Abstract: A method of making a ceramic matrix composite that exhibits moisture and environmental resistance has been developed. The method includes depositing a diffusion barrier layer comprising boron nitride on silicon carbide fibers and depositing a moisture-tolerant layer comprising silicon-doped boron nitride on the diffusion barrier layer, where a thickness of the moisture-tolerant layer is from about 3 to about 300 times a thickness of the diffusion barrier layer. Thus, a compliant multilayer including the moisture-tolerant layer and the diffusion barrier layer is formed. A wetting layer comprising silicon carbide, boron carbide, and/or pyrolytic carbon is deposited on the compliant multilayer layer. After depositing the wetting layer, a fiber preform comprising the silicon carbide fibers is infiltrated with a slurry. After slurry infiltration, the fiber preform is infiltrated with a melt comprising silicon and then the melt is cooled, thereby forming a ceramic matrix composite.

Abstract: A method of making a ceramic matrix composite that exhibits chemical resistance has been developed. The method comprises depositing a compliant layer comprising boron nitride, silicon-doped boron nitride, and/or pyrolytic carbon on silicon carbide fibers, depositing a barrier layer having a high contact angle with molten silicon on the compliant layer, and depositing a wetting layer comprising silicon carbide, boron carbide, and/or pyrolytic carbon on the barrier layer. After depositing the wetting layer, a fiber preform comprising the silicon carbide fibers is infiltrated with a slurry. After slurry infiltration, the fiber preform is infiltrated with a melt comprising silicon, and then the melt is cooled, thereby forming a ceramic matrix composite.