1. Oxidation Resistance ntawm Qib 5 Titanium Alloy ntawm Kub Kub
Qib 5 titanium alloy pom zoo oxidation tsis kam ntawm nruab nrab kub, tab sis nws qhov kev ua tau zoo yog qhov kub thiab txias.
Thaum kub txog 300℃- 350 degree, cov hlau ua ib txheej nyias, ntom, thiab adherent oxide txheej tsuas yog tsim los ntawm TiO₂. Cov txheej tiv thaiv no tiv thaiv cov pa oxygen ntxiv mus rau hauv lub substrate, ua rau qeeb oxidation kinetics thiab kev ua haujlwm ruaj khov thaum lub sijhawm ua haujlwm ntev.
Thaum qhov kub siab tshaj 400 degree, oxidation accelerates noticeably. Cov txheej oxide ua tuab dua, tsis sib xws, thiab tuaj yeem poob adhesion, ua rau muaj cov pa oxygen ntau ntxiv hauv titanium matrix. Tshaj li 450℃- 500 degree, oxygen nkag mus rau oxygen embrittlement: oxygen atoms dissolve interstitially nyob rau hauv titanium lattice, nce hardness tab sis heev txo ductility thiab cuam tshuam toughness. Qhov no tshwm sim yog hu ua interstitial embrittlement.
Yog li, Qib 5 tsis pom zoo rau kev siv txuas ntxiv saum 400℃yog tias yuav tsum muaj kev ncaj ncees thiab ductility. Rau cov ntawv thov siab tshaj 400 degree, oxidation-resistant coatings los yog siab dua-kub titanium alloys xws li IMI 834 los yog Ti-6242 yog nyiam.
2. Kev Pabcuam Sijhawm Ntev: Lub zog thiab Corrosion Resistance Degradation
(1) Lub Sij Hawm Lub Sij Hawm Lub Zog Degradation
Thaum lub sij hawm ntev-kub raug, Qib 5 titanium alloy muaj kev hloov pauv microstructural uas cuam tshuam rau cov khoom siv kho tshuab.
Nyob rau hauv thaj tsam ntawm 300℃- 350 degree, tensile lub zog thiab lub zog tawm los tseem nyob ruaj khov rau ntau txhiab teev.
Kev tuav ntev ntawm 400℃- 550℃ua rau alpha theem coarsening thiab thermal so, ua rau maj mam txo qis zog tensile thiab qaug zog.
Oxygen diffusion thiab interstitial embrittlement ntxiv txo ductility thiab tawg toughness.
Rau kev ua haujlwm ntev ntev, kev lag luam feem ntau lees txais qhov kev pabcuam txuas mus ntxiv ntawm 315℃rau Qib 5. Tshaj li qhov kub thiab txias, lub zog degradation ua qhov tseem ceeb thiab txwv kev tiv thaiv lub neej.
(2) Lub Sij Hawm Corrosion Resistance
Nyob rau hauv feem ntau ib puag ncig, suav nrog marine, nruab nrab cua, thiab tshuaj lom neeg me me, Qib 5 tswj kev tiv thaiv corrosion zoo tom qab siv mus ntev.
Cov txheej tiv thaiv TiO₂ spontaneously hloov kho yog puas, muab kev tiv thaiv corrosion tsis tu ncua.
Txawm li cas los xij, ob yam tuaj yeem txo qis kev ua haujlwm:
Kub-kub oxidation embrittlement:Raws li tau hais, kev nkag mus rau oxygen sib sib zog nqus degrades nto toughness thiab tuaj yeem txhawb kev tawg tsim nyob rau hauv kev ntxhov siab.
Creep-corrosion sib cuam tshuam:Nyob rau hauv qhov kub thiab txias thiab kev ntxhov siab, creep deformation yuav rupture lub passive zaj duab xis hauv zos, accelerating localized corrosion nyob rau hauv aggressive media.
Nyob rau hauv cov kev pabcuam ib txwm muaj qis dua 300 degree, tsis muaj qhov cuam tshuam zoo hauv kev tiv thaiv corrosion tshwm sim nyob rau lub sijhawm ntev.
Cov ntsiab lus
Qib 5 titanium alloy muaj kev txaus siab oxidation tsis kam mus txog 350℃- 400 degree. Tshaj li 400 degree, oxidation thiab oxygen embrittlement ua limiting yam.
Lub sij hawm ntev ntawm qhov kub thiab txias yuav ua rau txo qis zog vim microstructural coarsening thiab interstitial embrittlement, thaum corrosion kuj tseem ruaj khov nyob rau hauv ib puag ncig kev pab cuam. Rau kev ntseeg siab tshaj plaws, kev ua haujlwm tsis tu ncua yuav tsum raug txwv rau kwv yees li 315 degree.
