Journal of Nondestructive Evaluation

, Volume 33, Issue 4, pp 504–514 | Cite as

Non-destructive Testing of Paint Coatings on Steel Plates by Ultrasonic Reflectometry

  • X. Zhang
  • F. AugereauEmail author
  • D. Laux
  • E. Le Clezio
  • N. A. Ismaili
  • M. Kuntz
  • G. Despaux


An ultrasonic reflectometry method has been used successfully to detect elasticity changes following the curing of 100 \(\upmu \)m thick epoxy films (DGEBA-PAA) coated onto 1.5 mm thick steel plates. The method employs a goniometric apparatus to measure the reflection coefficient amplitude around 5 MHz followed by a standard FFT analysis of the reflected signal. A specific ultrasonic wave mode was identified which was dependent on, and correlated with, the presence of the coating layer. The goniometer angle associated with this mode was different from that associated with Lamb modes of the plate, enabling the new mode to be detected reliably. The sensitivity of the new mode to variations in the paint mass density, longitudinal and transverse velocities and thickness has been quantified numerically by using Brekhovskikh’s model with due account taken of the finite width of the ultrasonic fields of the transducers. The method was tested for the detection of the evolution of the coating elasticity during curing at 80 \(^{\circ }\)C for 400 h. Compensation was applied to correct for the effect of the natural swelling of the paint layer on the angular position of the tracked mode, and this was validated experimentally. The evolution of the angular position was found to offer a reliable means to detect elasticity changes during the cure of the coating. The mass density variation in the coating during cure only weakly affected the angular position. This method will provide a promising tool for the non destructive evaluation of paint coatings, particularly in service for the detection of ageing effects in the longer term.


Epoxy paint coatings Characterization of cure state Thermal ageing detection Angular reflectometry Ultrasonic spectroscopy Wave propagation in coated plates 


  1. 1.
    Lindrose, A.M.: Ultrasonic wave and moduli changes in a curing epoxy resin. Exp. Mech. 18, 227–232 (1978)CrossRefGoogle Scholar
  2. 2.
    White, S.R., Mather, P.T., Smith, M.J.: Characterisation of the cure-state od DGEBA-DDS epoxy using ultrasonic, dynamic mechanical, and thermal probes. Polym. Eng. Sci. 42(1), 51–67 (2002)CrossRefGoogle Scholar
  3. 3.
    Sugasawa, S.: Measurements of elastic properties of plasma-sprayed coatings using bulk ultrasonic pulses. Jpn. J. Appl. Phys. 43(5B), 3109–3114 (2004)CrossRefGoogle Scholar
  4. 4.
    Sugasawa, S., Shibata, T.: Evaluation of elastic constants of antifouling paint film using group delay spectrum method. Jpn. J. Appl. Phys. 46(7B), 4583–4588 (2007)CrossRefGoogle Scholar
  5. 5.
    Alig, I., et al.: Monitoring of film formation, curing and ageing of coatings by an ultrasonic reflection method. Prog. Org. Coat. Coat. Sci. Internat. 58, 200–208 (2007)CrossRefGoogle Scholar
  6. 6.
    Alig, I., et al.: Polymerization and network formation of UV-curable materials monitored by hyphenated real-time ultrasound reflectometry and near-infrared spectroscopy (RT-US/NIRS). Prog. Org. Coat. 55(2), 88–96 (2006)CrossRefGoogle Scholar
  7. 7.
    Challis, R.E., Wilkinson, G.P., Freemantle, R.J.: Errors and uncertainties in the ultrasonic reflectometry method for measuring acoustic impedance. Meas. Sci. Technol. 9, 692–700 (1998)CrossRefGoogle Scholar
  8. 8.
    Kinra, V.K., Zhu, C.: Ultrasonic nondestructive evaluation of thin (sub-wavelength) coatings. J. Acoust. Soc. Am. 93(5), 2454–2467 (1993)CrossRefGoogle Scholar
  9. 9.
    Bridge, B., Ramli, A.: Non-destructive evaluation of the quality (cure) of polymeric coatings on steel foods cans by means of high frequency Lamb wave propagation : a preliminary study. J. Mater. Sci. 25, 1794–1802 (1990)CrossRefGoogle Scholar
  10. 10.
    Lavrentyev, A.I., Rokhlin, S.I.: Determination of elastic moduli, density, attenuation and thickness of a layer using ultrasonic spectroscopy at two angles. J. Acoust. Soc. Am. 102(6), 3467–3477 (1997)CrossRefGoogle Scholar
  11. 11.
    Viktorov, I.A.: Rayleigh and Lamb Waves : Physical Theory and Applications. Plenum press, New York (1967)CrossRefGoogle Scholar
  12. 12.
    Brekhovskikh, L.M.: Waves in Layered Media. Academic press, New York (1960)Google Scholar
  13. 13.
    Folds, D.L., Loggins, C.D.: Transmission and reflection of ultrasonic waves in layered media. J. Acous. Soc. Am. 62, 1102–1109 (1977) Google Scholar
  14. 14.
    Goodman, J.W.: The angular spectrum of plane waves. Introduction to Fourier Optics, pp. 55–61. McGraw-Hill, New York (1996)Google Scholar
  15. 15.
    Chen, W., Wu, J.: Reflectometry using longitudinal, shear and Rayleigh waves. Ultrasonics 38, 909–913 (2000)CrossRefGoogle Scholar
  16. 16.
    Kino, G.S.: Acoustic Waves: Devices, Imaging and Analog Signal Processing. Prentice-Hall, Englewood Cliffs, New Jersey (1987)Google Scholar
  17. 17.
    Lavrentyev, A.I., Rokhlin, S.I.: An ultrasonic method for determination of elastic moduli, density, attenuation and thickness of a polymer coating on a stiff plate. Ultrasonics 39, 211–221 (2000)CrossRefGoogle Scholar
  18. 18.
    Abdelkader, A.F., White, J.R.: Curing characteristics and internal stresses in epoxy coatings: effect of crosslinking agent. J. Mater. Sci. 40, 1843–1854 (2005)CrossRefGoogle Scholar
  19. 19.
    Galant, C., et al.: Thermal and radio-oxidation of epoxy coatings. Prog. Org. Coat. 69, 322–329 (2010)CrossRefGoogle Scholar

Copyright information

© Springer Science+Business Media New York 2014

Authors and Affiliations

  • X. Zhang
    • 1
  • F. Augereau
    • 1
    Email author
  • D. Laux
    • 1
  • E. Le Clezio
    • 1
  • N. A. Ismaili
    • 1
  • M. Kuntz
    • 2
  • G. Despaux
    • 1
  1. 1.Univ. MontpellierIESMontpellierFrance
  2. 2.EDF R&DMoret-sur-loing CedexFrance

Personalised recommendations