Dislocation–interface interaction in nanoscale fcc metallic bilayers

Dislocation–interface interactions are investigated in a Ni–Cu bilayer using molecular mechanics simulations. Nanoindentation model is used to generate dislocations in the top Ni layer and study their propagation through coherent (1 1 1) fcc interface into Cu. Although dislocations do propagate through, the interface acts as a strong barrier to gliding dislocations and contributes considerably to the overall strain hardening of the nanolayered material. Mechanisms of dislocation–interface interactions are analyzed. In particular, spreading of a dissociated dislocation core at the interface and interfacial stacking fault formation are investigated along with their effect on the material strengthening.