Abstract: A synchronizing ring is composed of a composite material comprising a metallic layer consisting of aluminum alloy and having a thickness of 0.1 to 1.0 mm forming a friction cone and a steel backing layer having a thickness of 0.5 to 3.5 mm and cladded to the metallic layer. The invention also includes a process of manufacturing a synchronizing ring by metal forming.

Abstract: A composite bearing material for use in the manufacture of crankshaft bearings comprises a steel strip, which is provided on one side, which is to be used disposed on the outside of the bearing, with an elastic layer, and on the other side, which is to be disposed on the inside of the bearing, with a bearing metal layer. In order to effect a sound insulation, in a particularly desirable manner the elastic layer consists of halogen-free polymers.

Abstract: A material which is intended for use in sliding surface bearings comprises a metallic backing, a porous metallic substrate layer applied to said backing, and a PTFE-filler mixture, which completely fills the pores of the substrate layer and constitutes an antifriction layer. The bond strength between the antifriction layer and the substrate layer is improved by coating that surface of the substrate layer which faces the antifriction layer with a primer.

Abstract: A cast light metal piston for internal combustion engines is provided with a ceramic insert in those zones which are highly thermally stressed and/or for heat insulation. To form a high-strength bond between the light metal and the insert, high-strength fibers are embedded in the light metal in the zone adjoining the insert.

Abstract: In a light alloy piston having a convex and oval external shape, the piston skirt has in the cold state a larger running clearance at its top end than at its bottom end. In order to reduce the friction loss of such piston, the piston skirt has a larger ovalness adjacent to the horizontal plane extending through the pin axis than in the remaining regions of the piston skirt.

Abstract: A sheet material for sliding surface bearings comprises an expanded metal mesh which consists of a wrought aluminum alloy and is coated with a mixture of polytetrafluoroethylene, filler and glass fibers. The bond strength is increased by coating the surface of the expanded metal mesh with a primer layer.

Abstract: A composite piston for internal combustion engines has an interior cooling chamber and an outer cooling passage. An annular rib protrudes from the inside surface of the upper part and that surface of the lower part which faces that annular rib. An annular flange is clamped between said rib and said surface of the lower part. A tongue which protrudes into the cooling passage is provided on that edge of said flange which faces the cooling passage. In order to minimize the temperature of that surface of the cooling passage which is near the combustion chamber and to maintain at least adjacent to the uppermost ring groove a temperature which is sufficient to prevent a wet corrosion of the piston and of the piston rings, the tongue defines a relatively narrow annular gap with that surface of the cooling passage which is near the combustion chamber so that the coolant oil is throttled as it flows through that gap.