Atomic-scale simulations of the interaction between a moving dislocation and a bcc/fcc phase boundary

In the past, molecular dynamics (MD) simulations have shown that grain boundaries are very strong obstacles to dislocation motion. Whereas such studies typically have been performed for boundaries between grains with the same crystal structure, in the present study the interaction of a moving edge dislocation and a boundary between a bcc (Fe) and an fcc (Cu) phase with almost identical lattice distances in the glide planes has been studied using MD. It is found that an edge dislocation can be transmitted from the bcc- into the fcc-regime, but not vice versa. This may be due to the splitting of the edge dislocation into Shockley partials inside the fcc region.