Microstructure and Damping Capacity of a Mn35Cu60Al3Fe2 Alloy by Semisolid Heat Treatment

A 35Mn-60Cu-3Al-2Fe (at%) alloy was prepared by vacuum induction melting followed by hot forging at 1073 K, and then heat treated at 1113K for 5 h. Further, the alloy was semisolid heat treated at 1153, 1163, 1173 and 1183K for 20 min. The microstructure and damping capacity of the alloys at different temperatures have been investigated comparatively. The results show that the microstructure of the alloy at 1113K comprises single phase while that at 1153-1183K consists of Mn-rich and Mn-poor phases. The area fraction of Mn-rich phase raises with increase in semisolid treatment temperature. The damping capacity of the alloy is lowest at 1113K and raises with increasing the semisolid treatment temperature (1153-1183 K) due to gradually increased amount of Mn-rich phase.