Accurate Multiscale Simulation of Frictional Interfaces by Quantum Mechanics/Green's Function Molecular Dynamics

Area of Science:

• Computational materials science
• Tribology
• Surface chemistry

Background:

• Frictional phenomena are crucial for energy saving but difficult to study experimentally at buried interfaces.
• Current simulation methods struggle to capture the multiscale nature of friction.

Purpose of the Study:

• To develop and present a novel multiscale simulation approach for computational tribology.
• To enable realistic monitoring of interfacial chemistry and energy dissipation during sliding.

Main Methods:

• Linked ab initio and Green's function molecular dynamics.
• Simulation of tribochemical phenomena and energy dissipation due to bulk phonons under nonequilibrium conditions.
• Application to diamond surfaces with varying passivation.

Main Results:

• The method realistically describes interfacial chemistry and energy dissipation.
• Real-time monitoring of tribologically induced surface graphitization and passivation effects is achieved.
• Accurate estimation of friction coefficients for relevant material systems.

Conclusions:

• The developed multiscale approach advances the state-of-the-art in computational tribology.
• Enables in silico experiments for predicting and reducing friction in materials.
• Offers a powerful tool for understanding and engineering tribological interfaces.