Fabrication and Mechanical Property of Li₄Ti_xSi_1-xO₄ Ceramic Tritium Breeders

Lithium orthosilicate(Li₄SiO₄) is considered as the promising ceramic tritium breeder materials for the International Thermonuclear Experimental Reactor(ITER) due to its high lithium density and good tritium release property. The mechanical property of the ceramic breeder material will be improved by hetero-element doping and forming solid solution. In this study, Li₄Ti_xSi_1-xO₄ pebbles with high density and good sphericity were fabricated by melt spraying method with the powders synthesized by solid state reaction. The microstructure of the pebbles was improved by doping Ti, thus increasing the crush load. The results indicate that the crush load of Li₄SiO₄ pebbles is decreased with the increasing of temperatures, the crush load is only 10.2 N for the pebble annealed 2 h at 800 ℃. Compared to Li₄SiO₄ pebbles, the mechanical property of Li₄Ti_0.1Si_0.9O4 is significantly improved, and the crush load is as high as 26.2 N annealed 2 h at 800 ℃. Besides, the Li₄Ti_0.1Si_0.9O4 pebbles also show considerable stability.