High-performance regulation over a wide temperature-range for multi-component FeCo-based amorphous alloys by non-isothermal heat treatment

The research of soft magnetic amorphous materials is confronted by a fundamental dilemma: although the addition of ferromagnetic elements can enhance saturation magnetic flux density ( B s ), it will diminish glass-forming ability (GFA). To address this trade-off, this study employs feature engineering to screen alloying elements that improve GFA while maintaining high magnetic performance. In this context, we systematically optimized a FeCo-based system, developing a nine-component alloy (Fe 4 Co 1 ) 85.5 Si 0.08 B 8.5 P 2.46 C 2.46 (ZrVCu) 1 by Inoue’s empirical criteria for amorphous formation. The alloy exhibits a high saturation magnetic induction of 1.74 T in the fully amorphous state, along with a wide thermal stability window ( ΔT x = 175 K) and a high crystallization activation energy ( E x2 = 980.63 kJ/mol), indicating excellent thermal stability and a broad processing window. After non-isothermal annealing, controlled nanocrystal precipitation further increases B s to 1.88 T. This dual optimization strategy—enhancing mixing entropy to improve GFA while regulating atomic size mismatch and chemical interactions to expand the crystallization window—provides a practical design paradigm for high- B s multicomponent FeCo-based amorphous nanocrystalline alloys.