Owing to excellent soft magnetic properties, Fe based nanocrystalline amorphous materials with high Fe content exhibit significant potential for applications in next-generation power electronic devices. However, large-scale industrialization has been limited by low amorphous forming ability and insufficient bending ductility after annealing. In this work, the amorphous forming ability, the crystallization behavior, thermal stability, microstructure, bending ductility and magnetic properties of high-Fe-content Fe 85- x Si 2 B 9 C 2 P 2 Cu x ( x = 0.2, 0.4, 0.6, 0.8, 1.0) alloys are systematically investigated. The results show that Cu addition reduces the primary crystallization temperature from 694 K to 669 K and increases the crystallization activation energy for α-Fe nucleation from 154.55 to 191.34 kJ/mol, which promotes nucleation while suppressing excessive grain growth, thereby improving thermal stability. The Fe 84.8 Si 2 B 9 C 2 P 2 Cu 0.2 alloy annealed at 698 K possesses the maximum B s of 1.82 T and bending ductility of 2.61%, exhibiting an excellent soft magnetic property. This study demonstrates a viable strategy to overcome the trade-off between magnetic performance and bending ductility, offering new insights into the design of advanced soft magnetic materials for high-performance electromagnetic applications.
Ding et al. (2026) studied this question.