Abstract: The present invention provides diamond tools, and a method for the formation thereof, using CVD techniques. In one aspect, an ephemeral mold is provided which has a diamond interface surface configured to inversely correspond to the desired shape for the working surface of a diamond layer in a tool. After the mold is provided, various CVD techniques may be used to deposit diamond layers upon the diamond interface surface of the mold. Following diamond deposition upon the diamond interface surface, the mold may be removed by various means, such as chemical etching, etc. Thus, the working surface of the diamond receives a shape which inversely corresponds to the configuration of the mold's diamond interface surface. The diamond mass may then be incorporated into a tool, if such incorporation has not yet taken place.

Abstract: According to the present invention, carbon foams are produced largely in accordance with the methods described in U.S. patent application Ser. No. 09/902,828, but with starting materials that comprise from about 10 to about 90% by weight of ground petroleum pitch and from about 90 to about 10% by weight of bituminous coal particulate exhibiting a free swell index of from about 3.5 to about 5.0.

Abstract: A method for the manufacture of coal-based carbon foams from a coal particulate starting material that comprises blending from 1 to about 10% by weight of pitch with the coal particulate before foaming. Blends of coal-based particulate with 1 to about 10% by weight of pitch as well as coal-based carbon foams manufactured from such blends are also described.

Abstract: The method includes the preparation of a preimpregnated product that undergoes a heat treatment between 70 and 1100 deg. C., is embedded with an inert substance that comprises a charge and a polymeric binder in a quantity greater than the volume of the voids of the single-layer yarn which is calculated by means of the formula [1], where mn is the mass of inert substance, dn is the density of the inert substance, a is the length of the preimpregnated product, b is the width of the preimpregnated product, h is the thickness of the preimpregnated product, mpr is the mass of the preimpregnated product, and dfib is the density of the fibre, and is heated between 160 deg. C. and 200 deg. C., a pressure of between 1 and 5 MPa being applied simultaneously.

Abstract: A rocket motor ablative material (e.g., an insulation liner, bulk material, or the like) of this invention is formed from, as a precursor of the carbon reinforcement structure, one or more polyarylamides configured as a suitable reinforcing structure, such as a yarn, flock, and/or felt. Aramid yarns can be prepared by twisting/spinning aramid filaments, and/or by carding and yarn-spinning staple aramid fibers. In particular, the insulation may be used, for example, for a rocket motor nozzle or as a rocket motor heat shield subjected to conditions comparable to those of continuous filament viscose rayon.

Abstract: The present invention relates to a method for continuous production of elongated carbon bodies, particularly carbon electrodes which are produced in direct connection with the smelting furnace wherein the electrodes are consumed, where a metallic casing containing unbaked carbonaceous electrode paste comprising a particulate solid carbon material and a carbonaceous binder is continuously or substantially continuously lowered through a baking furnace which is heated to a temperature between 500 and 1200° C.

Abstract: A composite body of silicon carbide having binderless, allotropic carbon granules distributed throughout is produced. The nominal size of the binderless allotropic carbon granules can range from 5 to 500 micrometers. The concentration of the binderless allotropic carbon particles can vary from 1.0 to 35.0 weight percent. The process to produce such a composite body is to sinter silicon carbide with binderless, carbon-yielding precursor granules. The composite body is utilized in tribological applications. The dense, impervious silicon carbide-binderless carbon composite exhibits excellent physical and tribological characteristics when used as a mechanical face seal, a sliding bearing arrangement, or some other rubbing component.

Abstract: A method for preparing a refractory carbide component includes the steps of providing a carbon rich polymer precursor to silicon carbide and excess carbon, determining an amount of excess carbon in the carbon rich polymer precursor, combining the carbon rich polymer precursor with a selected amount of refractory metal to form a precursor/metal mixture, the selected amount being selected so as to provide stoichiometrically equivalent amounts of the excess carbon and the refractory metal, forming the mixture into a preform of a propulsion component, and heating the preform so as to thermally degrade the carbon rich polymer precursor to produce the silicon carbide and the excess carbon, the excess carbon and the refractory metal reacting to form refractory metal carbide and provide the refractory carbide component.

Abstract: The present invention provides a carbon heating element having an arbitrary specific resistance and an arbitrary shape which are arbitrary necessary as a heating element, and a method of producing the same. The carbon heating element is obtained by uniformly dispersing one or at least two metal or metalloid compounds into a composition having shapability and showing a high yield of a carbon residue after firing, shaping the dispersed material-containing mixture thus obtained, and firing the shaped material under a nonoxidizing atmosphere.

Abstract: A process form producing ceramic composites comprising metal carbides, which comprises the steps production of a porous carbon-containing intermediate body, infiltration of the intermediate body with the melt of a carbon-forming metal, reaction of at least part of the carbon of the intermediate body with the carbide-forming metal to form a metal carbide, with at least part of the carbide-formed metal being supplied via at least one wick made of porous carbon material having pore channels and the wick being produced by carbonization of wood materials or of essentially unidirectionally reinforced CFRP, such wicks and their use in the abovementioned process

Abstract: Process for producing hollow bodies comprising fiber-reinforced ceramic materials, where mold cores whose shape corresponds to that of the hollow spaces are produced in a first step, at least one mold core together with a press moulding composition or formable fiber composition are introduced into a mold, where the press moulding composition comprises carbon fibers and/or carbon filaments and thermally curable carbonizable binders, in such a way that the position of the cores corresponds to the desired position of the hollow spaces to be formed in a second step, the composition is cured in a third step by heating to a temperature of from 120° C. to 280° C., to give a green body, the strengthened green body is carbonized and or graphitized in a fourth step by heating in a nonoxidizing atmosphere to a temperature of from about 750° C. to about 2400° C.

Abstract: Exemplary silicon carbide ceramic bodies are produced according to the invention. An exemplary ceramic body includes silicon carbide in major amounts and an organic gelation agent in a minor amount. An exemplary ceramic body exhibits sufficient density and hardness to function as body armor.

Abstract: An apparatus for forming a non-woven mat of nanofibers by using a pressurized gas stream comprises a first member having a supply end defined by one side across the width of said first member and an opposing exit end defined by one side across the width of said first member; a second member having a supply end defined by one side across the width of said second member and an opposing exit end defined by one side across the width of said second member, the second member being located apart from and adjacent to said first member, the length of said second member extending along the length of said first member, said exit end of said second member extending beyond said exit end of said first member, wherein said first and second members define a first supply slit; and a third member having a supply end defined by one side across the width of said third member and an opposing exit end defined by one side across the width of said third member, said third member being located apart from and adjacent to said first me

Abstract: A method for preparing a refractory carbide component includes the steps of providing a carbon rich polymer precursor to silicon carbide and excess carbon, determining an amount of excess carbon in the carbon rich polymer precursor, combining the carbon rich polymer precursor with a selected amount of refractory metal to form a precursor/metal mixture, the selected amount being selected so as to provide stoichiometrically equivalent amounts of the excess carbon and the refractory metal, forming the mixture into a preform of a propulsion component, and heating the preform so as to thermally degrade the carbon rich polymer precursor to produce the silicon carbide and the excess carbon, the excess carbon and the refractory metal reacting to form refractory metal carbide and provide the refractory carbide component.

Abstract: An improved submerged entry nozzle is provided which is useful in the casting of aluminum killed molten steel. The nozzle has an improved slagline sleeve or collar which surrounds the outer portion of the nozzle to protect it from corrosion during the casting process. The slagline sleeve is made from resin bonded zirconia/graphite which has been formulated so that upon curing of the resin to form resite, there is a reduction in the contractile tendency which results in a reduction in stress fracturing. The reduction of the contractile tendency and the resulting resistance to stress fracturing is achieved by adding an effective amount of calcium oxide to the resin-zirconia-graphite mixture which is used to form the sleeve.

Abstract: A process for producing a carbon material for an electric double layer capacitor electrode, including activating a graphitizable carbon or a graphitizable carbon source to have its pore volume in the range of 0.6 to 1.5 cm3/g, and imparting mechanical impact force to the graphitizable carbon or the graphitizable carbon source activated in the activating step to reduce the pore volume to at most 75% of that before the mechanical impact force is imparted.

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 process for producing molded pitch based foam is shown which provides a more uniform density gradient throughout the ultimate product. The process utilizes a pressure drop during processing in order to induce foaming. By inducing foaming through process depressurization, additional viscosity manipulation can be achieved as well as improved density gradient characteristics in the ultimate product.

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 process for forming a silicon carbide structure includes molding by compression a mixture of a silicon precursor powder and a cross-linking thermoset resin to form a rigid structure, carbonizing the rigid structure, and forming a silicon carbide structure by heating the carbonized rigid structure at a temperature sufficient to allow carbon and silicon in the structure to react to form silicon carbide.

Abstract: The incorporation or blending of from about 1 to about 10% by volume of a “carbide precursor” powder, preferably on the order of <100 microns in size, with a coal particulate starting material and the subsequent production of carbon foam in accordance with the method described herein, results in a carbon foam that exhibits significantly enhanced abrasive characteristics typical of those required in the polishing of, for example glass, in the manufacture of cathode ray tubes.

Abstract: A method and apparatus for combining raw fibrous and binding materials in a single mixing step (Step S3), followed by consolidation (Step S5) so as to greatly shorten the overall cycle time to a finished fiber-reinforced composite part. Chopped fibrous materials and binder materials are deposited sequentially onto a belt conveyor (Step S2) so that the materials are successively layered, one on top of each other in a predetermined ratio, and subsequently mixed (Step S3) to achieve uniform dispersion throughout. The mixed materials are then deposited into a rotating mold (Step S4) to further ensure uniform dispersion of fibrous and binder materials. Impregnation of the fibrous materials with the binder material occur in-situ as the uniformly mixed materials are heated and subsequently compacted in the mold (Step S5) to obtain the desired shape of the fiber-reinforced composite part.

Abstract: A method for manufacturing bodies containing reinforcing fibers includes mixing fibers, fiber bundles, or fiber agglomerates with at least one binder that can be carbonized to form a molding material; and compressing the molding material to form bodies containing reinforcing fibers with a mold having inserts. The resulting bodies have recesses with lateral edges corresponding to the inserts such that the reinforcing fibers are oriented approximately parallel to the lateral edges of the recesses.

Abstract: A composite, contains substrate fibers, and carbon ion exchanger, on the substrate fibers. The fiber provides a support to the carbon ion exchanger, resulting in excellent mechanical properties, compared to carbon fiber ion exchangers.

Abstract: A method for making micrometer-sized carbon tubes is disclosed. A natural or synthetic fiber is first coated with a thermally stable coating material to form a coating layer over the fiber. Such coated fiber is then employed for making a hollow carbon tube, by removing the fiber and carbonizing the coating layer together with the residue of the fiber (if there is any). The removing treatment and carbonization treatment can be proceeded sequentially or concurrently.

Abstract: The carbon fiber precursor fiber bundle of the present invention is an acrylonitrile-based fiber bundle wherein the ratio of the length and width of the fiber cross section of a monofilament (length/width) is 1.05 to 1.6, and the amount of Si measured by ICP (Inductively Coupled Plasma) atomic emission spectrometry is in the range of 500 to 4,000 ppm. This type of carbon fiber precursor fiber bundle has a high compactness, and the carbonizing processing ability is good. Furthermore, for the carbon fiber bundle which is to obtained hereafter, the resin impregnating ability and tow spreading ability are good, the strength increases, and it has bulkiness. Furthermore, the carbon fiber precursor fiber bundle of the present invention is an acrylonitrile-based fiber bundle wherein the liquid content ratio HW is 40 wt. % or more and less than 60 wt. %.

Abstract: A method for producing shaped articles of ceramic composites provides a high degree of dimensional tolerance to these articles. A fiber preform is disposed on a surface of a stable formed support, a surface of which is formed with a plurality of indentations, such as grooves, slots, or channels. Precursors of ceramic matrix materials are provided to the fiber preform to infiltrate from both sides of the fiber preform. The infiltration is conducted under vacuum at a temperature not much greater than a melting point of the precursors. The melt-infiltrated composite article substantially retains its dimension and shape throughout the fabrication process.

Abstract: The invention relates to a method for obtaining artificial graphite powder for electrical engineering, manufacturing synthetic diamonds and in other fields of technology with especially high requirements for graphite purity. The novelty of the inventive method is the use of pyrolytic carbon material obtained by methane pyrolysis at a temperature of 2100-2400° C. Pyrolytic carbon obtained as a waste product of pyrolytic anisotropic material can be used as a carbon material. The method includes grinding carbon material and its graphitizing at a temperature of 2600° C.-2700° C. The inventive method simplifies the process of preparing artificial graphite powder and enhances the degree of graphitization, which improves the quality of the final product.

Abstract: An improved structural reinforcement system for ceramic composite parts fabricated with polymeric ceramic precursor resins includes a mechanically interlocked mat of carbon or graphite filaments with a semi-random orientation. The carbon or graphite mat has a density of at least about 15% filaments by volume. Using graphite mat yields finished ceramic components that exhibit substantial ductility without the use of interfacial coatings, as well as good structural strength and even distribution of thermal energy.

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: An activated carbon molded body, more particularly in honeycomb form and for use as an adsorption filter, can be produced from a mixture including activated carbon, water, novolak powder, clay, cellulose ether, liquid starch, wax, polyacrylamide and soap, by a procedure involving thoroughly mixing the constituents, extruding the mixture to form a monolithic molded body and cutting same to size, drying the body and effecting pyrolysis thereof. The adsorption filter produced therefrom can be regenerated by electrical heating under specified conditions.

Abstract: An improved submerged entry nozzle is provided which is useful in the casting of aluminum killed molten steel. The nozzle has an improved slagline sleeve or collar which surrounds the outer portion of the nozzle to protect it from corrosion during the casting process. The slagline sleeve is made from resin bonded zirconia/graphite which has been formulated so that upon curing of the resin to form resite, there is a reduction in the contractile tendency which results in a reduction in stress fracturing. The reduction of the contractile tendency and the resulting resistance to stress fracturing is achieved by adding an effective amount of calcium oxide to the resin-zirconia-graphite mixture which is used to form the sleeve.

Abstract: Exemplary silicon carbide ceramic bodies having inclusions therein are produced according to the invention. An exemplary ceramic body includes silicon carbide in major amounts and unreacted particles of an additive in minor amounts which are bonded to the matrix. The particles are dispersed throughout the silicon carbide, and are preferably selected from one or more of the group consisting of boron nitride, aluminum nitride and titanium diboride.

Abstract: Carbon fiber bundles may be dispersed into substantially single mono-filaments in pitch by stirring a mixture of fibers and pitch at a temperature at which the pitch has a viscosity of about 0.1 to about 5 poise. The resulting fiber pitch binder contains about 0.5 to about 10.0 wt. % carbon fibers substantially dispersed as substantially single mono-filaments which are randomly oriented which may then be used directly as a binder for producing carbon bodies, for example, graphite electrodes, pinstock or specialty graphite articles. This unique binder using an economical amount of carbon fibers has the capacity to increase the strength and reduce the coefficients of thermal expansion of the resulting carbon products in more than one direction due to the random orientation of the carbon fibers.

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: A porous carbon body is produced from a carbon felt with a low level of metal impurity by forming the body from a carbon felt with a low level of metal impurity, and infiltrating the body with silicon. In another aspect of the invention, an annealing furnace is treated with a halide-containing gas at elevated temperature to scavenge metal impurities. A porous carbon body is then infiltrated with silicon in the annealing furnace.

Abstract: An electrode for secondary battery made of carbon material is provided, which is light in weight while excellent in charge-discharge properties and in durability in repetitive use. A material for electrode is obtained by intermixing a synthetic resin with vapor-phase growth carbon fibers to make the vapor-phase growth carbon fibers uniformly dispersed in the synthetic resin to obtain a mixture, molding the mixture into a predetermined shape to obtain a molded product, and heating the molded product at high temperature to convert it into a carbon-carbon composite material. The electrode for battery is made of thus obtained carbon-carbon composite material.

Abstract: Fluid diffusion layers with favorable mechanical and electrical properties are prepared for fuel cell electrodes by impregnating a porous carbonaceous web with a carbonizable polymer having pyrrolidone functionality and then carbonizing the pyrrolidone polymer. The polymer having pyrrolidone functionality is stabilized against vaporization by use of an oxidization step prior to carbonization. The fluid diffusion layers are particularly suitable for use as gas diffusion layers in solid polymer electrolyte fuel cells.

Abstract: A heat-resistant adhesive with excellent adhesion strength and an adhesion method using the adhesive which includes an easily carbonizable resin such as a polycarbodiimide resin and, as necessary, a powdery filler (e.g. graphite powder, carbon powder, coke powder etc.) and a pitch.

Abstract: A method of making carbon-carbon pistons and a limited variety of other products also requiring light weight, high strength and high thermal conductivity, and the resulting piston, including the steps of feeding impregnated fibers from spools into a layered bundle of fibers, coating the fibers with a carbonaceous material to form a preform, sleeving the preform with a thermoplastic sleeve, extruding the coated preform, passing the preform through an oven while compacting the preform further, and cutting the preform into standard lengths as the preform exits the furnace and achieves a degree of cool down. The pistons are machined from the cut preforms with the piston axis parallel to the fibers and layers. The pistons include crown, skirt, and wrist pin bosses and the axis of the wrist pin bosses is perpendicular to the fibers and layers.

Abstract: A method and apparatus for extruding pitch based foam is disclosed. The method includes the steps of: forming a viscous pitch foam; passing the precursor through an extrusion tube; and subjecting the precursor in said extrusion tube to a temperature gradient which varies along the length of the extrusion tube to form an extruded carbon foam. The apparatus includes an extrusion tube having a passageway communicatively connected to a chamber in which a viscous pitch foam formed in the chamber paring through the extrusion tube, and a heating mechanism in thermal communication with the tube for heating the viscous pitch foam along the length of the tube in accordance with a predetermined temperature gradient.

Abstract: To realize constituent elements for realizing a nonaqueous secondary battery having high energy density and high repeating stability, and a nonaqueous secondary battery using the same.

Abstract: Disclosed is a negative active material for a rechargeable lithium battery that includes graphite particles, silicon micro-particles attached on the graphite particles and a carbon film partially or totally coated on the graphite particles.

Abstract: An optical filter using alternating layers of materials with “low” and “high” indices of refraction and deposited with atomic layer control has been developed. The multilayered thin film filter uses, but is not limited to, alternating amorphous layers of atomically controlled Si (n=3.56) as the high index material and diamond-like carbon (DLC, n=2.0) as the low index material. The Si layers are grown with a self-limiting pulsed molecular beam deposition process which results in layer-by-layer growth and thickness control to within one atomic layer. The DLC layers are produced using an ion-based process and made atomically smooth using a modified Chemical Reactive-Ion Surface Planarization (CRISP) process. Intrinsic stress is monitored using an in-situ cantilever-based intrinsic stress optical monitor and adjusted during filter fabrication by deposition parameter modification.

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 mesophase pitch material having a melting point in excess of 350° C. has a solvent added thereto to provide a solvated mesophase pitch. A low molecular weight solvent is used so that the melting point can be brought low enough to create a carbon foam at a convenient temperature. The solvent is then removed by heat and/or vacuum and, consequently, the pitch reverts to a high melting point of approximately greater than 350° C. The pitch can then be heated or carbonized without an oxidative stabilization step. Alternatively, a solvated mesophase pitch material may be used initially for foaming.

Abstract: In order to impregnate a porous workpiece with a liquid impregnating agent, the pre-manufactured workpiece is arranged in an injection mould or diecasting mould and the liquid impregnating agent is introduced into the mould with the aid of a commercially available injection moulding or diecast moulding apparatus. To limit the need for post impregnation cleaning and/or shaping, the mould cavity is configured to closely fit the shape of the pre-manufactured workpiece. The impregnating agent may be a natural or synthetic lubricant, a plastic or, more commonly, a molten metal or metal alloy.

Abstract: A process for preparing carbon fibrils by contacting a source of carbon with a supported catalyst that includes at least one multivalent transition metal having a size of about 35 to 700 A deposited on an inorganic substrate having a size of up to about 400 microns.