Computer simulation, involving an embedded-atom method potential, was used to study the role which was played by extrinsic grain-boundary defects in sliding of the S11 <101>{131} symmetrical tilt boundary. The sliding resistance of the equilibrium grain boundary was deduced by calculating the dependence of the boundary energy upon the in-plane translation of one grain relative to the other. Low-energy faulted structures were found which corresponded to unstable intermediate states and to the presence of stable partial grain boundary dislocations. Extrinsic dislocations and disconnections were found to lower the sliding stress significantly, relative to the equilibrium grain boundary.

Effect of Extrinsic Grain-Boundary Defects on Grain-Boundary Sliding Resistance. R.J.Kurtz, R.G.Hoagland, J.P.Hirth: Philosophical Magazine A, 1999, 79[3], 665-81