Abstract: The manufacture of powdered feed materials for hard fine grained metal body production includes the reduction of metal oxides into powdered metal and the subsequent carburization into metal carbide. Processes currently used are very cost intensive, mainly because of very long reaction times at high temperatures. According to applicant's economical process, the above reactions occur in the range of seconds and in a high-temperature cyclone as the reaction chamber. The apparatus is rather simple to construct. The stock to undergo reaction is continuously introduced into the chamber as a solid powdered phase with reaction gas and/or carrier gas, and passes through the chamber on predetermined paths for reaction, without leaving the solid state thereby.

Abstract: The preparation of suitable powdered metal is important in powder metallurgy technology. To date, powdered metals, in particular refractory metals, have been produced using very time-consuming and, consequently, costly methods for the reduction of metallic compounds, e.g. by reducing solid metallic compounds to powdered metal in fluidized bed ovens or pusher-type furnaces. In the present invention, powdered metallic compounds are reduced by retaining the solid phase as a continuous process by particles passing through a reaction chamber to predetermined orbits. The process lasts on average 0.4 to 60 s, and the level of completeness of the process is at least 90%.

Abstract: The invention relates to a hard solder for high-temperature soldered joints joining high temperature-resistant materials, especially chromium and alloys based on chromium. The hard solder consists of 40% to 70% by weight chromium, up to 2% by weight of one or several of the metals selected from the group of vanadium, niobium, tantalum, titanium, zirconium and hafnium, up to 2% by weight of one or several of the metals or their oxides selected from the group of rare earths and yttrium, as well as nickel as the balance. The solder according to the present invention is particularly suitable for joining by soldering parts in solid-electrolyte, high-temperature fuel cells.

Abstract: The invention relates to a chromium-based alloy which has a chromium content of more than 65% by weight and the following composition: 0.005 to 5% by weight of one or more oxides of the rare earth elements and 0.1 to 32% by weight of one or more metals selected from the group comprising iron, nickel and cobalt, the remainder being chromium.The alloy may furthermore contain up to 30% by weight of one ore more metals selected from the group comprising Al, Ti, Zr and Hf, up to 10% by weight of one or more metals selected from the group comprising V, Nb, Mo, Ta, W and Re and up to 1% by weight of C and/or N and/or B and/or Si.Compared with pure chromium the alloy has a substantially improved oxidation resistance and improved corrosion resistance, in particular with respect to vanadium pentoxide.

Abstract: A material for metal components, such as bipolar plates and window foils of high-temperature fuel cell systems, has ceramic solid electrolytes made of yttrium-stabilized zirconium oxide. The material includes a chromium alloy having from 3 to 10 atom % iron and from 0.5 to 5 atom % of rare earth metal and/or rare earth metal oxide, having a coefficient of thermal expansion at a temperature of 200.degree. C. amounting to from 8.5.times.10.sup.-6 to 10.5.times.10.sup.-6 per kelvin by which the temperature rises, and attaining a value at 900.degree. C. in a range from 14.times.10.sup.-6 to 15.times.10.sup.-6.

Abstract: The clutch disc for a motor vehicle friction clutch comprises a hub on which a driving disc provided with friction linings is coaxially rotatably mounted through a torsional vibration damper. The torsional vibration damper has two mutually relatively rotatable damper parts which are rotationally elastically coupled with one another through springs. One of the damper parts is guided rotatably on the hub through at least one rolling bearing. The rolling bearing reduces especially the friction occuring in idling operation.