Enhanced sintering rate and finer grain size in yttria-stablized zirconia (3Y-TZP) with combined DC electric field and increased heating rate

The influence of heating rate dT/dt = 2–25 °C/min on sintering of yttria-stabilized ZrO2 (3Y-TZP) powder without and with a small initial DC electric field (E0 = 13.9 V/cm) was determined. An increase in dT/dt and the application of electric field reduced both the sintering time and the grain size at a given density. Employing the master sintering curve approach it was determined that the apparent activation energy Q for sintering was 500 ± 5 kJ/mole, essentially independent of dT/dt and E. A major factor in the effects of dT/dt and E on the sintering rate is their reduction of the grain size. It is proposed that retardation of grain growth by the field results from the interaction of the field with the space charge at the grain boundaries.