High strain-rate loading of nanofoams*

Nanoscale metallic foams display mechanical properties which make them attractive for a variety of technological applications. We report simulated high strain-rate loading for a model polycrystalline nanoporous gold structure with around 10 nm mean filament diameter and 15 nm average grain size, comparable to foams produced by dealloying.

Plasticity occurs predominantly at the nodes and is dominated by nucleation of dislocations at the atomic steps of the ligament surfaces, Shockley partials, full dislocations, Hirth partials, Lomer-Cottrel locks and twins were identified. Grain boundary sliding appears to play a minor role in deformation. Several scaling laws are tested and their results and applicability are discussed based on the structural parameters of the foam.