Mechanochemistry mechanism of lubrication recovery and wear maps of base oil

Lubrication recovery has been observed in tribology research. It meant the recovery of oil lubrication on metal after a failure or semi-failure by waiting a period. Past studies attributed this recovery to metal oxidation. However, this paper presented an alternative mechanism. We proposed that the accumulation of carbon-containing tribofilm from hydrocarbon oils was crucial for lubrication recovery. Changes in surface states, such as enlarging contact areas, also played a significant role. For studying wear mechanism maps, it should be essential to consider both working conditions and surface states. Two new wear mechanism maps based on initial surfaces with or without pre-generated tribofilm were developed. These findings highlight the mechanochemical effects of base oils on lubrication and antiwear performance.