Electron optical experiments on Al foils had revealed individual dislocations in the interior of the metal. The arrangement and movement of individual dislocations were observed. Most of the dislocations occurred in the boundaries of a sub-structure, the diameter of the sub-grains being of the order of 1μ or more. Tilt-boundaries, networks and dislocation nodes were resolved. The results apply to Al recovered at 350C after heavy deformation by beating; the dislocation density was 1010/cm2. The dislocations could be seen to move along traces of (111) slip planes; the motion of the dislocations could be either rapid or slow and jerky. Cross-slip by the screw dislocation mechanism was observed frequently.

Direct Observations of the Arrangement and Motion of Dislocations in Aluminium. P.B.Hirsch, R.W.Horne, M.J.Whelan: Philosophical Magazine, 2006, 86[29-31], 4553-72