剧烈塑性变形条件下工业纯钛晶粒细化机理研究

Study on Grain Refinement Mechanism for Commercial Pure Titanium Processed by Severe Plastic Deformation

通过对工业纯钛表面机械研磨(SMAT)这种变形方式的结果和微观组织变化的研究,分析了工业纯钛的晶粒细化机制,讨论了其他剧烈塑性变形技术无法制备出晶粒尺寸更小的纳米晶的原因。结果表明:对于工业纯钛,SMAT这种具有高的应变速率和多方向载荷的变形方式,有利于形成细小的纳米晶;同时高应变速率增加了位错滑移的临界分切应力。

The outcome and microstructure change of commercial pure titanium （CP-Ti） processed by surface mechanical attrition （SMAT） were analyzed. The grain refinement mechanism of SMAT CP-Ti was systematically investigated by means of transmission electron microscopy. The reason that other severe plastic deformation （SPD） can not obtain finer nano-crystalline was discussed. The experimental results show that the high-strain-rate and many direction loading are conductive to the formation of nano-grains, and the high-strain-rate goes against dislocation slipping.