Magnetic properties of extruded nanocrystalline Fe-Nb-B alloys

Journal Article · Tue Nov 01 04:00:00 EST 1994 · IEEE Translation Journal on Magnetics in Japan

DOI:https://doi.org/10.1109/TJMJ.1994.4565956· OSTI ID:197665

Kojima, A; Horikiri, H; Kawamura, Y; Inoue, A; Masumoto, T ^[1]; Makino, A

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1. Tohoku Univ., Sendai (Japan)

A bulk Fe{sub 84}Nb{sub 7}B{sub 9} alloy was produced by extruding amorphous powder at temperatures (T{sub e}) between 653 and 723 K, at pressures (P{sub e}) between 824 and 1,208 MPa, and at a speed (V{sub e}) of 5 mm/s. The subsequent annealing of the extruded bulk alloy for 3.6 ks at temperatures between 873 and 973 K resulted in the formation of a (for the most part) single bcc phase, with grain sizes near 10 nm. The bulk alloy, extruded at a P{sub e} above 1,000 MPa, has a high relative density of 99%. The soft magnetic properties are better for bulk materials extruded at lower pressures, and the bulk alloy extruded at T{sub e} = 698 K and P{sub e} = 870 MPa exhibits a magnetization (B{sub 800}) of 1.40 T, a permeability of 1,123, and a coercive force (H{sub c}) of 47 A/m, values which are inferior to those of the bcc ribbon alloy (1.49 T, 22,000, 8 A/m). The difference between the soft magnetic properties of the bulk material and the ribbon forms is presumably due to the inhomogeneity of the microstructure, oxidation of the powder, and the remainder of a higher internal stress in the bulk alloy.

• Sponsoring Organization: USDOE
• OSTI ID: 197665
• Journal Information: IEEE Translation Journal on Magnetics in Japan, Journal Name: IEEE Translation Journal on Magnetics in Japan Journal Issue: 6 Vol. 9; ISSN ITJJER; ISSN 0882-4959
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
BORON ALLOYS
COERCIVE FORCE
EXPERIMENTAL DATA
IRON BASE ALLOYS
MAGNETIC PROPERTIES
NIOBIUM ALLOYS