Statistical aspects of low temperature discontinuous deformation

To summarize we point out the following. 1. (i) There is an analogy in macroscopic stress behaviour of discontinuous flow associated with thermomechanical instability or Portevin-Le Chatelier effect. It may be suggested that statistics of these types of plastic instability do not depend on the particular mechanism but are governed by common laws. 2. (ii) The manifestation of a power law in distribution densities, being a sign of self-organization in the dislocation dynamics, depends on the material and on deformation conditions. 3. (iii) In order to draw definite conclusions about the nature of common features of the phenomenon of plastic instability it would be interesting to study simultaneously the macroscopic parameters of deformation curves and “mesoscopic” ones, namely the electric responses to the defect motion. Investigations of the size effect on statistics might also shed light on the problem.