Isothermal oxidation of physical vapor deposited partially stabilized zirconia thermal barrier coatings
- 101 Downloads
Thermal barrier coatings (TBCs), consisting of physical vapor deposited (PVD) partially stabilized zirconia (PSZ, 8 wt.%Y2O3) and a diffusion aluminide bond coat, were characterized as a function of time after oxidative isothermal heat treatment at 1373 K in air. The experimental characterizations was conducted by X-ray diffraction analysis and scanning electron microscopy (SEM) with energy-dispersive spectroscopy. During cooling to room temperature, spallation of the PSZ ceramic coatings occurred after 200 and 350 h of isothermal heat treatment. This failure was always sudden and violent, with the TBC popping from the substrate. The monoclinic phase of zirconia was first observed on the bottom surface of the PVD PSZ after 200 h of isothermal heat treatment. The failure of TBCs occurred either in the bond coat oxidation products of αAl2O3 and rutile TiO2 or at the interface between the oxidation products and the diffusion aluminide bond coat or the PSZ coating.
Keywordsoxidation partially stabilized zirconia thermal barrier coating
Unable to display preview. Download preview PDF.
- 4.E.Y. Lee, R.R. Biederman, and R.D. Sisson Jr.,Metall. Sci., Vol 17, 1989, p 505Google Scholar
- 5.E.Y. Lee, R.R. Biederman, and R.D. Sisson Jr.,Plasma Surf. Eng., Vol 1, 1989, p 365Google Scholar
- 7.R.A. Miller, J.L. Smialek, and R.G. Garlick, Phase Stability in Plasma Sprayed Partially Stabilized Zirconia-Yttria,Adv. Ceram. III, Science and Technology of Zirconia, A.H. Heuer and L.W. Hobbs, Ed., American Ceramic Society, 1981, p 241–253Google Scholar
- 9.E.Y. Lee, R.R. Biederman, and R.D. Sisson, Jr., Modelling the Lifetimes of Thermal Barrier Coatings Based on the β-NiAl Phase Life in the Bond Coat,Proc. 1990 Coatings for Advanced Heat Engines Workshop, Office of Transportation Technology, Assistant Secretary for Conservation and Renewable Energy, U.S. Department of Energy, 1990, p 85–91Google Scholar
- 10.Y.H. Sohn, E.Y. Lee, and R.D. Sisson, Jr., Life Prediction and Life Extension of Thermal Barrier Coatings for Gas Turbine Engines,Proc. 1992 Coatings for Advanced Heat Engines Workshop, Office of Transportation Technology, Assistant Secretary for Conservation and Renewable Energy, U.S. Department of Energy, 1992, p11–60Google Scholar
- 13.Y.H. Sohn, M.S. thesis, Worcester Polytechnic Institute, Mechanical Engineering Dept., Worcester, MA, 1993Google Scholar