Size effects in miniaturized polycrystalline FCC samples: Strengthening versus weakening

This paper focuses on a computational-experimental analysis of sample geometry dominated and grain dominated size effects in miniaturized polycrystalline FCC components, where the grain size, orientation and grain boundaries play an important role. Experimental and numerical findings elucidate the joint contribution of first-order and second-order size effects for this type of components. The intrinsic competition between the weakening and strengthening contributions resulting from these effects is commented and further analysed. It is shown that a second-order crystal plasticity model is needed to account for the simultaneous contributions of both size effects.