Mechanical properties and forming behavior of extruded AZ31 and ME21 magnesium alloy sheets

A comparative analysis of mechanical properties and forming behavior of extruded sheets of AZ31 and ME21 magnesium alloys is presented. The mechanical properties were determined by tensile tests in different loading directions and the forming behavior was investigated by hot deep drawing tests. Both magnesium sheets exhibit a mechanical anisotropy due to the directional activation of deformation mechanism with the anisotropy in sheet plane more pronounced for the ME21 than for the AZ31 sheets. As expected, increasing the testing temperature reduces both the mechanical strength and the mechanical anisotropy in the sheet plane improving the elongation to failure. While for the AZ31 sheets the r-values remain constant with increasing temperature, the r-values for the ME21 sheets show an increase in the range of 20 °C≤T≤200 °C followed by a decrease in the range 200 °C≤T≤300 °C. Both magnesium sheet alloys exhibited qualitatively similar deep drawing characteristics depending on temperature. The differences in drawability of both magnesium sheets are mainly attributed to the different activities of softening mechanisms.