9314825 Mukherjee The purpose of this research is to investigate the phenomenon of superplasticity in an important class of structural ceramics, i.e., nitride ceramics. This is a collaborative investigation leading to a comprehensive framework connecting powder consolidation and formation of micrograined high density nitride ceramics to fabrication processes based on superplasticity. A major theme of the research is the understanding of the mechanisms of superplasticity in submicron non-oxide ceramic materials. Scientific paradigms relevant to superplastic response in non-oxide ceramics are developed by focusing the research on pure and doped aluminum nitride (AIN) and silicon nitride (SiN) and without fluxing additives. Both of these important nitride ceramics will be consolidated by a Plasma Activated Sintering (PAS) process very recently pioneered in Japan and demonstrated to achieve high densities in very short sintering times. %%% In this increasingly energy-conscious industrial age, ceramics are in the forefront as materials destined for use as high temperature structural materials. They have the potential for finding their place in gas turbine engines in propulsion systems and also in terrestrial power plants. Superplasticity brings the additional attractive feature of being a near net-shape forming process, with significant saving in materials and machining costs.