Atomistic modelling of shock load in nanophase aluminum nitride ceramics

Abstract

Large scale molecular-dynamics simulations of plane shock loading in nanophase aluminum nitride are performed to reveal the interplay between shockinduced compaction, structural phase transformation and plastic deformation. The shock profile is calculated for a wide range of particle velocity from 0.2 km/s to 4 km/s. The calculated Hugoniot curves agree well with the experimental one. For lower particle velocity, below 0.8 km/s a single elastic wave is generated. For intermediate particle velocity, between 0.8 km/s and 4 km/s the generated shock wave splits into an elastic precursor and a wurtzite-to-rocksalt structural transformation wave. For particle velocities greater than 4 km/s a single overdriven transformation shock wave is generated above the longitudinal sound speed. These simulation results provide a microscopic view of the dynamic effects of shock impact on single crystal and nanophase high-strength ceramics.