Fabrication of Li4SiO4 pebbles by a sol–gel technique

Li4SiO4 pebbles are considered as candidate ceramic breeder materials in many blanket designs. In this work, Li4SiO4 pebbles with adequate sphericity were fabricated by a water-based sol–gel process using LiOH and SiO2 (aerosil) as the raw materials, which has not been reported for fabrication of Li4SiO4 pebbles previously. Thermal analysis, phase analysis and morphological observations were carried out systematically. The effects of LiOH/C6H8O7 molar ratios and sintering temperature on the microstructure and density of the pebbles were discussed. Experimental results showed that when the LiOH/C6H8O7 molar ratio was 3, the microstructure of the Li4SiO4 pebbles was the most favorable. While sintered at 900 °C for 4 h, Li4SiO4 pebbles with about 1.2 mm in diameter were obtained and the density of the pebbles achieved about 74%.