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.