Shock-induced consolidation of tungsten nanoparticles - A molecular dynamics approach

Shock-induced consolidation of tungsten nanoparticles to form a bulk material was modeled using molecular dynamics simulation. By arranging the nanoparticles in a three-dimensional model of body-centered cubic super-lattice, the calculated shock velocity-particle velocity Hugoniot data are in good agreement with the experiments. Three states, including solid-undensified, solid-densified, and liquid-densified, can be sequentially obtained with the increase of the impact velocity. It is due to the flow deformation at the particle surface that densifies the cavity, and the high pressure and temperature that join the particles together. Melting is not a necessary factor for shock consolidation. Based on whether or not melting takes place, the consolidation mechanisms are liquid-diffusion welding or solid-pressure welding.