Molecular dynamics analysis of the interaction between screw dislocation and prismatic dislocation loop in BCC iron

Abstract

This paper presents the molecular dynamics analysis of the interaction between a screw dislocation and a prismatic dislocation loop in BCC iron. The diameter of the prismatic dislocation loop, the combination of the Burgers vectors of the prismatic dislocation loop and the screw dislocation, and the temperature of the system were varied and analyzed in terms of two aspects: the mechanism of the dislocations reaction and the Critical Resolved Shear Stress (CRSS). As a result, when the Burgers vectors of the screw dislocation and the dislocation loop coincided, a helical dislocation was generated by pair annihilation of the dislocations, and when the Burgers vectors did not coincide, the helical dislocation was generated by sliding of a〈100〉 dislocations generated by the addition of the Burgers vectors. It was also found that the CRSS was significantly increased by the generation of helical dislocations.