Training Effects on Damping Capacity in Mn-22.5mass%Cu-5mass%Ni-2mass%Fe Alloy

The training treatments in the shape memory alloy are known as useful method to improve the shape memory effect. In our previous study, it was shown that the training treatments can also improve both the damping capacity and the hardness of the Fe–Mn alloy. In this study, training effects on damping capacity in solution treated Mn-22.5mass%Cu-5.08mass%Ni-1.96mass%Fe alloy have been investigated. As training treatments, the thermal training (only thermal cycling) and the thermo-mechanical training (thermal cycling with deformation) are carried out. Internal friction was measured at room temperature (R. T.) using a free-decay method. Although training effect cannot be found for the samples trained at higher annealing temperature (600 ^oC and 700 ^oC), damping capacity of the alloy is improved by thermal training annealed at 400 ^oC and 500 ^oC. The trade-off between the damping capacity and mechanical properties can be overcome by the training at lower temperature.