EBSD analysis of microstructure changes in YSZ coatings during thermal cycling
| Autor: | Yiling Huang, Yitian Shen, Xiang Guo, Yi Zeng, Jimei Zhang, Chucheng Lin, Xuemei Song |
|---|---|
| Rok vydání: | 2021 |
| Předmět: |
010302 applied physics
Materials science Scanning electron microscope Process Chemistry and Technology 02 engineering and technology Temperature cycling engineering.material 021001 nanoscience & nanotechnology Microstructure 01 natural sciences Surfaces Coatings and Films Electronic Optical and Magnetic Materials Thermal barrier coating Coating Residual stress 0103 physical sciences Materials Chemistry Ceramics and Composites engineering Composite material 0210 nano-technology Yttria-stabilized zirconia Electron backscatter diffraction |
| Zdroj: | Ceramics International. 47:5559-5569 |
| ISSN: | 0272-8842 |
| DOI: | 10.1016/j.ceramint.2020.10.140 |
| Popis: | Failure of atmospheric plasma sprayed (APS) yttria-stabilized zirconia (YSZ) coatings is complicated. Therefore, determining the microstructural changes that occur in the top coat during thermal cycling is beneficial to figure out the dominant failure mechanism in thermal barrier coatings. In this study, thermal cycling tests were conducted on YSZ coatings sprayed by APS. For comparison, coatings with the same spray parameters were held at 1100 °C for 25 h. Areas of interest in the cross-sections of the coatings were chosen prior to thermal cycling, in which ex-situ observation and analysis were performed via scanning electron microscope and electron backscatter diffraction. Residual stress values of coatings with different thermal cycling times were measured by X-ray diffraction. The growth of quasi-columnar crystals, which were related to a depletion in Al and an increase in stress, was observed. During thermal loading, the vertical cracks propagate comparatively easier leading to the spallation. The residual stress varies continually during the thermal cycling test and the changes are divided into several stages. The monoclinic phase transformation tends to occurred inside grains, creating compressive stress inside the coating, which improve the longevity of the coating. |
| Databáze: | OpenAIRE |
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