso. Emva kokuba ibhloko ye-silicon ityunyuziwe okwesibini, i-Si element kwimveliso eyenziwe yancitshiswa kakhulu, kodwa isekhona. Ekugqibeleni, i-silicon powder isetyenziselwa ukudibanisa, kwaye kuphela i-SiC ekhoyo kwimveliso. Oku kungenxa yokuba kwinkqubo yokuvelisa, ubungakanani obukhulu be-silicon yegranular kufuneka buqale ukusabela kwi-surface synthesis yokuqala, kwaye i-silicon carbide idityaniswe phezulu, ethintela i-Si powder yangaphakathi ukuba idibanise ngakumbi ne-C powder. Ke ngoko, ukuba i-silicon yebhloko isetyenziswa njengezinto ezikrwada, kufuneka ichithwe kwaye emva koko ithotyelwe inkqubo yesibini yokufumana i-silicon carbide powder yokukhula kwekristale.
2.2 Ulawulo lwefom yekristale yomgubo
2.2.1 Impembelelo yobushushu bokudibanisa
Ukugcina ezinye iimeko zenkqubo zingatshintshwanga, ubushushu be-synthesis yi-1500 ℃, 1700 ℃, 1900 ℃, kunye ne-2100 ℃, kunye ne-SiC powder eyenziwe isampuli kwaye ihlalutywe. Njengoko kubonisiwe kuMfanekiso 5, i-β-SiC inomhlaba omthubi, kwaye i-α-SiC ikhaphukhaphu ngombala. Ngokujonga umbala kunye ne-morphology yomgubo owenziweyo, kunokumiselwa ukuba imveliso eyenziwe yi-β-SiC kumaqondo obushushu e-1500℃ kunye ne-1700℃. Kwi-1900℃, umbala uba lula, kwaye iinqununu ze-hexagonal zivela, ezibonisa ukuba emva kokunyuka kweqondo lokushisa ukuya kwi-1900℃, ukuguquka kwesigaba kwenzeka, kwaye inxalenye ye-β-SiC iguqulwa ibe yi-α-SiC; xa iqondo lokushisa liqhubeka nokunyuka ukuya kwi-2100 ℃, kufumaniseka ukuba amasuntswana ahlanganisiweyo ayabonakala, kwaye i-α-SiC iguqulwe ngokusisiseko.
2.2.2 Isiphumo sexesha lokudibanisa
Ezinye iimeko zenkqubo zihlala zingatshintshi, kwaye ixesha lokudibanisa libekwe kwi-4h, 8h, kunye ne-12h, ngokulandelanayo. I-powder ye-SiC eyenziwe isampuli kwaye ihlalutywe yi-diffractometer (XRD). Iziphumo ziboniswe kuMfanekiso 6. Ixesha lokudibanisa linempembelelo ethile kwimveliso eyenziwe yi-SiC powder. Xa ixesha le-synthesis liyi-4 h kunye ne-8 h, imveliso yokwenziwa ikakhulu yi-6H-SiC; xa ixesha le-synthesis liyi-12 h, i-15R-SiC ibonakala kwimveliso.
2.2.3 Impembelelo yomlinganiselo wempahla ekrwada
Ezinye iinkqubo zihlala zingatshintshi, inani lezinto ze-silicon-carbon zihlaziywa, kwaye izilinganiso ziyi-1.00, 1.05, 1.10 kunye ne-1.15 ngokulandelanayo kwiimvavanyo ze-synthesis. Iziphumo ziboniswe kuMfanekiso 7.
Ukusuka kwi-spectrum ye-XRD, kunokubonwa ukuba xa umlinganiselo we-silicon-carbon mkhulu kune-1.05, i-Si engaphezulu ibonakala kwimveliso, kwaye xa i-silicon-carbon ratio ingaphantsi kwe-1.05, i-C engaphezulu ibonakala. Xa umlinganiselo we-silicon-carbon u-1.05, i-carbon yamahhala kwimveliso yokwenziwa ikhutshwe ngokusisiseko, kwaye akukho silicon yamahhala ibonakala. Ngoko ke, umlinganiselo we-silicon-carbon ratio kufuneka ube yi-1.05 ukudibanisa i-SiC ephezulu-yobunyulu.
2.3 Ukulawulwa komthamo wenitrogen ephantsi kumgubo
2.3.1 Iimathiriyeli ekrwada zokwenziwa
Izinto ezisetyenziswayo kolu vavanyo ziyi-powder ecocekileyo yekhabhoni kunye ne-silicone powder ecocekileyo kunye nobubanzi obuphakathi kwe-20 μm. Ngenxa yobungakanani bamasuntswana amancinci kunye nendawo enkulu yendawo ethile, kulula ukufunxa i-N2 emoyeni. Xa udibanisa umgubo, uya kuziswa kwi-crystal form of powder. Ukukhula kweekristale zohlobo lwe-N, i-doping engalinganiyo ye-N2 kwipowder ikhokelela ekuchaseni okungalinganiyo kwe-crystal kunye nokutshintsha kwifom ye-crystal. Umxholo we-nitrogen womgubo owenziweyo emva kokuba i-hydrogen ingeniswe iphantsi kakhulu. Oku kungenxa yokuba umthamo weemolekyuli zehydrogen zincinci. Xa i-N2 ibhengezwa kwi-carbon powder kunye ne-silicon powder ishushu kwaye ibolile ukusuka phezulu, i-H2 isasazeka ngokupheleleyo kwisithuba phakathi kweepowder kunye nomthamo wayo omncinci, ithatha indawo ye-N2, kunye ne-N2 ibalekela kwi-crucible ngexesha lenkqubo yokucoca, ukuphumeza injongo yokususa umxholo wenitrogen.
2.3.2 Inkqubo yokudibanisa
Ngexesha lokwenziwa kwe-silicon carbide powder, ekubeni i-radius ye-athomu ye-carbon kunye ne-athomu ye-nitrogen iyafana, i-nitrogen iya kuthatha indawo yezithuba zekhabhoni kwi-silicon carbide, ngaloo ndlela ikhulise umxholo we-nitrogen. Le nkqubo yokuhlola ithatha indlela yokwazisa i-H2, kwaye i-H2 isabela ngekhabhoni kunye ne-silicon elements kwi-synthesis crucible ukuvelisa i-C2H2, i-C2H, kunye ne-SiH gases. Umxholo wekhabhoni uyanda ngokugqithiswa kwesigaba segesi, ngaloo ndlela kunciphisa izithuba zekhabhoni. Injongo yokususa i-nitrogen ifezekisiwe.
2.3.3 Inkqubo yolawulo lwesiqulatho senitrogen
I-Graphite crucibles ene-porosity enkulu ingasetyenziselwa njengemithombo eyongezelelweyo yeC ukufunxa umphunga weSi kumacandelo esigaba segesi, ukunciphisa iSi kumacandelo esigaba segesi, kwaye ngaloo ndlela ukwandisa iC / Si. Kwangaxeshanye, iicrucibles zegraphite zinokusabela kunye ne-Si atmosphere ukuvelisa i-Si2C, i-SiC2 kunye ne-SiC, elingana nomoya we-Si ezisa umthombo we-C ukusuka kwi-graphite crucible ukuya kwi-atmosfera yokukhula, ukwandisa umlinganiselo we-C, kunye nokwandisa umlinganiselo we-carbon-silicon. . Ngoko ke, umlinganiselo we-carbon-silicon unokunyuswa ngokusebenzisa i-graphite crucibles kunye ne-porosity enkulu, ukunciphisa izithuba zekhabhoni, kunye nokufezekisa injongo yokususa i-nitrogen.
3 Uhlalutyo kunye noyilo lwenkqubo ye-crystal powder synthesis enye
3.1 Umgaqo kunye noyilo lwenkqubo yokudibanisa
Ngolu phando lukhankanywe ngasentla olubanzi malunga nokulawulwa kobungakanani be-particle, ifom ye-crystal kunye nomxholo we-nitrogen we-powder synthesis, inkqubo yokudibanisa iphakanyisiwe. I-high-purity C powder kunye ne-Si powder zikhethiweyo, kwaye zixutywe ngokulinganayo kwaye zilayishwe kwi-graphite crucible ngokwe-silicon-carbon ratio ye-1.05. Amanyathelo enkqubo ahlulwe kakhulu abe ngamanqanaba amane:
I-1) Inkqubo ye-denitrification ephantsi yokushisa, i-vacuuming kwi-5 × 10-4 Pa, emva koko ingenisa i-hydrogen, yenza uxinzelelo lwegumbi malunga ne-80 kPa, igcine i-15 min, kwaye iphinda iphindwe kane. Le nkqubo inokususa izinto ze-nitrogen kumphezulu we-carbon powder kunye ne-silicon powder.
I-2) Inkqubo yokushisa i-denitrification ephezulu, i-vacuuming ukuya kwi-5 × 10-4 Pa, emva koko ifudumeza ukuya kwi-950 ℃, ize ingenise i-hydrogen, yenza uxinzelelo lwegumbi malunga ne-80 kPa, igcine i-15 min, kwaye iphinda iphindwe kane. Le nkqubo inokususa izinto ze-nitrogen kumphezulu we-carbon powder kunye ne-silicon powder, kwaye iqhube i-nitrogen kwindawo yobushushu.
3) Ukuhlanganiswa kwenkqubo yesigaba sobushushu obuphantsi, phuma kwi-5 × 10-4 Pa, emva koko ubushushu ukuya kwi-1350 ℃, gcina iiyure ezili-12, uze uqalise i-hydrogen ukwenza uxinzelelo lwegumbi malunga ne-80 kPa, gcina iyure eli-1. Le nkqubo inokususa i-nitrogen eguquguqukayo ngexesha lenkqubo yokudibanisa.
I-4) I-synthesis yenkqubo yesigaba sokushisa okuphezulu, gcwalisa umlinganiselo othile wokuhamba kwegesi yegesi yokucoceka okuphezulu kwe-hydrogen kunye ne-argon yegesi edibeneyo, yenza uxinzelelo lwegumbi malunga ne-80 kPa, uphakamise ubushushu kwi-2100 ℃, ugcine iiyure ezili-10. Le nkqubo igqiba ukuguqulwa kwe-silicon carbide powder ukusuka kwi-β-SiC ukuya kwi-α-SiC kwaye igqibe ukukhula kweengqungquthela zekristale.
Ekugqibeleni, linda ukushisa kwegumbi ukuba kuphole kwiqondo lokushisa, gcwalisa uxinzelelo lwe-atmospheric, kwaye uthathe umgubo.
3.2 Inkqubo yokwenziwa komgubo emva kokulungiswa
Emva kokuba i powder yenziwe yinkqubo engentla, kufuneka iqhutywe emva kokuba isuse i-carbon yamahhala, i-silicon kunye nezinye izinto ezingcolileyo zetsimbi kunye nokukhusela ubungakanani bamasuntswana. Okokuqala, i-powder synthesized ifakwe kwibhola yebhola yokutyumza, kwaye i-silicon carbide powder echotshoziweyo ifakwe kwi-furnace ye-muffle kwaye ishushu kwi-450 ° C nge-oxygen. Ikhabhoni yamahhala kwipowder i-oxidized ngokushisa ukuvelisa i-carbon dioxide gas ephuma kwigumbi, ngaloo ndlela ifezekisa ukususwa kwekhabhoni yamahhala. Emva koko, i-acidic yokucoca i-liquid ilungiswa kwaye ifakwe kumatshini wokucoca i-silicon carbide yokucoca ukususa i-carbon, i-silicon kunye nokungcola kwetsimbi okushiyekileyo okwenziwa ngexesha lenkqubo yokudibanisa. Emva koko, i-asidi eseleyo ihlanjwe emanzini acocekileyo kwaye yomiswe. I-powder eyomileyo ihlolwe kwisikrini esishukumisayo sokukhethwa kwesayizi ye-particle yokukhula kwekristale.
Ixesha lokuposa: Aug-08-2024