Atomistic simulations of plasticity in heterogeneous nanocrystalline Ni lamella

Atomistic simulations were performed on heterogeneous nanocrystalline (NC) Ni lamella made up of alternating NC and single crystalline (SC) layers to explore the effect of the heterogeneous microstructure on their mechanical response. It was found that the heterogeneous NC Ni lamella exhibit higher strength and better crack resistance than the pure NC Ni. After quantitatively analyzing the distribution of Von Mises shear strain in each sample, we found that the SC layer in heterogeneous NC Ni lamella can not only strengthen the whole sample following the conventional composite strengthening mechanism, but also homogenize the plastic strains in the NC layer and suppress the crack nucleation and propagation. The findings from this study can provide valuable insight into improving nanomaterial processing techniques, and have implications for the design of gradient or heterogeneous structures with superior properties.