Patent ID: 8201831

Claim:
A piston ring comprising: a body with at least one running surface, a wear layer applied to the surface, the wear layer being selected from the group consisting of a nitrided layer, a galvanic layer, a thermal spray layer and a hard material layer separated in thin-layer technology, a run-in layer including an inner region applied to the wear layer and including WC, the thickness of the inner region of the run-in layer is 0.5 to 2 μm, the run-in layer including an outer region applied to the inner region and forming the outermost layer for sliding contact with a running face of a cylinder or cylinder liner, the outer region comprising a-C:H:W and at least one of nanocrystalline particles of WC and particles of cobalt, at least one of the inner region and the outer region comprising nanocrystalline carbide phases, and a metallic intermediate layer is provided between the inner region of the run-in layer and the wear layer.