Inelastic flow processes in nanometre volumes of solids

The authors consider the types of inelastic process that may occur in very small volumes of material, using the model system of a sharp tip coming into contact with a flat. Both molecular dynamics simulations and experimental results are presented. Theoretical lattice strength is observed, adhesion between clean surfaces is strong and involves inelastic flow, and the adhesion is considerably reduced by differing atomic species at the interface. The MD simulations, using long-range potentials, show that the processes likely to be occurring include local sintering or diffusion-like flow, enhanced by local soft modes, and net material transfer upon adhesive unloading.