The concept of cellular dislocations as topological defects in a regular grain array was examined. This furnished experimental evidence which supported the existence of cellular dislocations. Observations were made of deformation relief at the surface of superplastically deformed samples under various strain states, and of the distortion of marker lines due to grain group sliding. These data could be interpreted in terms of cellular dislocations. Finite-element modelling of the sliding of grain groups indicated that stresses and strain were localized within a 2-grain size volume around cellular dislocations.

Cellular Dislocations - Experiment and Modelling. M.Zelin, S.Guillard, A.Mukherjee: Materials Science and Engineering A, 2001, 309-310, 514-9