Processing and Structural Characterisation of 3Y-TZP Ceramics Resistant to Hydrothermal Ageing

Doped tetragonal zirconia polycrystals (TZP's) have been prepared by the addition of 0, 0.05 and 0.25wt% Al sub 2 O sub 3 to a 3 mol% ZrO sub 2 powder via co-milling. A modal grain size of 0.34-0.38 mu m and fracture toughness K sub 1c in the range 7.5-7.9 MParoot m was achieved for all samples after sintering at 1450 deg C for 3 hours. The addition of trace Al sub 2 O sub 3 is shown to have a profound effect on the materials resistance to hydrothermal ageing which was found to increase in the order 0 < 0.05 < 0.25wt% Al sub 2 O sub 3 .