Thermal conductivity of zirconia–alumina composites

Ten mole percent of yttria-stabilized zirconia (10YSZ)–alumina composites containing 0–30 mol% alumina were fabricated by hot pressing at 1500 °C in vacuum. Thermal conductivity of the composites, determined at various temperatures using a steady-state laser heat flux technique, increased with increase in alumina content. Composites containing 0, 5, and 10 mol% alumina did not show any change in thermal conductivity with temperature. However, those containing 20 and 30 mol% alumina showed a decrease in thermal conductivity with increase in temperature. The measured values of thermal conductivity were in good agreement with those calculated from the Maxwell–Eucken model where one phase is uniformly dispersed within a second major continuous phase.