In situ Laue diffraction of metallic micropillars

Laue micro-diffraction performed on metallic micropillars prior to deformation revealed the presence of strain gradients and planar defects in samples made by focused ion beam (FIB) milling. In situ Laue micro-diffraction shows that such pre-existing gradients can play a role in the determination of the first activated slip system, and thus leading to un-expected geometrical strengthening. Lattice rotations resulting in the formation of substructures are observed at stresses well below the strength of the pillars usually defined as the stress at 5% strain.