1. In-situ reaction synthesis Al2O3 overlay modified 7YSZ TBC for NaCl hot corrosion
- Author
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Wo Jiang, Rong-Jiu Li, Yan-Qing Jiang, Junli Feng, Huan-Tao Chen, Kesong Zhou, Chunming Deng, Min Liu, Ju-Hang Yin, Bing He, Jia-Feng Fan, Xue-Shi Zhuo, Guo Liu, Shuangquan Guo, Yong-Jun Hu, and Xiaofeng Zhang
- Subjects
010302 applied physics ,Materials science ,Process Chemistry and Technology ,02 engineering and technology ,Chemical vapor deposition ,engineering.material ,021001 nanoscience & nanotechnology ,Microstructure ,01 natural sciences ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,Corrosion ,Thermal barrier coating ,Metal ,Coating ,visual_art ,0103 physical sciences ,Materials Chemistry ,Ceramics and Composites ,engineering ,visual_art.visual_art_medium ,Composite material ,0210 nano-technology ,Layer (electronics) ,Yttria-stabilized zirconia - Abstract
Thermal barrier coatings (TBCs) are facing the challenge of chloride salt hot corrosion in the marine environment. In the manuscript, 7YSZ feather-like columnar structure coatings were prepared by plasma spray-physical vapor deposition (PS-PVD). The Al2O3-modification based on in-situ synthesis was used as the strategy to improve the hot corrosion resistance of the coating. Then, the coatings were subjected to test of 900 °C NaCl thermal exposure and combustion gas-salt spray ablation. The microstructure and phase evolution results of the coatings show that NaCl has a strong corrosive effect on the as-sprayed PS-PVD TBC and leading to catastrophic oxidation. In contrast to this, the Al2O3-modified coating shows good corrosion resistance. In the hot corrosion behavior of NaCl, the metal elements in the bond layer are rapidly oxidized and accumulated on the surface of TGO layer through the electrochemical corrosion mechanism, which makes the TGO thicken rapidly. After combustion gas-salt spray corrosion, the YSZ coatings sintered and the evolution of mechanical properties were analyzed. Compared with the initial sprayed state, the hardness of the as-sprayed coating and the Al2O3-modified coating increased by 13.04 GPa and 11.47 GPa, respectively. And the elastic modulus of as-sprayed coating and Al2O3-modified coating increased by 133.00 GPa and 129.60 GPa, respectively.
- Published
- 2021