Molten LiF additive promoted low‐temperature densification in sintering Li 2 TiO 3 ceramic pebbles

Abstract Li 2 TiO 3 ceramics are promising for tritium breeding applications in nuclear fusion energy considering the chemical inertness and tritium release performance. To solve the synthesis problems of Li 2 TiO 3 pebbles (including lithium loss at high‐temperature, microstructure coarsening, and poor mechanical properties), alkaline metal halides are incorporated to fabricate Li 2 TiO 3 ceramic pebbles with good performance. Besides, this study provides an in‐depth investigation into how the additive influences the shrinkage, internal structural evolution, grain size, and crushing load of Li 2 TiO 3 ceramic pebbles. Compared with LiCl, addition of LiF can obviously reduce the particle size and increase the relative density of Li 2 TiO 3 samples at a lower sintering temperature. Meanwhile, the results show that the Li 2 TiO 3 breeder ceramics sintered at 950°C have optimal properties, including 1.68 µm average grain size, 92.9% relative density, and an excellent crushing load of 140.8 N, which are superior over those of the pebbles obtained through traditional methods. Besides, it also exhibits excellent structure stability and the types of deuterium and tritium released are D 2 O and HTO, respectively. This research not only facilitates the low‐temperature densification of Li 2 TiO 3 ceramic pebbles but also guides the microstructure design of ceramic pebbles, which offers promising potential in enhancing the service performance of tritium breeding materials within reactor blankets.