EAGER: Properties and Manufacturing of Transformative Aluminum Nanocomposite Electrical Conductors

在美国，输电和配电损失平均约占每年输电和配电电力的6%。铝制架空电力电缆目前在电力传输和分配中占主导地位，大约100年来几乎没有改变。不断增长的电力需求造成了当前电网的拥堵。目前迫切需要一种新的方法来提高现有输电线路的容量。该奖项支持基础研究，以实现由纳米颗粒增强的变革性铝电导体的制造。这些导体可以在高工作温度限制下提供卓越的电力传输能力，并显著降低建设成本，提高未来输电网的可靠性。它们也可用于其他可再生能源和储能系统。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、尺寸、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。通过研究不同尺寸尺度下的电子传递，将建立电子散射的数学方程，并将用于预测铝纳米复合材料的电导率。标准的4点探针将用于测量含有0.1-10体积百分比的球形纳米颗粒（如TiB2）的铝导体的电导率，尺寸为5-60纳米。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颗粒（如TiB2、TiC和Ti5Si3）与熔融铝之间的相互作用势（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，同时使用无基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（抗拉强度、导热系数和热容）、微观结构（相、纳米颗粒分散、晶粒尺寸和形貌）和制造工艺参数之间的关系。铝纳米复合材料的凝固处理将由熔盐法辅助。纳米复合铸锭将被冷拉成钢丝。对纳米复合丝进行拉伸试验。采用激光闪蒸法和差示扫描量热法分别测量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射线衍射对纳米复合材料的微观结构进行了研究。

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.