Measurements of thermal conductivity and electrical conductivity of a single carbon fiber
Measurements of thermal conductivity and electrical conductivity of a single carbon fiber
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DOI：
10.1023/a:1006674510648
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发表时间：
2000-07-01
影响因子：
2.2
通讯作者：
Fujii, M
中科院分区：
文献类型：
--
作者：
Zhang, X;Fujiwara, S;Fujii, M
本文采用稳态短热丝法测量了不同制造条件下单根碳纤维的导热系数。该方法基于附接至短路的针翅片的传热现象。热线。短热丝通入恒定的直流电，产生均匀的热通量，其两端连接引线并保持在初始温度。测试光纤一端作为针翅固定在热线的中心位置，另一端连接到散热器。假设沿着热丝和测试纤维的一维稳态热传导，并解析求解基本方程。从这些解中，准确地得到了热丝的平均温升、发热率、光纤附着端的温度以及从热丝到光纤的热通量之间的关系。根据这些关系式，当测量同一系统的平均温升和热丝的生热率时，可以很容易地估算出单根碳纤维的热导率。此外，单根碳纤维的电导率是在与热导率相同的条件下使用四点接触法测量的。基于晶体微观结构，进一步讨论了热导率和电导率之间的关系。
In this paper, the thermal conductivity of a single carbon fiber under different manufacturing conditions is measured using the steady-state short-hot-wire method. This method is based on the heat transfer phenomena of a pin fin attached to a short. hot wire. The short hot wire is supplied with a constant direct current to generate a uniform heat flux, and both its ends are connected to lead wires and maintained at the initial temperature. The test fiber is attached as a pin fin to the center position of the hot wire at one end and the other end is connected to a heat sink. One-dimensional steady-state heat conduction along the hot wire and test fiber is assumed, and the basic equations are analytically solved. From the solutions, the relations among the average temperature rise of the hot wire, the heat generation rate, the temperature at the attached end of the fiber, and the heal flux from the hot wire to the fiber are accurately obtained. Based on the relations, the thermal conductivity of the single carbon fiber can be easily estimated when the average temperature rise and the heat generation rate of the hot wire are measured for the same system. Further, the electrical conductivity of the single carbon fiber is measured under the same conditions as for the thermal conductivity using a four-point contact method. The relation between the thermal conductivity and electrical conductivity is further discussed, based on the crystal microstructure.