Channel boxes for a boiling water reactor and methods of manufacture thereof are provided. The channel box comprises a substrate and a first layer. The substrate comprises a tubular shape. The substrate comprises silicon carbide fibers. The first layer is deposited on a first surface of the substrate and the first layer comprises a corrosion resistant metallic composition.

Thermally-conductive ceramic and ceramic composite components suitable for high temperature applications, systems having such components, and methods of manufacturing such components. The thermally-conductive components are formed by a displacive compensation of porosity (DCP) process and are suitable for use at operating temperatures above 600° C. without a significant reduction in thermal and mechanical properties.

Thermally-conductive ceramic and ceramic composite components suitable for high temperature applications, systems having such components, and methods of manufacturing such components. The thermally-conductive components are formed by a displacive compensation of porosity (DCP) process and are suitable for use at operating temperatures above 600° C. without a significant reduction in thermal and mechanical properties.

A fluid heating component including: a pillar-shaped member made of ceramics and formed with through channels through which a fluid passes, and a conductive coating layer disposed on at least a part of a circumferential surface of the pillar-shaped member, wherein the conductive coating layer is disposed on coats the whole circumference of a cut surface of the pillar-shaped member in a state where the conducive coating layer is electrically connected, in the cut surface of the pillar-shaped member which is perpendicular to a passing direction of the fluid.

A fluid heating component including: a pillar-shaped member made of ceramics and formed with through channels through which a fluid passes, and a conductive coating layer disposed on at least a part of a circumferential surface of the pillar-shaped member, wherein the conductive coating layer is disposed on coats the whole circumference of a cut surface of the pillar-shaped member in a state where the conducive coating layer is electrically connected, in the cut surface of the pillar-shaped member which is perpendicular to a passing direction of the fluid.

A ceramic substrate includes a substrate main body, and a conductor layer provided inside of the substrate main body. The substrate main body includes an insulator layer that is ceramics composed of aluminum oxide, and a composite oxide layer of aluminum and silicon, the composite oxide layer being formed between the insulator layer and the conductor layer.

A ceramic substrate includes a substrate main body, and a conductor layer provided inside of the substrate main body. The substrate main body includes an insulator layer that is ceramics composed of aluminum oxide, and a composite oxide layer of aluminum and silicon, the composite oxide layer being formed between the insulator layer and the conductor layer.

A method of forming a doped substrate comprises heating a substrate comprising a layer of a dopant on at least one surface to a predetermined temperature; applying a predetermined degree of isostatic external pressure on the surface of said substrate at said predetermined temperature for a time sufficient to induce thermal migration of the dopant into the substrate to provide a doped substrate; and removing the isostatic pressure and cooling the doped substrate to about room temperature. The substrate is a glass material, a single crystal material, a poly-crystalline material, a ceramic material, or a semiconductor material, and the substrate may be optically transparent. The dopant comprises one or more transition metals, one or more rare earth elements, or a combination of both. The layer of a dopant comprises one or more segregated layers of distinct chemical species. The isostatic pressure and elevated temperature may be applied simultaneously or sequentially.

A method of forming a doped substrate comprises heating a substrate comprising a layer of a dopant on at least one surface to a predetermined temperature; applying a predetermined degree of isostatic external pressure on the surface of said substrate at said predetermined temperature for a time sufficient to induce thermal migration of the dopant into the substrate to provide a doped substrate; and removing the isostatic pressure and cooling the doped substrate to about room temperature. The substrate is a glass material, a single crystal material, a poly-crystalline material, a ceramic material, or a semiconductor material, and the substrate may be optically transparent. The dopant comprises one or more transition metals, one or more rare earth elements, or a combination of both. The layer of a dopant comprises one or more segregated layers of distinct chemical species. The isostatic pressure and elevated temperature may be applied simultaneously or sequentially.

A method of protecting a carbon-containing composite material part against oxidation, includes applying a first coating composition in the form of an aqueous suspension on an outside surface of the part, the first coating composition including a metallic phosphate; a powder of an ingredient comprising titanium; and a powder of B.sub.4C; subjecting the applied first coating composition to heat treatment in order to obtain a first coating on the outside surface of the part; applying a second coating composition on the first coating composition, the second coating composition including an aqueous suspension of colloidal silica; a powder of borosilicate glass; and a powder of TiB.sub.2; and subjecting the applied second coating composition to second heat treatment in order to obtain a second coating on the first coating.