Capacity for Deformation and the Evaluation of Flow Stress of Hot Extruded Mg-8Al-xRE Alloys at Elevated Temperatures

Abstract

This paper investigated the optimal deformation temperature T_c, and the optimal Zener-Hollomon parameter Z_c, of both as-extruded Mg–8Al and Mg–8Al–2RE alloys, to examine the capacity of these alloys for deformation. Additionally, an equation that involves the Zener-Hollomon parameter Z was derived to evaluate the flow stress of these magnesium alloys at various temperatures and strain rates and was validated using a statistical method. These alloys were prepared by melting and casting in a vacuum induction furnace, and extruded at 633 K with a reduction ratio of 90:1. Tensile tests were performed at 473 to 723 K and at strain rates ranging from 8.3×10⁻⁴ to 8.3×10⁻¹ s⁻¹. The implications of the experimental data were discussed in detail.