Investigation of Strontium-Niobium Oxides for Application to Thermal Barrier Coatings

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Abstract:

We have been trying to find new oxide compounds with large thermal expansion coefficients and low thermal conductivities by means of a material calculation technique. Among thousands of compounds in the databases, we found that there were some materials with low thermal conductivities and large thermal expansion coefficients in the group of strontium-niobium oxides. For example, Sr4Nb2O9 has a thermal expansion coefficient of 14.510-6 / and thermal conductivity of 1.0 W/mK, although a slight amount of other phases appear during long-term annealing. These thermal properties are better than those of yttria-stabilized zirconia, which is the standard material for thermal barrier coatings. To prevent the precipitation of other phases, we prepared the solid solutions, Sr4Nb2-xMxO9. In this study, the thermal conductivities and thermal expansion coefficients of these solid solutions were measured, and their thermal stabilities were evaluated by long-term annealing.

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Key Engineering Materials (Volumes 317-318)

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517-520

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August 2006

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© 2006 Trans Tech Publications Ltd. All Rights Reserved

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[1] R.A. Miller: Surf. Coat. Technol., 30(1) 1-11 (1987).

Google Scholar

[2] H. Kaneko, T. Torigoe, M. Mega, K. Takahashi, and D. Izutsu: J. Gas Turbine Soc. Jpn., 30(6) 514-18 (2002).

Google Scholar

[3] H. Matsubara: Ceramics Japan, 39(4) 275-80 (2004).

Google Scholar

[4] R. Vassen, X. Cao, F. Tietz, D. Basu, and D. Stöver: J. Am. Ceram. Soc., 83(8) 2023-28 (2000).

Google Scholar

[5] X. Cao, R. Vassen, W. Jungen, S. Schwartz, F. Tietz, and D. Stöver: J. Am. Ceram. Soc., 84(9) 2086-90 (2001).

Google Scholar

[6] J. Wu, X. Wei, N.P. Padture, P.G. Klemens, M. Gell, E. García, P. Miranzo, and M.I. Osendi: J. Am. Ceram. Soc., 85(12) 3031-35 (2002).

DOI: 10.1111/j.1151-2916.2002.tb00574.x

Google Scholar

[7] M.J. Maloney: Thermal Barrier Coating Systems and Materials, (U.S. Pat. No. 6117560, 2000).

Google Scholar

[8] H. Lehmann, D. Pitzer, G. Pracht, R. Vassen, D. Stöver: J. Am. Ceram. Soc., 86(8) 1338-44(2003).

Google Scholar

[9] I. Nagano, K. Akiyama, M. Shida, S. Ohta, and Y. Murakami: Trans. MRS-J, 29(2) 393-96 (2004).

Google Scholar

[10] K. Akiyama, I. Nagano, M. Shida: Ceramics Japan, 39(4) 300-02 (2004).

Google Scholar