Determining the crystallographic orientation of hexagonal crystal structure materials with surface acoustic wave velocity measurements

Lain'e, Steven J.; Dryburgh, Paul; Smith, Richard J.; Marrow, Paul; Lain�, Steven J.; Sharples, Steve D.; Clark, Matt; Li, Wenqi

Abstract

© 2020 Throughout our engineered environment, many materials exhibit a crystalline lattice structure. The orientation of such lattices is crucial in determining functional properties of these structures, including elasticity and magnetism. Hence, tools for determining orientation are highly sought after. Surface acoustic wave velocities in multiple directions can not only highlight the microstructure contrast, but also determine the crystallographic orientation by comparison to a pre-calculated velocity model. This approach has been widely used for the recovery of orientation in cubic materials, with accurate results. However, there is a demand to probe the microstructure in anisotropic crystals - such as hexagonal close packed titanium. Uniquely, hexagonal structure materials exhibit transverse isotropic linear elasticity. In this work, both experimental and simulation results are used to study the discrete effects of both experimental parameters and varying lattice anisotropy across the orientation space, on orientation determination accuracy. Results summarise the theoretical and practical limits of hexagonal orientation determination by linear SAW measurements. Experimental results from a polycrystalline titanium specimen, obtained by electron back scatter diffraction and spatially resolved acoustic spectroscopy show good agreement (errors of ϕ1=5.14° and Φ=6.99°). Experimental errors are in accordance with those suggested by simulation, according to the experimental parameters. Further experimental results demonstrate dramatically improved orientation results (Φ error

Citation

Lain'e, S. J., Dryburgh, P., Smith, R. J., Marrow, P., Lainé, S. J., Sharples, S. D., Clark, M., & Li, W. (2020). Determining the crystallographic orientation of hexagonal crystal structure materials with surface acoustic wave velocity measurements. Ultrasonics, 108, Article 106171. https://doi.org/10.1016/j.ultras.2020.106171

• Journal Article Type: Article
• Acceptance Date: May 5, 2020
• Online Publication Date: May 29, 2020
• Publication Date: Dec 1, 2020
• Deposit Date: Jun 2, 2020
• Publicly Available Date: Jun 2, 2020
• Journal: Ultrasonics
• Print ISSN: 0041-624X
• Electronic ISSN: 1874-9968
• Publisher: Elsevier
• Peer Reviewed: Peer Reviewed
• Volume: 108
• Article Number: 106171
• DOI: https://doi.org/10.1016/j.ultras.2020.106171
• Keywords: Orientation determination; Crystallographic characterisation; Surface acoustic waves; Hexagonal crystal; Grain structure
• Public URL: https://nottingham-repository.worktribe.com/output/4519123
• Publisher URL: https://www.sciencedirect.com/science/article/pii/S0041624X20301104
• Additional Information: This article is maintained by: Elsevier; Article Title: Determining the crystallographic orientation of hexagonal crystal structure materials with surface acoustic wave velocity measurements; Journal Title: Ultrasonics; CrossRef DOI link to publisher maintained version: https://doi.org/10.1016/j.ultras.2020.106171; Content Type: article; Copyright: Crown Copyright © 2020 Published by Elsevier B.V.