Analyses of X-ray diffraction line-broadening were carried out on highly textured Zr-2.5Nb specimens which had been deformed in tension to produce well-controlled dislocation structures. An iterative deconvolution method was used to extract the broadening function for the material; using a Zr single crystal and a 0%-deformed specimen as standards. In both cases, for specific tensile tests, a significant contribution to basal line broadening was observed which was clearly not directly related to the dislocation structure generated by the deformation. That is, so-called c-component dislocations with a component of their Burgers vectors perpendicular to the basal plane. Calculations showed that the extent of basal line broadening could not be attributed to the secondary effect of strain from a-type dislocations (that is, dislocations with Burgers vectors parallel to the basal plane). It was concluded that most of the line broadening was the result of intergranular strain distributions. The latter were most prominent for grains that were oriented with their c-axes perpendicular to the tensile-deformation axis, and resulted in basal-plane line broadening even when there were few, if any, c-component dislocations present.

Determination of Dislocation Densities in HCP Metals from X-Ray Diffraction Line-Broadening Analysis. M.Griffiths, D.Sage, R.A.Holt, C.N.Tome: Metallurgical and Materials Transactions A, 2002, 32[3A], 859-65