| This work proposes a new concept for nanocrystalline alloy design and structure regulation, namely the design of a new type of alloy that does not contain elements that promote nucleation and inhibit diffusion. By quenching pre-made high-density nucleation points at a critical cooling rate and refining grains through a metallic transient enriched interface, a uniform and fine nanocrystalline structure is obtained. Through ingenious design, with only 4.6wt.% of common metalloid elements (B, Si, P, and C) combined, it achieves the effect of stabilizing the quenched amorphous phase and the nanocrystalline inter-matrix phase. It reconciles the contradiction between the saturation magnetic induction strength and the forming ability, significantly enhancing the feasibility of industrialization of high magnetic sensitivity nanocrystalline alloys and reducing the cost of the alloy. This unique design is equivalent to nanocrystallizing silicon steel with the same iron content, removing the adverse effects of grain boundaries on soft magnetic properties, and retaining the ultra-high saturation magnetic induction strength of the α-Fe phase. The Fe85.5B10Si2P2C0.5 alloy designed by the new concept has a Bs of 1.87T, close to that of silicon steel, and its uniform, fine amorphous-nanocrystalline dual-phase structure gives it excellent soft magnetic properties. This heterogeneous structure and lightweight alloy strategy provide ideas and references for the development of next-generation magnetic materials. |
