Piston ring and a method of producing the same

摘要

A base body of a piston ring has an electroplated chrome or gas nitrided sub-layer formed on its outer peripheral face. The sub-layer is face-lapped, roughened through grit blasting, and then oil lapped to remove the asperities. The resulting plateau-reservoir surface has a smooth plateau and a number of reservoirs. A metallic nitride face coating is applied to the sub-layer. The reservoirs provide additional surface area to promote the bonding between the metallic nitride and the sub-layer. The coating does not eliminate the reservoirs, however. Thus, the reservoirs provide the additional function of storing lubricating oil which may be used during piston ring operation to eliminated unwanted wear.