热挤压AZ31镁合金单向压缩变形的应变硬化行为

发布时间：2018-03-14 11:20

  本文选题：AZ镁合金　切入点：拉伸孪生　出处：《中国有色金属学报》2015年05期 　论文类型：期刊论文

【摘要】：对AZ31镁合金热挤压棒材在室温下沿挤压方向分别进行了应变为3%、6%、10%的单向压缩实验。利用OM、XRD和EBSD等技术研究了不同压缩应变量下的显微组织、织构及应变硬化的演变特征。结果表明:具有{0002}纤维织构的热挤压态AZ31镁合金沿着挤出方向压缩时,产生显著的应变硬化效应。其塑性变形可大致分为3个阶段:初始阶段主要发生{1012}拉伸孪生,表现为较低的应变硬化速率和应变硬化速率的急剧减小;随着压缩应变量的增加,孪晶界逐渐扩展,直至部分晶粒发生完全孪生,基面织构强度逐渐增强;拉伸孪晶生长所造成的强{0002}基面织构是产生高应变硬化速率的主要原因;应变硬化速率第Ⅱ~Ⅲ阶段的转折点大致与拉伸孪晶的生长停滞相对应。
[Abstract]:Unidirectional compression experiments of AZ31 magnesium alloy hot extruded bar with strain of 3% and 10% along extrusion direction were carried out at room temperature. The microstructure of hot extruded bar under different compression strain was studied by OMXRD and EBSD techniques. The evolution of texture and strain hardening. The results show that the hot extruded AZ31 magnesium alloy with {0002} fiber texture is compressed along the extrusion direction. The plastic deformation can be divided into three stages: at the initial stage, {1012} tensile twinning mainly occurs, which shows that the lower strain hardening rate and strain hardening rate decrease sharply, and with the increase of compression strain, The twinning boundary gradually expands until some of the grains are completely twinned and the basic texture strength increases gradually, and the strong {0002} basal texture caused by the tensile twin growth is the main reason for the high strain hardening rate. The turning point of strain hardening rate stage 鈪，

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