Abstract: Porous carbon fibers, whose active centers are formed by pores that are filled at least in part by carbon and/or metal and/or metal carbide, obtainable by carbonization of organic or inorganic polymers, the use thereof for the adsorption or separation of gaseous substances, in particular of CO2, and also a method for the production thereof. First, a spinning mixture containing polyacrylonitrile-based polymer A and an organic or metallo-organic polymer B is produced. Next, the spinning mixture is spun to form mixed fibers of polymer A and polymer B. The mixed fiber is stabilized by oxidation. This is followed by carbonization or graphitization of the mixed fiber under non-oxidizing conditions in such a way that the polymer B forms a carbon and/or metal and/or metal carbide residue of at least 22 wt %, the residue forming active centers.

Abstract: A brake system includes a friction coupling having organically or inorganically bound metal-containing, sintered-metal-containing and/or CFC-containing brake linings and a brake disc of fiber-reinforced C/SiC ceramic composite material. A friction layer and/or a surface of the brake disc subject to friction has a proportion of SiC greater than 65% and material compositions in a core region and a surface region of the brake disc are different. The brake system may be used in motor vehicles, rail vehicles or aircraft.

Abstract: The invention relates to the detection of oxidation of carbon-containing fibers or fiber bundles embedded in a nonconductive or semiconducting ceramic matrix in composites wherein use is made of the eddy current method.

Abstract: A fiber-reinforced composite body containing a first zone made of a ceramic matrix, which predominantly contains silicon carbide and, optionally, silicon and/or carbon and/or compounds thereof, and containing a second zone, which is located on a surface of the ceramic matrix zone and formed form a fiber-reinforced C/SiC ceramic. The fiber length decreases from the exterior of the fiber-reinforced ceramic zone up to the first zone and, optionally, up to one or more other zones that are arranged on the second zone. A method for producing the composite body is characterized by involving a joint infiltration at least of the first zone and of the second zone with liquid silicon and by the carrying out of a siliconization. A composite body of this type can be used, in particular, as armoring in the civil or military sectors.

Abstract: Porous carbon fibers, whose active centers are formed by pores that are filled at least in part by carbon and/or metal and/or metal carbide, obtainable by carbonization of organic or inorganic polymers, the use thereof for the adsorption or separation of gaseous substances, in particular of CO2, and also a method for the production thereof. First, a spinning mixture containing polyacrylonitrile-based polymer A and an organic or metallo-organic polymer B is produced. Next, the spinning mixture is spun to form mixed fibers of polymer A and polymer B. The mixed fiber is stabilized by oxidation. This is followed by carbonization or graphitization of the mixed fiber under non-oxidizing conditions in such a way that the polymer B forms a carbon and/or metal and/or metal carbide residue of at least 22 wt %, the residue forming active centers.

Abstract: A fiber-reinforced composite body containing a first zone made of a ceramic matrix, which predominantly contains silicon carbide and, optionally, silicon and/or carbon and/or compounds thereof, and containing a second zone, which is located on a surface of the ceramic matrix zone and formed form a fiber-reinforced C/SiC ceramic. The fiber length decreases from the exterior of the fiber-reinforced ceramic zone up to the first zone and, optionally, up to one or more other zones that are arranged on the second zone. A method for producing the composite body is characterized by involving a joint infiltration at least of the first zone and of the second zone with liquid silicon and by the carrying out of a siliconization. A composite body of this type can be used, in particular, as armoring in the civil or military sectors.

Abstract: A friction disc, in particular a brake or clutch disc, includes carbon fiber-reinforced ceramic composite material with at least one top surface formed as a friction surface. At least part of the friction surface is formed of a different material, in particular of a carbon-containing material. The different material exhibits lower wear and oxidation resistance than that of the rest of the friction surface and a supporting zone of the friction disc. A visual, audible or mechanical signal is produced under operating conditions due to comparatively greater wear. The signal provides a warning that the service life of the friction disc is being exceeded. A process for producing the friction disc is also provided.

Abstract: Process for producing hollow bodies comprising fibre-reinforced ceramic materials, where cores whose shape corresponds to that of the hollow spaces are produced in a first step, a green body is produced in a second step by introducing the abovementioned cores and a press moulding compound into a mould, where the press moulding compound comprises carbon fibres and/or carbon threads and pitch and/or resins, the green body is cured in a third step by heating under pressure, and then carbonised in a fourth step by heating in the absence of oxidants to form a C/C body, which latter can be infiltrated with liquid metal with retention of its shape in a fifth step, with at least partial formation of carbides, where the cores comprise a material which is non-meltable but undergoes at least sufficient shrinkage above the curing temperature of the shaping by pressing of the press moulding compound for the shrunken core to be able to be taken out from the carbonised body; hollow bodies produced by this process and also t

Abstract: Process for producing hollow bodies comprising fibre-reinforced ceramic materials, where cores whose shape corresponds to that of the hollow spaces are produced in a first step, a green body is produced in a second step by introducing the abovementioned cores and a press moulding compound into a mould, where the press moulding compound comprises carbon fibres and/or carbon threads and pitch and/or resins, the green body is cured in a third step by heating under pressure, and then carbonised in a fourth step by heating in the absence of oxidants to form a C/C body, which latter can be infiltrated with liquid metal with retention of its shape in a fifth step, with at least partial formation of carbides, where the cores comprise a material which is non-meltable but undergoes at least sufficient shrinkage above the curing temperature of the shaping by pressing of the press moulding compound for the shrunken core to be able to be taken out from the carbonised body; hollow bodies produced by this process and also t

Abstract: Process for producing shaped bodies comprising fiber-reinforced ceramic materials, where a green body is produced in a first step by introducing a press moulding composition into a mold, where the press moulding composition comprises carbon fibers and/or carbon filaments and pitch and/or resins which, when treated thermally and with the exclusion of oxidizing agents, form carbon-containing residues, the green body is cured in a second step by heating to a temperature of from 120° C. to 280° C. under pressure, the cured green body, also referred to as intermediate body, is carbonized in a third step by heating in a nonoxidizing atmosphere to a temperature of from about 750° C. to about 1100° C.

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: A large number of irrigation system devices connected to a common two-wire cable can be powered and individually controlled from a central location by transmitting over the cable DC pulses of alternating polarity. Control information is conveyed by transmitting a command pulse train consisting of a series of pulses, separated by short no-power intervals, whose polarities indicate logic ones or zeros. Following a command pulse train, a selected watering station decoder acknowledges receipt of instructions by drawing current during a predetermined pulse of an alternating-polarity power pulse cycle, while a sensor decoder returns binary data by drawing current during one or the other of the alternating-polarity pulses of a series of power pulse cycles.

Abstract: Process for producing shaped bodies comprising fiber-reinforced ceramic materials, where a green body is produced in a first step by introducing a press moulding composition into a mold, where the press moulding composition comprises carbon fibers and/or carbon filaments and pitch and/or resins which, when treated thermally and with the exclusion of oxidizing agents, form carbon-containing residues, the green body is cured in a second step by heating to a temperature of from 120° C. to 280° C. under pressure, the cured green body, also referred to as intermediate body, is carbonized in a third step by heating in a nonoxidizing atmosphere to a temperature of from about 750° C. to about 1100° C.

Abstract: Friction members are composed of a ceramic composite material. The friction members can be used for motor vehicles as a clutch disk for friction clutches, for transmitting motive power, or as a brake disk. A friction zone of the friction member is composed of ceramic, in particular of Si and SiC. A core zone of the friction member is made from fiber-reinforced C/SiC, in particular of long fiber woven fabric-reinforced and short fiber-reinforced C/SiC.

Abstract: A method is provided for producing a fiber-reinforced material which is composed, at least in a region of a surface layer, of a ceramic composite and has carbon-containing fibers reaction-bonded to a matrix containing the elements Si and C. In particular a method of producing fiber-reinforced silicon carbide is provided in which a structure of a matrix contains cracks and/or pores, at least at ambient temperature, because of a high thermal expansion coefficient compared with that of the fibers. Metals are selectively electrodeposited in the open pores and cracks of the matrix and, in particular, in a region of the electrically conductive reinforcing fibers. As a result, the open pores and cracks are filled and, in addition, metallic top layers are optionally formed that are firmly keyed to the ceramic composite and that may serve as an interlayer for glass top layers or ceramic top layers.

Abstract: A composite material includes a ceramic matrix and two different fractions of fiber bundles, namely a reinforcing fiber bundle fraction and a matrix fiber bundle fraction having different average fiber bundle lengths. The fractions of fiber bundles are separated in a total fiber bundle distribution relative to a fiber bundle length by a minimum. A method for manufacturing a composite material and a method for manufacturing elements formed of a composite material are also provided.

Abstract: Connecting pieces for carbon material electrodes include carbon fibers. The fibers are oxidatively activated carbon fibers which additionally have a carbonized coating. The carbonized coating is a carbonization product of a coating material selected from wax, pitch, natural resins, thermoplastic and thermosetting polymers.

Abstract: A multilayer ceramic composite is described which contains at least one supporting zone having oxidation-sensitive reinforcing fibers as well as a matrix. The matrix optionally contains oxidation-sensitive components. The composite further contains at least one surface layer, as well as at least one additional protective layer disposed between the supporting zone and surface layer, and whose matrix is composed substantially of at least one component of the matrix of the supporting zone or cover layer. The protective layer further contains additives that form self-healing layers.

Abstract: The invention relates to the detection of oxidation of carbon-containing fibers or fiber bundles embedded in a nonconductive or semiconducting ceramic matrix in composites wherein use is made of the eddy current method.

Abstract: Protection products and armored products made of a fiber-reinforced composite material with a ceramic matrix, include a protection element for partial or complete absorption of at least one impact-like load focussed at a point. The protection element has a body having at least one dimension at least equal to 3 cm, in a direction perpendicular to a load to be absorbed. The body includes a fiber-reinforced composite material having a ceramic matrix with at least 10% by weight of silicon carbide and having reinforcing fibers. At least 5% by weight of the reinforcing fibers are carbon fibers and/or graphite fibers.