A method for producing an acoustic attenuation panel from a composite material with a ceramic oxide matrix is provided that includes draping a plurality of plies having fibrous reinforcements including fibers of ceramic material in a mold to define a first skin, depositing blocks made of fugitive material on the first skin such that a space between two blocks is defined, and draping a second plurality of plies on a surface formed by the blocks such that a second skin is defined. Rounded corners of the blocks define radii for connecting the first and second skins with walls of a honeycomb core of the acoustic panel. The method further includes using a liquid medium to infiltrate the skins and spaces with a precursor of a ceramic phase, removing the liquid medium by evaporation or polymerization, and sintering to consolidate the ceramic oxide material and removal the fugitive material.

A method of producing a ceramic matrix composite including a protective ceramic coating thereon comprises applying a surface slurry onto an outer surface of an impregnated fiber preform. The surface slurry includes particulate ceramic solids dispersed in a flowable preceramic polymer comprising silicon, and the impregnated fiber preform comprises a framework of ceramic fibers loaded with particulate matter. The flowable preceramic polymer is cured, thereby forming on the outer surface a composite layer comprising a cured preceramic polymer with the particulate ceramic solids dispersed therein. The cured preceramic polymer is then pyrolyzed to form a porous ceramic layer comprising silicon carbide, and the impregnated fiber preform and the porous ceramic layer are infiltrated with a molten material comprising silicon. After infiltration, the molten material is cooled to form a ceramic matrix composite body with a protective ceramic coating thereon.

A seal assembly for a gas turbine engine according to an example of the present disclosure includes a seal that has a main body extending circumferentially between opposed mate faces. The main body has a sealing portion and an engagement portion extending outwardly from sealing portion along at least one of the mate faces. The main body has a core that has one or more core plies having a first fiber construction and arranged to establish an internal cavity. An overwrap has one or more overwrap plies having a second fiber construction and arranged to follow a perimeter of the one or more core plies to establish the engagement portion and the sealing portion, and the second fiber construction differs from the first fiber construction. The first fiber construction establishes a first target fiber volume fraction, the second fiber construction establishes a second target fiber volume fraction. A method of fabricating a seal for a gas turbine engine is also disclosed.

A selective laser sintering system includes a leveling roller having a first orientation. The leveling roller is configured to roll over a first feed bin. The build chamber is configured to receive, from the first feed bin and by the leveling roller, a transfer of a portion of matrix material. The selective laser sintering system is configured to transfer the portion to the build chamber in a number of orientations.

A composite material part includes a fiber preform forming fiber reinforcement including a stack of at least two fiber plies, each of the fiber plies being made of an interlock weave three-dimensional fabric and each of the fiber plies having a number of warp yarn layers or a number of weft yarn layers that is greater than or equal to three; and a matrix present in the pores of the fiber preform.

Adhesive compositions and methods for bonding materials with different thermal expansion coefficients is provided. The adhesive is formulated using a flux material, a low flux material, and a filler material, where the filler material comprises particulate from at least one of the two components being bonded together. A thickening agent can also be used as part of the adhesive composition to aid in applying the adhesive and establishing a desired bond thickness. The method of forming a high strength bond using the disclosed adhesive does not require the use of intermediary layer or the use of high cure temperatures that could damage one or both of the components being bonded together.

A seed crystal holder for pulling up a single crystal is made of a carbon fiber-reinforced carbon composite material, and has a substantially cylindrical shape with a hollow space having a shape matching an outer shape of a substantially rod-shaped seed crystal. A direction of carbon fibers at a part in contact with at least an outer peripheral surface of the seed crystal has isotropy as viewed from a central axis of the hollow space.

The present invention relates to a gastight multilayer composite tube having a heat transfer coefficient of >500 W/m.sup.2/K and comprising at least two layers, namely a layer of nonporous monolithic oxide ceramic and a layer of oxidic fiber composite ceramic, a connecting piece comprising at least one metallic gas-conducting conduit which in the longitudinal direction of the composite tube overlaps in a region at least two ceramic layers, where the one ceramic layer comprises a nonporous monolithic ceramic and the other ceramic layer comprises a fiber composite ceramic, and also the use of the multilayer composite tube as reaction tube for endothermic reactions, radiation tubes, flame tubes or rotary tubes.

The present invention relates to a short carbon fiber-reinforced composite material, including a base material part and at least one sliding part contacting the base material part, in which each of the base material part and the sliding part has a plurality of short carbon fiber bundles in which at least a part thereof has been converted into SiC and a SiC matrix present among the plurality of short carbon fiber bundles, as constituent components, and the short carbon fiber bundles of the sliding part have a SiC conversion higher than that of the short carbon fiber bundles of the base material part.

A seed crystal holder for pulling up a single crystal is made of a carbon fiber-reinforced carbon composite material, and has a substantially cylindrical shape with a hollow space having a shape matching an outer shape of a substantially rod-shaped seed crystal. A direction of carbon fibers at a part in contact with at least an outer peripheral surface of the seed crystal has isotropy as viewed from a central axis of the hollow space.