A hollow CMC article, a mandrel for forming the article and a method for forming the article are disclosed. The article includes a ply-wrap layer defining a cavity. The ply-wrap layer includes a first face, a second face, a root portion bridging the faces, and a plurality of CMC wrap plies. The root portion defines a terminus of the ply-wrap layer including a cross-sectional conformation consisting of a curve having a single turning point. Each of the plurality of CMC wrap plies are disposed along the first face, wrap over the root portion, and extend along the second face. The hollow article further includes a plurality of CMC lateral plies disposed along the faces.

A method of making a fiber preform for ceramic matrix composite (CMC) fabrication comprises laminating an arrangement of fibers between polymer sheets comprising an organic polymer, which may function as a fugitive binder during fabrication, to form a flexible prepreg sheet. A plurality of the flexible prepreg sheets are laid up in a predetermined geometry to form a stack, and the stack is heated to soften the organic polymer and bond together the flexible prepreg sheets into a bonded prepreg structure. Upon cooling of the bonded prepreg structure, a rigid preform is formed. The rigid preform is heated at a sufficient temperature to pyrolyze the organic polymer. Thus, a porous preform that may undergo further processing into a CMC is formed.

This invention relates generally to an article that includes a base substrate, an intermediate layer including at least one element or compound selected from titanium, chromium, indium, zirconium, tungsten, and titanium nitride on the base substrate, and a hydrophobic coating on the base substrate, wherein the hydrophobic coating includes a rare earth element material (e.g., a rare earth oxide, a rare earth carbide, a rare earth nitride, a rare earth fluoride, and/or a rare earth boride). An exposed surface of the hydrophobic coating has a dynamic contact angle with water of at least about 90 degrees. A method of manufacturing the article includes providing the base substrate and forming an intermediate layer coating on the base substrate (e.g., through sintering or sputtering) and then forming a hydrophobic coating on the intermediate layer (e.g., through sintering or sputtering).

Composite components that include features that provide improved wear characteristics at the interface between the composite component and a second component are provided. As one example, a composite component can include an integrally formed discontinuous molded tape (DMT) that defines a wear interface between the component and a second component. The wear interface defined by the DMT may provide improved durability of the composite component and may facilitate more uniform wear at the interface, among other benefits. Methods for manufacturing composite components having discontinuous molded tape wear interfaces are also provided.

Systems and methods for manufacturing unidirectional fiber prepreg tapes for CMC articles are provided. In one exemplary aspect, the method includes casting a matrix material on a carrier film to form a matrix film. The matrix material of the matrix film is then allowed to dry for a predetermined time. The matrix film is then wrapped on a drum and the matrix material is wet to a predetermined viscosity with a solvent. Thereafter, a fiber tow that includes of a plurality of fibers is wound about the drum so that the fiber tow penetrates into the matrix material and the matrix material impregnates the fiber tow to form the prepreg tape.

A method of making a ceramic matrix composite (CMC) article by combining a preceramic polymer with one or more sized nanopowders and optional surfactants and/or solvents to form a mixture suitable for 3D printing, depositing the mixture on a mandrel, curing it to form a green body, and pyrolyzing the green body such that the nanocrystalline surface of the CMC article has sufficiently the same surface roughness and figure accuracy of the mandrel to enable the CMC article to be used without further polishing. The mixture can be a paste or slurry that is self supporting and exhibit pseudoplastic rheology. The preceramic polymer is preferably a precursor to SiC, and the nanopowders preferably comprise SiC. The article can be densified by using polymer infiltration pyrolysis, with or without nanoparticles. The curing and pyrolysis of the article can be performed with microwave radiation. An example structure is a gradient density lattice with a mirror surface for use in a cryogenically cooled infrared optical system such as an orbiting space telescope.

Provided is a method including obtaining ceramic matrix composite (CMC) with a first matrix portion including a silicon carbide and silicon phase dispersed therewithin, disposing a coating thereupon to form a sealed part, and forming thereupon another segment comprising a CMC, which may be another matrix portion including a silicon carbide and a silicon phase dispersed within therewithin. Also provided is a gas turbine component with a CMC segment including a matrix portion including a silicon carbide and a silicon phase dispersed therewithin, a sealing layer including silicon carbide enclosing the first segment, and a second segment on the sealing layer, wherein the second segment includes a melt-infiltrated CMC having a matrix portion including a silicon carbide and a silicon phase dispersed therewithin.

A shaped material, for example, a disc for disc brakes, and a method for the manufacturing thereof. The shaped material has a plurality of layers of carbon fibers stacked along an overlap axis, each layer being formed by a plurality of radial segments and transverse segments. Each radial segment is adjacent and joined, on both sides, to a transverse segment and each transverse segment is adjacent and joined, on both sides, to a radial segment, forming in each layer an alternation of radial segments and transverse segments.

A method for manufacturing hollow composite material turbomachine part, includes producing a fibrous blank in one piece by three-dimensional weaving of yarns, the blank including at least one de-bonded zone forming an internal cavity, inserting a shaping part into the internal cavity of the fibrous blank in order to obtain a preform, densification of the preform by a matrix in order to obtain a structure having a fibrous reinforcement consisting of the preform densified by the matrix, wherein the shaping part is flexible and wherein the shaping part is mechanically withdrawn from the structure after the densification.

A gas turbine engine component includes a gas turbine engine component body formed of a ceramic matrix composite material having at least one fastener integrally formed with the gas turbine engine component body as a single-piece structure. The gas turbine engine component body initially comprises a rigidized preform structure formed from a polymer based material. The at least one fastener connects the gas turbine engine component body to an engine support structure.