Statistical mechanics of kinks on a gliding screw dislocation

Statistical mechanics of kinks on a gliding screw dislocation

Statistical mechanics of kinks on a gliding screw dislocation 150 150 UKAEA Opendata
UKAEA-CCFE-PR(21)01

Statistical mechanics of kinks on a gliding screw dislocation

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.

Collection:
Journals
Journal:
Physical Review Research
Publisher:
APS (American Physical Society)