Field‐assisted processing of Ce–zirconolite ceramics for nuclear applications

Abstract Conventional, flash, and hybrid sintering (unique combination of conventional and microwave heating) experiments were performed on 10% Ce‐doped zirconolite samples and the results were compared. Ce–zirconolite was prepared using reactive, pressure‐less, field‐assisted hybrid processing directly from the precursor made using commercial chemical agents, viz., CaTiO ₃ , ZrO ₂ , TiO ₂ , and CeO ₂ at 1350°C/2 h. For comparison, Ce–zirconolite ceramics were produced by the conventional synthesis at 1350°C/72 h and then sintering at 1450°C/10 h based on a literature methodology. The Ce–zirconolite samples were also flash sintered for the first time at 1100°C in just 5 min with the application of an AC field to ∼98% density with a finer grain size. A novel reactive flash synthesis procedure of zirconolite precursors with subsequent flash sintering was also explored. The flash process for both synthesis/sintering needs only ∼15% of the energy (85% savings) and hybrid method requires ∼ 33% (67% savings) of the total energy, respectively, when compared to the values reported for conventional synthesis and sintering processes together for zirconolite manufacturing. Thus, both the field‐assisted processing techniques were found to be highly energy efficient for the fabrication of Ce‐zirconolite ceramics, making them suitable for applications in Plutonium‐based nuclear waste disposal.