Orientation Dependence in Molecular Dynamics Simulations of Shocked Single Crystals

We use multimillion-atom molecular dynamics simulations to study shock wave propagation in fcc crystals. As shown recently, shock waves along the $〈100〉$ direction form intersecting stacking faults by slippage along $\{111\}$ close-packed planes at sufficiently high shock strengths. We find even more interesting behavior of shocks propagating in other low-index directions: for the $〈111〉$ case, an elastic precursor separates the shock front from the slipped (plastic) region. Shock waves along the $〈110〉$ direction generate a leading solitary wave train, followed (at sufficiently high shock speeds) by an elastic precursor, and then a region of complex plastic deformation.