The elastic-plastic transition in nanoparticle collisions

MILLÁN, EMMANUEL N.; TRAMONTINA, DIEGO R.; URBASSEK, HERBERT M.; BRINGA, EDUARDO M.

PHYSICAL CHEMISTRY CHEMICAL PHYSICS

ROYAL SOC CHEMISTRY

Año: 2016 vol. 18 p. 3423 - 3429

1463-9076

When nanoparticles (NPs) collide with low velocities, they interact elastically in the sense that-besides their fusion caused by their mutual van-der-Waals attraction-no defects are generated. We investigate the minimum velocity, vc, necessary for generating defects and inducing plasticity in the NP. The determination of this elastic-plastic threshold is of prime importance for modeling the behavior of granular matter. Using the generic Lennard-Jones interaction potential, we find vc to increase strongly with decreasing radius. Current models do not agree with our simulations, but we provide a model based on dislocation emission in the contact zone that quantitatively describes the size dependence of the elastic-plastic transition.