Abstract and subjects
Several factors can affect the failure stress of a grain boundary, such as grain boundary structure, energy and excess volume, in addition to its interactions with dislocations. In this paper, we focus on the influence of grain boundary energy and excess volume at the boundary on the failure stress of a grain boundary in tantalum from molecular-dynamics simulations. Flyer plate simulations were carried out for a handful of boundary types with different energies and excess volumes. These boundaries were chosen as model systems to represent various boundaries observed in "real" materials. For a small, but representative, set of boundaries explored, no direct correlation was observed between the void nucleation stress 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 failure strength of a boundary.