A well-organized dislocation structure forms in many polycrystalline metals during plastic deformation. This structure was described qualitatively with no explanation of the quantitative characterization. Here, the evolution of dislocation structure in commercial purity aluminium was described by means of the excess dislocation density and by quantitative characterization of the cell structure as seen on a plane surface. The measurements were performed on a pseudo-internal surface of a split specimen deformed by channel die deformation. The results showed a clear dependence of cell structure formation upon orientation of the crystallite with respect to the imposed deformation gradient with the largest excess dislocation density occurring in grains of {011}[122] orientation for plane strain deformation. Neighboring grain and non-local effects were shown to be of importance in the type of dislocation structures that evolved.

Orientation Dependence of Dislocation Structure Evolution during Cold Rolling of Aluminium. C.C.Merriman, D.P.Field, P.Trivedi: Materials Science and Engineering A, 2008, 494[1-2], 28-35