On the interactions between dislocations and a near-Σ=3 grain boundary in a low stacking-fault energy metal

The interactions of dissociated lattice dislocations with a near-Σ = 3 grain boundary (GB) in copper have been investigated by transmission electron microscopy using the weak-beam technique combined with bright-field image matching. From our observations, Shockley partials are required to recombine when entering the GB to form an absorbed perfect lattice dislocation. Then, decomposition of the latter into two displacement shift complete (DSC) products occurs. Complex reactions between DSC dislocations yield further stress relaxation. The role of the stacking-fault energy in the dislocation–GB interactions is pointed out.