0.3truein Atomistic simulations using EAM potentials have been used to predict a series of symmetric tilt grain boundary structures of aluminum. Grain boundary energy is related to the interplanar spacing of the grain boundary plane, and the width of most grain boundaries is about 10 . A new energy cusp corresponding to (12) twin structure is observed in the grain boundary energy vs. misorientation angle plot in aluminum.
Grain boundary sliding in four typical boundaries is simulated by applying incremental shear displacements, followed by a complete relaxation under the periodic boundary conditions in grain boundary plane. The number and magnitude of energy barriers (jumps) to GBS are found to be different in different boundary structures. However the magnitude of the energy peaks are found to be lower than that of the energy for two free surfaces, suggesting that the GBS is more favorable than the formation of voids or grain boundary cleavage at very low temperature.