Y-TZP nanostructures with non-homogeneous yttria distribution for improved hydrothermal degradation resistance and mechanical properties

Dense and homogeneous nanostructured Y-TZP ceramics were prepared by colloidal processing and 2-step sintering using commercial powders. The influence of non-homogeneous yttria distributions on mechanical properties and Low-Temperature Degradation (LTD) resistance were assessed. Physical, structural, microstructural, and mechanical characterizations of all groups were evaluated and compared before and after artificial aging. Nanostructured Y-TZP samples with non-homogeneous yttria distributions presented the highest fracture toughness and elevated fracture strength. These samples were susceptible to LTD, but with the transformed monoclinic phase fraction restricted to the near-surface region. The characterization data of nanostructured samples were compared to those of conventional 3Y-TZP. The results of this work indicate that it may be possible to prepare Y-TZP ceramics with improved mechanical properties and resistance to LTD by careful and systematic design and engineering of nanostructures.