Microstructures and Mechanical Properties of Mg-5Yb-0.5Zr Wrought Magnesium Alloy

Mg-5Yb-0.5Zr ingots were prepared by using flux melt protection method and then hot extruded and heat treated.The phase constitution,microstructure and mechanical properties of the alloy at various processing conditions were studied.Experimental results show that the alloy was composed by α-Mg and Mg_2Yb phases.Mg_2Yb intermetallics was congregated at grain boundaries at as-cast state and broken during extrusion process,which had the effects of restricting dynamic recrystallization and dispersion strengthening.Aging strengthening response of the alloy in T5 and T6 conditions was disclosed,and the precipitate was fine conjugated short rod-like particles.The as-extruded alloy had maximum tensile property,and the optimal mechanical property was obtained at T5 heat treatment state.