Tensile Properties of Mg-8Al-xRE Alloys from 300 K to 673 K

摘要

This paper presents the tensile properties of cast and extruded Mg-8Al-xRE (in mass percent; x is 0, 1, 2 or 3 percent) alloys from 300 to 673K obtained at a strain rate of 8.3 X 10~(-4) s~(-1) Mg-8Al-xRE alloys were prepared by melting and casting in a vacuum induction furnace, and extruded at 633 K with a reduction ratio of 90:1. RE greatly improves the tensile strength of cast and extruded Mg8Al alloys above 473 K. RE negatively affects the elongation of cast alloys at the studied temperature range but considerably enhances 'hat of extruded alloys. Superplasticity of the extruded alloys is observed at 473 K or above. The strengthening mechanisms and the optimal deformation temperature, T_c, of these alloys are discussed in detail.