(1) Izici ze-brazing izinkinga ezihilelekile ku-graphite ne-diamond polycrystalline brazing zifana kakhulu nalezo okuhlangatshezwana nazo ekubrazini kobumba.Uma kuqhathaniswa nensimbi, i-solder inzima ukumanzisa i-graphite ne-diamond polycrystalline materials, futhi i-coefficient yayo yokwandisa okushisayo ihluke kakhulu kuleyo yezinto ezijwayelekile zesakhiwo.Okubili kushiselwa ngokuqondile emoyeni, futhi i-oxidation noma i-carbonization izokwenzeka lapho izinga lokushisa lidlula ama-400 ℃.Ngakho-ke, i-vacuum brazing izokwamukelwa, futhi idigri ye-vacuum akufanele ibe ngaphansi kuka-10-1pa.Ngenxa yokuthi amandla kokubili awaphezulu, uma kukhona ukucindezeleka okushisayo ngesikhathi sokubhoboza, ukuqhekeka kungase kwenzeke.Zama ukukhetha i-brazing filler metal ene-coefficient ephansi yokwanda okushisayo futhi ulawule ngokuqinile izinga lokupholisa.Njengoba ingaphezulu lezinto ezinjalo akulula ukumanziswa yizinsimbi ezijwayelekile zokugcwalisa i-brazing, ungqimba luka-2.5 ~ 12.5um obukhulu W, i-Mo nezinye izakhi zingafakwa ebusweni bezinto ze-graphite ne-diamond polycrystalline ngokuguqulwa kwendawo (i-vacuum coating , i-ion sputtering, isifutho se-plasma nezinye izindlela) ngaphambi kokubhuqa bese wenza ama-carbide ahambisanayo nawo, noma kungasetshenziswa izinsimbi zokugcwalisa i-brazing high.
I-graphite nedayimane zinamabanga amaningi, ahluka ngosayizi wezinhlayiyana, ukuminyana, ubumsulwa nezinye izici, futhi anezici ezihlukene zokubhula.Ngaphezu kwalokho, uma izinga lokushisa lezinto zedayimane le-polycrystalline lidlula i-1000 ℃, isilinganiso sokugqoka se-polycrystalline siqala ukwehla, futhi isilinganiso sokugqoka sincipha ngaphezu kuka-50% lapho izinga lokushisa lidlula i-1200 ℃.Ngakho-ke, lapho i-vacuum brazing idayimane, izinga lokushisa lokubeka kufanele lilawulwe ngaphansi kuka-1200 ℃, futhi i-vacuum degree akufanele ibe ngaphansi kuka-5 × 10-2Pa.
(2) Ukukhethwa kwensimbi yokugcwalisa i-brazing kusekelwe ikakhulukazi ekusetshenzisweni nasekusetshenzisweni kwendawo.Uma isetshenziswa njengento ekwazi ukumelana nokushisa, insimbi yokugcwalisa i-brazing enezinga lokushisa eliphezulu lokubhoboza kanye nokumelana nokushisa okuhle kuzokhethwa;Okwezinto zamakhemikhali ezimelana nokugqwala, kukhethwa izinsimbi zokugcwalisa ezinezinga lokushisa eliphansi lokubhula kanye nokumelana nokugqwala okuhle.Ukuze uthole i-graphite ngemuva kokwelashwa kwe-metallization, i-solder yethusi ehlanzekile ene-ductility ephezulu kanye nokumelana nokugqwala okuhle kungasetshenziswa.I-solder esebenzayo esekelwe esiliva nesekelwe ethusi inokumanzisa okuhle kanye ne-fluidity ku-graphite nedayimane, kodwa izinga lokushisa lesevisi yejoyinti elibrazed kunzima ukudlula ku-400 ℃.Ezingxenyeni ze-graphite namathuluzi edayimane asetshenziswa phakathi kuka-400 ℃ no-800 ℃, isisekelo segolide, isisekelo se-palladium, isisekelo se-manganese noma izinsimbi zokugcwalisa isisekelo se-titanium zivame ukusetshenziswa.Emajoyintini asetshenziswa phakathi kuka-800 ℃ no-1000 ℃, kuzosetshenziswa izinsimbi zokugcwalisa ezisekelwe ku-nickel noma zokubhoboza.Lapho kusetshenziswa izingxenye zegraphite ezingaphezu kuka-1000 ℃, izinsimbi zokugcwalisa zensimbi ezihlanzekile (Ni, PD, Ti) noma izinsimbi zokugcwalisa ingxubevange eziqukethe i-molybdenum, i-Mo, i-Ta nezinye izakhi ezingakha ama-carbides ngekhabhoni zingasetshenziswa.
Ngegraphite noma idayimane ngaphandle kokwelashwa okungaphezulu, izinsimbi zokugcwalisa ezisebenzayo etafuleni 16 zingasetshenziselwa ukubhula okuqondile.Iningi lalezi zinsimbi zokugcwalisa ziyi-titanium esekelwe kanambambili noma ama-ternary alloys.I-titanium ehlanzekile isabela ngokuqinile nge-graphite, engakha ungqimba oluqinile lwe-carbide, futhi i-coefficient yayo yokwandisa eqondile ihluke kakhulu ku-graphite, okulula ukukhiqiza imifantu, ngakho ayikwazi ukusetshenziswa njenge-solder.Ukwengezwa kwe-Cr ne-Ni ku-Ti kunganciphisa indawo encibilikayo futhi kuthuthukise ukumanzisa ngezitsha zobumba.I-Ti iyingxube ye-ternary, eyakhiwe ikakhulukazi i-Ti Zr, kanye nokwengezwa kwe-TA, Nb nezinye izakhi.Ine-coefficient ephansi yokunwetshwa komugqa, okunganciphisa ukucindezelwa kwe-brazing.I-alloy ye-ternary ikakhulukazi eyakhiwe i-Ti Cu ifanele ukugqanyiswa kwe-graphite nensimbi, futhi okuhlangene kunokumelana nokugqwala okuphezulu.
Ithebula le-16 lensimbi yokugcwalisa i-brazing yokubhula okuqondile kwegraphite nedayimane
(3) Inqubo yokubhula izindlela zokubrasa ze-graphite zingahlukaniswa zibe izigaba ezimbili, enye i-brazing ngemva kokufakwa kwensimbi, kanti enye i-brazing ngaphandle kokwelashwa okungaphezulu.Kungakhathaliseki ukuthi iyiphi indlela esetshenziswayo, ukushisela kuzokwenziwa ngaphambi kokuhlanganiswa, futhi ukungcola okungaphezulu kwezinto ze-graphite kuzosulwa ngotshwala noma i-acetone.Endabeni ye-metalization brazing, ungqimba lwe-Ni, Cu noma ungqimba lwe-Ti, Zr noma i-molybdenum disilicide luzogqitshwa endaweni yegraphite ngokufafazwa kwe-plasma, bese kusetshenziswa insimbi yokugcwalisa esekwe ethusi noma insimbi yokugcwalisa esekwe esiliva ukuze kusetshenziswe ukugqama. .Ukubhula okuqondile nge-solder esebenzayo kuyindlela esetshenziswa kakhulu njengamanje.Ukushisa kwe-brazing kungakhethwa ngokusho kwe-solder ehlinzekwe kuthebula 16. I-solder ingafakwa phakathi kwenhlanganisela ye-brazed noma eduze nomkhawulo owodwa.Uma ubhuka ngensimbi ene-coefficient enkulu yokwanda okushisayo, i-Mo noma i-Ti enogqinsi oluthile ingasetshenziswa njengesendlalelo sebhafa esimaphakathi.Isendlalelo soguquko singakhiqiza ukuguqulwa kwepulasitiki ngesikhathi sokushisa kwe-brazing, sibambe ukucindezeleka okushisayo futhi sigweme ukuqhekeka kwe-graphite.Isibonelo, i-Mo isetshenziswa njengengxenye yenguquko ye-vacuum brazing ye-graphite nezingxenye ze-hastelloyn.I-solder ye-B-pd60ni35cr5 enokumelana okuhle nokugqwala kukasawoti oncibilikisiwe kanye nemisebe isetshenziswa.Izinga lokushisa lokubhula liyi-1260 ℃ futhi izinga lokushisa ligcinwa i-10min.
Idayimane lemvelo lingenziwa ngokuqondile nge-b-ag68.8cu16.7ti4.5, b-ag66cu26ti8 namanye ama-solder asebenzayo.Ukubhula kuzokwenziwa ngaphansi kwe-vacuum noma ukuvikelwa kwe-argon ephansi.Izinga lokushisa lokubhula akufanele lidlule ku-850 ℃, futhi izinga lokushisa elisheshayo kufanele likhethwe.Isikhathi sokubamba ekushiseni kwe-brazing akufanele sibe side kakhulu (ngokuvamile cishe ama-10s) ukugwema ukwakheka kongqimba lwe-tic oluqhubekayo kusixhumi esibonakalayo.Lapho i-brazing idayimane nensimbi ye-alloy, i-plastic interlayer noma isendlalelo se-alloy esinwebekayo esiphansi kufanele singezwe ukuze kuguqulwe ukuvimbela ukulimala kwezinhlamvu zedayimane okubangelwa ukucindezeleka okushisayo okudlulele.Ithuluzi elijikayo noma ithuluzi eliyisicefe le-ultra precision machining lenziwa ngenqubo yokubhula, ebeka i-20 ~ 100mg inhlayiya encane yedayimane emzimbeni wensimbi, futhi amandla ahlangene wokuhlanganisa afinyelela ku-200 ~ 250mpa.
Idayimane le-Polycrystalline lingashiswa ilangabi, imvamisa ephezulu noma i-vacuum.I-high frequency brazing noma i-flame brazing izosetshenziswa ukuze kusetshenziswe insimbi eyindilinga eyindilinga yedayimane yokusika insimbi noma itshe.I-Ag Cu Ti esebenzayo yokugcwalisa insimbi enendawo encibilikayo ephansi izokhethwa.Izinga lokushisa le-brazing lizolawulwa ngaphansi kuka-850 ℃, isikhathi sokushisisa akumele sibe side kakhulu, futhi izinga lokupholisa elihamba kancane lizokwamukelwa.Izingcezu zedayimane ze-Polycrystalline ezisetshenziswa ku-petroleum nokumba i-geological zinezimo zokusebenza ezimbi futhi zithwala imithwalo emikhulu.I-nickel based brazing filler metal ingakhethwa futhi ucwecwe lwethusi oluhlanzekile lungasetshenziswa njengesithako sokubopha i-vacuum.Isibonelo, ama-capsules angu-350 ~ 400 Ф 4.5 ~ 4.5mm columnar polycrystalline idayimane ifakwe ku-perforations yensimbi engu-35CrMo noma engu-40CrNiMo ukuze kwakheke amazinyo okusika.I-vacuum brazing yamukelwa, futhi i-vacuum degree ayikho ngaphansi kwe-5 × 10-2Pa, izinga lokushisa lokubhoboza liyi-1020 ± 5 ℃, isikhathi sokubamba ngu-20 ± 2min, futhi amandla okugunda we-brazing joint makhulu kuno-200mpa.
Ngesikhathi sokushisa, isisindo sokuzimela se-weldment sizosetshenziselwa ukuhlanganisa nokubeka ngangokunokwenzeka ukwenza ingxenye yensimbi icindezele i-graphite noma i-polycrystalline impahla engxenyeni engenhla.Uma usebenzisa i-fixture ukuze umise, okokusebenza kuzoba into ene-coefficient yokunweba okushisayo efana naleyo yokushisela.
Isikhathi sokuthumela: Jun-13-2022