Homogenization treatment to stabilize the compositional structure of beryllide pebbles

Fusion reactors require advanced neutron multipliers with higher stability at high temperatures. Beryllium intermetallic compounds (beryllides) such as Be12Ti are the most promising advanced neutron multipliers. In order to fabricate the beryllide pebbles, a new granulation process has been established that combines a plasma sintering method for beryllide synthesis and a rotating electrode method for granulation. The results of synthesis show that beryllide rod has been successfully fabricated by the plasma sintering method. From this plasma-sintered beryllide rod, prototypic beryllide pebbles of 1 mm average diameter were also successfully fabricated, by the rotating electrode method. Unfortunately, remelting changed the compositional structure of the beryllide pebbles. To homogenize the Be12Ti phase, annealing treatments were examined. The pebble phase was successfully homogenized to a single phase of Be12Ti by annealing either at 1473 K for more than 8 h or at 1673 K for 1 h.