Improving the tribological properties of diamond-like carbon film applied under methane by tailoring sliding interface

Abstract

Methane fuel will be valued as a renewable and alternative energy source in the new future. Nevertheless, during transportation and application of methane, the damage to moving mechanical components results in a huge loss to the society. Diamond-like carbon (DLC) film, with lots of excellent frictional performances, is expected to resolve the above issue. Herein, experiments were performed by tailoring sliding interfaces under methane to explore the tribological mechanism of DLC film under methane atmosphere. It was found that initial tribological interface had an important impact on the frictional performances of DLC film. Raman spectra demonstrated that the reconstruction, which was critical for the tribological performances of DLC film under methane, occurred at the sliding interface with shearing. The first principles calculation result revealed that carbon dangling bonds were passivated with the groups dissociated from methane. Combining with the hardness of wear tracks, an appropriate passivation on the sliding interface and suitable rigidity of the system were found to be great for the low friction of DLC film under methane atmosphere. The results indicate that DLC film exhibits outstanding lubricating and wear-resistant properties under methane by tailoring sliding interface.