The tribological performance evaluation of steel-steel contact surface lubricated by polyalphaolefins containing surfactant-modified hybrid MoS2/h-BN nano-additives

This study mainly investigated and compared the tribological behavior of steel/steel surface lubricated by poly alpha olefin (PAO 6) oil containing MoS2/h-BN hybrid nanoparticles with and without oleic acid (OA) modification at different concentrations and loads via a four-ball tribometer. The physicochemical properties of nanofluids were respectively investigated by rheological and thermogravimetric analyses. In addition, the microcosmic morphology analysis of the worn surface was elaborately analyzed via field-emission scanning electron microscopes (FE-SEM), energy dispersive spectrometer (EDS), mapping element analysis, three dimensional (3D) optical profilometer, and X-ray photoelectron spectroscopy (XPS). The study revealed that excellent tribological properties were found employing hybrid nano lubricants (NL) due to the formation of the tribo-film on the surface of the tribo-pair. Finally, the tribological lubrication mechanism was suitably proposed. •The tribological characteristics of MoS2/h-BN nanolubricant were detected via a four-ball tribometer.•The thermal stability of hybrid nanolubricant is better than that of PAO 6 oil via TGA and DTA analyses.•The COF and WSD values were greatly reduced by approximately 37% and 42.3%, respectively.•The formation of tribo-film is responsible for the primary lubrication mechanism.