<110> symmetric tilt grain-boundary structures in fcc metals with low stacking-fault energies

Twenty-one [110] symmetric tilt grain boundaries (GB's) are investigated with atomistic simulations, using an embedded-atom method (EAM) potential for a low stacking-fault energy fee metal. Lattice statics simulations with a large number of initial configurations are used to identify both the equilibrium and metastable structures at 0 K. The level of difficulty in finding the equilibrium structures is quantitatively assessed. The stability of the structures at an elevated temperature is investigated by Monte Carlo annealing. A form of GB dissociation is identified in a number of the boundaries. These structures are used to develop a dislocation model of GB dissociation by stacking-fault emission. Also, an attempt is made to apply the structural unit model (SUM) to the simulated boundaries and problems that are encountered for GB structures in low stacking-fault energy metals are enumerated and discussed.