Crystal plasticity finite element simulation of lattice rotation and x-ray diffraction during laser shock-compression of Tantalum

P. Avraam; D. McGonegle; P. G. Heighway; C. E. Wehrenberg; E. Floyd; A. Comley; J. M. Foster; J. Turner; S. Case; J. S. Wark

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arXiv · 2108.05166

Crystal plasticity finite element simulation of lattice rotation and x-ray diffraction during laser shock-compression of Tantalum

P. Avraam·D. McGonegle·P. G. Heighway·C. E. Wehrenberg·E. Floyd·A. Comley·J. M. Foster·J. Turner·S. Case·J. S. Wark

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Abstract

Wehrenberg et. al. [Nature 550 496 (2017)] used ultrafast in situ x-ray diffraction at the LCLS x-ray free-electron laser facility to measure large lattice rotations resulting from slip and deformation twinning in shock-compressed laser-driven [110] fibre textured tantalum polycrystal. We employ a crystal plasticity finite element method model, with slip kinetics based closely on the isotropic dislocation-based Livermore Multiscale Model [Barton et. al., J. Appl. Phys. 109 (2011)], to analyse this experiment. We elucidate the link between the degree of lattice rotation and the kinetics of plasticity, demonstrating that a transition occurs at shock pressures of $\sim$27 GPa, between a regime of relatively slow kinetics, resulting in a balanced pattern of slip system activation and therefore relatively small net lattice rotation, and a regime of fast kinetics, due to the onset of nucleation, resulting in a lop-sided pattern of deformation-system activation and therefore large net lattice rotations. We demonstrate a good fit between this model and experimental x-ray diffraction data of lattice rotation, and show that this data is constraining of deformation kinetics.

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P. Avraam, D. McGonegle, P. G. Heighway, C. E. Wehrenberg, E. Floyd, A. Comley, J. M. Foster, J. Turner, S. Case, J. S. Wark. 2021-08-11. Crystal plasticity finite element simulation of lattice rotation and x-ray diffraction during laser shock-compression of Tantalum. https://arxiv.org/abs/2108.05166

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