Chemical aging of large-scale randomly rough frictional contacts

Abstract

It has been shown that contact aging due to chemical reactions in single asperity contacts can have a significant effect on friction. However, it is currently unknown how chemically-induced contact aging of friction depends on roughness that is typically encountered in macroscopic rough contacts. Here, we develop an approach that brings together a kinetic Monte Carlo model of chemical aging with a contact mechanics model of rough surfaces based on the boundary element method to determine the magnitude of chemical aging in silica/silica contacts with random roughness. Our multi-scale model predicts that chemical aging for randomly rough contacts has a logarithmic dependence on time. It also shows that friction aging switches from a linear to a non-linear dependence on the applied load as the load increase. We discover that surface roughness affects the aging behavior primarily by modifying the real contact area and the local contact pressure, whereas the effect of contact morphology is relatively small. Our results demonstrate how understanding of chemical aging can be translated from studies of single asperity contacts to macroscopic rough contacts.

arXiv comment19 pages, 6 figures, 1 table

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Cited by in corpus (7)

• Physical Origin of the Mechanochemical Coupling at Interfaces
• Stochastic Properties of Static Friction
• Load-velocity-temperature relationship in frictional response of microscopic contacts
• Adhesive wear mechanisms in the presence of weak interfaces: Insights from an amorphous model system
• The Decrease of Static Friction Coefficient with Interface Growth from Single to Multiasperity Contact
• A Linear Time-Variant Rheological Model for Frictional Aging, Stress Relaxation, and Creep
• Evolution of the contact between rough viscoelastic solids after decreasing loads: memory erasure and monotonic increase