Synergetic lubrication between MoDTC and TiO₂ nano-additive: Dynamic evolution of tribofilm induced by tribocatalysis and tribomechanical effect

Molybdenum dithiocarbamate (MoDTC) can significantly reduce friction and wear through the formation of lubricious tribofilm by decomposition of MoDTC, but it is difficult to regulate the tribochemical behaviors. In this study, TiO₂ nanoparticles are used as nano-additive combined with MoDTC, leading to reduced friction and wear under 50 N. The addition of TiO₂ with proper concentration can promote the formation of lubricious Mo-content tribofilm. Meanwhile, TiO₂ in tribofilm can also lead to enhanced wear-resistance. Moreover, the dynamic evolution of the tribofilm is also investigated under varied conditions to elucidate the synergetic lubrication mechanisms between MoDTC and TiO₂. These findings offer fundamental insights of the lubrication mechanisms of MoDTC when combined with nano-additives from both tribochemical and tribomechanical viewpoints.