Embedded-atom method interatomic potentials, and molecular statics and dynamics calculations were used to study the sliding and migration of [110] symmetrical tilt grain boundaries under both applied displacement and force conditions. For equilibrium grain boundaries (with no applied displacement or force), 3 low-energy configurations (corresponding to 3 twin structures) were found in the [110] symmetrical tilt grain boundary structures when the grain boundary energies at 0K were calculated as a function of the grain misorientation angle. So-called pure grain-boundary sliding, without migration, was simulated by applying an external displacement. When forces were applied, the energy barriers were reduced due to the fact that grain-boundary sliding of symmetrical tilt grain boundaries was always coupled with migration. The tendency to pure grain-boundary sliding was estimated by calculating the energy which was associated with incremental equilibrium configurations during sliding. This was compared with the case where sliding was accompanied by migration. The height of the energy barriers was found to be much higher in pure grain-boundary sliding than it was when migration accompanied sliding. Relationships were established between the applied force, internal-stress field and displacement field, and the effect of the grain-boundary structure upon the deformation process was considered. It was found that the grain-boundary sliding displacement was proportional to the applied force, grain-boundary energy, and time.

Atomistic Simulation of Grain Boundary Sliding and Migration. N.Chandra, P.Dang: Journal of Materials Science, 1999, 34[4], 655-66