Study on high speed impact deformation behaviors of Mg-1Al-4Y by SHPB

Abstract

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.