Measurement of X-ray diffraction-line broadening induced by elastic mechanical grain interaction

• Published in: Journal of applied crystallography 2014-02, Vol.47 (1), p.391-401
• Main Authors: Koker, M. K. A., Welzel, U., Mittemeijer, E. J.
• Format: Article
• Language: English
• Subjects: Crystallites; Crystallography; Diffraction; grain interaction; Grains; Mathematical analysis; Mathematical models; Position measurement; strain; Synchrotrons; X-ray diffraction-line broadening; X-rays
• ISSN: 1600-5767; 0021-8898; 1600-5767
• DOI: 10.1107/S1600576713032202

Various grain‐interaction models have been proposed in the literature to describe the stress and strain behavior of individual grains within a massive aggregate. Diffraction lines exhibit a response to the occurrence of a strain distribution in the diffracting crystallites, selected by the direction of the diffraction vector with respect to the specimen frame of reference, by correspondingly induced diffraction‐line broadening. This work provides a report of synchrotron diffraction investigations dedicated to the measurement of the experimentally observable diffraction‐line broadening induced by external elastic loading of various polycrystalline specimens. The experimentally obtained broadening data have been compared with those calculated adopting various grain‐interaction models. Although such grain‐interaction models have been proven to accurately predict the average (X‐ray) diffraction measured lattice strain, as derived from the diffraction‐peak position, the present results have demonstrated that the extent of the diffraction‐line broadening due to grain interactions, as calculated by employing these grain‐interaction models, is much smaller than the experimentally determined broadening. The obtained results have vast implications for diffraction‐line broadening analysis and the understanding of the elastic behavior of massive polycrystals.