Primary and Secondary Grain Boundary Dislocations in Symmetric Tilt Grain Boundaries of Finite Length

Abstract

AbstractSecondary grain boundary dislocations in large-angle grain boundaries (also called dsc-dislocations) can be described as local variations in the density of the primary (or lattice) dislocations that make up the boundary. We present a simple meso-scale simulation in which the interactions of primary dislocations with each other and with the crystal lattice produce secondary dislocations with smaller Burgers vectors and larger spacing. We use the model to explore the interactions of the primary and secondary defects with a free surface terminating the grain boundary, and demonstrate cases in which the primary dislocations dominate the interactions, forcing the secondary dislocations to increase their energy. Other cases are found, for which all of the dislocations can respond in such a way that their energy decreases. The creation of interfacial disclinations is also demonstrated.