Creep behavior of zirconia ceramics under a strong DC field

The tensile creep of 3 mol% Y2O3 stabilized tetragonal ZrO2 ceramics under a DC field was systematically investigated. The results show that the deformation mechanism of the material strongly depends on the current density and the applied stress. Exceptionally large uniform elongation can be obtained only when the creep is dominated by dislocation accommodated grain-boundary sliding. A maximum uniform elongation of ∼300% is achieved at a strain rate close to 10−3 s−1. At an even higher strain rate of about 10−2 s−1, uniform elongation is still near 100%. The current results suggest that high strain rate superplasticity can be induced by applying a strong electric field at proper stress and current density.