机械合金化制备纳米晶Ti-6Al-4V合金

Preparation of Nanocrystalline Ti-6Al-4V Alloy by Mechanical Alloying

采用机械合金化制备Ti-6Al-4V粉末。结果表明:采用机械合金化可以制备纳米晶Ti-6Al-4V合金粉,其反应机理以扩散为主,该固态反应是缺陷能和碰撞能共同作用的结果;随球磨时间延长,部分V固溶于Ti中形成置换固溶体Ti(V),球磨过程中没有中间相生成。球磨40 h后都能获得纳米晶,60 h的粉末为纳米晶和非晶的混合物,晶粒尺寸小于60 nm;60 h后晶粒尺寸变化缓慢。球磨后Ti、Al、V的原子比近似为90:6:4,与Ti-6Al-4V元素成分一致。

Ti-6Al-4V alloy powder was prepared by mechanical alloying. The alloying mechanism and the relationship of alloyed products to processes were investigated. The results show that mechanical alloying can prepare nanocrystalline Ti-6Al-4V alloy powder. The reaction mechanism is dominated by diffusion, and the solid-state reaction is the interaction result of defects energy and collision energy. With increasing the milling time, substitution solid solution Ti（V） is formed in the process, without intermediate phase generated in the milling process. Milling for 40 h can produce nanocrystalline, while milling for 60 h can obtain nanocrystalline and polycrystalline mixtures with the grain sizes less than 60 nm. However, little change in grain size occurs with further milling after 60 h. After milling, the atomic ratio of Ti, Al, V approximates to 90：6：4, which is consistent with the elemental composition of Ti-6Al-4V.