Orientation gradients in grain boundary proximity studied by EBSD

The microstructure is characterized at sub-grain level spatial resolution using Electron Backscatter Diffraction (EBSD) in samples submitted to interrupted uniaxial tension in a notched sample and to typical solicitations in forming process through Nakajima tests with different sample geometries.

The use of a notched sample allows performing a local study of the microstructural evolution in a set of identifiable grains as the material deforms, while the samples corresponding to Nakajima tests are used to study the behavior of the orientation gradient with the distance to the grain boundary under a statistical approach. From the latter analysis, two new EBSD-based parameters are introduced, named Gradient Average Severity (GAS) and Boundary Effective Thickness (BET).