A Method for Coating Fibers in Oxide Composites

A method for applying monazite coatings onto oxide fibers after matrix infiltration and sintering is devised and demonstrated. It uses an intermediate fugitive coating, followed by impregnation and pyrolysis of a monazite precursor solution. Composites with monazite coatings produced in this manner as well as those with only a fugitive coating exhibit superior mechanical performance to composites without any coating, as manifested in higher notched strength and fracture energy as well as significantly greater amounts of fiber pullout.