Experimental characterisation of laser surface remelting via acoustic emission wavelet decomposition

Mojškerc, Bor (author), Ravnikar, Dunja (author), Šturm, Roman (author)

This paper presents a novel technique of monitoring laser surface remelting (LSR) via measurements of process generated acoustic emission (AE). The LSR conditions include a variable laser power level and an ambient air or argon 5.0 inert gas atmosphere. The microstructure and microhardness of the remelted surface layer are evaluated. The recorded AE signal datasets are analysed via the wavelet decomposition technique. The resulting energy and energy proportions of approximation and detail coefficients are calculated. The decomposed AE signal features are evaluated in correlation with the LSR process conditions. A supervised machine learning cubic support vector machine classifier type is used for the classification of laser pulses. The experimental results show an overall 98% classification accuracy into the corresponding LSR laser power level and atmosphere conditions, confirming the utility of monitoring the LSR process and the resulting material surface layer characteristics via the AE wavelet decomposition technique.

• Language: English
• Keywords: lasers, surface remelting, acoustic emission, signal processing, wavelet
• Work type: Article
• Typology: 1.01 - Original Scientific Article
• Organization: FS - Faculty of Mechanical Engineering
• Publication status: Published
• Publication version: Version of Record
• Year: 2021
• Number of pages: Str. 3365-3374
• Numbering: Vol. 15
• PID: 20.500.12556/RUL-132158
• UDC: 621.7+621.9:535(045)
• ISSN on article: 2238-7854
• DOI: 10.1016/j.jmrt.2021.10.010
• COBISS.SI-ID: 80445699
• Publication date in RUL: 14.10.2021

Record is a part of a journal

• Title: Journal of materials research and technology
• Shortened title: J. mater. res. technol.
• Publisher: Elsevier
• ISSN: 2238-7854
• COBISS.SI-ID: 519699737

Licences

• License: CC BY 4.0, Creative Commons Attribution 4.0 International
• Link: http://creativecommons.org/licenses/by/4.0/
• Description: This is the standard Creative Commons license that gives others maximum freedom to do what they want with the work as long as they credit the author.

Secondary language

• Language: Slovenian
• Keywords: laserji, površinsko pretaljevanje, akustična emisija, procesiranje signalov, valčna dekompozicija

Projects

• Funder: ARRS - Slovenian Research Agency
• Project number: P2-0270
• Name: Proizvodni sistemi, laserske tehnologije in spajanje materialov