Intergranular fracture by slip/grain boundary interaction

The role of interaction between slip dislocations and [110] tilt boundaries in crack nucleation has been analyzed for the face-centered cubic (fcc) and L12 structures. Dislocation absorption into the boundaries is orientation-dependent according to the elastic anisotropy. Whenthe transfer of slip across the boundary is impeded, cleavage fracture is predicted on the (1¯11) plane. Intergranular fracture can be initiated when a symmetric double pileup of primary slip dislocations from both sides of the boundary occurs simultaneously. The available experimental data on slip/grain boundary (GB) interaction and intergranular fracture are in good agreement with the present predictions.