Abstract: Graphite electrodes for the production of aluminum by carbothermic reduction of alumina are either submerged in the molten bath in the low temperature compartment or they are horizontally arranged in the side walls of the high temperature compartment. The electrodes are manufactured by using a mixture of coke particles covering the complete particle size range between 25 ?m to 3 mm and by using an intensive mixer to effectively wet all coke particles with pitch. The electrodes have a flexural strength of at least 20 N/mm2. By using a complete range (continuum) of particle sizes in conjunction with an intensive mixer, the geometric packing of the particles is significantly improved, hence the material density is increased and thus a higher mechanical strength as well as improved electrical conductivity in comparison to conventional graphite electrodes is achieved.

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 latent heat storage material is formed of at least two plies of a compressible graphitic material in which graphite wafers are arranged substantially in layer planes lying one on the other and which is infiltrated with at least one phase change material. The surface of each ply being provided with a structuring reaching the outsides of the graphite material. The evacuation and infiltration travel lengths in the layer planes, due to the structuring, amounts to a maximum of 200 mm.

Abstract: An inner lining for the steel shell of a carbothermic reduction furnace for the production of alumina has a base layer of graphite and a coating layer of refractory material. The refractory material is corundum (Al2O3) bound by Sialon (Si.Al.O.N). The lining structure provides protection against the molten slag and it is not attacked by the CO-rich melt furnace atmosphere. Further, the lining does not contaminate the melt and it provides an effective heat dissipation system in case of a power shut-off.

Abstract: Cathodes for aluminum electrolysis cells are formed of cathode blocks and current collector bars attached to those blocks. The cathode slots receiving the collector bar are lined with expanded graphite lining thus providing longer useful lifetime of such cathodes and increased cell productivity. The expanded graphite provides a good electrical and thermal conductivity especially with its plane layer.

Abstract: Carbon electrodes have at least one socket with an internal thread to be mated with a threaded pin having at least one external thread. Also such a threaded pin is provided for connecting to such carbon electrodes. The internal thread or external thread of the carbon electrodes and/or the pins are provided with non-load bearing abutment thread windings.

Abstract: A bipolar cooling plate module used in fuel cell stacks contains an anode-side terminal plate and a cathode-side terminal plate, in which at least one of the surfaces of the two terminal plates facing towards one another contains coolant channels. The two terminal plates are fixed to one another by an integral sealing element. The sealing element contains a sealing bead that surrounds the coolant distribution structure and seals the gap between the cooling surfaces of the two terminal plates. A compressible two-dimensional conducting element is inserted between the terminal plates, which extends only over the region of the cooling surfaces enclosed by the sealing groove, in which the coolant distribution structure is located. The element has a compression reserve that is sufficient to compensate for the shrinkage in thickness caused by cooling, of the sealing bead.

Abstract: A method for producing aluminum and a method for producing a graphite electrode for a carbothermic reduction furnace, in which aluminum is produced by carbothermic reduction of alumina, render the graphite electrode substantially gas-impermeable. The graphite electrode is consumed during furnace operation and electrode columns connected by graphite pins are fed continuously fed in from the top into the furnace. The coating of the electrode withstands a temperature of up to 300° C. and more over a period of several hours without oxidation. Since the coating enters the furnace compartment at least partially, it is configured so that it will not contaminate the hot melt. That is, the chemistry of the coating materials is similar to the ingredients of the overall reaction or, at a minimum, the amount of foreign elements is very low. The coating is provided so that it does not increase the electrical contact resistance at the connection between the electrode columns and the electrode holding clamps.

Abstract: A joining assembly includes metallic, ceramic, polymeric and/or fiber-reinforced components, which have at least one joining surface with at least one recess and/or raised area with an undercut. The joining assembly also includes a joining element that conforms in size and shape to the recess and/or the raised area of the components to be joined and has at least one flexible rim area. The flexible rim area can be placed in a form-locking and force-locking interconnection with the recesses and/or raised areas of the components to be joined. A method for joining components is also provided.

Abstract: A bicycle disk brake rotor which is rigidly joined to the hub and can be brought into a frictional engagement with a caliper secured to the bicycle. The rotor has an inner annular region, which is joined positively and nonpositively to the hub, and an outer annular region, while the inner and outer annular region are connected by webs and the bicycle disk brake is made entirely of composite material consisting of silicon-infiltrated carbon fiber composite of a fabric structure consisting of endless fibers with a phase distribution of >60% C and 20-30% SiC.

Abstract: Clutch linings comprising fiber-reinforced ceramic materials which contain short carbon fibers and whose matrix has a mass fraction of at least 40% of silicon carbide, process for producing them and their use in clutch systems, in particular for motor vehicles.

Abstract: In a method of making a body part or chassis part of a motor vehicle, several pre-impregnated fiber materials (prepregs) are stacked on top of one another, with an outermost prepreg intended for attachment to a metallic base body being provided with an adhesive. The stacked prepregs are then shaped into a three-dimensional preform which is then compressed with the base body in a press tool for bonding the preform with the base body and allowing the adhesive to harden, thereby producing a joined structure which is allowed to cure.

Abstract: A process is described for generating hydrogen through the oxidation of fuels that contain chemically bound hydrogen, in particular hydrocarbons, having the following process steps: a) introducing the fuel (1) as well as the oxidation agent (2) into a reactor (3) having a porous material (4?) that is embodied in such a way that flame propagation in a direction opposite the direction of flow is prevented, and b) reacting the fuel with the oxidation agent in partial oxidation so that hydrogen is obtained in gaseous form. In addition, an apparatus for generating hydrogen that has a reactor that contains a porous material (4, 4?), and the reactor (3) is embodied as a tubular reactor that has a central chamber (5) to introduce the fuel and the oxidation agent that extends in the axial direction and is delimited radially toward the outside by a first wall that has porous material (4), and the first wall is delimited radially toward the outside by a second wall that contains the porous material (4?).

Abstract: A workpiece carrier for the inductive heating of workpieces contains ceramic materials at least at bearing surfaces which come into contact with the workpieces. The ceramic materials are distinguished by a high dimensional stability, low thermal and electrical conductivity and a high resistance to thermal shocks. A process for producing a ceramic material for a workpiece carrier obtains a suitable ceramic material by infiltrating a porous carbon skeleton with silicon. Processes for inductive heating and inductive hardening of workpieces with the workpiece carrier are also provided.

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: Carbon-ceramic brake discs, the remaining porosity in which, after infiltration with a carbide-forming element and reaction of this element with at least part of the carbon in the preliminary body of the carbon-ceramic brake disc to form carbides, is at least partly filled with particles whose average diameter is in the range from 0.5 nm to 20 nm, and a process for producing carbon- ceramic brake discs with reduced porosity, wherein carbon-ceramic brake discs are treated with a solution of organic compounds of boron, zirconium, titanium, silicon or aluminum or mixtures of such compounds, the cited organic compounds being present as sols in an organic solvent, after removal from the sol bath the brake discs treated in this way are dried in an oven at a heating rate of between 30 K/h and 300 K/h under air or protective gas and are then tempered at a final temperature of between 350° C. and 800° C.

Abstract: A number of properties of polygranular carbon bodies can be improved by small quantities of carbon fibers being incorporated in the formulations for production of such bodies. However, it has proven difficult for carbon fibers to be introduced into the green mixture. Therefore, a high-grade coke, preferably needle coke, in accordance with the invention is used to produce the polygranular carbon bodies. This high-grade coke according to the invention contains the carbon fibers simply as a result of being produced in the delayed coker of a refinery. All the main details of the way in which a coke of this type is mixed into the green mixture correspond to the reliably managed processing of other needle cokes.

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 latent heat storage material is in the form of a composite material formed of a phase-change material to store latent heat and graphite flakes incorporated therein to improve thermal conductivity. The graphite flakes are distinguished by a high aspect ratio and a high anisotropy of thermal conductivity. The volume content of graphite flakes in the latent heat storage material is between 10 and 40%. The composite material can be obtained by mixing the components or infiltrating a bed containing graphite flakes with a liquid phase-change material. The graphite flakes are preferably aligned during mixing with the phase-change material by shaking or tamping, etc., so that the thermal conductivity in the direction that is advantageous for the individual application is maximized. A latent heat storage unit containing the material and processes for producing the material and the unit and processes for using the material, are also provided.

Abstract: In order to pull semiconductor single crystals by the Czochralski method, quartz glass crucibles are used which require support crucibles having high temperature capabilities. Such support crucibles may be made of various materials, in which case graphite materials, carbon fiber-reinforced carbon (CFC), combinations thereof or carbon materials coated with silicon carbide (SiC) are used. The working life of a CFC support crucible can be extended by a partial thickening of the support crucible walls affected by corrosion processes.