高Bs纳米晶软磁合金在退火得到非晶/纳米晶双相复合结构后，软磁性能优化的同时都不可避免的呈现弯折脆性，这成为该类材料在节能高效电机等高端领域应用推广所面临的瓶颈问题。本项目拟以高Fe浓度Fe-Si-B-P-C-Cu系合金为对象，在我们前期工作的基础上，研究微量过渡金属添加和类金属元素的配比调节对合金的热稳定性、非晶形成能力、软磁性能和弯折韧性的影响规律，澄清合金元素影响其热稳定性和非晶形成能力的机制。系统研究不同合金元素对 Fe-Si-B-P-C-Cu非晶晶化行为的影响，结合结构表征及其相变动力学分析等手段，澄清它们影响其晶化行为的机制，发展软磁纳米晶形成理论。研究热处理工艺参数对合金组织结构、磁性能和弯折韧性的影响规律，揭示合金性能与其成分、组织结构的相关性，阐明合金元素影响其软磁性能和弯折韧性的机理。为发展工业实用化的高性能纳米软磁合金提供理论依据和工艺技术支撑。

High Fe concentration Nanocrystalline alloys have been discovered as a promising soft magnetic material in our previous work. However, the extremely brittle nature for the nanocrystalline Fe-based soft magnetic alloys has generally been recognized to be the most serious disadvantage which limited their engineering application. The present proposal is devoted to a comprehensive study of the alloying effects of transition metals and metalloid element on the thermal stability, microstructural evolution, soft-magnetic properties and bending ductility of nanocrystalline FeSiBPCCu alloys were systematically investigated. First, the composition-amorphous structure formation-magnetic property correlation is to be clarified in the amorphous alloy system, from which the optimal alloy composition is proposed. The crystallization behaviors of these precursor amorphous alloys are then studied to reveal the underlying mechanism of minor alloying on nanodecomposition, and the corresponding nanocrystallization model will be put forth. Finally, the influence of the various control parameters of heat treatment on changing the crystallization counterparts, the microstructure length scale and hence the magnetic properties and bending ductility of the nanocrystalline alloys will be investigated, from which the correlation of composition-microstructure-soft magnetic property-bending ductility is to be established for the nanocrystalline soft magnetic alloys. The present study would provide theoretically useful guidelines and candidate materials for the development of industrially applicable nanocrystalline soft magnetic alloys with high saturation magnetization.