Microstructural adjustments and mechanical properties of a cold-rolled biomedical near β-Ti alloy sheet
Microstructural adjustments and mechanical properties of a cold-rolled biomedical near β-Ti alloy sheet作者机构:Northwest Institute for Nonferrous Metal Research Xi'an 710016 China School of Materials Science and Engineering Northeastern University Shenyang 110819 China
出 版 物:《Rare Metals》 (稀有金属(英文版))
年 卷 期:2018年第37卷第10期
页 面:846-851页
核心收录:
学科分类:08[工学] 080502[工学-材料学] 0805[工学-材料科学与工程(可授工学、理学学位)]
基 金:financially supported by Industrial Science Technology Project of Shaanxi Province (No. 2015GY160) Western Metal Materials Innovation Fund (No. XBCL03-18) International Cooperation and Exchanges of State Commission of Science Technology of China (No. 2014DFA30880)
主 题:Near β-Ti alloy Microstructures Phase transformation Mechanical properties
摘 要:In this study, microstructural adjustments and mechanical properties of a cold-rolled near β-type alloy Ti-25Nb-3Zr-3Mo-2Sn (wt%) sheet were investigated. Microstructures and phase transformation products strongly depended on aging temperatures. Solution treatments within single β-phase field removed the stress-induced at martensites and produced a few new lath-shaped ones, but metastable β phase still dominated. This is exactly the reason why current alloy exhibits the lowest modulus (54 GPa) and best elongation to fracture (39 %), but the worst yield strength of only 340 MPa, at solutiontreated state. A fairly large number of ellipsoidal ω phase nanoparticles precipitated throughout parent β phase during aging at 380℃. These ω nanoparticles possess remarkable strengthening effect, but deteriorate ductility seriously. A novel post-aging process was proposed to remove brittle ω phase. By contrast, aging at 450 ℃ resulted in sufficient precipitation of fine needle-like α phase. This brought about the best combination of high yield strength (770 MPa) and moderate elastic modulus (75 GPa) and good elongation (15 %) for biomedical implants.