Damping behavior and mechanical properties of Mg-Cu-Mn alloy processed by equal channel angular pressing

Equal channel angular pressing(ECAP)WaS conducted at 250℃ for 4 passes to the as-extruded Mg-3%Cu-1%Mn alloy with high strength and high damping capacity.After ECAP processing,the grain of as-extruded alloy is significantly refined to about 4 μm,both yield strength and tensile strength of the as-extruded Mg-Cu-Mn alloy are decreased,but the ductility is impmved.After the ECAP processing,the damping capacity of Mg-Cu-Mn alloy is decreased at room temperature,while is substantially increased at elevated temperatures,After annealing at 300℃ for 1h,both yield strength and tensile strength of the ECAPed alloy are further decreased,but the ductility is significantly improved.The damping capacity of the as-annealed alloy is increased at room temperature,while is decreased at elevated temperatures.The mechanisms for damping capacity of the alloy at ambient and elevated temperatures wore discussed.