Tribological Performance and Lubrication Mechanism of Carbon Microspheres as Oil-based Lubricant Additive on Aluminum Alloy Substrate

A one-step green hydrothermal method was used to prepare carbon microspheres with size of 400-500 nm by using glucose as the precursor compound. Morphologies and chemical properties of the carbon microspheres were characterized by means of SEM and FTIR. Their tribological properties as the lubricant additive were evaluated on aluminum-steel sliding contact by using a multi-functional friction and wear tester. The lubrication mechanism was also discussed. The results indicate that the carbon microspheres possess good friction-reducing and antiwear performance when they are used as the lubricant additive in both liquid paraffin and 0W-40 engine oil on aluminum-on-steel pairs. Carbon microspheres may enter the contact region and prevent the direct contact of the friction pair. At the same time, they may play a role as micro-nanospheres between the sliding contacts to provide an excellent lubricating effect.