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

Abstract

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.