Preparation of Li2TiO3-Li4SiO4-Pb tritium breeding ceramic and its mechanical properties

Abstract

Lithium ternary ceramics are regarded as promising candidates for tritium breeding in the fusion reactor. In this study, the neutron multiplier element, lead (Pb), was mixed into Li2TiO3-Li4SiO4 ceramics to enhance their tritium breeding performance and mechanical properties. The Li2TiO3-Li4SiO4-Pb ceramic powders were synthesized via microwave-induced solution combustion, employing citric acid as the fuel to composite elemental Pb into the ceramics. The ceramic powders were calcined under pure oxygen for the removal of the Li2CO3 impurity and the improvement of the crystallization. The characterization results show that elemental Pb is homogeneously distributed throughout the ceramic body mainly in the chemical form of Li2PbO3. Compared to the conventional Li2TiO3-Li4SiO4 biphasic ceramics, the Li2TiO3-Li4SiO4-Pb ceramics sintered at 1173 K exhibits higher bending strength. The exposure to argon purging gas at high temperatures was conducted to examine the phase stability and mechanical performance with the consideration of tritium recovery working conditions. There is no significant change in the phase composition and bending strength with the exposure duration of up to 60 h.