EAGER: Novel Nitride-Based Exchange-Spring Nanocomposites

新型氮基交换弹簧磁性纳米复合材料技术：随着电力需求的不断升级，人们越来越重视生产高功率密度的电机，用于电机、发电机、致动器等。一项很有前途的新技术是使用交换弹簧永磁体（ESPM）来生产这些功率密集的机器。espm是磁性硬的？和软?交换耦合产生高能量产物的相（BH）max。据报道，快速凝固、熔融纺丝和球磨稀土过渡金属（RE-TM）金属间espm具有较高的BH最大值。此外，氮基espm是永磁体的有希望的候选者，其性能可能超过NdFeB-Fe RE-TM espm。本文研究了一种新的低温合成技术，用于制备具有高BH最大值和工作温度的氮基纳米复合材料。该合成技术是基于硬磁相纳米粉末与软相层合，硬相和软相催化氮化，并使用脉冲等离子体压实低温致密化。这种方法将提供更好的晶粒尺寸控制和硬相和软相之间的交换耦合，更低的氮化相合成温度，更低的温度压实和更强的耐腐蚀性。PI打算探索这些新型氮基纳米复合材料的合成，了解它们的性质并优化它们的成分以获得高能产物永磁体。这项工作的高回报源于纳米复合材料中软铁相的低温催化氮化。如果成功，这项研究将产生两个重要的突破，一个是氮基复合材料合成的新途径，另一个是使用高能产品永磁体开发更节能、更紧凑的设备的具体指导。非技术：该项目是一项很有前途的新技术，用于生产用于功率密集机器的氮基交换耦合永磁体。这种方法从当前的、定义不清的纳米尺度形态转向空间和组合工程纳米结构。这种新颖的设计方法通过利用材料的磁晶和形状各向异性，提供了以前无法实现的磁性。这项研究提供了工艺上的突破和基本的理解，这将促进未来新型高性能永磁体的商业发展。研究工作与一项旨在向研究生和本科生教授研究方法的教育倡议相结合。

Novel Nitride-Based Exchange-Spring Magnetic NanocompositesTECHNICAL: With escalating power demands, there is an increased emphasis on producing high power density electrical machines for use as motors, generators, actuators, etc. A promising new technology to produce these power-dense machines employs exchange spring permanent magnets (ESPM). ESPMs are magnetically ?hard? and ?soft? phases that are exchange-coupled to give high energy products, (BH)max. High (BH)max values have been reported for rapidly-solidified, melt-spun, and ball-milled rare-earth-transition metal (RE-TM) intermetallic ESPMs. In addition nitride-based ESPMs are promising candidates for permanent magnets whose performance could exceed that of the NdFeB-Fe RE-TM ESPMs. In this research a novel low-temperature synthesis technique is examined for fabricating nitride-based nanocomposites with high (BH)max values and operating temperatures. This synthesis technique is based on laminating hard magnetic phase nanopowders with soft phases, catalytic nitrogenation of the hard and soft phases, and low temperature densification using pulse plasma compaction. This approach should provide greater grain size control and exchange-coupling between the hard and soft phases, lower temperature synthesis of the nitride phases, lower temperature compaction, and greater corrosion resistance. The PI intends to explore the synthesis of these novel nitride-based nanocomposites, to understand their properties and to optimize their compositions to obtain high energy product permanent magnets. The high payoff of this work derives from the low temperature catalytic nitrogenation of the soft iron phase in the nanocomposites. If successful, this study will yield two important breakthroughs, a new avenue for the synthesis of nitride-based composite materials and specific guidance for developing more energy efficient, compact devices using high energy product permanent magnets. NONTECHNICAL: This project is a promising new technology for the production of nitride-based exchange-coupled permanent magnets for power-dense machines. This approach moves away from current, poorly-defined, nanoscale morphologies to spatially and compositionally engineered nanostructures. This novel design approach offers previously unattainable magnetic properties by exploiting magnetocrystalline and shape anisotropy of materials. The research provides processing breakthroughs and fundamental understanding that should facilitate future commercial development of a new class of high performance permanent magnets. The research effort is coupled to an educational initiative aimed at teaching research methodology to graduate and undergraduate students.