Mechanism and regulation of oil-lubricated triboelectrification at steel/PTFE interface

Electrostatic accumulation at the oil-lubricated interface may cause electrostatic adsorption of impurities and oil aging. However, there are still great challenges in the triboelectric mechanism and electrostatic regulation under oil lubrication state. Under PAO4 lubrication, the electrostatic accumulation at the interface is serious (-1873 V), which can be attributed to the inhibition effect of lubricating oil on transfer film and electrostatic breakdown in interfacial air. When Span 60 was added to the PAO oil, the surface potential of PTFE was significantly reduced because the adsorption of Span 60 inhibited the electron transfer at the interface. This study reveals the triboelectric mechanism under oil lubrication from the tribological perspective and offers new strategies for electrostatic protection of oil-lubricating interfaces.