Microstructure evolution from the atomic scale up

Abstract Microstructure evolution under external forces results from the complicate interplay of competing events originating at the atomic scale. The movement and interaction of, e.g., dislocations, grain boundaries, microcracks, occurs via many elementary atomic-scale events, which can be conveniently grouped into “geometric” and “topological”: the former can modify only the size and shape of the microstructure elements, while the latter may alter their number and connectivity (e.g. turning a bunch of dislocations into a grain boundary). We present and discuss the results of atomic-level simulations of both isolated and interacting defects. Then we describe a mesoscopic simulation framework based on a variational formulation of the dissipated work rate; such a model allows to correlate the elementary, atomic-scale events into a microstructure evolution model of great richness and complexity.