The interaction between screw dislocations and oxygen interstitial atoms is studied with ab initio calculations in hexagonal close-packed titanium. Our calculations evidence a strong repulsion when the solute atoms are located in the dislocation glide plane, leading to spontaneous cross-slip, which allows the dislocation to bypass the atomic obstacle. This avoidance process explains several experimental observations in titanium in presence of oxygen: (1) a larger lattice friction against screw dislocation motion, (2) a reduction of the dislocation glide distance in prismatic planes and (3) an enhancement of cross-slip in pyramidal planes.
@article{arxiv.1811.10250,
title = {Oxygen-dislocation interaction in titanium from first principles},
author = {Nermine Chaari and David Rodney and Emmanuel Clouet},
journal= {arXiv preprint arXiv:1811.10250},
year = {2018}
}