Fabrication and characterization of high-performance Li2TiO3-Li4SiO4 biphasic ceramic tritium breeding cubic unit via digital light processing

Abstract

Li₂TiO₃-Li₄SiO₄ biphasic ceramic has attracted increasing attention because of its unique advantages for tritium breeding in fusion reaction. To overcome the critical limitations of conventional Li₂TiO₃-Li₄SiO₄ pebbles, particularly their inadequate mechanical strength and low packing density, this work developed high-performance Li₂TiO₃-Li₄SiO₄ cubic units via digital light processing (DLP). The purge gas flow behavior in stacked cubic unit structure was studied by Computational Fluid Dynamics (CFD) method to evaluate its structural characteristics. The photosensitivity and rheological properties of precursor suspension were studied to verify the printing feasibility. Solid loading and sintering process were optimized to yield the defect-free Li₂TiO₃-Li₄SiO₄ cubic unit. The results show that the purge gas had periodic velocity distribution and extremely low pressure drop in the stacked cubic unit structure. Li₂TiO₃-Li₂SiO₃-Li₂CO₃ ceramic suspension possessed suitable photosensitivity and thixotropy, and its optimal solid loading was 40 vol%. After sintering at 1100 °C, the Li₂TiO₃-Li₄SiO₄ cubic unit with high relative density (92.8 %TD), high crush load (2000.3 N) and favorable open-pore structure can be prepared. Comparative analyses of Li-based cubic units indicate that the Li₂TiO₃-Li₄SiO₄ cubic unit not only addresses the limitations of single-phase variants but also demonstrates superior intrinsic characteristics, including excellent mechanical& thermomechanical properties and distinct hydrogen isotope release behavior. This work proves the feasibility of Li₂TiO₃-Li₄SiO₄ biphasic strategy and potential of Li₂TiO₃-Li₄SiO₄ cubic units for the future tritium breeding design.