(西北有色金属研究院,西安 710016)
摘 要: 研究固溶和时效热处理对近β型医用Ti-15Nb-5Zr-6Mo合金的组织与力学性能的影响。结果表明:固溶温度的升高使得β晶粒尺寸增大,但是对性能的影响不大,合金表现出较高的强度及良好的塑性。然而较高的屈强比以及塑性硬化阶段的缺失,使其应用受到局限。时效处理引入的α相强化使得合金强度提高到1 000 MPa以上,塑性提高到15%~20%;同时,塑性阶段出现应力平台,表现为稳态塑性变形。因此,通过合理的热处理工艺可以在保证合金高强度的同时提高塑性。
关键字: Ti-15Nb-5Zr-6Mo合金;固溶处理;时效处理;相转变;力学性能
(Northwest Institute for Nonferrous Metal Research, Xi’ an 710016, China)
Abstract:The effects of solution treatment and aging on microstructure and mechanical properties of near β Ti-15Nb-5Zr-6Mo alloy developed for biomedical application were investigated. The results show that the increase in solution temperature results in an increased β grain size, while shows no obvious influence on the mechanical properties. The solution-treated alloy exhibits high strength and good ductility. However, the properties matching is limited in actual application due to its high ratio of yield to ultimate strength and the lack of hardening stage during plastic deformation. The precipitation of α phase during aging treatment leads to a great strength of above 1 000 MPa and good ductility with elongation of 15%-20%. Additionally, a stress flat is observed, exhibiting stable plastic deformation. Therefore, the strength and ductility of Ti-15Nb-5Zr-6Mo alloy can be improved simultaneously by a reasonable heat treatment.
Key words: Ti-15Nb-5Zr-6Mo alloy; solution treatment; aging treatment; phase transformation; mechanical properties