Preparation and tribological behavior of a self-assemble copper base carbon quantum dot films

A copper-based carbon quantum dots (Cu-CQDs) and its films on the surface of steel discs were prepared successfully by the hydrothermal method and simply immersion into Cu-CQDs solution method, respectively, in order to develop a functional additive and high performance of bearing materials. Thus obtained Cu-CQDs has an average particle size of approximately 10 nm. The physical and chemical properties of the prepared Cu-CQDs and its films were studied using various modern instruments like SEM, RAMAN, XRD, etc. An UMT-2 tribometer was conducted to investigate the tribological behavior of lubricated thin films. Here, the films played an important role in modifying of friction and wear properties of bearing steel discs. The lower friction coefficient and wear rate of film-coated steel discs were achieved lubricated with 0.5 wt% Cu-CQDs. The tribological mechanisms of Cu-CQDs and films were ascribed to the formation of lubrication films including the components of Cu-CQDs and the friction-induced formation of transfer film, respectively.