Improved oxidation resistance of high emissivity coatings on fibrous ceramic for reusable space systems. (January 2019)

• Record Type: Journal Article
• Authors: Shao, Gaofeng; Lu, Yucao; Hanaor, Dorian A.H.; Cui, Sheng; Jiao, Jian; Shen, Xiaodong
• Is Part Of: Corrosion science. Volume 146(2019)
• Page Start: 233
• Page End: 246
• Publication Date: 2019-01
• Subjects: A. Glass -- A. Intermetallic -- B. XPS -- C. Oxidation -- C. Oxide coatings; Corrosion and anti-corrosives -- Periodicals; 620.11223
• DOI: 10.1016/j.corsci.2018.11.006
• Languages: English
• ISSNs: 0010-938X

Abstract

Highlights: WSi2 –MoSi2 based coatings were developed by rapid sintering method. Only 4.0% radiative loss in 1.27–1.73 μm occurs after oxidation at 1773 K for 50 h. The viscosity of the surface glass layer was characterized by XPS. The phenomena including defects formation and defects healing were revealed. The advantages of double phase metal silicides were discussed. Abstract: To develop high emissivity coatings on fibrous ceramic substrates with improved thermal resistance for reusable space systems, WSi2 –MoSi2 –Si–SiB6 -borosilicate glass coatings were prepared on fibrous ZrO2 by slurry dipping and subsequent high temperature rapid sintering. A coating with 20 wt% WSi2 and 50 wt% MoSi2 presents optimal thermal stability with only 10.06 mg/cm 2 mass loss and 4.0% emissivity decrease in the wavelength regime 1.27–1.73 μm after 50 h oxidation at 1773 K. The advantages of double phase metal-silicide coatings combining WSi2 and MoSi2 include improved thermal compatibility with the substrate and an enhanced glass-mediated self-healing ability.