Tshuaj polishing tseem yog ib txoj kev siv dav dav rau titanium thiab nws cov alloys, muaj nuj nqis rau nws lub peev xwm los tsim cov xim ci ntsa iab, tsis muaj kev sib cuag. Txawm li cas los xij, tsis yog -cov polishing tsis zoo- tshwm sim raws li thaj chaw tshaj - etching, ntws cov cim, cov txiv kab ntxwv tev textures, los yog tsis sib xws gloss hla ib qho chaw ua haujlwm - tseem yog ib qho kev sib tw tsis tu ncua hauv qhov chaw tsim khoom. Rau kev lag luam xws li aerospace fasteners mus rau kev kho mob implants, deg tag uniformity ncaj qha cuam tshuam rau corrosion kuj, qaug zog kev ua tau zoo, thiab post- ua adhesion. Kab lus no tshuaj xyuas cov hauv paus ntsiab lus ntawm kev tsis sib xws hauv titanium tshuaj polishing thiab muab kev ua tau zoo, txheej txheem - qib kev ntsuas.
1. Kev faib tawm tsis zoo thiab kev kuaj pom pom
Ua ntej kho qhov tsis zoo, kev txheeb xyuas qhov tseeb yog qhov tseem ceeb. Tsis yog-cov polishing tsis sib xws ntawm titanium nto feem ntau poob rau hauv ntau pawg sib txawv, txhua qhov taw qhia rau qhov sib txawv hauv paus.
Txiv kab ntxwv tev tshwm sim thaum tus nqi ntawm cov tshuaj tua kab sib txawv ntawm cov theem sib txawv ntawm cov metallurgical los yog grain orientations nyob rau hauv cov hlau. Hauv ob-theem alloys zoo li Ti-6Al-4V (TC4), theem dissolves nyiam nyob rau hauv tej yam acidity, tawm hauv roughened nto topography. Pitting feem ntau qhia txog qhov siab HF ntau dhau los yog HF-rau-HNO₃ piv rau qhov pom qhov rais. Flow marks thiab ntug-center sib txawv yuav luag ib txwm taug qab rov qab rau cov dej dynamics thiab thermal uniformity teeb meem.
2. Tshuaj Chemistry: HF/HNO₃ Ratio raws li Thawj Tswj Hwm Variable
HF-HNO₃-H₂O system tseem ua haujlwm rau titanium tshuaj polishing. HF ua raws li tus neeg sawv cev active dissolving, tawm tsam titanium substrate thiab tshem tawm cov haiv neeg oxide txheej. HNO₃ ua haujlwm ob lub luag haujlwm: oxidizing cov yaj Ti³⁺ rau Ti⁴⁺ kom tiv thaiv kom tsis txhob muaj kab mob, thiab txhawb kev tsim cov yeeb yaj kiab passive uas tswj hwm tag nrho cov etch tus nqi.
Kev lag luam kev coj ua feem ntau tsom rau HF concentrations ntawm 3-5% thiab HNO₃ concentrations ntawm 15-30% los ntawm ntim. Hauv lub qhov rais no, HF-rau-HNO₃ piv yog qhov ntsuas qhov ntsuas tseem ceeb. Cov kev tshawb fawb ntawm TC4 tau tshuaj xyuas qhov sib piv ntawm 1: 4, 1: 6, thiab 1: 8 (HF: HNO₃ los ntawm ntim). Ib qho piv txwv uas yog HF dhau lawm- nplua nuj ua rau muaj kev txhoj puab heev, tswj tsis tau etching nrog pitting thiab tsis yog{17}}cov khoom siv tsis zoo. Ib qho piv txwv uas yog HNO₃- nplua nuj ua rau qeeb cov tshuaj tiv thaiv ntau dhau thiab tuaj yeem ua rau muaj kev cuam tshuam ua ntej qib tiav, ua rau muaj huab lossis tsis sib xws.
Lub hauv paus txheej txheem muaj feem xyuam rau kev nthuav dav -tswj tiv thaiv kev ua kom ua haujlwm - tswj etching. Thaum HF concentration zoo sib npaug nrog HNO₃, qhov kev sib cais yog txwv los ntawm kev thauj cov reactants rau saum npoo es tsis yog los ntawm cov tshuaj tiv thaiv saum npoo nws tus kheej. Qhov kev nthuav dav no - txwv tsis pub dhau ib txwm ua rau kev tshem tawm cov khoom sib xws thoob plaws macro- nplai topography, raws li cov yam ntxwv protruding tau txais me ntsis diffusion flux ntau dua li qhov chaw recessed - cov nyhuv leveling uas txhais tau tias muaj tseeb polishing.
3. Kev Tswj Kub thiab Kev Tswj Thermal Gradient
Kub exerts ib tug pronounced nyhuv ntawm titanium tshuaj polishing kinetics. Cov tshuaj tiv thaiv nce los ntawm kwv yees li 1.5-2 × rau txhua txhua 5℃nce hauv cov tshuaj kub. Qhov kub gradient me me li 3-4℃thoob plaws hauv da dej tuaj yeem tsim pom qhov sib txawv ntawm qhov sib txawv ntawm cov khoom ua haujlwm nyob rau ntawm qhov chaw sib txawv, lossis txawm nyob nruab nrab ntawm sab saum toj thiab hauv qab ntawm ib qho loj.
Kev pom zoo ua haujlwm ntau rau feem ntau titanium tshuaj polishing formulations yog 20-35 degree. Txawm li cas los xij, qhov ntau yam no dav dhau rau kev ua haujlwm precision. Kev tswj nruj dua li ± 1.5℃yog qhov tsim nyog rau cov txiaj ntsig zoo ib yam. Kub excursions saum 35℃nrawm HF volatilization, uas hloov cov tshuaj chemistry hauv zos ze cov kua- huab cua interface. Qhov tshwm sim no ua rau muaj tus yam ntxwv tsis xws luag: dhau- polished sab sauv ntawm cov vertically immersed qhov chaw thiab nyob rau hauv - polished seem, nrog ib tug maj mam hloov chaw nyob rau hauv nruab nrab.
Cov tswv yim tiv thaiv muaj xws li cov tsho tso tsheb hlau luam nrog cov dej tswj qhov kub thiab txias, cov cua sov tso rau hauv qhov sib faib ua ke -ib qho -derivative (PID) controllers, thiab da dej tas li recirculation kom tshem tawm cov thermal stratification. Thermocouples nyob ntawm ntau qhov tob thiab qhov chaw muab cov lus qhia xav tau rau kev tswj cov txheej txheem.
