Impact Resistance thiab Long-Temperature High-Temperature Degradation ntawm Qib 5 Titanium Alloy (Ti‑6Al-4V)
Qib 5 titanium alloy, feem ntau hu ua Ti‑6Al-4V, yog cov siv dav tshaj plaws alpha-beta titanium alloy hauv aerospace, marine, kev kho mob, thiab kev lag luam engineering. Nws qhov kev ua tau zoo nyob rau hauv kev cuam tshuam kev thauj khoom thiab kev pabcuam kub kub mus ntev yog qhov tseem ceeb rau kev nyab xeeb thiab kev pabcuam lub neej. Hauv qab no yog cov ncauj lus kom ntxaws tsom xam ntawm nws cov kev cuam tshuam tsis kam thiab kev kub siab lub zog tuav.
Ua ntej, kev cuam tshuam kev cuam tshuam yog hais txog lub peev xwm ntawm cov khoom siv los nqus lub zog thiab tiv thaiv kev puas tsuaj nyob rau hauv lub zog lossis kev poob siab, feem ntau ntsuas los ntawm Charpy V-notch (CVN) kev ntsuam xyuas.
Nyob rau hauv cov xwm txheej annealed, Ti‑6Al-4V nthuav tawm zoo heev chav-kub qhov cuam tshuam toughness, nrog Charpy feem cuam tshuam lub zog muaj nuj nqis xws li 25 txog 40 J rau cov qauv qauv. Cov qib ntawm qhov toughness no tso cai rau cov hlau tuaj yeem tiv taus cov loads tam sim ntawd, kev vibrations, thiab kev cuam tshuam me me yam tsis muaj kev puas tsuaj, ua rau nws tsim nyog rau cov khoom siv hluav taws xob xws li dav hlau tsaws iav qhov chaw, fasteners, thiab cov khoom siv hauv hiav txwv.
Txawm li cas los xij, tus cwj pwm cuam tshuam yog qhov nkag siab zoo rau kev kho cua sov thiab microstructure.
Nyob rau hauv cov tshuaj kho thiab hnub nyoog (STA) mob, txawm hais tias lub zog thiab hardness nce, cuam tshuam toughness txo me ntsis, feem ntau ntawm 15 mus rau 25 J. Qhov kev txo qis no yog vim nag lossis daus ntawm nplua alpha theem hauv beta matrix, uas ua rau kom muaj zog tab sis txo ductility. Notches, defects nto, thiab thickness kuj cuam tshuam rau kev ua tau zoo. Cov ntu tuab lossis cov khoom sib xyaw nrog cov ntiv taw ntse qhia qhov cuam tshuam qis zog, thaum cov khoom siv du, nyias-gauge tuav zoo dua toughness. Zuag qhia tag nrho, Ti‑6Al-4V qhia tau hais tias muaj kev tiv thaiv zoo rau kev cuam tshuam tsis zoo piv rau ntau lub zog steel thiab aluminium alloys ntawm qhov sib xws.
Thib ob, hais txog kev ua haujlwm kub ntev ntev thiab lub zog degradation, Ti‑6Al-4V feem ntau pom zoo siv rau qhov kub txog li 300℃txog 350℃rau lub sijhawm ntev.
Thaum kub qis dua 200 degree, cov alloy qhia me ntsis lub zog degradation txawm tias tom qab ntau txhiab teev raug. Tensile thiab creep zog nyob ruaj khov, tsis muaj qhov tseem ceeb microstructural coarsening lossis softening.
Thaum raug kub ntawm 200℃thiab 300 degree, me ntsis thermal stability tshwm sim dhau sijhawm. Cov alloy muaj kev cuam tshuam me me alpha-phase coarsening thiab residual kev ntxhov siab so, ua rau txo qis hauv tensile thiab yield zog -feem ntau tsawg dua 10% tom qab kev laus mus ntev. Qhov kev txo qis no yog siv tau rau feem ntau cov ntawv thov tsis yog aerospace.
Tshaj 350℃mus rau 400 degree, lub zog tseem ceeb degradation tshwm sim nyob rau hauv kev pabcuam ntev.
Accelerated microstructural hloov, nrog rau alpha grain loj hlob thiab beta theem decomposition, txo ob creep kuj thiab tensile zog. Lub zog poob tuaj yeem ncav cuag 15% mus rau 30% lossis ntau dua, nyob ntawm lub sijhawm raug thiab kub. Yog li ntawd, Ti‑6Al-4V tsis pom zoo rau kev siv mus sij hawm ntev, kev ntxhov siab siab tshaj 350 degree.
Hauv cov ntsiab lus, Qib 5 titanium alloy qhia tau zoo rau kev cuam tshuam zoo heev ntawm chav tsev kub, nyob ntawm kev kho cua sov thiab geometry.Nws tswj cov khoom ruaj khov nrog lub zog tsawg tsawg ntawm qhov kub txog 200 degree, thiab tsuas yog poob qis dua 300 degree. Tshaj 350 degree, kev pab cuam mus sij hawm ntev ua rau pom kev muag muag thiab txo lub peev xwm nqa. Qhov kev sib xyaw ua ke ntawm kev cuam tshuam rau qhov hnyav thiab qhov nruab nrab thermal stability ua rau Ti-6Al-4V ib qho kev xaiv txhim khu kev qha rau cov khoom siv uas raug rau cov khoom hnyav thiab qhov kub thiab txias.
