Current‐Carrying Tribological Behavior of NbN Coating under Oil Lubrication

In recent years, NbN has garnered significant attention in research due to its exceptional superconductivity, wear resistance, and corrosion resistance. In this study, a magnetron sputtering method is used to create a high‐hardness NbN coating onto a steel substrate. In the presence of polyalphaolefin 6 as a lubricant, the tribological behavior of the NbN coating is examined in both electrified and nonelectrified situations. The results indicate that the bare steel substrate experiences a larger wear rate of 4.03 × 10 −4 mm 3 Nm −1 , whereas the NbN‐coated sample exhibits a wear rate as low as 1.23 × 10 −5 mm 3 Nm −1 , representing a 97.5% reduction as compared to the uncoated substrate. It is observed that the current accelerates the oxidation reaction upon the NbN coating's surface, positively influences its wear resistance, and causes a lubricating film made mainly of Nb 2 O 5 to form on the wear track. Consequently, even under current‐carrying conditions, the NbN coating demonstrates superior wear resistance and electrical damage resistance.