Corrosion Science | 2019
Improved oxidation resistance of high emissivity coatings on fibrous ceramic for reusable space systems
Abstract
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\u2009wt% WSi2 and 50\u2009wt% MoSi2 presents optimal thermal stability with only 10.06\u2009mg/cm2 mass loss and 4.0% emissivity decrease in the wavelength regime 1.27–1.73\u2009μm after 50\u2009h oxidation at 1773\u2009K. 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.