A strategy was proposed for the measurement of boundary mobility by using molecular dynamics simulations, and was applied to the migration of nominally-flat <001> tilt grain boundaries; as described by using an EAM potential. The determination of the driving force for boundary migration required that proper account be taken of non-linear elastic effects for strains of the magnitude that was needed for the molecular dynamics simulation of stress-driven boundary migration. The grain boundary velocity was found to be a non-linear function of driving force; especially at low temperatures. Extrapolation of the data to small driving forces permitted the determination of the mobility at all temperatures. The activation energy for grain-boundary migration was found to be 0.26eV. This showed that boundary migration in pure metals was not athermal, but that the activation energy was much smaller than was expected on the basis of experimental measurements.

Computer Simulation of the Elastically Driven Migration of a Flat Grain Boundary. H.Zhang, M.I.Mendelev, D.J.Srolovitz: Acta Materialia, 2004, 52[9], 2569-76