1. Forging Thermal effect
Tom qab cov qib ntawm cov high-kub typot tau forged ntawm lub tshuab FORT Tom qab kev kho cua sov, nws macrostructure tau pom tias yog ib qho qauv ua kom zoo nkauj, thiab nws cov microsiaxed, uas yog qhov qauv zoo tshaj plaws ntawm + ob-theem titanium alloy. Daim duab microstructure yog qhia hauv daim duab 1a. Tom qab lub φ 165 mm bar tau pom thiab txiav, nws tau rhuab ntawm 5 {{}}}} mm φ 110 mm φ 110 mm φ 110 mm square billet ntawm ib 30 kn hydraulic rauj. Thaum cov plaub fab xwm fab tau tom qab tsis taus thiab raug tshuaj xyuas, nws tau pom tias tus tseem ceeb tau pom Crystal. Daim duab microstructure yog qhia hauv daim duab 1B. Lub microstructure yog lath + kev sib hloov, uas yog ib txwm dav dav nrog cov kab ke meej. belongs rau cov qauv overheated hauv titanium alloy. Lub semi-crystal yog 20 txog 30 hli nyob deb ntawm qhov chaw. Daim duab microstructure yog qhia hauv daim duab 1c. Lub microstructure yog lath + equiaevexed + kev sib hloov. Tus naj npawb ntawm eatiaxed yog tsawg tsawg, tus naj npawb ntawm laths loj, thiab muaj cov tsis sib xws muab cov ciaj ciam nplej; Qhov ntau ntawm 0 txog 20 mm los ntawm saum npoo yog fuzzyrystal.
Ib pob ntawm φ80mm tc4 titanium alloy tuav muaj eet astiaxed metreiaxed microstructure (Saib Daim Duab 2, thiab thawj cov ntsiab lus sib luag yog ntau tshaj 70%. Tom qab tuag sau tseg ntawm lub cua sov rauj ntawm 940 degree (alloy transformation point 995 degree), thiab thawj cov ntsiab lus ntawm cov ntsiab lus tsuas yog kwv yees li 15%, uas yog tshwm sim los ntawm overheating ntawm kev forging kub.
Titanium alloys deformed saum toj no theem hloov chaw (+ Kev Hloov Ntaus Ntsuas) kom tau txais pob tawb nrog cov khoom siv tsis zoo thiab cov khoom siv qaug zog. Yog li ntawd, feem ntau Titanium alloy Khoom siv cov qauv kev xav tau ntawm Wead -Thia cov khoom lag luam yog feem ntau sib luag nrog kev ua tau zoo. Yog li ntawd, ze li -Tej thiab {+ - Hom Dual-Phast thiab Forged thaum {8} degree hauv qab theem hloov chaw. Ib tug loj ntawm kev tshawb fawb thiab kev ua engineering tau pom tias nrog kev ua kom muaj cua sov titanium ntau, thaum cov ntsiab lus ntawm laths yog nce ntxiv. Qhov ntawd yog hais, thaum lub duplex titanium alloy yog rhuab hauv qab cov ntsiab lus kub, thiab kev nce qib me me, thiab kev nce qib me me, thiab kev nce qib me me tom qab cua sov tom qab cua sov thiab forging. Thaum cov cua sov thiab forging kub tshaj cov theem hloov pauv ntawm cov qauv titglex
Lub thermal conductivity ntawm titanium yog {{}}. 036cal / cm}. 68W / CLAK K.. Thaum lub sij hawm forging cov txheej txheem ntawm titanium alloy ntawm rauj, vim muaj cov rauj loj heev, thiab muaj zog ntawm lub zog loj heev, thiab muaj peev xwm loj heev ntawm lub zog loj heev, thiab hloov kho cov tshuab hluav taws xob loj heev, thiab hloov pauv mus rau hauv tshav kub hauv lub sijhawm luv luv. Txij li thaum deformation ntawm cov tub ntxhais ntawm billet yog loj dua li ntawm thaj chaw ib puag ncig thiab tseem ua tiav qhov kev ploj mus ntawm lub nroog loj. Thaum overheating yog loj, lub koom haum hloov pauv mus ua ib lub koom haum tsis zoo Hidmanstatten lub koom haum. Tom qab cov saum toj no ob raug dual-pepe titanium alloys tau raug forged los ntawm rauj, cov ntsiab lus tseem ceeb txo tau kom yooj yim. Lub microstructure yog hloov los ntawm ib tug zoo tshaj plaws equiazed qauv rau ib tug neeg txom nyem widmanstatten qauv. Qhov laj thawj tseem ceeb yog qhov titanium alloy yog overheated thaum lub sij hawm nrawm thiab txheej txheem deformation loj.
Thaum lub sij hawm zam deformation ntawm titoric alloy, qhov chaw feem ntau yog thaj chaw deformation, yog li lub chaw nruab nrab yog thaj chaw nrog kub siab tshaj. Qhov ntsuas kub nce nyob rau hauv lub chaw yog siv los ua cov ntsiab lus tseem ceeb rau tsim cov txheej txheem FORGING. Thaum forging titanium alloy nrog kev zam rauj nrog nrawm nrawm nrawm, cov khoom siv hluav taws xob nrawm yuav tsum tau raug tsoo. Nws raug nquahu kom siv xovxwm lossis ceev forging tshuab rau titanium alloy forging yog tias mob tso cai. Cov cuab yeej FORTING FORT muaj qhov nrawm nrawm, thiab cov kab sib zog ntawm cov lej tsis muaj tseeb yog tsawg. Lub teeb meem deformation kub tsim tawm tsis pom tseeb heev. Nyob rau tib lub sijhawm, muaj sijhawm txaus rau deformation tshav kub kom diffuse, uas yuav tsis ua rau muaj kev nce qib tseem ceeb hauv kev txawj kub instantaneous.
2. Lub Koom Haum Tsis Sib
Thaum saib cov microstructure ntawm ib pob ntawm TC17 titanium alloy tuag tsis lees paub, nws tau pom tias muaj cov qauv kev sib tw, thiab cov pa roj sib txawv tom qab quav yeeb yaj kiab) Pob tawb qauv.
Qhov no zoo ntawm kev ntxhib los kuj tseem hu ua loj dawb thaiv. Piv nrog cov kab txaij nplua nuj nyob hauv cov qauv pob tawb, nws yog ntxhib thiab tsis sib xws hauv cov duab. Nws loj hlob los ntawm cov qoob loo nplej rau cov noob qoob loo, tsis tshua muaj kev cuam tshuam, thiab tsis sib luag, thaum lub crystal interface ntawm cov sawb ib txwm muaj kuj yog. Cov kev tshawb fawb tau pom tias microhardness ntawm no coarsy block, yog qhov tsim nyog los tiv thaiv cov qauv tsis sib xws hauv titanium alloy. Thaum lub sij hawm melting thiab cov txheej txheem solary ntawm titilibrium expooming coefficization ua ntej rau cov noob qoob loo rau cov noob qoob loo, yog li sib sau ua kev ntxhib. Cov qauv micro-cheeb tsam uasent segrate yog qhov laj thawj tseem ceeb rau tiam ntawm cov qauv tsis ncaj ncees no.
Micro-region component crystallization segregation is caused by the equilibrium distribution coefficient k0>1 lossis k 0<1. The segregation formed by different solute concentrations in the successive crystallization regions of the alloy is normal segregation. This segregation is difficult to avoid completely, but it can be controlled by appropriate measures. On the one hand, it can be controlled by improving and optimizing the ingot smelting process parameters, and on the other hand, it can be improved and eliminated by appropriate forging processes. In terms of forging process, firstly, during the forging of the ingot, appropriate high-temperature homogenization treatment is used. The microscopic intracrystalline dendrite segregation in the columnar structure area of the ingot is improved and eliminated by homogenization annealing or deformation recrystallization; secondly, during the die forging process of the alloy billet and the finished product, appropriate post-forging cooling methods are used to control it and inhibit the appearance of coarse α blocks in its microstructure. The use of air cooling after the sub-β die forging of the above-mentioned TC17 titanium alloy forgings is the cause of the appearance of coarse α blocks. The post-forging cooling rate is slow, the undercooling degree is small, and the nucleation rate is low, so the α phase has enough time to grow and form coarse α blocks.
Ceev sai txias (dej txias lossis roj txias) tom qab kev zam txim tuaj yeem txo qis lossis cuam tshuam cov tsos ntawm cov ntxhib. Ua kom muaj qhov ua kom txias dua thiab nce qib ntawm supercooling tuaj yeem nce cov nucleation ntawm theem. Txawm hais tias muaj alloy yug cais tawm hauv thaj chaw muaj kev loj hlob, cov theem tsis muaj sijhawm loj hlob thiab sib koom ua ke ntawm tag nrho cov koom haum tau xaus. Tswj tus nqi txias tuaj yeem hloov pauv morphology thiab faib cov theem nag /. Dej txias lossis roj cua txias tom qab forging kho txhua lossis cov koom haum rho tawm cov crystal nuclei rau kev rov ua dua cov txheej txheem kev kho kom sov. Nyob rau hauv tom qab kev kho cua sov, cov dej nag lossis daus ntawm cov inducation ucleation los ntawm cov inducation nucleation ntawm cov kev mob siab ntawm cov thawj coj ntawm thawj thiab theem nrab tau. Lub koom haum no tuaj yeem txhim kho qhov kev nkag tau zoo ntawm cov alloy.
3. CARINITY-TUG TSIS TXAUS SIAB
Thaum lub sij hawm tshuab hluav taws xob ultrasonic soj ntsuam ntawm ib qho batch ntawm φ 70 hli Ta7 titanium alloy tuav, ntau dhau kev puas tsuaj tau pom. Tom qab dissecting qhov chaw tsis taus, qhov ntsuas hluav taws xob tsawg tshuaj xyuas tau ua. Tom qab corrosion, muaj ntau tus ntawm "pits" tau pom nyob rau hauv qhov qis-fais fab tshuaj, feem ntau yog muaj "lub pits" tau pom nyob sab nraud ntawm 1/4 vojvoog ntawm lub bar. Tom qab, cov pits tau pom ntawm lub zog siab thiab pom tias muaj kev cuam tshuam tsis muaj kev tsis xws luag. Cov duab microstructure cov duab ntawm qhov tsis xws muaj nyob hauv daim duab 4. Qee qhov kev tshawb fawb ntseeg tias "qhov" Pit "tshwm sim pom tseeb li lub sijhawm Corrosion nce; Qee qhov kev tshawb fawb ntseeg tias "lub qhov" yuav cuam tshuam nrog cov ntsiab lus tsis huv. Txawm li cas los xij, cov lus pom saum toj no nyuaj los piav txog qhov tshwm sim ntawm kev sim siab ntau dhau ntawm ultrasonic kuaj thiab lub void prenomenon pom nyob rau hauv high-zog tsom xam.
Cov kev coj ua ntau ntawm kev ua pov thawj tau ua pov thawj tias kev zam txim txheej txheem ntawm Ta7 yog qhov phem dua li lwm cov titanium alloys xws li TC4 thiab TC11. Nws yog ntau dua feem ntau yuav tawg thaum lub sij hawm forging dua li lwm cov titanium alloys, thiab tus nqi uas tshaj tawm sai dua. Cov ntaub ntawv hlau xws li titanium thiab aluminium alloys yog nquag mus rau qhov tsim nyog xoob, thiab pob txha tsis zoo (xws li loj hlob loj (xws li superplastic tsim). Lub voids nyob rau hauv Ta7 titanium alloy yog ntxias los ntawm cov hlab loj. Nyob rau hauv tus nqi siab, kev ntxhov siab ntawm Ta7 titanium alloy nce ntxiv piv rau cov xwm txheej zoo li qub, tab sis cov plative txo qis; Raws li tus cwj pwm sib zog nce ntxiv, kev ntxhov siab txoj kev ntxhov siab ntau dua, tab sis muaj tus nqi sib txawv. Thaum tus nqi tseem ceeb tau dhau lawm, cov khoom yuav ua pob txha lov; Thaum tus nqi sib npaug mus txog tus nqi tseem ceeb, ib qho adiabatic shear band yog tsim nyob rau hauv cov khoom siv, thiab micro-voids tau tsim nyob rau hauv pab pawg. Raws li kev txiav txim ntawm kev ntxhov siab sab nraud, cov voids maj mam sib sau ua ke thiab loj hlob thiab txawm tsim micro-kab nrib pleb. Microvoids yog ib txwm tsim raws qhov siab tshaj plaws shear deformation band. Qhov no yog vim tias nyob rau hauv ib cheeb tsam deformation, qhov siab tshaj plaws shear band deforms ua nruj ua tsiv, uas softens cov khoom hauv band thiab ua ib qho chaw zoo rau kev tawg thiab voids. Thaum lub sij hawm Forging txheej txheem, qhov deformation ntawm Central cheeb tsam ntawm Ta7 bar yog qhov kub tshaj plaws, qhov tsis tshua muaj cua sov, thiab qhov kub thiab txias tshaj plaws yog qhov siab tshaj plaws. Yog li ntawd, voids feem ntau yuav tshwm sim thaum deformation loj.
Cov kev tshawb fawb tau pom tias cov ntaub ntawv yas yas ntawm cov ntaub ntawv hlau yog nrog kev hloov pauv, cov qoob loo thiab zuaj kev rov qab ua ke thiab rov qab ua kom zoo nkauj, thiab kev loj hlob ntawm kev loj hlob thiab kev loj hlob. Lis Ciaj Zawv Zawg Zawv Zawg yog lub ntsiab tshuab ntawm cov yas deformation. Cov qoob loo qoob loo ciam teb tuaj yeem ua rau muaj kev ntxhov siab hauv zos thiab tabkaum qhov tshwm sim txuas ntxiv ntawm cov qoob zawv zawg. Thaum kev ntxhov siab kev xav tsis tuaj yeem tshem tawm los ntawm kev tshem tawm cov kev txav, lub void yuav nucleate thiab ces loj hlob. Lub khoob yog nucleates ntawm lub voos hmoov nplej. Raws li qhov deformation nce, lub void pib loj hlob, thiab lub tsis muaj kev loj hlob, tab sis loj hlob hauv ib lub xeev eortiaxed, tab sis loj hlob hauv ib qho kev sib luag. Lub voids yog yooj yim rau diffuse rau cov ciaj ciam nplej uas sib txuas txuas ntxiv mus rau hauv qhov chaw tsis muaj kev ntxhov siab, yog pub rau qhov tsis muaj zog mus rau qhov kev coj ua tensile. Coob tus ntawm cov ntawv sau hais tias "pitting" thiab voids yog nquag tshwm sim thaum lub sij hawm forging txheej txheem ntawm no alloy. Los ntawm kev tsom xam ntawm tsim tshuab ua "pitting" thiab khoob kev tswj hwm qhov kev cuam tshuam tsis zoo, peb tau ua kom tsis txhob muaj kev cuam tshuam nrog kev tsis txaus siab, thiab sim kom tsis txhob muaj kev cuam tshuam nrog lub tshuab hluav taws xob tsis txaus siab, thiab sim kom tsis txhob muaj kev cuam tshuam nrog lub tshuab hluav taws xob tsis zoo Hauv kev tsim khoom.
4. Xaus
Tam sim no, cov qauv Forging tsis xws luag nyob rau hauv titanium alloys tsuas yog pom yooj yim thiab lwm yam yooj yim los nrhiav kev tshuaj xyuas lossis kev sim ultrasonic ntawm titanium alloy khoom. Lawv feem ntau yog tshwm sim los ntawm kev tswj tsis raug ntawm cov txheej txheem tsis raws cai thaum lub sij hawm forging txheej txheem ntawm titanium alloy khoom. Yog li ntawd, hauv cov txheej txheem Forging, nws yog ib qho tsim nyog los xaiv qhov kev tsis txaus ntseeg (Forging cov khoom siv), cua sov nrawm tom qab forging raws li cov yam ntxwv sib txawv ntawm titanium alloy cov ntaub ntawv.
