Geometrical aspects of superplastic flow

A number of models have been proposed in order to describe the geometrical aspects of the progress of superplastic deformation. Geometrical models of superplastic flow considering sliding of individual grains and models of cooperative grain boundary sliding (CGBS) have been critically analyzed. Experimental evidence supporting models that treat CBGS as a sequential sliding of grains has been presented. This approach is further developed in terms of movement of cellular dislocations in two-phase materials.