Liquid phase sintering of Y-TZP with CuO and Y2Cu2O5 dopants

Effects of CuO and Y2Cu2O5 addition on the sintering ability and the phase stability of Y-TZP (Yttria doped Tetragonal Zirconia Polycrystals) were studied. Both of the dopants were found to be quite effective in reducing the sintering temperature to attain full density and refusing the grain size. Cu ions were easily dissolved into the matrix during sintering leaving no grain boundary phase. Since the dissolved Cu ions have a destabilizing effect on the tetragonal lattice the maximum allowable concentration of the depants were limited to 0.3 mol% for CuO and 0.5 mol% for YCuO2.5 to maintain fully tetragonal phase. With the addition of these dopants, the bending strength decreased by 18% in comparison with the undoped specimen but the fracture toughness increased by 10 to 20%.