Atomistic simulation of kink structure on edge dislocation in bcc iron

Abstract

Based on the general theory of dislocation and kink, we have constructed the three kink models corresponding to the 1/2 〈111〉{011} and 1/2 〈111〉{112} edge dislocations (EDs) in bcc Fe using the molecular dynamics method. We found that the geometric structure of a kink depends on the type of ED and the structural energies of the atom sites in the dislocation core region, as well as the geometric symmetry of the dislocation core and the characteristic of the stacking sequence of atomic plane along the dislocation line. The formation energies and widths of the kinks on the 1/2 〈111〉{011} and 1/2 〈111〉{112} EDs are calculated, the formation energies are 0.05eV and 0.04eV, and widths are 6.02b and 6.51b, respectively (b is the magnitude of the Burgers vector). The small formation energies indicate that the formation of kink in the edge dislocation is very easy in bcc Fe.