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arXiv · 2005.13336

Statistical mechanics of kinks on a gliding screw dislocation

M. Boleininger·M. Gallauer·S. L. Dudarev·T. D. Swinburne·D. R. Mason·D. Perez
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Abstract

The ability of a body-centered cubic metal to deform plastically is limited by the thermally activated glide motion of screw dislocations, which are line defects with a mobility exhibiting complex dependence on temperature, stress, and dislocation segment length. We derive an analytical expression for the velocity of dislocation glide, based on a statistical mechanics argument, and identify an apparent phase transition marked by a critical temperature above which the activation energy for glide effectively halves, changing from the formation energy of a double kink to that of a single kink. The analysis is in quantitative agreement with direct kinetic Monte Carlo simulations.

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M. Boleininger, M. Gallauer, S. L. Dudarev, T. D. Swinburne, D. R. Mason, D. Perez. 2020-05-27. Statistical mechanics of kinks on a gliding screw dislocation. https://doi.org/10.1103/physrevresearch.2.043254

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