The strengthening effect of spinodal decomposition and twinning structure in MnCu-based alloy

The strengthening effects of spinodal and twining structures in Mn–20 at%Cu–5 at%Ni–2 at%Fe (M2052) alloy are investigated. In order to distinguish the respective roles in the strengthening of the alloy played by grain size, spinodal structure and twin structure, the M2052 alloys are solution heat treated at different temperatures, followed by an aging treatment for a different duration of time. The results show that the alloy exhibits a high strengthening effect after the aging treatment, which can be ascribed to the substructures of spinodal and twin structures formed during the aging process. The strengthening effect of spinodal structure and twin structure increases with the increase in aging time. However, the strengthening effect of spinodal structures is about 3 times which is caused by twin structures. In addition, the twin strengthening effect (twin density) shows grain-size dependence, while the spinodal strengthening effect does not.