Inspection of Ceramic Coatings Using Nanoindentation and Frequency Domain Photoacoustic Microscopy

  • Steen, T.L. (Department of Aerospace and Mechanical Engineering) ;
  • Basu, S.N. (Department of Manufacturing Engineering 110 Cummington Street, Boston University) ;
  • Sarin, V.K. (Department of Manufacturing Engineering 110 Cummington Street, Boston University) ;
  • Murray, T.W. (Department of Aerospace and Mechanical Engineering)
  • Published : 2006.12.30

Abstract

The elastic properties and thickness of mullite environmental barrier coatings grown through chemical vapor deposition (CVD) on silicon carbide substrates were measured using frequency domain photoacoustic microscopy. In this technique, extremely narrow bandwidth surface acoustic waves are generated with an amplitude modulated laser source. A photorefractive crystal based interferometer is used to detect the resulting surface displacement. The complex displacement field is mapped as a function of source-to-receiver distance in order to extract the wavelength of the surface acoustic wave at a given excitation frequency, and the phase velocity is determined. The coatings tested exhibited spatial variations in thickness and mechanical properties. The measured surface wave dispersion curves were used to extract an effective value for the elastic modulus and the coating thickness. Nanoindentation was used to validate the measurements of the effective elastic modulus. The average elastic modulus measured through the coating thickness using nanoindentation is compared to the effective modulus found using the photoacoustic system. Optical microscopy is used to validate the thickness measurements. The results indicate that the photoacoustic microscopy technique can be used to estimate the effective elastic properties in coatings exhibiting spatial inhomogeneities, potentially providing valuable feedback for the optimization of the CVD growth process.

Keywords

References

  1. Alleyne, D., and Cawley, P. (1991) Two Dimensional Fourier Transform Method for the Measurement of Propagation Multi-Mode Signals, J. Acoust. Soc. Am., 89, pp. 1159-1168 https://doi.org/10.1121/1.400530
  2. Balogun, O., and Murray, T.W., (2006) A Frequency Domain Laser Based Ultrasonic System for Time Resolved Measurement of Broadband Acoustic Transients, J. Appl. Phys., 100, 034902 https://doi.org/10.1063/1.2218467
  3. Bellan, C, and Dhers J. (2004) Evaluation of Young Modulus of CVD Coatings by Different Techniques, Thin Solid Films, 469-470, pp. 214-220 https://doi.org/10.1016/j.tsf.2004.08.182
  4. Berezina, S., Zinn, P., Schneider, D., Fei, D., and Rebinsky, D. (2004) Combining Brillion Spectroscopy and Laser-SAW Technique for Elastic Pproperty Characterization of Thick DLC Films, Ultrasonics, 43, pp. 87-93 https://doi.org/10.1016/j.ultras.2004.03.006
  5. Blouin, A., and Monchalin, J.-P. (1994) Detection of Ultrasonic Motion of a Scattering Surface by Two-Wave Mixing in a Photorefractive GaAs Crystal, Appl. Phys. Lett., 65, pp. 932-934 https://doi.org/10.1063/1.112153
  6. Briggs, A.D. (1992) Acoustic Microscopy, Clarendon Press, Oxford, pp. 15-294
  7. Briggs, G.A.D. (1995) Advances in Acoustic Microscopy, Vol 1, Plenum Press, New York, pp. 153-217
  8. Cheng, A., Murray, T.W., and Achenbach, J.D., (2001) Simulation of Laser-Generated Ultrasonic Waves in Layered Plates, J. Acoust. Soc. Am., 110, pp. 848-855 https://doi.org/10.1121/1.1381536
  9. Delaye, P., Blouin, A., Drolet, D., Montmorillon, L.-A., Roosen, G., and Monchalin, J.-P. (1997) Detection of Ultrasonic Motion of a Scattering Surface by Photorefractive InP:Fe under an Applied dc Field, J. Opt. Soc. Am. B., 14, pp. 1723-1734 https://doi.org/10.1364/JOSAB.14.001723
  10. Doerner, M. F., and Nix, W. D. (1986) A Method for Interpreting the Data from Depth-Sensing Indentation Instruments, J. Mater. Res., 1, pp. 601-616 https://doi.org/10.1557/JMR.1986.0601
  11. Duggal, A.R., Rogers, J.A., and Nelson, K.A. (1992) Real-Time Optical Characterization of Surface Acoustic Modes of Polyamide Thin-Film Coatings, J. Appl. Phys., 72, pp. 2823-2839 https://doi.org/10.1063/1.351535
  12. Farnell, G.W., and Adler, E.L. (1972) Elastic Wave Propagation in Thin Layers, Edited by W. P. Mason and R. N. Thurston, Academic, New York, Phys. Acoust., Vol. IX, pp. 35-127
  13. Flannery, B.P., Press, W.H., Teukolsky, S.A., and Vettering, W. (1989) Numerical Recipes in C, Cambridge University Press, pp. 305-309
  14. Guo Z. and Achenbach, J.D. (2000) Integration of Modelling and Acoustic Microscopy Measurements for Thin Films, J. Acoust. Soc. Am., 107(5), pp. 2462-2471 https://doi.org/10.1121/1.428633
  15. Hou, P., Basu, S.N., and Sarin, V.K. (2001) Structure and High-Temperature Stability of Compositionally Graded CVD Mullite Coatings, Int. J. Refract. Met. Hard. Mater., 19, pp. 467-477 https://doi.org/10.1016/S0263-4368(01)00048-8
  16. Hurley, D.C., Tewary, V..K., and Richards, A.J. (2001) Surface Acoustic Wave Methods to Determine the Anisotropic Elastic Properties of Thin Films, Meas. Sci. Technol., 12, pp. 1486-1494 https://doi.org/10.1088/0957-0233/12/9/315
  17. lng, R. K., and Monchalin, J. -P. (1991) Broadband Optical Detection of Ultrasound by Two-Wave Mixing in a Photorefractive Crystal, Appl. Phys. Lett., 59, pp. 3233-3235 https://doi.org/10.1063/1.105742
  18. Ledbetter, H., Kim, S., Balzar, D., Crudele, S., and Kriven, W. (1998) Elastic Properties of Mullite, J. Am. Ceram. Soc., 81, pp. 1025-1028 https://doi.org/10.1111/j.1151-2916.1998.tb02441.x
  19. Maris, H.J. (1997) Picosecond Ultrasonics, Scientific American, 278, pp. 64-67
  20. Murray, T.W., and Balogun, O. (2004) High-Sensitivity Laser-Based Acoustic Microscopy Using a Modulated Excitation Source, Appl. Phys. Lett., 85(14), PP. 2974-2976 https://doi.org/10.1063/1.1802387
  21. Murray, T.W., Balogun, O., Steen, T.L., Basu, S.N., and Sarin, V-K. (2005) Inspection of Compositionally Gmullite Coatings Using Laser Based Ultrasonics, Int. J. Refract. Met. Hard. Mater., 23, pp. 322-329 https://doi.org/10.1016/j.ijrmhm.2005.05.021
  22. Neubrand, A., Hess, P. (1992) Laser Generation and Detection of Surface Acoustic Waves: Elastic Properties of Surface Layers, J. Appl. Phys., 71, pp. 227-238 https://doi.org/10.1063/1.350747
  23. Ohmura, T., and Matsuoka, S. (2003) Evaluation of Mechanical Properties of Ceramic Coatings on a Metal Substrate, Surf. Coat. Technol., 169-170, pp. 728-731 https://doi.org/10.1016/S0257-8972(03)00210-X
  24. Oliver, W.C. and Pharr, G.M. (1992) An Improved Technique for Determining Hardness and Elastic Modulus Using Load and Displacement Sensing Indentation Experiments, J. Mater. Res., 7, pp. 1564-1583 https://doi.org/10.1557/JMR.1992.1564
  25. Richardson, C.J.K., Ehrlich, M.J., and Wagner, J.W. (1999) Interferometric Detection of Ultrafast Thermoelastic Transients in Thin Films: Theory with Supporting Experiment, J. Opt. Soc. Am. B, 16(6), pp. 1007-1015 https://doi.org/10.1364/JOSAB.16.001007
  26. Rogers, J.A., Fuchs, M., Banet, M.J., Hanselman, J.B., Logan, R., and Nelson, K.A. (2000) Optical Generation and Characterization of Acoustic Waves in Thin Films, Annu. Rev. Mater. Sci., 30, pp. 117-157 https://doi.org/10.1146/annurev.matsci.30.1.117
  27. Vaz, F., Carvalho, S., Rebouta, L., Silva, M.Z., Paul, A. and Schneider, D. (2002) Young's Modulus of (Ti,Si)N Films by Surface Acoustic Waves and Indentation Techniques, Thin Solid Films, 408, pp. 160-168 https://doi.org/10.1016/S0040-6090(02)00132-3
  28. Zhang, F., Krishnaswamy, S., Fei, D., Rebinsky, D.A., and Feng, B. (2006) Ultrasonic Characterization of Mechanical Properties of Cr-and W-Doped Diamond-Like Carbon Hard Coatings, Thin Solid Films, 503, pp. 250-258 https://doi.org/10.1016/j.tsf.2005.11.057
  29. Ziebert, C., Ye, J.,Sell, K. and Ulrich, S. (2006) High-Resolution Depth Profiling of Mechanical Properties of Thick Cubic Boron Nitride Coatings, Surf. Coat. Technol., 200, pp. 6454-6458 https://doi.org/10.1016/j.surfcoat.2005.11.024