Advanced Tribological Characterization of DLC Coatings Produced by Ne-HiPIMS for the Application on the Piston Rings of Internal Combustion Engines

Piston rings (PR) are known for almost a quarter of the friction losses in internal combustion engines. This research work aims to improve tribological performance PR by recently developed variant Diamond-like Carbon (DLC) coatings deposited mixture Ar and Ne plasma atmosphere (Ne-DLC) high-power impulse magnetron sputtering (HiPIMS). For benchmark, widely used Chromium Nitride (CrN) DLCs pure (Ar-DLC) were used. The tests performed on block-on-ring configuration under different lubrication regimes varying temperatures sliding speeds. analysis results was Stribeck curves corresponding each sample. An improvement observed Ne-DLC films up 22.8% reduction COF compared CrN boundary regime, whereas, Ar-DLC film, this only 9.5%. Moreover, achieved ultralow less than 0.001 during transition hydrodynamic regime due better wettability (lower contact angle) higher surface free energy. Increasing 50% discharge gas also leads an increase hardness DLC from 19 24 GPa.