Abstract: Methods of producing silicon carbide, and other metal carbide materials. The method comprises reacting a carbon material (e.g., fibers, or nanoparticles, such as powder, platelet, foam, nanofiber, nanorod, nanotube, whisker, graphene (e.g., graphite), fullerene, or hydrocarbon) and a metal or metal oxide source material (e.g., in gaseous form) in a reaction chamber at an elevated temperature ranging up to approximately 2400° C. or more, depending on the particular metal or metal oxide, and the desired metal carbide being produced. A partial pressure of oxygen in the reaction chamber is maintained at less than approximately 1.01×102 Pascal, and overall pressure is maintained at approximately 1 atm.

Abstract: Ceramic composite materials that are reinforced with carbide fibers can exhibit ultra-high temperature resistance. For example, such materials may exhibit very low creep at temperatures of up to 2700° F. (1480° C.). The present composites are specifically engineered to exhibit matched thermodynamically stable crystalline phases between the materials included within the composite. In other words, the reinforcing fibers, a debonding interface layer disposed over the reinforcing fibers, and the matrix material of the composite may all be of the same crystalline structural phase (all hexagonal), for increased compatibility and improved properties. Such composite materials may be used in numerous applications.

Abstract: Methods of producing continuous (or discontinuous) boron carbide fibers. The method comprises reacting a continuous or discontinuous carbon fiber material and a boron oxide gas within a temperature range of from approximately 1400° C. to approximately 2200° C. Articles including such partially or fully converted fibers may be provided, including such reinforcing fibers in a matrix of ceramic (a CMC), in metal (a MMC), or other matrix (e.g., polymer, etc.).

Abstract: A method of producing, from a continuous or discontinuous (e.g., chopped) carbon fiber, partially to fully converted metal carbide fibers. The method comprises reacting a carbon fiber material with at least one of a metal or metal oxide source material at a temperature greater than a melting temperature of the metal or metal oxide source material (e.g., where practical, at a temperature greater than the vaporization temperature of the metal or metal oxide source material). Additional methods, various forms of carbon fiber, metal carbide fibers, and articles including the metal carbide fibers are also disclosed.

Abstract: A multi-layered cladding material including a ceramic matrix composite and a metallic material, and a tube formed from the cladding material. The metallic material forms an inner liner of the tube and enables hermetic sealing of thereof. The metallic material at ends of the tube may be exposed and have an increased thickness enabling end cap welding. The metallic material may, optionally, be formed to infiltrate voids in the ceramic matrix composite, the ceramic matrix composite encapsulated by the metallic material. The ceramic matrix composite includes a fiber reinforcement and provides increased mechanical strength, stiffness, thermal shock resistance and high temperature load capacity to the metallic material of the inner liner. The tube may be used as a containment vessel for nuclear fuel used in a nuclear power plant or other reactor. Methods for forming the tube comprising the ceramic matrix composite and the metallic material are also disclosed.

Abstract: Methods of producing silicon carbide fibers. The method comprises reacting a continuous carbon fiber material and a silicon-containing gas in a reaction chamber at a temperature ranging from approximately 1500° C. to approximately 2000° C. A partial pressure of oxygen in the reaction chamber is maintained at less than approximately 1.01×102 Pascal to produce continuous alpha silicon carbide fibers. Continuous alpha silicon carbide fibers and articles formed from the continuous alpha silicon carbide fibers are also disclosed.

Abstract: Methods of producing continuous boron carbide fibers. The method comprises reacting a continuous carbon fiber material and a boron oxide gas within a temperature range of from approximately 1400° C. to approximately 2200° C. Continuous boron carbide fibers, continuous fibers comprising boron carbide, and articles including at least a boron carbide coating are also disclosed.

Abstract: Methods of producing silicon carbide fibers. The method comprises reacting a continuous carbon fiber material and a silicon-containing gas in a reaction chamber at a temperature ranging from approximately 1500° C. to approximately 2000° C. A partial pressure of oxygen in the reaction chamber is maintained at less than approximately 1.01×102 Pascal to produce continuous alpha silicon carbide fibers. Continuous alpha silicon carbide fibers and articles formed from the continuous alpha silicon carbide fibers are also disclosed.