Friction in the zero sliding velocity limit.

Area of Science:

• Physics
• Materials Science
• Tribology

Background:

• Dry friction is a ubiquitous phenomenon observed at the interface of sliding surfaces.
• Understanding the fundamental mechanisms of friction, especially at the molecular level, remains a significant challenge.
• Existing models often struggle to explain the universal occurrence of dry friction and the relationship between static and kinetic friction.

Purpose of the Study:

• To develop a theoretical model that explains the universal occurrence of dry friction at zero temperature.
• To extend the model to calculate kinetic friction at nonzero temperatures.
• To investigate and account for the phenomenon of static friction being larger than kinetic friction.

Main Methods:

• Utilized an adiabatic approximation method to identify Tomlinson model-like instabilities.
• Developed a realistic model for two crystalline surfaces with mobile molecules at the interface.
• Modified the adiabatic approximation method to incorporate nonzero temperature effects.

Main Results:

• The model successfully accounts for the widespread observation of dry friction at zero temperature.
• The modified method enables the calculation of kinetic friction at nonzero temperatures.
• Demonstrated that the model can explain static friction being greater than kinetic friction.

Conclusions:

• The proposed theoretical framework provides a robust explanation for dry friction in crystalline materials.
• The model offers a unified approach to understanding friction across different temperature regimes.
• The findings contribute to a deeper understanding of tribological phenomena at the nanoscale.