闪光法测试压缩膨胀石墨热导率探讨

Flash method for determining the thermal conductivity of compacted exfoliated graphite

闪光法是广泛使用的测量材料的热扩散系数的方法。压缩膨胀石墨是具有各向异性的一种高导热复合材料。理论上闪光法并不适用于测试复合材料的热导率,但在实际的研究工作中该方法被广泛采用。本研究用闪光法测试了不同厚度和密度的压缩膨胀石墨,使用单因素方差分析,发现在实验的范围内样品厚度对其测量数据并无显著影响。结合复合材料的结构特点,认为闪光法可用于压缩膨胀石墨的热导率测试。同时也发现密度对压缩膨胀石墨导热性影响显著。

Compacted exfoliated graphite（CEG） is a kind of anisotropic composite composed of graphite nano-platelets（GNPs） and air.Theoretically,the flash method,a widely used test method for thermal diffusivity,could not be used in measuring the thermal conductivity of the composite materials.The influences of thickness and density on the thermal conductivity of CEG by the flash method were studied in this paper.It was found that the thickness of CEG had little impacted to the thermal conductivity,then flash method could be applied to determining the thermal conductivity of heterogeneous composite like CEG,and it was also found that the thermal conductivity increased with increasing of density.