PLASMA THERMAL BARRIER COATINGS BASED ON ZIRCONIUM DIOXIDE WITH HIGH THERMAL STABILITY
Abstract
The paper presents optimization of processes for obtaining maximum content of tetragonal phase in the initial material and thermal barrier coatings (TBC) based on zirconium dioxide and hafnium oxide. Results of the investigations on phase composition of oxide HfO2 – ZrO2 – Y2O3 system have been given in the paper. The system represents a microstructure which is similar to zirconia dioxide and transformed for its application at 1300 °C. The paper explains a mechanism of hafnium oxide influence on formation of the given microstructure. The research methodology has been based on complex metallography, X – ray diffraction and electron microscopic investigations of structural elements of the composite plasma coating HfO2 – ZrO2 – Y2O system.
In order to stabilize zirconium dioxide dopant oxide should not only have an appropriate size of metal ion, but also form a solid solution with the zirconia. This condition severely limits the number of possible stabilizers. In fact, such stabilization is possible only with the help of rare earth oxides (Y2O3, Yb2O3, CeO2, HfO2). Chemical purity of the applied materials plays a significant role for obtaining high-quality thermal barrier coatings. Hafnium oxide has been selected as powder for thermal barrier coatings instead of zirconium dioxide due to their similarities in structural modification, grating, chemical and physical properties and its high temperature structural transformations. It has been established that plasma thermal barrier HfO2 – ZrO2 – Y2O3 coatings consist of one tetragonal phase. This phase is equivalent to a non-equilibrium tetragonal t' phase in the “zirconium dioxide stabilized with yttrium oxide” system. Affinity of Hf+4 and Zr+4 cations leads to the formation of identical metastable phases during rapid quenching.
About the Authors
O. G. Devoino
Belarusian National technical University
Belarus
Belarus
Professor, PhD in Engineering
V. V. Okovity
Belarusian National technical University
Belarus
Graduate student
Belarus
Graduate student
References
1. Ilyushchenko, A. F., Ivashko, V. S., Okovityi, V. A., Sobolevskii, S. B.(1998). Thermal barrier coatings on ZrO2 basis. Minsk, Remika, 128 p. (in Russian).
2. Khor, K. A., Gu, Y. W., Dong, Z. L. (2000). Properties of Plasma Sprayed Functionally Graded YSZ / NiCoCr AlY Composite Coatings. Thermal Spray 2000: Surface Engineering via Applied Research: Proceedings of the 1st International Thermal Spray Conference. Kobe, Japeny, 1241–1248.
3. Porter, D. L, Heuer, H. (2006). Mechanisms of Toughening Partially Stabilized Zirconia (PS2). Journal of the American Ceramic Society, 6 (3), 183–184. doi: 10.1111/j.1151-2916.1977.tb15509.x
4. Singheiser, L. (1998). The Performance of High Temperature Corrosion Resistant Coatings on Superalloyes Nuclear Extended Laboratory Tests. 1st Plasma Technic. Symposium Lucerne, 2, 164–173.
5. Robert, M. (1997). Microstructural Evolution in Co-P37 and the Room Temperature Instability of Tetragonal ZrO2. The Amer. Ceram. Soc., 10 (4), 214–220.
6. Okovity, V. A. (1998). Influence of technological parameters of TBC ceramic layer on resistance to thermal cycling. Poroshkovoya Metalurgia. Respublikanskii mezhvedomstvennyi sbornik nauchnykh trudov [Powder Metallurgy. Republican Interdepartmental Collection of Research Papers]. Minsk, 21, 101–105 (in Russian).
7. Okovity, V. A. (2005). Development of thermal barrier plasma coatings. Svarka i rodstvennye tekhnologii [Welding and Related Technologies], 7, 80–82 (in Russian).
8. Okovity, V. A. (2007). Optimization of ZrO2 – Y2?3 depositing process. Poroshkovoya Metalurgia. Respublikanskii mezhvedomstvennyi sbornik nauchnykh trudov [Powder Metallurgy. Republican Interdepartmental Collection of Research Papers]. Minsk, 30, 245–249 (in Russian).
9. Il'iushchenko, A. F., Okovityi, V. A., Gromyko, G. F., Shevtsov, A. I., Panteleenko, F. I., Matsuka, N. P., Okovityi, V. V. (2009). Mathematical model of thermal processes occurring during formation of ZrO2-based coatings. Poroshkovoya Metalurgia. Respublikanskii mezhvedomstvennyi sbornik nauchnykh trudov [Powder Metallurgy. Republican Interdepartmental Collection of Research Papers]. Minsk, 32, 9–20 (in Russian).
10. Il'iushchenko, A. F., Kusin, R. A., Cherniak, I. N., Kusin, A. R., Zhegzdrin', D. I., Manoilo, E. D., Kaptsevich, V. M. (2011). Simulation of pore formation while developing thermal barrier coatings on the basis of zirconium dioxide. Poroshkovoya Metalurgia. Respublikanskii mezhvedomstvennyi sbornik nauchnykh trudov [Powder Metallurgy. Republican Interdepartmental Collection of Research Papers]. Minsk, 34, 36–40 (in Russian)
11. Okovityi, V. A., Panteleenko, F. I., Devoino, O. G., Okovityi, V. V., Sobolevskii, S. B., Shevtsov, A. I. (2011). Development of gradient plasma coatings on the basis of zirconium dioxide stabilized with yttrium oxide. Vestnik BNTU [Bulletin of the Belarusian National Technical University], 6, 5–9.
12. Ilyushchenko, A. F., Okovityi, V. A., Kundas, S. P., Formanek, B. (2002). Formation of gas and thermal coatings: theory and practice. Minsk, Besprint. 480 p. (in Russian).
13. Ilyushchenko, A. F., Okovity, V. A. Shevtsov, A. I (2006). Plasma coatings on the basis of ceramic materials. Minsk, Besprint. 316 p. (in Russian).
14. Padovan, J. (2007). Thermo-mechanical behaviour of plasma-sprayed HfO2 – Y2O3 coatings. Ceram. Eng. And Sci., 8, 27–38.
15. Alperine, S., Lelait, L. (1994). Microstructural Investigation of Plasma Sprayed Yttria Partially Stabilized Zirconia TBC. J. Eng. Gas Turbines Power, 116 (1), 258-265 doi:10.1115/1.2906802.
16. Alperine, S., Lelait, L. (1991). TEM Investigations of High Toughness Non-Equilibrium Phases in the ZrO2 – Y2O3 System. Scripta Metallurgica et Materiala, 25 (8), 1815–1820 doi: 10.1016/0956-716X(91)90310-W
17. Lelait, L. (1991). Etude microstructurale fine de revêtements céramiques du type barrière thermique: incidence sur la résistance thermomécanique de ces revêtements. [Microstructural study of thermal barrier coating application of the thermomechanical resistance of this coating. PhD thesis]. Université Paris-Sud (U.F.R. d'Orsay), France. (in French)
18. Ibegazene, H., Alperine, S., Diot, C. (1995). Yttria Stabilized Hafnia-Zirconia Thermal Barrier Coatings: influence of hafnia addition on TBC structure and high temperature behavior. Journal of Materials Science, 30 (4), 938-951.
Review
For citations:
Devoino O.G., Okovity V.V. PLASMA THERMAL BARRIER COATINGS BASED ON ZIRCONIUM DIOXIDE WITH HIGH THERMAL STABILITY. Science & Technique. 2015;(1):35-39. (In Russ.)
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