Development and comparison of field assisted sintering techniques to densify CeO2 ceramics

Cerium dioxide (CeO2) was densified by conventional and field assisted sintering techniques in order to examine the effect of a range of sintering parameters on the resultant pellet microstructure, namely: temperature, hold time, atmosphere, electric field strength and polarity. CS at 1400 degrees C for 2 h in static air atmospheres provided the highest densities and grain sizes compared with an argon atmosphere, due to the retention of near stoichiometry maintaining sintering kinetics. SPS produced dense ceramics at similar sintering temperatures (1300 degrees C), but with greatly reduced sintering hold (5 min) and cycle times. However, microstructural inhomogeneity arose from the direct current polarity which led to oxygen ion diffusion toward the positive electrode. FS was performed with an alternating current electric field and produces samples of comparable density at sintering temperatures of similar to 1100 degrees C for a hold time of around 1 h with no inhomogeneity due to the alternating current employed.

Automated summary

In this study, cerium dioxide was densified using conventional and field-assisted sintering techniques. The effects of various sintering parameters on the microstructure of the ceramics, including temperature, hold time, atmosphere, electric field strength, and polarity, were examined.