Compact nanocrystalline soft magnets using Field-Assisted Sintering

该应用转移项目基于DFG成功完成的优先计划SPP 1959项目，该项目研究了场辅助烧结技术（FAST/SPS）过程中温度分布和晶粒生长的模拟。在已完成的项目中获得的专有技术将转移到应用项目的工业应用中。该项目将从技术准备水平（TRL）4开始。所建立的数值模型将为纳米晶软磁材料的应用领域的进一步发展奠定基础。在此转移项目中，FAST/SPS将用于加工紧凑型纳米晶软磁材料（Finemet Fe73.5Cu1Nb3Si15.5B7（at.%））以便生产具有几何多样性、高功率密度和低磁滞和涡流损耗的软磁部件。紧凑的设计使商业卷芯的典型塑料外壳变得不必要，从而允许组件在高达300°C而不是150°C的温度下运行。这些改进目前在软磁领域的小型化和有效的能量转换方面具有非凡的意义。压实的材料应该能够根据其磁导率制造成不同的电感元件，从而使广泛的应用成为可能。初步研究表明，由熔融纺丝带制成的非晶薄片的加工可以帮助实现产品的有前途的性能，因为可以通过选择合适的薄片尺寸来直接调节软磁性能。然而，具有不同尺寸分布的薄片可能导致在压实过程中完全不同的温度分布，这导致不均匀的微观结构。因此，为了确保在所需的温度窗口内均匀的温度分布，数值模拟是必要的。从已完成的DFG项目中获得的知识和开发的方法为紧凑型纳米晶软磁元件的加工和该转移项目的工业应用提供了坚实的基础。通过进一步开发的模型，FAST/SPS期间温度分布均匀化和软磁材料压实的概念性想法将在虚拟迭代仿真回路中进行测试，并随后应用于演示器的制造。通过这种方式，可以用节省时间、资源和成本的简单程序取代目前广泛采用的试错法。

This applied transfer project is based on a successfully completed DFG project with the Priority Programme SPP 1959, which studied the simulation of temperature distribution and grain growth during field-assisted sintering technology (FAST/SPS). The know-how obtained in the completed project will be transferred to an industrial application in the applied project. This project will start at technology readiness level (TRL) 4. The developed numerical model will be the fundamental basis for further developments in the application-oriented field of manufacturing compact nanocrystalline soft magnets. In this transfer project, FAST/SPS will be used for the processing of compact nanocrystalline soft magnets (Finemet Fe73.5Cu1Nb3Si15.5B7 (at.%)) in order to produce soft magnetic components with geometric diversity, high power density, and low hysteresis and eddy current losses. The compact design makes the typical plastic housing of the commercial wounded cores unnecessary which allows the operation of the components at up to 300°C, instead of 150°C. These improvements are currently of extraordinary interest for the miniaturization and the efficient energy conversion in the field of soft magnets. The compacted materials should be able to be manufactured into different inductive components depending on their magnetic permeabilities, so that a wide range of applications is possible. Preliminary investigations showed that the processing of amorphous flakes made from melt spun ribbons could help to achieve promising properties of the products, as the soft magnetic properties can be directly adjusted by selecting suitable flake sizes for manufacturing. However, the flakes with different size distributions could lead to completely different temperature distributions in the compaction process, which results in inhomogeneous microstructures. Therefore, to assure a homogenous temperature distribution within the required temperature window, the numerical simulation is necessary. The gained knowledge and the developed methods from the completed DFG project provide a solid basis for the processing of compact nanocrystalline soft magnetic components and the industrial application in this transfer project. With the further developed models, the conceptual ideas for the homogenization of the temperature distribution and the compaction of soft magnetic material during FAST/SPS will be tested in virtual, iterative simulation loops, and subsequently applied in the manufacture of the demonstrator. In this way, the currently well-employed trial and error methodology can be replaced by a straightforward procedure which saves time, recourses and cost.