Waviness affects friction and abrasive wear

TL;DR

This study reveals that detailed surface waviness significantly impacts friction and abrasive wear, with small deviations causing notable increases in friction and uneven wear patterns.

Contribution

It introduces the use of complete waviness profiles to understand their influence on abrasive wear, moving beyond simple scalar roughness measures.

Findings

Small surface deviations can increase friction coefficient by up to 91%.

Frictional fluctuations are strongly correlated with initial waviness profiles.

Uneven wear correlates with surface waviness and fluctuations.

Abstract

To prolong lifetime and reduce energy consumption, a thorough understanding of abrasive wear is essential. The potentially crucial influence of surface topography intricacies on tribological behavior have been obscured, since roughness and waviness are often considered simple scalar quantities. Here, the complete waviness profile of the sliding track was used to shed light on the influence of surface topography on abrasive wear. Bearing steel pins and disks were tribologically tested with Al2O3-based slurries as interfacial medium. It was found that even small surface deviations (albeit minimized and controlled for) can significantly increase the friction coefficient - up to 91 %. Not only are frictional fluctuations strongly correlated with the disks' initial waviness profile, these small fluctuations correlate with unevenly-distributed high wear.