High-strength wrought magnesium alloy with dense nano-scale spherical precipitate

This paper reported the influences of Yb addition on the precipitate and mechanical properties of wrought magnesium alloy ZK60. The ingots of ZK60-1.78Yb (wt%, 0.26 at%) alloys were cast using permanent mould and extruded at 370 degrees C. By means of TEM and HRTEM, it was observed that Yb affected the precipitate and precipitation of ZK60-1.78Yb alloys significantly. Dynamic precipitation occurred in the as-extruded alloy and spherical nano-scale precipitate with high density and homogeneity exhibited in the aged alloys. The precipitate particles were about 5-20 nm in diameter, 10-30 nm in average space length. The tensile test results showed that the ZK60-1.78Yb alloy had excellent precipitation strengthening response with the maximum tensile strength 417.5 MPa at ambient temperature.