Study on the Tribological Mechanism of Ultrafine SiO2/MoS2 Powders in Complex Calcium Sulfonate Grease

The purpose of this work was to study and further clarify the anti-wear and anti-friction mechanism of ultrafine SiO2/MoS2 powders in the complex calcium sulfonate grease. In this paper, 15nm nanoSiO2, 1μm MoS2 and commercial NLGI Grade No.2 complex calcium sulfonate grease were used as the research objects, SEM, EDS and XPS were used to study the morphology, composition and film chemical constitution of the long friction wear spots of grease containing single nanoSiO2 powder, ultrafine MoS2 powder and the two compound powders, which formed in the process of four ball long friction. The results show that nanoSiO the grease plays a role in filling the undercut, ball bearings and polishing and forming high hardness Ca3Fe2(SiO4)3 and part of Fe2O3 anti-wear films in the process of long friction. The ultrafine MoS2 powder has a self-repairing effect to fill the grooves,forming the MoS2, MoO3 anti-friction films and Fe2(SO4)3 anti-wear film. The two powders in the composite grease have a synergistic effect, acting on the friction pair together, and simultaneously forming self-repairing anti-friction and anti-wear films, thereby further improving the tribological performance of the base grease.