纤维和遮光剂对纳米孔粉体隔热材料性能的影响

新型高温隔热材料对工业窑炉高效节能作用显著,降低其高温辐射导热率有利于提高高温隔热性能。采用干压成型制备了添加不同种类和不同含量的纤维及遮光剂的纳米孔粉体隔热材料,分别测试了试样的常温耐压强度和不同温度下的导热系数,探讨了纤维和遮光剂对纳米孔粉体隔热材料的力学性能和隔热性能的影响,并利用SEM、EDS和FTIR对试样的微观结构和红外透射率进行了分析表征。结果表明,多晶莫来石纤维有效增强了纳米孔粉体隔热材料的耐压强度,掺杂9%(质量分数)多晶莫来石纤维试样在800 ℃的导热系数为0.047 W/(m·K),低于添加石英纤维的隔热材料;纳米SiC粉体和锆英石粉体作为遮光剂能够有效抑制辐射传热,降低高温辐射热导率,添加10%(质量分数)纳米SiC粉体遮光剂的隔热材料试样导热系数随温度的变化较小,在800 ℃仅为0.041 W/(m·K)。

Effects of Fibers and Opacifiers on Properties of Nanoporous Powder Insulation Material

Novel high temperature insulation material has a significant energy efficient effect on the industrial kiln, and it reduces the kiln high temperature radiation thermal conductivity facilitating high temperature insulation performance. In this work, the samples of fibers and opacifiers to add different types and different mass fraction were prepared using a dry method and the compressive strength and thermal conductivity of the samples were tested, and the microstructure and infrared transmittance of the samples were analyzed by SEM, EDS and FTIR. The results show that polycrystalline mullite fiber effectively improves the compressive strength of the insulation material and the thermal conductivity of the 9% (mass fraction) polycrystalline mullite fiber doped the nanoporous powder insulation material is 0.047 W/(m·K) at 800 ℃, which is lower than that of the insulation material added with quartz fiber. Nano-SiC powder and zircon powder effectively inhibit the radiant heat transfer and reduce the high-temperature radiant thermal conductivity as the opacifier. The thermal conductivity of the nanoporous powder insulation material with 10% (mass fraction) nano-SiC powder added is only 0.041 W/(m·K) at 800 ℃.