Spontaneous microstructural organization under single slip was investigated by transmission electron microscopy. The formation and the structure of dislocation entanglements were analyzed on three types of face-centred cubic-based systems, Al, Cu and TiAl, all deformed by <110>{111} slip. Differences were found that depended upon stacking fault energy and lattice friction. The importance of dipolar configurations was outlined. Selected properties of dipoles were analyzed theoretically under isotropic and anisotropic elasticity in cubic systems. At variance from screw and near-screw dipoles, the stress-free equilibrium angle of an edge dipole was little dependent upon the material's elastic anisotropy. In Cu, for instance, a screw dipole was at equilibrium at around 59° from the slip plane, and this angle was unchanged over a range of dislocation characters of approximately ±20°. On the other hand, given a dipole height, the passing stress was a maximum in the screw orientation. It is, however, not a minimum in the edge orientation. Static and dynamic dipole properties were but little affected by dissociation down to a dipole height of the order of a few times the dissociation distance.

Dislocation Self-Organization under Single Slip Straining and Dipole Properties. Y.L.Chiu, P.Veyssière: Materials Science and Engineering A, 2008, 483-484, 191-4