Formation of Zirconia Solid Solutions Containing Alumina Prepared by New Preparation Method

In the system ZrO 2 –Al 2 O 3 , a new method for preparing ZrO 2 solid solutions from ZrCl 4 and AlCl 3 using hydrazine monohydrate is investigated. c ‐ZrO 2 solid solutions containing up to ∼40 mol% Al 2 O 3 crystallize at low temperatures from amorphous materials. The formation mechanism is discussed from IR spectral data. The values of the lattice parameter α increase linearly from 0.5072 to 0.5105 nm with increasing Al 2 O 3 content. At higher temperatures, transformation of the solid solutions proceeds as follows: c ( SS ) → t ( ss ) → t ( ss ) +α‐Al 2 O 3 → m +α‐Al 2 O 3 . m ‐ZrO 2 –α‐Al 2 O 3 composite ceramics are fabricated by hot isostatic pressing for 2 h at 1250°C and 196 MPa. Microstructures and mechanical properties are examined, in connection with increasing Al 2 O 3 content.