Microstructural adjustments and mechanical properties of a cold-rolled biomedical near β-Ti alloy sheet

作     者：Xi-Qun Ma Hong-Zhi Niu Zhen-Tao Yu Sen Yu Chang Wang 

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：0806[工学-冶金工程] 08[工学] 0805[工学-材料科学与工程（可授工学、理学学位）] 080502[工学-材料学] 0703[理学-化学] 0702[理学-物理学] 

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.