SUMMARY
Micrograin Superplasticity refers to the ability of fine-grained materials (1μm < d < 10
μm, where d is the grain size) to exhibit extensive neck-free elongations during
deformation at elevated temperatures. Over the past three decades, good progress
has been made in rationalizing this phenomenon. This presentation provides a brief
review on this progress in several areas that are related to: (a) the mechanical
characteristics of micrograin superplasticity and their origin, (b) the effect of impurity
content and type on deformation behavior, boundary sliding, and cavitation during
superplastic deformation, (c) the formation of cavity stringers, (d) dislocation
activities and role during superplastic flow, and (e) the utilization of superplasticity