Tribological properties and mechanism of Cu nanoparticles

The tribological properties of Cu nanoparticles as lubricating oil additive were evaluated on a facing tester. The morphology, element distribution and micro mechanical property of the worn surface were investigated by means of scanning electron microscopy (SEM), energy dispersive spectrometry (EDS) and nanoindentation tester. The results show that the wear resistance and friction reduction properties of 650SN mineral oil are improved markedly by adding Cu nanoparticles. The friction surface temperature lubricated by nanocopper additive is clearly lower than that lubricated by 650SN. A protective copper film is generated on the rubbed surface, which has lower hardness than 45^# steel and contributes to better tribological properties.