Molecular dynamics simulation of alloying characteristics of Al–Mg nanoparticles under different process heating conditions

Abstract

The effect of thermal process parameters on the alloying of Al–10Mg (wt%) system has been studied in molecular dynamics approach. Five distinct values of heating rate have been considered for Al and Mg nanoparticles (NPs) to melt, coalesce followed by identical cooling. Detailed investigation of Al-Mg NPs alloying has been done in terms of alloying temperature, atomic migration, coalescence kinetics and mechanical characteristics for various heating rates were carried out. Prior to the alloying simulation, component melting simulations of Al and Mg single particles (SPs) were conducted to determine the melting temperature of NPs and to inspect their individual thermo-stability. From the change in potential energy, its evident that the melting temperature of the component NPs significantly depends on heating rates. Following the component melting, alloying simulations were conducted in three distinct phases: (i) heating, (ii) relaxation, and (iii) cooling and solidification. Following the solidification, uniaxial tensile test simulation was done on a block cut to characterise the mechanical behaviour in context to dislocation analysis, HCP evolution, stacking fault analysis and corresponding stress–strain relationship. Obtained results showed a substantial affiliation of heating rates and coalescence kinetics but showed minimal effect on mechanical properties.