Abstract: Disclosed is a method of fabricating a graphite sheet, including: polymerizing diamines and a dianhydride to form a polyamic acid. The polyamic acid is solvent casted on a substrate and hot baked to form a polyamic acid film or gel film. The polyamic acid film or gel film is biaxially stretched at a high temperature imidization or chemical imidization to form the polyimide film. The polyimide film is then carbonized and graphitized to form a graphite sheet. The diamines include a diamine of Formula 1 and a diamine of Formula 2, and the dianhydride includes a dianhydride of Formulae 3, Formula 4, Formula 5, Formula 6, Formula 7, Formula 8, Formula 9, or combinations thereof.

Abstract: Disclosed is a carbon structure electrode for redox flow batteries, which includes a plurality of spherical macropores formed on a surface of a polymer-derived carbon structure and inside the polymer-derived carbon structure so as to allow electrolyte migration. The carbon structure electrode for redox flow batteries has excellent electrical conductivity and enables cost reduction through a simplified preparation process.

Abstract: Disclosed herein is a method for producing an elongated (rolled) carbonaceous film by polymer pyrolysis while suppressing the fusion bonding and the rippling of the carbonaceous film. The method for producing a carbonaceous film includes the step of heat-treating a polymer film wound into a roll, wherein the heat treatment is performed after the polymer film is wound into a roll at a temperature lower than a pyrolysis onset temperature of the polymer film so that the roll of polymer film has a center and has a space inside its cross-sectional circle (50% cross-sectional circle) (space within 50% cross-sectional circle) whose center is at the center and whose circumference passes through a point at which a length of the polymer film from an inner end thereof is 50% of a total length of the polymer film and that an area of the space within 50% cross-sectional circle is 25% or more of an area of the 50% cross-sectional circle.

Abstract: A technique of forming a carbon-carbon composite material may include infusing pyrolysis oil into a porous preform, polymerizing at least some components of the pyrolysis oil infused in the preform to form a phenolic resin, and pyrolyzing the phenolic resin to form a partially densified preform. Carbon-carbon composites formed from porous preforms in which pyrolysis oil comprising a phenolic compound and at least one of an aldehyde or ketone compound is disposed in pores of the preform are also described.

Abstract: In a method for producing a carbonaceous film in which a polymer film is wrapped around a core and is subjected to a heat treatment, material film surfaces during the carbonization step are prevented from fusion, whereby a long carbonaceous having a large area film is obtained. Fusion can be prevented by subjecting a polymer film to a heat treatment under a reduced pressure, and under a reduced pressure while allowing an inert gas to flow. The range of the pressure reduction is preferably ?0.08 MPa to ?0.01 kPa. It is preferred to carry out carbonization with the pressure reduced in the range of from ?0.08 MPa to ?0.01 kPa while allowing an inert gas to flow.

Abstract: The embodiments described herein pertain generally to a porous carbon particle and a producing method of the porous carbon particle, the producing method includes a step of polymerizing an aromatic monomer to form a polymer particle; a step of cross-linking the polymer particle; a step of coating a silica on a surface of the cross-linked polymer particle; a step of carbonizing the polymer particle coated with the silica.

Abstract: The carbon-carbon composite material is obtained by densification with a pyrolytic carbon matrix originating from a precursor in gaseous state at least in a main external phase of the matrix, and, at the end of the densification, final heat treatment is performed at a temperature lying in the range 1400° C. to 1800° C.

Abstract: There is provided a graphite composite film including a graphite film and a metal layer formed on a surface of the graphite film, in which peeling-off of the metal layer from the graphite film is suppressed. More specifically, the graphite composite film includes a graphite film and a metal layer formed on at least one side of the graphite film, wherein the graphite film has a plurality of through holes formed therein, a metal layer is formed also inside the through holes so as to be connected to the metal layer formed on a surface of the graphite film, the metal layer inside the through holes is formed continuously from the one side to an opposite side of the graphite film, and a distance between outer diameters of the through holes is 0.6 mm or less and a ratio of an area of metal inside the through holes to an area of the graphite composite film is 1.4% or more.

Abstract: A disposal method for entirely recycling solid refuse includes the following steps: sorting, crushing, drying, pressing with high pressure to shaped articles, producing charcoal from combustible refuse in high temperature and firing incombustible refuse in high temperature, at last cooling high temperature articles to obtain solid fuel with various shapes and bricks or board used for building. The method achieves entirely recycling house refuse, especial solid refuse. The method recycles solid refuse to obtain fuel and building material with economic value. The method is simple and its processing cost is low.

Abstract: The present invention relates to a production method for a glassy carbon mold, and, more specifically, relates to a production method for a glassy carbon mold including the steps of: placing a mixture having a thermosetting resin, a curing agent, and a viscosity adjusting solvent between a thermosetting resin substrate and a master pattern formed by a micro-nano process; pressing either the master pattern or the thermosetting resin substrate and applying heat to form a cured thermosetting resin pattern part on the substrate; and removing the master pattern, and subjecting the substrate and the cured thermosetting resin pattern.

Abstract: In an example of the surface coating method, an aromatic resin or a polycyclic aromatic hydrocarbonate is dissolved in an organic solvent to form a solution. A film precursor is formed on a surface of an electrode material by immersing the electrode material into the solution, and evaporating the organic solvent. The electrode material is selected from the group consisting of an electrode active material particle and a pre-formed electrode. The film precursor is exposed to i) a thermal treatment having a temperature equal to or less than 500° C., or ii) ultraviolet light irradiation, or iii) both i and ii, to carbonize the film precursor to form a carbon film on the surface of the electrode material. Also disclosed herein is a method for improving electrochemical performance of an electrode for a lithium based battery.

Abstract: Disclosed herein is a production method capable of efficiently producing a carbonized film wound into a roll without the occurrence of fusion bonding between the layers of the film. The method includes a carbonization step in which a polymer film wound around a core is placed in a heating furnace and carbonized by heat treatment to obtain a carbonized film wound around the core. The carbonization step is performed by increasing a temperature of the heat treatment from an initial temperature through a pyrolysis onset temperature to a pyrolysis end temperature. In the carbonization step, the heating furnace is decompressed when the temperature of the heat treatment is lower than the pyrolysis onset temperature, and after the temperature of the heat treatment reaches the pyrolysis onset temperature, the heating furnace is not decompressed or the heating furnace is decompressed so that an absolute pressure in the heating furnace is in a range of 21.3 kPa to 101.29 kPa.

Abstract: Method for manufacturing a friction disk including preparing a mixture including a carbide-forming element having an average particle size ?2,000 ?m, a resin, optionally a binder, and optionally fine carbon, and/or short carbon fibers; forming the mixture at ? to 280° C. to produce a molded body; heating the molded body to approximately 750° C. to approximately 1300° C. to form a porous carbon body including a carbon residue; heating the porous carbon body to a temperature above the melting point of the carbide-forming element thereby reacting the carbide-forming element with at least a portion of the carbon residue to yield an alveolar structure; infiltrating the alveolar structure with silicon at a temperature above the melting point of silicon thereby filling at least one pore of the alveolar structure with silicon and reacting the silicon with an amount of unreacted carbon residue to form silicon carbide; and obtaining a friction disk.

Abstract: Provided are organosilica composites based on bis(3-triethoxysilylpropyl)tetrasulfide (TESPTS) or bis(3-triethoxysilylpropyl)disulfide (TESPDS) and containing octadecyltrimethoxy silane (C18TMS) and cetyltrimethylammonium bromide (CTAB), and a method for preparing hollow or porous carbon structures and silica structures using the same. According to the present disclosure, it is possible to obtain hollow or porous carbon structures and silica structures in a more simple and cost-efficient manner. Thus, the resultant structures have a high surface area and a large mesopore volume, so that they may serve as catalyst carriers for fuel cells capable of loading metal catalyst particles having a smaller particle size in a larger amount and in a more homogeneously dispersed state.

Abstract: Process for producing a ceramic composite structure includes impregnating a reinforcing material with a suitable precursor slurry composition including thermosetting resin, a suitable curing agent, a ceramic component, a carbonaceous solids component, and optionally, a suitable solvent. Exemplary thermosetting resins include polyesters, vinyl esters, epoxy resins, bismaleimide resins, and polyimide resins. The carbonaceous solids component provides a suitable amount of carbon char upon pyrolization. The preform may be dried prior to curing to remove solvents and thereby provide a working material comprising up to 70 volume % solids. The preform is cured, pyrolized, and infiltrated with molten silicon to form a composite article. The thermosetting resin is selected for processibility, green strength, and relatively fast cure cycle.

Abstract: A process for obtaining granules for manufacturing a silicon carbide based sintered product, includes a) mixing a powder of silicon carbide SiC particles, whose average diameter d50 is at least about 2 micrometers with a powder of a boron compound particles, whose average diameter d50 is at least about 2 micrometers, the SiC particles content being more than 90% by weight of the powder mixture; b) co-milling the powder mixture until the overall average diameter d50 of the resulting particles is between 0.3 and 1 micrometers; c) chemically treating the powder mixture by base solution and acid wash; d) mixing the powder mixture of c) with 1 to 10% by weight, based upon the silicon carbide content, of a carbon containing resin having a water miscibility of more than 10:50, as measured according to the ISO8989 standard, and e) spray-drying the resulting mixture of d), to generate the granules.

Abstract: A graphite film excelling in heat conductivity, especially, a graphite film of high heat conductivity that even when its thickness is large, would not suffer damage by heat treatment. There is provided a process for producing a graphite film, including graphitizing a raw material film of a polymer film and/or carbonized polymer film, characterized by including (i) holding the raw film in a vessel capable of direct passage of current through voltage application and (ii) applying voltage to the vessel to thereby induce electrification so that graphitization is carried out. There is further provided a process for producing a graphite film, characterized by including the step of holding the raw material film in vessel (A) being electrifiable, subsequently holding the resultant vessel (A) in vessel (B) being electrifiable and effecting current passage through the whole so that graphitization is carried out.

Abstract: Methods of making a carbon-carbon composite preforms, particularly suitable as brake discs in aircraft landing systems, by combining titanium carbide particles ranging in size from 0.01 to 10 microns in diameter, resinous binder, and carbon fibers or carbon fiber precursors in a mold, and subsequently subjecting the combined components to pressure and heat to carbonize the resinous binder by methods, thereby providing the carbon-carbon composite preform having particulate titanium carbide uniformly distributed throughout its mass. Prior to combining the titanium carbide and the binder with the fibers in this process, the particulate titanium carbide may be mixed with liquid binder, the resulting TiC/binder mixture may then solidified, and the resulting solid TiC/binder mixture may be ground into a fine powder for use in the process. Also, compositions for preparing a carbon-carbon composite friction materials, and methods of improving wear and dynamic stability in a carbon-carbon composite brake discs.

Abstract: In a method for producing a carbonaceous film in which a polymer film is wrapped around a core and is subjected to a heat treatment, material film surfaces during the carbonization step are prevented from fusion, whereby a long carbonaceous having a large area film is obtained. Fusion can be prevented by subjecting a polymer film to a heat treatment under a reduced pressure, and under a reduced pressure while allowing an inert gas to flow. The range of the pressure reduction is preferably ?0.08 MPa to ?0.01 kPa. It is preferred to carry out carbonization with the pressure reduced in the range of from ?0.08 MPa to ?0.01 kPa while allowing an inert gas to flow.

Abstract: An insulating sheet has a heterogeneous laminated structure, and includes a graphene sheet and a hexagonal boron nitride sheet on the graphene sheet, the hexagonal boron nitride sheet having a root mean square (RMS) surface roughness of about 0.5 nm or less in a region having an area of about 200 nm×200 nm or less, and one or more of longitudinal and transverse lengths of about 1 mm or more.

Abstract: The present invention is a preparation method for asphalt-based spherical activated carbon which requires no infusibilization process. Placing coal tar asphalt into a melting device; introducing compressed air of 0.1 MPa-0.5 MPa into the device and stirring until a melting temperature of 280° C.-350° C. is reached; continuing for 2-8 hours until the base material has a softening point of 200° C.-260° C.; after cooling down, pulverizing the base material to obtain asphalt powder. Obtaining 34%-79% by mass of carbon powder, 1%-10% by mass of binder, and 20%-65% by mass of the asphalt powder and then forming spherical particles with a diameter of 0.5 mm-5 mm with the carbon powder, the binder and the asphalt powder at room temperature. Introducing the spherical particles of asphalt directly into an asphalt carbonization furnace for carbonization at a temperature of 600° C.-900° C. under protection of an inert gas to obtain asphalt spherical carbon.

Abstract: The present invention provides to a preparation of a yarn with coffee residue. The present invention also provide to a novel yarn with coffee residue.

Abstract: A conductive mesoporous carbon composite comprising conductive carbon nanoparticles contained within a mesoporous carbon matrix, wherein the conductive mesoporous carbon composite possesses at least a portion of mesopores having a pore size of at least 10 nm and up to 50 nm, and wherein the mesopores are either within the mesoporous carbon matrix, or are spacings delineated by surfaces of said conductive carbon nanoparticles when said conductive carbon nanoparticles are fused with each other, or both. Methods for producing the above-described composite, devices incorporating them (e.g., lithium batteries), and methods of using them, are also described.

Abstract: In order to obtain a graphite film having an excellent thermal diffusivity, a high density, and excellent flatness without flaws, recesses and wrinkles on the surface, the process for producing a graphite film according to the present invention comprises the graphitization step for a raw material film made of a polymer film and/or a carbonized polymer film and/or the post-planar pressurization step for the film in this order to prepare a graphite film, wherein the graphitization step is a step of thermally treating two or more stacked raw material films at a highest temperature of 2,000° C. and includes a method of electrically heating the raw material films themselves and/or a method of thermally treating the films while applying pressure to the films planarly, and the post-planar pressurization step includes a method of planarly pressurizing the one raw material film or the multiple stacked raw material films after graphitization by single-plate press or vacuum press.

Abstract: In order to provide an inexpensive product composed of a porous carbon provided with electrochemical active material, said product being suitable particularly for use as a cathode or anode material for a secondary battery, a process comprising the following process steps is proposed: (a) producing a template from inorganic material by gas phase deposition, said template comprising a framework of pores and nanoparticles joined to one another, (b) coating the template framework with an electrochemical active material or a precursor thereof, (c) infiltrating the pores of the template with a precursor substance for carbon, (d) carbonizing the precursor substance to form a carbon layer, (f) removing the template.

Abstract: In the manufacture of carbon-carbon composite brake discs, migration of anti-oxidant substances into the friction surfaces is prevented by limiting or eliminating surface porosity in the carbon-carbon composite brake materials. The method includes infusing a suitable resin into pores in surface layers of the carbon-carbon composite disc and then charring the resin-infused disc to convert the resin in the pores to pyrolytic carbon. The resin may be infused into the carbon disc by submerging the disc in a molten resin. Prior to submerging the disc in the molten resin, the disc may subjected to a vacuum to remove air from the pores. While the disc is submerged in the molten resin, the pressure in the pressurizable vessel may increased to force the molten resin into the open porosity of the disc.

Abstract: It is possible to obtain a graphite film with its shape controlled, by performing a sag controlling step of controlling temperatures of a polymer film at both widthwise ends and a temperature of the polymer film in a widthwise middle portion within a temperature range from a starting temperature of thermal decomposition of the polymer film to a sag controlling temperature of the polymer film.

Abstract: A method produces carbon fiber-reinforced coke. Carbon fiber-reinforced plastic (CFRP) materials derived from components and semi-finished products are continuously fed through a top side of the drum of a delayed coker as a partial flow or as a main flow, and the CFRP materials sink through the gas phase into the still liquid phase. The carbon fibers are released through carbonization of the resin matrix and incorporated therein during the coking process. The decomposition products of the resin matrix are supplied to a material recovery process.

Abstract: There is provided a porous, carbon-containing preform, including a body (CL) of unidirectional carbon fiber fabrics (C1), and a friction layer (FL) of randomly-arranged-carbon-fiber fabrics (F1), combined with the body (CL) by a needle-punching operation. According to the present invention, it is by the needle-punching operation that the friction layer (FL) of the randomly-arranged-carbon fiber fabric (F1) is formed on the body (CL) of the unidirectional carbon fiber fabric (C1) and the friction layer (FL) of the randomly-arranged-carbon-fiber (F1) is cross-linked to the body (CL) of the unidirectional carbon fiber fabric (C1) in producing the porous, carbon-containing preform.

Abstract: The invention relates to a process for preparing a composition comprising 10 to 45% of the total solids weight lignin, polyacrylonitrile or a polyacrylonitrile copolymer, and a solvent to form a lignin-based polyacrylonitrile-containing dope and the resulting products. The dope can be processed to produce fibers, including precursor, oxidized and carbonized fibers. The oxidized fibers are of value for their flame resistant properties and carbonized fibers are suitable for use in applications requiring high strength fibers, or to be used to form composite materials.

Abstract: Disclosed is a composite form-member including: a hollow metal form-member with holes formed through the inner and the outer surface of the form-member; and a coated layer filling the holes and laminated on the inner and outer surfaces of the form-member, the coated layer is made of an organic fiber material with carbon, and a welding portion comprising an exposed outer circumferential surface portion without the coated layer laminated thereon, and a method of manufacturing thereof.

Abstract: A process for producing a graphite cage for an anti-friction bearing, which cage holds a plurality of anti-friction elements. A cage injection molding is injected in an injection molding process from a mass which contains carbon mesophase powder, and this cage injection molding is subsequently heat-treated in order to transform the carbon from the mesophase into pure graphite.

Abstract: A ball joint prosthesis can include a shell, having an outer articular surface of a first material and an open distal end, configured to receive a sealing receptacle. A volume of a second material, within the shell, can be more compressible than the first material. The ball joint prosthesis can have an effective compressibility that is intermediate between a compressibility of the first material and a compressibility of the second material.

Abstract: A first and a second object are joined with the aid of a joining element including at least in the region of its distal and proximal ends a thermoplastic material. Two blind holes facing each other are provided in the two objects and the joining element is positioned in the blind holes such that its distal and proximal ends are in contact with the bottom faces of the blind holes and such that there is a gap between the two objects. This assembly is then positioned between a support and a sonotrode. The sonotrode and the support are forced towards each other, while the sonotrode is vibrated, thereby liquefying at least part of the material having thermoplastic properties, there, where the joining element ends are pressed against the bottom faces of the holes and allowing the liquefied material to infiltrate into pores.

Abstract: A method of forming a graphitic carbon body employs compression and resistance heating of a stock blend of a carbon material and a binder material. During molding of the body, resistance heating is accompanied by application of mechanical pressure to increase the density and carbonization of the resulting preform body. The preform can then be subjected to a graphitization temperature to form a graphite article.

Abstract: In some examples, a method for densifying a material via pitch comprises inserting the material to be densified into a mold, wherein the mold is part of an apparatus. The apparatus may include a ram configured to apply a ram pressure sufficient to force a pitch into the mold to densify the material, a gas source configured to apply a gas pressure sufficient to force the pitch into the mold to densify the material, and a vacuum source operable to create a vacuum pressure in the mold at least prior to application of either the ram pressure or the gas pressure. The method may further comprise densifying the material in the mold via pitch using a selectable one of the ram, the gas source, the ram and the vacuum source, or the gas source and the vacuum source.

Abstract: Disclosed herein is a method for producing an elongated (rolled) carbonaceous film by polymer pyrolysis while suppressing the fusion bonding of the carbonaceous film. The method for producing a carbonaceous film includes the step of heat-treating a polymer film wound into a roll, wherein the heat treatment is performed after the polymer film is wound into a roll to have a gap between adjacent layers of the polymer film at a temperature lower than a pyrolysis onset temperature of the polymer film so that the roll of polymer film as a whole satisfies a relationship that a value obtained by dividing a thickness of a gap between adjacent layers of the polymer film (Ts) by a thickness of the polymer film (Tf) (Ts/Tf) is 0.16 or higher but 1.50 or lower.

Abstract: Methods and compositions relate to manufacturing a carbonaceous article from particles that have pitch coatings. Heating the particles that are formed into a shape of the article carbonizes the pitch coatings. The particles interconnect with one another due to being formed into the shape of the article and are fixed together where the pitch coatings along adjoined ones of the particles contact one another and are carbonized to create the article.

Abstract: A method allows for preparation of CNT nanocomposites having improved mechanical, electrical and thermal properties. Structured carbon nanotube forms such as sheet, yarn, and tape are modified with ?-conjugated conductive polymers, including polyaniline (PANI), fabricated by in-situ polymerization. The PANI modified CNT nanocomposites are subsequently post-processed to improve mechanical properties by hot press and carbonization.

Abstract: A graphite film excelling in heat conductivity, especially, a graphite film of high heat conductivity that even when its thickness is large, would not suffer damage by heat treatment. There is provided a process for producing a graphite film, including graphitizing a raw material film of a polymer film and/or carbonized polymer film, characterized by including (i) holding the raw film in a vessel capable of direct passage of current through voltage application and (ii) applying voltage to the vessel to thereby induce electrification so that graphitization is carried out. There is further provided a process for producing a graphite film, characterized by including the step of holding the raw material film in vessel (A) being electrifiable, subsequently holding the resultant vessel (A) in vessel (B) being electrifiable and effecting current passage through the whole so that graphitization is carried out.

Abstract: A refractory, which is particularly suitable for use in an inner lining of a blast furnace, is obtainable by a process. The process includes providing a mixture containing coke, silicon and a binder. A green block is formed from the mixture. The green block is then baked. The baked block is semi-graphitized at a temperature between 1600 and 2000° C.

Abstract: Exemplary embodiments provide methods and apparatus of forming fibrous carbon foams (FCFs). In one embodiment, FCFs can be formed by flowing a fuel rich gas mixture over a catalytic material and components to be encapsulated in a mold to form composite carbon fibers, each composite carbon fiber having a carbon phase grown to encapsulate the component in situ. The composite carbon fibers can be intertwined with one another to form FCFs having a geometry according to the mold.

Abstract: A carbon/carbon part and a process for making carbon/carbon parts is provided. The process involves forming steps, carbonization steps and densification steps. The forming steps may include needling fibrous layers to form fibers that extend in three directions. The carbonization steps may include applying pressure to increase the fiber volume ratio of the fibrous preform. The densification steps may include filling the voids of the fibrous preform with a carbon matrix.

Abstract: The problem of the present invention is to provide, in high current-low energy type ion implantation apparatuses, a graphite member for a beam line inner member of an ion implantation apparatus, which graphite member can markedly reduce particles incorporated in a wafer surface. This problem can be solved by the graphite member of the present invention, which is a graphite member for a beam line inner member of an ion implantation apparatus, which member having a bulk density of not less than 1.80 Mg/m3 and an electric resistivity of not more than 9.5 ??·m. Preferably, the R value obtained by dividing D band intensity at 1370 cm?1 by G band intensity at 1570 cm?1 in the Raman spectrum of a spontaneous fracture surface of the graphite member is not more than 0.20.

Abstract: A porous carbon sheet obtained by binding separate carbon short fibers with a carbonization product of a resin, wherein the pore mode diameter of the sheet is 45 to 90 ?m and the mean fiber diameter of the carbon short fibers is 5 to 20 ?m. The sheet can be produced by thermoforming a precursor fiber sheet comprising carbon short fibers of 15 to 30 g/m2 in basis weight and a thermosetting resin of 30 to 80 g/m2 in basis weight by hot plates having a certain clearance and carbonizing the thermosetting resin contained in thermoformed precursor fiber sheet.

Abstract: A system for making carbon foam anodes including a digestion vessel in communication with a coal feedstock unit for producing a digested coal; a mold having an interior for accepting the digested coal to produce an ungraphitized carbon foam anode having a desired shape; a pressure unit in communication with the mold for producing an increased pressure within the interior of said mold; a heating element in communication with the mold to provide heat to the mold sufficient to convert the digested coal into the ungraphitized carbon foam anode; and a graphitization oven for graphitizing the ungraphitized carbon foam anode to produce the carbon foam anode. The present invention further includes methods for making carbon foam anodes.

Abstract: A carbon monolith includes a robust carbon monolith characterized by a skeleton size of at least 100 nm, and a hierarchical pore structure having macropores and mesopores.

Abstract: Disclosed is a tin-carbon mesoporous composite for a lithium ion battery negative electrode material, and a method for preparing the same. Using a mesoporous molecular sieve as a template, the precursors of tin and carbon are caused to fill the mesopores of the template and carbonized under nitrogen to obtain a composite of stannic oxide and carbon, and the stannic oxide is encapsulated by the carbon; and then the tin-carbon mesoporous composite for lithium ion battery negative electrode material is obtained by hydrothermal treatment, carbonization, etching, and high temperature carbothermic reduction. The tin-carbon mesoporous composite for lithium ion battery negative electrode material synthesized in the present invention has a reversible capacity of 550 mAh·g?1, after 100 cycles at a current density of 500 mA·g?1.

Abstract: According to the present invention, a porous electrode substrate with greater sheet strength, lower production cost, and excellent gas permeability and conductivity as well as its manufacturing method are provided. Also provided are a precursor sheet for forming such a substrate, and a membrane electrode assembly and a polymer electrolyte fuel cell containing such a substrate. The method for manufacturing such a porous electrode substrate includes the following steps [1]˜[3]: [1] a step for manufacturing a sheet material in which short carbon fibers (A) are dispersed; [2] a step for manufacturing a precursor sheet by adding a water-soluble phenolic resin and/or water-dispersible phenolic resin to the sheet material; and [3] a step for carbonizing the precursor sheet at a temperature of 1000° C. or higher.

Abstract: A carbon composite braking band or rotor for a disc brake has at least one strengthening ring, made of carbon-carbon material, located near or at a potential cracking point of the braking band.