Fabrication of Li₂TiO₃Pebbles by Lithium Solution Penetration Method

Abstract

To fabricate spherical lithium titanate (Li 2 TiO 3 ) pebbles which are used for a breeder material in fusion reactor, titanium oxide (TiO 2 ) granules were used as a starting material. The granules were pre-sintered, and then aqueous lithium nitrate solution infiltrated into the granules at vacuum condition. The granules were crystallized to Li 2 TiO 3 after sintering under the control of process parameters. In this study, the concentration of lithium in the solution, as well as the number of penetration times and sintering temperature affected the final crystallite phase and the microstructure of the pebbles. In particular, the sphericity and size of the pebbles were effectively controlled by a technical rolling process. The useful spherical Li 2 TiO 3 pebbles which have 10 ~20% porosity and 60 ~120 N compressive strength were obtained through the sintering at 1000 ~1100 o C in the multi-times infiltration process with 50 wt% solution. The physical properties of pebbles such as density, porosity and strength, can be controlled by a selection of TiO 2 powders and control of processing parameters. It can be thought that the lithium penetration method is a useful method for the fabrication of mass product of spherical Li 2 TiO 3 pebbles.