Performance of diamond-like carbon coatings (produced by the innovative Ne-HiPIMS technology) under different lubrication regimes

• Published in: Wear Vol. 477; p. 203775
• Main Authors: Cardoso, Fábio, Ferreira, Fábio, Cavaleiro, Albano, Ramalho, Amílcar
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 18-07-2021; Elsevier Science Ltd
• Subjects: Argon; Chromium nitride; Coatings; Diamond films; Diamond-like carbon; Diamond-like carbon films; Friction; HiPIMS; Internal combustion engines; Lubrication; Magnetron sputtering; Microscopes; Neon; Optical microscopes; Piston rings; Stribeck curves; Tribology; Wear resistance; Stribeck curves; Neon; Diamond-like carbon; HiPIMS; Piston rings; Tribology
• ISSN: 0043-1648; 1873-2577
• DOI: 10.1016/j.wear.2021.203775

Piston rings (PR) are responsible for over 24% of the friction losses in internal combustion engines. To minimize the friction losses and improve the life span of PR it was tested a new developed variation of the diamond like carbon (DLC), in this case, deposited on a plasma atmosphere of Argon and Neon with high power impulse magnetron sputtering (HiPIMS) power supply at P = 0,8 Pa and with a bias of −80 V. These coatings were compared with the widely used Chromium nitride (CrN) and DLCs deposited in pure Argon atmosphere. The tribology tests were performed on a block-on-ring setup with counter-body, loads, velocities and lubrication that represented the real conditions of the PR. The analyses of the results were performed using the stribeck curves where it was observed an improvement of 15.7% in friction losses of the DLC deposited with 25% of Ne in the discharge gas when compared with CrNs at the mixed lubricated regime. As well as an improvement on wear resistance on boundary regime. The wear tests were analyzed with profilometry and wear track optical microscope images.
•Diamond-like carbon films were deposited by HiPIMS in Ne discharge.•Tribology tests were performed under different lubrication regimes.•Improvement of 15.7% in friction losses on the DLC 25% Ne coating.•Low wear rate observed for DLC 25% Ne coatings.