A high-performance Mg-Er-Zn-Zr alloy with low Er/Zn mass ratio

The microstructure and properties of a quarternary Mg-8Er-5Zn-0.5Zr(mass fraction, %) alloy with the low Er/Zn mass ratio of 1.60 were investigated. It is found that despite of the low Er/Zn mass ratio, the microstructure of the as-prepared alloy is composed of α-Mg, W phase with face-centered cubic structure and long packed stacking ordered(LPSO) phase. As expected, the extruded and annealed alloy possesses high yield stress(310 MPa) and good elongation(14%) at room temperature. The superior mechanical properties can be interpreted in terms of the promising microstructure characteristic of fine α-Mg recrystallized grains embedded with high-density fine lamellar-shaped LPSO phase and block W phase structure.