Abstract: A brake element and system where the brake friction surface of the element is a refractory metal carbide. The brake element has a molded carbon structure for mechanical and structural strength and the friction surface or surfaces thereon are converted to refractory metal carbide. The refractory metal carbide is preferably silicon carbide and the depth of conversion is preferably from 0.015 inches to 0.15 inches.

Abstract: A thin film of substantially defect-free pyrolytic graphite, useful as a bi-directional reinforcing material, is formed by vapor deposition on an inert liquid substrate surface and separated therefrom. The substrate temperature is substantially below the melting point of the refractory material and the substrate surface is smooth and free of stress to enable formation of a substantially defect-free film. Thin films of other refractory materials can be made similarly by first forming a pyrolytic graphite film on the substrate, and then vapor depositing a film of refractory material on the pyrolytic graphite surface. The pyrolytic graphite and refractory material films are then separated from the substrate surface and then separated from each other. Various refractory film materials can be made including pyrolytic grahite; boron; silicon; and refractory carbides, borides and nitrides. For making pyrolytic graphite films, it is preferable to use tin as the ubstrate, at a temperature of about 1600-1800.degree. C.

Abstract: An elongated continuous porous sheet of fibrous carbon, such as paper of matted graphite fibers, woven graphite cloth or carbonized filter paper is longitudinally traversed through a reduced pressure heating zone (5mm. of Hg.) in which hydrocarbon gas is perpendicularly directed at relatively high velocities through restricted flow passages at the sheet, which is heated to a temperature of about 2200.degree. C. The flow passages are disposed in polycrystalline graphite guide plates forming a narrow slot through which the material passes. The gas flow cools the passages and prevents the hydrocarbon content from depositing out on and clogging them. The hydrocarbon gas impinges on the heated fibers and forms a deposit of pyrolytic carbon on them, which is heavier in back than in front. A pair of 13 mil. thick sheets are effectively infiltrated within a 40 mil. deep slot. The sheets are traversed at a speed of about 60 to 3600 feet per hour at a temperature of about 2000.degree. to 2400.degree.

Abstract: An elongated continuous porous sheet of fibrous carbon, such as paper of matted graphite fibers, woven graphite cloth or carbonized filter paper is longitudinally traversed through a reduced pressure heating zone (5 mm. of Hg.) in which hydrocarbon gas is perpendicularly directed at relatively high velocities through restricted flow passages at the sheet, which is heated to a temperature of about 2200.degree.C. The sheets are traversed at a speed of about 60 to 3600 feet per hour at a temperature of about 2000.degree. to 2400.degree.C at a pressure of from about 4 to 20 mm. Hg. A hydrocarbon gas, at a flow rate of from about 5 to 20 c.f.m. effectively infiltrates the carbon sheet material and increases the sheet density by at least 20 grams per square meter. The velocity of the carbon depositing flow stream is maintained at from about 20 to 200 ft. per minute (STP).