Impedance Analysis of 7YSZ Thermal Barrier Coatings During High-Temperature Oxidation
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- 作者：Wen-Long Chen ; Min Liu ; Ji-Fu Zhang
- 关键词：high ; temperature oxidation ; impedance spectroscopy ; thermal barrier coatings ; TGO
- 刊名：Journal of Thermal Spray Technology
- 出版年：2016
- 出版时间：December 2016
- 年：2016
- 卷：25
- 期：8
- 页码：1596-1603
- 全文大小：
- 刊物类别：Chemistry and Materials Science
- 刊物主题：Surfaces and Interfaces, Thin Films; Tribology, Corrosion and Coatings; Characterization and Evaluation of Materials; Operating Procedures, Materials Treatment; Analytical Chemistry;
- 出版者：Springer US
- ISSN：1544-1016
- 卷排序：25
文摘
ZrO2-7 wt.%Y2O3 (7YSZ) thermal barrier coatings (TBCs) were prepared by atmospheric plasma spraying. High-temperature oxidation of 7YSZ TBCs was accomplished at 950 °C and characterized by impedance spectroscopy and scanning electron microscopy with energy-dispersive spectrometry. The results indicated that the thermally grown oxide (TGO) mainly contained alumina. The increase of the thickness of the TGO layer appeared to follow a parabolic law. Impedance analysis demonstrated that the resistance of the TGO increased with increasing oxidation time, also following a parabolic law, and that characterization of the TGO thickness based on fitting an equivalent circuit to its measured resistance is feasible. The YSZ grain-boundary resistance increased due to increasing cracks within the coating for oxidation time less than 50 h. However, beyond 150 h, the YSZ grain-boundary resistance slightly decreased, mainly due to sintering of the coating during the oxidation process.