SUMMARY

Microstructure changes that occur during the deformation and heat treatments involved in wrought processing of metals are of central importance in achieving the desired properties or performance characteristics in the finished products. However, thorough understanding of the evolution of microstructure during thermo-mechanical processing of metallic materials is largely hampered by lack of methods for characterizing reliably their local (anisotropic) properties at the sub-micron length scales. Recently remarkable advances in nanoindentation data analysis techniques have been made which now make it possible to obtain quantitative information about the local mechanical properties of constituent individual grains in polycrystalline metallic samples. In this work, I propose the use a novel approach that combines mechanical property information obtained from spherical nanoindentation with the complementary structure information measured locally using Electron Backscatter Diffraction (EBSD) at the indentation site to systematically investigate the local structure-property relationships in fcc metals. The study will be focused on obtaining insights into the changes in local stored energies of polycrystalline metallic samples as a function of their crystal orientation at increasing deformation levels. Furthermore, using the same approach, I propose to investigate the evolution of microstructure and mechanical properties at or near grain boundaries in these samples, in order to better understand the role of such interfaces during deformation and recrystallization processes. The proposed work is expected to provide valuable insights into the processes of grain fragmentation and nucleation processes that occur during deformation and recrystallization respectively.