Enqubweni yokukhula kwekristalu eyodwa ye-silicon carbide, ukuthuthwa komhwamuko obonakalayo kuyindlela yamanje yokwenziwa kwezimboni. Indlela yokukhula ye-PVT,i-silicon carbide powderinethonya elikhulu enqubweni yokukhula. Wonke amapharamitha wei-silicon carbide powderkuthinta ngqo ikhwalithi yokukhula kwekristalu eyodwa kanye nezakhiwo zikagesi. Kuzicelo zamanje zezimboni, ezivame ukusetshenziswai-silicon carbide powderI-synthesis process iyindlela yokuhlanganisa yokushisa ephezulu ezisakazayo.
Indlela yokuhlanganisa yokushisa ephezulu ezisakaza yona isebenzisa izinga lokushisa eliphezulu ukuze inikeze ama-reactants ukushisa kokuqala ukuze kuqale ukusabela kwamakhemikhali, bese isebenzisa ukushisa kwayo kwamakhemikhali ukuze ivumele izinto ezingaphenduliwe ukuthi ziqhubeke nokuqedela ukusabela kwamakhemikhali. Nokho, njengoba ukusabela kwamakhemikhali ka-Si no-C kukhipha ukushisa okuncane, ezinye izinto ezisabelayo kufanele zengezwe ukuze kugcinwe ukusabela. Ngakho-ke, osolwazi abaningi bahlongoze indlela ethuthukisiwe yokuzizabalalisa ngokwalo kulesi sisekelo, yethula isiqalisi. Indlela yokuzisakaza kulula ukuyisebenzisa, futhi imingcele ehlukahlukene yokuhlanganisa kulula ukuyilawula ngokuzinzile. I-synthesis enkulu ihlangabezana nezidingo zemboni.
Kusukela ngo-1999, i-Bridgeport yasebenzisa indlela yokuzisakaza yokushisa ephezulu ukuze ihlanganise.I-SiC powder, kodwa yasebenzisa i-ethoxysilane ne-phenol resin njengezinto zokusetshenziswa, okwakubiza kakhulu. I-Gao Pan nabanye basebenzisa i-Si powder ehlanzekile kakhulu ne-C powder njengezinto ezingavuthiwe ukuze bahlanganiseI-SiC powderngokusabela kwezinga lokushisa eliphezulu endaweni ye-argon. UNing Lina walungisa inhlayiya enkuluI-SiC powderngokuhlanganiswa kwesibili.
I-medium-frequency induction heatrnace eyakhiwe yi-Second Research Institute of China Electronics Technology Group Corporation ixuba ngokulinganayo impushana ye-silicon ne-carbon powder esilinganisweni esithile se-stoichiometric bese ikubeka ku-crucible ye-graphite. Ii-graphite crucibleibekwe esithandweni sokushisa esiphakathi kwama-medium-frequency induction for heat, futhi ukuguqulwa kwezinga lokushisa kusetshenziselwa ukuhlanganisa nokuguqula isigaba sezinga lokushisa eliphansi kanye nesigaba sokushisa okuphezulu kwe-silicon carbide ngokulandelanayo. Njengoba izinga lokushisa le-β-SiC synthesis reaction esigabeni sezinga lokushisa eliphansi liphansi kunokushisa kwe-volatilization ye-Si, ukuhlanganiswa kwe-β-SiC ngaphansi kwe-vacuum ephezulu kungaqinisekisa kahle ukuzisakaza. Indlela yokwethula i-argon, i-hydrogen ne-HCl igesi ekuhlanganiseni kwe-α-SiC ivimbela ukubolaI-SiC powderesiteji sokushisa okuphezulu, futhi inganciphisa ngokuphumelelayo okuqukethwe kwe-nitrogen ku-α-SiC powder.
UShandong Tianyue waklama isithando somlilo sokuhlanganiswa, esebenzisa igesi ye-silane njenge-silicon eluhlaza kanye ne-carbon powder njenge-carbon eluhlaza. Inani legesi yempahla eluhlaza eyethulwa lalungiswa ngendlela yezinyathelo ezimbili, futhi usayizi wokugcina wezinhlayiyana ze-silicon carbide wawuphakathi kuka-50 no-5 000 um.
1 Ukulawula izici zenqubo ye-powder synthesis
1.1 Umthelela wosayizi wezinhlayiyana zempushana ekukhuleni kwekristalu
Usayizi wezinhlayiyana ze-silicon carbide powder unethonya elibaluleke kakhulu ekukhuleni kwekristalu eyodwa okulandelayo. Ukukhula kwe-SiC single crystal ngendlela ye-PVT kutholakala ngokuyinhloko ngokushintsha isilinganiso se-molar ye-silicon ne-carbon engxenyeni yesigaba segesi, futhi isilinganiso se-molar ye-silicon ne-carbon engxenyeni yesigaba segesi ihlobene nosayizi wezinhlayiyana ze-silicon carbide powder. . Ingqikithi yokucindezela ne-silicon-carbon ratio yesistimu yokukhula ikhula ngokuncipha kosayizi wezinhlayiyana. Lapho usayizi wezinhlayiyana wehla usuka ku-2-3 mm uye ku-0.06 mm, isilinganiso se-silicon-carbon sikhuphuka sisuka ku-1.3 siye ku-4.0. Lapho izinhlayiya zincane ngokwezinga elithile, ukucindezela kwengxenye ye-Si kuyanda, futhi ungqimba lwefilimu ye-Si kwakheka ebusweni bekristalu ekhulayo, okudala ukukhula okuqinile kwe-gas-liquid-solid, okuthinta i-polymorphism, amaphuzu amaphutha kanye nokukhubazeka komugqa. kukristalu. Ngakho-ke, ubukhulu bezinhlayiyana ze-high-purity silicon carbide powder kumele ilawulwe kahle.
Ukwengeza, lapho ubukhulu bezinhlayiya ze-SiC powder buncane, i-powder ibola ngokushesha, okuholela ekukhuleni ngokweqile kwamakristalu e-SiC eyodwa. Ngakolunye uhlangothi, endaweni yokushisa ephezulu ye-SiC yokukhula kwekristalu eyodwa, izinqubo ezimbili zokuhlanganiswa nokubola zenziwa ngesikhathi esisodwa. I-silicon carbide powder izobola futhi yenze i-carbon esigabeni segesi kanye nesigaba esiqinile njenge-Si, Si2C, i-SiC2, okuholela ku-carbonization engathí sina ye-polycrystalline powder kanye nokwakhiwa kwe-carbon inclusions ku-crystal; ngakolunye uhlangothi, lapho izinga lokubola kwe-powder lishesha kakhulu, isakhiwo se-crystal se-crystal SiC esikhulile sijwayele ukushintsha, okwenza kube nzima ukulawula ikhwalithi ye-SiC single crystal ekhulile.
1.2 Umthelela wefomu le-powder crystal ekukhuleni kwekristalu
Ukukhula kwe-SiC single crystal ngendlela ye-PVT kuyinqubo ye-sublimation-recrystallization ekushiseni okuphezulu. Ifomu lekristalu le-SiC impahla eluhlaza linethonya elibalulekile ekukhuleni kwekristalu. Enqubweni ye-powder synthesis, isigaba se-low-temperature synthesis (β-SiC) esinesakhiwo se-cubic seyunithi yeyunithi kanye nesigaba se-high-temperature synthesis (α-SiC) esinesakhiwo esiyi-hexagonal seyunithi yeyunithi izokhiqizwa ikakhulukazi. . Kunamafomu amaningi e-silicon carbide crystal kanye nebanga elincane lokulawula izinga lokushisa. Isibonelo, i-3C-SiC izoshintsha ibe yi-hexagonal silicon carbide polymorph, okungukuthi 4H/6H-SiC, emazingeni okushisa angaphezu kuka-1900°C.
Phakathi nenqubo yokukhula kwe-crystal eyodwa, lapho i-β-SiC powder isetshenziselwa ukukhulisa amakristalu, isilinganiso se-silicon-carbon molar sikhulu kune-5.5, kuyilapho i-α-SiC powder isetshenziselwa ukukhulisa amakristalu, isilinganiso se-silicon-carbon molar yi-1.2. Lapho izinga lokushisa likhuphuka, ukuguqulwa kwesigaba kwenzeka ku-crucible. Ngalesi sikhathi, isilinganiso se-molar esigabeni segesi siba sikhulu, esingahambisani nokukhula kwekristalu. Ngaphezu kwalokho, okunye ukungcola kwesigaba segesi, okuhlanganisa i-carbon, i-silicon, ne-silicon dioxide, kwenziwa kalula ngesikhathi senqubo yokuguqulwa kwesigaba. Ukuba khona kwalokhu kungcola kubangela ukuthi ikristalu ikhiqize ama-microtube nama-voids. Ngakho-ke, ifomu le-powder crystal kufanele lilawulwe ngokunembile.
1.3 Umthelela wokungcola okuyimpushana ekukhuleni kwekristalu
Okuqukethwe ukungcola ku-SiC powder kuthinta i-nucleation ezenzakalelayo ngesikhathi sokukhula kwekristalu. Uma kuphakeme okuqukethwe ukungcola, mancane amathuba okuba ikristalu izenze i-nucleate. Ku-SiC, ukungcola okuyinhloko kwensimbi kufaka phakathi i-B, i-Al, i-V, ne-Ni, engase yethulwe ngamathuluzi okucubungula ngesikhathi sokucutshungulwa kwe-silicon powder kanye ne-carbon powder. Phakathi kwazo, i-B ne-Al iwukungcola okuyinhloko kokwamukela izinga lamandla angajulile ku-SiC, okuholela ekwehleni kokumelana ne-SiC. Okunye ukungcola kwensimbi kuzokwethula amazinga amaningi wamandla, okuholela ekuzinzeni kwezinto zikagesi zamakristalu e-SiC eyodwa emazingeni okushisa aphezulu, futhi kube nomthelela omkhulu ezindaweni zikagesi ze-high-purity semi-insulating single crystal substrates, ikakhulukazi i-resistivity. Ngakho-ke, i-high-purity silicon carbide powder kumele ihlanganiswe ngangokunokwenzeka.
1.4 Umthelela wokuqukethwe kwe-nitrogen kumpushana ekukhuleni kwekristalu
Izinga lokuqukethwe kwe-nitrogen linquma ukumelana kwe-crystal substrate eyodwa. Abakhiqizi abakhulu badinga ukulungisa ukugxila kwe-nitrogen doping ezintweni zokwenziwa ngokuya ngenqubo yokukhula kwekristalu evuthiwe ngesikhathi sokwenziwa kwempushana. I-high-purity semi-insulating silicon carbide single crystal substrates ayizinto ezithembisayo kakhulu zezingxenye ze-elekthronikhi eziyinhloko. Ukuze kukhule i-high-purity semi-insulating single crystal substrates ene-resistivity ephezulu kanye nezakhiwo zikagesi ezinhle kakhulu, okuqukethwe kwe-nitrogen engcolile eyinhloko ku-substrate kufanele ilawulwe ezingeni eliphansi. I-conductive single crystal substrates idinga okuqukethwe kwe-nitrogen ukuthi kulawulwe ekugxiliseni okuphezulu kakhulu.
2 Ubuchwepheshe bokulawula ukhiye we-powder synthesis
Ngenxa yezindawo ezihlukene zokusetshenziswa kwe-silicon carbide substrates, ubuchwepheshe bokuhlanganiswa kwezimpushana zokukhula bubuye bube nezinqubo ezahlukene. Ku-N-type conductive single crystal growth powders, ukuhlanzeka okuphezulu kokungcola kanye nesigaba esisodwa kuyadingeka; kuyilapho kuma-semi-insulating single crystal powders, ukulawulwa okuqinile kokuqukethwe kwe-nitrogen kuyadingeka.
2.1 Ukulawula usayizi wezinhlayiyana zempushana
2.1.1 Izinga lokushisa le-synthesis
Ukugcina ezinye izimo zenqubo zingashintshile, izimpushana ze-SiC ezikhiqizwe emazingeni okushisa okuhlanganiswa angu-1900 ℃, 2000 ℃, 2100 ℃, kanye no-2200 ℃ athathwa futhi ahlaziywa. Njengoba kuboniswe kuMfanekiso 1, kungabonakala ukuthi usayizi wezinhlayiyana ungama-250 ~ 600 μm ku-1900 ℃, futhi usayizi wezinhlayiyana ukhuphuka ube ngu-600 ~ 850 μm ngo-2000 ℃, futhi usayizi wezinhlayiyana ushintsha kakhulu. Lapho izinga lokushisa liqhubeka nokukhuphuka lifinyelele ku-2100 ℃, ubukhulu bezinhlayiyana ze-SiC powder bungama-850 ~ 2360 μm, futhi ukwanda kuvame ukuba mnene. Usayizi wezinhlayiyana ze-SiC ku-2200 ℃ uzinzile cishe ku-2360 μm. Ukwanda kwezinga lokushisa le-synthesis kusuka ku-1900 ℃ kunomthelela omuhle kusayizi wezinhlayiyana ze-SiC. Lapho izinga lokushisa lokuhlanganiswa liqhubeka nokwenyuka lisuka ku-2100 ℃, usayizi wezinhlayiyana akusashintshi kakhulu. Ngakho-ke, lapho izinga lokushisa le-synthesis lisethelwe ku-2100 ℃, usayizi wezinhlayiyana ezinkulu ungahlanganiswa ekusetshenzisweni kwamandla okuphansi.
2.1.2 Isikhathi sokuhlanganisa
Ezinye izimo zenqubo zihlala zingashintshiwe, futhi isikhathi sokuhlanganisa sisethelwe ku-4 h, 8 h, no-12 h ngokulandelanayo. Ukuhlaziywa kwesampula ye-SiC powder ekhiqiziwe kuboniswa kuMfanekiso 2. Kutholakala ukuthi isikhathi sokuhlanganiswa sinomthelela omkhulu kusayizi wezinhlayiyana ze-SiC. Uma isikhathi sokuhlanganisa singamahora angu-4, usayizi wezinhlayiyana usakazwa ikakhulukazi ku-200 μm; lapho isikhathi sokuhlanganisa singamahora angu-8, usayizi wezinhlayiyana zokwenziwa ukhula kakhulu, ikakhulukazi usatshalaliswa cishe ku-1 000 μm; njengoba isikhathi sokuhlanganisa siqhubeka nokwanda, usayizi wezinhlayiyana uyanda, ikakhulukazi usatshalaliswa cishe ku-2 000 μm.
2.1.3 Umthelela wosayizi wezinhlayiyana zempahla eluhlaza
Njengoba uchungechunge lokukhiqizwa kwe-silicon yasekhaya luthuthukiswa kancane kancane, ukuhlanzeka kwezinto ze-silicon nakho kuyathuthukiswa. Njengamanje, izinto ze-silicon ezisetshenziswa ekuhlanganiseni zihlukaniswe ikakhulukazi i-silicon eyimbudumbudu kanye ne-silicon eyimpuphu, njengoba kukhonjisiwe kuMfanekiso 3.
Kusetshenziswe izinto zokusetshenziswa ezihlukile ze-silicon ukwenza izivivinyo ze-silicon carbide synthesis. Ukuqhathaniswa kwemikhiqizo yokwenziwa kuboniswe ku-Figure 4. Ukuhlaziywa kubonisa ukuthi uma usebenzisa i-block silicon izinto eziluhlaza, inani elikhulu lezakhi ze-Si likhona emkhiqizweni. Ngemva kokuchotshozwa kwe-silicon block okwesibili, isici se-Si emkhiqizweni wokwenziwa sincishiswa kakhulu, kodwa sisekhona. Ekugcineni, i-silicon powder isetshenziselwa ukuhlanganiswa, futhi i-SiC kuphela ekhona emkhiqizweni. Lokhu kungenxa yokuthi enqubweni yokukhiqiza, i-silicon ye-granular yosayizi omkhulu idinga ukusabela kwe-surface synthesis kuqala, futhi i-silicon carbide ihlanganiswa phezulu, okuvimbela i-Si powder yangaphakathi ukuthi iqhubeke nokuhlanganisa ne-C powder. Ngakho-ke, uma i-block silicon isetshenziswa njengempahla eluhlaza, idinga ukuchotshozwa bese ifakwa ngaphansi kwenqubo yesibili yokuhlanganisa ukuthola i-silicon carbide powder yokukhula kwekristalu.
2.2 Ukulawula ifomu lekristalu eliyimpuphu
2.2.1 Umthelela wezinga lokushisa lokuhlanganisa
Ukugcina ezinye izimo zenqubo zingashintshiwe, izinga lokushisa lokuhlanganiswa ngu-1500 ℃, 1700 ℃, 1900 ℃, no-2100 ℃, kanye nempushana ye-SiC ekhiqiziwe ithathwa isampula futhi ihlaziywe. Njengoba kukhonjisiwe kuMfanekiso 5, i-β-SiC inombala ophuzi, futhi i-α-SiC ilula ngombala. Ngokubheka umbala ne-morphology yempushana ehlanganisiwe, kunganqunywa ukuthi umkhiqizo ohlanganisiwe uyi-β-SiC emazingeni okushisa angu-1500℃ no-1700℃. Ngo-1900℃, umbala uba lula, bese kuvela izinhlayiya eziyi-hexagonal, okubonisa ukuthi ngemva kokuba izinga lokushisa likhuphukele ku-1900℃, ukuguquka kwesigaba kwenzeka, futhi ingxenye ye-β-SiC iguqulelwa ku-α-SiC; lapho izinga lokushisa liqhubeka nokukhuphuka lifinyelele ku-2100℃, kutholakala ukuthi izinhlayiya ezihlanganisiwe zisobala, futhi i-α-SiC ngokuyisisekelo ishintshiwe.
2.2.2 Umthelela wesikhathi sokuhlanganisa
Ezinye izimo zenqubo zihlala zingashintshiwe, futhi isikhathi sokuhlanganisa sisethelwe ku-4h, 8h, no-12h, ngokulandelana. I-SiC powder eyenziwe isampula futhi ihlaziywe nge-diffractometer (XRD). Imiphumela iboniswa ku-Figure 6. Isikhathi sokuhlanganiswa sinethonya elithile kumkhiqizo owenziwe yi-SiC powder. Uma isikhathi sokuhlanganisa singu-4 h no-8 h, umkhiqizo wokwenziwa ngokuyinhloko u-6H-SiC; lapho isikhathi sokuhlanganisa siyi-12 h, i-15R-SiC ivela kumkhiqizo.
2.2.3 Umthelela wenani lempahla eluhlaza
Ezinye izinqubo zihlala zingashintshiwe, inani lezinto ze-silicon-carbon liyahlaziywa, futhi izilinganiso zingu-1.00, 1.05, 1.10 kanye no-1.15 ngokulandelana kokuhlolwa kwe-synthesis. Imiphumela ikhonjiswe kuMfanekiso 7.
Kusukela ku-spectrum ye-XRD, kungabonakala ukuthi uma isilinganiso se-silicon-carbon sikhulu kuno-1.05, i-Si eyeqile ivela emkhiqizweni, futhi uma isilinganiso se-silicon-carbon singaphansi kuka-1.05, u-C owedlule uyavela. Lapho isilinganiso se-silicon-carbon ingu-1.05, ikhabhoni yamahhala emkhiqizweni wokwenziwa iyaqedwa, futhi ayikho i-silicon yamahhala evelayo. Ngakho-ke, isilinganiso senani lesilinganiso se-silicon-carbon kufanele sibe ngu-1.05 ukuze kuhlanganiswe i-high-purity SiC.
2.3 Ukulawulwa kokuqukethwe kwe-nitrogen ephansi kumpushana
2.3.1 Izinto zokwenziwa zokwenziwa
Izinto zokusetshenziswa ezisetshenziswe kulokhu kuhlolwa ziyimpushana ye-carbon ehlanzekile kakhulu kanye nempushana ye-silicon ehlanzekile enobubanzi obumaphakathi obungama-20 μm. Ngenxa yobukhulu bezinhlayiyana zabo ezincane nendawo enkulu ethile, kulula ukumunca i-N2 emoyeni. Lapho uhlanganisa impushana, izolethwa efomini lekristalu lempushana. Ukuze kukhule amakristalu ohlobo lwe-N, i-doping engalingani ye-N2 ku-powder iholela ekuphikiseni okungalingani kwe-crystal ngisho nezinguquko kwifomu le-crystal. Okuqukethwe kwe-nitrogen yempushana eyenziwe ngemuva kokwethulwa kwe-hydrogen kuphansi kakhulu. Lokhu kungenxa yokuthi umthamo wama-molecule e-hydrogen mncane. Lapho i-N2 ekhangiswe ku-carbon powder kanye ne-silicon powder ishiswa futhi ibolile isuka phezulu, i-H2 isakazeka ngokugcwele esikhaleni esiphakathi kwezimpushana ngevolumu yayo encane, ithathe indawo ye-N2, futhi i-N2 iphunyuke ku-crucible ngesikhathi senqubo ye-vacuum, ukufeza inhloso yokukhipha okuqukethwe kwe-nitrogen.
2.3.2 Inqubo yokuhlanganisa
Ngesikhathi sokuhlanganiswa kwe-silicon carbide powder, njengoba i-radius ye-athomu ye-carbon nama-athomu e-nitrogen iyafana, i-nitrogen izothatha indawo yezikhala ze-carbon ku-silicon carbide, ngaleyo ndlela ikhulise okuqukethwe kwe-nitrogen. Le nqubo yokuhlola isebenzisa indlela yokwethula i-H2, futhi i-H2 isabela nezinto zekhabhoni ne-silicon ku-synthesis crucible ukukhiqiza amagesi e-C2H2, C2H, kanye ne-SiH. Okuqukethwe kwe-carbon element kuyanda ngokudluliswa kwesigaba segesi, ngaleyo ndlela kunciphisa izikhala zekhabhoni. Inhloso yokukhipha i-nitrogen iyafezwa.
2.3.3 Ukulawulwa kokuqukethwe kwe-nitrogen okungemuva kwenqubo
I-graphite crucibles ene-porosity enkulu ingasetshenziswa njengemithombo eyengeziwe ye-C ukuze imunce umhwamuko we-Si ezingxenyeni zesigaba segesi, inciphise i-Si ezingxenyeni zesigaba segesi, futhi ngaleyo ndlela ikhulise i-C/Si. Ngasikhathi sinye, ama-graphite crucibles nawo angasabela nge-Si atmosphere ukuze akhiqize i-Si2C, i-SiC2 ne-SiC, elingana nomoya we-Si oletha umthombo we-C osuka ku-graphite crucible ungene emkhathini wokukhula, okwandisa isilinganiso se-C, futhi andise isilinganiso se-carbon-silicon. . Ngakho-ke, isilinganiso se-carbon-silicon singandiswa ngokusebenzisa ama-graphite crucibles ane-porosity enkulu, ukunciphisa izikhala ze-carbon, nokufeza injongo yokukhipha i-nitrogen.
3 Ukuhlaziywa nokuklanywa kwenqubo eyodwa ye-crystal powder synthesis
3.1 Umgomo kanye nomklamo wenqubo yokuhlanganisa
Ngocwaningo olunzulu olushiwo ngenhla mayelana nokulawulwa kosayizi wezinhlayiyana, ifomu lekristalu nokuqukethwe kwe-nitrogen ye-powder synthesis, kuhlongozwa inqubo yokuhlanganiswa. I-high-purity C powder kanye ne-Si powder zikhethiwe, futhi zixutshwe ngokulinganayo futhi zilayishwe ku-graphite crucible ngokwesilinganiso se-silicon-carbon ye-1.05. Izinyathelo zenqubo zihlukaniswe ikakhulukazi izigaba ezine:
I-1) Inqubo ye-denitrification ephansi yokushisa, i-vacuuming ku-5 × 10-4 Pa, bese yethula i-hydrogen, yenza ingcindezi yekamelo ibe ngu-80 kPa, igcine imizuzu engu-15, futhi iphinda izikhathi ezine. Le nqubo ingasusa izakhi ze-nitrogen ebusweni be-carbon powder kanye ne-silicon powder.
I-2) Inqubo yokukhishwa kwezinga lokushisa eliphezulu, i-vacuuming ku-5 × 10-4 Pa, bese ifudumeza ku-950 ℃, bese yethula i-hydrogen, yenza ingcindezi yekamelo ibe ngu-80 kPa, igcine imizuzu engu-15, futhi iphinda izikhathi ezine. Le nqubo ingasusa izakhi ze-nitrogen ebusweni be-carbon powder kanye ne-silicon powder, futhi iqhube i-nitrogen endaweni yokushisa.
3) Ukuhlanganiswa kwenqubo yesigaba sokushisa okuphansi, phuma ku-5 × 10-4 Pa, bese ushisa ku-1350 ℃, gcina amahora angu-12, bese wethula i-hydrogen ukuze wenze ukucindezela kwegumbi mayelana ne-80 kPa, gcina ihora elingu-1. Le nqubo ingasusa i-nitrogen eguquguqukayo phakathi nenqubo yokuhlanganiswa.
4) Ukuhlanganiswa kwenqubo yesigaba sokushisa okuphezulu, gcwalisa isilinganiso esithile sokugeleza kwevolumu yegesi yokuhlanzeka okuphezulu kwe-hydrogen ne-argon gas exutshwe, yenza ingcindezi yegumbi ibe ngu-80 kPa, phakamisa izinga lokushisa libe ngu-2100 ℃, gcina amahora angu-10. Le nqubo iqedela ukuguqulwa kwe-silicon carbide powder kusuka ku-β-SiC kuya ku-α-SiC futhi iqedela ukukhula kwezinhlayiya zekristalu.
Okokugcina, linda izinga lokushisa lekamelo liphole liye ekamelweni lokushisa, ugcwalise ukucindezela komkhathi, bese ukhipha impushana.
3.2 Inqubo yempushana ngemva kokucubungula
Ngemuva kokuthi i-powder ihlanganiswe yinqubo engenhla, kufanele isetshenziswe ngemuva kokukhipha ikhabhoni yamahhala, i-silicon nokunye ukungcola kwensimbi futhi ihlole usayizi wezinhlayiyana. Okokuqala, i-powder ehlanganisiwe ifakwa emshinini webhola wokuchotshozwa, futhi i-silicon carbide powder echotshoziwe ifakwa esithandweni somlilo futhi ishiselwe ku-450 ° C nge-oxygen. Ikhabhoni yamahhala ku-powder ikhishwa ukushisa ukuze ikhiqize igesi ye-carbon dioxide ephuma ekamelweni, ngaleyo ndlela ifinyelele ukukhishwa kwekhabhoni yamahhala. Kamuva, uketshezi lokuhlanza olune-acidic luyalungiswa futhi lufakwe emshinini wokuhlanza inhlayiya ye-silicon carbide ukuze kuhlanzwe ukuze kukhishwe ikhabhoni, i-silicon kanye nokungcola okusele kwensimbi okukhiqizwa ngesikhathi senqubo yokuhlanganisa. Ngemuva kwalokho, i-asidi esele igezwa emanzini ahlanzekile futhi yomiswe. Impushana eyomile ihlolwa esikrinini esidlidlizayo ukuze kukhethwe usayizi wezinhlayiyana zokukhula kwekristalu.
Isikhathi sokuthumela: Aug-08-2024