Two- and three-dimensional modeling studies of the interactions between dislocations and grain boundaries in face-centered cubic metals were described. These included 2-dimensional simulations of lattice dislocation interaction with Σ11 tilt grain boundaries. Studies of a Σ11 symmetrical tilt grain boundary revealed that transmitted dislocations resulted in local grain boundary migration and disconnection formation. A classical elastic analysis yielded correct predictions in one case, but not another. Glissile grain boundary dislocations were created in this process; implying that part of the transmitted dislocation was absorbed. Calculations of lattice dislocations, interacting with a Σ11 asymmetrical tilt grain boundary, showed that the nature of the interaction depended upon the local grain boundary structure. In some cases, transmission was observed to occur on planes that did not have the highest resolved glide stress. The results of large-scale 3-dimensional molecular dynamic simulations were also described. These included the investigation of the interaction between dislocations nucleating from a crack tip, and of a number of symmetrical tilt grain boundaries. By using a line-tension model to analyze the data, it was found that the results of dislocation/grain-boundary collisions could be rationalized in terms of just 3 geometrical parameters.

Modeling of Dislocation Grain-Boundary Interactions in FCC Metals. M.de Koning, R.J.Kurtz, V.V.Bulatov, C.H.Henager, R.G.Hoagland, W.Cai, M.Nomura: Journal of Nuclear Materials, 2003, 323[2-3], 281-9