Abstract: One aspect of the present disclosure includes a turbine vane assembly comprising a vane made from ceramic matrix composite material having an outer wall extending between a leading edge and a trailing edge and between a first end and an opposing second end; an endwall made at least partially from a ceramic matrix composite material configured to engage the first end of the vane; and a retaining region including corresponding bi-cast grooves formed adjacent the first end of the vane and a receiving aperture formed in the endwall; wherein a bond is formed in the retaining region to join the vane and endwall together.

Abstract: A method may include oxidizing a surface of a silicon-containing substrate to form a layer including silica on the surface of the silicon-containing substrate. The method also may include depositing, from a slurry including at least one rare earth oxide, a layer including the at least one rare earth oxide on the layer including silicon. The method additionally may include heating at least the layer including silica and the layer including the at least one rare earth oxide to cause the silica and the at least one rare earth oxide to react and form a layer including at least one rare earth silicate.

Abstract: A multilayer interface coating for composite material fibers includes a first coating layer deposited onto a fiber and a second coating layer deposited onto the first coating layer.

Abstract: A method of forming a composite article includes impregnating an inorganic fiber preform with a slurry composition. The slurry composition includes a particulate, a solvent, and a pre-gellant material. Gelling of the pre-gellant material in the slurry composition is initiated to immobilize the particulate and yield a gelled article, and substantially all solvent is removed from the gelled article to form a green composite article. The green composite article is then infiltrated with a molten infiltrant to form the composite article.

Abstract: In some examples, the disclosure describes an article and a method of making the same that includes a substrate including a ceramic or a ceramic matrix composite including silicon carbide, where the substrate defines an outer substrate surface and a plurality of grooves formed in the outer substrate surface, where each respective groove of the plurality of grooves exhibits an anchor tooth that spans an edge of the respective groove, and where the plurality of grooves define an average groove width less than about 20 micrometers, and a coating formed on the outer surface of the substrate, where the coating at least partially fills the plurality of grooves of the substrate.

Abstract: A method of forming a composite article includes impregnating an inorganic fiber preform with a slurry composition. The slurry composition includes a particulate, a solvent, and a pre-gellant material. Gelling of the pre-gellant material in the slurry composition is initiated to immobilize the particulate and yield a gelled article, and substantially all solvent is removed from the gelled article to form a green composite article. The green composite article is then infiltrated with a molten infiltrant to form the composite article.

Abstract: In some examples, method including forming an EBC layer on a substrate, wherein the EBC layer exhibits an initial porosity; forming a layer of silicate glass on a surface of the EBC layer; and melting the silicate glass on the surface of the EBC layer to infiltrate the EBC layer with the molten silicate glass to decrease the porosity of the EBC layer from the initial porosity to a final porosity.

Abstract: A method of forming a ceramic matrix composite are described herein. The method may include infiltrating a fiber preform with a solution comprising a refractory precursor in solution with a solvent. The refractory precursor may include a compound having at least one refractory metal element. The method may further include removing the solvent from the fiber preform, and reducing the refractory precursor to form a refractory metal that includes the refractory metal element.

Abstract: A ceramic matrix composite component and methods of making are described herein. The ceramic matrix composite may include a silicon containing matrix and refractory fibers embedded within the silicon containing matrix. The ceramic matrix composite component may further include a silicide layer sandwiched between the silicon containing matrix and the refractory fibers. A method of forming a ceramic matrix composite may include infiltrating a fluid that includes a refractory metal element containing compound into a fiber preform that includes fibers. The method may further include depositing the refractory metal element from the refractory metal element containing compound onto the fibers and forming, from the refractory metal element deposited onto the fibers, a refractory metal silicide.

Abstract: Integrated ceramic matrix composite components for use in gas turbine engines are disclosed along with methods for making the same. The methods include coinfiltrating a greenbody assembly with ceramic matrix to produce an integrated component.

Abstract: An assembly comprising a ceramic matrix composite component, a ceramic insert, and a ply and a method for producing the same. The ceramic matrix composite component may comprise silicon carbide fibers in a silicon carbide matrix. The ceramic inset may be adjacent to the ceramic matrix composite component. The ply may at least partially cover the ceramic insert such that the ceramic insert may be sandwiched between the ply and the ceramic matrix composite component, and the ply may extend beyond the ceramic insert in at least one direction so that the ply is joined to the ceramic matrix composite. The ply may comprise at least one layer of silicon carbide fibers or carbon fibers in a silicon carbide matrix.

Abstract: An assembly comprising a structural component and a sacrificial layer, and method for producing the same. The structural component may comprise silicon carbide fibers within a silicon carbide matrix. The sacrificial layer may be joined to the structural component and may comprising unarranged ceramic fibers, wherein the sacrificial layer may comprise a volume fiber fraction lower than a volume fiber fraction of the structural component.

Abstract: An assembly comprising a ceramic matrix composite component, a monolithic insert, and a polymer char and a method for producing the same. The ceramic matrix composite component may include an exterior surface, with the monolithic insert bonded to the exterior surface of the ceramic matrix composite component. The polymer char may be sandwiched between the monolithic insert and the exterior surface of the ceramic matrix composite that may bond the monolithic insert to the ceramic matrix composite component.

Abstract: A ceramic matrix composite component and a ceramic insert, and a method for producing the same. The ceramic matrix composite component may include an exterior surface comprising silicon fibers in a silicon carbide matrix. The insert may include a continuous porosity bonded to the exterior surface of the ceramic matrix composite component. The silicon carbide matrix of the ceramic matrix composite component may extend into the porosity of the ceramic insert to bond the ceramic insert to the ceramic matrix composite component.

Abstract: The disclosure describes techniques for joining a first part including a ceramic or a CMC and a second part including a ceramic or a CMC using brazing. A technique may include positioning a filler material in a joint region between the first and second parts and a metal or alloy on a bulk surface of the filler material. The metal or alloy may be locally heated to melt the metal or alloy, which may infiltrate the filler material. A constituent of the molten metal or alloy may react with a constituent of the filler material to join the first and second parts. Another technique may include depositing a powder that includes the filler material and the metal or alloy in the joint region. Substantially simultaneously with depositing the powder, the powder may be locally heated. A constituent of the molten metal or alloy may react with a constituent of the filler material to join the first and second parts.

Abstract: An article may include a substrate including a ceramic or a CMC; a bond layer on the substrate; and a diffusion barrier layer between the substrate and the bond layer. The diffusion barrier layer may include at least one of molybdenum metal, tantalum metal, tungsten metal, or niobium metal. In some examples, the article may include a stabilizing layer that includes at least one of a silicide of molybdenum (MoSi2), tantalum (TaSi2), tungsten (WSi2), or niobium (NbSi2), between the diffusion barrier layer and the bond layer.

Abstract: In some examples, a method including positioning a first ceramic or ceramic matrix composite (CMC) part and a second ceramic or CMC part adjacent to each other to define a joint between adjacent portions of the first ceramic or CMC part and the second ceramic or CMC part; and depositing an aqueous braze paste at least one of in the joint or adjacent the joint, wherein the aqueous braze paste comprises water, a water-soluble polymeric binder, and a silicon-based powder alloy.

Abstract: A method of forming a ceramic matrix composite are described herein. The method may include infiltrating a fiber preform with a solution comprising a refractory precursor in solution with a solvent. The refractory precursor may include a compound having at least one refractory metal element. The method may further include removing the solvent from the fiber preform, and reducing the refractory precursor to form a refractory metal that includes the refractory metal element.

Abstract: An article includes an abradable ceramic coating with an arrangement of features selected such that the coating has a porosity of about 5% to about 90%.

Abstract: A method may include positioning a multilayer braze tape at a joint between a first part comprising a ceramic or CMC and a second part comprising at least one of a ceramic, a CMC, a metal, or an alloy. The multilayer braze tape may include at least one layer comprising a silicon-containing braze material and at least one layer comprising a reinforcement material. The method also may include applying pressure to compress the multilayer braze tape between the first part and the second part, and heating the multilayer braze tape to melt the silicon-containing braze material and join the first part and the second part.