Role of stacking fault energy in confined layer slip in nanolaminated Cu

Metallic nanolaminates exhibit superior strength compared to their coarsely laminated counterparts. For layer thicknesses in the range of a few to tens of nanometers, the strength of these materials is related to the stress required for individual dislocations to thread through the nanometer-thick layers, a motion called confined layer slip (CLS). Here, using atomistic simulations, we model the CLS in nanolaminated Cu with incoherent interfaces, with a focus on the role of stacking fault energies (SFEs), which are varied by up to one order of magnitude while other material parameters are largely kept the same. Our simulations found that (i) the intrinsic SFE affects the structures of both the dislocation core and the interfaces and (ii) the critical stress for CLS scales positively with the energy of the incoherent interface, but negatively with the ratio between the intrinsic SFE and the unstable SFE.