Finite element (FE) modeling is used to simulate the occurrence of plastic localization observed by transmission electron microscopy (nanoDIC) at the boundaries of aluminum nanocrystals inside an Al/Al2O3/Al three-layer laminate composite (with a total thickness of 300nm) that is subjected to in situ uniaxial tension. When loaded at low-strain rate (10-6 s-1), such composite exhibits huge strength (UTS>1.5 GPa) and significant ductility (in spite of the presence of a brittle metal oxide layer) [1].

The confrontation of model predictions to experimental observations indicates that both the composite tensile response and the heterogeneous strain field inside individual layers may be explained based on diffusion-controlled, rate-dependent deformation mechanisms operating in the vicinity of grain boundaries within the Al layers. The local diffusion fluxes and their contribution to the macroscopic strain are estimated as a function of the GB tilting relative to the tensile axis.