Piston ring and process for producing same

• Main Authors: Ooshiro, Takehiko, Miyake, Koji, Chiba, Hidetoshi, Fujimagari, Eishi, Yoshida, Satoshi, Yamasaki, Takeyuki
• Format: Patent
• Language: English
• Published: 18.09.2018
• Subjects: BLASTING; CHEMICAL SURFACE TREATMENT; CHEMISTRY; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATIONOR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY IONIMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; COATING MATERIAL WITH METALLIC MATERIAL; COATING METALLIC MATERIAL; CYLINDERS; DIFFUSION TREATMENT OF METALLIC MATERIAL; ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVEFUNCTIONING OF MACHINES OR INSTALLATIONS; HEATING; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION INGENERAL; LIGHTING; MECHANICAL ENGINEERING; METALLURGY; PISTONS; SEALINGS; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THESURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; THERMAL INSULATION IN GENERAL; WEAPONS

Provided are a piston ring which, even when a sleeve constituted of an aluminum alloy is used, can sufficiently show the required low frictional properties, wear resistance, and low counterpart-material attacking properties, and a process for producing the piston ring. The piston ring has a rigid carbon film formed as the outermost layer thereof and serving as a sliding surface with a sleeve constituted of an aluminum alloy, wherein the rigid carbon film gives an X-ray diffraction pattern that has peaks assigned to graphite crystals. The rigid carbon film of the piston ring is formed using a chemical vapor deposition method. The rigid carbon film of the piston ring has a hydrogen content which is at least 20 atm % but lower than 30 atm %, and gives a Raman spectrum in which the ratio of the area (ID) of D-band peaks to the area (IG) of G-band peaks, ID/IG, is 0.5-2.0.