Joining alumina/zirconia ceramics

Dense compacts consisting of 40 vol.% Al2O3–60 vol.% 3 mol% Y2O3-stabilized ZrO2 (YSZ) were joined with an interlayer of 50 vol.% Al2O3–50 vol.% YSZ. A joint was also made at 1200 °C with an interlayer that was 50 vol.% Al2O3–50 vol.% ZrO2, in which the average particle size of both powders was ≤20 nm. The joint materials were applied by aerosol spraying, and thus the technique is suitable for commercial application. Superplastic deformation at 1200–1350 °C required ≤2 h to form fully dense joints in which minimal grain growth occurred. Virtually perfect joints were also made with various other ratios of Al2O3–YSZ.