Design of FeSiBPCu soft magnetic alloys with good amorphous forming ability and ultra-wide crystallization window

The Fe81.3Si4B13-xPxCu1.7 soft magnetic alloys with high Cu and proper P elements addition were syn-thesized with the aim of ensuring the amorphous forming ability (AFA) while expanding the crystalliza-tion window (CW). It is found that the atomic ratio of P/Cu of similar to 3 is advantageous for AFA whereas a small amount of P addition promotes the precipitation of alpha-Fe grains and excessive P addition induces surface crystallization behavior of the present alloys. High Cu concentration can expand the annealing temperature (Ta) window whereas proper P addition effectively expands the annealing time (ta) window. The Fe81.3Si4B8P5Cu1.7 soft magnetic alloy was successfully synthesized with a large Ta window of up to 130 degrees C and ta window of 90 min, which is a breakthrough for nanocrystalline alloys with high saturation magnetization. Microstructure analysis reveals that the ultra-wide CW is related to the unique nucleation mechanism, that is, the alpha-Fe grains are precipitated attaching to the Cu or CuP clusters and enveloping the Cu clusters, resulting in the high number density of alpha-Fe nanocrystals. The ultra-wide CW promises the potential material in flexibly choosing the annealing process according to the performance.(c) 2023 Published by Elsevier Ltd on behalf of The editorial office of Journal of Materials Science & Technology.

Automated summary

The Fe81.3Si4B13-xPxCu1.7 soft magnetic alloys with high Cu and proper P elements addition were synthesized to ensure the amorphous forming ability (AFA) and expand the crystallization window (CW). It was found that an atomic ratio of P/Cu around 3 is advantageous for AFA, and a small amount of P addition promotes the precipitation of alpha-Fe grains. High Cu concentration expands the annealing temperature (Ta) window, while proper P addition enlarges the annealing time (ta) window. The successful synthesis of the Fe81.3Si4B8P5Cu1.7 soft magnetic alloy with a large Ta window of up to 130 degrees C and ta window of 90 min is a breakthrough for nanocrystalline alloys with high saturation magnetization.