ROLE OF MAGNESIUM IN DYNAMIC STRAIN AGING OF ALUMINIUM MAGNESIUM ALLOY USING ATOMISTIC MODELLING

Abstract

Al-Mg alloys can be utilised in a broad variety of applications, many of which are in harsh environments or at high temperatures due to their wide range of favourable properties. The 5xxx series of alloys, which exhibit strong corrosion resistance together with very good mechanical qualities to deal under the hardest situations, such as maritime settings, are a notable example of such materials. Computational modelling can be a powerful tool to study behaviour of materials at the molecular level. In this work the atomistic modelling technique is adopted to simulate Al-Mg and structure optimization is obtained when the most accurate force field is applied on the structure. Dynamic strain ageing within the material is studied. Multi-objective genetic algorithm is used to substitute magnesium in aluminium near the dislocation core. Binding energy and segregation energy of magnesium near the dislocation core is calculated and a pattern of substitution is observed. The activation barrier is calculated for the migration of magnesium across the dislocation glide plane using Nudge elastic band (NEB) approach. All simulations have been performed on Large-scale Atomic/Molecular Massively Parallel Simulator (LAMMPS) and visualised on OVITO whereas the results obtained are matched with the already existing literature wherever necessary.