Fabrication of the Li2TiO3 tritium breeder pebbles by a capillary-based microfluidic wet process

Li₂TiO₃ is one of the most promising candidates among tritium breeders. In this work, Li₂TiO₃ pebbles with a narrow size distribution, high density, small grain size, and good sphericity are synthesized using the commercial Li₂TiO₃ powder as the raw material by a co-flow capillary-based microfluidic wet process. Highly uniform slurry droplets containing Li₂TiO₃ powder and polyvinyl alcohol were formed in the microfluidic device and then solidified with the cross-linking reaction between polyvinyl alcohol and borax. Li₂TiO₃ pebbles were finally obtained after sintering the green bodies. The size of sintered Li₂TiO₃ pebbles with a good sphericity (D_max/D_min < 1.05) can be controlled precisely in a size range of 400–1000 µm by adjusting the flow rate of disperse and continuous phases. The effects of the calcination method, sintering condition, solid content of slurry, and the particle size of Li₂TiO₃ powder on the relative density of Li₂TiO₃ pebbles prepared were studied in detail, and 97.16% T.D. (Theoretical Density) maximum relative density of the pebbles with 5 µm grain size were fabricated.