Microstructure evolution of HfB2-SiC/SiC coating for C/C composites during long-term oxidation at 1700 °C. (September 2022)

• Record Type: Journal Article
• Authors: Lv, Junshuai; Zhang, Yulei; Li, Wei; Zhu, Xiaofei; Li, Jiachen; Zhang, Jianhua; Li, Tao
• Is Part Of: Corrosion science. Volume 206(2022)
• Publication Date: 2022-09
• Subjects: Carbon/carbon composites -- Oxidation-resistant coatings -- HfB2 -- SiC -- Coating recession; Corrosion and anti-corrosives -- Periodicals; 620.11223
• DOI: 10.1016/j.corsci.2022.110524
• Languages: English
• ISSNs: 0010-938X

Abstract

Abstract: A rigorous understanding of the structural evolution of oxidation-resistant coatings in service can pave the way for the development of coatings for carbon/carbon composites, and therefore a typical HfB2 -SiC/SiC coating was investigated here. The initial oxidation of the coating resulted in a SiO2 /HfO2 scale, and the subsequent structural evolution was dominated by the growth of HfSiO4, forming a SiO2 /HfSiO4 /HfO2 protective layer that was stable at 1700 °C with long-term exposure to air. Ultimately, the SiC transition layer gradually degraded due to the active oxidation of SiC. Based on these findings, feasible strategies to improve coating longevity are proposed. Highlights: Effective HfB2 -SiC/SiC coating was fabricated by a readily implementable method. The coating can protect C/C composites in air at 1700 °C for 100 h. The structure evolution of the coating in service was investigated in-depth. Feasible strategies for further improving the coating longevity were proposed.