Evaluation of contact strength of Li2TiO3 pebbles with different diameters

Lithium titanate (Li2TiO3) pebbles are considered to be a candidate material of the tritium breeders for fusion reactor from viewpoints of good tritium recovery, chemical stability and other good properties. The pebbles of 0.3–2 mm in diameter have been fabricated by a wet process and its characterization have been performed. Mechanical properties such as compressive strength are necessary for the design of fusion blanket packing the small pebbles. In this study, collapse loads of Li2TiO3 pebbles with different diameters were measured by an unconfined compression tester, and contact strength of these pebbles was evaluated by Hertzian contact theory. In the results, the contact strength of Li2TiO3 pebbles decreased with increasing the radius. The radial strength of Li2TiO3 pebbles was about 1.7 times large as the evaluated compression strength. On the other hand, the contact strength of Li2TiO3 pebbles was also independent of 6Li enrichment.