F. Zok—contributing editor
Monazite Coatings on SiC Fibers II: Oxidation Protection
Article first published online: 2 OCT 2006
Journal of the American Ceramic Society
Volume 89, Issue 11, pages 3481–3490, November 2006
How to Cite
Mogilevsky, P., Boakye, E. E., Hay, R. S., Welter, J. and Kerans, R. J. (2006), Monazite Coatings on SiC Fibers II: Oxidation Protection. Journal of the American Ceramic Society, 89: 3481–3490. doi: 10.1111/j.1551-2916.2006.01241.x
This work was supported by the Air Force Research Laboratory, Materials and Manufacturing Directorate, under Contract No. F33615-01-C-5214.
- Issue published online: 2 OCT 2006
- Article first published online: 2 OCT 2006
- Manuscript No. 21320. Received January 4, 2006; accepted June 12, 2006
The effect of monazite on the oxidation of SiC was studied in laboratory and dry air. Monazite inhibited the oxidation of Tyranno-SA™, Tyranno-ZX™, Sylramic, and Hi-Nicalon SiC fibers. Oxidation of pure chemical vapor deposition SiC and undoped SiC single crystals was not inhibited by monazite. Dry oxidation of both uncoated and monazite-coated Tyranno-SA™ fibers initially displayed parabolic kinetics with an activation energy of 180–190 kJ/mol. Subsequently, the oxidation rate of monazite-coated fibers increased and the oxide-scale growth rate approached that of the uncoated fibers. No differences in the composition or structure of the silica oxidation product could be detected between uncoated and coated fibers using transmission electron microscopy and energy-dispersive spectroscopy. Possible mechanisms of the inhibition of SiC oxidation by monazite are discussed.