Grain boundary-induced stress localization during compression deformation of polycrystalline 316L stainless steel

Understanding the mechanisms governing stress localization in polycrystalline materials is paramount for optimizing their mechanical properties and performance. Here, we investigate the grain boundary-induced stress localization phenomenon during compression deformation of polycrystalline 316L stainless steel through a combination of experimental and computational approaches. Utilizing a custom-built indentation setup and crystal plasticity finite element (CPFE) simulations, we elucidate the intricate interplay between microstructural features, dislocation mechanisms, and stress distribution. Experimental results reveal significant stress concentrations at grain boundaries, while CPFE simulations demonstrate the influence of grain size on stress response, with finer grains exhibiting higher stresses due to increased accumulation of geometrically necessary dislocations (GNDs). Our findings underscore the critical role of microstructural features, particularly grain boundaries and grain size, in governing the mechanical behavior of polycrystalline materials under compression loading conditions. This study provides valuable insights for designing and optimizing materials for various engineering applications.