Hauv aerospace, cov khoom siv kho mob, siab- khoom tsim khoom kawg, thiab lwm yam kev lag luam, titanium alloy tau dhau los ua cov khoom tseem ceeb uas tsis tseem ceeb vim nws lub zog zoo heev, tiv thaiv corrosion, thiab lub teeb yuag. Qhov kev ua tau zoo ntawm titanium alloys yog sib cais los ntawm cov txheej txheem kev kho cua sov zoo thiab cov txheej txheem kev hloov pauv uas tshwm sim thaum lub sijhawm ua haujlwm. Niaj hnub no, peb yuav delve rau hauv lub hauv paus kev paub ntawm titanium alloy tshav kub kev kho mob thiab cov ntaub so ntswg transformation, thiab uncover the technical code tom qab no "qhov chaw hlau".
Mechanical transformation law nyob rau hauv kev kho cua sov ntawm titanium alloys
Lub ntsiab lus ntawm kev kho cua sov yog coj kev hloov pauv ntawm cov qauv sab hauv ntawm titanium alloy los ntawm kev tswj qhov kub thiab txias ceev. Los ntawm cua sov kom txias rau kev laus, cov qauv ntawm titanium alloys dhau los ntawm kev hloov pauv uas ncaj qha txiav txim siab qhov kawg ntawm cov khoom.
1. Cov txheej txheem cua sov: Qhov "Trio" ntawm kev rov qab, Recrystallization thiab Theem Hloov
Thaum rhuab, titanium alloys feem ntau yog siv lead ua kev hloov pauv (kev hloov pauv ntawm theem thiab theem) tib lub sijhawm, thiab yog tias nws yog txias -deformed titanium alloy, nws tseem yuav raug rov qab thiab recrystallization txheej txheem, uas ua ke zoo li microstructure tom qab cua sov.
(1) Restoration thiab recrystallization: kho cov qauv deformed thiab optimize cov qauv nplej
Tom qab ua haujlwm txias, titanium alloy muaj ntau qhov teeb meem tshwm sim los ntawm deformation (xws li dislocation thiab vacancy), thiab tom qab cua sov rau qee qhov kub, "rov qab" yuav tshwm sim thawj zaug: ntawm 450 ~ 640℃(qhov kub rov qab yog qis dua qhov ntsuas kub recrystallization), ib feem ntawm cov kev ntxhov siab sab hauv yog tshem tawm los ntawm kev ua haujlwm qeeb ntawm qhov chaw seem, tab sis cov khoom tsis zoo.
Raws li qhov kub thiab txias tseem nce ntxiv, "recrystallization" pib tshwm sim: tshiab tsis yog -distortion- cov nplej dawb isoaxial maj mam tshwm sim hauv cov qauv deformed, thiab cov nplej tshiab no yuav maj mam hloov cov nplej deformed, thaum kawg txo cov hardness ntawm cov khoom thiab rov ua kom nws cov plasticity. Cov yam ntxwv recrystallization ntawm ntau hom titanium alloys yog qhov sib txawv:
• titanium alloy: txwv txias deformation muaj peev xwm, nyuaj rau refine nplej los ntawm deformation thiab recrystallization;
• titanium alloy: muaj zog txias deformation muaj peev xwm, uas muaj peev xwm ua tau ib tug tej yam℃ntawm grain refinement los ntawm deformation thiab recrystallization;
• duplex titanium alloy: Nrog kev pab los ntawm deformation thiab recrystallization, nws tsis tau tsuas yog refine tus qauv, tab sis kuj ntxiv txhim kho plasticity.
(2) theem hloov mus rau theem: qhov "kub hloov" ntawm crystal daim ntawv
Thaum cov cua kub kub tshaj → theem hloov chaw, titanium alloys pib siv lead ua hloov ntawm theem mus rau theem. Siv cov titanium ntshiab ua piv txwv, nws cov theem hloov pauv kub yog li 875 ± 5 degree. Nws yog ib qho tsim nyog sau cia tias Burgers txoj hauj lwm txoj kev sib raug zoo tseem tsis tau hloov pauv thoob plaws ↔ theem hloov, uas muab lub hauv paus tseem ceeb rau cov qauv tunable ntawm titanium alloys.
2. Cov txheej txheem txias: Ceev txiav cov ntaub so ntswg, thiab cov ntaub so ntswg txiav txim siab ua haujlwm
Cov cua txias ceev yog qhov tseem ceeb cuam tshuam rau cov qauv kawg ntawm titanium alloys, thiab nyob rau hauv qhov sib txawv txias ceev, titanium alloys yuav tsim cov microstructure morphology sib txawv kiag li, uas nyob rau hauv lem qhia tau hais tias txawv zog.
(1) Kev ua kom txias qeeb: kev hloov pauv hloov pauv, ua rau theem ruaj khov
Thaum cov titanium alloy maj mam txias los ntawm ib qho -theem cheeb tsam mus rau ob-theem cheeb tsam, cov theem maj mam hloov mus rau theem, thiab ob qho tib si nruj me ntsis raws li Burgers orientation kev sib raug zoo: (110) //(0001); [111] //[11₂0] . Cov qauv tsim los ntawm qhov kev hloov pauv hloov tau zoo heev, uas tsim nyog rau cov xwm txheej nrog cov khoom siv siab ruaj khov.
(2) Kev ua kom txias sai: induce metastable theem los ua txoj hauv kev ntxiv dag zog
Kev ua kom txias sai sai (xws li dej quenching) tuaj yeem cuam tshuam qhov sib npaug ntawm cov txheej txheem kev hloov pauv ntawm titanium alloy qauv, uas tuaj yeem ua rau kev hloov pauv ntawm martensitic, quenched ω theem tsim, supersaturated theem, thiab qhov seem siab siab -kub theem tuav. Cov khoom hloov pauv zaum kawg (xws li ', ", ω, theem supercooled, theem metastable, supersaturated theem) feem ntau yog nyob ntawm cov ntsiab lus ntawm cov ntsiab lus ruaj khov hauv titanium alloy, uas yog "cov ntaub ntawv raw" rau kev laus ntxiv.
3. Aging transformation: metastable theem "transformation" kom ua tau zoo leap
Cov theem metastable uas ua los ntawm cov cua txias ceev tsis ruaj khov, thiab yuav maj mam hloov mus rau theem sib npaug thaum lub sijhawm laus, nrog rau cov theem metastable decomposition, supersaturated theem decomposition thiab lwm yam kev cuam tshuam. Cov txheej txheem no yog qhov laj thawj tseem ceeb vim li cas titanium alloys tuaj yeem ua tiav lub zog thiab hardness txhim kho los ntawm kev kho cua sov, thiab nws tseem yog qhov txuas tseem ceeb hauv kev hloov pauv ntawm titanium alloys los ntawm "cov qauv hauv paus" mus rau "siab- daim ntawv ua haujlwm".
4. Co-kev tshuaj ntsuam thiab kev hloov pauv: "tus neeg tua tsiaj" uas yuav tsum tau ceev faj txog
Kev hloov pauv eutectic ntawm titanium alloys feem ntau pom muaj nyob rau hauv cov alloys uas muaj cov ntsiab lus ruaj khov ntawm titanium thiab ceev eutectic alloys, uas feem ntau ua rau txo qis hauv plasticity ntawm cov khoom, uas tsis zoo rau kev ua haujlwm thiab kev pabcuam ntawm cov khoom. Txawm li cas los xij, los ntawm kev kho mob isothermal ntawm cov ntaub so ntswg tom qab hloov pauv eutectic, nws tuaj yeem hloov mus rau hauv cov ntaub so ntswg uas tsis yog -lamellar ntawm Bain loj, uas txo cov teeb meem ntawm plasticity poob rau qee yam.
5. Kev nyuaj siab-Kev hloov pauv theem: Xauv "Phase Change-Induced Plasticity"
Cov theem metastable yuav hloov mus rau hauv martensitic (piv txwv li, hexagonal martensitic ′, orthorhombic martensitic ") nyob rau hauv strain los yog kev ntxhov siab, txheej txheem hu ua kev ntxhov siab -induced theem kev hloov. ntawm titanium alloys nyob rau hauv cov xwm txheej nyob rau hauv txoj kev nyuaj siab (xws li aerospace structural qhov chaw).
