Antiwear properties of carbon-coated copper nanoparticles used as an additive to a polyalphaolefin

This paper studies the influence of the addition of 25 nm carbon-coated copper nanoparticles on the tribological behavior of a polyalphaolefin (PAO6) and compares this behavior with the case of non-coated copper nanoparticles, determining the influence of coating. A block-on-ring tribometer, a four-ball machine, SEM and EDS were used in this research. The study concludes that the addition of carbon-coated copper nanoparticles decreases wear and increases the load-carrying capacity of PAO6. This tribological improvement is due to the deposition of nanoparticles on the rubbing surfaces and probably by their action as tiny bearings. The carbon-coated copper nanoparticles did not behave better than non-coated ones. (C) 2011 Elsevier Ltd. All rights reserved.