Cov yam ntxwv ntawm cov khoom thiab formability
Titanium thiab nws cov alloys nthuav tawm cov khoom siv tshwj xeeb uas cuam tshuam rau lawv tus cwj pwm sib sib zog nqus. Ntshiab titanium muaj cov ductility siab tsim nyog rau kev sib sau txias, nrog rau qhov tshwj xeeb siab ib txwm anisotropy (r- tus nqi) ntawm kwv yees li 5, uas yog qhov zoo rau cov ntawv hlau ua haujlwm. Qhov siab r- tus nqi no ua rau cov khoom siv los tiv thaiv thinning thaum lub sij hawm deformation, ua rau nws muaj peev xwm tsim tau sib sib zog nqus - khob cylindrical hauv qab los ntawm txoj kev xovxwm.
Ntawm cov titanium alloys, beta titanium alloys xws li Ti-15V-3Cr-3Sn-3Al (Ti-15-3) ua kom pom kev sib piv zoo ductility rau qhov txias txias, tab sis lawv feem ntau ua haujlwm qis dua li cov titanium ntshiab. Lub hexagonal close-packed (HCP) siv lead ua qauv ntawm alpha-titanium alloys nthuav tawm cov kev cov nyom tshwj xeeb hauv cov lej simulation, xav tau cov qauv khoom tshwj xeeb xws li Barlat 1989 qauv nrog cov kab nrib pleb rau ob qho tib si strain hardening thiab strain-dependent plastic strain ratios kom txaus ntes cov khoom yas.
Cov kev sib tw tseem ceeb hauv kev kos duab sib sib zog nqus
Qhov teeb meem tseem ceeb hauv titanium sib sib zog nqus yogqaug dab peg thiab gallingvim titanium lub siab tshuaj reactivity nrog cov khoom siv. Qhov teeb meem no tau dhau los ua qhov tshwj xeeb hauv kev ua haujlwm hnyav xws li kev sib sib zog nqus nqus thiab ironing, qhov twg cov titanium tshiab tuaj rau hauv kev sib cuag ncaj qha nrog cov tuag thiab xuas nrig ntaus. Txhawm rau txo qhov teeb meem no, ntau lub tswv yim tau tsim:
Oxide txheej cua sov: Cua sov qhov khoob hauv huab cua los tsim cov txheej txheem oxide tiv thaiv (kwv yees li 0.0015 hli tuab ntawm 750℃rau 0.3 ks) tiv thaiv cov hlau ncaj qha - mus rau - hlau sib cuag ntawm titanium dawb paug thiab cov cuab yeej tsim. Txoj kev no tau ua kom muaj kev vam meej multistage sib sib zog nqus nqus ntawm ntev beta titanium alloy khob tsis muaj qhov nruab nrab annealing.
Kev kho deg thiab lubricants: Teflon spray coatings thiab lwm yam tshwj xeeb lubricants feem ntau siv los tiv thaiv kev ntes thaum lub sij hawm tsim.
Cov cuab yeej tsim kho tshiab: Cov menyuam pob tuag nrog lub xub pwg nyom thiab cov pob steel tau tsim los txo kev sib txhuam thiab ua kom muaj kev sib txuam ntawm cov khob corrugated titanium nrog txwv qhov sib piv (LDR) ntawm 2.5 lossis ntau dua.
Txheej txheem Parameter thiab tsim txwv
Thaum lub sij hawm sib sib zog nqus nqus, cov ntawv titanium tau txais kev sib xyaw ua ke thiab ncab raws li qhov khoob yog rub hla lub vojvoog tuag rau hauv qhov tuag kab noj hniav. Cov txheej txheem yuav tsum tau ua tib zoo tswj kom tsis txhob muaj ob hom kev ua tsis tiav:buckling/wrinklingvim compressive circumferential stresses hauv cheeb tsam flange, thiabtensile kua muagnyob rau hauv lub khob phab ntsa vim ntau stretching. Yog li, tus tsim yuav tsum xav txog ob qho tib si compressive thiab tensile yield zog ntawm cov khoom titanium.
Preheating ntawm daim ntawv dawb paug feem ntau yog siv los txhim kho formability, tshwj xeeb tshaj yog rau siab dua -lub zog titanium alloys. Kev tswj qhov kub thiab txias yog qhov tseem ceeb, vim tias cov qauv siv lead ua ntawm qee cov alloys (xws li Ti-15-3) hloov mus rau theem beta ntawm qhov kub siab tshaj li ntawm 720 degree, hloov pauv tus cwj pwm deformation.
Advanced Forming Techniques
Rau tsim lub khob ntev cylindrical,multistage sib sib zog nqus kos duab nrog nruab nrab ironingtau ua pov thawj zoo. Txoj hauv kev no tsis yog tsuas yog ua tiav lub khob qhov tob xwb tab sis kuj txhim kho qhov roughness los ntawm cov nplej ua kom zoo. Tom qab-kev kho cov thermomechanical tuaj yeem txhim kho cov khoom siv kho tshuab thiab qhov zoo ntawm cov khob kos.
Cov lej simulation siv cov ntsiab lus tseem ceeb (xws li LS-Dyna) tau dhau los ua cov cuab yeej tseem ceeb rau kev kwv yees ua tus cwj pwm, ua kom zoo dua cov cuab yeej geometry, thiab txo nqi kev sim lub cev. Kev tsim cov duab txwv kev txiav txim siab los ntawm Nakajima txoj kev yog ua haujlwm rau kev twv ua ntej tsis ua haujlwm, nrog cov txheej txheem yooj yim kom tau txais kev txwv txiav cov kab mob ntawm cov qauv ntsuas tensile.
