By studying the X-ray line broadening in several reflections, the fractions of certain dislocation types could be determined experimentally. The contribution of strain to the

line broadening was generally anisotropic. On the basis of the dislocation model, modified Williamson-Hall and Warren-Averbach procedures were suggested in which g and g2 were replaced by g√C and g2C, where C was the average dislocation contrast factor. Here, C could be evaluated theoretically for various crystal systems and dislocation types (edge, screw) by using numerical methods. On the other hand, by analyzing the strain anisotropy, C could be determined by experiment. By comparing experimental and theoretical C-values, the specific fractions of dislocation types could be determined. This procedure was carried out for fine-grained 3N-purity Cu after deformation well into stage III. The ratio began with a high fraction (90%) of screw dislocations but, during deformation up to 0.3, this shifted in favour of edge dislocations (75%).

Measurement of Screw and Edge Dislocation Density by Means of X-Ray Bragg Profile Analysis. E.Schafler, M.Zehetbauer, T.Ungàr: Materials Science and Engineering A, 2001, 319-321, 220-3