Lattice rotations of individual bulk grains. Part 1: 3D X-ray characterization

Three-dimensional X-ray diffraction has been applied to characterise the plastic deformation of individualgrains deeply embedded in a 99.6% pure aluminium specimen. The specimen is 4 mm thick with an average grain size of 75 μm. The average latticerotation for each grain as well as the degree of internal orientation spread within the grain is measured in-situ during 6% elongation. The rotation paths for 95 grains with nearly random initial orientations are reported. The quality of this data set is sufficient to make distinctions between plasticity models. The rotation paths exhibit a clear dependence on the initial orientation, while the influence of grain interaction is relatively small. All grains deform plastically. Averaged over grains and reflections the rotation of the tensile axis and the FWHM of the internal spread is 2.0 and 0.8°, respectively, at 6% strain.