Next Article in Journal
Muscle Activity Detectors—Surface Electromyography in the Evaluation of Abductor Hallucis Muscle
Next Article in Special Issue
Free-Standing Complementary Asymmetric Metasurface for Terahertz Sensing Applications
Previous Article in Journal
Wideband Self-Calibration Method of Inductive CTs and Verification of Determined Values of Current and Phase Errors at Harmonics for Transformation of Distorted Current
Previous Article in Special Issue
Highly Sensitive Photoacoustic Microcavity Gas Sensor for Leak Detection
Open AccessArticle

Inspection of Trivalent Chromium Conversion Coatings Using Laser Light: The Unexpected Role of Interference on Cold-Rolled Aluminium

1
Department of Physics, Osnabrueck University, Barbarastrasse 7, 49076 Osnabrueck, Germany
2
Fraunhofer Institute for Manufacturing Technology and Advanced Materials IFAM, 28359 Bremen, Germany
*
Author to whom correspondence should be addressed.
Sensors 2020, 20(8), 2164; https://doi.org/10.3390/s20082164
Received: 1 March 2020 / Revised: 29 March 2020 / Accepted: 30 March 2020 / Published: 11 April 2020
(This article belongs to the Special Issue Optical Spectroscopy, Sensing, and Imaging from UV to THz Range)
Laser-based inspection of trivalent chromium conversion coatings on rough, cold-rolled aluminium substrates is studied from a basic physics perspective by means of angle and wavelength dependent measurements. As a result, we show that the correlation between the scattered laser light and the coating weight of the conversion layer is dominated by the phenomenon of interference. The combined experimental and numerical approach of our study is based on an appropriate layer model which was developed from a set of reference measurements of confocal microscopy, electron microscopy and X-ray photoelectron spectroscopy. The aluminium alloy AA3003 with a trivalent chromium conversion coating serves as an example. Our derived model is capable to reconstruct the reflectance of a laser beam at grazing incidence even for a pronounced surface roughness of R q 300   n m , for different coating thicknesses less than 70 n m corresponding to coating weights between zero and 0.5 g / m 2 and for laser wavelengths from 405 n m to 785 n m . In our discussion we outline the possibility to transfer the results to other aluminium alloys and/or other metallic substrates, as well as their potential for industrial applications such as 100% inline-capability, costs, velocity and ruggedness. View Full-Text
Keywords: laser-based inspection; interference; layer model; trivalent chromium conversion coating; cold-rolled aluminium; rough surface; AA3003 laser-based inspection; interference; layer model; trivalent chromium conversion coating; cold-rolled aluminium; rough surface; AA3003
Show Figures

Figure 1

MDPI and ACS Style

Rischmueller, J.; Toschke, Y.; Imlau, M.; Schlag, M.; Brüning, H.; Brune, K. Inspection of Trivalent Chromium Conversion Coatings Using Laser Light: The Unexpected Role of Interference on Cold-Rolled Aluminium. Sensors 2020, 20, 2164. https://doi.org/10.3390/s20082164

AMA Style

Rischmueller J, Toschke Y, Imlau M, Schlag M, Brüning H, Brune K. Inspection of Trivalent Chromium Conversion Coatings Using Laser Light: The Unexpected Role of Interference on Cold-Rolled Aluminium. Sensors. 2020; 20(8):2164. https://doi.org/10.3390/s20082164

Chicago/Turabian Style

Rischmueller, Joerg; Toschke, Yannic; Imlau, Mirco; Schlag, Mareike; Brüning, Hauke; Brune, Kai. 2020. "Inspection of Trivalent Chromium Conversion Coatings Using Laser Light: The Unexpected Role of Interference on Cold-Rolled Aluminium" Sensors 20, no. 8: 2164. https://doi.org/10.3390/s20082164

Find Other Styles
Note that from the first issue of 2016, MDPI journals use article numbers instead of page numbers. See further details here.

Article Access Map by Country/Region

1
Search more from Scilit
 
Search
Back to TopTop