This volume constitutes the Proceedings of a Symposium on the Plastic Deformation of Ceramic Materials, held at The Pennsylvania State University, University Park, Pennsylvania, July 17, 18, and 19, 1974. The theme of this conference focused on single crystal and polycrystalline deformation processes in ceramic materials. The 31 contributed papers by 52 authors, present a current understand- ing of the theory and application of deformation processes to the study and utilization of ceramic materials. The program chairmen gratefully ackwledge the financial assistance for the Symposium provided by the United States Atomic Energy Commission, The National Science Foundation, and The College of Earth and Mineral Sciences of The Pennsylvania State University. Special ackwledgment is extended to Drs. Louis C. Ianniello and Paul K. Predecki of the AEC and NSF, respectively. Of course, the proceedings would t have been possible without the excellent cooperation of the authors in preparing their manuscripts. Special appreciation is extended to the professional organi- zation services provided by the J. Orvis Keller Conference Center of The Pennsylvania State University. In particular, Mrs. Patricia Ewing should be ackwledged for her excellent program organization and planning. Finally, we also wish to thank our secretaries for the patience and help in bringing these Proceedings to press.