(PLEASE NOTE SEMINAR LOCATION OUTSIDE OF ARMS) MATERIALS SCIENCE AND ENGINEERING SEMINAR Processing and Mechanical Properties of Silicon Nitride Nanoceramics by Andrew Rosenberger Ph.D. Prelim Exam - Part I Advisor: Prof. L. Stanciu ABSTRACT Silicon nitride is an engineering ceramic in limited use as components for automotive and aerospace applications. Reducing the grain size from the micron scale to the nanocrystalline level offers possibilities of enabling alternate processing techniques and enhancing mechanical properties. Experimental research has overcome the various processing and sintering difficulties necessary to produce silicon nitride nanoceramics and found significant improvements in hardness, wear resistance, and superplasticity. These improvements were attributed mainly to the reduced flaw size and enhancement of grain boundary sliding. Theoretical models have also been developed which describe possible mechanisms for improved toughness, but their applicability to actual materials is uncertain. Further research into microstructure control on the nanometer scale is proposed, as are methods to verify and apply the theoretical models of deformation. Date: Wednesday, November 14, 2012 Time: 11:30 A.M. Place: HAMP 2107 Lisa Stacey Secretary/Development Assistant Purdue University School of Materials Engineering 765/494-4100