SLIDING ELEMENT, IN PARTICULAR A PISTON RING, HAVING A COATING

摘要

The invention relates to a sliding element, such as a piston ring, comprising a coating on at least one surface comprising, form inside to outside, a bonding layer, a metal DLC layer preferably containing tungsten, and a metal-free DLC layer doped with nitrogen at least in some regions, wherein said sliding element is characterized in that the nitrogen content in the metal-free DLC layer is graduated.