Effect of wear particles and roughness on nanoscale friction

Frictional contacts lead to the formation of a surface layer called third body, consisting wear particles and structures resulting from their agglomerates. Its behavior properties at nanoscale control macroscopic tribological performance. It is known that topography evolve with time mutually influence one another. However, mature body largely uncharted territory its early stages are unknown. Here we show how initially acting as roller bearings transitions into shear-band-like state by forming adhesive bridges between particles. Using large-scale atomistic simulations on brittle model material, find this transition controlled growth increasing disorganization sliding distance. Sliding resistance rate first roughness, but upon agglomeration stagnates friction becomes solely dependent real contact area in accordance plasticity theory Bowden Tabor.