粗大晶粒TA2纯钛的准静态拉伸行为及其机制  

Quasi-Static Tensile Behavior and Relevant Mechanisms of Coarse-Grained TA2 Pure Titanium

作　　者：石晓辉 曹祖涵 范智渊 郭瑞鹏 乔珺威[1] Shi Xiaohui;Cao Zuhan;Fan Zhiyuan;Guo Ruipeng;Qiao Junwei(Taiyuan University of Technology,Taiyuan 030024,China)

机构地区：[1]太原理工大学,山西太原030024

出　　处：《稀有金属材料与工程》2021年第7期2536-2540,共5页Rare Metal Materials and Engineering

基　　金：国家自然科学基金(51801132)。

摘　　要：采用OM、SEM、EBSD等方法对41、63、323μm3种晶粒尺寸TA2纯钛的准静态拉伸行为及其机制进行研究。结果表明:晶粒粗化导致TA2具有更高的均匀变形能力。究其原因,晶粒尺寸越大,变形时孪晶活性越强。孪晶界起到分割晶粒的作用,可减少位错有效滑移距离,阻碍位错运动,故对材料的整体应变硬化率起到正向作用。当晶粒尺寸由41μm增至323μm左右时,应变硬化率曲线可由持续降低趋势转变为降-升-降3阶段变化趋势。粗大晶粒中孪晶所引发的高应变硬化率是TA2呈现高均匀变形能力的根本原因。The quasi-static tensile behavior and mechanism of TA2 pure titanium with three grain sizes of 4 1, 63, and 323 μm were studied using OM, SEM, EBSD, etc. The results show that the coarsening of the grains results in a higher uniform deformability of TA2. The reason is that the larger the grain size, the stronger the twinning activity during deformation. The twin boundaries divid e the grains and reduce the effective sliding distance and hinder the movement of dislocations, so it has a positive effect on the strain hardening rate of the material. When the grain size increases from 41 μm to about 323 μm, the strain hardening rate curve changes from a continuous decreasing trend to a three-stage change trend of decreasing-increasing-decreasing. The high strain hardening rate induced by twins in the coarse grains is the root cause of TA2’s high uniform deformability.

关 键 词：TA2 晶粒尺寸 应变速率 拉伸 孪晶 

分 类 号：TG146.23[一般工业技术—材料科学与工程]