摘要微纳米线材具有优异的性能，在微纳电子器件、能源转换、航天航空、生物医学等 领域中有着广泛的应用。微纳米材料的热物性对系统的热设计起到重要作用。由于微米 线特征尺寸极小，宏观尺度下测量材料热物理性能的方法在微纳米尺度下不再适用。本 文利用的 T 形法能够测量导电和非导电微纳米线材的热导率，是目前能有效测量单根碳 纳米管热导率的仅有的几种方法之一。

本文的主要内容是利用 T 形法测量微米线材的热输运性质，为新型微米线材热输运 特性的评价提供依据。原理方面，本文回顾了 T 形法的测量原理，分析了热辐射、节点 位置以及接触热阻对测量结果的影响规律。实验方面，本文先用直流通电法对白金线（热 线）的热学性质进行了标定，然后用 T 形法测量了标准物质（白金线）的热导率并与参 考值比较，验证了该方法的可行性，在此基础上对单根碳纤维的热输运性质进行了测量。 实验结果表明直径为 45 μm 的单根 PVA 纤维在 303 K 时的热导率为 66。1 W/(m·K)，直径 为 15。9 μm 的石墨化碳纤维在 350 K 时的热导率为 425 W/(m·K)。误差分析表明测量结果 的不确定度小于 10%。79976

毕业论文关键词 T 形法 微米线材 热导率

Title Measurement of Thermal Conductivity of Microwires by T Type Method

Abstract Micro/nanowires have wide applications in areas such as micro/nano electric devices, energy conversation, aerospace, detection, biomedicine and so on because of its excellent properties。 The thermal physical properties of micro/nanowires are very important for the thermal design of system。 Because of the micro/nanostructure, the thermometry applied in the macroscale can no longer meet the requirement of the measurement of the micro/nanowires。 The T type probe used in this paper can be used to measure the thermal conductivity of conductive and non-conductive filament materials。 It’s one of the several methods that can effectively measure the thermal conductivity of single carbon nanotube at present。 The main content of this paper is using the T type probe to measure thermal transport properties of micro/nanowires，and provides the reference for the thermal transport properties of new microwire。 In the part of principle, we review the measurement principle of T type probe, and concern the radiation, the positions of the junction, thermal contact resistance when measuring the thermal conductivity。 In the part of experiments, we first using direct current heating method to measure the thermal conductivity of the hot wire, and then use the T type probe to measure the thermal transport properties of the carbon fiber。 The experiment results show that the thermal conductivity of inpidual PVA fiber with the diameter of 45 μm is 66。1 W/(m·K) when the temperature is 303 K, and the thermal conductivity of inpidual carbon fiber with the diameter of 15。9 μm is 425 W/(m·K) when the temperature is 350 K。The uncertainty of the experimental results is less