Deformation and fracture behavior of hot extruded Mg alloys AZ31

Grains inside extruded Mg alloys AZ31 are usually elongated along the < 112̄0 > crystal direction with their c axis perpendicular to extrusion direction, which often affects mechanical properties of the AZ31 alloys significantly. Here, we conduct cold compressive and tensile deformation tests to the as-extruded AZ31 alloys, aimed at investigating the role played by elongated grains in deformation and understanding the origin of fracture propagation. Using several analytic techniques, we characterize the fracture features thoroughly and identify the fracture propagation mechanism as the dimpled rupture during cold tensile deformation. We also investigate the fundamental impact of the elongated grains, twins, inclusions, and secondary phase on the crack propagation, and propose an effective way in modifying or even enhancing mechanical properties of the engineering important Mg alloys AZ31.