Skip to Main content Skip to Navigation
Journal articles

Relative relevance of mobility and driving force on edge dislocation climb by the vacancy mechanism

Abstract : In this work we examine the driving force for edge dislocations to climb in α-Fe from atomistic and mesoscale viewpoints. We study the bias for the climb process depending on the dislocation orientation and the applied stress due to both the gradient of the chemical potential and the transport coefficients. Both terms are modified by the applied stress and therefore contribute to climb. Surprisingly, even though the vacancy migration barrier distribution is modified by the external stress as obtained by nudged-elastic band calculations, the mobilities resulting from a kinetic Monte Carlo model applied on the obtained energy landscape are indistinguishable, independently of the stress. Moreover, an object kinetic Monte Carlo (OKMC) model including the effect of the dislocation strain field to first order shows indeed a slight anisotropic component in the diffusion in more complex dislocation configurations. However, the OKMC results highlight the fact that the thermodynamic component is the dominant driving force. We conclude that in α-Fe under thermal conditions, the main source of bias is given by the difference in vacancy chemical potentials, which is small enough to hinder the process for dynamic atomistic simulations.
Complete list of metadata

https://hal-cea.archives-ouvertes.fr/cea-03223086
Contributor : Contributeur Map Cea Connect in order to contact the contributor
Submitted on : Monday, May 10, 2021 - 4:11:42 PM
Last modification on : Sunday, May 23, 2021 - 3:27:37 AM
Long-term archiving on: : Wednesday, August 11, 2021 - 7:58:19 PM

File

 Restricted access
To satisfy the distribution rights of the publisher, the document is embargoed until : 2021-10-01

Please log in to resquest access to the document

Licence


Distributed under a Creative Commons Attribution - NonCommercial - NoDerivatives 4.0 International License

Identifiers

Collections

Citation

Enrique Martinez, Alankar Alankar, Alfredo Caro, Thomas Jourdan. Relative relevance of mobility and driving force on edge dislocation climb by the vacancy mechanism. Computational Materials Science, Elsevier, 2021, 193, pp.110378. ⟨10.1016/j.commatsci.2021.110378⟩. ⟨cea-03223086⟩

Share

Metrics

Record views

14