Threshold displacement in the tungsten-carbon system
File(s)
Published version
Author(s)
Jackson, Matthew
Fossati, Paul CM
Than, Yan Ren
Grimes, Robin W
Type
Journal Article
Abstract
Threshold displacement energies (Ed) of carbon and tungsten in tungsten carbide (WC), W2C, tungsten and diamond are predicted using molecular dynamics. The spatial dependence of Ed is probed by considering a geodesic projection of a symmetrically distinct arc of crystallographic directions for each lattice site. Further, the definition of threshold displacement is explored by making the distinction between atomic displacement (E¯dispd
) and defect formation (E¯defd
). Predicted values of E¯defd
compare favourably to experimental observations for tungsten and tungsten carbide. Results confirm that E¯defd
and E¯dispd
are strongly structure dependent. Differences between E¯dispd
and E¯defd
are commensurate with rapid defect recombination within the timeframe of the simulations for some species and structures but not universally. The probability of displacement and defect formation as a function of primary knock-on energy is also reported. Previously developed models for the average displacement of the primary knock-on atom based on kinetic energy and momentum-dependent drag terms are generally found to provide a useful level of approximation. Anisotropy is investigated and results highlight differences due to structures.
) and defect formation (E¯defd
). Predicted values of E¯defd
compare favourably to experimental observations for tungsten and tungsten carbide. Results confirm that E¯defd
and E¯dispd
are strongly structure dependent. Differences between E¯dispd
and E¯defd
are commensurate with rapid defect recombination within the timeframe of the simulations for some species and structures but not universally. The probability of displacement and defect formation as a function of primary knock-on energy is also reported. Previously developed models for the average displacement of the primary knock-on atom based on kinetic energy and momentum-dependent drag terms are generally found to provide a useful level of approximation. Anisotropy is investigated and results highlight differences due to structures.
Date Issued
2024-11
Date Acceptance
2024-06-21
Citation
Philosophical Magazine, 2024, 104 (21), pp.959-976
ISSN
1478-6435
Publisher
Taylor and Francis Group
Start Page
959
End Page
976
Journal / Book Title
Philosophical Magazine
Volume
104
Issue
21
Copyright Statement
© 2024 The Author(s). Published by Informa UK Limited, trading as Taylor & Francis Group. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. The terms on which this article has been published allow the posting of the Accepted Manuscript in a repository by the author(s) or with their consent.
License URL
Identifier
http://dx.doi.org/10.1080/14786435.2024.2372826
Publication Status
Published
Date Publish Online
2024-07-16