The dislocation structures introduced by the cyclic deformation of Cu-16at%Al single crystals oriented, typically along [¯123] for single slip and [023] and [117] for double slip, were studied by transmission electron microscopy and compared with results for Cu single crystals. In distinct contrast to the dislocation structures of Cu single crystals having the corresponding orientations, the dislocation structures of these oriented Cu-16at%Al alloy single crystals exhibited a typical planar morphology. As the applied plastic strain amplitude increased, the dislocation configuration generally changed from multipolar arrays to dislocation tangles in the primary slip plane, and from low-density planar slip bands to well-developed persistent Lüder's bands in the planes normal to the primary slip plane, respectively. Secondary slips could be clearly observed to activate from very low plastic-strain amplitudes in all three Cu-16at%Al single crystals

investigated. The crystallographic orientation had almost no effect upon the dislocation structure of Cu-16at%Al single crystals.

Orientation Dependence of Dislocation Structures in Cyclically Deformed Cu-16at%Al Alloy Single Crystals. X.W.Li, X.M.Wu, Z.G.Wang, Y.Umakoshi: Metallurgical and Materials Transactions A, 2003, 34[2], 307-18