MICRO-MECHANISMS OF ELASTO-PLASTIC CONTACT FOR CRYSTALS
晶体弹塑性接触的微观机制

Molecular dynamics(MD) and the embedded atom method(EAM) were used to simulate(FCC) Cu tip-to-substrate (a 3.4nm crystal slab) contact at 0.1K via NVT ensemble. Both the load-ing-unloading cycle and the potential energy of the system vs the tip approach were investigated. The atomistic stress fields in elastic contact were calculated by the lattice dynamics theory. On the other hand, for plastic indentation, we observed the plastic instability of the substrate when the tip approach was beyond some critical value. The voids initiation mechanisms were depicted through the atomic trajectories and con-figurations. The crystal defects after plastic indentation incIuded substrqte cavities, atomic steps and plastic indent.