An assessment of the lattice strain in the CrMnFeCoNi high-entropy alloy
Publication Date
2016-09-28Journal Title
Acta Materialia
ISSN
1359-6454
Publisher
Elsevier
Volume
122
Pages
11-18
Language
English
Type
Article
This Version
VoR
Metadata
Show full item recordCitation
Owen, L., Pickering, E., Playford, H., Stone, H., Tucker, M., & Jones, N. (2016). An assessment of the lattice strain in the CrMnFeCoNi high-entropy alloy. Acta Materialia, 122 11-18. https://doi.org/10.1016/j.actamat.2016.09.032
Abstract
The formation of single phase solid solutions from combinations of multiple principal elements, with differing atomic radii, has led to the suggestion that the lattices of high-entropy alloys (HEAs) must be severely distorted. To assess this hypothesis, total scattering measurements using neutron radiation have been performed on the CrMnFeCoNi alloy and compared with similar data from five compositionally simpler materials within the same system. The Bragg diffraction patterns from all of the studied materials were similar, consistent with a face-centered cubic structure, and none showed the pronounced dampening that would be expected from a highly distorted lattice. A more detailed evaluation of the local lattice strain was made by considering the first six coordination shells in the pair distribution functions (PDF), obtained from the total scattering data. Across this range, the HEA exhibited the broadest PDF peaks but these widths were not disproportionately larger than those of the simpler alloys. In addition, of all the materials considered, the HEA was at the highest homologous temperature, and hence the thermal vibrations of the atoms would be greatest. Consequently, the level of local lattice strain required to rationalise a given PDF peak width would be reduced. As a result, the data presented in this study do not indicate that the local lattice strain in the equiatomic CrMnFeCoNi HEA is anomalously large.
Keywords
high-entropy alloys, neutron diffraction, lattice strains, pair correlation function
Relationships
Is supplemented by: https://doi.org/10.17863/CAM.4890
Sponsorship
The authors would like to thank the EPSRC/Rolls-Royce Strategic Partnership for funding (EP/M005607/1 and EP/H022309).
Funder references
EPSRC (EP/H500375/1)
UNIVERSITY OF BIRMINGHAM (FB EPSRC) (EP/H022309/1)
EPSRC (EP/M005607/1)
Embargo Lift Date
2100-01-01
Identifiers
External DOI: https://doi.org/10.1016/j.actamat.2016.09.032
This record's URL: https://www.repository.cam.ac.uk/handle/1810/261123
Rights
Attribution 4.0 International, Attribution 4.0 International, Attribution 4.0 International
Recommended or similar items
The following licence files are associated with this item: