| 摘要 |
There is described a piston ring, particularly devised for use in internal combustion engines or compressors, comprising at least a metallic base (2) to which there is applied, by the process of physical vapor deposition (PVD), a coating (3) of chromium nitride that comprises a periodicity (P), formed by at least two adjacent layers (5,5'), each layer (5,5') having a predominantly chromium nitride phase different from the adjacent layer. |
