Effect of water vapour on preferential orientation of thermally grown oxide at 1050 °C. (December 2022)

• Record Type: Journal Article
• Authors: Li, Chao; Li, Dingjun; Yuan, Xiaohu; Song, Peng; Feng, Jing; Huang, Taihong; Lu, Jiansheng
• Is Part Of: Corrosion science. Volume 209(2022)
• Publication Date: 2022-12
• Subjects: Thermal Barrier Coating -- Electron Backscattering Diffraction -- Nanoindentation -- Thermally Grown Oxide -- Grain Orientation; Corrosion and anti-corrosives -- Periodicals; 620.11223
• DOI: 10.1016/j.corsci.2022.110737
• Languages: English
• ISSNs: 0010-938X

Abstract

Abstract: The crystal structure and hardness of thermally grown oxide (TGO) layer formed on a NiCoCrAlY bond coat in thermal barrier coatings (TBCs) prepared by electron-beam physical vapor deposition were studied. The hardness and the relationship between the crystal structure and defects depended on the oxidising atmosphere. The presence of excess water vapour during high-temperature oxidation promoted the transformation of δ- to α-Al2 O3 . The TGO layer formed in water vapour environments exhibited higher hardness and fewer defects than that formed in air. These results offer an opportunity to design the long-lifetime TBCs. Furthermore, the grain orientation of the TGO layer was affected by the presence of water vapour; the preferential orientation of alumina was < 0 0 1 > in air + water vapour environment. Graphical Abstract: ga1