Booster effect of fatty amine on friction reduction performance of Mo-based additives

This paper investigates the boosting effect on friction reduction performance of a fatty triamine (AM) when used as a third organic additive to base oil containing molybdenum-based additives and ZDDP for different tribopairs. The addition of the AM gives an unreached friction level under boundary lubrication with organic molybdate and ZDDP for steel. The structure of the tribofilm obtained with ternary mixture composed of stoichiometric MoS2 long sheets located on top surface and aligned in the sliding direction could be at the origin of this remarkable behavior. Finally, a tribochemical action mechanism is proposed to describe the functionality of AM in boosting the formation of long MoS2 lamellar sheets.