Densification of nano-CeO2 ceramics as nuclear oxide surrogate by spark plasma sintering

The sintering and resulting microstructure of nano-grained CeO2 ceramics were investigated as functions of the spark plasma sintering (SPS) parameters. Ceria powders could be sintered to a relative density over 97% with a grain size of about 30 nm. The applied uniaxial pressure during sintering had a significant effect on densification. The combination of high pressure and fast heating rate produces a marked reduction in the sintering temperature to densify CeO2 with very limited grain growth. Heating rate and holding time, however, had insignificant effect on density but a measurable effect on grain size.