Abstract SiC MgAl2O4 ceramic has a novel application for immobilizing radioactive graphite. The interface reaction between silicon and magnesium offers a significant challenge in the synthesis of SiC MgAl2O4 composites. In this paper, the effects of silicon source, magnesium source, sintering temperature and holding time on the interface reactivity were investigated by characterizing the phase compositions, microstructures, and hardness. The results show that the reactivity of silicon and magnesium varies with silicon sources and magnesium sources which also have a great effect on the microstructure of SiC MgAl2O4 composites. Either excessive sintering temperature or excessive holding time makes SiC MgAl2O4 composites decomposed into different phases, leading to a decreased hardness value. It is found that silicon as silicon source can contribute to the formation of SiC nanowires, which is in line with VS growth mechanism of SiC. The interface reactivity of element Si and Mg, which is positively correlated with high temperature and long holding time, has a negative effect on the phase compositions and performance of SiC MgAl2O4 ceramic by pressureless sintering.

中文翻译：

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硅镁反应活性对制备用于固定石墨的SiC MgAl2O4复合材料的影响

摘要 SiC MgAl2O4 陶瓷在固定放射性石墨方面具有新的应用前景。硅和镁之间的界面反应对 SiC MgAl2O4 复合材料的合成提出了重大挑战。在本文中，通过表征相组成、微观结构和硬度，研究了硅源、镁源、烧结温度和保温时间对界面反应性的影响。结果表明，硅和镁的反应活性随硅源和镁源的不同而变化，这对SiC MgAl2O4复合材料的微观结构也有很大影响。过高的烧结温度或过长的保温时间会使 SiC MgAl2O4 复合材料分解成不同的相，导致硬度值降低。发现硅作为硅源可以促进碳化硅纳米线的形成，这符合碳化硅的VS生长机制。与高温和长保温时间呈正相关的元素Si和Mg的界面反应性对无压烧结SiC MgAl2O4陶瓷的相组成和性能有负面影响。