Identifying the optimal amorphous precursor alloy system for dual-phase nanostructure formation according to the impurity tolerance and crystallization mechanism

Abstract

The amorphous precursor alloys for nanostructure with high Bs always exhibit a low impurity tolerance, inhibiting mass production. Here, we comparatively studied the FeBSiCu, FeBPSiCu and FePSiCu alloy systems in Fe83B12-xPxSi4Cu1 (x = 0–12) alloys made with industrial raw materials. Fully amorphous ribbons were readily prepared in the Fe83B12Si4Cu1 and Fe83P12Si4Cu1 alloys. It is difficult to avoid the surface crystallization induced by the impurities in Fe83B12-xPxSi4Cu1 (x = 2–8) amorphous alloys with a relatively high amorphous formability. The Fe83B12Si4Cu1 alloy exhibits a large crystallization temperature interval (ΔT) which can be further widened by P micro-alloying. The macro-substitution of B by P will lead to a significant decrease of ΔT. The ΔT of the novel Fe83P12Si4Cu1 alloy can be effectively widened by increasing the Fe content and microalloying of B, exhibiting a good potential for the combination of superior ΔT, AFA and impurity tolerance. The low impurity tolerance in the Fe83B12-xPxSi4Cu1 alloys is ascribed to the significant difference in the metallurgical properties of the Fe–B and Fe–P alloys, needing new impurity purification processes. These results will bring a new perspective to develop high Bs precursor alloys and experimental references for critical industrialization.