Effect of copper oxide@boron nitride nanosheet hybrid nanocomposite on tribological properties of paraffin liquid

Abstract Due to the significant friction-reduction and anti-wear properties of nano particle, nano copper oxide (CuO) particle decorating on boron nitride nanosheets (BNNS) nanocomposites are fabricated with polydopamine (PDA) as the linking agent. The structural and morphological characteristics of the CuO@BNNS composite are characterized by scanning electron microscopy (SEM), X-ray diffraction patterns, fourier transform infrared spectroscopy and thermogravimetric analysis. The synergistic effect of CuO and BNNS on extreme pressure of lubrication oil are investigated. A four-ball tribometer is adopted to investigate the tribological behaviors of the as-prepared oil with different additives. Optical microscope and SEM are used to analyze the topography of worn surface. Energy dispersive spectroscopy is adopted to investigate the element distribution on worn surface. The results demonstrate that the CuO@BNNS nanoparticle could effectively improve the friction-reduction and anti-wear properties of the paraffin liquid, compared to paraffin liquid containing modified CuO (f-CuO) or PDA-BNNS respectively. The worn surface of steel ball presents smooth morphology for oil containing CuO@BNNS, contrast to oil containing f-CuO or PDA-BNNS respectively. With the tribo-film formation on the worn surface, the elements distribute uniformly on the worn surface for oil containing CuO@BNNS. Compared to lower load, the effect of load-carrying capacity and easy-shear property of CuO@BNNS outstand under 392 N, which results in the smooth worn surface compared to oil containing other additives. Article Highlights CuO@BNNS hybrid nanoparticle was prepared with a simple and mild method. CuO@BNNS presents superior anti-friction and anti-wear properties due to the synergistic effect of nanoparticle. The result obtained in the paper promotes the application of h-BN based nanocomposites in tribology.