A study on the tribofilm growth and tribological properties of tribofilms formed from zinc dialkyl dithiophosphate (ZDDP) and molybdenum dialkyl dithiocarbamate (MoDTC)

Abstract

Tribofilms are critical for the management of wear and the control of friction. This study focused on the tribological properties of tribofilms to clarify their antiwear and low-friction mechanisms. By monitoring tribofilm growth and measuring friction-coefficient mapping, we found that a tribofilm was generated in a dynamic process of formation and wear. The friction coefficient decreased with an increase in film thickness. The friction coefficient distributions of the tribofilms depended on the chemical nature more than the surface morphology. ZDDP formed a tribofilm with good antiwear properties, whereas MoDTC accelerated the tribofilm formation and decreased the friction coefficient.