It was recalled that dislocations commonly formed planar arrays that minimized the free interfacial energy between mismatched crystal volumes. In epitaxy and in phase transformations, the misfit arose from differences in lattice structure and/or orientations of different phases. In deformed homogeneous crystalline materials, the planar dislocation arrays were grain and mosaic block boundaries that accommodated relative misorientations within the same crystal structure. Thus, planar dislocation arrays had a common origin (minimization of interfacial energies) and were therefore all subject to the low-energy dislocation structure hypothesis. Specific applications of this general principle were well-advanced in the case of epitaxy, and phase or grain boundaries. However, the principle was overlooked or denied in connection with plastic deformation. It was pointed out here that, while being formed, dislocation structures due to plastic deformation were in thermodynamic equilibrium. By firmly establishing the link between planar dislocation arrays of all types, the kinship between epitaxy and plastic deformation of crystalline materials was demonstrated.

Why Do Dislocations Assemble into Interfaces in Epitaxy as Well as in Crystal Plasticity to Minimize Free Energy. D.Kuhlmann-Wilsdorf: Metallurgical and Materials Transactions A, 2002, 32[8], 2519-39