Simple method of measuring thicknesses of surface-hardened layers by laser ultrasonic technique

Lee, Yong; Kitazawa, So; Patel, Rikesh

Abstract

We proposed a simple non-contact inspection method using a laser ultrasonic technique to measure the thickness of a surface-hardened layer. This measurement is based on the dependence of a surface-wave velocity on the thickness of the hardened layers. In this case, it is essential to measure the surface-wave velocity with a wavelength comparable to the thickness of a hardened layer. However, it is not easy to selectively generate the surface waves with a desired wavelength. Thus we proposed the method where the surface waves with a desired wavelength are extracted using bandpass electrical filters. This method is simpler than the conventional one based on dispersion because the surface-wave velocity is directly obtained from measured temporal waveforms. We applied the method to measure the thickness of hardened layers and showed that the results were in good agreement with that obtained by the conventional method and numerical results.

Citation

Lee, Y., Kitazawa, S., & Patel, R. (2021). Simple method of measuring thicknesses of surface-hardened layers by laser ultrasonic technique. Japanese Journal of Applied Physics, 60(7), Article 072002. https://doi.org/10.35848/1347-4065/ac030f

• Journal Article Type: Article
• Acceptance Date: May 18, 2021
• Online Publication Date: Jun 9, 2021
• Publication Date: 2021-07
• Deposit Date: Jun 23, 2021
• Publicly Available Date: Jun 10, 2022
• Journal: Japanese Journal of Applied Physics
• Print ISSN: 0021-4922
• Electronic ISSN: 1347-4065
• Publisher: IOP Publishing
• Peer Reviewed: Peer Reviewed
• Volume: 60
• Issue: 7
• Article Number: 072002
• DOI: https://doi.org/10.35848/1347-4065/ac030f
• Keywords: General Engineering; General Physics and Astronomy
• Public URL: https://nottingham-repository.worktribe.com/output/5564993
• Publisher URL: https://iopscience.iop.org/article/10.35848/1347-4065/ac030f