Xwm txheej txheej txheej txheej
Titanium yog reactive heev ntawm qhov kub siab, tshwj xeeb tshaj yog thaum raug huab cua thaum lub sij hawm ua kub, kho cua sov, los yog casting. Thaum kub siab tshaj li ntawm 590–620℃(1100–1150℃F), titanium reacts nrog oxygen thiab nitrogen los ua ib tug brittle, oxygen-enriched nto txheej hu uaalpha cas(los yog cov txheej txheem tshuaj tiv thaiv). Cov txheej no feem ntau yog 50-300 μm tuab thiab muaj cov kab mob sib kis xws li oxygen thiab nitrogen, uas txo cov ductility thiab qaug zog. Cov ntaub ntawv alpha uas tsis tau tshem tawm tuaj yeem txo qhov qaug zog lub neej txog li 50% thiab yog li ntawd yog ib qho kev txhawj xeeb tseem ceeb rau cov qauv thiab qaug zog- cov khoom tseem ceeb.
Txoj Kev Tshem Tawm Tseem Ceeb
Cov txheej txheej txheej txheej yuav tsum raug tshem tawm tag nrho ua ntej machining, vuam, lossis kev pabcuam. Cov kev kho mob poob rau hauv peb pawg: mechanical method, chemical method, and electrochemical method.
1. Mechanical Methods
Sandblasting (Grit Blasting):Dawb corundum feem ntau yog siv rau sandblasting titanium nto. Lub blasting siab yuav tsum tau ua tib zoo tswj- feem ntau qis dua 0.45 MPa- kom tsis txhob muaj cua sov ntau dhau. Thaum txhaj tshuaj siab dhau lawm, qhov cuam tshuam ntawm cov khoom abrasive ntawm lub titanium nto ua rau muaj qhov kub hnyiab, ua rau qhov kub thiab txias hauv cheeb tsam tuaj yeem hnov mob rau saum npoo thiab tsim cov kab mob sib kis. Lub sijhawm sandblasting ntawm 15-30 vib nas this feem ntau yog txaus kom tshem tawm cov xuab zeb nplaum, txheej txheej sintered, thiab ib nrab oxide txheej. Txawm li cas los xij, sandblasting ib leeg tsis tuaj yeem tshem tawm cov tshuaj tiv thaiv txheej; nws ua haujlwm ua ntej -kev kho mob ua ntej tshuaj pickling.
Machining thiab sib tsoo:Precision sib tsoo lossis tig yog feem ntau ua haujlwm los tshem tawm cov txheej txheem alpha thiab tswj qhov tob ntawm cov hlau hauv qab nws kom tshem tawm txhua qhov chaw embrittled. Cov lus qhia tshwj xeeb feem ntau hais txog qhov tsawg kawg nkaus tshem tawm qhov tob kom ua tiav kev tshem tawm cov txheej txheem cuam tshuam. Txawm li cas los xij, kev sib tsoo yuav tsum tau ua tib zoo tswj- siab dhau ua kom muaj cua sov uas tuaj yeem tsim cov txheej txheem tshiab ntawm alpha. Cov txheej txheem sib tsoo yog qhov qeeb thiab tshem tawm cov khoom siv hauv cov nqaim strips, feem ntau xav tau ntau qhov kev hla hla tag nrho saum npoo.
2. Cov txheej txheem tshuaj
Pickling (Acid Etching):Pickling yog txoj kev ceev tshaj plaws thiab zoo tshaj plaws kom tshem tawm cov tshuaj tiv thaiv txheej txheem tag nrho yam tsis muaj qhov paug ntawm qhov chaw nrog lwm cov khoom. Feem ntau siv ob lub tshuab acid:
HF-HNO₃ system:Qhov no yog qhov nyiam pickling kua. HF concentration yog feem ntau 3-5%, thiab HNO₃ concentration yog 15-30%. HNO₃ ua raws li tus neeg sawv cev oxidizing los tiv thaiv ntau dhau titanium dissolution thiab hydrogen absorption, thaum tseem ua kom lub ntsej muag ci. Lub kaw lus no muaj peev xwm nqus dej tsawg dua piv rau HF-HCl cov kev daws teeb meem, ua rau nws muaj kev nyab xeeb rau cov khoom siv.
HF-HCl system:Thaum siv tau zoo rau pickling, qhov system no muaj peev xwm nqus tau hydrogen ntau dua, uas tuaj yeem ua rau hydrogen embrittlement -kev txhawj xeeb loj rau titanium alloys. Yog li ntawd, nws tsis tshua muaj siv nyob rau hauv daim ntawv thov tseem ceeb.
Cov kua qaub piv yog qhov tseem ceeb: cov kev daws teeb meem feem ntau khaws cia ntawm 5: 1 txog 10: 1 ntim feem pua ntawm HNO₃ rau HF (raws li cov kua qaub hauv Tshuag) kom txo qis hydrogen khaws, nyob ntawm seb hom alloy. Tom qab sandblasting, pickling tuaj yeem tshem tawm tag nrho cov tshuaj tiv thaiv sab nrauv ntawm titanium daim hlau thiab cov pas nrig.
Tshuaj Milling:Cov tshuaj milling yog siv rau kev tshem tawm cov khoom sib xws, alpha- tshem tawm cov ntaub ntawv ntawm forgings, thiab kev ua kom zoo dua qhov chaw uas tsis tuaj yeem ua tau. Cov txheej txheem cuam tshuam nrog rau qhov chaw nyob rau hauv cov tshuaj etchants tswj nruj nreem tswj tus nqi, lub sij hawm, kub, thiab concentration. Tom qab etching, qhov chaw tau nruab nrab thiab yaug kom tsis txhob dhau -etching lossis pitting. Txoj kev no yog qhov tshwj xeeb tshaj yog muaj txiaj ntsig rau cov khoom hauv aerospace nrog cov geometry nyuaj.
Tshuaj Polishing:Kev sib xyaw ntawm HF thiab HNO₃ hauv cov kev faib ua feem tuaj yeem siv rau cov tshuaj polishing. HF ua raws li tus neeg sawv cev txo kom yaj cov titanium hlau thiab theem ntawm qhov chaw, thaum HNO₃ (ntawm qhov ntau tshaj 10%) ua lub luag haujlwm oxidizing los tiv thaiv ntau titanium dissolution thiab hydrogen absorption thaum tsim cov nyhuv ci. Cov txheej txheem yuav tsum muaj siab concentration, tsis tshua muaj kub, thiab luv polishing lub sij hawm (1-2 feeb). Txoj kev no yog tshwj xeeb tshaj yog haum rau cov txheej txheem nyuaj xws li titanium hniav nyiaj hniav kub moj khaum, raws li nws polishes tag nrho cov nto nyob rau hauv kev sib cuag nrog cov tshuaj tsis hais txog ntawm hardness los yog cov duab.
3. Cov txheej txheem electrochemical
Electrolytic Polishing:Kuj tseem hu ua electrochemical lossis anodic dissolution polishing, txoj kev no ntsib teeb meem nrog titanium vim nws cov conductivity tsawg thiab muaj zog oxidation nyiam. Cov pa dej aqueous acidic electrolytes (xws li HF-H₃PO₄ lossis HF-H₂SO₄) feem ntau tsis muaj txiaj ntsig vim tias titanium anode oxidizes tam sim ntawd raws li daim ntawv thov voltage, tiv thaiv anodic dissolution. Txawm li cas los xij, anhydrous chloride electrolytes ntawm qhov tsis tshua muaj hluav taws xob tau pom cov txiaj ntsig zoo polishing, muaj peev xwm tsim cov iav tiav ntawm cov qauv me me. Rau cov txheej txheem nyuaj, kev tshawb fawb ntxiv yog xav tau los txhim kho cathode geometry thiab ntxiv cathode configurations.
Patented Electrochemical Conditioning:Cov txheej txheem electrochemical puas (tsim los ntawm MetCon) hloov cov tsoos sib tsoo, machining, thiab acid pickling nrog qis - tawm los - poob electrochemical cov kauj ruam. Cov txheej txheem no siv cov khoom siv hluav taws xob thiab cov khoom siv tsis zoo los tshem tawm cov txheej txheem alpha nrog kev tswj xyuas meej. Tsis zoo li cov txheej txheem siv tshuab uas tshem tawm tag nrho cov khoom mus rau qhov tob tshaj plaws tawg, cov txheej txheem electrochemical nyiam tawm tsam cov npoo tawg, smoothing thiab feathering lawv thaum khaws cov hlau ntau ntau. Cov txheej txheem tshem tawm tsuas yog 0.5-3% ntawm cov khoom siv rau ib kauj ruam txias piv rau 3-7% rau cov qauv siv, txhim kho cov khoom tiav tiav los ntawm 10-20% lossis ntau dua. Txoj hauv kev no tseem tshem tawm cov pov tseg phom sij cuam tshuam nrog cov tshuaj qaub qaub.
Txheej Txheem Txheej Txheem thiab Kev Tswj Xyuas Zoo
Txhawm rau kom tshem tawm tag nrho cov txheej txheem txheej txheej saum npoo av, cov txheej txheem raug ua ntu zus yog:
Initial mechanical kev kho mob:Sandblasting los yog sib tsoo kom tshem tawm tag nrho qhov chaw paug thiab oxide nplai
Tshuaj descaling:Molten kub alkaline ntsev descaling los yog kho abrasive rau hnyav oxide txheej
Acid pickling:HF-HNO₃ daws kom tshem tawm tag nrho cov txheej txheem alpha
Kev txheeb xyuas zaum kawg:Kev soj ntsuam pom thiab kuaj microhardness kom paub meej tias kev tshem tawm tag nrho cov ntaub ntawv alpha, raws li qhov yuav tsum tau ua los ntawm cov lus qhia tshwj xeeb xws li NASA PRC-5010 thiab ASTM B600
Kev txiav txim siab tseem ceeb
Hydrogen Embrittlement:Titanium thiab nws cov alloys raug cuam tshuam rau hydrogen embrittlement. Thaum kho cua sov, pickling, thiab tshuaj milling, yuav tsum tau saib xyuas kom tsis txhob muaj hydrogen ntau dhau. HF-HNO₃ system yog qhov zoo dua vim tias nws txo qis hydrogen nqus piv rau lwm cov kua qaub.
Vacuum Thaum tshav kub kub kho:Kev kho cua sov zaum kawg ntawm cov khoom tiav yuav tsum ua kom zoo tshaj plaws hauv lub tshuab nqus tsev kom tsis txhob tsim cov ntaub ntawv alpha tag nrho. Yog tias siv lub tshuab nqus tsev cua sov, kev siv lub tshuab ua ntej lossis pickling tuaj yeem zam tau. Txawm li cas los xij, kev huv ntawm qhov chaw yog qhov tseem ceeb tshaj -txawm cov ntiv tes lossis cov roj seem tuaj yeem ua rau cov ntaub ntawv alpha tsim hauv lub tshuab nqus tsev, thiab cov chlorides los ntawm cov tshuaj ntxuav tau cuam tshuam nrog kev ntxhov siab corrosion ntawm titanium.
Kev Ntsuas Metallographic:Rau kev ruaj ntseg zoo, Kroll's reagent (1-3% hydrofluoric acid ntxiv rau 2-6% nitric acid nyob rau hauv dej) feem ntau yog siv los qhia txog microstructure. Rau kev tshawb nrhiav alpha case, Kroll's etch yog ua raws li cov tshuaj ammonium bifluoride uas stains tag nrho cov qauv tshwj tsis yog rau cov ntaub ntawv alpha, ua rau cov txheej nkig kom pom tseeb rau kev tshuaj xyuas.
