(北京工业大学 固体微结构与性能研究所,北京 100124)
摘 要: 采用显微硬度测试、X射线衍射分析和透射电子显微镜观察等方法,研究不同热处理后生物医用Ti-35Nb-5Ta-7Zr合金和Ti-35Nb-7Zr合金的显微硬度变化及微观组织特征,揭示Ta元素的添加对合金微观结构、时效析出序列及性能的影响。结果表明:Ti-35Nb-5Ta-7Zr合金比Ti-35Nb-7Zr合金具有更明显的时效强化效果;固溶处理(ST)后经300和600 ℃时效处理,Ti-35Nb-5Ta-7Zr合金的时效析出顺序可以描述为β+α″(ST) β+α β+α+等温ω,而Ti-35Nb-7Zr合金的时效析出顺序为β+α″+淬火ω(ST) β+α+等温ω β+α;Ta元素的添加抑制固溶处理过程中淬火ω相的析出,提高时效过程中等温ω相的析出温度。
附件:25-p1195-14681
关键字: 生物医用材料;医用钛合金;Ti-35Nb-5Ta-7Zr合金;Ti-35Nb-7Zr合金;时效;微观结构;显微硬度
中图法分类号:TG 146
(Institute of Microstructure and Property of Advanced Materials, Beijing University of Technology, Beijing 100124, China)
Abstract:The variations of microhardness and microstructures for the biomedical Ti-35Nb-5Ta-7Zr and Ti-35Nb-7Zr alloys subjected to different heat treatments were studied by microhardness test, X-ray diffractometry and transmission electron microscopy. The effects of alloying element Ta on these variations and aging precipitation sequences were revealed. The results show that the aging strengthening effect in the Ti-35Nb-5Ta-7Zr alloy is more prominent than that in the Ti-35Nb-7Zr alloy. For the solution-treated Ti-35Nb-5Ta-7Zr and Ti-35Nb-7Zr alloys (in ST state), the precipitation sequences during subsequent aging treatments at 300 and 600 ℃ can be described as β+α″(ST) β+α β+α+isothermal ω for the former, and β+α″+quenched ω(ST) β+α+isothermal ω β+α for the latter. The addition of Ta to the Ti-Nb-Zr alloy system can suppress the formation of quenched ω phase during the solution treatment and increase the precipitation temperature of the isothermal ω phase during subsequent aging treatments.
Key words: biomedical materials; biomedical titanium alloys; Ti-35N6-5Ta-7Zr alloy; Ti-35Nb-7Zr alloy; aging; microstructure; microhardness