Kupaka utoto mu uvuni wa vacuum ndi njira yatsopano yopangira utoto popanda kusuntha pansi pa vacuum. Chifukwa chakuti kupaka utoto kumakhala pamalo opanda vacuum, zotsatira zoyipa za mpweya pa workpiece zimatha kuchotsedwa bwino, kotero kupaka utoto kumatha kuchitika bwino popanda kugwiritsa ntchito flux. Imagwiritsidwa ntchito makamaka pa zitsulo zopaka utoto ndi zinthu zina zomwe zimakhala zovuta kupangira utoto, monga aluminiyamu, titaniyamu, superalloy, refractory alloy ndi ceramics. Cholumikizira chopaka utoto chimakhala chowala komanso chokhuthala, chokhala ndi mphamvu zabwino zamakaniko komanso chokana dzimbiri. Zipangizo zopaka utoto nthawi zambiri sizigwiritsidwa ntchito popangira singano zachitsulo cha kaboni ndi chitsulo chotsika.
Zipangizo zoyatsira moto mu uvuni wa vacuum zimapangidwa makamaka ndi uvuni wa vacuum brazing ndi makina oyeretsera mpweya. Pali mitundu iwiri ya uvuni wa vacuum brazing: Malo otentha a moto ndi malo ozizira a moto. Mitundu iwiri ya uvuni imatha kutenthedwa ndi gasi wachilengedwe kapena magetsi. Itha kupangidwa kukhala ng'anjo yoyikidwa mbali, ng'anjo yoyikidwa pansi kapena ng'anjo yoyikidwa pamwamba (mtundu wa Kang), ndipo makina oyeretsera mpweya akhoza kukhala achilengedwe.
Dongosolo la vacuum limaphatikizapo makamaka vacuum unit, vacuum payipi, vacuum valavu, ndi zina zotero. Vacuum unit nthawi zambiri imapangidwa ndi rotary vane mechanical pump ndi oil diffusion pump. Pampu ya makina yogwiritsidwa ntchito kamodzi imatha kupeza zosakwana 1.35 × Vacuum digiri ya 10-1pa. Kuti mupeze vacuum yambiri, pompo ya mafuta iyenera kugwiritsidwa ntchito nthawi yomweyo, yomwe imatha kufika 1.35 panthawiyi × Vacuum digiri ya 10-4Pa. Kuthamanga kwa mpweya mu dongosolo kumayesedwa ndi vacuum gauge.
Kuphimba mu uvuni wa vacuum ndi kuphimba mu uvuni kapena chipinda chopangira mpweya chomwe chimachotsedwa mpweya. Ndikoyenera makamaka kuphimba malo olumikizirana akuluakulu komanso opitilira. Ndikoyeneranso kulumikiza zitsulo zapadera, kuphatikizapo titaniyamu, zirconium, niobium, molybdenum ndi tantalum. Komabe, kuphimba mu vacuum kulinso ndi zovuta izi:
① Pansi pa vacuum, chitsulo chimakhala chosavuta kusinthasintha, kotero vacuum brazing siyenera kugwiritsidwa ntchito pa zinthu zofewa zomwe zimagwiritsidwa ntchito powotcherera zitsulo ndi solder. Ngati pakufunika, njira zovuta zofananira ziyenera kutsatiridwa.
② Kuphimba kwa vacuum kumakhudzidwa ndi kuuma kwa pamwamba, ubwino wa msonkhano ndi kulekerera kwa ziwalo zophimba, ndipo kumafunikira kwambiri malo ogwirira ntchito komanso mulingo wamalingaliro wa ogwiritsa ntchito.
③ Zipangizo zotsukira mpweya ndi zovuta, zomwe zimayikidwa kamodzi kokha komanso zimakhala ndi ndalama zambiri zokonzera.
Ndiye, kodi mungagwiritse ntchito bwanji njira yopangira brazing mu uvuni wa vacuum? Mukapanga brazing mu uvuni wa vacuum, ikani weldment ndi welding mu uvuni (kapena mu chidebe cha brazing), tsekani chitseko cha ng'anjo (kapena tsekani chivundikiro cha chidebe cha brazing), ndikuyika vacuum musanatenthe. Yambani kaye pampu yamakina, tembenuzani valavu yoyendetsera vacuum digiri ya 1.35pa, tsekani njira yolunjika pakati pa pampu yamakina ndi ng'anjo ya brazing, pangani payipi yolumikizidwa ndi ng'anjo ya brazing kudzera mu pampu yofalitsa, gwiritsani ntchito mkati mwa nthawi yochepa podalira pampu yamakina ndi pampu yofalitsa, pompani ng'anjo ya brazing kufika pa digiri yofunikira ya vacuum, kenako yambani kutentha kwamagetsi.
Pa nthawi yonse yokwera ndi kutentha, chipangizo choyeretsera mpweya chiyenera kugwira ntchito mosalekeza kuti chisunge mpweya mu ng'anjo, kuchepetsa kutuluka kwa mpweya pamalo osiyanasiyana a makina oyeretsera mpweya ndi ng'anjo yoyeretsera mpweya, kutulutsa mpweya ndi nthunzi ya madzi zomwe zimakhudzidwa ndi khoma la ng'anjo, chogwirira ntchito ndi weldment, komanso kusinthasintha kwa chitsulo ndi oxide, kuti achepetse kutsika kwenikweni kwa mpweya. Pali mitundu iwiri ya choyeretsera mpweya: choyeretsera mpweya chapamwamba ndi choyeretsera mpweya chapakati (choyeretsera mpweya chapakati). Choyeretsera mpweya chapamwamba ndi choyenera kwambiri poyeretsera chitsulo chapansi chomwe oxide yake ndi yovuta kuiwononga (monga nickel base superalloy). Choyeretsera mpweya chapang'ono chimagwiritsidwa ntchito nthawi zina pamene chitsulo chapansi kapena chosungunula chimasinthasintha pansi pa kutentha kwa choyeretsera komanso mikhalidwe ya choyeretsera mpweya chapamwamba.
Ngati pakufunika kusamala kwambiri kuti pakhale kuyera kwambiri, njira yoyeretsera vacuum iyenera kugwiritsidwa ntchito musanagwiritse ntchito hydrogen brazing youma. Mofananamo, kugwiritsa ntchito hydrogen youma kapena njira yoyeretsera mpweya wopanda mpweya musanagwiritse ntchito vacuum cleaner kudzathandiza kupeza zotsatira zabwino pakugwiritsa ntchito hydrogen brazing yochuluka.
Nthawi yotumizira: Meyi-07-2022