Twin characteristics and flow stress evolution in extruded magnesium alloy AZ31 subjected to multiple loads

The twin characteristics and flow stress evolution in the extruded magnesium alloy AZ31 under prior compression parallel to extrusion direction (ED) and then compression perpendicular to ED at room temperature was investigated. Because of the role of activated basal slip, samples parallel to the extrusion radial direction exhibit lower yield stress than these parallel to the ED. However, the compressive yield stress of the sample parallel to the extrusion radial direction increases when there is pre-compression along ED. Twins produced under the load parallel to ED are nearly parallel to each other in a grain, but the twin morphologies are multiple in the sample parallel to extrusion radial direction. Schmid factor was conducted to explain the twin characteristics and flow stress evolution under these stress condition.