Tribochemical Interactions Between Lubricant Additives and Low Hydrogen Containing DLC Coating Under Boundary Lubrication Conditions

Diamond Like Carbon (DLC) coatings are becoming very popular for automotive tribo-components as they can offer excellent tribological properties resulting in improved fuel economy and reducing dependence on harmful components of existing additives. The tribochemical interactions of low hydrogen containing DLC coating with lubricants, basically customised for ferrous materials, are yet to be well understood. In this work, an experimental study has been performed to understand the synergistic and antagonistic effects of low friction and antiwear additives on a 15 at. % hydrogen containing DLC coating. Surface sensitive analytical techniques, such as atomic force microscopy (AFM) and X-ray photoelectron spectroscopy (XPS) were used to perform physical and chemical characterization of the tribofilms.