It was recalled that the facts regarding so-called regular deformation bands had been related to the low-energy dislocation structure theory of dislocation-based plasticity. They had prompted an extension of the theory by adding stresses, that were due to strain gradients arising from a changing selection of slip systems, to the previously known dislocation driving-forces. This previously neglected driving force was much smaller than the components which had already been considered; due mainly to the applied stress and to the mutual stress-screening among neighbouring dislocations. It therefore constituted a near-proof of the low-energy dislocation structure hypothesis. The temperature increases that would result from annihilating even the largest deformation bands would amount only to some millidegrees Celsius; thus implying that they, and the entire dislocation structure, were close to thermodynamic equilibrium. This was in marked contrast to the assumption of the alternative, self-organizing dislocation structure model, which proposed that plastic deformation occurred far from equilibrium and was governed by the Prigogine thermodynamics of energy flow-through systems. The above observation also promised future rapid advances in the construction of constitutive equations, since the low-energy dislocation structure hypothesis was the main underpinning of the associated theory of plastic deformation and followed directly from the second law of thermodynamics; in conjunction with Newton's third law. On the other hand, all of the other known models for metal plasticity conflicted with the low-energy dislocation structure hypothesis. With regard to texture modelling, the present analysis showed that Taylor's criterion of minimum plastic work was incorrect, and should be replaced by a criterion of minimum free energy in the stressed state. It was concluded that the low-energy dislocation structure hypothesis was just a special case of a more general low-energy structure hypothesis: which applied to plastic deformation regardless of the deformation mechanism. Plastic deformation was just a means of generating order, and was a by-product of entropy generation while mechanical work was being converted mainly into heat.

Deformation Bands, the Low-Energy Dislocation Structure Theory, and their Importance in Texture Development - II. Theoretical Conclusions. D.Kuhlmann-Wilsdorf: Metallurgical and Metallurgical Transactions A, 1999, 30[9], 2391-406