Abstract Fly ash cenosphere/mullite (FACs/M) composites with excellent high-temperature resistance were prepared through a tert-butyl alcohol gelcasting process, using the mullite and FACs as the matrix and the filler, respectively, and the matrix of mullite was derived from phase transformation of the raw material of kaolin. Results show that the FACs/M exhibited low density and high specific compressive strength and the thermal conductivity was distributed over in the range of values predicted from Maxwell-Eucken model 2 and Effective Medium Theory (EMT) equation. Exponent m describing the relationship between compressive strength and porosity was 2.37. Young’s moduli of the composites were lower than that predicted from the Hashin-Shtrikman model. The high-temperature testing results revealed that the FACs/M composite exhibited high compressive strength and the 50% FACs/M composite displayed compressive strength of 14.11 MPa after testing at 800 °C. The FACs/M composites with excellent mechanical properties both at room and high temperatures may possibly be used in the deep sea and other fields in the near future.

中文翻译：

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高温用粉煤灰微珠/莫来石复合材料的制备及特性

摘要 以莫来石和FACs分别为基体和填料，通过叔丁醇凝胶注模工艺制备了具有优异耐高温性能的粉煤灰空心微珠/莫来石(FACs/M)复合材料，得到了莫来石基体。来自高岭土原料的相变。结果表明，FACs/M 表现出低密度和高比压强度，并且热导率分布在根据 Maxwell-Eucken 模型 2 和有效介质理论 (EMT) 方程预测的值范围内。描述抗压强度和孔隙率之间关系的指数 m 是 2.37。复合材料的杨氏模量低于 Hashin-Shtrikman 模型的预测值。高温测试结果表明，FACs/M 复合材料表现出较高的抗压强度，50% FACs/M 复合材料在 800 °C 下测试后的抗压强度为 14.11 MPa。FACs/M复合材料在室温和高温下均具有优异的力学性能，在不久的将来有可能用于深海等领域。