Enhanced electrical conductivity of ultrafine-grained 8Y2O3 stabilized ZrO2 produced by two-step sintering technique

Two-step sintering of nanocrystalline zirconia powder stabilized with 8 mol% yttria resulted in remarkable enhancement of the electrical conductivity and significant suppression of the accelerated grain growth. The electrical conductivity of the nearly full-dense structures obtained with an average grain size of 2.15 μm at 900 °C was ∼107 mS/cm. Two-step sintering resulted in reduction of the grain size to less than 300 nm and increase of the electrical conductivity to 209 mS/cm (i.e. >95% increase). These changes accompanied with a fracture toughness increase of more that 95% (from 1.61 to 3.16 MPa m1/2), too.