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

软磁材料可用于电力转换、调节、配电和发电技术，包括运输（电动汽车）、可再生能源（太阳能逆变器）和航空航天（电力转换器和电感器）领域。术语“软磁体”是指使用小磁场容易改变磁极方向的磁性材料。在美国，超过20%的发电量被工业电机驱动消耗，能源效率仅提高1%就能带来巨大的经济和环境效益。在上述应用中，磁性部件是能量损失的主要来源，从而激发了对具有更好能量效率的软磁体的需求。到目前为止，新软磁材料的设计周期主要是由人类工程直觉和历史知识和偏见所告知的，材料开发是通过试错法进行的。设计材料以革命和工程我们的未来（DMREF）奖支持研究建立，演示和验证计算指导的框架，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，并对精选的新合金进行合成和性能实验验证。最近，具有非晶基体和纳米晶晶粒组成的微结构的新合金通过实现比传统磁性材料更小的磁滞，彻底改变了先进的软磁材料。该奖项支持使用分层，多尺度，磁结构建模与单晶结构和磁性的密度泛函理论计算输入的新型合金的设计研究。微磁学理论将提供连续水平模型的本构关系，用于优化由纳米晶体周围的非晶基体组成的实际微结构。连续级建模代表了一个根本性的进步，将提供急需的洞察到的微观结构的影响和磁性能的结晶相之间的相互作用，在确定小滞后，以及操作的理解，目前流行的随机各向异性模型的适用性限制的结晶度。结构考虑将通过连续热力学建模进行评估，并且由此产生的磁性能特性将通过微磁学建模进行评估。通过这些计算方法优化的向下选择的合金成分将使用快速凝固和随后的退火来合成，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.