Soft magnetic composites play a pivotal role in enhancing the efficiency of new energy vehicles. However, balancing their permeability and energy loss during material design remains a key challenge. This study introduces an innovative strategy for developing FeSiAl soft magnetic composites by integrating interfacial reaction engineering with magnetic field–oriented moulding. Optimising the NaOH used in the composite preparation enables precise control over the interfacial reaction process, facilitating the formation of uniform Al₂O₃ insulation layers along both the in-plane and thickness directions of the flake-shaped FeSiAl particles. Using NaOH promotes the surface migration and oxidation of aluminium, inducing the growth of Al₂O₃ layers through a synergistic interplay of chemical reactions and surface diffusion. Uniform Al₂O₃ layers are obtained by enhancing the surface diffusion via high-temperature calcination, balanced interfacial chemical reaction and comprehensive regulation of the nucleation energy. When the optimal NaOH amount (6 wt%) is used, the FeSiAl/Al₂O₃ composites exhibit exceptional magnetic properties (resistivity = 331.1 Ω·m, total core loss =112.78 kW/m³, saturation magnetisation = 149.3 emu/g, effective permeability = 135.78 at 1 MHz and quality factor = 88.6), considerably surpassing traditional composites derived from spherical or flake-shaped particles. This approach combining interfacial reaction engineering and magnetic field orientation effectively addresses the trade-off problem between permeability and core loss, providing a robust framework for designing high-performance soft magnetic materials suitable for next-generation drive motors.

中文翻译：

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用于平衡 FeSiAl 软磁复合材料磁导率和磁芯损耗的界面反应工程和磁场导向优化

软磁复合材料在提高新能源汽车的效率方面发挥着举足轻重的作用。然而，在材料设计过程中平衡它们的磁导率和能量损失仍然是一个关键挑战。本研究介绍了一种通过将界面反应工程与磁场定向成型相结合来开发 FeSiAl 软磁复合材料的创新策略。优化复合材料制备中使用的 NaOH 可以精确控制界面反应过程，促进沿片状 FeSiAl 颗粒的面内和厚度方向形成均匀的 Al ₂ O ₃ 绝缘层。使用 NaOH 可促进铝的表面迁移和氧化，通过化学反应和表面扩散的协同相互作用诱导 Al ₂ O ₃ 层的生长。通过高温煅烧增强表面扩散、平衡界面化学反应和综合调节成核能，获得均匀的 Al ₂ O ₃ 层。当使用最佳 NaOH 量 （6 wt%） 时，FeSiAl/Al ₂ O ₃ 复合材料表现出优异的磁性（电阻率 = 331.1 Ω·m，总磁芯损耗 = 112.78 kW/m ³ ，饱和磁化 = 149.3 emu/g，1 MHz 时有效磁导率 = 135.78，品质因数 = 88.6），大大超过了球形或片状颗粒的传统复合材料。这种方法结合了界面反应工程和磁场取向，有效地解决了磁导率和磁芯损耗之间的权衡问题，为设计适用于下一代驱动电机的高性能软磁材料提供了强大的框架。