Forming characteristics of AZ31B magnesium alloy in bidirectional extrusion process

This study investigated the forming characteristics of magnesium alloy (AZ31B) in bidirectional extrusion. Simultaneous forward–backward extrusion, which is frequently performed in industrial production, is conducted. The effect of process parameters such as forward extrusion ratio, backward extrusion ratio, and working temperatures were also examined. A high precision forging of the alloy was achieved under warm condition. A forming limit of the alloy in the combined process was found by parametric study. The deformation of the material appears to be localized, and the intrinsic limited formability of the alloy resulted in cracks on the extruded surface. We found that crack is initiated and developed easily under the low static pressure.