Abstract The German Army is using the Sikorsky helicopter Typ CH-53 G in the marine version, this means that the tail with the rear rotor can be folded sidewise in order to safe space during storage. During flight the fuselage is locked by two gear racks that slide in the bore hole of an aluminium housing. Due to the high friction during the movement of the steel racks the inner bore surface is damaged of up to 1 mm depth. In this paper the repair of this inner surface of the bore by arc-wire spraying is described. A special gun extension was developed so that the narrow bore (diameter 48 mm; length 400 mm) can be repaired. Preliminary test results with various materials are presented. Paper text in German.

Abstract Sufficient electrical insulation must be ensured between the individual connection plates made of the ODS alloy in planar high-temperature fuel cells. In this paper, APS coatings and coating systems consisting of zirconium dioxide or zirconium dioxide/aluminum oxide are sprayed onto structured plates made of ODS-chromium alloy, qualified and implemented. The electrical insulation of both the coatings and the sealing glass composites is determined at 850 deg C and 950 deg C. The gas resistance of the coated sealing glass composite samples to air, hydrogen and hydrogen/water is determined experimentally. The coating technology is developed for small series production and successfully implemented on a large joined multi-cell unit with basic dimensions of 260 x 260 millimeter square. The paper demonstrates that this coating technology is sufficiently developed for industrial applications. Paper includes a German-language abstract.