An article has a substrate and a layer atop the substrate. The layer has: a matrix comprising at least one of hafnium silicate (HfSiO.sub.4) and ytterbium disilicate (Yb.sub.2Si.sub.2O.sub.7); and barium magnesium alumino silicate (BMAS).

The present invention describes various methods for manufacturing gel composite sheets using segmented fiber or foam reinforcements and gel precursors. Additionally, rigid panels manufactured from the resulting gel composites are also described. The gel composites are relatively flexible enough to be wound and when unwound, can be stretched flat and made into rigid panels using adhesives.

The present invention describes various methods for manufacturing gel composite sheets using segmented fiber or foam reinforcements and gel precursors. Additionally, rigid panels manufactured from the resulting gel composites are also described. The gel composites are relatively flexible enough to be wound and when unwound, can be stretched flat and made into rigid panels using adhesives.

In some examples, techniques of repairing and/or reinforcing oxide-oxide ceramic matrix composite (CMC) materials using a metallic material. In one example, a method including applying a metallic material at an edge of an oxide-oxide CMC substrate; and heating the metallic material to diffuse the metal material into the oxide-oxide CMC substrate at the edge. In another example, a method including applying a metallic material onto a damaged area of the oxide-oxide CMC; applying a reinforcing phase material onto the damaged area of the oxide-oxide CMC; and heating the metallic material to diffuse the metallic material into the oxide-oxide CMC and attach the reinforcing phase material to the damaged area of the oxide-oxide CMC.

In some examples, techniques of repairing and/or reinforcing oxide-oxide ceramic matrix composite (CMC) materials using a metallic material. In one example, a method including applying a metallic material at an edge of an oxide-oxide CMC substrate; and heating the metallic material to diffuse the metal material into the oxide-oxide CMC substrate at the edge. In another example, a method including applying a metallic material onto a damaged area of the oxide-oxide CMC; applying a reinforcing phase material onto the damaged area of the oxide-oxide CMC; and heating the metallic material to diffuse the metallic material into the oxide-oxide CMC and attach the reinforcing phase material to the damaged area of the oxide-oxide CMC.

An article may include a substrate including a ceramic or a ceramic matrix composite. The substrate defines a hot side surface configured to face a heated gas environment and a cool side surface opposite the hot side surface. The article also includes a cool side coating on the cool side surface. The cool side coating comprises at least one material having a flow temperature equal to or slightly less than a temperature of the heated gas environment.

An article may include a substrate including a ceramic or a ceramic matrix composite. The substrate defines a hot side surface configured to face a heated gas environment and a cool side surface opposite the hot side surface. The article also includes a cool side coating on the cool side surface. The cool side coating comprises at least one material having a flow temperature equal to or slightly less than a temperature of the heated gas environment.

A process for manufacturing a composite part includes introducing an adhesion promoter into the pores of a fibrous preform formed by threads covered with a coating having OH groups on its surface, the adhesion promoter including an electron-withdrawing group G1 that is reactive according to a reaction of substitution or of nucleophilic addition with the OH groups, and a reactive group G2; grafting the adhesion promoter to the surface of the coating by a reaction of substitution or nucleophilic addition of the OH groups on the group G1; introducing a ceramic precursor resin into the pores of the fibrous preform; polymerizing the resin introduced and bonding the grafted adhesion promoter to the resin by chemical reaction between these two compounds at the level of the group G2, and forming a ceramic matrix phase in the pores of the fibrous preform by pyrolysis of the polymerized resin.

A component for use in a gas turbine engine is made from ceramic materials. The component is made from a core preform containing ceramic reinforcement fibers. A plurality of preform tows are applied on at least a portion of the core preform and extend along at least a portion of the core preform to provide an outermost surface. The core preform and the plurality of preform tows are infiltrated with ceramic matrix material to form a ceramic matrix composite component.

A process for manufacturing a composite part includes introducing an adhesion promoter into the pores of a fibrous preform formed by threads covered with a coating having OH groups on its surface, the adhesion promoter including an electron-withdrawing group G1 that is reactive according to a reaction of substitution or of nucleophilic addition with the OH groups, and a reactive group G2; grafting the adhesion promoter to the surface of the coating by a reaction of substitution or nucleophilic addition of the OH groups on the group G1; introducing a ceramic precursor resin into the pores of the fibrous preform; polymerizing the resin introduced and bonding the grafted adhesion promoter to the resin by chemical reaction between these two compounds at the level of the group G2, and forming a ceramic matrix phase in the pores of the fibrous preform by pyrolysis of the polymerized resin.