Effect of extrusion on damping and mechanical properties of Mg-Zn-Y alloy

Abstract The damping and mechanical properties of extruded Mg-Zn X -Y 1.33X (X = 1, 2, 3 at%) alloys were investigated in this experiment. The results shown that the alloy was mainly composed by long-period stacking ordered (LPSO) phase and magnesium(Mg) matrix. With the increase of Zinc(Zn) and Yttrium(Y) content, the grains had a certain refinement, the LPSO content was significantly increased, accompanied by a small amount of rare Y-enriched particles. After extrusion, the second phase of the alloys were broken into small pieces. The tensile strength(UTS) and yield strength(YS) of the alloy increased significantly, but the elongation decreased with the increase of LPSO phase. Mg-4.9Zn-8.9Y shown the best mechanical properties, with the tensile strength of 415 MPa, yield strength of 325MPpa, and elongation of 6.5%. Research on alloy damping performance shown that as the content of LPSO increases, the damping performance of as-cast alloys increased, and there is no obvious change after extrusion. It was due to a large number of dislocations entangled with work hardening, which greatly reduced the dislocation damping in magnesium alloys.