Microstructural evolution and degradation modes in cyclic and isothermal oxidation of an EB-PVD thermal barrier coating
| Autor: | Y. Renollet, F. Ibegazene-Ouali, R. Mevrel, C. Rio |
|---|---|
| Rok vydání: | 2000 |
| Předmět: |
Materials science
Mechanical Engineering Metallurgy Metals and Alloys Oxide Condensed Matter Physics Microstructure Isothermal process Thermal barrier coating Superalloy chemistry.chemical_compound chemistry Mechanics of Materials Materials Chemistry Ceramics and Composites Cubic zirconia Composite material Field emission gun Aluminide |
| Zdroj: | Materials at High Temperatures. 17:205-217 |
| ISSN: | 1878-6413 0960-3409 |
| Popis: | Thermal barrier coatings constituted of a partially stabilised zirconia layer (∼100 μm thick) deposited by EB-PVD on top of a platinum-modified aluminide bondcoat to protect a single crystal superalloy substrate, have been studied in cyclic and isothermal oxidation at 1,100°C in air. Close examination by high resolution SEM (with field emission gun) of the oxide scale and of the metallic surfaces after various durations, up to 600 hours at 1,100°C, show several morphological features which may affect the integrity of the systems: partial decohesion regions with large grain areas at the inner surface of the scale, subsequently replaced by a cellular morphology, cavities within the oxide scale as well as at the zirconia–alumina interface. The nature and distribution of these features depend on the type of test (isothermal or cyclic oxidation) and on the systems studied (standard superalloy or modified to lower the sulphur content). Scenarios are proposed to explain the observations reported. |
| Databáze: | OpenAIRE |
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