Local mechanical behavior and slip band formation within grains of thin sheets

In this work, thin sheet metal specimens with large grains are subjected to tensile tests. Deformation, slip band formation and orientation changes are measured locally after applying strain increments. Orientation gradient mapping (OGM) is introduced to visualize the distribution of hardening zones. It is found that hardening zones originate not from the grain boundary regions but rather concentrate at grain boundary triple junctions. Simulations of slip band formation are performed to investigate the role of anisotropic elasticity and possible slip system classes at the beginning of plastic deformation. Comparisons with experiments show that slip nucleation is strongly affected by elastic anisotropy. Consequently, elastic anisotropy cannot be neglected.