Chifukwa chiyani SiC-Coated Graphite Crucibles imatsimikizira kupanga kokhazikika?

Mu mizere yopanga makristalo a SiC, mainjiniya ambiri amayang'ana kwambiri kapangidwe ka malo otentha, ma curve owongolera kutentha, ndi kapangidwe ka ufa. Komabe, kusintha kwa zokolola kukachitika, chomwe chimayambitsa nthawi zambiri chimachokera ku chinthu chomwecho - choyikira. Sichitulutsa kuwala, sichizungulira, ndipo sichimawoneka ngati "gawo lofunikira" pazojambula. Koma ngati gawo lituluka pamwamba, kristalo imapanga malo olakwika, kapena kaboni wambiri utatuluka kuchokera pakona, zolakwika zomwe zimachitika pa boule yonse zimatsimikizira chinthu chimodzi: gawoli silili lothandizira.

Kuwonjezeka kwa kupezeka kwaZitsulo zophikira za graphite zophimbidwa ndi SiCMu uvuni wa semiconductor crystal growth fractures, kufotokozera kwake kuli kosavuta: kutentha, mlengalenga, ndi mphamvu ya mayendedwe a zinthu m'dera la kukula zikukankhira malire a magwiridwe antchito a zinthu. Graphite ndi yabwino kwambiri pankhani ya kukana kutentha, makina ogwirira ntchito, ndi kusamutsa kutentha—koma imabwera ndi khalidwe lake: kusinthasintha, kulola kuti zinthu zilowerere., Kuyanjana kwa mankhwala ndi mitundu ya nthunzi kapena zonyansa, komanso zoopsa zosapeŵeka za ufa ndi kupanga tinthu tating'onoting'ono. Chophimba cha SiC chimagwira ntchito ngati chotchinga cholimba motsutsana ndi ululu uwu.

N'chifukwa Chiyani Mungagwiritse Ntchito SiC Coating pa Graphite Crucibles?

Zifukwa zitatu zazikulu:

1. Kuchepetsa kusinthasintha kwa mpweya ndi reactivity

Graphite imayamba kusungunuka kutentha kwambiri, ngakhale mpweya wopanda mpweya. Mpweya wotulutsidwa umasintha kayendedwe ka nthunzi panthawi ya kukula kwa PVT, kusokoneza kayendedwe kake ka madzi ndikuthandizira mapangidwe a zolakwika kapena kukula kosakhazikika.

2. Chepetsani magwero a kuipitsidwa

Ngakhale graphite yoyera kwambiri yomwe imasindikizidwa pang'onopang'ono imakhala ndi ma pores ang'onoang'ono ndipo imakonda kuyamwa mitundu monga nthunzi, zinthu zina, kapena chinyezi. Izi zimatha kutulutsidwa pambuyo pake kutentha kwambiri, zomwe zimawononga chiyero cha kristalo. Chophimba cha SiC chimatseka ma pores ndikuwonjezera ukhondo wa chilengedwe.

3. Kutalikitsa nthawi ya moyo ndikuletsa kufalikira kwa mbewu

Pambuyo poyendetsa mobwerezabwereza, pamwamba pa graphite pamakhala povuta kuwonongeka: ufa, kusweka, kusweka pang'ono, ndi kutayika kwa zinthu. Izi zimapangitsa kuti tinthu tiwonongeke komanso kuti tipeze zokolola zochepa. Chophimba cha SiC cholimba chingachedwetse kwambiri njira zolepherazi, kusunga umphumphu ndi kudalirika kwa pamwamba.

Kuwongolera Njira Zophikira Kumazindikira Kudalirika Kwambiri

Njira yodziwika bwino yophikira ndi Matenda a mtima (CVD)(Chemical Nthunzi Yochokera ku Chemical) ya polycrystalline SiC. Ndi yokhwima komanso yokhazikika pa kutentha. Komabe, kukhala ndi chophimba sikokwanira—kusiyana kwenikweni kwa magwiridwe antchito amunda kumadalira zinthu zazing'ono monga:

● Kufanana kwa makulidwe a kuvala

Ma geometri ovuta kwambiri—masitepe, mipata, ndi zidutswa—amapanga malo okhala ndi mthunzi kapena otsika kumene makulidwe a chophimbacho angagwere pansi pa zomwe zafotokozedwa. Madera opapatiza awa amakhala oyamba kuwonongeka chifukwa cha kutentha.

Yankho:Wopereka chophimbacho ayenera kukhala ndi njira yolondola yowongolera kayendedwe ka madzi mu 3D komanso makina ozungulira kuti atsimikizire kuti zinthuzo zikufalikira mofanana ngakhale pazigawo zovuta.

● Kuchuluka kwa zokutira ndi kuchotsa pinhole

Ngati magawo a CVD (kuchuluka kwa kutentha, kuchuluka kwa mpweya, nthawi yokhala) sakulamulidwa bwino, mabowo ang'onoang'ono kwambiri amatha kupangika. Izi zimakhala malo oyambira kulephera pamene kaboni ikutuluka ndipo dzimbiri la m'deralo limachitika.

Kuzindikira:Kukhuthala koyambira ndi kuyang'ana maso sikokwanira. Gwiritsani ntchito mayeso otulutsa helium kapena mayeso otsala ochepetsa thupi m'magawo angapo a kutentha kuti mupeze ma porosity obisika.

● Mphamvu yomatira komanso kukana kutentha

SiC ndi graphite zili ndi ma coefficients osiyanasiyana a kukula kwa kutentha. Ngati kupsinjika kotsalira mu chophimba sikuchepetsedwa, kapena kuuma kwa pamwamba/kukonzedwa koyambirira sikukwanira, delamination ikhoza kuchitika panthawi ya kutentha.

Njira zabwino kwambiri:Tsimikizirani kutsuka kwa grit-blast ndi ultrasound musanaphike, ndipo tsimikizirani kupirira kwa kutentha pogwiritsa ntchito ng'anjo yeniyeni.

Njira Zolephera Zofala ndi Zotsatira Zake Za Crystal

Pakupanga, chofufumitsa chikalephera, zotsatira zake nthawi zambiri sizimangokhala ppm yochepa, koma kutayika kwathunthu kwa batch ndi kusokonezeka kwa mphamvu kwa milungu ingapo. Izi si vuto lalikulu lokha—ndi vuto la kukhazikika kwa dongosolo.