Structure and Mechanical Properties of Mg-Zn-Mn Alloys Doped with Y Elements

Abstract

Quaternary alloys with nominal components Mg-2Zn-0.3Mn-xY wt.% (x=0, 1, 2) were prepared by melting method. The structure and mechanical properties of as-cast, as-extruded and T6 heat-treated alloys were studied. The results show that the phases of as-cast alloys are mainly É‘-Mg matrix, with a small amount of MgZn2 and Mg3Y2Zn3 second phases. The addition of Y could refine the grains. After hot extrusion and T6 heat treatment, the grains were refined, and more second phases precipitated in the alloys. In the samples with same composition, the yield strength and tensile strength of the alloys increased with the order of as-cast, extrusion and T6 heat treatment, and the elongation decreased. For samples with different yttrium content, the higher the yttrium content, the higher the tensile strength and yield strength.