Instandsetzung von verschleißgeschädigten Zylinderoberflächen durch Thermisches Spritzen (Repair of Damaged Cylinder Surfaces by Thermal Spraying)

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.