Abstract: A process has been developed for fabricating composite structures using either reaction forming or polymer infiltration and pyrolysis techniques to densify the composite matrix. The matrix and reinforcement materials of choice can include, but are not limited to, silicon carbide (SiC) and zirconium carbide (ZrC). The novel process can be used to fabricate complex, net-shape or near-net shape, high-quality ceramic composites with a crack-free matrix.

Abstract: Provided is a production process for a carbonized product characterized by comprising the following steps (a) to (b): (a) a step in which metal-made or ceramic-made plural granular matters are charged into a heat treating apparatus which is maintained at a temperature of 400° C. or higher and 700° C. or lower and allowed to move therein and in which a carbonized product precursor is fed into the above apparatus and subjected to heat treatment, whereby the carbonized product is adhered on the surface of the above granular matters and (b) a step in which the carbonized product adhered on the surface of the granular matters is heated at a higher temperature than the heat treating temperature in the step (a) and 900° C. or lower, whereby the carbonized product is separated from the granular matters. The present invention provides a production process for an inexpensive and useful carbonized product by simple apparatus and steps.

Abstract: The present invention discloses a method for fabricating a carbon membrane having pore regularity. The method comprises: providing a template having a plurality of pores arranged regularly; performing a tubular carbon forming process in the regularly-arranged pores; then performing a removal process to form an annular cavity; performing a carbon forming process in the annular cavity to combine the carbon in the annular cavity with the tubular carbon to thereby form a carbon substance having a thick wall; and repeatedly performing the removal process and the carbon forming process so as to form a carbon membrane having pore regularity.

Abstract: Low cost isotropic and/or mesophase pitch is used to densify carbon fiber preforms by VPI and/or RTM equipment in place of CVI/CVD processing, for reduced manufacturing cycle times and costs and reduced need for expensive densification equipment. The process includes: heat treating a carbon fiber preform; infiltrating the preform with a pitch feedstock by VPI and/or RTM; carbonizing the pitch-infiltrated carbon fiber preform at 1200-2450° C. with a hold time of 4 hrs to ensure the entire furnace reaches the max temperature; repetition of the pitch infiltration and carbonization steps until the density of the preform is about 1.7 g/cc or higher; and a final heat-treatment of the densified composite. Brake discs manufactured in this way have higher densities and better thermal characteristics, which result in improved mechanical properties and friction and wear performance as compared with conventional CVI/CVD-densified brake discs.

Abstract: Method for producing carbon-carbon composite brake discs by: (a) providing annular nonwoven carbon fiber brake disc preforms; (b) carbonizing the brake disc preforms; (c) densifying the carbonized preforms by CVD/CVI (chemical vapor deposition/chemical vapor infiltration); (d) densifying the products of step (c) with isotropic or mesophase pitch by VPI (vacuum pitch infiltration) or RTM (resin transfer molding) processing; (e) carbonizing the preforms to remove non-carbon volatiles from the pitch and to open porosity in the pitch-infused preforms; (f) densifying the products of step (e) with isotropic or mesophase pitch by VPI or RTM processing; (g) carbonizing the preforms to remove non-carbon volatiles from pitch and to open porosity in the pitch-infused preforms; and (h) heat-treating the resulting pitch-densified carbon-carbon composite brake disc preforms. This manufacturing approach reduces lot-to-lot variability in friction performance of the resulting carbon-carbon composite brake discs.

Abstract: A process for preparing graphite articles is presented. In particular, the process includes employing a particulate fraction comprising at least about 35 weight percent coke, coal or combinations thereof having a diameter such that a major fraction of it passes through a 0.25 mm to 25 mm mesh screen. The particulate fraction is mixed with a liquid or solid pitch binder, to form a stock blend; the stock blend is extruded to form a green stock; the green stock is baked to form a carbonized stock; and the carbonized stock is graphitized. The stock blend further includes carbon fibers added after mixing of the particulate fraction and pitch has begun.

Abstract: A lithographic apparatus including a filter device is disclosed. The filter device has a plurality of foils attached to a holder which is able to rotate around a rotation axis. The foils are arranged substantially parallel to the rotation axis. The foils comprise a uni-directional carbon-fiber composite material selected from the group consisting of carbon-carbon composite (C-C composite) and carbon-silicon carbide composite (C—SiC composite). During operation, the filter device rotates and filters out debris from a radiation source, such as a Sn plasma source. Such a filter device per se may be provided.

Abstract: A graphite electrode for an electrothermic reduction furnace is formed from anode grade coke and graphitized at a graphitization temperature below 2700° C. The resulting electrode is particularly suited for carbothermal reduction of alumina. It has an iron content of about 0.05% by weight, a specific electrical resistivity of above 5 ?Ohm·m, and a thermal conductivity of less than 150 W/m·K. The graphite electrode is manufactured by first mixing calcined anode coke with a coal-tar pitch binder, and a green electrode is formed from the mixture at a temperature close to the softening point of the pitch binder. The green electrode is then baked to carbonize the pitch binder to solid coke. The resultant carbonized electrode, after further optional processing is then graphitized at a temperature below 2700° C. for a time sufficient to cause the carbon atoms in the carbonized electrode to organize into the crystalline structure of graphite.

Abstract: A graphite material includes a plurality of graphite particles and a plurality of pores which form a microstructure. When a cross-section of the microstructure is observed with a scanning electron microscope, the number of the pores appearing on the cross-section is more than 250 or more per 6000 ?m2, an average area of the pores appearing on the cross-section is 5 ?m2 or less, and an average aspect ratio of the pores appearing on the cross-section is 0.55 or less.

Abstract: An apparatus and method for forming a densified carbon-carbon composite. The apparatus includes: a green part molding station for forming a green part; a carbonization station for carbonizing the green part; and an impregnation station for impregnating the carbonized part with a substantially curing by-product free, high carbon yield resin. The impregnation station includes a mold forming a sealed enclosure configured in the shape of the carbonized part for receiving the carbonized part and a vacuum source for evacuating the mold. At least one resin injection port is in the mold and a supply of substantially curing by-product free, high carbon yield resin is connected to the resin injection port for injection into the mold. In the preferred embodiment, the substantially curing by-product free, high carbon yield resin is a cyanate ester having a viscosity of less than about 100 cps at 250° F. and a carbon yield value of greater than about 60 wt. %.

Abstract: A ceramic brake lining which is reinforced with carbon fibers and has a matrix which consists essentially of silicon carbide together with silicon and/or carbon, wherein the reinforcing fibers used are long fibers having a mean length of at least 10 mm which are aligned in the plane parallel to the friction surface, a process for its production and its use in combination with brake discs made of C/SiC or CFC or as lining in friction clutches.

Abstract: A porous inorganic membrane comprises at least one inorganic phase having separating properties. Said membrane has a carbon content representing 0.05% to 25% by weight with respect to the mass of said inorganic phase and is selective to non-condensable gases. It is obtained by means of a selectivation treatment of a porous carbon-free inorganic membrane using a hydrocarbon feed. It is used in processes for separating non-condensable molecules such as hydrogen, and in association with a catalyst in a catalytic membrane reactor.

Abstract: A mixture of carbon-containing fibers, such as mesophase or isotropic pitch fibers, a suitable matrix material, such as a milled pitch is compressed while resistively heating the mixture to form a carbonized composite material. Preferably, the carbonized material has a density of at least about 1.30 g/cm3. Preferably, the composite material is formed in less than ten minutes. This is a significantly shorter time than for conventional processes, which typically take several days and achieve a lower density material. A treating component may be impregnated into the composite. Consequently, carbon/carbon composite materials having final densities of about 1.6–1.8 g/cm3 or higher are readily achieved with one or two infiltration cycles using a pitch or other carbonaceous material to fill voids in the composite and rebaking.

Abstract: A separator for a fuel cell is manufactured by preparing a raw material powder, uniformly mixing the prepared raw material to be formed into a slurry, and charging the raw material powder derived from granulation into a metal mold for heat press forming. The raw material is obtained by adding to carbon powder a binder containing a mixture of phenolic resin and epoxy resin. Therefore the heat press forming step does not cause the binder to generate gas, thus allowing manufacturing of a separator exhibiting sufficient gas-impermeability.

Abstract: A carbon baking furnace comprising a refractory lined kiln defining a baking path, further comprising a means for substantially continuously receiving green carbon articles, means for packing said green carbon articles in a sacrificial medium, a means for substantially continuously displacement of the packed carbon articles through said baking path and a means for substantially continuously removing baked carbon articles from the kiln.

Abstract: Provided are an amorphous coke for a special carbon material characterized in that it is an amorphous coke obtained by blending a coal tar base heavy oil and/or a petroleum base heavy oil with a resin and subjecting the mixture to thermal decomposition polycondensation; it has a larger thermal expansion coefficient than that of a coke obtained from a heavy oil alone; and a molded article of the coke is shrunk by 0.3% or more in terms of a volume change rate before and after the treatment when it is subjected to graphitizing treatment, and a production process of an amorphous coke for a special carbon material characterized in that in subjecting a coal tar base heavy oil or a petroleum base heavy oil to thermal decomposition polycondensation, the raw material is blended with a resin to modify a coke crystal structure.

Abstract: A method produces components from high-temperature-proof fiber reinforced composite ceramics from tapes containing carbon fibers. Heating and simultaneously compacting under the influence of pressure and temperature produces a force-locking connection in the region of the contact zones. The prebody is carbonized. At least one post-compaction of the prebody is followed by a carbonization of the prebody, in which the tapes are separated from the adjoining tapes in the region outside the contact zones by graphite spacers and inserted into a clamping device. The clamping device is made substantially of graphite. As a result, the tapes and the prebody that is formed therefrom are securely fixed during the processing steps. The components can be utilized as workpiece carriers, carriers for optical components, and in the aerospace field.

Abstract: Molding apparatus for rapid transfer of molten resin or pitch in an infiltration molding process. The apparatus includes e.g. an extruder (4) for melting and conveying a resin or pitch and a mold (10) arranged so that resin or pitch is conveyed to a mold insert cavity (19) within the mold. The mold insert contains an internal protrusion such as a locating ring (25) for positioning a porous body (1, 18) within the mold insert cavity in a position that brings about unidirectional flow of the molten resin or pitch through the porous body. Also, rapid resin or pitch infiltration molding process that includes injecting a high melting point, high viscosity, molten resin or pitch into the mold to effect a unidirectional impregnation of a heated preform via a pressure gradient in the mold.

Abstract: A process is described for the production of holes, particularly of micro-perforations, in a composite material, constituted by fibers embedded in a resinous matrix, characterized in that it consists in a preliminary step of carrying out on a specimen of the composite material, with the help of a laser beam, tests consisting in adjusting the duration of illumination at a predetermined place on the specimen, as well as the focusing and power of said laser beam, so as to confine the temperature in the mass of the material to a range of temperatures both greater than the thermal decomposition temperature of the matrix resin and below the temperature of altering the physical properties of the fibers, so as to carry out the elimination of the resin without affecting the physical integrity of the fibers, then in reproducing on the material (8) to be treated, at each position of a perforation to be made, the operating conditions of the laser (10, 12) so as to constitute in said material a through passage, as a resul

Abstract: A process for preparing graphite articles is presented. In particular, the process includes employing a particulate fraction comprising at least about 35 weight percent coke, coal or combinations thereof having a diameter such that a major fraction of it passes through a 0.25 mm to 25 mm mesh screen. The particulate fraction is mixed with a liquid or solid pitch binder, to form a stock blend; the stock blend is extruded to form a green stock; the green stock is baked to form a carbonized stock; and the carbonized stock is graphitized. The stock blend further comprises one or both of carbon fibers (advantageously added after mixing of the particulate fraction and pitch has begun) and small particle size filler (advantageously added as part of the particulate fraction).

Abstract: A mixture of carbon-containing fibers, such as mesophase or isotropic pitch fibers, a suitable matrix material, such as a milled pitch is compressed while resistively heating the mixture to form a carbonized composite material. Preferably, the carbonized material has a density of at least about 1.30 g/cm3. Preferably, the composite material is formed in less than ten minutes. This is a significantly shorter time than for conventional processes, which typically take several days and achieve a lower density material. A treating component may be impregnated into the composite. Consequently, carbon composite materials having final densities of about 1.6-1.8 g/cm3 or higher are readily achieved with one or two infiltration cycles using a pitch or other carbonaceous material to fill voids in the composite and rebaking.

Abstract: A battery electrode plate (19) is produced via an active material impregnation step for impregnating an entire porous core substrate shaped like a thin plate (1) with an active material (3), a pressing step for performing press working on the core substrate to form a plurality of rail shaped protrusions (8), an active material removal step for removing the active material to form core substrate exposed sections (13) by applying ultrasonic vibrations to the rail shaped protrusions, a flattening step for compressing the core substrate exposed sections down to an identical level with the other sections, and a cutting step for cutting predetermined sections including the core substrate exposed sections.

Abstract: A carbon microrod that holds a fine object by chemically adsorbing the object on the surface to make a dynamic measurement possible. An organic substance that leaves, after firing, glassy carbon that hardly becomes graphite, such as a chlorinated vinyl chloride resin, is mixed with a fine graphite powder having an average particle size of 1 ?m, and the mixture is extrusion molded with a die having a diameter of 50 ?m; the molded article is fired to give a carbon microrod comprising glassy carbon and crystalline carbon.

Abstract: A method for producing a glass-like carbon pipe is provided. The method comprises the steps of producing a plurality of thermosetting resin molded articles by centrifugal molding, said molded articles each having the shape of the sections of a pipe divided in the longitudinal direction and each provided with threaded or fitting portions; integrating these molded articles by joining at the threaded or fitting portions; and carbonizing the joined pipe to thereby produce a glass-like carbon pipe. This method is capable of producing a straight or bent pipe with excellent mechanical strength and gas sealability at the joint, and this method enables production of a pipe at a low cost since no machining is required for providing the threaded or fitting portions.

Abstract: A method of making a low friction bearing for use when immersed in a liquid particularly water is provided comprising a synthetic resin composition which includes powders of a rice bran ceramic, carbon rice bran ceramic or both which are uniformly dispersed in a synthetic resin. The weight ratio between the RBC or CRBC powders and the synthetic resin is 30:90 to 70:10.

Abstract: A ceramic material suitable for use in production of paving tiles, construction tiles, flooring in offices, flooring in machinery plants and so forth is obtained by a method comprising steps of mixing defatted bran derived from rice bran with a thermosetting resin before kneading, subjecting a kneaded mixture thus obtained to a primary firing in an inert gas at a temperature in a range of 700 to 1000° C., pulverizing the kneaded mixture after the primary firing into carbonized powders, kneading the carbonized powders with which ceramic powders, a solvent, and a binder as desired are mixed into a plastic workpiece (kneaded mass), pressure-forming the plastic workpiece at pressure in a range of 10 to 100 MPa, and subjecting a formed plastic workpiece thus obtained again to firing in an inert gas atmosphere at a temperature in a range of 100 to 1400° C.

Abstract: A process produces a fiber-reinforced silicon carbide composite. The resulting composite has a high toughness where bundles of a reinforcing fiber are densely covered with glassy carbon derived from a resin to avoid deterioration of the strength, and it can easily be produced even in complicated shapes. Specifically, a fiber-reinforced silicon carbide composite is produced by preparing a fiber prepreg containing a powdered silicon and a resin and molding the prepreg to yield a green body having a desired shape, or laminating a fiber prepreg containing a resin and a woven fabric prepreg containing a powdered silicon and a resin in alternate order, and molding the laminate to yield a green body having a desired shape; carbonizing the green body at 900° C. to 1350° C. in an inert atmosphere; impregnating the carbonized body with a resin; firing the impregnated body again at 900° C. to 1350° C.

Abstract: A composite high temperature insulator (A) includes a planar layer (10) having anisotropic thermal conductivity properties. A second planar layer (12) is formed from a rigid insulation material, such as a carbonized mixture of carbon fibers and a binder. The second layer is coextensive with the first layer and is preferably bonded thereto by a carbonaceous cement (44). When used to insulate a heat source, such as a furnace (50), convective heat is directed back to the source by the reflective surface (16) of the inner, anisotropic layer (10). Heat which enters the anisotropic layer is dissipated evenly through the plane of the layer along a plurality of heat paths defined by a plurality of layers (14) of flexible graphite. Accordingly, heat which reaches the outer, second layer (12) results in fewer hot spots than occur with a conventional rigid insulation material, thereby reducing the total amount of insulation material required to achieve a desired level of thermal insulation.

Abstract: A mixture of carbon-containing fibers, such as mesophase or isotropic pitch fibers, and a suitable matrix material, such as a milled pitch, is compressed while resistively heating the mixture to form a carbonized composite material having a density of about 1.5 g/cm3, or higher. The composite material is formed in under ten minutes. This is a significantly shorter time than for conventional processes, which typically take several days and achieve a lower density material. Consequently, carbon/carbon composite materials having final densities of about 1.6-1.8 g/cm3, or higher are readily achieved with one or two infiltration cycles using a pitch or other carbonaceous material to fill voids in the composite and rebaking.

Abstract: The present invention provides a method of manufacturing an exfoliated graphite/phenol resin composite foam of a porosity of 50-95%, a density of 0.1-0.8 g/cm3, by forming under contact pressure or reduced pressure at a temperature of 140-200° C. a mixture comprising 100 parts by weight of powdered and/or crushed exfoliated graphite and 40-240 parts by weight of phenol resin; an exfoliated graphite/phenol resin composite foam obtained by the method; and a method of obtaining an exfoliated graphite/glassy carbon composite foam of a porosity of 50-95%, a density 0.1-0.8 g/cm3 with volumetric baking shrinkage of 10% or less by baking the exfoliated graphite/phenol resin composite foam.

Abstract: A mixture of carbon-containing fibers, such as mesophase or isotropic pitch fibers, and a suitable matrix material, such as a milled pitch, is compressed while resistively heating the mixture to form a carbonized composite material having a density of about 1.5 g/cm3, or higher. The composite material is formed in under ten minutes. This is a significantly shorter time than for conventional processes, which typically take several days and achieve a lower density material. Consequently, carbon/carbon composite materials having final densities of about 1.6-1.8 g/cm3, or higher are readily achieved with one or two infiltration cycles using a pitch or other carbonaceous material to fill voids in the composite and rebaking.

Abstract: An oxidation resistant carbon composite material comprises nanocrystalline silicon carbide regions distributed throughout a carbon matrix. The composite is prepared by intermixing in a solvent a silicon carbide precursor and a carbon precursor and forming a solution that is free of solids. After removing the solvent from the mixture, the remaining material is pyrolyzed and forms the characteristic nanocrystalline silicon carbide in a carbon matrix. A composite made by the subject method and a part made from the composite are also provided.

Abstract: A fiber-reinforced silicon carbide composite is produced by preparing a fiber prepreg containing a powdered silicon and a resin and molding the prepreg to yield a green body having a desired shape, or laminating a fiber prepreg containing a resin and a woven fabric prepreg containing a powdered silicon and a resin in alternate order and molding the laminate to yield a green body having a desired shape; carbonizing the green body at 900° to 1350° C. in an inert atmosphere; subjecting the carbonized body to reaction sintering at a temperature of 1300° C. or more in vacuo or in an inert atmosphere to form open pores; and infiltrating molten silicon into the sintered body having open pores at a temperature of about 1300° to 1800° C. in vacuo or an inert atmosphere.

Abstract: A porous material suitable for use in a bearing rolling element. The porous material is obtained by a process which includes mixing degreased bran derived from rice bran with a thermosetting resin before kneading, subjecting a kneaded mixture to a primary firing in an inert gas at a temperature in a range of 700 to 100° C., pulverizing the kneaded mixture after the primary firing into carbonized powders sieved through a screen of 100-mesh, mixing the carbonized powders or the carbonized powders and ceramic powders with a thermosetting resin before kneading, pressure-forming a kneaded mixture thus obtained at a pressure in a range of 20 to 30 MPa, and applying a heat treatment again to a formed kneaded mixture in the inert gas at a temperature in a range of 100 to 1100° C.

Abstract: The present invention relates to carbon-matrix composites, such as carbon-carbon composites, and a method for forming them by forming a fabric of fusible and infusible fibers which can be processed and carbonized to form a composite. The methods disclosed herein permit preparation of composites which are particularly thin, uniform, and highly pure. The invention also relates to preprocessed fabrics and precarbonized composites, such as those comprising carbon or oxidized polyacrylonitrile fibers and fusible polyacrylonitrile fibers.

Abstract: A resin transfer molding (RTM) process is disclosed for rapidly filling a fibrous preform and/or a rigid, porous body with high viscosity resin or pitch. The process is suitable for impregnated multiple porous bodies stacked in a single mold. The process uses a fibrous preform or rigid porous body which is placed into a mold matching the desired part geometry. A resin is injected into the mold at temperature and pressure. After cooling, the infiltrated component is removed from the mold. The mold is constructed from two halves fitted to form at least one mold cavity. A gate fitted with a nozzle is set into one of the mold halves, and a valve admits resin or pitch into the gate area. Venting or vacuum can be applied to the mold. The mold is held in a hydraulic press and an extruder, optionally fitted with an accumulator, supplies molten resin or pitch to the mold.

Abstract: A voltage nonlinear resistor is composed of an aggregate of silicon carbide particles doped with impurities, in which oxygen and at least one of aluminum and boron are diffused in the vicinity of the surfaces of the silicon carbide particles, the diffusion length of the oxygen is about 100 nm or less from the surfaces of the silicon carbide particles, and the diffusion length of at least one of the aluminum and the boron is in the range of about 5 to 100 nm from the surfaces of the silicon carbide particles. A method for fabricating a voltage nonlinear resistor and a varistor using a voltage nonlinear resistor are also disclosed.

Abstract: An molded product of activated carbon produced by molding a kneaded mixture containing an activated carbon, a solvent, and a phenol-aldehyde type resin being solid in a normal temperature and containing 50 to 95% by weight of components soluble in the solvent used, drying and curing the molding, and then carbonizing the molding in an inert gas has a high adsorption capability and a high mechanical strength, e.g., a compressive strength, especially the strength after being contacted with an acid or water.

Abstract: A carbon fiber reinforced carbon composite, obtained by a method comprising impregnating a pitch or a resin into a molded member formed of carbon fibers for densification thereof; forming an impregnated pyrolytic carbon layer by CVI after densification; and forming a coated pyrolytic carbon layer on the impregnated pyrolytic carbon layer by CVD; a method of making the carbon fiber reinforced carbon composite; and a pulling single crystal member made from the carbon fiber reinforced carbon composite.

Abstract: There is provided a porous material suitable for use in a bearing retainer, having such properties as a small contraction ratio of the dimensions of a formed workpiece to those of a finished product, excellent hot oil resistance, small contraction change, insusceptibility to damage, light weight, a long service life, and ability to retain oil and grease for a long period of time. The porous material suitable for use in the bearing retainer is obtained by a process comprising the steps of mixing degreased bran derived from rice bran with a thermosetting resin before kneading, subjecting a kneaded mixture to a primary firing in an inert gas at a temperature in a range of 700 to 1000° C.

Abstract: An apparatus and method for forming a densified carbon-carbon composite. The apparatus includes: a green part molding station for forming a green part; a carbonization station for carbonizing the green part; and an impregnation station for impregnating the carbonized part with a substantially curing by-product free, high carbon yield resin. The impregnation station includes a mold forming a sealed enclosure configured in the shape of the carbonized part for receiving the carbonized part and a vacuum source for evacuating the mold. At least one resin injection port is in the mold and a supply of substantially curing by-product free, high carbon yield resin is connected to the resin injection port for injection into the mold. In the preferred embodiment, the substantially curing by-product free, high carbon yield resin is a cyanate ester having a viscosity of less than about 100 cps at 250° F. and a carbon yield value of greater than about 60 wt. %.

Abstract: A carbon-carbon composite material is made by providing an open-celled carbon foam preform, and densifying the preform with carbonaceous material. The open-celled carbon foam preform may be oxygen stabilized prior to carbonization, and the foam preform densified by CVD, HIP, PIC, VPI, pitch and resin injection, or any combination thereof. The carbon-carbon composite material can be heat treated to provide thermal management materials, structural materials, or a friction material for use in a brake or clutch mechanism.

Abstract: A process for manufacturing a brake lining made of a fiber-reinforced ceramic C/SiC material includes (1) producing a carbon fiber body having at least one of a defined volume of pores and capillaries; (2) infiltrating the carbon fiber body with at least one of carbon or a carbon precursor; (3) pressing the infiltrated carbon fiber body, thereby forming a green compact; (4) pyrolyzing the green compact, thereby forming a porous C/C body; (5) adjusting at least one of a pore and a capillary volume of the porous C/C body to maximally approximately 60% by volume; and (6) infiltrating the C/C body with liquid silicon so that carbon, at least in an area of pores and capillaries which is close to the surface, becomes silicon carbide.

Abstract: A composite material article reinforced with high strength short graphite fibers and having a matrix substantially consisting of silicon carbide is prepared which has an elongation at break of 0.25 to 0.5% and thus exhibits quasi-ductile failure behavior. The short reinforcing graphite fibers are enclosed by at least two shells of graphitized carbon which have been obtained by impregnation with carbonizable impregnating agents and subsequent carbonization. The shell closest to the graphite fibers contains no cracks. The outermost shell is partially converted into silicon carbide. The starting material used comprises long or short fiber prepregs, which are first carbonized, then subjected at least once to an operation consisting of impregnation with a carbonizable impregnating agent and recarbonization, then graphitized at a temperature of up to a maximum of 2400° C. and then comminuted to yield a dry material for the production of a precursor article.

Abstract: Methods of making a graphite material are provided. A flexible graphite is ground into a powder. The graphite powder is mixed with a resin and the mixture is hot pressed. A second method of making a graphite material is provided where the graphite is ground into a powder; the graphite powder is soaked in a cryogenic liquid; the soaked graphite powder is then expanded; the expanded soaked graphite powder is mixed with a graphite powder; and the graphite powder mixed with a resin are hot pressed. According to a third method, the flexible graphite is ground into a powder; the graphite powder is soaked into a cryogenic liquid, the soaked graphite powder is expanded; and the expanded soaked graphic powder is ground into a fine powder. The resulting graphite powder is mixed with a resin. The graphite powder mixed with the resin is hot pressed. According to a fourth method, graphite flakes are soaked into an acid; the soaked graphite flakes are expanded; and the expanded soaked graphite flakes are precompacted.