Impact of peak shock stress on the microstructure and reloaded mechanical behavior of AZ31 magnesium alloy

Magnesium alloys can be utilized as potential aerospace materials due to their low density, high specific strength, good vibration and shock absorption ability. This paper deals with the mechanical behavior of hot-rolled AZ31 alloy that was shock-deformed to 2.3 and 3.3 GPa. The post shock microstructure and mechanical response have been determined via full one-dimensional recovery techniques. The microstructure of deformed sample was characterized by the transmission electron microscopy (TEM) and electron back scattered diffraction (EBSD) techniques. All the shock-deformed materials showed shock-strengthening effect that was greater at higher shock pressure. The reload yield stress of the shock-deformed 2.3 GPa sample was determined to be 238 MPa while 264 MPa for the sample which shock-deformed at 3.3 GPa. It was postulated that the shock-strengthening is ascribed to a greater dislocation density and the formation of deformation twins.