ZDDP and MoDTC interactions and their effect on tribological performance - tribofilm characteristics and its evolution

In this work, the interactions between two key additives in current lubricants (ZDDP and MoDTC) and the effect on tribofilm formation and tribofilm evolution under boundary lubrication are studied. The chemical and tribological characteristics of the tribofilms are probed using measurement of friction, wear and film characteristics. Tribofilms have been examined by energy dispersive X-ray analysis (EDX) and X-ray photoelectron spectroscopy (XPS). In order to investigate the morphology of the reaction films formed, atomic force microscopy (AFM) was used. In this work, for the first time, a link between a proposed MoDTC breakdown mechanism and MoDTC tribofilm characteristics, measured on experimentally derived tribofilms, is made.