Study on the Constitutive Behavior and Hot Deformation Characteristic of Mg-4Sm-2Zn-0.5Zr Alloy

Mg-4Sm-2Zn-0.5Zr alloy is a new type of heat-resistant magnesium alloy, it has the mechanical properties similar to EZ33 alloy but is much cheaper than EZ33 in cost since Samarium (Sm) rather than Nd was employed in the alloy. In this paper, based on isothermal compression tests in the temperature range of 350-450 degrees C and strain rate range of 0.001-1.0s(-1), the Arrhenius-type constitutive equations for this alloy were established, and the hot working flow behavior and the microstructures of the alloy were examined. To evaluate the hot deformation mechanisms and determine the optimal processing parameters, 3D processing maps under different deformation conditions were developed according to the dynamic material model and Muthy instability criterion. The hot extrusion experiments were carried out, and the results show the predictions of processing maps are in agreement with the experimental results.