C04B2235/5244

Mitigating pyrophoric deposits during SiC CVI/CVD processes by introducing a mitigation agent into an exhaust conduit downstream of a reaction chamber

Systems for and methods of manufacturing a ceramic matrix composite include introducing a gaseous precursor into an inlet portion of a reaction furnace having a chamber comprising the inlet portion and an outlet portion that is downstream of the inlet portion, and delivering a mitigation agent, such as water vapor or ammonia, into an exhaust conduit in fluid communication with and downstream of the outlet portion of the reaction chamber so as to control chemical reactions occurring with the exhaust chamber. Introducing the gaseous precursor densifies a porous preform, and introducing the mitigation agent shifts the reaction equilibrium to disfavor the formation of harmful and/or pyrophoric byproduct deposits within the exhaust conduit.

HIGH TEMPERATURE COMPOSITE MATERIALS WITH EROSION RESISTANT SEAL COAT
20230027473 · 2023-01-26 ·

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

SYSTEM AND METHOD FOR COATING CERAMIC FIBER

A system for coating ceramic fibers for use in manufacturing a ceramic matric composite (CMC) article includes a frame having a plurality of frame members arranged so as to create a void therebetween. At least one of frame members includes a hollow body and at least one perforated hole defined in the hollow body. Thus, the ceramic fibers are securable at respective ends of the frame and extend across the void. The frame also includes an inlet in fluid communication with the perforated hole(s) so as to allow a coating material to flow into and through the hollow body and out of the perforated hole(s) at a location of at least a portion of one of the ceramic fibers. As such, the coating material is configured to cause the portion of one of the ceramic fibers to separate from the frame such that the portion is uniformly coated with the coating material.

METHOD FOR COATING FIBERS IN A FLUIDIZED BED

A method for coating fibers, includes desizing sized short fibers having an average length less than or equal to 5 mm, the short fibers being made of ceramic material or carbon, sieving the desized short fibers in order to separate them from any agglomerates of sized short fibers still present, introducing the desized and sieved short fibers into a reactor, and coating the short fibers in the reactor by chemical vapor deposition in a fluidized bed.

CONTROLLED PARTICLE INJECTION IN FABRIC FOR IMPROVED MICROSTRUCTRE HOMOGENEITY IN CMCs

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.

Additively manufactured composite components

An example technique includes extruding, by a tow deposition device, on a tow-by-tow basis, respective impregnated tows of a plurality of respective impregnated tows to form a layer of material on a major surface of a substrate. Each respective impregnated tow includes at least one ceramic fiber and a curable resin coating the at least one ceramic fiber. The example technique includes curing the curable resin to form a cured composite component. An example system includes a tow deposition device, an energy source, and a computing device. The computing device is configured to control the tow deposition device to extrude, on a tow-by-tow basis, respective impregnated tows of a plurality of respective impregnated tows to form a layer of material, and is configured to control the energy source to cure the curable resin to form a cured composite component.

Airfoil with fiber plies having interdigitated fingers in trailing end

An airfoil includes an airfoil section defining suction and pressure sides and leading and a trailing ends, the airfoil section being formed of a fiber-reinforced composite comprised of fiber plies, the fiber plies including at least one core fiber ply defining a tube that circumscribes an internal cavity and an overwrap fiber ply that wraps around the at least one core fiber ply, and aft of the internal cavity the overwrap fiber ply on the pressure side including first fingers and the overwrap ply on the suction side including second fingers, the first fingers being interdigitated with the second fingers to form an interlocked joint in the trailing end.

Method of fabricating a ceramic composite

A method of making a ceramic composite component includes providing a fibrous preform or a plurality of fibers, providing a first plurality of particles, coating the first plurality of particles with a coating to produce a first plurality of coated particles, delivering the first plurality of coated particles to the fibrous preform or to an outer surface of the plurality of fibers, and converting the first plurality of coated particles into refractory compounds. The first plurality of particles or the coating comprises a refractory metal.

ELECTROSTATIC FILAMENT DISPERSAL FOR CMC APPLICATIONS

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.

HOMOGENEOUS COMPOSITE MICROSTRUCTURE
20230019485 · 2023-01-19 ·

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. Each of the plurality of warp subtows and/or weft subtows is spaced apart from the closest adjacent warp subtow and/or weft subtow, respectively, a distance of 25 to 230 microns.