Tailoring the structure and properties of Fe-based amorphous ribbons via melt temperature

Abstract

In the present study, the structure and properties of Fe₇₈Si₉B₁₃ amorphous ribbons produced in an industrial production process at casting temperatures of 1500, 1450, and 1350 ℃ were investigated. The analysis focused on surface morphology, microstructure, thermal stability, and magnetic anisotropy. The results showed that, compared to the amorphous ribbon produced at 1350 ℃, the ribbon fabricated at 1500 ℃ exhibited smoother edges, smaller thickness variation, higher thermal stability, a more uniform microstructure, and superior magnetic properties. This phenomenon could be attributed to the more uniform melt structure at higher temperatures, leading to a more homogeneous amorphous ribbon during the cooling process. A higher melt temperature enhanced the fluidity of the melt, promoting the formation of a sufficient molten pool and reducing fluctuations within the pool. A high melt temperature inhibited the precipitation of nanoclusters in the amorphous ribbons, improved atomic spacing, and enhanced atomic motion. The reduced coercivity and core loss were due to the significant decrease in interlayer eddy current losses, which resulted in excellent surface morphology. The enhanced melt fluidity at higher melt temperatures facilitated the thickness distribution of the amorphous ribbon, leading to a smoother surface morphology, consequently, superior soft magnetic properties.