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Micro-scale characterization of deformation and distortion in ductile (poly)crystals by synchrotron X-ray beams

  • Alexander M. Korsunsky (a1), Brian Abbey (a1), Felix Hofmann (a1), Igor Dolbnya (a2), Steve P. Collins (a2), Mengyin Xie (a1) and Xu Song (a1)...

Abstract

Most engineering structural metallic alloys are used in polycrystalline form. The nature of the mechanical response of these systems is complex and hierarchical, spanning a range of scales. Lattice strains, distortions and defects (notably, dislocations) nucleate, interact, pile up at grain boundaries and self-organize at the (sub)micrometre scale. Individual grains experience strong interactions with their neighbours and geometric features (cracks, notches). Groups of grains sharing common orientation find themselves embedded within large ensembles possessing certain statistical properties (size distributions, preferred orientation, etc.). Ultimately, the macroscopic properties of grain aggregates are determined by this hierarchy of interactions. Notably, while collective properties such as stiffness are relatively well represented by averages, strength properties associated with fracture, fatigue crack propagation, creep and damage show a strong dependence on the local microscopic conditions of the ‘weakest link’. Ongoing improvements in the spatial resolution of X-ray imaging and tomography and the availability of micro-focused X-ray beams open up a number of opportunities for the study of the structure and deformation at (sub)micrometre scales. Fundamental questions concerning the scale dependence and strain gradient effects in solids can now be tackled by the combination of synchrotron X-ray methods and suitably refined deformation modelling. In this study, a range of methodologies and experimental configurations are presented that have allowed us to develop improved insight into the physical mechanisms of plastic deformation in ductile metallic alloys. Examples include white-beam energy-dispersive diffraction, micro-beam Laue diffraction, scanning micro-beam diffraction topography, high-resolution reciprocal space mapping and imaging. Connections are established with advanced numerical models of polycrystal deformation using strain gradient plasticity and discrete dislocation dynamics modelling.

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Corresponding author

Email address for correspondence: alexander.korsunsky@eng.ox.ac.uk

References

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Daymond, M. R., Bourke, M. A. M., VonDreele, R. B., Clausen, B. & Lorentzen, T. 1997 Use of Rietveld refinement for elastic macrostrain determination and for evaluation of plastic strain history from diffraction spectra. J. Appl. Phys. 82, 15541562.
Gaucherin, G., Hofmann, F., Belnoue, J. P. & Korsunsky, A. M. 2009 Crystal plasticity and hardening: a dislocation dynamics study. Procedia Eng. 1, 241244.
Hofmann, F., Abbey, B., Song, X., Dolbnya, I. & Korsunsky, A. M. 2010 Intragranular lattice misorientation mapping by synchrotron x-ray micro-beams: Laue vs energy-resolved Laue vs monochromatic reciprocal space analysis. Int. J. Mod. Phys. B 24, 279287.
Hofmann, F., Song, X., Eve, S., Collins, S. R. & Korsunsky, A. M. 2009 Synchrotron based reciprocal space mapping and dislocation substructure analysis. Mater. Lett. 63, 10771081.
Korsunsky, A. M., Jarnes, K. E. & Daymond, M. R. 2004 Intergranular stresses in polycrystalline fatigue: Diffraction measurement and self-consistent modelling. Eng. Fract. Mech. 71, 805812.
Song, X., Zhang, S. Y. & Korsunsky, A. M. 2010 Strain gradient polycrystal plasticity analysis: FE modeling and synchrotron X-ray diffraction. Int. J. Mod. Phys. B 24, 1017.

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