High damping capacities of Mg-Cu based alloys
(1. School of Mechanical and Electronical Engineering, East China Jiaotong University, Nanchang 330013, China;
2. State Key Laboratory of Solidification Processing, Northwestern Polytechnical University, Xi’an 710072, China)
2. State Key Laboratory of Solidification Processing, Northwestern Polytechnical University, Xi’an 710072, China)
Abstract: The dynamic mechanical analyzer (DMA) was applied to investigate the damping properties of Mg-Cu based alloys. The results show that the as-cast hypoeutectic Mg-Cu binary alloys exhibit ultra-high damping capacities, while the eutectic Mg-Cu alloy exhibits low damping capacity. The strain amplitude dependent damping performance reveals that the dislocation damping mainly dominates in Mg-Cu alloys. Furthermore, the influence of eutectic phase on damping mechanisms of Mg-Cu binary alloys was discussed in detail and the effect of Si addition on the damping of Mg-1%Cu based alloy was also reported. Two damping peaks are observed on the temperature dependent spectrum of Mg-Cu based alloys. One is located at room temperature, which is dislocation related peak; and the other is located at moderate temperature, which is caused by the grain boundary sliding.
Key words: Mg-Cu based alloys; high damping; microstructure; damping peaks; damping mechanism