Atomistic simulations of shock induced microstructural evolution and spallation in single crystal nickel

Spallation in single crystalline nickel was studied using molecular dynamics simulations. The shock waves-incident waves, the waves reflected from sample free surfaces, and interference between reflected waves-create and destroy many microstructural features. These features, though unimportant in determining the spall strength, control the spall nucleation site. Spall occurs by cavitation at a grain boundary junction in cold, defective, tensile regions of the sample. Atomistic calculations and experiments, though separated by six orders of magnitude in strain rates, follow a universal strain rate behavior.