A method to produce a protective surface layer having a predetermined topography on a ceramic matrix composite is described. The method includes applying a slurry layer to a surface of a fiber preform, and drying the slurry layer to form a particulate layer. A surface of the particulate layer is machined to improve surface smoothness and to form a machined surface. A ceramic tape is attached to the machined surface, and a tool comprising one or more features to be imprinted is placed on the ceramic tape, thereby forming a compression assembly. Heat and pressure are applied to the compression assembly to consolidate and bond the ceramic tape to the machined surface, while the one or more features of the tool are imprinted. Thus, a protective surface layer having a predetermined topography is formed.

A manufacturing method for a ceramic matrix composite, having a woven fabric that has multiple fiber bundles and having a matrix that is disposed in the gaps between the fiber bundles, includes: a green body formation step for forming a green body by sintering the woven fabric infiltrated with a polymer that is a precursor to the matrix; and a densification step for further infiltrating the green body with a polymer and sintering same. The densification step includes: a second infiltration step for further infiltrating the green body with a polymer so as to form an infiltrated green body; a drying step for drying the infiltrated green body so as to form a dried green body; a steam treatment step for leaving the dried green body under saturation water vapor pressure so as to form a treated green body; and a sintering step for sintering the treated green body.

A metal-on-ceramic substrate comprises a ceramic layer, a first metal layer, and a bonding layer joining the ceramic layer to the first metal layer. The bonding layer includes thermoplastic polyimide adhesive that contains thermally conductive particles. This permits the substrate to withstand most common die attach operations, reduces residual stress in the substrate, and simplifies manufacturing processes.

Methods of forming ceramic matrix composite structures include joining at least two lamina together to form a flexible ceramic matrix composite structure. Ceramic matrix composite structures include at least one region of reduced inter-laminar bonding at a selected location between lamina thereof. Thermal protection systems include at least one seal comprising a ceramic matrix composite material and have at least one region of reduced inter-laminar bonding at a selected location between lamina used to form the seal. Methods of forming thermal protection systems include providing one or more such seals between adjacent panels of a thermal protection system.

Cutting elements include a diamond-bonded body attached with a substrate. The substrate has a coercivity of greater than about 200 Oe, and has a magnetic saturation of from about 73 to 90. The diamond-bonded body has a compressive stress at the surface of greater than about 0.9 GPa after heat treatment, and greater than about 1.2 GPa prior to heat treatment.

Methods for forming a unitary ceramic component are provided. The method may include: positioning a braze reactant layer in a contact area between a first densified ceramic component and a second densified ceramic component; positioning a pack material around at least a portion of the first densified ceramic component or the second densified ceramic component; positioning at least one infiltrate source in fluid communication with the braze reactant layer; and thereafter, heating the at least one infiltrate source, the pack material, the first densified ceramic component, and the second densified ceramic component to a braze temperature that is at or above a melting point of at least one phase of the infiltrate composition such that at least one phase of infiltrate composition melts and flows into the braze reactant layer and reacts with a ceramic precursor compound therein to form a ceramic material.

A method to produce a protective surface layer having a predetermined topography on a ceramic matrix composite is described. The method includes applying a slurry layer to a surface of a fiber preform, and drying the slurry layer to form a particulate layer. A surface of the particulate layer is machined to improve surface smoothness and to form a machined surface. A ceramic tape is attached to the machined surface, and a tool comprising one or more features to be imprinted is placed on the ceramic tape, thereby forming a compression assembly. Heat and pressure are applied to the compression assembly to consolidate and bond the ceramic tape to the machined surface, while the one or more features of the tool are imprinted. Thus, a protective surface layer having a predetermined topography is formed.

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 invention relates to a composite material based on boron nitride (BN(C)) in the form of a continuous structure; and a phase change material (PCM) incorporated within said continuous BN(C) structure and is embedded within a polymer layer, a process for manufacturing same, and the components that comprise same.

The present invention discloses a polyimide-based composite carbon film with high thermal conductivity and a preparation method therefor. The preparation method includes: uniformly coating the surface of a polyimide-based carbon film with an aqueous graphene oxide solution, and then covering the same with another polyimide-based carbon film uniformly coated with an aqueous graphene oxide solution; repeating such operation; after the polyimide-based carbon films are dried, bonding the polyimide-based carbon films by means of graphene oxide so as to form a thick film; bonding the polyimide-based carbon films more tightly by means of further low-temperature hot pressing; and finally, obtaining a thick polyimide-based carbon film with high thermal conductivity by repairing defects by means of low-temperature heating pre-reduction and high-temperature and high-pressure thermal treatment. The thick polyimide-based carbon film with high thermal conductivity has a thickness greater than 100 m and an in-plane thermal conductivity of even reaching 1700 W/mK or above.