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.

Abstract: In some examples, an article may include a substrate and a coating on the substrate. In accordance with some of these examples, the coating may include a bond layer and an overlying layer comprising at least one oxide. In some examples, the bond layer comprises silicon metal and at least one of a transition metal carbide, a transition metal boride, or a transition metal nitride.

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: In some examples, an article may include a substrate and a coating on the substrate. The substrate may include a superalloy, a ceramic, or a ceramic matrix composite. The coating may include a layer comprising a matrix material and a plurality of nanoparticles. The matrix material may include at least one of silica, zirconia, alumina, titania, or chromia, and the plurality of nanoparticles may include nanoparticles including at least one of yttria, zirconia, alumina, or chromia. In some examples, an average diameter of the nanoparticles is less than about 400 nm.

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 braze material includes a first set of particles, a second set of particles, and a polymeric binder. The first set of particles includes a braze powder, where the braze powder comprises an Si-containing alloy. The first set of particles defines an average or median particle diameter between about 1 ?m and about 40 ?m. The second set of particles includes at least one of SiC or a transition metal carbide, where the second set of particles has a multimodal particle size distribution.

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: A method includes predicting a composition of calcium-magnesium-aluminum-silicate (CMAS) to be encountered by a high temperature mechanical system during use of the high temperature mechanical system. The method further includes selecting a composition of a CMAS-resistant barrier coating layer based at least in part on the predicted composition of CMAS. The CMAS-resistant barrier coating layer includes a base composition and at least one secondary oxide selected based on the predicted composition of CMAS. The at least one secondary oxide includes at least one of an oxide of a divalent element, an oxide of a trivalent element, or an oxide of a tetravalent element. The CMAS-resistant barrier coating layer comprises greater than 0 mol. % and less than about 7 mol. % of the at least one secondary oxide.

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: An assembly for a gas turbine engine includes ceramic material containing (i.e. ceramic matrix composite) segments and joints that couple the segments together.

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: A turbine shroud for a gas turbine engine includes an annular metallic carrier, a blade track, and a cross-key connection formed between the annular metallic carrier and the ceramic blade track. The cross-key connection is formed between the annular metallic carrier and inserts included in the blade track. The inserts are bonded to an annular runner also included in the blade track by a braze 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, an article may include a substrate and a coating on the substrate. The substrate may include a superalloy, a ceramic, or a ceramic matrix composite. The coating may include a first set of layers and a second set of layers. At least one layer of the first set of layers is between two layers of the second set of layers. The at least one layer of the first set of layers comprises one of amorphous silica or silicon nitride, and the at least two layers of the second set of layers comprises the other of amorphous silica or silicon nitride.

Abstract: An article having a substrate that includes a ceramic or a ceramic matrix composite, a bond layer on the substrate that includes silicon metal and a boria stabilizing agent, and at least one additional layer on the bond layer.

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: A turbine shroud for a turbine of a gas turbine engine is disclosed. The turbine shroud is configured to direct products of a combustion reaction in a combustor of the gas turbine engine toward a plurality of rotatable turbine blades of the turbine to cause the plurality of turbine blades to rotate.

Abstract: A barrier coating for isolating a metallic support component from a composite component in a gas turbine engine is provided. The barrier coating may be applied to the metallic support component so that when the ceramic component is mounted on the metallic support component the barrier coating is engaged.

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: An example article may include a component, a substrate including a first ceramic, a joining layer between the component and the substrate, and a joint surface coating between the substrate and the joining layer. The joint surface coating may include a diffusion barrier layer including a second ceramic material, and a compliance layer including at least one of a metal or a metalloid. An example technique may include holding a first joining surface of a coated component adjacent a second joining surface of a second component. The example technique may further include heating at least one of the coated component, the second component, and a braze material, and brazing the coated component by allowing the braze material to flow in a region between the first joining surface and the second joining surface.