Preparation and properties of Mg–Cu–Mn–Zn–Y damping magnesium alloy

This paper presents the successful preparation of a high-damping, high-strength Mg–Cu–Mn–Zn–Y alloy by alloying and extrusion. The damping capacity of the as-cast Mg–3Cu–1Mn alloy (alloy 1) displayed evident variations with changes in Y and Zn content. The as-cast Mg–3Cu–1Mn–2Zn–1Y alloy (alloy 2) exhibited excellent damping capacity and unusual damping growth in the high-strain amplitude stage; the damping capacity of alloy 2 exceeded that of alloy 1 and even approached that of pure Mg when the strain amplitude exceeded 5 × 10−4. This observation is believed to be related to the formation of long and parallel dislocation configurations and the interactions between these dislocations and plastic second-phase particles. The study also showed a remarkable improvement in the mechanical properties of as-extruded Mg–Cu–Mn–Zn–Y alloys. We attribute this finding to dynamic recrystallization, dispersion strengthening, and work hardening during hot extrusion.

► A novel high-damping, high-strength Mg–Cu–Mn–Zn–Y alloy was successfully prepared by alloying and extrusion. ► The damping capacity of Mg–Cu–Mn–Zn–Y alloys was discussed by Granato–Lücke theory. The as-cast Mg–3Cu–1Mn–2Zn–1Y (wt.%) alloy exhibited excellent damping capacity and unusual damping growth in the high-strain amplitude stage. ► This observation is believed to be related to the formation of long and parallel dislocation configurations and the interactions between these dislocations and plastic second-phase particles, and the TEM image gives the direct evidence. ► The remarkable improvement in the mechanical properties of Mg–Cu–Mn–Zn–Y alloys was obtained by extrusion process, the reason for which was discussed in detail.