Temperature Dependence of Slip-Twinning Mechanism in AZ31 Magnesium Alloy under High Strain Rate Compression: Experimental and Molecular Dynamics Study
摘要
The competition between the deformation mechanisms of twinning and slip is a core factor that determines the plastic behavior and microstructure evolution of magnesium alloys. In this work, high-speed impact experiments of AZ31 alloy along the extrusion direction (ED) were performed using split Hopkinson pressure bar (SHPB) at the strain rate of 1300 s−1 and temperatures ranging from room temperature (RT) to 300 ℃. The deformation mechanisms of AZ31 alloy were characterized by electron backscatter diffraction (EBSD) and transmission electron microscopy (TEM), while molecular dynamics (MD) simulation was used to observe the transformation of deformation mechanisms and crystal structures during the impact process. The experimental results indicate that with the increasing of temperature, the peak stress of AZ31 alloy decreases, At RT and 100 °C, the deformation is primarily dominated by basal slip and tensile twinning. While at 300 °C, basal slip and pyramidal