Thermal shock behavior of a 8YSZ/CoCrAlYTaSi thermal sprayed barrier coating on GH202 superalloy
| Autor: | Bocheng Jiang, Keke Gao, Jiangdong Cao, Xue yu Cao |
|---|---|
| Rok vydání: | 2020 |
| Předmět: |
010302 applied physics
Thermal shock Materials science Scanning electron microscope Process Chemistry and Technology 02 engineering and technology engineering.material 021001 nanoscience & nanotechnology Microstructure 01 natural sciences Surfaces Coatings and Films Electronic Optical and Magnetic Materials Thermal barrier coating Superalloy Coating Transmission electron microscopy 0103 physical sciences Scanning transmission electron microscopy Materials Chemistry Ceramics and Composites engineering Composite material 0210 nano-technology |
| Zdroj: | Ceramics International. 46:7489-7498 |
| ISSN: | 0272-8842 |
| Popis: | The thermal shock behavior of a thermal barrier coating (TBC) prepared by plasma spraying at 1100 °C was investigated. The TBC consisted of a double layer structure of 8YSZ/CoCrAlYTaSi. The morphology, microstructure, phases and the elemental distribution of the TBCs were characterized using scanning electron microscopy (SEM), transmission electron microscope (TEM), scanning transmission electron microscope (STEM), X-ray diffraction (XRD) and electron probe micro-analysis (EPMA). The characterization results showed that the film consisted primarily of metastable tetragonal phases (t′), and a large number of micro-cracks were present in the 8YSZ crystals. Following eighty-six thermal shock cycles of the specimens a large areal spallation was observed on the 8YSZ coating. The decreased concentration of yttrium at the coating interfaces weakened the inhibition of crystal growth and the phase transition of the Al2O3. The growth of TGO (Thermal growth oxide) and the diffusion into the 8YSZ coating produced deformation and stress in the ceramic coating. Tantalum appeared to absorb the oxygen that diffused into the coatings and delayed the growth of TGO in the interface between the CoCrAlYTaSi and substrate, which was beneficial to prolonging the life of the TBC. |
| Databáze: | OpenAIRE |
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