Advances in understanding deformation structures from high resolution reciprocal space mapping: Workshop to promote the use of high-energy x-ray diffraction experiments and detailed computational analyses for understanding multiscale phenomena in crystalline materials
Activity: Lecture and oral contribution
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Advances in understanding deformation structures from high resolution reciprocal space mapping W. Pantleon, Risø DTU, email@example.com (Co-authors: C. Wejdemann, B. Jakobsen, U. Lienert, and H.F. Poulsen) With high angular resolution high energy three-dimensional X-ray diffraction established at APS beamline 1-ID quantitative information is gained about dislocation structures in individual grains in the bulk of a macroscopic specimen by acquiring reciprocal space maps. In high resolution three-dimensional reciprocal space maps of tensile deformed copper, individual, almost dislocation-free subgrains are identified from high-intensity peaks and distinguished by their unique combination of orientation and elastic strain; dislocation walls manifest themselves as a smooth cloud of lower intensity. The elastic strain varies only slightly within each subgrain, but significantly between different subgrains. In average, subgrains experience backward strains, whereas dislocations walls are strained in forward direction. Based on these observations a revision of the classical composite model for explaining asymmetric peak profiles is formulated in full accordance with the experimental findings. When pre-deformed specimens are pulled along a perpendicular direction, a reversal of the radial profile asymmetry is observed. The structural evolution during such a strain path change is rationalized in the above mentioned model.
Place: Argonne, USA
Place: Argonne, USA