In Situ EBSD Observations of the Evolution in Crystallographic Orientation with Deformation

Abstract

Automated electron backscatter diffraction (EBSD) analysis is frequently used to investigate the change in crystallographic orientation that occurs when polycrystalline materials deform. Through crystallographic slip, the crystal lattice within a grain rotates. However, the crystal lattice rotation in each grain is constrained by the lattices of the neighboring grains while rotating. These competing factors lead to the development of orientation gradients and substructure in deformed polycrystals. In situ uniaxial tensile deformation was carried out in the scanning electron microscope while employing simultaneous automated EBSD analysis to characterize grain rotation, both in terms of the overall rotation of the lattice and the development of orientation gradients within the grain. The impact of these factors can be seen at the grain boundaries in the deformed structure where the local orientations diverge from the orientation at the grain interior. Automated in situ EBSD analysis allows the quantitative nature of specific metrics based on local variations in orientation to illuminate the physical mechanisms underlying the stress strain response during a mechanical test.