Influence of thermo-mechanical properties of coatings on friction in elastohydrodynamic lubricated contacts

This paper presents a numerical investigation of the influence of thermo-mechanical properties of coatings on friction in elastohydrodynamic contacts. In a previous work by the author, it was shown that thermal properties of coatings had a significant influence on friction. In fact, under high sliding speeds, friction was found to increase with the thermal inertia of coatings. The current work reveals that mechanical properties of coatings also have a significant impact on friction. Friction actually exhibits an increase with the rigidity of the coating. Furthermore, a combination of soft coatings with low thermal inertia is shown to maximize friction reduction while hard coatings with high thermal inertia maximize friction increase. These effects are found to increase with the coating thickness.