正硅酸锂氚增殖材料结构改性及机械性能研究  

Structural Modification and Mechanical Properties of Lithium Orthosilicate Tritium Breeding Materials

作　　者：周启来[1] 张裕国 许义福 ZHOU Qilai;ZHANG Yuguo;XU Yifu(School of Materials Science and Engineering,Wuhan University of Technology,Wuhan 430070,Hubei,China)

机构地区：[1]武汉理工大学材料科学与工程学院,湖北武汉430070

出　　处：《陶瓷学报》2024年第5期1031-1038,共8页Journal of Ceramics

基　　金：国家自然科学基金(11905164)。

摘　　要：三元锂陶瓷可作为聚变堆候选固态氚增殖材料。其中,硅酸锂(Li_(4)SiO_(4))锂密度较高,释氚性能良好。然而,Li_(4)SiO_(4)烧结较为困难,力学性能亟待改善。针对这一问题,研究提出通过中子倍增元素Pb、Zr添加的方式,调控陶瓷烧结特性及微细结构,以提高陶瓷致密度、改善机械性能。向前驱体溶液中以硝酸铅[Pb(NO_(3))_(2)]形式添加2 wt.%、5 wt.%和8 wt.%Pb元素,通过微波辅助溶液燃烧合成法得到陶瓷粉体。X射线衍射分析显示,陶瓷中Pb的有效成分为PbO。当向陶瓷中添加2 wt.%Pb元素后,陶瓷的致密度有所提高。在氧气氛围下,经1273 K烧结后相对致密度可达90%。对陶瓷的抗弯强度进行了测试,结果显示Pb添加可在一定程度上改善陶瓷的机械性能。因而,PbO虽然能够改善陶瓷的烧结致密化过程,但难以显著提高Li_(4)SiO_(4)的力学性能。向Li_(4)SiO_(4)添加10 wt.%ZrO_(2)后,Zr主要以Li_(2)ZrO_(3)形式存在。陶瓷晶粒得到明显细化,陶瓷的相对致密度为86.19%,其抗弯强度与致密度成正向关系。在此基础上,制备了Li_(4)SiO_(4)-10 wt.%ZrO_(2)微球,其抗压溃力可达40.76 N。Ternary lithium ceramics can be used as the solid candidate tritium breeding materials in fusion reactors.Lithium orthosilicate(Li_(4)SiO_(4))has fine tritium release performance owing to its relatively higher lithium density.However,the sintering of Li_(4)SiO_(4)is challenging.The mechanical properties need to be improved.In this study,neutron multiplier elements Pb and Zr were added to increase the ceramic density and improve the mechanical properties via the control of the sinterability and the microstructure.The lead(Pb)with the content of 2 wt.%,5 wt.%and 8 wt.%Pb was added into the precursor solution in the form of lead nitrate[Pb(NO_(3))_(2)].The ceramic powders were obtained by the microwave-induced solution combustion synthesis.The X-ray diffraction analysis shows that the effective phase was PbO.The ceramic density was increased by the addition of 2 wt.%Pb into ceramic.The relative density reached 90%by sintering at 1273 K under an oxygen atmosphere.The bending strength of the ceramics was tested.The results showed that the mechanical properties can be improved by Pb addition.Therefore,it is known that although PbO can improve the densification process of ceramics,the enhancement of mechanical properties is difficult.Zr mainly existed as Li_(2)ZrO_(3)after the introduction of 10 wt.%Zr in Li_(4)SiO_(4).The ceramic grains were refined obviously.The density of the ceramic reached 86.19%.The bending was related positively to the density.Further,the Li_(4)SiO_(4)-10 wt.%ZrO_(2)pebbles were fabricated.The crush load reached 40.76 N.

关 键 词：氚增殖剂 正硅酸锂 中子倍增元素 抗弯强度 抗压溃力 

分 类 号：TQ174.75[化学工程—陶瓷工业]