Electro-tribological properties of diamond like carbon coatings

Diamond like carbon (DLC) coatings typically present good self-lubricating tribological properties that could be of interest in sliding dielectric contacts in multiple electrical applications. In this work electro-tribological studies have been performed on several DLC coatings against aluminum in different humidity conditions, in which the coefficients of friction (CoFs) and electrical contact resistance (ECR) were continuously monitored. Results show that CoF and ECR data can be linked to the properties of the coatings (thickness, finishing, microstructure, residual stresses, and wettability) and the degradation modes of their tribological and electrical properties. Therefore, electro-tribological data can provide valuable information about the performance of dielectric coatings, the reasons behind it, and assist in the development of the coatings. ECR also shows potential for on-line monitoring of coated parts in operation.