Effect of differential temperature on the interfacial microstructure evolution and mechanical properties of asymmetrically rolled Mg/Al composite plates

Abstract

To investigate the effects of differential temperature on microstructure, interfacial morphology and mechanical properties of Mg/Al composite plates, asymmetric rolling was used to prepare Mg/Al composite plates. The results show that the shear deformation induced slip system at interface is less and the degree of dislocation accumulation is higher in isothermal rolling compared to differential temperature rolling. This results in a higher degree of subgrain in each layer and higher tensile and yield strength of composite plate. However, the plate is prone to stress concentration at interface, which severely reduces elongation and bond strength. The differential temperature rolling can better promote the recrystallization of magnesium alloy and grain refinement of aluminum alloy at interface by introducing temperature gradient. This reduces the occurrence of stress concentrations at interface, resulting in higher elongation and bond strength of composite plate.