| 摘要 |
[Problem] To provide a piston ring having a hard carbon film that is easy to form and that has excellent wear resistance. [Solution] This problem is solved by having a hard carbon film 4 formed on at least the outer peripheral sliding surface 11 of a piston ring 1, wherein said hard carbon film 4 is a laminate film comprising multiple layers, and is configured so as to contain boron at an atomic density of 0.2×1022-2.0×1022 atoms/cm3. The hard carbon film 4 has an sp2 component ratio of 40-80%, measured in a TEM-EELS spectrum formed by combining electron energy loss spectroscopy (EELS) with a transmission electron microscope (TEM), and the hydrogen content can be configured to be 0.1-5 atom%. Further, the total thickness of the hard carbon film 4 can be configured to be 0.5-20μm. |
