The relationship between polycrystalline deformation and monocrystalline deformation was studied. It was recalled that grains of differing orientation, embedded in polycrystalline materials, deformed on different slip planes and led to the evolution of deformation microstructures with various characteristics and with various dislocation-density/strain relationships. The separation of the grains in a polycrystal, into groups having different orientations of the tensile direction, here permitted a comparison of the stress-strain behaviour of grains in a polycrystal to be made with that of single crystals. This comparison showed that the understanding of the relationship between polycrystalline deformation and monocrystalline deformation was greatly furthered by studies of the relationship between grain orientation and the characteristics of the deformation microstructure.

Dislocation Structures and Flow Stress. N.Hansen, X.Huang: Materials Science and Engineering A, 1997, 234-236, 602-5