Elongation to failure in the model of cooperative grain boundary sliding

The macroscopic effect of neck development characterizing the termination of superplasticity has been studied reasoning from certain assumptions on the deformation mechanism at the mesoscopic level. It has been established that characteristics of ultimate ductility can be described in terms of deformation-induced space-non-uniformity of a distribution of cooperative grain boundary sliding bands, and there is no need to introduce the term of macro-non-uniformity, namely, a neck nucleus initially present in the sample.