低固溶镁-铝和铝-镁合金高压熔点的第一性原理模拟

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

以往虽然针对镁(Mg)、铝(Al)单质的高压熔化曲线开展了较多研究,但是对于Mg-Al和Al-Mg合金的高压熔化却鲜有报道。本工作结合固溶无序结构建模的相似原子环境(SAE)方法,以及熔点模拟的固液共存法,实现了低固溶合金高压熔点的第一性原理分子动力学模拟。在此基础上初步研究了2种低固溶Mg-Al和Al-Mg合金的高压熔点,这2种合金分别是AZ31B和LF6Al。计算发现,高压下LF6Al的熔化温度略低于Al的熔化温度,而AZ31B的熔化温度非常接近Mg的熔化温度。为后续深入研究组分变化对Mg-Al和Al-Mg合金高压熔点的影响规律奠定了基础。

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.