Dry prepregs for ceramic matrix composites are described. The dry prepregs comprise a tow or fabric of ceramic fibers infiltrated with preceramic matrix comprising low levels of an aqueous solvent. The preceramic matrix contains an inorganic portion and a binder system. Binder systems comprising a binder and a plasticizer for the binder are described.

A lattice structure includes multiple identical unit cells formed from joined plates. In the lattice structure, some of the plates are rectangular plates, some of the plates are triangular plates, and some of the plates are trapezoidal plates. Further, any two of the joined rectangular plates have corresponding surface normals perpendicular to each other and at least two edges of each one of the triangular plates are joined to one of a surface or an edge of one of the plurality of joined plates. Further, at least three edges of each one of the trapezoidal plates are joined to one of a surface or an edge of one of the plurality of joined plates, and any one of a plurality of surface normals for the triangular plates and the trapezoidal plates are nonparallel to any one of a plurality of surface normals of rectangular plates.

The present disclosure relates to a method of fabricating a ceramic composite components. The method may include providing at least a first layer of reinforcing fiber material which may be a pre-impregnated fiber. An additively manufactured component may be provided on or near the first layer. A second layer of reinforcing fiber, which may be a pre-impregnated fiber may be formed on top the additively manufactured component. A precursor is densified to consolidates at least the first and second layer into a densified composite, wherein the additively manufactured material defines at least one cooling passage in the densified composite component.

A seal system includes a ceramic component, a metallic component, a coating system. The ceramic component has a first surface region that defines a first surface roughness. The metallic component is situated adjacent to the first surface region and has a second surface region facing the first surface region. The coating system includes a silicon-containing layer on the surface region of the ceramic component and barrier layer on the silicon-containing layer. The silicon containing layer has a surface in contact with the barrier layer and the barrier layer has a surface in contact with the metallic component. The surface of the barrier layer has a second surface roughness that is less than the first surface roughness. The barrier layer serves to limit interaction between silicon of the silicon-containing layer and elements of the metallic component. The barrier layer includes at least one of mullite, zircon, or hafnon.

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.

Ceramic matrix composite articles include, for example a first plurality of plies of ceramic fibers in a ceramic matrix defining a first extent, and a local at least one second ply in said ceramic matrix defining a second extent on and/or in said first plurality of plies with the second extent being less than said first extent. The first plurality of plies has a first property, the at least one second ply has at least one second property, and said first property being different from said at least one second property. The different properties may include one or more different mechanical (stress/strain) properties, one or more different thermal conductivity properties, one or more different electrical conductivity properties, one or more different other properties, and combinations thereof.

Flow path assemblies and methods for forming such flow path assemblies for gas turbine engines are provided. For example, a flow path assembly for a gas turbine engine has a boundary structure, an airfoil, and a locking feature. The boundary structure and the airfoil are formed from a composite material. The boundary structure defines an opening and a cutout proximate the opening, and the airfoil is sized to fit within the opening of the boundary structure. The locking feature is received within the cutout defined by the boundary structure to interlock the airfoil with the boundary structure.

Slurry and tape compositions include particles of a precursor that converts to a ceramic material when heated to a firing temperature, at least one binder that is capable of adhering the particles of the ceramic precursor together to form a pliable prepreg tape, at least one liquid plasticizer, and at least one solvent in which the binder is dissolved. The solvent may be sufficiently volatile to evaporate from the slurry composition during formation of the tape, yet the tape may also be pliable as a result of the slurry composition containing a sufficient amount of the liquid plasticizer.

A method of forming an integral fastener for a ceramic matrix composite component comprises the steps of forming a fiber preform with an opening, forming a fiber fastener, inserting the fiber fastener into the opening, and infiltrating a matrix material into the fiber preform and fiber fastener to form a ceramic matrix composite component with an integral fastener. A gas turbine engine is also disclosed.

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.