This study aims to investigate the deformation behaviours of Mg-1Al-4Y alloy by SHPB apparatus under different strain rates at room temperature. Texture evolution analysis of Mg-1Al-4Y specimens were carried out by X-ray diffraction and electron back-scattered diffraction technology. The macro-texture of the specimen in the transverse direction was gradually biased towards [20–21] with the increasing of the strain rate. Furthermore, a large amount of {10–12} extension twins formed in the grains at low strain rate, and partial twin-shaped nuclei grew up to meet, resulting in formation of boundaries with ∼60 misorientation. The grain boundary orientation distribution indicated that the grain size of Mg matrix became smaller and smaller with the growth of twins, which was not conducive to the continued nucleation of twins. Meanwhile, the rotation of grains decreased the Schmid factor of the twins, which led to an obviously reduction in the fraction of the twin nucleation. Therefore, the dynamic deformation mode of Mg-1Al-4Y gradually changed from twin deformation to twin deformation and dislocation slip with the increasing of strain rate.

目的研究SHPB装置在室温下不同应变速率下Mg-1Al-4Y合金的变形行为。利用X射线衍射和电子背散射衍射技术对Mg-1Al-4Y试样进行了织构演变分析。随着应变率的增加，试样的横向宏观纹理逐渐向[20-21]方向倾斜。此外，大量的{10-12}延伸孪晶在低应变速率下在晶粒中形成，并且部分孪晶形核长大并相遇，从而形成了约60个取向错误的边界。晶界取向分布表明，随着孪晶的生长，Mg基体的晶粒尺寸越来越小，不利于孪晶的持续形核。同时，晶粒的旋转降低了孪晶的Schmid因子，从而导致孪晶形核分数的明显降低。因此，随着应变速率的增大，Mg-1Al-4Y的动态变形模式逐渐从孪生变形变为孪生变形和位错滑移。