Isothermal oxidation of physical vapor deposited partially stabilized zirconia thermal Barrier coatings

• Published in: Journal of materials engineering and performance 1994-02, Vol.3 (1), p.55-60
• Main Authors: SOHN, Y. H, BIEDERMAN, R. R, SISSON, R. D
• Format: Article
• Language: English
• Subjects: 360202 - Ceramics, Cermets, & Refractories- Structure & Phase Studies; 360205 - Ceramics, Cermets, & Refractories- Corrosion & Erosion; ALUMINIUM COMPOUNDS; ALUMINIUM OXIDES; CHALCOGENIDES; CHEMICAL REACTIONS; COATINGS; CORROSION PRODUCTS; Cross-disciplinary physics: materials science; rheology; CRYSTAL-PHASE TRANSFORMATIONS; DATA; Exact sciences and technology; EXPERIMENTAL DATA; FAILURES; HEAT TREATMENTS; INFORMATION; MATERIALS SCIENCE; MICROSTRUCTURE; NUMERICAL DATA; OXIDATION; OXIDES; OXYGEN COMPOUNDS; PHASE TRANSFORMATIONS; Physics; Surface treatments; TITANIUM COMPOUNDS; TITANIUM OXIDES; TRANSITION ELEMENT COMPOUNDS; VAPOR DEPOSITED COATINGS; YTTRIUM COMPOUNDS; YTTRIUM OXIDES; ZIRCONIUM COMPOUNDS; ZIRCONIUM OXIDES
• ISSN: 1059-9495; 1544-1024
• DOI: 10.1007/BF02654499

Thermal barrier coatings (TBCs), consisting of physical vapor deposited (PVD) partially stabilized zirconia (PSZ, 8 wt.% Y[sub 2]O[sub 3]) and a diffusion aluminide bond coat, were characterized as a function of time after oxidative isothermal heat treatment at 1,373 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 [alpha]Al[sub 2]O[sub 3] and rutile TiO[sub 2] or at the interface between the oxidation products and the diffusion aluminide bond coat or the PSZ coating.