Molecular dynamics simulation of interfaces and microstructure evolution during high-speed sliding

Three-dimensional nonequilibrium molecular dynamics simulations are performed to investigate the tribological characteristics of the high-speed sliding system. A sliding simulation model with two blocks is built. The friction force, the evolution of the structure of interface and the temperature profiles of the sliding system are obtained. The relationship among tribological characteristic, friction heat, and interface structure is studied. The influence of the sliding velocity is investigated. The velocity field of the interface is also considered. The theoretical analysis of the mixing layer is also built to study the flow and heat transfer characteristics in the interface. The results show that structure of the interface can greatly affect the friction force and temperature rising. The structure factors and the velocity field of the interface evidently suggest that atomic flow during sliding is similar to fluid flow, which is beneficial to reduce the friction force and heat dissipation. With the increase of sliding velocity, the thickness of the mixing layer increases, the steady state friction force decreases. The atom distribution and the radial distribution function of the interface indicate that the degree of short-range disorder of the mixing layer increases.