First-Principles Simulation of the High-Pressure Melting Points of Dilute Solid-Solution Mg-Al and Al-Mg Alloys

Author of the article:LI Liting 1,2 , GAO Xingyu 1 , YANG Zhen 2 , XIAN Jiawei 1 , SONG Haifeng 1

Author's Workplace：1. Laboratory of Computational Physics, Institute of Applied Physics and Computational Mathematics, Beijing 100088, China; 2. Institute for Applied Physics, University of Science and Technology Beijing, Beijing 100083, China

Key Words：dilute solid-solution alloys; high-pressure melting point; first-principles molecular dynamics; Mg-Al alloys; Al-Mg alloys; similar atomic environment method; solid-liquid coexistence method

Abstract：Despite extensive investigations on the high-pressure melting curves of magnesium (Mg) and aluminum (Al),
there have been very few reports on those of Mg-Al and Al-Mg alloys. In this work, first-principles molecular dynamics
simulation of the high-pressure melting points of dilute solid-solution alloys was carried out by combining structural
modelling of disordered solid-solution alloys using the similar atomic environment (SAE) method and melting point
simulation using the solid-liquid coexistence method. Based on this, the high-pressure melting points of two dilute
solid-solution alloys, a Mg-Al alloy AZ31B, and an Al-Mg alloy LF6Al, were then calculated. Our preliminary calculations
show that at high pressures, the melting temperature of LF6Al is slightly lower than that of Al, and the melting temperature
of AZ31B is very close to that of Mg. This work paves the way for further investigation of the effects of alloy composition
on the high-pressure melting of Mg-Al and Al-Mg alloys.