通过组织观察以及宏观和微观织构测定、分析了异步轧制及等径角轧制的AZ31镁合金形变机制,确定了在这两种工艺下{0001}基面织构的改善效果.结果表明:异步轧制产生的平行于轧面的剪切力促进了与普通轧制状态下相反的基面滑移,使基面织构连续地弱化为倾转的基面织构;而等径角轧制通过产生与轧向成122.5°的剪切力,使基面取向的晶粒产生拉伸孪晶,形成与基面织构共存的柱面织构.因此这两种特殊工艺都可能改善镁合金的塑性.还分析了形变量和退火对织构的影响.
The modifications of basal texture in AZ31 magnesium alloys processed by asym- metrical rolling and equal channel angular rolling (ECAR) are investigated. Deformation mechanisms are determined by microstructure observation and macro and micro-texture measurements. Results show that during asymmetrical rolling the basal texture is gradually rotated around TD (transverse direction) by basal slip activated by shear strain on the rolling plane, whereas the prism texture is induced by tension twinning activated by shearing parallel to the plane separating the two channels during ECAR. So both the special processing techniques may improve the plasticity of magnesium alloy. The effects of rolling reduction and annealing on textures are also studied and discussed.