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Indexed by:Journal Papers

Date of Publication:2020-03-01

Journal:JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS

Included Journals:EI、SCIE

Volume:497

ISSN No.:0304-8853

Key Words:Fe-based nanocrystalline alloys; Fe-B alloys; Alloying; Melt-spun; Soft magnetic properties

Abstract:The effects of Cu and Nb additions on the structure and magnetic properties of a Fe87B13 alloy in melt-spun and annealed states were investigated. Increase in Cu content from 1.0 to 1.7 at.% changes the melt-spun Fe87-xB13Cux alloy ribbons from a single amorphous phase to a composite of high-number-density nano-order alpha-Fe phase with an average grain size (D alpha-Fe) of 12.1 nm dispersing in the amorphous matrix. The crystallized structure after annealing gets refined with increasing the Cu content, and a small D alpha-Fe of 18.1 nm is obtained for the Fe85.3B13Cu1.7 alloy, which possesses a low coercivity (H-c) of 32.6 A/m and high saturation magnetic flux density (B-s) of 1.87 T. Minor addition of Nb reduces the D alpha-Fe in melt-spun Fe85.3-yB13Nby alloys but not obviously lowers the number density, while 3 at.% Nb makes the formation of fully amorphous phase. The D alpha-Fe in the crystallized alloys is decreased to 15.3 nm by alloying 2 at.% Nb, but increased to 31.4 nm with 3 at.% Nb. The Fe83.3B13Cu1.7Nb2 nanocrystalline alloy exhibits a lower H-c of 9.5 A/m combined with high B-s and effective permeability at 1 kHz of 1.75 T and 15000, respectively. The combined effects of competitive growth of the preexisting nano-order alpha-Fe particles and Nb-inhibited atoms diffusion contribute to the refinement of the nanocrystalline structure.