PNNL

Abstract

Nanocrystalline Cu/Ni composites subjected to continuous shear deformation and subsequent thermal annealing is investigated by molecular dynamics (MD) simulations to reveal the mechanisms of defect substructure evolution and atomic mixing under rotational diamond anvil cells (RDAC) process. The continuous shear deformation is achieved by on-the-fly periodic boundary adjustment. The results indicate that partial dislocation (nano-deformation twin) assisted subgrain boundary formation is the dominant mechanism of defect substructure evolution, while triple junction sliding induced atomic mixing is the key mechanism of atomic mixing in nanocrystalline Cu/Ni composite under severe shear.