The twin boundary damping peak and the transformation damping peak constitute the temperature dependent damping behavior in Mn-Cu alloys. In order to observe the effects of twinning microstructure on the twin boundary damping behavior, a Mn-30at%Cu alloy was finally treated by furnace cooling and aging after water-quenching. Regular twin bands with the similar widths along some {101} twin boundary were observed in the furnace-cooled condition, while intersected twin bands with pointed fronts belonging to different {101} twin boundaries occurred in the water-quenched specimens. Meanwhile, the twin boundary damping features were obtained based upon dynamic mechanical analyzer measurements, and increased activation energy and decreased peak damping capacity were found in the treated alloy. The distortion state of the interfaces enclosing the decomposed nm-regions was considered to influence the twinning microstructure formation and hence altered the damping features of the twining microstructure.

The Twinning Microstructure and Damping Behavior in Mn-30at%Cu Alloy. F.Yin, T.Sakaguchi, Q.Tian, A.Sakurai, K.Nagai: Materials Transactions, 2005, 46[10], 2164-8