Distribution of c- and a-dislocations in tubes of Zr alloys

A new X-ray method of generalized pole figures (GPFs) was developed to determine distributions of c- and a-dislocations in alpha-Zr crystallites of Zr-based alloy tubes for the needs of the nuclear industry. The method uses the Warren approach by the treatment of X-ray line profiles, acquired separately for all grain orientations by successive positions of the sample in the course of texture measurements. For the first time, obtained values of the dislocation densities p, and A, were presented as distributions depending on grain orientations in the stereographic projection of studied tube samples, as well as distributions of grain volume fractions v(rho(c)) and v(rho(a)). The main advantage of the used method as compared with the standard one consists in the systematic description of the orientation inhomogeneity of dislocation distributions. This inhomogeneity proves to be very significant both in as-rolled and annealed tubes. Features of the dislocation distribution in tubes are closely related to their crystallographic texture.