Gas-liquid detonation synthesis of graphite coated copper nanoparticles and tribological performance as lubricant additives

Abstract

ABSTRACTGraphite coated copper (Cu@G) nanoparticles were successfully prepared by a gas-liquid detonation method, using copper acetate, ethanol, hydrogen and oxygen as the detonation precursors. The composition, morphology and microstructure of detonation products were analyzed by X-ray diffraction (XRD) and transmission electron microscopy-energy dispersive X-ray spectrometry (TEM-EDX). And a four-ball wear test was carried out to clarify the tribological properties of the mixed lubricating oils, which mainly consisted of the SN150 base oils containing five different concentrations of Cu@G nanoparticles. The results indicated that Cu@G nanoparticles are made up of face-centered cubic (FCC) copper nanocrystal and graphitic shells. The size distribution of core-shell structural products is mainly in range of 10–40 nm and the graphitic shells is about 4–8 nm. From the four-ball tests, the friction coefficient and wear scar diameter (WSD) decrease firstly and then increase with the increase of the contents of Cu@G nanoparticles. When the content of Cu@G nanoparticles is 0.6%, there is a minimum friction coefficient and WSD.