Porous graphite

Porous graphite amagwiritsidwa ntchito makamaka mu PVT (thupi nthunzi kutengerapo) pakachitsulo carbide (SiC) single galasi kukula ndondomeko, ndi mfundo yaikulu ya kutentha matenthedwe kumunda dongosolo. Chogulitsacho chimapangidwa ndi graphite yapamwamba kwambiri yopanikizidwa ndi isostatically, yomwe imapanga mawonekedwe a yunifolomu komanso osinthika a porous kudzera m'makina olondola a CNC ndi ukadaulo wowongolera pore, kuwonetsetsa kuti magwiridwe antchito apamwamba kwambiri (2200 ℃). Kapangidwe kake kapadera kamapangitsa kuti kutentha kukhale kofanana komanso kumapangitsa kuti mpweya ukhale wabwino, womwe ndi chitsimikizo chachikulu cha kukula kwa kristalo wa SiC.

Zofunika zazikulu ndi ubwino wa ndondomeko:

Kuyera kwambiri komanso chilema chochepa

Njira yoyeretsera kutentha kwambiri (3000 ℃ mankhwala) imagwiritsidwa ntchito kupititsa patsogolo zonyansa zopanda zitsulo monga mpweya ndi nayitrogeni. Chotsani kuwonongeka kwa makristalo odetsedwa (monga ma microtubules, dislocations) kuti muwonetsetse kuti magetsi a SiC single crystals akugwira ntchito mofanana.

Kukhazikika kwapamwamba kwambiri kwa kutentha ndi kuwongolera kumunda kwamafuta

M'malo a argon / vacuum, imatha kupirira 2200 ℃ mosalekeza kwa maola opitilira 1000, kutsika kocheperako pakukulitsa kwamafuta, ndikupewa kusweka kwazinthu chifukwa cha kupsinjika kwamafuta.

The porosity amathandiza gradient kugawa kapangidwe, kuphatikiza CFD kayeseleledwe kukhathamiritsa kukula pore (10-200μm), molondola kugawa munda matenthedwe kugawa, kuchepetsa kutentha gradient kusinthasintha (mkati ± 3 ℃), ndi kusintha galasi kukula mofanana.

Zothetsera makonda

Kusintha kwa geometric: Kuthandizira kukonza mawonekedwe ovuta (monga annular crucible, chishango chamitundu yambiri), kufananiza mawonekedwe ang'anjo yamakasitomala.

Chithandizo chapamwamba: Perekani ntchito zopukutira bwino kwambiri kapena zokutira kuti musachite dzimbiri komanso moyo wautumiki.

Kutsimikizira magwiridwe antchito

Mu PVT SiC crystallization ndondomeko, monga crucible ndi matenthedwe gawo gawo:

Kuchulukitsa kukula kwa kristalo ndi 15% -20% (poyerekeza ndi graphite yachikhalidwe);

Zokolola za Wafer zawonjezeka kufika pa 90% (4 inch SiC single crystal);

Nthawi yokonza zidayo imakulitsidwa mpaka miyezi 6 (miyezi itatu yokhazikika).

Tsatanetsatane wazomwe:

1. Mayina ena: PVT graphite crucible, silicon carbide kukula ndi porous graphite.

2. Ntchito: PVT njira (thupi gasi zoyendera njira) SiC single galasi kukula pachimake matenthedwe gawo gawo.

3. Magawo apakati: chiyero ≥99.9995%, porosity 15-30%, kukana kutentha kwa 2200 ℃ (malo a mpweya wa inert), matenthedwe matenthedwe 100-150 W / m·K.

PVT kukula ng'anjo msonkhano: Monga gawo la SiC zinthu sublimation ndi crystal kukula, amapereka khola matenthedwe munda kugawa.

Chigawo chachitetezo cham'munda chotenthetsera: mawonekedwe a porous amachepetsa kupsinjika kwamafuta ndikutalikitsa moyo wautumiki wa zida.

Chingwe cha kristalo cha mbewu: mphamvu zamakina apamwamba kuti zithandizire kristalo wa mbewu, kuwonetsetsa kuti kristaloyo ikukula molunjika.

Wosanjikiza wa gasi: kukhathamiritsa kusamutsa kwa gasi, sinthani mtundu wa kristalo umodzi ndi kukula kwake.

Kutentha kwapamwamba kwambiri: palibe kusintha kofewetsa pa 2200 ℃, kumathandizira maola opitilira 1000 akugwira ntchito mosalekeza.

Kapangidwe kamalo otentha: Kuphatikizika ndi kayeseleledwe ka CFD kukhathamiritsa pore gradient, kusintha mawonekedwe a kristalo ndi zokolola.

Ntchito yobwerezabwereza mwachangu: perekani mayeso ofananira ndi magawo ndikupereka yankho lachitsanzo mkati mwa maola 72.