Tsarin asali naSiCGirman kristal ya kasu kashi biyu: sublimation da rugujewar albarkatun ƙasa a babban zafin jiki, jigilar abubuwan da ke cikin lokacin iskar gas a ƙarƙashin tasirin canjin zafin jiki, da kuma sake haɓaka abubuwan da ke cikin lokacin iskar gas a cikin kristal iri. Dangane da wannan, an raba cikin bututun zuwa sassa uku: yankin kayan abu, ɗakin girma da kristal iri. An zana samfurin kwaikwayo na lambobi bisa ga ainihin juriyaSiCKayan aikin girma na lu'ulu'u guda ɗaya (duba Hoto na 1). A cikin lissafin: ƙasanmai kama da wutaTana da nisan mm 90 daga ƙasan na'urar dumama gefe, zafin saman na'urar dumama shine 2100 ℃, diamita na barbashi na kayan shine 1000 μm, porosity shine 0.6, matsin girma shine 300 Pa, kuma lokacin girma shine awanni 100. Kauri na PG shine 5 mm, diamita yayi daidai da diamita na ciki na na'urar dumama, kuma yana da nisan mm 30 sama da kayan. Ana la'akari da hanyoyin sublimation, carbonization, da sake sake fasalin yankin kayan masarufi a cikin lissafin, kuma ba a la'akari da amsawar tsakanin PG da abubuwan da ke cikin yanayin iskar gas ba. An nuna sigogin halayen zahiri da suka shafi lissafi a cikin Jadawali na 1.
Siffa ta 1 Tsarin lissafin kwaikwayo. (a) Tsarin filin zafi don kwaikwayon girma na lu'ulu'u; (b) Raba yankin ciki na bututun ruwa da matsalolin jiki masu alaƙa
Tebur 1 Wasu sigogi na zahiri da aka yi amfani da su a cikin lissafin
Siffa ta 2(a) ta nuna cewa zafin tsarin da ke ɗauke da PG (wanda aka nuna a matsayin tsari na 1) ya fi na tsarin da ba shi da PG (wanda aka nuna a matsayin tsari na 0) a ƙasa da PG, kuma ya fi na tsarin 0 a sama da PG. Matsakaicin yanayin zafi yana ƙaruwa, kuma PG yana aiki a matsayin wakili mai hana zafi. A cewar Sifofi na 2(b) da 2(c), yanayin zafin jiki na axial da radial na tsari na 1 a yankin kayan abu ya ƙanƙanta, rarrabawar zafin ya fi daidaito, kuma sublimation na kayan ya fi cikakke. Ba kamar yankin kayan abu ba, Siffa ta 2(c) ta nuna cewa yanayin zafin jiki na radial a cikin nau'in lu'ulu'u na tsari na 1 ya fi girma, wanda ƙila zai iya faruwa ta hanyar bambancin rabo na yanayin canja wurin zafi daban-daban, wanda ke taimaka wa lu'ulu'u ya girma tare da hanyar haɗin convex. A cikin Siffa ta 2(d), zafin jiki a wurare daban-daban a cikin bututun yana nuna ƙaruwa yayin da girma ke ci gaba, amma bambancin zafin jiki tsakanin tsari na 0 da tsari na 1 yana raguwa a hankali a yankin kayan abu kuma yana ƙaruwa a hankali a cikin ɗakin girma.
Hoto na 2 Rarraba zafin jiki da canje-canje a cikin bututun. (a) Rarraba zafin jiki a cikin bututun tsari 0 (hagu) da tsari 1 (dama) a 0 h, naúrar: ℃; (b) Rarraba zafin jiki a layin tsakiya na bututun tsari 0 da tsari 1 daga ƙasan kayan zuwa kristal iri a 0 h; (c) Rarraba zafin jiki daga tsakiya zuwa gefen bututun akan saman kristal iri (A) da saman kayan (B), tsakiya (C) da ƙasa (D) a 0 h, axis na kwance r shine radius na kristal iri don A, da radius na yankin kayan don B~D; (d) Canjin zafin jiki a tsakiyar ɓangaren sama (A), saman kayan (B) da tsakiya (C) na ɗakin girma na tsari 0 da tsari 1 a 0, 30, 60, da 100 h.
Siffa ta 3 tana nuna jigilar kayan a lokuta daban-daban a cikin bututun ƙarfe na tsari 0 da tsari 1. Yawan kwararar kayan iskar gas a yankin kayan ƙarfe da ɗakin girma yana ƙaruwa tare da ƙaruwar matsayi, kuma jigilar kayan yana raguwa yayin da girma ke ci gaba. Siffa ta 3 kuma ta nuna cewa a ƙarƙashin yanayin kwaikwayo, kayan ƙarfe da farko suna yin zane a bangon gefe na bututun ƙarfe sannan a ƙasan bututun ƙarfe. Bugu da ƙari, akwai sake yin amfani da su a saman kayan ƙarfe kuma yana kauri a hankali yayin da girma ke ci gaba. Sifofi na 4(a) da 4(b) sun nuna cewa ƙimar kwararar kayan da ke cikin kayan ƙarfe yana raguwa yayin da girma ke ci gaba, kuma ƙimar kwararar kayan a cikin awanni 100 kusan kashi 50% na lokacin farko ne; duk da haka, ƙimar kwararar tana da girma sosai a gefen saboda graphitization na kayan, kuma ƙimar kwararar da ke gefen ta fi sau 10 na ƙimar kwararar a yankin tsakiya a awanni 100; Bugu da ƙari, tasirin PG a cikin tsari na 1 yana sa ƙimar kwararar abu a yankin kayan abu na tsari na 1 ya yi ƙasa da na tsari na 0. A cikin Hoto na 4(c), kwararar abu a yankin kayan abu da ɗakin girma yana raguwa a hankali yayin da girma ke ci gaba, kuma kwararar abu a yankin kayan abu na ci gaba da raguwa, wanda ke faruwa ne sakamakon buɗewar tashar kwararar iska a gefen bututun ruwa da toshewar sake kunnawa a saman; a cikin ɗakin girma, ƙimar kwararar abu na tsari na 0 yana raguwa da sauri a cikin awanni 30 na farko zuwa 16%, kuma yana raguwa da 3% kawai a lokacin da ke biyo baya, yayin da tsari na 1 ya kasance mai daidaito a duk tsawon tsarin girma. Saboda haka, PG yana taimakawa wajen daidaita ƙimar kwararar abu a cikin ɗakin girma. Hoto na 4(d) ya kwatanta ƙimar kwararar abu a gaban girma na lu'ulu'u. A farkon lokacin da kuma awanni 100, jigilar kayan da ke cikin yankin girma na tsari 0 ya fi ƙarfi fiye da na tsari 1, amma koyaushe akwai yankin kwarara mai yawa a gefen tsari 0, wanda ke haifar da girma mai yawa a gefen. Kasancewar PG a cikin tsari 1 yana danne wannan lamari yadda ya kamata.
Hoto na 3 Gudun abu a cikin bututun. Layukan kwarara (hagu) da vectors na gudu (dama) na jigilar kayan iskar gas a cikin tsari 0 da 1 a lokuta daban-daban, sashin vector na gudu: m/s
Hoto na 4 Canje-canje a cikin ƙimar kwararar abu. (a) Canje-canje a cikin rarrabawar ƙimar kwararar abu a tsakiyar kayan albarkatun gini na 0 a 0, 30, 60, da 100 h, r shine radius na yankin kayan albarkatun; (b) Canje-canje a cikin rarrabawar ƙimar kwararar abu a tsakiyar kayan albarkatun gini na 1 a 0, 30, 60, da 100 h, r shine radius na yankin kayan albarkatun; (c) Canje-canje a cikin ƙimar kwararar abu a cikin ɗakin girma (A, B) da cikin kayan albarkatun (C, D) na tsarin 0 da 1 akan lokaci; (d) Rarraba ƙimar kwararar abu kusa da saman lu'ulu'u na tsarin 0 da 1 a 0 da 100 h, r shine radius na lu'ulu'u na iri
C/Si yana shafar daidaiton kristal da kuma yawan lahani na girmar kristal na SiC. Hoto na 5(a) yana kwatanta rarraba rabon C/Si na tsarin guda biyu a farkon lokacin. Rabon C/Si a hankali yana raguwa daga ƙasa zuwa saman bututun, kuma rabon C/Si na tsari na 1 koyaushe yana fi na tsari na 0 a wurare daban-daban. Hotuna na 5(b) da 5(c) sun nuna cewa rabon C/Si yana ƙaruwa a hankali tare da girma, wanda ke da alaƙa da ƙaruwar zafin jiki na ciki a matakin ƙarshe na girma, haɓaka graphitization na kayan abu, da kuma amsawar abubuwan Si a cikin matakin iskar gas tare da bututun graphite. A cikin Hoto na 5(d), rabon C/Si na tsari na 0 da tsari na 1 sun bambanta sosai a ƙasa da PG (0, 25 mm), amma ɗan bambanta sama da PG (50 mm), kuma bambancin yana ƙaruwa a hankali yayin da yake kusantar kristal. Gabaɗaya, rabon C/Si na tsari na 1 ya fi girma, wanda ke taimakawa wajen daidaita siffar kristal da rage yuwuwar canjin lokaci.
Hoto na 5 Rarrabawa da canje-canjen rabon C/Si. (a) Rarraba rabon C/Si a cikin ramukan tsari 0 (hagu) da tsari 1 (dama) a awanni 0; (b) Rarraba C/Si a wurare daban-daban daga layin tsakiya na bututun tsari 0 a lokuta daban-daban (awanni 0, 30, 60, 100); (c) Rarraba C/Si a wurare daban-daban daga layin tsakiya na bututun tsari 1 a lokuta daban-daban (awanni 0, 30, 60, 100); (d) Kwatanta rabon C/Si a wurare daban-daban (awanni 0, 25, 50, 75, 100 mm) daga layin tsakiya na bututun tsari 0 (layi mai ƙarfi) da tsari 1 (layi mai lanƙwasa) a lokuta daban-daban (awanni 0, 30, 60, 100).
Siffa ta 6 ta nuna canje-canje a cikin diamita na barbashi da kuma ramukan da ke cikin sassan kayan amfanin gona na gine-ginen guda biyu. Siffar ta nuna cewa diamita na kayan amfanin gona yana raguwa kuma ramukan da ke cikin ƙasa suna ƙaruwa kusa da bangon da ke kewaye, kuma ramukan da ke gefen suna ci gaba da ƙaruwa kuma diamita na barbashi yana ci gaba da raguwa yayin da girma ke ci gaba. Matsakaicin ramukan da ke gefen yana kusan 0.99 a cikin awanni 100, kuma mafi ƙarancin diamita na barbashi shine kusan 300 μm. Diamita na barbashi yana ƙaruwa kuma ramukan da ke cikin ƙasa suna raguwa a saman saman kayan amfanin gona, wanda ya dace da sake yin amfani da su. Kauri na yankin sake yin amfani da su yana ƙaruwa yayin da girma ke ci gaba, kuma girman barbashi da ramukan da ke cikin ƙasa suna ci gaba da canzawa. Matsakaicin diamita na barbashi ya kai fiye da 1500 μm, kuma mafi ƙarancin ramukan da ke cikin ƙasa shine 0.13. Bugu da ƙari, tunda PG yana ƙara zafin yankin kayan amfanin gona kuma babban iskar gas yana da ƙarami, kauri na sake yin amfani da su na saman ɓangaren kayan amfanin gona na tsari na 1 ƙarami ne, wanda ke inganta ƙimar amfani da kayan amfanin gona.
Hoto na 6 Canje-canje a cikin diamita na barbashi (hagu) da porosity (dama) na yankin kayan abu na tsari 0 da tsari 1 a lokuta daban-daban, naúrar diamita na barbashi: μm
Siffa ta 7 ta nuna cewa tsarin 0 yana raguwa a farkon girma, wanda zai iya danganta da yawan kwararar abu da ke faruwa sakamakon zane-zanen gefen kayan da aka yi amfani da su. Matsayin warping yana raguwa a lokacin tsarin girma na gaba, wanda ya yi daidai da canjin saurin kwararar abu a gaban girman lu'ulu'u na tsari 0 a cikin Siffa ta 4 (d). A cikin tsari na 1, saboda tasirin PG, haɗin lu'ulu'u bai nuna warping ba. Bugu da ƙari, PG kuma yana sa saurin girma na tsari 1 ya yi ƙasa da na tsari 0. Kauri na tsakiya na lu'ulu'u na tsari 1 bayan sa'o'i 100 shine kashi 68% kawai na tsarin 0.
Hoto na 7 Canje-canje a cikin yanayin tsari 0 da tsari 1 lu'ulu'u a awanni 30, 60, da 100
An gudanar da girman kristal a ƙarƙashin yanayin aikin kwaikwayon lambobi. An nuna lu'ulu'u da aka haɓaka ta hanyar tsari 0 da tsari 1 a cikin Hoto na 8(a) da Hoto na 8(b), bi da bi. Lu'ulu'u na tsari 0 yana nuna haɗin gwiwa mai lanƙwasa, tare da ɗumamar yanayi a yankin tsakiya da kuma canjin yanayi a gefen. Lanƙwasa na saman yana wakiltar wani matakin rashin daidaituwa a cikin jigilar kayan gas-lokaci, kuma faruwar canjin yanayi ya yi daidai da ƙarancin rabon C/Si. Haɗin lu'ulu'u da aka haɓaka ta hanyar tsari 1 yana da ɗan lanƙwasa, ba a sami canjin yanayi ba, kuma kauri shine 65% na lu'ulu'u ba tare da PG ba. Gabaɗaya, sakamakon haɓakar lu'ulu'u ya yi daidai da sakamakon kwaikwayon, tare da babban bambancin zafin jiki na radial a mahaɗin lu'ulu'u na tsari 1, ana danne saurin girma a gefen, kuma jimlar yawan kwararar abu yana da jinkiri. Yanayin gabaɗaya ya yi daidai da sakamakon kwaikwayon lambobi.
Hoto na 8 Lu'ulu'u na SiC da aka haɓaka a ƙarƙashin tsari 0 da tsari 1
Kammalawa
PG yana taimakawa wajen inganta yanayin zafin jiki na yankin albarkatun ƙasa da kuma inganta daidaiton zafin jiki na axial da radial, yana haɓaka cikakken sublimation da amfani da kayan; bambancin zafin jiki na sama da ƙasa yana ƙaruwa, kuma radial gradient na saman kristal iri yana ƙaruwa, wanda ke taimakawa wajen kiyaye haɓakar convex interface. Dangane da canja wurin taro, gabatar da PG yana rage yawan canja wurin taro gabaɗaya, ƙimar kwararar abu a cikin ɗakin girma wanda ke ɗauke da PG yana canzawa kaɗan da lokaci, kuma dukkan tsarin girma ya fi karko. A lokaci guda, PG kuma yana hana faruwar canja wurin taro mai yawa a gefen da ya wuce kima. Bugu da ƙari, PG kuma yana ƙara rabon C/Si na yanayin girma, musamman a gefen gaba na haɗin kristal iri, wanda ke taimakawa wajen rage faruwar canjin lokaci yayin aikin girma. A lokaci guda, tasirin rufin zafi na PG yana rage faruwar sake sake yin amfani da kayan a saman kayan zuwa wani mataki. Don haɓakar kristal, PG yana rage saurin girma na kristal, amma haɗin girma ya fi convex. Saboda haka, PG hanya ce mai inganci don inganta yanayin girma na lu'ulu'u na SiC da kuma inganta ingancin lu'ulu'u.
Lokacin Saƙo: Yuni-18-2024