Electric Field Assisted Sintering of Cubic Zirconia at 390°C

Using the flash sintering technique, cubic yttria-stabilized zirconia is shown to sinter at 390 degrees C, more than 1000 degrees C below nominal sintering temperatures, by using a DC electric field of 2250V/cm. Furthermore, flash sintering experiments performed with electric fields between 60 and 2250V/cm were used to show that the relationship of the temperature at the onset of flash sintering (TOnset) and the applied field (E) follows the power relationship TOnset (K)=2440 E1/5.85(V/cm). Using this relationship, and considering the sintering of the sample in the absence of an electric field, the critical electric field to enter the flash sintering regime is shown to be 24.5V/cm. For electric fields between this critical electric field and 2250V/cm, the onset of flash sintering occurs in the same range of critical volumetric power dissipation, between 1 and 10mW/mm3, suggesting this is a material property. Despite the volumetric power dissipation being the critical value for the onset of flash sintering behavior, the current density achieved during sintering appears to be more critical for densification rather than maximizing power dissipation.