DMREF/Collaborative Research: Accelerated Soft Magnetic Alloy Design and Synthesis Guided by Theory and Simulation

软磁材料用于电力转换、调节、配电和发电技术，包括交通运输(电动汽车)、可再生能源(太阳能逆变器)和航空航天(电力转换器和电感)部门。术语“软磁体”是指一种利用小磁场很容易改变磁极方向的磁性材料。由于美国超过20%的发电量被工业电机驱动所消耗，能源效率仅提高1%就会带来显著的财务和环境效益。在上述应用中，磁性部件是能量损失的主要来源，这促使对具有更高能效的软磁体的需求。到目前为止，新软磁材料的设计周期主要是由直接的人类工程直觉和历史知识和偏见决定的，材料开发是通过反复试验的方法进行的。这项旨在革新和设计我们的未来的设计材料奖(DMREF)支持建立、演示和验证计算指导框架的研究，以加速发现新的、性能更好的软磁材料。这种方法将使用计算材料科学工具来指导合金设计，并对向下选择的新合金进行性能合成和实验验证。最近，由非晶基质和纳米晶颗粒组成的微结构的新合金使先进的软磁材料发生了革命性的变化，实现了比传统磁性材料更小的磁滞。该奖项支持使用分级、多尺度、磁结构建模以及单晶结构和磁性的密度泛函理论计算的输入来设计这种类型的新合金的研究。微磁理论将为优化由纳米晶体周围的非晶基质组成的现实微结构的连续统级模型提供本构关系。连续介质水平的模拟代表了一项根本性的进步，它将提供所需的洞察，以确定微小的磁滞回线中微结构效应和晶相的磁性之间的相互作用，以及对当前流行的矫顽力的随机各向异性模型的适用范围的操作理解。结构方面的考虑将通过连续介质热力学建模进行评估，由此产生的磁性能特性将通过微磁学建模进行评估。向下选择的合金成分-通过这些计算方法进行优化-将使用快速凝固和随后的退火法合成，并使用最先进的结构和磁性表征工具进行表征。

Soft magnetic materials have use in power conversion, conditioning, distribution, and generation technologies, including transportation (electric vehicles), renewable energy (solar inverters), and aerospace (power converters and inductors) sectors. The term "soft magnet" refers to a magnetic material that easily changes magnetic pole directions using small magnetic fields. With over 20 percent of all generated electricity in the US being consumed by industrial electric motor drives, a mere 1 percent improvement in energy efficiency would result in significant financial and environmental benefits. The magnetic components are a major source of energy loss in the above-mentioned applications, motivating the need for soft magnets with better energy efficiency. The design cycle for new soft magnetic materials has so far been informed mainly by direct human engineering intuition and historic knowledge and bias, with materials development occurring by trial-and-error approaches. This Designing Materials to Revolutionize and Engineer our Future (DMREF) award supports research to establish, demonstrate, and validate a computation-guided framework for accelerated discovery of new, better performing soft magnetic materials. This approach will use computational materials science tools to guide alloy design, with the synthesis and experimental validation of properties performed for down-selected new alloys.Recently, new alloys with microstructures comprised of an amorphous matrix and nanocrystalline grains have revolutionized advanced soft magnetic materials by enabling smaller hysteresis than has been achieved in traditional magnetic materials. This award supports research on the design of new alloys of this type using hierarchical, multi-scale, magneto-structural modeling with input from density functional theory calculations of structural and magnetic properties for single-crystals. Micromagnetic theory will provide the constitutive law for the continuum-level model for optimization of realistic microstructures consisting of an amorphous matrix surrounding nanocrystals. The continuum-level modeling represents a fundamental advancement that will provide much-needed insight into the interplay between the microstructure effects and the magnetic properties of the crystalline phase in determining small hysteresis, as well as an operational understanding of the applicability limits of the currently-prevalent random anisotropy model for coercivity. Structural considerations will be evaluated by continuum thermodynamics modeling and resulting magnetic performance characteristics will be evaluated by micromagnetics modeling. Down-selected alloy compositions - as optimized by these computational approaches - will be synthesized using rapid solidification with subsequent annealing and characterized using state-of-the-art structural and magnetic characterization tools.