Superlubricity and Near-Wearless Sliding in Carbon Films

Systematic studies on carbon-based materials and coatings in our laboratory over the past 15 years have led to the discovery of an amorphous carbon film that can provide friction coefficients as low as 0.001 and wear rates of less than 10⁻¹⁰ mm³/N.m when tested in inert or vacuum test environments. This paper provides an overview of the recent progress made in the synthesis and characterization of such films and of the importance of near-surface chemistry and chemical interactions on friction and wear. Based on extensive surface analytical and tribological studies, a mechanistic model is proposed to explain the superlubricity and near-wearless sliding behavior of these carbon films.