Method of making a structure from carbonaceous fibers

A carbonizable body is formed by infusing a plurality of preoxidized, preferably stabilized by known processing to have about 17 to 30 weight percent oxygen, fibers prepared from pitch, in a non-polar liquid plasticizer, typically quinoline, capable of extracting a tarry leachate from the fibers. The infusion of the fibers in the plasticizer is continued for a sufficient time for a substantial amount of leachate to form on the surface of the fibers. The treated fibers are then consolidated or diffusion-bonded to one another or other fibers, as by orienting the treated fibers in a mold and subjecting them to isostatic pressing at relatively low temperatures and pressure. Further processing of the consolidated fibers with appropriate heat treatment in an inert atmosphere will produce a carbonized bulk product with higher values of Young's modulus for the carbonized material than have been previously achieved at such carbonization temperatures. This carbonaceous product can be truly graphitized by subsequent heat treatment to obtain material with a modulus of at least 40x106 psi, and a tensile strength of at least 20x103 psi.