Abstract: A seal includes a ceramic matrix composite ply having woven ceramic-based fibers in a ceramic-based matrix. The ceramic matrix composite ply has at least one bend formed about a bend axis and defines at least one rounded portion. A sealed assembly and a method of making a seal are also disclosed.

Abstract: A ceramic matrix composite includes a ceramic matrix, fibers embedded in the ceramic matrix, and an interfacial coating system on each of the fibers. The interfacial coating system includes alternating layers of boron nitride layers of individual thicknesses of about 50 nanometers to 200 nanometers and carbon layers of individual thicknesses of less than 5 nanometers.

Abstract: A ceramic matrix composite includes a plurality of ceramic fibers and an interface coating disposed on the plurality of ceramic fibers. The interface coating includes a carbon-based layer disposed on each ceramic fiber of the plurality of ceramic fibers and a boron-nitride based layer disposed on the first carbon-based layer. The ceramic matrix composite also includes a ceramic matrix surrounding the plurality of ceramic fibers. A ceramic matrix composite and a method of forming a ceramic matrix composite component are also disclosed.

Abstract: A chemical vapor deposition system comprises a reactor including at least one wall extending between an inlet end and an outlet end, and an internal volume defined by the at least one wall, the inlet end, and the outlet end. The reactor further comprises a heat source in thermal communication with the internal volume, and a solid precursor container removably placed within the internal volume. The solid precursor container includes at least one internal cavity for holding an amount of the solid precursor, and an opening fluidly connecting the at least one internal cavity to the internal volume of the reactor. The solid precursor comprises at least one of aluminum, zirconium, hafnium, and a rare earth metallic element.

Abstract: A method of making spherical gettering particles for an environmental barrier coating according to an exemplary embodiment of this disclosure, among other possible things includes spraying liquid preceramic polymer into a chamber via a nozzle to form liquid droplets, curing the liquid droplets to form spherical particles in the chamber, and converting the spherical particles to spherical ceramic gettering particles in a fluidized bed. A method of making spherical gettering particles for an environmental barrier coating and an article are also disclosed.

Abstract: A method of preparing a woven fabric material for use in a ceramic matrix composite includes passing a desized woven fabric tape having a first inter-filament spacing through a dispersal module configured to transform the desized woven fabric tape into a dispersed woven fabric tape having a second inter-filament spacing greater than the first inter-filament spacing. The dispersal module includes a first charging element with a charged surface and disposed to apply an electric charge to the desized woven fabric tape. The method further includes applying a polymer binder to the dispersed woven fabric tape to create a stabilized woven fabric tape having the second inter-filament spacing.

Abstract: A coated fiber structure for use in a ceramic matrix composite comprises a fiber and a coating system applied to and circumscribing the fiber. The coating system comprises an interface coating layer in direct contact with the fiber, the interface coating layer comprising one of boron nitride and a boron-doped pyrocarbon, at least one intermediate layer extending coaxially with and in direct contact with the interface layer, the at least one intermediate layer comprising at least one of silicon and boron nitride, and an outer layer extending coaxially with and in direct contact with the interface layer. At least one of the interface coating layer, the at least one intermediate layer, and the outer layer comprises a metallic element.

Abstract: Disclosed herein is a chemical vapor infiltration method including flowing ceramic precursors through a preform and depositing a matrix material on the preform at a first gas infiltration pressure, increasing the gas filtration pressure to a second gas infiltration pressure, and lowering the gas infiltration pressure to a third gas infiltration pressure which is intermediate to the first and second gas infiltration pressures.

Abstract: A method of forming a ceramic matrix composite component according to an exemplary embodiment of this disclosure, among other possible things includes laying up plies of ceramic reinforcement material with sacrificial plies to form a preform, infiltrating the preform with a ceramic matrix material, and machining away the sacrificial plies to reveal a surface profile of the ceramic matrix composite component. A preform for a ceramic matrix composite component is also disclosed.

Abstract: An airfoil includes an airfoil wall that defines a leading end, a trailing end, and pressure and suction sides that join the leading end and the trailing end. The airfoil wall includes a wishbone-shaped fiber layer structure that has a pair of arms that merge into a single leg. The pair of arms are formed by first and second S-shaped fiber layers each of which is comprised of a network of fiber tows. The first and second S-shaped fiber layers merge to form the single leg. The single leg comprises fiber tows from each of the first and second S-shaped fiber layers that are interwoven, and the single leg forms at least a portion of the trailing end of the airfoil wall.

Abstract: A method for manufacturing ceramic matrix composites (CMC) and CMCs made by the method are disclosed. The method can be a manual process or an automated process, such as using a robotic system, that is used for controlled delivery of ceramic particles in a CMC fabric. The method includes identifying voids present between adjacent tows of the CMC fabric and dispensing ceramic particles into the voids. Applying the ceramic particles in the center of the voids reduces the size and volume fraction of the voids/defects, improving the homogeneity of surface texture of the preform, homogeneity of microstructure, and part model shape conformity. The method for manufacturing CMCs creates CMCs having a homogenous distribution of small pores after matrix formation that improves the interlaminar mechanical and thermal properties of the CMCs.

Abstract: Disclosed herein is a chemical vapor infiltration method including flowing ceramic precursors through a preform and depositing a matrix material on the preform at a first gas infiltration pressure, increasing the gas filtration pressure to a second gas infiltration pressure, and lowering the gas infiltration pressure to a third gas infiltration pressure which is intermediate to the first and second gas infiltration pressures.

Abstract: A method of spreading fiber tows includes applying a coupling medium to a surface of a fibrous structure, positioning an ultrasonic probe adjacent to the surface of a fibrous structure, such that a tip of the ultrasonic probe is in contact with the coupling medium, moving at least one of the ultrasonic probe and the fabric structure relative to the other of the ultrasonic probe and the fibrous structure according to a first pattern, and imparting ultrasonic vibration with the ultrasonic probe to the surface of the fibrous structure while moving the ultrasonic probe along the surface of the fibrous structure. Imparting ultrasonic vibration to the surface of the fibrous structure spreads tows of the fibrous structure.

Abstract: A seal includes a ceramic matrix composite ply having woven ceramic-based fibers in a ceramic-based matrix. The ceramic matrix composite ply has at least one bend formed about a bend axis and defines at least one rounded portion. A sealed assembly and a method of making a seal are also disclosed.

Abstract: A method for forming a ceramic matrix composite component includes forming a fibrous preform of the component with a plurality of fiber layers and a fill region disposed between one or more of the plurality of fiber layers. Ceramic particles are provided in the fill region, which is densified using chemical vapor infiltration.

Abstract: A ceramic matrix composite includes a ceramic matrix, fibers embedded in the ceramic matrix, and an interfacial coating system on each of the fibers. The interfacial coating system includes alternating layers of boron nitride layers of individual thicknesses of about 50 nanometers to 200 nanometers and carbon layers of individual thicknesses of less than 5 nanometers.

Abstract: A method of manufacturing ceramic matrix composites includes producing chemical vapor deposition functionalized ceramic particles before injecting the functionalized ceramic particles into the CMC fabric. The functionalized ceramic particles are mixed with a binder solution and then dispensed into voids present between adjacent tows of the CMC fabric. Injecting the particles in the center of the voids reduces the size and volume fraction of the voids/defects, improving the homogeneity of surface texture, homogeneity of microstructure, and part model shape conformity.

Abstract: Disclosed is a coated composite comprising a seal coat disposed on a composite material wherein the seal coat comprises protective particles and a matrix.

Abstract: A method of preparing a woven fabric material for use in a ceramic matrix composite includes passing a desized woven fabric tape having a first inter-filament spacing through a dispersal module configured to transform the desized woven fabric tape into a dispersed woven fabric tape having a second inter-filament spacing greater than the first inter-filament spacing. The dispersal module includes a first charging element with a charged surface and disposed to apply an electric charge to the desized woven fabric tape. The method further includes applying a polymer binder to the dispersed woven fabric tape to create a stabilized woven fabric tape having the second inter-filament spacing.

Abstract: A method of preparing a woven ceramic fabric for use in a ceramic matrix composite includes transforming a woven fabric sheet having a first tow architecture into a separated woven fabric sheet having a second tow architecture, the first tow architecture including a plurality of warp tows and a plurality of weft tows, and the second tow architecture including a plurality of warp subtows and/or a plurality of weft subtows. Transforming the woven fabric sheet includes separating at least some of the plurality of warp tows and/or the plurality of weft tows into a greater number of corresponding warp subtows and/or weft subtows, respectively, such that second tow architecture includes more warp subtows and/or weft subtows than the first tow architecture comprises warp tows and weft tows, and wherein each of the warp subtows and/or weft subtows includes fewer filaments than corresponding warp tow and/or weft tow.