Magnetostrictive Composites for Sensors and Actuators

信息和生物医学技术的巨大增长，加上现代运输系统的复杂性增加，促进了对具有更高性能、更高可靠性和更低成本的传感器和执行器的需求增加。磁致伸缩传感器/致动器已经变得越来越流行，并且可以在从汽车中的在线扭矩传感器到助听器中的声学换能器的各种应用中找到。然而，最受欢迎的磁致伸缩材料的单片形式容易出现几个技术问题，包括低拉伸强度、脆性断裂、高涡流损耗以及复杂和昂贵的制造。这些问题的一个解决方案是开发一种磁致伸缩复合材料传感器/致动器，其中磁致伸缩相的所需性质与基质相的所需性质相结合以产生高强度的复合材料，优异的加工性能和低涡流损耗。虽然已经进行了一些初步的尝试来开发磁致伸缩复合材料，但在几个关键领域中完成的工作很少。目前缺乏一个涵盖整个体积分数范围的综合实验数据库。 目前还没有一个全面的微观力学模型来设计磁致伸缩复合材料的特定性能目标。本研究项目将集中于产生一套完整的磁致伸缩（Terfenol-D）复合材料的磁力学实验数据，涵盖了整个体积分数范围。 实验数据，然后将被用于开发一个微机械模型的性能预测和设计的传感器/执行器。研究的最终目的是为磁致伸缩复合材料技术的工业应用提供科学和工程依据。从更广泛的角度来看，该研究项目通过解决进一步科学努力开发新的和更好的传感器和执行器的需要，解决了NSF和国家IT研究和开发的倡议。

Tremendous growth in information and biomedical technologies coupled with the increased complexity of modern transportation systems has fostered an increased demand for sensors and actuators with higher performance, enhanced reliability, and lower cost. Magnetostrictive sensors/actuators have become increasingly popular and can be found in a diverse set of applications ranging from on-line torque sensors in automobiles to acoustic transducers in hearing aids. Yet, monolithic versions of the most popular magnetostrictives are prone to several technical problems including low tensile strength, brittle fracture, high eddy current losses, and complex and costly manufacturing.One solution to these problems is to develop a magnetostrictive composite sensor/actuator in which the desirable properties of the magnetostrictive phase are combined with those of the matrix phase to create a composite of high strength, excellent processability, and low eddy current losses. Although some initial attempts have been undertaken to develop magnetostrictive composites, very little work has been accomplished in several key areas. A comprehensive experimental database spanning the full range of volume fraction is currently lacking. No comprehensive micromechanical model has emerged to design magnetostrictive composites for specific performance targets.This research project will focus on generating a complete set of magnetomechanical experimental data spanning the full range of volume fraction for magnetostrictive (Terfenol-D) composites. The experimental data will then be utilized in developing a micromechanical model for performance prediction and design of sensors/actuators. The ultimate aim of the research is to provide the scientific and engineering basis for industrial application of magnetostrictive composites technology. From a broader perspective this research project addresses the NSF and national initiative for IT research and development by addressing the need for further scientific efforts in developing new and better sensors and actuators.