Effects of distributions of Al, Zn and Al+Zn atoms on the strengthening potency of Mg alloys: A first-principles calculations

• The strengthening effect is larger for uniform dispersion than segregative case.
• The weaker Mg bonds near doping area lead to smaller strength for segregative case.
• The homogenization treatment is necessary in Mg–Al–Zn alloys.

Effects of distributions of Al, Zn and Al+Zn atoms on the strength property of Mg alloys are studied by simulating the tensile processes from first-principles calculations. The alloying elements dispersing uniformly result in larger ideal tensile strength than those distributing segregatively, and therefore correspond to a better strengthening effect in the former case. By analyzing the electronic structure, the inferior ideal strength for segregative distribution is attributed to the more seriously weakened Mg–Mg bonds around the doping region. This study demonstrates the necessary of homogenization treatment, and provides a guide for tailoring the mechanical properties of Mg alloys.

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