Abstract
Molybdenum dialkyldithiocarbamate is a highly effective friction modifier lubricant additive in boundary lubrication, owing to the formation of a MoS(2) nanosheet lattice structure that significantly reduces friction. The friction reduction behaviour is linked to the MoS(2) amount and coverage buildup at the contacting interface, however, accurately predicting friction reduction based on a semi-deterministic model incorporating MoS(2) formation and removal remains challenging. In this study, a Raman map collection methodology was developed for accurate quantitative analysis of MoS(2) tribofilms. The growth rate of MoS(2) tribofilms was determined by coupling tribochemical experimental data with sophisticated numerical models. A full numerical procedure was implemented under rubbing of two rough surfaces at different temperatures. The results demonstrated localised MoS(2) tribofilms buildup. The friction coefficients show a close agreement with the measurements. The developed model can be adapted to diverse experimental setups and surface geometries. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s11249-025-01981-6.