Interaction of edge dislocations with voids in tungsten

Tungsten is widely used as a material capable of withstanding extreme operating conditions and is one of the candidates for use in fusion and Generation IV fission reactors. Atomistic modelling implemented to solve various material science problems is an indispensable approach for improving material properties. This work analyzes the interaction of an edge dislocation with a void in single-crystal tungsten with the help of molecular dynamics simulation. Two different approaches for studying the dynamics of dislocations in tungsten that differ in boundary conditions are compared. Multiple interactions of the dislocation and void at different temperatures are investigated, and based on the obtained stress–strain curves, the dislocation obstacle strength for voids having various diameters is defined. It is shown that when applied to a crystal with small voids, the model with the fixed boundary conditions returns incorrect results. Moreover, the influence of the cell size for the model with periodic boundary conditions is analyzed, and the case of a non-central interaction of a dislocation with a void is considered. The obtained results improve our understanding of the mechanical response of irradiated materials.