Zhou Wenlong

High strain rate superplasticity in oxide ceramics

Oxide ceramic is a structural material with excellent mechanical properties and wide applications. Due to its inbeing brittleness, superplastic forming provides a feasible approach to process the structural oxide ceramics. However, low strain rate is a serious limitation on superplasticity applications of the oxide ceramics in the future. This paper reviewed experimental results and superplastic models in some recent reports, and focused on the major factors limiting the deformation strain rate, such as: Grain size, dynamic grain growth, grain boundary diffusivity, chemical bonding state, grain boundary state, cavity nucleation and growth. Some existing basic and new approaches to achieving high strain rate superplasticity in oxide ceramics were summarized. The superplastic behaviors and enhancement mechanisms were also discussed.