Al-modified environmental barrier coatings for protection against water vapor corrosion

• Published in: Corrosion science Vol. 217; p. 111123
• Main Authors: Zhuo, Xueshi, Wang, Chao, Wang, Meng, Wu, Jian, Zhang, Xiaofeng, Cui, Jianlei, Mei, Xuesong, Fan, Zhengjie
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.06.2023
• Subjects: Al-modified layer; Environmental barrier coatings; Oxidation; Water vapor corrosion; Yb3Al5O12; Environmental barrier coatings; Yb3Al5O12; Water vapor corrosion; Oxidation; Al-modified layer
• ISSN: 0010-938X; 1879-0496
• DOI: 10.1016/j.corsci.2023.111123

High-temperature water vapor corrosion is a great challenge for long lifetime of Si/mullite/Yb2SiO5 Environmental Barrier Coatings. In this work, the Yb3Al5O12 modified layer was in-situ synthesized on the surface of Yb2SiO5 layer to improve the steam resistance. The reaction mechanism of the Al-modified layer was explored. The steam corrosion experimental results indicated that the defects in Yb2SiO5 layer healed, and the oxidation rate of Si-bonded coating was slowed down under the protection of modified layer. Additionally, the calculation results of first-principle molecular dynamics confirmed that Yb3Al5O12 has excellent steam corrosion resistance. [Display omitted] •A protective layer was prepared on the surface of the Yb2SiO5 coating through the Al-modification method.•The reaction of Yb3Al5O12 with water vapor needs to break through a higher energy barrier than that of Yb2O3 and Yb2SiO5 at 1400 ℃.•The Al-modified EBCs exhibited excellent water vapor corrosion resistance due to the formation of a new Yb3Al5O12 phase as well as the healing of voids and microcracks in the Yb2SiO5 coating.