固态氚增殖材料Li_4SiO_4陶瓷微球的制备

Preparation of Li_4SiO_4 solid tritium breeding ceramic pebbles

锂基陶瓷是氚增殖材料的主要选材料之一。以正硅酸乙酯和硝酸锂为主要原料,采用溶胶-凝胶法合成了Li4SiO4陶瓷粉体,利用湿法成球技术制备了毫米级Li4SiO4陶瓷微球。结果表明:PH值对Li4SiO4陶瓷粉体的相结构有较大影响。在中性和酸性条件下得到的是Li4SiO4与Li2SiO3的混合相,而在碱性条件下得到的是纯Li4SiO4相。凝胶剂质量分数在10%的时候能得到球形度跟强度都好的陶瓷球。950℃为Li4SiO4陶瓷微球的最佳烧结温度,此时烧结的陶瓷球的密度最大,为理论密度的85.48%。该研究为获得低成本、高性能的锂基陶瓷微球提供了依据。

Lithium-based ceramics has been considered as candidate for tritium breeding materials in ITER test blanket module（TBM）.This paper describes the synthesis of Li4SiO4 ceramic powders by using（C2H5）4SiO4 and LiNO3 as raw materials by sol-gel method,and the preparation of the Li4SiO4 pebbles with the diameter of about 1 mm by wet method.The results show that the pH values exert a significant effect on the crystal phase of Li4SiO4 ceramic powders.Neutral and acidic sol solution tends to produce the mixture phase of Li4SiO4 and Li2SiO3 while alkaline condition only yields the single phase of Li4SiO4.The amount of gelator of 10% results in Li4SiO4 ceramic pebbles of desired intensity and sphericity and 950 ℃ represents the best sintering temperature for the ceramic microspheres Li4SiO4,capable of the ceramic balls of the maximum density,85.48% of the theoretical density.This study provides a basis for preparing lithium-based ceramics pebbles of higher performance and lower cost.