Nanoscale Plastic Wear of α-Quartz Asperities During Shear Sliding: Insights From Molecular Dynamics Simulations

Abstract

Fault slip inevitably causes the multiscale wear damage of asperities, ranging from nanometers to meters. However, the nanoscale asperity wear mechanism remains poorly understood. While plastic wear has been inferred as one of the dominant wear modes, the dynamic wear mechanism of plastic wear has not been thoroughly investigated. Here, we explicitly present a series of nanoscale 3-D plastic wear processes of α-quartz asperities by using molecular dynamics method, where asperity climbing mode dominates during the sliding. We identify a transition from atom-by-atom wear damage to layer removal of α-quartz asperities with increasing normal forces. Moreover, nanoscale wear volume evolution depends on the normal force and loading velocity and shows sublinear increase with loading distance. We confirm that the tangential shear work can well predict the nanoscale plastic wear volume under various loading conditions due to the proportional relation.