Abstract: A spring member made of a carbon fibers/carbon composite material in which carbon fibers are dispersed in a matrix of graphite, The spring member has a spring constant in a range of 0.1 to 25 kg/mm and a density of about 1.5 to 3.0 g/cm.sup.3. For use in high temperature severe conditions a ceramic material is incorporated into the surface of the spring member.

Abstract: A three-layer heat-resistant material is disclosed which includes a substrate of a carbon fiber-reinforced carbon composite, an outer metal layer and a ceramic layer interposed between the substrate and the metal layer. A conveyer belt using the heat-resistant material is also disclosed.

Abstract: A spring member made of a carbon fibers/carbon composite material in which carbon fibers are dispersed in a matrix of graphite, and a process for producing such a spring member. The process includes the steps of: (a) forming raw preformed yarns; (b) shaping the raw preformed yarns in a form of a yarn member, a taper member or a sheet member; (c) coiling the thus shaped member around a core rod together with a coiling spacer; (d) molding the coiled member by hot pressing at about 300.degree. C.-2000.degree. C. under a given pressurized pressure; and graphitizing the coiled member at 1500.degree. C.-3000.degree. C., after carbonizing at 700.degree.-1200.degree.C. if necessary.

Abstract: A preformed yarn useful for forming composite articles is disclosed which includes a core of a multiplicity of fibers, fine powder provided in the interstices between the fibers, and a flexible sleeve formed of a thermoplastic resin and surrounding the core. The fine powder is formed of a material which neither melts nor reacts with the thermoplastic resin at a temperature up to 450.degree. C. and at a temperature up to the melting point of the thermoplastic resin. The incorporation of the fine powder between the fibers is effected by injecting fine powder-containing air from a jet nozzle and blowing the air against a bundle of the fibers.

Abstract: A continuous process for the production of carbonaceous pitch, including heat-treating an aromatic heavy oil in a first thermal cracking zone for obtaining a first cracked product, and introducing the first cracked product into a second thermal cracking zone where it is thermally cracked by direct contact with a gaseous heat transfer medium to form distillable cracked components and a mesophase-containing pitch. The liquid phase in the second thermal cracking zone, including the mesophase-containing pitch, is discharged therefrom and separated into a mesophase-rich pitch and a matrix pitch having a low concentration of mesophase. The mesophase-rich pitch is recovered while at least a portion of the matrix pitch is recycled to the second thermal cracking zone.