The proposed research is a study of the relationship between processing, microstructure, and cyclic fatigue behavior in zirconia ceramics. Specifically, the objective of the research is first, to understand the mechanism of cyclic fatigue in these transformation toughened materials, and second, to control this mechanism through processing related changes in the microstructure. A number of in- house processed ceria partially stabilized zirconia/alumina composites will be used in the study to investigate the role of crack shielding and the effects of composition, microstructure, and environment on cyclic fatigue crack propagation. Theoretical calculations on toughening by such mechanisms as transformation zone shielding and crack bridging will also be conducted. It is expected that the results will have a significant impact on our understanding of cyclic fatigue in polycrystalline ceramic materials.
