Superplasticity in ceramics

Although ceramic materials are considered inherently brittle, superplastic behavior has been observed in many fine-grained ceramic materials with large elongation to failure at high temperatures. This paper reviews the major features of superplasticity, the deformation characteristics and mechanism of yttria-stabilized tetragonal zirconia polycrystals, a typical superplastic ceramic, and the effects of dynamic grain growth, glassy phase and concurrent cavitation on the deformation behavior of Y-TZP. The superplastic behavior of other ceramic materials, including Al2O3 Al2O3-Y2O3 stabilized tetragonal zirconia composites, covalent ceramic materials, nanostructured ceramics, and glass-ceramics are also summarized.