Titanium yeeb nkab fittings raug kub siab tsim ib qho nyuaj, oxygen -nplua nuj txheej txheej paub universally lialpha-cov. Cov kab mob kis no tshwm sim thaum cov pa tawm mus rau hauv cov hlau lattice ntawm qhov kub siab tshaj li ntawm 540℃(1000℃F), stabilizing lub hexagonal ze- ntim alpha theem thiab tsim kom muaj nkig, qis- ductility plhaub. Alpha- rooj plaub tuab tsis tshua muaj ntau tshaj li ob peb feem kaum ntawm ib millimeter nyob rau hauv ib txwm fabrication cycles, tsis tau txawm ib tug ntiav cov pa paug txheej ua raws li ib tug tawg pib qhov chaw nyob rau hauv tensile los yog cyclic load. Ua kom tiav, kev tshem tawm tsis zoo rov ua kom muaj kev ncaj ncees ntawm qhov chaw, tawg toughness, thiab corrosion kuj, thiab tiv thaiv qhov kev ncua sij hawm feem ntau misdiagnosed raws li cov khoom tsis xws luag.
Peb txoj kev tswj hwm alpha- rooj plaub thiab oxide tshem tawm hauv titanium yeeb nkab fabrication:mechanical sib tsoo, acid pickling, thiab tshuaj milling.Txhua txoj hauv kev thov ib qho chaw hauv kev tsim khoom nyob ntawm geometry, batch loj, thiab kev lees paub. Cov lus nug ntawm kev ua tau zoo, txawm li cas los xij, tsis tuaj yeem txo qis rau cov khoom tshem tawm ib leeg. Kev ua tau zoo tiag tiag sib npaug tshem tawm qhov sib xws, qhov ntev ntev, kev xaiv hydrogen - nce kev pheej hmoo, thiab rov ua haujlwm tus nqi ntawm cov khoom siv sab hauv xws li lub luj tshib, reducers, thiab ceg tawm.
mechanical sib tsoo
Kev sib tsoo tshuab siv cov hlua khi, lub log nrov plig plawg, los yog carbide burrs rau lub cev kom tshem tawm cov kab mob. Ntawm cov yeeb nkab ncaj nraim sab nrauv lossis flange ntsej muag, txoj kev no muaj qhov pom tau sai. Cov neeg ua haujlwm tuaj yeem muab cov xim tsis sib xws thiab tshawb xyuas cov kev ua tiav los ntawm kev tshuaj xyuas cov xim dye penetrant. Txawm li cas los xij, titanium tsis tshua muaj thermal conductivity concentrates kev sib txhuam kub hauv qhov sib tsoo. Yog tias qhov ntsuas kub hauv cheeb tsam tshaj li 540℃oxidation pib dua, cov pa oxygen tshiab -enriched txheej tuaj yeem tsim hauv qab cov hlau uas tsis tshua muaj tshwm sim. Tsis tas li ntawd, kev sib tsoo phau ntawv tsis tshua muaj kev tshem tawm cov tuab tuab; residual alpha- cov ntaub ntawv feem ntau nyob hauv qhov sib tw, hauv paus- hla cov ntiv taw, thiab nruj- vojvoog khoov qhov twg lub log tsis tuaj yeem ncav cuag. Rau 3D yeeb nkab haum zoo li lub tee nrog backside gussets, txhua yam kev sib tsoo tsis tuaj yeem lav kev tshem tawm tag nrho. Nws yog kev ua haujlwm - hnyav, geometry- txwv, thiab tuaj yeem embed aluminium oxide lossis silicon carbide fragments rau hauv titanium nto-qhov tshwm sim tsis tau rau cov khoom siv hluav taws xob semiconductor- qib lossis aerospace kua tshuab.
Acid pickling
Acid pickling siv nitric -hydrofluoric acid sib tov, feem ntau 20–40% HNO₃ thiab 1–5% HF, ntawm kev tswj kub ntawm 25℃thiab 50℃. Lub HF dissolves cov oxide thiab qee cov titanium hlau, thaum HNO₃ tiv thaiv kev nqus hydrogen ntau dhau los ntawm kev tuav lub peev xwm oxidizing passivating. Pickling tus nqi tuaj yeem siab tshaj 0.02 hli ib feeb, tshem tawm cov ntaub ntawv alpha{10} thiab cov cua sov ntawm qhov chaw nkag tau sai. Cov txheej txheem kuj tshem tawm tramp hlau thiab lwm yam kab mob smeared. Qhov loj pitfall yog hydrogen uptake. Thaum HNO₃:HF piv qis dhau, lossis da dej kub nce, atomic hydrogen diffuses rau hauv titanium, embrittling lub lattice. Txawm tias lub qhov dej - tswj cov dej da dej tuaj yeem qhia cov hydrogen saum toj no 0.015% huab hwm coj txwv yog tias lub sijhawm immersion ntev. Tom qab-pickling lub tshuab nqus tsev annealing feem ntau yuav tsum tau diffuse hydrogen rov qab tawm, ntxiv ib lub voj voog ua kom sov. Tsis tas li ntawd, acid pickling tawm tsam tag nrho cov hlau tsis sib xws tsuas yog nyob rau hauv kab pom; shadowed nyob rau hauv kab los yog threaded sib txuas tej zaum yuav tshwm sim nyob rau hauv -pickled los yog dimensionally thinned. Kev tswj cov kua qaub pov tseg thiab titanium ion txwv tsis pub ntxiv cov nqi tuav ib puag ncig.
Tshuaj milling
Chemical milling-qee zaum hu ua chem milling lossis tswj cov tshuaj machining- muaj cov txheej txheem sib txawv. Es tsis txhob txhoj puab heev, nws siv cov txheej txheem pastes lossis qis dua - cov kev daws teeb meem siv nrog cov npog ntsej muag meej thiab lub sijhawm tso rau hauv lub sijhawm kom tshem tawm ua ntej - xam cov hlau tuab. Cov txheej txheem no yog tus qauv hauv aerospace titanium siab hlab ntsha thiab cov tawv nqaij airframe qhov twg alpha- tshem tawm qhov tob yuav tsum tau lees paub los ntawm kev saib xyuas daim coupon. Tshuaj milling tshem tawm cov hlau uniformly txawm los ntawm complex geometries thiab dig muag kab noj hniav, muab kev daws teeb meem tuaj yeem ncav cuag lawv. Niaj hnub nimno titanium tshuaj milling cov kev daws teeb meem feem ntau yog nitrate-raws li nrog fluoride ntxiv thiab muaj tswv yim inhibitors uas tsis muaj cov hlau dissolution tus nqi thaum cathodically txwv hydrogen tsim. Tus nqi yog qeeb dua li raw cov kua qaub pickling, feem ntau 0.01-0.03 hli ib teev, tab sis qhov kev tshem tawm yog isotropic thiab dimensionally ruaj khov. Hydrogen absorption yog txo qis los ntawm kev tswj xyuas qhov muaj peev xwm electrochemical hauv cheeb tsam passive; tshaj tawm-milling hydrogen cov ntsiab lus feem ntau tseem qis dua 0.005% yog tias kev tswj cov tshuaj muaj tseeb. Tus nqi tseem ceeb ntawm engineering yog daim ntawv thov daim npog ntsej muag thiab tshem tawm, ntxiv rau kev tshuaj xyuas kev kho cov tshuaj da dej. Rau qhov tseem ceeb titanium yeeb nkab fittings nrog me me - tho sab hauv radii, tshuaj milling yog tib txoj kev uas tuaj yeem ntseeg tau 100% ntawm alpha- rooj plaub yam tsis muaj kev cuam tshuam cov phab ntsa nyias los yog tawm hauv qhov qaug zog -nrawm qhov profile.
Sib piv kev ua tau zoo nruj me ntsis raws sij hawm- ntawm- ib feem nyiam cov kua qaub pickling. Ib lub da dej pickling strips dav dav alpha- rooj plaub los ntawm lub luj tshib hauv 15-30 feeb, thaum chemical milling yuav xav tau ntau teev. Tab sis thaum muaj txiaj ntsig zoo suav nrog tus nqi seem, rov ua dua tshiab, ntxiv lub tshuab nqus tsev degassing, thiab ntev - kev cia siab rau kev pabcuam, tshuaj milling tsis tu ncua. Mechanical sib tsoo qib qis tshaj plaws rau txhua qhov haum uas muaj cov contours sab hauv lossis xav tau cov txheej txheem traceable. Nws tseem muaj txiaj ntsig zoo rau kev kho kom zoo nkauj ntawm cov khoom loj, cov khoom yooj yim tom qab uas cov ntaub ntawv tuab tuab los ntawm ultrasonic gaging tuaj yeem tshem tawm cov kab mob sib kis.
Cov txheej txheem xaiv nyob ntawm tus qauv txais. AMS 2700, ISO 8080, thiab ASTM B600 txhua tus muab kev taw qhia ntawm titanium tshuaj tshem tawm thiab passivation. Kev ua haujlwm tau zoo txhais tau hais tias dhau / ua tsis tiav tsis yog los ntawm kev ploj ntawm cov xim tsis muaj xim tab sis los ntawm kev lees paub tias cov alpha brittle - cov ntaub ntawv txheej yog hloov los ntawm cov suab hlau nrog tsawg dua 200 ppm incremental hydrogen nce. Rau cov ntawv thov uas xav tau tag nrho alpha- rooj plaub tshem tawm ntawm txhua qhov chaw- siab - lub voj voog qaug zog aerospace kab, subsea actuators, lossis kev kho mob isotope hloov kav dej - tshuaj milling sawv ua qhov kev ntseeg siab tshaj plaws, tshawb xyuas tau, thiab cov khoom siv - kev xaiv nyab xeeb. Kev tshuaj xyuas ntawm chav da dej, qhov kub thiab txias, thiab kev tshuaj ntsuam xyuas yuav tsum nyob twj ywm hauv kev tswj xyuas cov txheej txheem nruj, thiab tom qab -milling humidity- lub voj voog ci yog pom zoo kom tsav tawm cov adsorbed hydrogen. Nyob rau hauv cov xwm txheej no, chemical milling muab cov txheej txheem zoo tshaj plaws ntawm tag nrho cov txheej txheem: cov txheej txheem saum npoo zoo, nruj hydrogen tswj, thiab xoom xav tau rau kev kho cov khoom siv kho tshuab tom ntej.
