A computer simulation was performed of the intersection of a [110] edge dislocation with a Σ11 <101>{131} grain boundary. An interesting result was that partials in a mirror dislocation problem behaved differently on one side of the grain boundary than on the other. This was suggested to reflect differences in the elastic interactions between each dislocation segment and its image in the neighboring grain. The dislocation obviously reacted differently when approaching the boundary from a different angle. Another factor in the rotated case was that the relatively lower angle of incidence of the dislocation, to the grain boundary in the lower grain, spread the interaction (of dislocation cores with grain boundary atoms) over a larger region than in the upper grain. In the reflected problem, a near-symmetry of the relaxed configuration mirrored the symmetry of the initial conditions. The problem was not truly symmetrical, because the layer of grain boundary atoms about which the grains were mirrored had to reside in one grain or the other (here the upper one) when rigid-body translations were performed. An apparent increase in separation of the partials upon entering the grain boundary region was to be expected, since the stacking fault energy in the grain boundary region could be different to that in the perfect crystal. In both cases, disregistry analyses failed 1 or 2 atom planes from the grain boundary, thus indicating a region over which atom displacements did not fall into the recognizable patterns of the partial dislocations. Short segments of grain boundary dislocation existed and provided continuity of the dislocation across the grain boundary. In the reflected problem, a grain boundary dislocation with a Burgers vector of 4/33[13¯1] satisfied this requirement. The grain boundary dislocations were not well-defined because they were obscured by the core-atom displacements in the 4 partial dislocations which entered the grain boundary.

Computer Simulation of a [110] Edge Dislocation Intersecting a Σ11 <101>{131} Grain Boundary in Aluminum H.L.Heinisch, R.G.Hoagland, R.J.Kurtz, J.P.Hirth: Scripta Materialia, 1998, 39[4-5], 451-6