Molecular-dynamic simulation of shock-wave compacting of aluminum nanopowder

A molecular-dynamic modeling of the compacting of a monodisperse aluminum nanopowder with a diameter of nanoparticles of 6–24 nm under the impact of shock compression pulses with an amplitude of 1 to 15 GPa and a duration of 30 to 100 ps was carried out. A layer of nanopowder 120 nm thick was placed between two aluminum walls with a thickness of 122 nm each, the walls simulated the container. A pressure pulse was applied to the outer surface of one of the walls. Depending on the amplitude of the shock compression pulse, either elastic compression of nanoparticles or their plastic deformation leading to compaction was observed. At large pulse amplitudes, the resulting rarefaction wave leads to a splitting in the thickness of the compact. The amplitude of 5 GPa is sufficient for complete compaction of nanoparticles.