Changes in mechanical property and microstructure of lithium metatitanate tritium breeder caused by thermal annealing

摘要

Changes in mechanical property and microstructure of sintered pebbles of lithium metatitanate (Li2TiO3) and Li excessive lithium metatitanate (Li2+xTiO3, x>0) as tritium breeder pebbles for thermal fusion reactors, which were caused by thermal annealing, were investigated. The compressive strength was measured by using a universal tester. The Li2TiO3 pebble was stable during the thermal annealing at 900 degrees C, and its compressive strength was not decreased. In contrast, the microstructure and Li/Ti ratio of the Li2+xTiO3 pebble were markedly changed during the thermal annealing; the grain growth was severe and the excessive Li was disappeared in a 1000 h annealing. As a result, its compressive strength was significantly changed; it was drastically decreased by a 100 h annealing but it was once increased again in the additional annealing by a change in fracture mode. (C) 2017 Elsevier B.V. All rights reserved.