Kuisa simbi muchoto chevacuum inzira itsva yekubisa simbi pasina kuifambisa kana yaiswa muvacuum. Nekuti kubisa simbi iri munzvimbo isina kupinza simbi, kukuvadza kwemhepo pabasa kunogona kubviswa zvinobudirira, saka kubisa simbi kunogona kuitwa zvinobudirira pasina kuisa flux. Inonyanya kushandiswa pakuisa simbi nesimbi dzakaoma kuifambisa, dzakadai sealuminium alloy, titanium alloy, superalloy, refractory alloy uye ceramics. Nzvimbo yakasungirirwa simbi yakajeka uye yakakora, ine hunhu hwakanaka hwemakanika uye inodzivirira ngura. Midziyo yekubisa simbi yevacuum kazhinji haishandiswi pakushongedza netsanga yesimbi yekabhoni nesimbi isina kupinza simbi.
Midziyo yekubatidza muchoto chevacuum inonyanya kugadzirwa nechoto chevacuum brazing uye system ye vacuum. Kune mhando mbiri dzevacuum brazing Furnaces: Chitofu chinopisa nechitofu chinotonhora. Mhando mbiri dzechoto dzinogona kudziiswa negasi rechisikigo kana kudziisa nemagetsi. Dzinogona kugadzirwa kuva chimiro chechoto chakaiswa padivi, choto chakaiswa pasi kana chigadziko chepamusoro (rudzi rweKang), uye system ye vacuum inogona kuve yepasi rose.
Sisitimu yekubvisa mafuta inosanganisa vacuum unit, vacuum pipeline, vacuum valvu, nezvimwewo. Iyi vacuum unit inowanzo gadzirwa ne rotary vane mechanical pombi uye oil diffusion pombi. Pombi yemuchina inoshandiswa kamwe chete inogona kuwana pasi pe 1.35 × Vacuum degree ye 10-1pa level. Kuti iwane vacuum yakakwira, pombi yekubvisa mafuta inofanira kushandiswa panguva imwe chete, iyo inogona kusvika 1.35 panguva ino × Vacuum degree ye 10-4Pa level. Kumanikidzwa kwegasi musystem kunoyerwa ne vacuum gauge.
Kuisa simbi muchoto chevacuum zvinoreva kuisa simbi muchoto kana mukamuri rekuisa simbi rine mweya wakabviswa. Inonyanya kukodzera kuisa simbi huru uye dzinogara dziripo. Inokodzerawo kubatanidza simbi dzakakosha, dzinosanganisira titanium, zirconium, niobium, molybdenum uye tantalum. Zvisinei, kuisa simbi muchoto chevacuum kunewo matambudziko anotevera:
① Kana simbi yaiswa muchina wevacuum, zviri nyore kupwanyika, saka vacuum brazing haifanirwe kushandiswa pakugadzira simbi yebase ne solder welding zvinhu zvinopfava. Kana zvichidikanwa, matanho akaomarara anoenderana nawo anofanira kutorwa.
② Kushandiswa kwevacuum brazing kunonyatsoenderana nekuoma kwenzvimbo, kunaka kwekubatanidza zvinhu uye kushivirira kukwana kwezvikamu zvakasungirirwa, uye kune zvinodiwa zvakanyanya munzvimbo yekushanda uye nhanho yedzidziso yevashandi.
③ Midziyo yekubvisa tsvina yakaoma, ine mari yakawanda inoshandiswa kamwe chete uye mari yakawanda yekugadzirisa.
Saka, maitiro ekushandisa nzira yekuisa brazing mu vacuum furnace? Kana brazing ichiitwa mu vacuum furnace, isa weldment ne welding mu furnace (kana mu brazing container), vhara gonhi re furnace (kana vhara chifukidziro che brazing container), uye gadzira vacuum cleaner usati wapisa. Tanga pombi ye mechanical kutanga, tendeudza steering valve mushure mekunge vacuum degree yasvika 1.35pa, vhara nzira yakananga pakati pepombi ye mechanical ne brazing furnace, gadzira pombi yakabatana ne brazing furnace kuburikidza ne diffusion pombi, shanda mukati menguva pfupi nekushandisa mechanical pombi ne diffusion pombi, pomba brazing furnace kusvika pa vacuum degree inodiwa, wobva watanga kupisa nemagetsi.
Munguva yese yekukwira nekudziya kwekupisa, vacuum unit inofanira kushanda nguva dzose kuchengetedza dhigirii re vacuum muchoto, kudzivirira kubuda kwemhepo panzvimbo dzakasiyana dze vacuum system ne brazing furnace, kuburitswa kwegasi nemvura inonyungudutswa nemadziro echoto, fixture ne weldment, uye volatilization yesimbi ne oxide, kuitira kuderedza kudonha kwemhepo chaiyo. Kune mhando mbiri dze vacuum brazing: high vacuum brazing uye partial vacuum (medium vacuum). High vacuum brazing yakakodzera kwazvo pabrazing base metal ine oxide yakaoma kuora (senge nickel base superalloy). Partial vacuum brazing inoshandiswa panguva iyo base metal kana solder inoputika pasi pekupisa kwe brazing uye high vacuum conditions.
Kana paine matanho akakosha ekudzivirira kuchena kwakanyanya, nzira yekuchenesa vacuum inofanira kushandiswa usati waisa hydrogen brazing yakaoma. Saizvozvowo, kushandisa nzira yekuchenesa hydrogen yakaoma kana inert gas usati waisa vacuum pumping kunobatsira kuwana mhedzisiro iri nani mukuisa hydrogen yakawanda.
Nguva yekutumira: Chivabvu-07-2022