ABSTRACT With spalling and corrosion during thermal cycles, the castable composites used in injecting lance are easily damaged. In order to solve this problem, we used carbon fibers as additives in the matrix, and prepared mullite- based castables with the addition of anti-oxidant silicon. It was found that the addition of carbon fibers could significantly improve the mechanical properties; the maximum mechanical strength was obtained when 0.1 wt% carbon fibers was added, and the maximum thermal shock resistance was obtained when 0.2 wt% carbon fibers was added. The carbon fibers were oxidized mostly after firing at 1100oC, while after firing at 1450oC, due to the dense oxide layers generated on the surface of the castables, most of the carbon fibers in the castables remained in good combination with the matrix. Some SiC whiskers with SiO2 coating were formed in the matrix after heat treatment at 1100oC in air. The model of the whiskers growth mechanism followed the vapour-solid mechanism. GRAPHICAL ABSTRACT

中文翻译：

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碳纤维和原位晶须增强莫来石基浇注料复合材料的显微结构和性能

摘要 随着热循环过程中的剥落和腐蚀，用于注射枪的可浇注复合材料很容易损坏。为了解决这个问题，我们在基体中使用碳纤维作为添加剂，并添加了抗氧化硅制备了莫来石基浇注料。发现碳纤维的加入可以显着提高力学性能；加入0.1wt%碳纤维时机械强度最大，加入0.2wt%碳纤维时抗热震性最大。碳纤维在 1100oC 烧制后大部分被氧化，而在 1450oC 烧制后，由于浇注料表面产生致密的氧化层，浇注料中的大部分碳纤维与基体保持良好结合。在空气中 1100oC 热处理后，在基体中形成一些带有 SiO2 涂层的 SiC 晶须。晶须生长机制模型遵循气固机制。图形概要