期刊
ACTA MATERIALIA
卷 200, 期 -, 页码 570-580出版社
PERGAMON-ELSEVIER SCIENCE LTD
DOI: 10.1016/j.actamat.2020.09.041
关键词
Dislocations; Plasticity; Chromium; Magnetism
资金
- TGCC [2019-096847]
- French Tripartite Institute (CEA-EDF-Framatome) through the ICOMB project
The influence of magnetism on the properties of screw dislocations in body-centered cubic chromium is investigated by means of ab initio calculations. Screw dislocations having Burgers vectors 1/2 < 111 > and < 100 > are considered, following experimental observations showing activity for both slip systems. At low temperature, chromium has a magnetic order close to antiferromagnetism along < 100 > directions, for which 1/2 < 111 > is not a periodicity vector. Hence, dislocations with Burgers vectors 1/2 < 111 > generate magnetic faults when shearing the crystal, which constrain them to coexist and move pairwise, leading to dissociated < 111 > super-dislocations. On the other side, < 100 > is a periodicity vector of the magnetic order of chromium, and no such magnetic fault are generated when < 100 > dislocations glide. Dislocation properties are computed in the magnetically ordered and non magnetic phases of chromium for comparison purposes. We report a marginal impact of magnetism on the structural properties and energies of dislocations for both slip systems. The Peierls energy barrier opposing dislocation glide in {110} planes is comparable for both 1/2 (111) {110} and (100) {110} slip systems, with lower Peierls stresses in the magnetically ordered phase of chromium. (C) 2020 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据