Intrinsic structural transitions of the pyramidal I ⟨c plus a⟩ dislocation in magnesium

SCRIPTA MATERIALIA

卷:116

Article

Wu, Zhaoxuan^1,2  Curtin, W. A.¹ 

[1] Ecole Polytech Fed Lausanne, Inst Engn Mech, CH-1015 Lausanne, Switzerland

[2] Inst High Performance Comp, 1 Fusionopolis Way 16-16, Singapore 138632, Singapore

关键词: Magnesium;    Dislocations;    Plasticity;    Molecular dynamics simulations;   

DOI  :  10.1016/j.scriptamat.2016.01.041

来源: Elsevier

【 摘 要 】

The stability of a mixed < c + a > dislocation on the pyramidal I plane in magnesium is studied using molecular dynamics simulations. The dislocation is metastable and undergoes a thermally-activated transition to either a sessile, basal-dissociated < c + a > or a sessile basal-dissociated < c > dislocation plus an < a > dislocation. The transition is intrinsic to pure magnesium and occurs with an energy barrier of similar to 0.3 eV. The transformed structure is also consistent with experimental evidence in Ti and Zr, where pyramidal I slip is more prevalent. Enhancing the ductility of magnesium by stabilizing < c + a > slip on pyramidal I planes thus appears unlikely to be viable. (C) 2016 Elsevier Ltd. All rights reserved.

【 授权许可】

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