Lubricities of Super Fine SiO2 Particle as a Solid Lubricant

The effect of the anti-galling and wear resistance of super fine SiO2 particles (7-40nm in mean diameter) were investigated by using a Falex (pin/vee block) friction testing machine, when they were added into lithium soap-lubricating grease as solid lubricants. The SiO2-added greases showed higher seizure loads and less wear amounts as compared with no-added grease. Especially, the addition of the finest 7nm-SiO2 particles with the oleophilic surface treatment showed the highest seizure load. The lubricating actions of these super fine SiO2 particles are due to their existences at the friction interface which decrease the metallic contact between frictional surfaces, thus result in high seizure loads and antiwear properties.