Superplasticity in zirconia-based ceramics

Following the initial report by Wakai (1986) of an elongation of over 100% in a 3 mol% yttria stabilized zirconia (3YTZ), superplasticity has now been demonstrated in a wide range of zirconia containing ceramics, with a maximum elongation of over 1000% in a glass containing ceramic. The presence of trace impurities can have a very significant effect on the mechanical properties of these ceramics. The report examines data on several superplastic zirconias to evaluate the role of impurities in these materials. It demonstrated that trace impurities appear to facilitate grain boundary sliding in superplastic zirconias, while they apparently hinder grain boundary sliding in superplastic metal