Crystal subgrain misorientations observed by X-ray topography in reflection

Based on the principles of conservation of momentum and energy for X-ray diffraction, a vector description is obtained for the displacement of adjacent subgrain images in reflection topographs. The analysis includes, in addition to those crystal parameters defining the misorientation at a subgrain boundary, the combined effects of (horizontal and vertical) divergence in the incident X-ray beam and of the position where the X-ray images are recorded. The vector description is matched with a stereographic projection method of analysis for describing the subgrain misorientations. These total considerations are applied to the characterization of subgrain boundaries grown into a nickel single-crystal solidified along [010], including specification of the dislocation structure within the boundaries.