Microscopic Mechanisms of Tribological and Wear Processes: Molecular Dynamics Simulations

Although tribological phenomena are an everyday experience and have been observed and studied for a very long time [1], a detailed microscopic theory of tribological phenomena is lacking. Nevertheless a large body of empirical data has been collected and some phenomenological models have been developed [2]. The major reasons, from a theorist’s perspective, for this state of affairs may be attributed to: (i) the complexity of the phenomena, which involve processes occurring in materials under stress, the generation and propagation of defects, large structural deformations and properties of systems beyond the elastic regime, (ii) the nature of available experimental data, which until fairly recently was not obtained under controlled conditions on compositionally and structurally well characterized samples. Recent advances in computer simulation methods [3] and the advent and application of surface science experimental probes provide the impetus for the development of fundamental models, on the atomic scale, of tribological and wear phenomena. In this note we outline our recent investigations in this area using molecular-dynamics (MD) simulations, and demonstrate the potential of such investigations towards the development of a microscopic understanding of the physical processes which underly these phenomena.