【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)300℃→β+α600℃→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)300℃→β+α+等温ω600℃→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。更多还原

【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 asβ+α″(ST) 300℃→β+α600℃→β+α+isothermalωfor the former,andβ+α″+quenchedω(ST) 300℃→β+α+isothermal ω600℃→β+αfor the latter.The addition of Ta to the Ti-Nb-Zr alloy system can suppress the formation of quenchedω phase during the solution treatment and increase the precipitation temperature of the isothermalωphase during subsequent aging treatments.更多还原