Experimental and numerical investigations of anisotropic plasticity response in polycrystalline copper by nanoindentation

Abstract

The deformation behavior of crystalline materials is influenced by microstructural characteristics such as crystallographic orientation and grain boundary. In this study, nanoindentation experiments and crystal plasticity finite element simulations are used to investigate the effects of these microstructural features on the mechanical properties of polycrystalline copper. A crystal plasticity constitutive model embedded with geometrically necessary dislocations is developed to simulate the indentation mechanical response of grains with different orientations. The results show that the indentation behavior of polycrystalline copper exhibits significant anisotropy due to variations in the distributions of statistically stored dislocations and geometrically necessary dislocations. Moreover, grain boundary plays a crucial role in determining the anisotropy and indentation size effect. These findings provide insights into the design of materials for plasticity applications.