Densities and character of dislocations and size-distribution of subgrains in deformed metals by X-ray diffraction profile analysis

The density and the character of dislocations and the size-distribution of grains or subgrains were determined by a new procedure of X-ray diffraction (XRD) profile analysis in copper specimens deformed by equal channel angular pressing (ECA) or cold rolling. The anisotropic strain broadening of diffraction profiles was accounted for by dislocation contrast factors. The screw or edge character of dislocations was determined by analyzing the dislocation contrast factors. Three size parameters and the dislocation density were obtained by the modified Williamson-Hall and Warren-Averbach procedures. Assuming that the grain-size distribution is log-normal, the median, in, and the variance, sigma, of the size distribution of grains or subgrains were obtained from these three size parameters. (C) 2001 Elsevier Science B.V. All rights reserved.