Lub zog qaug zog ntawm additively manufactured GR5 titanium alloy raws li kev sib txawv tom qab ua tiav
Cov kev sib txawv tom qab ua tiav, xws li kev kho cua sov (HT), kub isostatic nias (HIP), laser deg hloov kho, thiab lwm yam, feem ntau yog siv los txhim kho kev ua tau zoo ntawm cov khoom siv ntxiv. Muaj qee qhov kev tshawb fawb sim ua kom zoo dua thiab kawm txog qhov cuam tshuam ntawm cov txheej txheem tom qab sib txawv ntawm kev qaug zog ntawm cov khoom siv ntxiv uas tsim los. Txawm li cas los xij, nws tsis paub meej tias dab tsi yog qhov tseem ceeb cuam tshuam rau kev ua haujlwm qaug zog ntawm cov khoom tsim tawm titanium ntxiv, yog li kev pom zoo tom qab ua txoj hauv kev los txhim kho lub zog qaug zog ntawm cov khoom tsim tawm titanium alloys tseem tsis tau txiav txim siab. Tsis tas li ntawd, cov txiaj ntsig ntawm kev siv kev kho cua sov ua ntej kev kho HIP ntawm kev txhim kho qaug zog, tshwj xeeb tshaj yog rau Ti-6Al-4V alloy, tsis tau tshawb nrhiav.
Kab lus no kawm thiab sib piv cov tensile thiab qaug zog zog ntawm Ti-6Al-4V alloy npaj los ntawm hmoov txaj laser xaiv melting txoj kev nyob rau hauv thawj lub xeev, kho cua sov lub xeev thiab kub isostatic nias lub xeev. Ua tiav qhov kev tshawb nrhiav qhov khoob hauv daim teb no.
Thawj lub xeev Ti-6Al-4V alloy tau los ntawm 3D luam ntawv muaj lub zog siab tshaj plaws, lub zog tensile thiab hardness; lub Ti-6Al-4V alloy nyob rau hauv kub isostatic nias kub kho tshuab ua tej yam kev mob (HT + HIP + M) muaj zog nyob rau hauv cov nqe lus ntawm lub zog. Tsawg, tab sis muaj qhov siab tshaj plaws ductility. Qhov no yog vim lub coarsening ntawm lath thiab decomposition ntawm ' martensite qauv thiab txo cov theem ciam teb dislocation ceev thaum kho cua sov. Cov ntaub ntawv tshwj xeeb zoo li qub thiab tensile ductility cov ntaub ntawv tau qhia hauv Table 1.
Table 1 Static zog thiab tensile zog tau txais los ntawm txawv post-processing txoj kev ntawm additively manufactured titanium alloys. AB sawv cev rau lub xeev pib, HT sawv cev rau lub xeev tom qab kev kho cua sov ntawm 850 degree rau 2 teev, thiab HIP sawv cev rau lub xeev tuav ntawm 920 degree thiab 120MPa rau 2 teev.
Daim duab 1 Microstructure ntawm additively manufactured titanium alloy nyob rau hauv txawv post-processing tej yam kev mob. (a) AB: Initial state (b) HT: 850 degree rau 2 teev; (c) HIP: 920 degree, 120MPa rau 2 teev; (d) HT + HIP xeev. Cov kev taw qhia uas cim rau ntawm sab xis ntawm daim duab yog cov kev taw qhia stacking ntawm cov khoom thaum luam ntawv.
Daim duab 1 qhia cov microstructure ntawm additively manufactured titanium alloys nyob rau hauv txawv post-processing xeev. Daim duab no yog ib daim duab backscattered nyob rau hauv ib tug electron microscope. Hauv daim duab no, theem nrog dawb sib piv yog theem, thiab theem nrog dub thiab grey sib piv yog theem. Cov yam ntxwv microstructural tshwj xeeb ntawm cov ntawv luam tawm titanium alloys yog cim nyob rau hauv daim duab, nrog rau cov thawj theem grain ciam teb thiab Widmanstatten qauv. Cov txiaj ntsig hauv daim duab 2 qhia TEM cov txiaj ntsig hauv qab kev ua haujlwm sib txawv.
Daim duab 2 TEM soj ntsuam tau ntawm additively manufactured Ti-6Al-4V nyob rau hauv txawv post-processing xeev thiab thawj lub xeev. (a) AB; (b) HT; (c) AB + HIP; (d) HT + HIP.
Kev kho cua sov, uas yog, HT + HIP cov xwm txheej, tau thov ua ntej kub isostatic nias, thiab tom qab ntawd cov qauv saum npoo tau polished (HT + HIP + M). Nws tau pom tias lub zog qaug zog ntawm Ti-6Al-4V tau txhim kho tau zoo nyob rau hauv cov xwm txheej no, piv nrog Tus mob thawj zaug tau txhim kho los ntawm yuav luag 5 zaug, thaum kho cua sov ib leeg nce nws lub zog qaug zog los ntawm yuav luag 3 lub sij hawm piv rau qhov qub. Qhov tshwj xeeb SN nkhaus yog qhia hauv daim duab 3.
Daim duab 3 SN nkhaus nyob rau hauv cov txheej txheem tom qab sib txawv. Cov txheej txheem tom qab ua tiav tshwj xeeb yog qhia hauv cov lus dab neeg nyob rau sab xis sab xis ntawm daim duab. Ntawm lawv, M txhais tau hais tias tus qauv saum npoo yog polished, thiab tsis muaj M txhais tau hais tias tus qauv nto yog nyob rau hauv lub xeev tom qab luam ntawv tiav.
Kev kho cua sov (HT) thiab kub isostatic nias (HIP) ua rau muaj kev hloov pauv hauv microstructure nyob rau hauv lub additively manufactured Ti-6Al-4V alloy. Tom qab kev kho cua sov, lub metastable acicular ' martensite qauv decomposes rau hauv + lamellar qauv, thiab cov thickness ntawm lamellae maj mam nce raws li qhov kub thiab txias kev kho mob nce. Kev kho HT txhim kho lub zog qaug zog piv nrog lub xeev AB, feem ntau yog vim muaj kev cuam tshuam ntawm -colonies (cov pawg siv lead ua nrog cov kab lis kev cai zoo sib xws) hauv cov qauv + lamellar thiab cov tensile residual stress qhia los ntawm 3D luam ntawv txheej txheem. kev so. Yog vim li cas vim li cas kev kho HIP txhim kho lub zog qaug zog tsis yog tsuas yog ob lub ntsiab lus hais hauv HT lub xeev, tab sis kuj txhawb kev tshem tawm qhov tsis xws luag hauv cov khoom siv. Cov kev kuaj X-ray μCT tshwj xeeb tau pom hauv daim duab 4 hauv qab no.
Daim duab 4 Peb-dimensional reconstruction renderings ntawm internal defects nyob rau hauv txawv post-processing xeev. (a) AB; (b) HT; (c) AB + HIP; (d) HT + HIP.
Cov ntaub ntawv pov thawj:
Bhandari L, Gaur V. Cov kev sib txawv tom qab ua tiav los txhim kho kev qaug zog ntawm cov khoom ntxiv ua Ti-6Al-4V alloy[J]. International Journal of Fatigue, 2023: 107850.
