20.500.12556/RUL-175994 Superlubricity of diamond-like carbon coating lubricated with aqueous glycerol under electrified sliding conditions Hydrogenated diamond-like carbon (H-DLC) coatings are promising materials for minimizing electrical degradation under electrified sliding systems. However, its safe operational voltage threshold required to avoid dielectric breakdown, electrical arcing, and lubrication failure, especially under aqueous lubrication, remains largely unknown. This study explores the sliding performance of steel/H-DLC contact pair lubricated with aqueous glycerol under electrified sliding conditions. The results demonstrate that at applied voltage below 1 V, a stable macroscale superlubricity was observed with a coefficient of friction (COF) ranging between 0.007 and 0.009. The COF increased by 37.5 % when the applied voltage increased to 1.2 V, while a further increase to 1.4 V caused coating degradation, indicating a voltage-induced loss of superlubricity. Analysis revealed that the H-DLC coating retained its structural integrity without graphitization under ≤ 1 V, and the achieved superlubricity was due to the surface passivation by the hydroxyl-terminated groups that form a low shear interface. However, as the applied voltage exceeds the 1 V threshold, sp$^3$-to-sp$^2$ structural transformation occurs, suggesting an electric-field-induced graphitization mechanism that leads to the dielectric breakdown and lubrication failure. These findings provide crucial insights into the electrified sliding performance of H-DLC coatings, rendering them one of the promising candidates for electro-mechanical systems. superlubricity hydrogenated diamond-like carbon electro-tribology aqueous glycerol electrified interfaces graphitization supermazljivost hidrogeniran diamantu podoben ogljik elektrotribologija vodni glicerol elektrificirani vmesniki grafitizacija true false true Angleški jezik Slovenski jezik Članek v reviji 2025-11-17 14:51:31 2025-11-17 14:51:38 2026-07-13 13:32:58 0000-00-00 00:00:00 2026 0 0 14 str. pt. A, art. 111415 Vol. 215 2026 0000-00-00 Zaloznikova Objavljeno NiDoloceno 0000-00-00 0000-00-00 0000-00-00 539.92 1879-2464 10.1016/j.triboint.2025.111415 257496579 1-s2.0-S0301679X25009107-main.pdf 1-s2.0-S0301679X25009107-main.pdf 1 D09675C1F17F7A68B28276E71378B945 01684c16ff72c72bf24860b5eb12ad004930dbeb64bf238165538b8531064fdb ee3a4cff-79ec-11f1-9b0d-0050569b8976 https://repozitorij.uni-lj.si/Dokument.php?lang=slv&id=237252 https://www.sciencedirect.com/science/article/pii/S0301679X25009107 0 32e7686b-c3bc-11f0-9328-0050569b8976 https://repozitorij.uni-lj.si/Dokument.php?lang=slv&id=222009 Fakulteta za strojništvo 0 0 0