Dislocation Walls in Finite Media: The Case of an Infinite Slab

Abstract

ABSTRACTThe dislocation microstructure observed in solids exhibits cellular patterns. The interiors of these cells are depleted of dislocations while the walls contain dense bundles including the geometrically necessary dislocations leading to misorientations of the crystal lattice on either side. This clustering is the result of short-range interactions which favor the formation of dislocation dipoles or multipoles and tilt and twist boundaries. While this short-range ordering of dislocations is readily understood, the long-range pattern formation is still being studied. We examine finite tilt boundaries in an infinite medium, a model grain, and a free slab to investigate the conditions for long-range stress interactions. We find that finite tilt walls in a larger medium generally possess a long-range stress field because the local bending at the tilt wall is constrained by the surrounding material.