Spreading of dislocation cores in elastically anisotropic body-centered-cubic materials: The case of gum metal

The structure of dislocation cores in elastically anisotropic materials is considered. A definition of the dislocation core radius is introduced and used to demonstrate that the elastic anisotropy that develops near a composition driven phase transition, such as that predicted for the Ti-Nb based alloys known as gum metals, can drive dislocation core radii to infinity. Under these circumstances, dislocation cores necessarily overlap. The atomic scale structures predicted to arise from core overlap in Ti-V alloys are reminiscent of nanodisturbances observed in gum metals.