Understanding structural evolution of nanostructures during deformation from 2D (3D) experiments

Understanding how microstructures evolve during deformation and/or annealing treatments is of fundamental interest, as the underlying structure dictates the resulting property spectrum. This issue is even more important for nanomaterials, where interfaces and defect populations have a stronger effect on mechanical properties. In addition, for nanometals the grain architecture can also be an important parameter for improvement of mechanical properties. However, synthesis of bulk high strength materials by severe deformation with tailored and desired properties requires a thorough understanding about the processes governing their microstructural evolution at large and severe strains. Here, we summarize findings from 2D (3D) experiments uncovering these restoration processes. Interestingly, the main mechanisms seem to change with deformation temperature, causing formation of extremely elongated grain structures at intermediate deformation temperature regimes. Apart from discussing the reasons for this finding, we also present recent results focusing on the mechanisms triggering these restoration processes at low temperatures, highlighting the crucial role of plastic strain to facilitate these processes.