Modelling Friction Reduction Based on Molybdenum Disulphide Tribofilm Formation and Removal in Boundary Lubrication

Area of Science:

• Tribology
• Materials Science
• Nanotechnology

Background:

• Molybdenum dialkyldithiocarbamate is an effective friction modifier in boundary lubrication.
• Friction reduction relies on molybdenum disulfide (MoS2) nanosheet formation.
• Predicting MoS2 tribofilm buildup and friction remains challenging.

Purpose of the Study:

• Develop a Raman mapping methodology for quantitative MoS2 tribofilm analysis.
• Determine MoS2 tribofilm growth rates using experimental and numerical methods.
• Model friction reduction in boundary lubrication.

Main Methods:

• Developed a Raman map collection methodology for MoS2 quantification.
• Coupled tribochemical experimental data with numerical models.
• Implemented a numerical procedure for rubbing rough surfaces at various temperatures.

Main Results:

• Accurate quantitative analysis of MoS2 tribofilms was achieved.
• Localized MoS2 tribofilm buildup was observed.
• Predicted friction coefficients closely matched experimental measurements.

Conclusions:

• The developed Raman mapping and modeling approach accurately predicts MoS2 tribofilm growth and friction.
• The model is adaptable to different experimental conditions and surface geometries.
• This work advances the understanding and prediction of friction modification in lubrication.