Low temperature and high strain rate superplastic flow in structural ceramics induced by strong electric-field

High-strength structural ceramics with sub-micron grain sizes can exhibit superplasticity , but the superplasticity appears at high temperatures and low strain rates . Low temperature and high speed superplastic flow in structural ceramics was achieved by applying a strong electric field above a threshold value during deformation. The application of a direct-current field of 190 V·cm − 1 led to superplastic deformation in Y 2 O 3 -stabilized tetragonal ZrO 2 polycrystal with a total tensile elongation of > 150% at 800 °C and an initial strain rate of 2 × 10 − 3 s − 1 . The field-activated plasticity was attributed to highly-accelerated self-diffusion induced not only by temperature rise but also by a field effect.