Photopolymerization and reaction sintering enabled generative shaping and material-forming of complex ceramic structures with high performance

This study presents a novel combined generative shaping and material-forming (GSM) approach for preparing tritium breeder units for fusion reactors using 3D printing technology. For the first time, defect-free lithium-rich Li4SiO4 porous structures were successfully prepared by combining photopolymerization and reaction sintering processes based on the use of low-cost Li2CO3 and SiO2 ceramic powders. Investigation was conducted on the preparation of the ceramic powder-based mixture slurry as well as the photopolymerization 3D printing and reaction sintering processes. Li4SiO4-based porous lattice ceramics with high purity, no obvious defects, and adjustable packing fraction were fabricated. The mechanical properties of the samples prepared with different packing fractions were then evaluated. The prepared samples showed better mechanical properties than the pebble bed structures with similar packing fractions. At a packing fraction of 92.10%, the crushing strength and elastic modulus reached 186.49 ± 0.04 MPa and 16.47 ± 0.03 GPa, respectively. These results show that the combination of photopolymerization 3D printing and reaction sintering processes based on the use of low-cost ceramic powders has significant advantages in terms of flexibility and efficiency in structure design and fabrication and cost-effectiveness in material forming with enhanced performance, providing a promising route to produce high-performance tritium breeder structures for fusion technologies. In particular, the present combined method also paves a promising generalized way to enable effective generative structure-shaping and material-forming in the advanced ceramic manufacturing industry, not to mention that the preparation of high-performance Li4SiO4 tritium breeder units for fusion technologies.