陶瓷隔热瓦轻量化制备

针对航天器减重的需求,开展了陶瓷隔热瓦轻量化制备研究。一方面不改变隔热瓦的组分和基本工艺参数,仅改变致密化程度得到较低密度(0.25～0.30 g/cm~3)的隔热瓦,研究其微观结构、热导率、力学性能和高温隔热效果随密度的变化规律;另一方面,改变隔热瓦的烧结温度或引入短纤维,分析参数改变对隔热瓦热导率和力学性能的影响。结果表明:密度减小会降低隔热瓦的室温热导率,同时力学性能及高温隔热效果也会下降;提高烧结温度是提高低密度隔热瓦力学性能的有效途径,不同长、短纤维比例对热导率和力学性能无明显影响。

Lightweighting Fabrication of Ceramic Insulating Tiles

To meet the lightweighting tendency of novel aerocrafts, ceramic insulating tiles with lower-density (0.25 to 0.30 g/cm³)were fabricated by adjusting densification degree, without changing the composition and primary processing parameters.The tiles'' microstructure, thermal conductivity, mechanical properties and high-temperature insulation performance were analyzed.In addition, the effects of sintering temperature and the ratio of long fibers to short fibers on the tiles'' thermal and mechanical properties were studied. The results show that the thermal conductivity decreases with decreasing density, while the mechanical properties and high-temperature insulation performance also decrease; increasing sintering temperature is an effective approach to improve the tiles'' mechanical properties for lower-density tiles, while the different ratios of long fibers to short fibers do not affect the tiles'' properties obviously.