A method is described for manufacturing a ceramic composite structure. The method includes wrapping ceramic fibers (22), such as SiC fibers, about the external surface of at least one form. The method further includes heating the wrapped fibers (22) to a temperature no greater than a first temperature, infiltrating voids (24) in the wrapped fibers (22) with the ceramic composite in a first vessel (12) at the first temperature, transferring the infiltrated wrapped fibers (22) from the first vessel (12) to a second vessel (14), distinct from the first vessel (12), and coating the infiltrated wrapped fibers (22) with the ceramic composite in the second vessel (14) at a second temperature, higher than the first temperature.

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.

A ceramic joined body includes a first aluminum oxide-based sintered body, a second aluminum oxide-based sintered body, an aluminum oxide-based joint layer located between the first aluminum oxide-based sintered body and the second aluminum oxide-based sintered body, and an aluminum oxide-based protrusion connected to the aluminum oxide-based joint layer, where the average diameter for closed pores of the aluminum oxide-based projection is 0.8 times or more and 1.5 times or less as large as the average diameter for closed pores for each of the first aluminum oxide-based sintered body and the second aluminum oxide-based sintered body.

A bonding method is capable of firmly bonding a greater variety of materials using an electrochemical reaction. The bonding method includes a placement step of placing an oxygen ion conductor and a conductive member that includes an oxide layer on a surface thereof in contact with each other via the oxide layer, a connection step of connecting the oxygen ion conductor to the positive electrode side of a voltage application device and connecting the conductive member to the negative electrode side of the voltage application device, and a voltage application step of applying voltage between the oxygen ion conductor and the conductive member to bond the oxygen ion conductor and the conductive member.

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.

A nuclear reactor fuel rod is a fuel rod for a light-water reactor. The nuclear reactor fuel rod includes a fuel cladding tube and an end plug, both of which are formed of a silicon carbide material. A bonding portion between the fuel cladding tube and the end plug is formed by brazing with a predetermined metal bonding material interposed, and/or by diffusion bonding. The predetermined metal bonding material has a solidus temperature of 1200 C. or higher. An outer surface of the bonding portion, and a portion of an outer surface of the fuel cladding tube and the end plug, which is adjacent to the outer surface of the bonding portion are covered by bonding-portion coating formed of a predetermined coating metal. The predetermined metal bonding material and the predetermined coating metal have an average linear expansion coefficient which is less than 10 ppm/K.

A semiconductor manufacturing device member according to the present invention includes a ceramic disc with an internal electrode and a ceramic shaft that supports the disc. The disc and the shaft are integrated without having a bonding interface.

Methods for repairing composite cylindrical components are provided. One exemplary method for repairing a cylindrical component defining an axial direction, a radial direction, and a circumferential direction includes removing a damaged region of the cylindrical component. A flange extending from a cylindrical body of the cylindrical component is included in the damaged region. One or more arc segments that extend along the circumferential direction are connected with the existing cylindrical component. At least one of the arc segments includes a prefabricated flange. One or more plies are laid up to connect the arc segments with the existing cylindrical component to repair the damaged region of the cylindrical body and the prefabricated flange formed integrally with one of the arc segments replaces the damaged portion of the flange. Repaired cylindrical components are also provided.

The invention relates to sealing a fuel rod composite cladding tube composed of silicon carbide regardless of the fuel rod cladding design architecture (e.g., monolithic, duplex with monolithic SiC on the inside and a composite made with SiC fibers and SiC matrix on the outside) preferably with sealed SiC end plug caps, additionally sealed with an interior braze and exterior SiC final coating, thus providing a double sealed end plug barrier effective at retaining gas tightness and providing mechanical strength for the sealed end joint while providing high chemical resistance.