Dislocation nucleation mechanisms from fcc/bcc incoherent interfaces

Using atomistic simulations, we study the nucleation and emission of dislocations from face-centered cubic/body-centered cubic (fcc/bcc) incoherent interfaces in which interface dislocations only have in-plane Burgers vectors. We show that nucleation sites and preferred slip systems are associated with interface regions with intense localized shear and are not solely determined by Schmid factors. Activation barriers for nucleation from the interface are lower than those for homogeneous nucleation, indicating that flat fcc/bcc incoherent interfaces can act as viable sources of lattice dislocations. Published by Elsevier Ltd. on behalf of Acta Materialia Inc.