The superplastic deep drawing of a fine-grained alumina-zirconia ceramic composite and its cavitation behavior

The synthesis, superplastic deep drawing and cavitation behavior of a fine-grained alumina-zirconia ceramic composite have been investigated. The results show that dense Al₂O₃/ZrO₂ samples with average grain diameter of 230nm can be elongated to a dome height of at least 12mm at the punch rate of 0.6mm·min^-1 at 1400°C. Deformed microstructure of the material indicates that not only the nucleation and growth of internal cavities are effectively suppressed but also the intragranular dislocation structures and sub-boundaries are observed around the nano-particles in alumina grains, which proves that intragranular dislocation creep is playing an important role in deformation. While the research on the deep drawing of the materials with the initial average grain size of 450nm conforms that a plasticity controlled cavity growth process takes place during deformation.