Surface and Interfacial Energies of Mg17Al12–Mg System

Abstract

For upscale simulation and modeling of magnesium alloys, data of surface and interfacial energies are critical. In this work, we calculated the surface energies of Mg17Al12 β-phase with different surface configurations by using molecular dynamic simulations. Surface terminations were carefully selected to calculate the energy of β-phase. The lowest energy surface for each crystallographic plane was determined by varying the surface termination. The results show that surfaces occupied by higher fraction of magnesium atoms generate lower surface energies. The interfacial energy for Mg17Al12 β-phase and Mg matrix was calculated as well based on the Burger’s orientation relationship. We found that the lowest energy surface of Mg17Al12 does not generate the lowest interfacial energy. The interfacial energy for Mg17Al12 β-phase and a \( \left\{ {10\bar{1}2} \right\} \) twin was also calculated. The interfacial energy increases by ~250 mJ/m2 due to the change in orientation relationship between Mg17Al12 and the matrix after twinning.