EFFECT OF ECO-FRIENDLY CARBON MICROSPHERES ON THE TRIBOLOGICAL BEHAVIOR OF LITHIUM LUBRICATING GREASE

Eco-friendly carbon spheres (CS) used for lithium grease were synthesized by hydrothermal synthesis in this work. The obtained composite greases were evaluated on a HSR-2M ball-on-disk friction machine to explore the frictional and wear behaviors under different additive contents and loads. The morphology of worn surface is analyzed by scanning electron microscope (SEM) and three-dimensional surface profiler. Results showed that when the content of CS in grease is 1wt% at the load of 60N, the friction coefficient (COF) is reduced by more than 20% compared with that of base grease. The worn surface is quite smooth with few shadow furrows and the wear volume decrease by more than 40% compare with base grease when the content of CS is 1wt%. The results indicated that CS displayed excellent anti-wear ability and friction reducing performance as lubricating grease additive. The lubricating mechanisms of CS were the 'micro-roller 'effects, repairing and forming the protective film.