In-situ observation of small-angle X-ray scattering by dislocations

Ultra-small-angle X-ray scattering by dislocations in single-crystal aluminum has been observed in situ as a function of plastic deformation. The scattering is strongly dependent upon sample orientation, with single dislocations, dislocation dipoles, and the dislocation distribution within walls each exhibiting distinct scattering profiles. Among the microstructural features that have been observed are: the correlations between the ordered fraction of dislocations, the presence of dislocation dipoles, the increasing dislocation content with increasing strain, and the decreasing width of the interface between dislocation walls and the surrounding nearly-dislocation-free material with increasing deformation.