Thermophysical properties of carbon/carbon composites and physical mechanism of thermal expansion and thermal conductivity
Thermophysical properties of carbon/carbon composites and physical mechanism of thermal expansion and thermal conductivity
复制标题
DOI：
10.1016/j.carbon.2004.06.024
复制
发表时间：
2004-01-01
期刊：
影响因子：
10.9
通讯作者：
Tian, GL
中科院分区：
文献类型：
--
作者：
Luo, RY;Liu, T;Tian, GL
制备了5种不同的C/C复合材料，并对其热物理性能进行了研究。这是三种不同微观结构的热解碳（PyC）浸渍的针刺碳毡、短切纤维/树脂碳+ PyC和碳布/PyC。结果表明，在0-100 ℃范围内，X-Y方向的热膨胀系数（CTE）为负值，范围为-0.29 ~-0.85 × 10 ~（-6）/K。在0- 900 ℃范围内，它们的热膨胀系数也很低，热膨胀系数-温度曲线的斜率几乎相同。在相同的温度范围内，使用短切纤维制备的复合材料显示出最小的CTE值，而使用毡制备的复合材料显示出最高的CTE值。对于具有相同预制体结构的复合材料，热解炭的微观结构对热膨胀系数没有明显影响。其膨胀主要是由原子振动、孔隙收缩和水分挥发引起的。然而，PyC结构对热导率（TC）有很大的影响，粗糙层状PyC给出最高值，各向同性PyC给出最低值。所有五种复合材料都具有高的TC，并且X-Y方向上的值（25.6-174 W/mK）远大于Z方向上的值（3.5-50 W/mK）。这些复合材料中的热传递是通过声子相互作用，并与预制体和PyC结构有关。(C)2004 Elsevier Ltd.保留所有权利。
Five different carbon/carbon composites (C/C) have been prepared and their thermophysical properties studied. These were three needled carbon felts impregnated with pyrocarbons (PyC) of different microstructures, chopped fibers/resin carbon + PyC, and carbon cloth/PyC. The results show that the X-Y direction thermal expansion coefficient (CTE) is negative in the range 0-100 degreesC with values ranging from -0.29 to -0.85 x 10(-6)/K. In the range 0-900degreesC, their CTE is also very low, and the CTE vs. T curves have almost the same slope. In the same temperature range composites prepared using chopped fibers show the smallest CTE values and those using the felts show the highest. The microstructure of the PyC has no obvious effect on the CTE for composites with the same preform architecture. Their expansion is mainly caused by atomic vibration, pore shrinkage and volatilization of water. However, the PyC structure has a large effect on thermal conductivity (TC) with rough laminar PyC giving the highest value and isotropic PyC giving the lowest. All five composites have a high TC, and values in the X-Y direction (25.6-174 W/mK) are much larger than in the Z direction (3.5-50 W/m K). Heat transmission in these composites is by phonon interaction and is related to the preform and PyC structures. (C) 2004 Elsevier Ltd. All rights reserved.