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.

The present disclosure relates to abrasive articles including an abrasive member having opposing major surfaces, a working surface and an exterior attachment surface, wherein the abrasive member comprises an inorganic material having a Mohs hardness greater than about 7.0; and a magnetic member, having opposing first and second major surfaces and a corresponding magnetic force, wherein the first major surface of the magnetic member faces the exterior attachment surface. The abrasive articles of the present disclosure may include a third member. The third member is attached to the magnetic member by a magnetic force. The abrasive member with attached magnetic member is designed to be easily removed from the third member. Methods of separating an abrasive member from an abrasive article and replacing the abrasive member of an abrasive article are also provided.

An aerospace mirror having a reaction bonded (RB) silicon carbide (SiC) mirror substrate, and a SiC cladding on the RB SiC mirror substrate forming an optical surface on a front side of the aerospace mirror. A method for manufacturing an aerospace mirror comprising obtaining a green mirror preform comprising porous carbon, silicon carbide (SiC), or both, the green mirror preform defining a front side of the aerospace mirror and a back side of the aerospace mirror opposite the front side; removing material from the green mirror preform to form support ribs on the back side; infiltrating the green mirror preform with silicon to create a reaction bonded (RB) SiC mirror substrate from the green mirror preform; forming a mounting interface surface on the back side of the aerospace mirror from the RB SiC mirror substrate, and forming a reflector surface of the RB SiC mirror substrate on the front side of the aerospace mirror. Additionally, the method can comprise cladding the reflector surface of the RB SiC mirror substrate with SiC to form an optical surface of the aerospace mirror.

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.

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.

Systems, devices, and methods are provided for manufacturing a carbon ceramic brake disc. Generally, a plurality of uncured or partially-cured bulk molding compound preforms or molding compound layers and ventilation cores are placed in a mold cavity and warm-pressed at a first temperature. The ventilation cores are removed from the resulting cured green body. The cured green body is then removed from the mold, and treated through a polymer infiltration and pyrolysis or reactive melt infiltration process. Certain steps can be repeated until a desired target density or weight is attained.

Systems, devices, and methods are provided for manufacturing a carbon ceramic brake disc. Generally, a plurality of uncured or partially-cured bulk molding compound preforms or molding compound layers and ventilation cores are placed in a mold cavity and warm-pressed at a first temperature. The ventilation cores are removed from the resulting cured green body. The cured green body is then removed from the mold, and treated through a polymer infiltration and pyrolysis or reactive melt infiltration process. Certain steps can be repeated until a desired target density or weight is attained.

A method to produce a ceramic matrix composite with controlled surface characteristics includes: applying a scrim ply to a surface of a fiber preform, where the fiber preform includes silicon carbide fibers coated with boron nitride; infiltrating the fiber preform and the scrim ply with a slurry, thereby forming an impregnated ply on an impregnated fiber preform; infiltrating the impregnated fiber preform and the impregnated ply with a melt comprising silicon, and then cooling, thereby forming a ceramic matrix composite having a ceramic surface layer thereon, where the ceramic surface layer has a predetermined thickness and is devoid of boron; machining or grit blasting the ceramic surface layer to form an intermediate layer suitable for coating; and depositing an environmental barrier coating on the intermediate layer. Thus, a ceramic matrix composite coated with the environmental barrier coating is formed with the intermediate layer in between.

In some examples, article used as a component for a turbine engine that operates in a high temperature environment. The article may include: a ceramic or ceramic matrix composite (CMC) substrate; and a coating on the ceramic or the CMC substrate, wherein the coating defines an outer surface of the article. The coating includes a plurality of surface features defining channels on the outer surface of the article. The channels are configured to modify a flow of molten Calcia-Magnesia-Alumina Silicate (CMAS) over the outer surface of the coating in a gas flow over the outer surface of the article to reduce accumulation of the molten CMAS on the outer surface of the article.

In some examples, article used as a component for a turbine engine that operates in a high temperature environment. The article may include: a ceramic or ceramic matrix composite (CMC) substrate; and a coating on the ceramic or the CMC substrate, wherein the coating defines an outer surface of the article. The coating includes a plurality of surface features defining channels on the outer surface of the article. The channels are configured to modify a flow of molten Calcia-Magnesia-Alumina Silicate (CMAS) over the outer surface of the coating in a gas flow over the outer surface of the article to reduce accumulation of the molten CMAS on the outer surface of the article.