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、分配和发电技术，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（电力转换器和电感器）部门。“软磁铁”一词指的是一种磁性材料，它可以用很小的磁场轻易地改变磁极的方向。在美国，超过20%的电力是由工业电机驱动消耗的，仅仅提高1%的能源效率就会带来巨大的经济和环境效益。磁性元件是上述应用中能量损失的主要来源，因此需要具有更好能量效率的软磁体。到目前为止，新型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，材料的开发是通过试错方法进行的。该设计材料革新和工程我们的未来（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，并对选定的新合金进行性能的合成和实验验证。最近，由非晶基体和纳米晶颗粒组成的新型合金的微结构使其具有比传统磁性材料更小的磁滞，从而彻底改变了先进的软磁材料。该奖项支持使用分层、多尺度、磁结构建模和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。微磁理论将提供连续级模型的本构律，以优化由纳米晶体周围的非晶基质组成的实际微结构。连续水平的建模代表了一个根本性的进步，它将为微观结构效应和晶体相的磁性之间的相互作用提供急需的洞察力，以确定小的磁滞，以及对当前流行的随机各向异性矫顽力模型的适用性限制的操作理解。结构方面的考虑将通过连续体热力学建模来评估，而产生的磁性性能特征将通过微磁建模来评估。通过这些计算方法优化的选定合金成分将通过快速凝固和随后的退火合成，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.