中文摘要：

本文采用原位背散射电子衍射（原位-EBSD）方法研究了AZ31合金在压缩应力下的微观组织演变。结果表明{10 12}[1011]孪生是主要的变形模式。该孪生模式导致了变形后晶体取向发生了明显的转变,由原始取向为其C轴垂直于挤压方向ED的丝织构,转变为其C轴平行于ED及压缩应力方向。同时位错滑移也提供了一定的变形量。AZ31合金中RD和TD织构组分的梯度对于压缩变形条件下的孪生变形没有明显的影响。

英文摘要：

The microstructure evolution of extruded AZ31 alloy tube under compression was studied by in-situ electron backscatter diffraction（in-situ EBSD）.Extension twining,{1012} was the main deformation mode in the tube under compression,which leaded to the texture changing from initial basal ring fiber, perpendicular to compression direction（CD）,to //CD.The texture gradient on radial direction（RD） and tangential direction（TD） had weak effect on the twining mode.