Influence of grain boundary properties on spall strength: Grain boundary energy and excess volume

Several factors can affect the spall strength of a grain boundary, such as grain boundary structure, energy, and excess volume (EV), in addition to its interactions with dislocations. In this paper, we focus on the influence of grain boundary energy and excess volume on the spall strength of a grain boundary, in copper from molecular-dynamics simulations. Flyer plate simulations were carried out for five boundary types with different energies and excess volumes. These boundaries were chosen as model systems to represent various boundaries observed in “real” materials. Simulations indicate that there is no direct correlation between the spall strength of a boundary and either its energy and excess volume. This result suggests that average properties of grain boundaries alone are not sufficient indicators of the spall strength of a boundary and perhaps local boundary properties need to be taken into account in order to predict its spall strength for broad ranges of materials.