The Library
Calculation of dislocation binding to helium-vacancy defects in tungsten using hybrid ab initio-machine learning methods
Tools
Grigorev, Petr, Goryaeva, Alexandra M., Marinica, Mihai-Cosmin, Kermode, James R. and Swinburne, Thomas D. (2023) Calculation of dislocation binding to helium-vacancy defects in tungsten using hybrid ab initio-machine learning methods. Acta Materialia, 247 . 118734. doi:10.1016/j.actamat.2023.118734 ISSN 1359-6454.
|
PDF
WRAP-calculation-dislocation-binding-helium-vacancy-defects-tungsten-using-hybrid-ab-initio-machine-learning-methods-Kermode-2023.pdf - Accepted Version - Requires a PDF viewer. Available under License Creative Commons Attribution Non-commercial No Derivatives 4.0. Download (4Mb) | Preview |
Official URL: http://dx.doi.org/10.1016/j.actamat.2023.118734
Abstract
Calculations of dislocation-defect interactions are essential to model metallic strength, but the required system sizes are at or beyond ab initio limits. Current estimates thus have extrapolation or finite size errors that are very challenging to quantify. Hybrid methods offer a solution, embedding small ab initio simulations in an empirical medium. However, current implementations can only match mild elastic deformations at the ab initio boundary. We describe a robust method to employ linear-in-descriptor machine learning potentials as a highly flexible embedding medium, precisely matching dislocation migration pathways whilst keeping at least the elastic properties constant. This advanced coupling allows dislocations to cross the ab initio boundary in fully three dimensional defect geometries. Investigating helium and vacancy segregation to edge and screw dislocations in tungsten, we find long-range relaxations qualitatively change impurity-induced core reconstructions compared to those in short periodic supercells, even when multiple helium atoms are present. We also show that helium-vacancy complexes, considered to be the dominant configuration at low temperatures, have only a very weak binding to screw dislocations. These results are discussed in the context of recent experimental and theoretical studies. More generally, our approach opens a vast range of mechanisms to ab initio investigation and provides new reference data to both validate and improve interatomic potentials.
Item Type: | Journal Article | |||||||||||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Subjects: | Q Science > QC Physics Q Science > QD Chemistry |
|||||||||||||||||||||
Divisions: | Faculty of Science, Engineering and Medicine > Engineering > Engineering | |||||||||||||||||||||
Library of Congress Subject Headings (LCSH): | Plasticity, Dislocations in crystals, Tungsten , Density functionals, Mathematical physics, Quantum chemistry -- Research, Machine learning | |||||||||||||||||||||
Journal or Publication Title: | Acta Materialia | |||||||||||||||||||||
Publisher: | Pergamon-Elsevier Science Ltd | |||||||||||||||||||||
ISSN: | 1359-6454 | |||||||||||||||||||||
Official Date: | 1 April 2023 | |||||||||||||||||||||
Dates: |
|
|||||||||||||||||||||
Volume: | 247 | |||||||||||||||||||||
Article Number: | 118734 | |||||||||||||||||||||
DOI: | 10.1016/j.actamat.2023.118734 | |||||||||||||||||||||
Status: | Peer Reviewed | |||||||||||||||||||||
Publication Status: | Published | |||||||||||||||||||||
Access rights to Published version: | Restricted or Subscription Access | |||||||||||||||||||||
Date of first compliant deposit: | 13 February 2023 | |||||||||||||||||||||
Date of first compliant Open Access: | 3 February 2024 | |||||||||||||||||||||
RIOXX Funder/Project Grant: |
|
Request changes or add full text files to a record
Repository staff actions (login required)
View Item |
Downloads
Downloads per month over past year