Oxygen-dislocation interaction in titanium from first principles

SCRIPTA MATERIALIA

卷:162

Article

Chaari, Nermine^1,3  Rodney, David²  Clouet, Emmanuel¹ 

[1] Univ Paris Saclay, DEN Serv Rech Met Phys, CEA, F-91191 Gif Sur Yvette, France

[2] Univ Claude Bernard Lyon 1, Inst Lumiere Matiere, CNRS, F-69622 Villeurbanne, France

[3] 10 Rue Juliette Recamier, F-69006 Lyon, France

关键词: Dislocation;    Plasticity;    Titanium;    Oxygen;    Hardening;   

DOI  :  10.1016/j.scriptamat.2018.11.025

来源: Elsevier

【 摘 要 】

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. (C) 2018 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

【 授权许可】

Free