The phase stability and elastic properties of MgZn2 and Mg4Zn7 in Mg–Zn alloys

To understand the precipitates in Mg–Zn alloys, we perform first-principles calculations to investigate the stability and elastic properties of Laves MgZn2 and monoclinic Mg4Zn7. We find that the relative stability of MgZn2 and Mg4Zn7 is dependent on their compositions, implying that either one or both of the phases can exist within β1′ precipitates. The elastic moduli indicate that the strain resistance of MgZn2 and Mg4Zn7 is much greater than that of Mg.