Superplastic tensile ductility in a zirconia-dispersed alumina produced by colloidal processing

Substantial superplasticity, where total tensile elongation to failure reaches 550 % at 1773 K, can be attained in a 10-vol%-ZrO₂-dispcrsed alumina when the alumina grain size is reduced to 0.45 μm by colloidal processing. Although the same grain size is attainable by conventional dry processing, the resultant tensile elongation stays about 260%. The examination of undeformed and deformed microstructures revealed that both homogeneous particle dispersion and reduction in the size and density of residual defects in the sintered bodies arc the prerequisites for obtaining large superplastic tensile ductility in zirconia dispersed alumina.