Compact nanocrystalline soft magnets using Field-Assisted Sintering

这个应用转移项目是基于1959年SPP优先计划成功完成的DFG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。在完成的项目中获得的专有技术将在申请项目中转移到工业应用中。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体制造应用领域的进一步发展奠定基础。在这个转移项目中，FAST/SPS将用于加工紧凑的纳米晶软磁体（Finemet Fe73.5Cu1Nb3Si15.5B7 (at.%)），以生产具有几何多样性、高功率密度、低磁滞和涡流损耗的软磁元件。紧凑的设计使得典型的商业损伤核心的塑料外壳不必要，允许组件在高达300°C的操作，而不是150°C。这些改进对于软磁领域的微型化和高效能量转换具有重要意义。压实的材料应该能够根据其磁导率制成不同的电感元件，以便有广泛的应用。初步研究表明，通过选择合适的薄片尺寸，可以直接调节产品的软磁性能，从而制备出具有良好性能的非晶态薄片。然而，不同尺寸分布的薄片会导致压实过程中完全不同的温度分布，从而导致微观结构不均匀。因此，为了保证所需温度窗内温度分布均匀，有必要进行数值模拟。通过完成DFG项目所获得的知识和开发的方法，为本转移项目中致密纳米晶软磁元件的加工和工业应用提供了坚实的基础。随着进一步开发的模型，在FAST/SPS过程中温度分布均匀化和软磁材料压实的概念将在虚拟迭代仿真循环中进行测试，并随后应用于演示器的制造。这样，目前广泛采用的试错法就可以被一种直接的程序所取代，从而节省时间、资源和费用。

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.