High-resolution transmission electron microscopy of nanotwinned Cu films revealed Σ3 {112} incoherent twin boundaries, with a repeatable pattern involving units of three {111} atomic planes. Topological analysis shows that Σ3 {112} incoherent twin boundaries adopt two types of atomic structure with differing arrangements of Shockley partial dislocations. Atomistic simulations were performed for Cu and Al. These studies revealed the structure of the two types of incoherent twin boundaries, the formation mechanism and stability of the associated 9R phase, and the influence of stacking fault energies on them. The results suggest that Σ3 {112} incoherent twin boundaries may migrate through the collective glide of partial dislocations.

Dislocation Structures of Σ3 {112} Twin Boundaries in Face Centered Cubic Metals. J.Wang, O.Anderoglu, J.P.Hirth, A.Misra, X.Zhang: Applied Physics Letters, 2009, 95[2], 021908