Hostname: page-component-cd9895bd7-mkpzs Total loading time: 0 Render date: 2024-12-26T18:31:24.742Z Has data issue: false hasContentIssue false

Ultrasonic assessment of coatings dispersion curvesby microdefocusing

Published online by Cambridge University Press:  15 September 2005

D. Laux*
Affiliation:
LAIN, University Montpellier 2, Place Eugène Bataillon, CC082, 34095 Montpellier Cedex 05, France
F. Augereau
Affiliation:
LAIN, University Montpellier 2, Place Eugène Bataillon, CC082, 34095 Montpellier Cedex 05, France
G. Despaux
Affiliation:
LAIN, University Montpellier 2, Place Eugène Bataillon, CC082, 34095 Montpellier Cedex 05, France
Get access

Abstract

In 2001 we have published a paper [1] in which an ultrasonic method using a large bandwidth transducer with a spherical lens and based on acoustic waves separation near the focal region was presented. We have shown that compared to traditional acoustic microscopy (acoustic signature) the size of the zone analysed on bulk samples was highly reduced. This method is now extended to thin films on bulk substrates. Experimental dispersion curves for thin DLC (Diamond Like Carbon) films on steel are presented. The ultrasonic velocity of leaky Sezawa mode is assessed on a large bandwidth even in zones where the transducer is not very efficient. We show that the signal processing used enlarges the frequency domain explored. Such an element is essential for inverse problem treatment and coating elastic modulus calculation. Once again we show that the length of defocusing can by highly reduced. Hence, the zone analysed on the sample is smaller.

Keywords

Type
Research Article
Copyright
© EDP Sciences, 2005

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Laux, D., Despaux, G., Augereau, F., Eur. Phys. J. Appl. Phys. 17, 163 (2002) CrossRef
D. Royer, E. Dieulesaint, Ondes élastiques dans les solides. Tome 1. Propagation libre et guidée, Enseignement de la Physique (Masson, 1996)
J. Sirven, Les ondes : du linéaire au non linéaire, Masson Sciences (Dunod, 2000)
R. Truell, C. Elbaum, B.B. Chick, Ultrasonic Methods in Solid State Physics (Academic Press, New York and London, 1969)
I.A. Viktorov, Rayleigh and Lamb waves (Plenum, New York, 1967)
K. Sezawa, Dispersion of elastic waves propagated on the surface of stratified bodies and on curved surfaces, Bulletin of the Earthquake Research Institute, Tokyo Imperial University, February (1927)
Brunet, N., Cros, B., Despaux, G., Saurel, J.M., Eur. Phys. J. Appl. Phys. 2, 209 (1998) CrossRef
A. Briggs, Acoustic microscopy (Clarendon Press, Oxford, 1992)
Somekh, M.G. et al., Philos. Mag. A 49, 179 (1984) CrossRef
Leonhardt, M. et al., Surf. Coat. Tech. 185, 292 (2004) CrossRef
Schneider, D., Witke, Th., Schwarz, Th., Schöneich, B., Schultrich, B., Surf. Coat. Tech. 126, 136 (2000) CrossRef
W. Chen, J. Wu, Ultrasonics 909 (2000)
Yung Chun Lee, Shin Pin Ko, NDT&E Int. 34, 191 (2001) CrossRef
Lematre, M. et al., NDT&E Int. 35, 493 (2002) CrossRef
F. Glangeaud, J.L. Mari, Wave separation, Institut Français du Pétrole (Éditions Technip, 1994)
J.L. Mari, F. Glangeaud, F. Coppens, Traitement du signal pour Géologues et Géophysiciens, Publications de l'Institut Français du Pétrole (Éditions Technip, 1997)
Jin, S. Seo et al., Signal Process.-Image 19, 325 (2004)
Matlab 5.3 User's guide