Precise Direction of Symmetrically Tilt Small Angle Boundaries Developed during Recrystallization of Cross Rolled Aluminium

Abstract

A 6°and 3° [001] symmetrical tilt small angle grain boundaries in Al obtained by cross rolling and annealing have been investigated by High Resolution Electron Microscopy (HREM) and Molecular Dynamic Simulation (MDS) techniques. Both HREM and simulated images reveal that the grain boundary planes in these boundaries run along a direction that is close to , but the simulated images give a more precise direction of the grain boundary plane. The simulated images reveal that the boundaries in their lowest energy configuration follow a direction that lies along a lattice vector that has either the magnitude of the square root of a non- prime odd integer or an integral multiple of a non-prime odd integer. The relationships between grain boundary plane and the lattice vector with the magnitude that is the square root of a nonprime odd integer and run along the grain boundary will be discussed in the light of the alignment of dislocations in the formation of small angle grain boundaries.