Rubber friction on (apparently) smooth lubricated surfaces

TL;DR

This study reveals that seemingly smooth lubricated surfaces can have microscopic roughness that significantly influences rubber sliding friction through viscoelastic deformation, impacting rubber sealing and related applications.

Contribution

It demonstrates that microscopic roughness on smooth surfaces plays a key role in rubber friction, highlighting the importance of surface asperities in frictional behavior.

Findings

Microscopic roughness contributes to rubber friction.

Viscoelastic deformation dominates friction on smooth surfaces.

Implications for rubber sealing applications.

Abstract

We study rubber sliding friction on hard lubricated surfaces. We show that even if the hard surface appears smooth to the naked eye, it may exhibit short wavelength roughness, which may give the dominant contribution to rubber friction. That is, the observed sliding friction is mainly due to the viscoelastic deformations of the rubber by the substrate surface asperities. The presented results are of great importance for rubber sealing and other rubber applications involving (apparently) smooth surfaces.