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Effect of mechanical damage on thermal conduction of plasma-sprayed coatings

Published online by Cambridge University Press:  31 January 2011

Lanhua Wei
Affiliation:
Materials Science and Engineering Laboratory, National Institute of Standards and Technology, Gaithersburg, Maryland 20899
Antonia Pajares
Affiliation:
Materials Science and Engineering Laboratory, National Institute of Standards and Technology, Gaithersburg, Maryland 20899
Brian R. Lawn
Affiliation:
Materials Science and Engineering Laboratory, National Institute of Standards and Technology, Gaithersburg, Maryland 20899
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Abstract

A thermal wave methodology for monitoring the thermal conduction of ceramic coatings with accumulating mechanical damage is described. Tests are conducted on a model alumina coating containing laminar defect intralayers. Controlled subsurface damage introduced with a spherical indenter is observed using a presectioned specimen. Microcrack damage accumulates progressively with increasing contact load and number of cycles. Associated changes in thermal diffusivity, specifically in the through-thickness direction, are imaged and quantified point-by-point using laser-generated thermal waves. The effective thermal resistance of the coating increases with crack density, up to the point of failure.

Type
Articles
Copyright
Copyright © Materials Research Society 1996

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References

REFERENCES

1.Herman, H., Sci. Am. 256, 113188 (1988).Google Scholar
2.Herman, H., Mater. Res. Soc. Bull. 13, 6067 (1988).CrossRefGoogle Scholar
3.Herman, H., Berndt, C.C., and Wang, H., in Ceramic Films and Coatings, edited by Wachtman, J.B. and Haber, R. A. (Noyes Publications, Park Ridge, NJ, 1991), pp. 131188.Google Scholar
4.Pawlowski, L., The Science and Engineering of Thermal Spray Coatings (John Wiley, New York, 1995).Google Scholar
5.Anthony, T. R., Banholzer, W. F., Fleischer, J.F., Wei, L., Kuo, P. K., Thomas, R. L., and Pryor, R.W., Phys. Rev. B 42, 11041111 (1990).CrossRefGoogle Scholar
6.Wei, L. and Lawn, B. R., J. Mater. Res. 11, 939 (1996).CrossRefGoogle Scholar
7.Pajares, A., Wei, L., Lawn, B. R., Padture, N. P., and Berndt, C. C., Mater. Sci. Eng. A208, 158165 (1996).CrossRefGoogle Scholar
8.Pajares, A., Wei, L., Lawn, B. R., and Berndt, C. C., J. Am. Ceram. Soc. (in press).Google Scholar
9.Xu, H. H. K., Wei, L., Padture, N. P., Lawn, B. R., and Yeckley, R. L., J. Mater. Sci. 30, 869878 (1995).CrossRefGoogle Scholar
10.Grice, K. R., Inglehart, L. J., Favro, L. D., Kuo, P. K., and Thomas, R. L., J. Appl. Phys. 54, 62456255 (1983).CrossRefGoogle Scholar
11.Wei, L. and White, G. S., J. Mater. Res. (submitted).Google Scholar