| 摘要 |
Provided are a piston ring and a seal ring for a turbo charger that are provided with a hard covering film having low aggression to mating materials and superior cracking and peeling resistance. The piston ring and the seal ring for a turbocharger are such that the hard covering film covers at least one surface selected from the outer peripheral surface, a first lateral surface, and a second lateral surface of a substrate, the hard covering film has an NaCl-type crystal structure and has a composition containing Ti, Al, N, and C, where the atom ratio (Al/(Ti+Al)) is in the range of 0.10-0.63 and the atom ratio (C/(N+C)) is in the range of 0.02-0.40, the void area ratio in a cross section of the hard covering film is no greater than 2.2%, and the ratio (I200/I111) of the diffraction peak strength in the (200) plane with respect to the diffraction peak strength in the (111) plane in an X-ray diffraction measurement of the hard covering film exceeds 1 and is no greater than 15. |
