Characterization of Li-rich Li2TiO3 ceramic pebbles prepared by rolling method sintered in air and vacuum

Li2TiO3 with excess Li was developed as an advanced tritium breeder material for fusion reactors. To improve tritium release performance, the breeder pebbles should have a uniform microstructure with small grains. In this work, Li-rich Li2TiO3 ceramic pebbles were fabricated by an efficient spraying-rolling method and were sintered under air and vacuum atmospheres. Results show that the powder calcination temperature has a significant influence on crush load but negligible effect on grain growth. Excess Li2CO3 in pebbles was not just a lithium source to form the Li-rich phase, but also an effective sintering aid to improve sinterability. Small-grained pebbles with dense and homogeneous structure could be obtained by sintering at a low temperature of 1123 K in air. However, when sintered in vacuum, the pebbles exhibit a porous microstructure with very low crush strength. It is indicated that sintering in air is more suitable for the fabrication of Li-rich Li2TiO3 ceramic pebbles.