NSF/DOE Thermoelectrics Partnership:Collaborative Proposal: Integration of Advanced Materials, Interfaces, and Heat Transfer Augmentation Methods for Affordable and Durable Devices

这项提案涉及回收废气余热，以提高车辆的使用效率。一个由机械工程师、材料科学家和化学家组成的跨学科团队被聚集在一起，通过合成具有改进的热电优值的新型纳米结构硅化物来解决这个问题。智能优点：拟议的纳米复合材料和相关界面的研究将有助于为承受热循环和振动的热电系统进行稳健和灵活的热机械设计奠定科学和工程基础。PI将使用具有各向同性负热膨胀(NTE)的填充材料来开发具有可调节热膨胀系数(CTE)的金属基复合材料。在不显著降低导电性和导热性的情况下，填充材料如ZrW2O8粉末可以有效地抵消金属相较高的热膨胀系数。这些纳米复合材料可用作电极或界面层，用于制造分段热电元件。将开发TE模块的热机械模型来指导纳米复合材料的设计，包括那些具有功能梯度组成的纳米复合材料。将合成基于不同金属如银、铝和镍的纳米复合材料，并对其热性能和热机械性能进行实验表征。还将开发与TE材料产生可靠的电、热和机械结合的方法。广泛影响：拟议的研究旨在最大限度地扩大在汽车尾气热回收和其他相关工程应用中大规模实施的潜力。将开发的新材料合成和键合方法被认为有助于经济地制造耐用TE器件。该计划包括的另一个组成部分是对学生进行跨学科研究的培训，使基础科学与先进工程相结合。PI和研究生将参加外展项目，通过加州大学洛杉矶分校举办的暑期研究项目将科学和工程带给K-12年级的学生。

1048726JuThis proposal is concerned with recovering exhaust waste heat to improve the efficiency of vehicles. An interdisciplinary team of mechanical engineers, a material scientist, and a chemist is assembled to tackle this problem by synthesizing novel nanostructured silicides with improved thermoelectric figures of merit. Intellectual Merit: The proposed research on nanocomposites and related interfaces will help establish a scientific and engineering foundation for robust and flexible thermomechanical design of thermoelectric systems subjected to thermal cycling and vibration. The PIs will develop metal-matrix composites with tailorable coefficients of thermal exapansion (CTEs) using a filler material with an isotropic negative thermal expansion (NTE). NTE fillers, such as ZrW2O8 powders, can effectively offset the high CTE of the metal phase without significantly degrading the electrical and thermal conductivity. These nanocomposites may be used as electrodes or as interfacial layers for creating segmented thermoeletric elements. Thermomechanical models of TE modules will be developed to guide the design of the nanocomposites, including those with functionally graded compositions. Nanocomposites based on different metals, such as Ag, Al, and Ni, will be synthesized and their thermal and thermomechanical properties will be experimentally characterized. Methods to produce reliable electrical, thermal, and mechanical bonds with TE materials will also be developed.Broader Impact: The proposed research is designed to maximize the potential for large-scale implementation in vehicle exhaust heat recovery and other related engineering applications. The new material synthesis and bonding methods that will be developed is considered to facilitate economic fabrication of durable TE devices. Another component included in the plan is the training of students in interdisciplinary research whereby fundamental science is coupled to advanced engineering. The PI and graduate students will participate in outreach programs to bring science and engineering to pupils in grades K-12 through summer research programs hosted at UCLA.