Kev nce qib ntawm EBM tsim TC4 Titanium Alloy

Ua ntej, 3D qauv ntawm ib feem yog hlais thiab txheej raws li ib tug tej thickness los ntawm Magicsl9. Tom qab ntawd, EBM system sib npaug sib npaug ntawm cov hmoov hlau alloy mus rau qee qhov tuab ntawm lub substrate, thiab siv cov kab hluav taws xob uas tsim los ntawm qhov tam sim no dhau los ntawm tungsten hlau raws li qhov chaw tshav kub. Nyob rau hauv qhov kev txiav txim ntawm lub focusing coil thiab electromagnetic deflection kauj, cov hmoov hlau alloy ntawm lub substrate yog ua tiav. Luam theej duab. Txhua lub sij hawm lub tshuab hluav taws xob scans thiab yaj ib txheej, lub workbench poob los ntawm ib txheej qhov siab, thiab tom qab ntawd cov hmoov yog kis dua. Cov kab hluav taws xob hluav taws xob scans thiab yaj cov txheej txheem ntau zaus, thiab txhua txheej txheej txheej ua rau tag nrho. Tag nrho cov txheej txheem tsim khoom yog nqa tawm hauv ib puag ncig lub tshuab nqus tsev, kom tsis txhob muaj titanium alloy raug oxidized thaum ua. Tom qab kev tsim khoom tiav, EBM system siv cov khoom tawm ntawm lub tsev tsim thiab muab tso rau hauv cov hmoov rov qab. Cov cua kub siab yog siv nyob rau hauv PRS kom tshem tawm cov hmoov adhering rau saum npoo ntawm qhov chaw, thiab thaum kawg tau molded qhov chaw nrog ib tug du nto.

Cov tsis tseem ceeb ntawm EBM thev naus laus zis suav nrog cov kab hluav taws xob hluav taws xob tam sim no, acceleration voltage, scanning speed, layer thickness, scanning line spacing and focus them. Los ntawm kev kho cov kev txwv no, qhov sib txawv ntawm lub zog tuaj yeem tau txais, xws li nce cov kab hluav taws xob tam sim no lossis txo qhov nrawm nrawm. Lub zog ceev dua tuaj yeem tau txais. Tus nqi ntawm lub zog ceev heev cuam tshuam rau microstructure, tsis xws luag thiab txhua yam khoom ntawm molded qhov chaw. Tsim nyog lub zog ntom ntom yuav ua rau cov alloy muaj cov khoom siv zoo dua qub. Vim yog cov txheej txheem tsim tshwj xeeb ntawm EBM thev naus laus zis, microstructure thiab mechanical zog ntawm EBM tsim TC4 titanium alloy tsim qhov sib txawv ntawm cov khoom tsim tawm (xws li forging) TC4 titanium alloy tsim qhov chaw.

2.1 Microstructure thiab influencing yam ntawm EBM tsim TC4 titanium alloy

Qhov kub hloov ntawm EBM tsim TC4 titanium alloy thaum lub sij hawm tsim cov txheej txheem cuam tshuam nws cov microstructure. Ua ntej, cov hmoov yog melted nyob rau hauv qhov kev txiav txim ntawm lub electron beam, thiab cov kua alloy kub mus txog 1700 degree, uas yog ntau dua li theem hloov kub ntawm TC4 titanium alloy (995 degree). Thaum lub sij hawm no, cov kua alloy yog tsim los ntawm thawj cov nplej; Tom qab ntawd, raws li cov kab hluav taws xob txav mus deb, cov kua hlau ua kom txias sai rau qhov kev tsim kho kub (feem ntau 650-700 degree) kom nyob ruaj khov thiab ua kom ruaj khov. Thaum lub sij hawm no, cov alloy undergoes → + , thiab lub koob zoo li theem thiab columnar theem precipitate. A1-Bermani et al. ntseeg hais tias thaum qhov txias txias yog siab tshaj 410 degree / s nyob rau theem no, metastable ' martensite yuav precipitate, uas yuav decompose mus rau hauv ib tug + txheej txheej tom qab raug mus rau ib tug kub ib puag ncig rau lub sij hawm ntev, thiab feem ntau ntawm nws yuav yog. Fine koob zoo li laths, nrog ib feem me me ntawm theem. Tom qab ntawd cov tsim TC4 titanium alloy yog maj mam txias los ntawm kev tsim kho qhov kub thiab txias mus rau chav tsev kub, thiab cov hlau microstructure tsis hloov pauv loj heev thiab tseem muaj + theem. Lub microstructure ntawm EBM tsim TC4 titanium alloy thiab forging tsim TC4 titanium alloy yog pom nyob rau hauv daim duab 2.

Cov kws tshawb fawb hauv tsev thiab txawv teb chaws tau ua ntau yam kev tshawb fawb txog cov microstructure ntawm EBM-tsim TC4 titanium alloys thiab pom tias yam xws li molding txheej txheem tsis, txoj hauj lwm ntawm molded qhov chaw, thiab qhov luaj li cas ntawm molded qhov chaw yuav cuam tshuam tus nqi cua txias. lub alloy thaum lub sij hawm molding txheej txheem, yog li cuam tshuam nws cov grain loj. Hrab et al. pom tias, nyob rau hauv cov xwm txheej ntawm kev ua kom pom tseeb tias lub zog yaj tuaj yeem ua kom muaj qhov loj me ntawm Molten pas dej kom tsawg, tus nqi txias kom nce, thiab yog li ntawd, finer particles yuav precipitated. lath thiab beta theem. Murr et al. thiab Wang et al. pom tias microstructure ntawm EBM-tsim TC4 titanium alloy sib txawv ntawm qhov chaw sib txawv. Raws li pom nyob rau hauv daim duab 3, txoj hauj lwm nrog ib tug qis deposition qhov siab muaj ib tug ntau dua txias npaum li cas vim hais tias nws yog ze rau lub molding substrate. Nws yog ib qho kev loj hlob tsis ruaj tsis khov thiab nws yooj yim rau precipitate zoo koob zoo li theem; txoj hauj lwm nrog ib tug ntau dua deposition qhov siab muaj ib tug ntau dua txias tus nqi. Qhov tuab ntawm lub lath, qhov loj dua cov nplej; Tom qab tso rau hauv ib qho siab, nws yog nyob rau hauv ib qho chaw ruaj khov, thiab qhov loj ntawm lub lath thiab cov nplej zoo li ruaj khov. Wang et al. kuj tau kawm txog cov nyhuv ntawm molded ib feem loj ntawm lub microstructure ntawm EBM-tsim TC4 titanium alloy thiab pom tias thaum lub sij hawm txheej txheej-los ntawm-txheej txheej melting thiab solidification txheej txheem, cov qauv me me muaj ib tug loj txias npaum li cas, yog li precipitating finer theem. Galarraga et al. tau kawm ntxiv thiab pom tias qhov kev hloov pauv hauv microstructure ntawm EBM molded TC4 titanium alloy muaj feem xyuam rau lub sijhawm nyob hauv chav tsev. Yog hais tias lub sij hawm nyob ntev dhau lawm, nws yuav ua rau qhov siab ntawm deposition nyob rau hauv qab ntawm deposition qhov siab yuav qis dua thiab lub microstructure yuav coarser. tshwm sim. cov

2.2 Qhov tsis xws luag ntawm EBM molded TC4 titanium alloy

Vim yog kev xaiv tsis raug ntawm cov txheej txheem tsis raug lossis cov txheej txheem cuam tshuam, EBM tsim TC4 titanium alloy qhov chaw tuaj yeem tsim ntau yam tsis xws luag. Zhai et al. pom tias muaj ob yam tsis xws luag hauv microstructure ntawm EBM-molded TC4 titanium alloy: ib qho yog qhov pore tshwm sim los ntawm cov roj argon entrained hauv cov hmoov tsis zoo; Lwm qhov yog qhov pore tshwm sim los ntawm kev ua tsis zoo ntawm cov hmoov hlau alloy.

Gong et al. cais TC4 titanium alloy tsis xws luag rau hauv ob pawg loj raws li lub zog ntom ntom ntawm cov khoom siv hluav taws xob. Thaum lub zog ntom ntom dhau lawm, nws tsis txaus los ua kom tiav Molten pas dej rau hauv moltating melting tsis meej los ntawm qee qhov ntau ntawm cov hws pores. Thaum lub zog ntom yog dhau lawm, kev kub tshav kub nce siab sai. Thaum cov hmoov melts, nws spheroidizes nyob rau hauv qhov kev txiav txim ntawm nto nro (lub thermal conductivity ntawm cov hmoov yog tsawg), yog li tsim pores. Kahnert et al. pom tias yog lub zog tawm tswv yim siab dhau lawm, tsis yog tsuas yog qhov zoo ntawm cov khoom molded yuav deteriorate, tab sis nyob rau hauv cov xwm txheej hnyav, lub hom phiaj tshuab ntawm cov hmoov txheej txheej yuav tsum tsis ua hauj lwm, yog li ntawd cov txheej txheem tsim nws tus kheej yuav tsum tau nres. Tsis tas li ntawd, thaum lub teeb hluav taws xob hluav taws xob tam sim no dhau ntawm qhov chaw pib, cov hmoov hlau alloy yuav raug tshuab, tawm hauv cov pores tsis zoo nyob rau hauv txheej. Nyob rau hauv cov xwm txheej hnyav, tag nrho cov hmoov txaj yuav vau, raws li pom hauv daim duab 5; Kev npaj ntawm hmoov txaj Thaum tshav kub kub yog siv los txhim kho nws cov adhesion, kov yeej lub thrust ntawm lub electron beam ntawm cov hmoov hlau alloy, thiab tsis txhob hmoov av. Cov teeb meem yuav muaj kev cuam tshuam tsis zoo rau cov khoom siv ntawm C4 titanium alloy. Cov txheej txheem EBM yuav tsum tau ua kom zoo dua qub, xws li kev tswj xyuas qhov nrawm, kho cov kab sib nrug deb, thiab txhim kho cov kab hluav taws xob hluav taws xob tam sim no, txhawm rau txo qhov tshwm sim ntawm qhov tsis xws luag.

3.1 Tensile zog ntawm EBM tsim TC4 titanium alloy

Bruno et al. Kawm txog tensile zog ntawm TC4 titanium alloy tsim los ntawm EBM sib sau thiab forging. Txij li thaum EBM tsim TC4 titanium alloy yog feem ntau ua rau pore tsis xws luag thaum lub sij hawm tsim txheej txheem, thiab nws cov microstructure yog unevenly faib, ua rau nws tensile zog, lub siab tshaj plaws yield zog yog 996MPa thiab 919MPa feem, uas yog me ntsis qis dua lub zog ntawm forged TC4 titanium. alloy (lub zog tensile thiab yield zog yog 1034MPa thiab 991MPa feem); Wang et al. kuj tau kawm txog tensile zog ntawm EBM tsim TC4 titanium alloy. Nws tau pom tias nws lub zog tensile yog 1002MPa, yield zog yog 932MPa, thiab elongation yog 14.4%. Txhua qhov ntsuas kev ua tau zoo yog siab dua li ntawm TC4 titanium alloy forgings tom qab annealing thiab kev laus kho.

Muaj qhov tseem ceeb anisotropy hauv cov khoom siv kho tshuab ntawm EBM tsim TC4 titanium alloy. Bruno et al. thiab Hrabe et al. pom tias lub zog tensile ntawm EBM molded cov qauv nyob rau hauv kab rov tav kev taw qhia yog muaj zog tshaj li nyob rau hauv txoj kev ntsug, thaum lub elongation nyob rau hauv kab rov tav kev taw qhia ntawm molded qauv yog me dua lub elongation nyob rau hauv txoj kev ntsug. Qhov no yog tshwm sim los ntawm qhov tsis sib xws B nplej hauv cov hlau: cov qauv molded mas loj hlob nyob rau hauv txoj kev ntsug; qhov tsim ntawm cov nplej me me nyob rau hauv txoj kab rov tav txo qhov kev ntxhov siab ntawm cov ciam teb, yog li ncua qhov pib ntawm cov kab nrib pleb thiab ua rau nws me ntsis ntau dua elongation.

Hrab et al. pom tau hais tias nce lub electron beam scanning ceev (tsis zoo hais txog lub zog ceev) yuav txo tau me ntsis thickness ntawm lub phaj (1.16μm → 0.95un), yog li nce lub tensile zog, yield zog thiab microhardness los ntawm 2% raws. , 3% thiab 2%.

Formanoir et al. tuav EBM-tsim TC4 titanium alloy ntawm 950 degree rau 60 feeb thiab 1040 degree rau 30 feeb raws li, siv ob txoj kev txias: dej txias thiab cua txias. Lub zog tensile thiab lub zog tawm los ntawm cov hlau tau raug txo me ntsis, thiab qhov elongation tsis tau zoo dua. Nws qhia tau hais tias tsuas yog kev tswj hwm qhov tseem ceeb ntawm kev tsim EBM yog txoj hauv kev zoo los txhim kho cov khoom ntawm cov hlau.

3.2 Kev qaug zog ntawm EBM tsim TC4 titanium alloy

Chan et al. kuaj lub neej qaug zog (ntau lub voj voog) ntawm EBM tsim TC4 titanium alloy thiab dov TC4 titanium alloy nyob rau hauv qhov kev txiav txim ntawm alternating dabtsi yog khoov kev nyuaj siab ntawm 600MPa (± 10%). Cov txiaj ntsig tau pom tias lub neej qaug zog ntawm EBM-tsim TC4 titanium alloy tsuas yog 17% ntawm lub neej qaug zog ntawm dov alloy; Qhov tawg ntawm EBM-tsim TC4 titanium alloy yog faib nrog cov pores ntawm cov duab sib txawv vim qhov chaw melting tsis zoo, thiab nws qhov roughness tseem nyob deb. Siab dua dov TC4 titanium alloy, uas yog ib qho tseem ceeb rau nws lub neej qaug zog tsawg.

Tammas-Williams et al. pom tias kub isostatic nias kev kho mob tuaj yeem tshem tawm ntau qhov pores hauv EBM-tsim TC4 titanium alloy, tab sis yog tias muaj qee qhov qhov hauv cov qauv thiab txuas nrog rau saum npoo, cov roj argon siab hauv HIP kev kho mob yuav nkag mus rau hauv qhov tunnels. . Nyob rau hauv lub qhov hws, cov tunnel defects nthuav me ntsis, ua rau kev kho HIP ua tsis tiav; ntxiv ib txheej rau cov qauv ua ntej HIP tuaj yeem tshem tawm qhov tsis xws luag. Shui et al. pom tias tom qab kev kho HIP ntawm EBM-tsim TC4 titanium alloy, txawm hais tias cov laths tau ua tuab dua, qhov kev sib txawv ntawm qhov ntom ntom tau txo qis, thiab lub zog tensile thiab lub zog tawm los ntawm 870MPa thiab 788MPa mus rau 819MPa thiab 711MPa feem, HIP kev kho mob ua rau cov qauv zoo dua qub, Cov txheeb ze ntom ntom ntawm cov alloy tau nce los ntawm 99.3% mus rau 99.8%, txo cov peev txheej ntawm kev pib tawg, yog li ua kom qaug zog ntawm 460boa mus rau 580MPa.