X-ray diffraction analysis of substructures in plastically deformed BCC materials

A procedure for line-shape analysis of broadened X-ray (or neutron) diffraction peaks is presented and specified for b.c.c. materials, which takes into account the effect of interfaces, internal stress of the 2nd kind and a dislocation distribution with weak defect correlation. Application of the technique is demonstrated by the estimation of dislocation densities in plastically deformed a-iron and steel. The results confirm that X-ray line-broadening analysis is suitable for integrated substructure characterization, but it becomes also evident that local structural inhomogeneity and the texture of the sample material must carefully included into the interpretation of experimental data.