Abstract: A method of making shaped bodies of silicon carbide, of graphite coated with silicon carbide or of a graphite-like material with a silicon carbide surface wherein a graphitic body is assembled from preformed parts in the desired shape and is immersed, under a chemically inert atmosphere, in a silicon melt and after penetration of the melt into gaps between abutting surfaces of the body and after reaction of the silicon with the graphite or the graphite-like material to form silicon carbide at the junctions, the body is removed from the melt and is cooled in a chemically inert atmosphere.

Abstract: In order to provide enough permeability (air or liquid throughput) in a pus molded body of carbon made from a mixture of carbon powder and a binder, a first "green" body (a body of the kind that has been fired heretofore, in its green state before firing) is broken up into small pieces with the help of a jaw crusher in a manner providing coarse particles and a fraction of uniform size (largest particle diameter not more than twice the smallest) in the overall range between 0.2 and 10 mm effective diameter is used to make a second green body of molded shape by placing it in a die and applying a pressure which may be light or heavier according to the desired degree of permeability. The second green body is then coked in vacuum or in an inert atmosphere at a temperature in the range between 600.degree. to 1000.degree. C. to produce a strong body through which gas and liquid may pass with a facility far exceeding what has been accomplished before with a body of comparable strength.

Abstract: A porous green-state body of carbon, with or without silicon carbide, made with a cokable binder, is crumbled to produce relatively coarse grains in the range from 0.2 to 10 mm and a fraction of the particles so produced with a much more limited range of grain size is then used to produce a second green-state body, which is then coked, siliconized if the silicon is not already provided in the making of the precursor body that was broken up, and converted into a silicon carbide body. If the siliconizing is done by immersion in a bath of molten silicon, the excess silicon is removed by vaporization or by boiling in sodium hydroxide solution.

Abstract: In the production of shaped silicon-carbide bodies, especially tubes which onsist predominantly of silicon carbide throughout their thickness for use in nuclear-reactor technology, a carbon-containing preform (body of the desired shape) is contacted with elemental silicon powder at a temperature of 1400.degree. C. to 1500.degree. C. and the silicon-contacted carbon-containing body is thereafter treated at a temperature of 1800.degree. C. to 2000.degree. C. to transform at least the major part of the carbon into silicon carbide.