A Method to Study the Effect of Electromigration on the Evolution of Microstructure in Tungsten

Abstract

In this work, a molecular dynamics–based framework is developed to investigate the influence of electromigration on the microstructural evolution of tungsten. Based on the electron wind force model, defect-associated atoms are identified using common neighbor analysis (CNA), enabling selective application of the driving force while maintaining mechanical equilibrium and periodic boundary conditions. Simulations of current-assisted annealing in a semi-2D polycrystalline tungsten model demonstrate that electron wind force accelerates grain boundary migration and lowers the temperature required to achieve comparable grain boundary densities, with the effect intensifying at higher force magnitudes. Furthermore, Arrhenius analysis indicates that electromigration primarily reduces the activation energy for grain boundary migration, exerting only a modest effect on the pre-exponential factor. In contrast, experimental recrystallization kinetics exhibit substantially stronger reductions in both parameters, thereby highlighting the critical role of nucleation processes. Overall, the methodology provides a validated framework for studying current-assisted microstructural evolution in tungsten.