Molecular Dynamics Simulation of Temperature Effects on the Hot Deformation and Microstructural Evolution of Al-Mg-Si Aluminum Alloy

Abstract

In this work, molecular dynamics simulations are applied to systematically examine the influence of varying temperatures (300 K, 500 K, and 700 K) on the Elevated-temperature compression behavior and micromechanical characteristics of polycrystalline Al-Mg-Si aluminum alloy. A nanopolycrystalline model was established to analyze the stress–strain response, dislocation evolution, and crystal structure changes occurring during the deformation process. The simulation results show that the yield strength and elastic modulus both decline as temperature increases, indicating a pronounced thermal softening effect. During the early stage of plastic deformation, dislocations mainly have their nucleation sites at grain boundaries and then propagate into the grain interiors, where they form interconnected networks along with stacking faults and twin structures. This work reveals the thermal deformation mechanisms of Al-Mg-Si aluminum alloy at the atomic scale and provides theoretical guidance for the optimization of its hot-working processes.