EAGER: Properties and Manufacturing of Transformative Aluminum Nanocomposite Electrical Conductors

输电和配电损耗平均约占美国每年输电和配电电量的6%。铝制架空电缆目前在输电和配电中占主导地位，大约100年来几乎没有变化。不断增长的电力需求造成了当前电网的拥堵。迫切需要一种新的方式来增加现有传输线的容量。该奖项支持基础研究，使纳米颗粒增强的变革性铝电导体的制造成为可能。这些导线可以在较高的运行温度限制下提供卓越的输电能力，并显著降低建设成本并提高未来电网的可靠性。它们还可以用于其他可再生能源和能量储存系统。第一个研究目标是建立均匀分散在铝衬底上的纳米粒子的电子散射效应与纳米粒子的材料类型、大小、形状和体积百分比之间的关系。为了实现这一目标，将进行理论和实验研究。通过考察不同尺度下的电子输运，建立了纳米颗粒电子散射的数学方程，并将其用于预测铝纳米复合材料的电导率。标准的四点探头将被用来测量含有0.1-10%体积分数的球形纳米粒子(如TiB2)的铝导体的电导率，尺寸为5-60 nm。电导率的一些预测值将与实测值进行比较。第二个研究目标是确定纳米粒子(如TiB2、TiC和Ti5Si3)与铝熔体之间的相互作用势(界面能、范德华势和热能)。为了实现这一目标，将建立基于分子间相互作用的分析模型，同时将使用座滴法和原子力显微镜进行实验测量。第三个研究目标是建立铝纳米复合材料的性能(拉伸强度、导热系数和热容)、微观结构(物相、纳米颗粒分散度以及颗粒的大小和形态)和制造工艺参数之间的关系。熔盐法将辅助铝纳米复合材料的凝固过程。纳米复合钢锭将被冷拉成金属丝。将对纳米复合线进行拉伸测试。用激光闪光法和差示扫描量热法分别测量了纳米复合材料的导热系数和热容。利用光学显微镜、电子显微镜和X射线衍射仪对纳米复合材料的微观结构进行了分析。

Electricity transmission and distribution losses average about 6 percent of the electricity that is transmitted and distributed annually in the United States. The aluminum overhead power cables, currently dominant for electricity transmission and distribution, have remained almost unchanged for roughly 100 years. The ever increasing demand for electric power has created congestion on the current power grid. There is an urgent need for a new way of increasing the capacity of current transmission lines. This award supports fundamental research to enable manufacturing of transformative aluminum electrical conductors enhanced by nanoparticles. These conductors can offer superior power transmission capacity with a high operating temperature limit, and significantly reduce construction costs and increase reliability of future power transmission grids. They can also be used for other renewable energy and energy storage systems. The first research objective is to establish relationships between electron scattering effects of nanoparticles uniformly dispersed in aluminum substrates and the material type, size, shape, and volume percentage of the nanoparticles. To achieve this objective, both theoretical and experimental studies will be conducted. Mathematical equations of electron scattering by nanoparticles will be developed by examining electron transport at different size scales, and will be used to predict electrical conductivity of aluminum nanocomposites. A standard 4-point probe will be used to measure the electrical conductivity of aluminum conductors containing 0.1-10 vol percent spherical nanoparticles (such as TiB2) with a size of 5-60 nm. Some predicted values of electrical conductivity will be compared against measured values. The second research objective is to determine the interaction potentials (interfacial energy, van der Waals potential, and thermal energy) among nanoparticles (such as TiB2, TiC, and Ti5Si3) and molten aluminum. To achieve this objective, analytical models based on intermolecular interactions will be established while experimental measurements will be carried out using the sessile-drop method and atomic force microscope. The third research objective is to establish relationships among properties (tensile strength, thermal conductivity, and heat capacity), microstructure (phase, nanoparticle dispersion, and size and morphology of grains), and manufacturing process parameters for aluminum nanocomposites. Solidification processing of aluminum nanocomposites will be assisted by a molten salt method. Nanocomposite ingots will be cold drawn into wires. Tensile testing on the nanocomposite wires will be conducted. Thermal conductivity and heat capacity of the nanocomposite will be measured using the laser flash method and differential scanning calorimetry, respectively. Microstructure of the nanocomposites will be examined by optical and electron microscopes and X-ray diffraction.