A method of making a ceramic matrix composite that exhibits moisture and environmental resistance has been developed. The method includes depositing a diffusion barrier layer comprising boron nitride on silicon carbide fibers and depositing a moisture-tolerant layer comprising silicon-doped boron nitride on the diffusion barrier layer, where a thickness of the moisture-tolerant layer is from about 3 to about 300 times a thickness of the diffusion barrier layer. Thus, a compliant multilayer including the moisture-tolerant layer and the diffusion barrier layer is formed. A wetting layer comprising silicon carbide, boron carbide, and/or pyrolytic carbon is deposited on the compliant multilayer layer. After depositing the wetting layer, a fiber preform comprising the silicon carbide fibers is infiltrated with a slurry. After slurry infiltration, the fiber preform is infiltrated with a melt comprising silicon and then the melt is cooled, thereby forming a ceramic matrix composite.

Thermoelectric (TE) nanocomposite material that includes at least one component consisting of nanocrystals. A TE nanocomposite material in accordance with the present invention can include, but is not limited to, multiple nanocrystalline structures, nanocrystal networks or partial networks, or multi-component materials, with some components forming connected interpenetrating networks including nanocrystalline networks. The TE nanocomposite material can be in the form of a bulk solid having semiconductor nanocrystallites that form an electrically conductive network within the material. In other embodiments, the TE nanocomposite material can be a nanocomposite thermoelectric material having one network of p-type or n-type semiconductor domains and a low thermal conductivity semiconductor or dielectric network or domains separating the p-type or n-type domains that provides efficient phonon scattering to reduce thermal conductivity while maintaining the electrical properties of the p-type or n-type semiconductor.

A method for manufacturing a part made of composite material includes injecting into a fibrous texture a slurry including at least one powder of refractory ceramic particles suspended in a liquid phase, filtering the liquid phase of the slurry and retaining the powder of refractory ceramic particles inside the texture so as to obtain a fibrous preform loaded with refractory ceramic particles, densifying the fibrous texture by treatment of the refractory ceramic particles present in the fibrous texture in order to form a refractory matrix in the texture. The method further includes, before injecting the slurry under pressure, pre-saturating the fibrous texture with a carrier fluid consisting in injecting into said texture a carrier fluid.

Provided are a composite material that has lower volume resistivity in comparison with SiC, SiC—Si, and the like, which are materials for forming constituent elements of an EHC, has low temperature dependence of volume resistivity, and thus is able to form a constituent element of a high-performance EHC; an electrode film, an electrode terminal, and a honeycomb substrate that are constituent elements of an EHC formed with such composite material, and a method for producing them. The composite material contains MoSi.sub.2 and at least one of Si or SiC, and is a material for forming a constituent element of an electrically heated catalytic converter. An electrode film 2, an electrode terminal 3, and a substrate 1 are produced from such composite material.

A refractory material contains: 40 mass % or more of MgO; 4 to 30 mass % of a free carbon component; and one or more of B.sub.2O.sub.3, P.sub.2O.sub.5, SiO.sub.2 and TiO.sub.2, in a total amount of 0.3 to 3 mass %, with the remainder being at least one other type of additional refractory component. A void layer exists in an interface between a carbon-containing matrix microstructure residing at least on opposite sides of a maximum-size one of a plurality of MgO-containing particles in the refractory material, and the maximum-size MgO-containing particle. A sum of respective thicknesses of the void layer at two positions on the opposite sides is 0.2 to 3.0% of a ratio with respect to particle size of the maximum-size MgO-containing particle. An inorganic compound of MgO and the one or more of B.sub.2O.sub.3, P.sub.2O.sub.5, SiO.sub.2 and TiO.sub.2 exists entirety or partially in a surface of each of the MgO-containing particles.

(Problem) In conventional method for producing artificial graphite, in order to obtain a product having excellent crystallinity, it was necessary to mold a filler and a binder and then repeat impregnation, carbonization and graphitization, and since carbonization and graphitization proceeded by a solid phase reaction, a period of time of as long as 2 to 3 months was required for the production and cost was high and further, a large size structure in the shape of column and cylinder could not be produced. In addition, nanocarbon materials such as carbon nanotube, carbon nanofiber and carbon nanohorn could not be produced. (Means to solve) A properly pre-baked filler is sealed in a graphite vessel and is subsequently subjected to hot isostatic pressing (HIP) treatment, thereby allowing gases such as hydrocarbon and hydrogen to be generated from the filler and precipitating vapor-phase-grown graphite around and inside the filler using the generated gases as a source material, and thereby, an integrated structure of carbide of the filler and the vapor-phase-grown graphite is produced. In addition, nanocarbon materials are produced selectively and efficiently by adding a catalyst or adjusting the HIP treating temperature.

A technique of forming a carbon-carbon composite that includes infiltrating a preform comprising carbon fibers or carbon-precursor fibers with a pitch and pyrolyzing the pitch using a controlled pressure and temperature ramp rate to control a growth of optical textures as the pitch is pyrolyzed to a coke matrix. Pyrolyzing the pitch may include initiating pyrolysis of at least some of the pitch at a first pressure less than about 2000 psi and a first temperature ramp rate between about 5 ° C./hr and about 50 ° C./hr to a first target temperature, and pyrolyzing at least some of the pitch at a second pressure greater than 2000 psi and a second temperature ramp rate between about 5 ° C./hr and about 50 ° C./hr to a second target temperature, where the second target temperature is greater than the first target temperature.

A powdery composition based on silica for ceramic welding, in particular by projection, comprising from 10 to 90% of a phase of siliceous particles comprise at least 80% by weight of cristobalite and at most 15% by weight of tridymite, based on the total weight of the composition, from 90 to 10% by weight of conventional additives forming a binding phase, based on the total weight of the composition, said siliceous particles having a d.sub.50 comprised between 350 and 800 μm, preferably between 400 and 500 μm.

The invention relates to a refractory product, a batch for producing the product, a method for producing the product, and a use of the refractory product.

A heat conduction member includes: a cylindrical ceramic body, a metal pipe on the outer periphery side of the cylindrical ceramic body, and an intermediate member held between the cylindrical ceramic body and the metal pipe. The cylindrical ceramic body has passages passing through from one end face to the other end face and allowing the first fluid to flow therethrough. The intermediate member is made of material having at least a part having a Young's modulus of 150 Gpa or less. The first fluid is allowed to flow through the inside of the cylindrical ceramic body while the second fluid having lower temperature than that of the first fluid is allowed to flow on the outer peripheral face side of the metal pipe to perform heat exchange between the first fluid and the second fluid.