Influences of added sand-dust particles on the tribological performance of graphite-like coating under solid–liquid lubrication

Graphite-like carbon (GLC) coatings were fabricated by unbalanced magnetron sputtering technique. Raman spectroscopy and XPS analysis confirmed the nanostructured GLC coatings have high concentration of sp2-hybridized carbon. HRTEM analysis demonstrated that the microstructure of GLC coatings was composed of nanocrystalline graphite, fcc-center cubic (fcc) diamond and amorphous carbon. The tribological performance of GLC coatings combined with five types of liquid lubricants (PFPE, PAO, SO, IL and MAC) has been investigated under the conditions without and with sand-dust particles. Experimental results showed that the obtained excellent low friction and wear-resistance was attributed to the synergistic effect of liquid lubricants and GLC coatings.