Effects of training temperature on damping capacity in thermally cycled Fe–20 mass%Mn alloy

Influences of training-treatment processes on damping capacity and microstructure of Fe–20 mass%Mn alloy have been investigated. The training method in this study is thermal cycling. As processing parameters of the training treatment, the number of training cycles and the training temperature are varied. Internal friction is measured at room temperature using a free-decay method. The ɛ-martensite phase, which is the damping source of Fe–Mn alloys, is refined as the number of training cycles increases. Because of this structural evolution, both damping capacity and hardness of the Fe–Mn alloy are improved by thermal training. This method to improve damping capacity and hardness is a novel point in our study. Moreover, in order to find an optimum training condition for the improvement of the damping capacity, the effects of the training temperature have been investigated. From the obtained results, the optimum condition for the improvement of the damping capacity is proposed.