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2692 |
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Wednesday, September 28, 2011, Saal A 11:00 AM Industrial Gas Turbines 1 |
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High temperature aging behavior and order-disorder transformation of plasma sprayed Sm2Zr2O7 coatings |
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Xinghua Zhong / Shanghai Institute of Ceramics, Chinese Academy of Sciences, P.R. China Jianhua Yu / Shanghai Institute of Ceramics, Chinese Academy of Sciences., China Huayu Zhao/ Shanghai Institute of Ceramics, Chinese Academy of Sciences., China Xiaming Zhou/ Shanghai Institute of Ceramics, Chinese Academy of Sciences., China Shunyan Tao*/ Shanghai Institute of Ceramics, Chinese Academy of Sciences., China Chuanxian Ding/ Shanghai Institute of Ceramics, Chinese Academy of Sciences., China |
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Rare-earth zirconates with a pyrochlore structure have attracted great attention for potential application in thermal barrier coating systems to further improve the performance and durability of gas turbines. In present work, the Sm2Zr2O7 coating was deposited by air plasma spraying technology, and its microstructure, phase composition and some properties including mechanical and thermo-physical properties were examined. The as-sprayed Sm2Zr2O7 coating exhibited a typical lamellar structure with well defined columnar grains in individual splat. Increasing heat treatment temperature resulted in decrease in the total porosity values, especially the interlamellar microcrack density of coatings. A defective fluorite-type structure was observed for the as-sprayed coating, which gradually transformed to pyrochlore structure with increasing heat treatment temperature. Their microhardness and elastic modulus increased after heat treatments. The thermal conductivity of as-sprayed Sm2Zr2O7 coatings was much lower than that of the heat treated one, and both of them were significantly lower than that of 8YSZ coatings treated under the same conditions. |