Dresden 2014 – scientific programme

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MM: Fachverband Metall- und Materialphysik

MM 62: Topical session: X-ray and neutron scattering in materials science IV - High Energy Single Grain Diffraction

MM 62.1: Topical Talk

Thursday, April 3, 2014, 17:30–18:00, BAR 205

High Energy Single Grain Diffraction — •Ulrich Lienert — Deutsches Elektronen-Synchrotron, Hamburg, Germany

Over the last decade methodologies have been developed that enable the assignment of diffraction spots from multigrain diffraction patterns to individual grains. High energy synchrotron radiation has been employed for the investigation of polycrystalline bulk materials during thermo-mechanical processing. From an experimental point of view, the techniques can be classified according to the sample-to-detector distance which governs the real and reciprocal space coverage and resolutions. The grain boundary topology and orientation gradients have been evaluated from diffraction patterns observed in close proximity to the sample. Large area detectors positioned further away from the sample can still capture several complete diffraction rings and complete lattice strain tensors, center-of-mass grain positions, and volumes have been evaluated. Finally, area detectors have been placed very far behind the sample increasing reciprocal space resolution on cost of coverage. The formation and evolution of subgrain structure has been observed and radial peak profiles have been analyzed in terms of inter- and intra-subgrain strains. The basic principles will be reviewed and selected case studies will be presented.