Soft Magnetic Properties of Co-Based Amorphous Alloys with Wide Supercooled Liquid Region

Glassy Fe65Co10Ga5P12C4B4 alloy powders with a large supercooled liquid region of 50 K before crystallization were synthesized in the particle size range below 125 μm by Ar gas atomization. With the aim of developing a large-size Fe-based glassy core with good soft magnetic properties, the consolidation method of spark plasma sintering was applied to the Fe65Co10Ga5P12C4B4 glassy powders. The existence of the supercooled liquid region enabled us to form a large-size glassy alloy disc 20 mm in diameter and 5 mm in thickness with a high relative density of 99.7% at the glass-transition temperature of 723 K and under the external applied pressure of 300 MPa. The resulting glassy core of 18 mm in outer diameter, 10 mm in inner diameter, and 4 mm in thickness exhibits good soft magnetic properties: 1.20 T for saturation magnetization, 6 A/m for coercive force, and 8900 for maximum permeability. The good soft magnetic properties of the Fe-based bulk glassy core are attributed to the combination of the high relative density and the maintenance of the single glassy structure.

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Soft Magnetic Properties of Nanocrystalline Fe–Co–B–Si–Nb–Cu Alloys in Ribbon and Bulk Forms

Journal of Materials Research ◽

10.1557/jmr.2003.0390 ◽

2003 ◽

Vol 18 (12) ◽

pp. 2799-2806 ◽

Cited By ~ 36

Author(s):

Akihisa Inoue ◽

Baolong Shen

Keyword(s):

Magnetic Properties ◽

Melt Spinning ◽

Glassy Alloy ◽

Nanocrystalline Alloy ◽

Supercooled Liquid ◽

Supercooled Liquid Region ◽

Exothermic Peak ◽

Liquid Region ◽

Soft Magnetic Properties ◽

Soft Magnetic

Ribbon and bulk nanocrystalline body-centered-cubic (bcc) (Fe,Co) alloys exhibiting good soft magnetic properties were synthesized in Fe71.5-xCoxB13.5Si10Nb4Cu1 system by the simple production processes of melt-spinning or casting and annealing. The glass-type alloys were formed in the Co content range below 30 at.%. These glassy alloys crystallized through two exothermic reactions. The first stage was due to the precipitation of nanoscale bcc-(Fe,Co) phase with a grain size of about 10 nm, and the second stage resulted from the decomposition of the remaining amorphous phase to α–(Fe,Co), (Fe,Co)2B, (Fe,Co)23B6, (Fe,Co)3Si, and (Fe,Co)2Nb phases. The glass transition temperature increased from 820 to 827 K with increasing Co content from 5 to 20 at.%, while the supercooled liquid region decreased slightly from 37 to 30 K because of the nearly constant crystallization temperature. By choosing the 10 at.% Co-containing alloy, we produced cylindrical glassy alloy rods 1.0 and 1.5 mm in diameter by copper mold casting. The subsequent annealing for 300 s at 883 K corresponding to the temperature just above the first exothermic peak caused the formation of nanoscale bcc-(Fe,Co) structure. The bcc-(Fe,Co) alloy rods exhibited good soft magnetic properties of 1.26 T for saturation magnetization and 5.0 A/m for coercive force, which were comparable to those for the corresponding bcc-(Fe,Co) alloy ribbon. The nanocrystalline alloy in a bulk form is encouraging for future use as a new type of soft magnetic material that requires three-dimensional shapes.

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Improvement of the soft magnetic properties of Fe-based glassy alloys with a large supercooled-liquid region

IEEE International Digest of Technical Papers on Magnetics Conference ◽

10.1109/intmag.2002.1001062 ◽

2003 ◽

Author(s):

N. Mitrovic ◽

S. Roth ◽

J. Eckert

Keyword(s):

Magnetic Properties ◽

Supercooled Liquid ◽

Supercooled Liquid Region ◽

Liquid Region ◽

Soft Magnetic Properties ◽

Soft Magnetic ◽

Glassy Alloys

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Glass formation, nanocrystallisation and magnetic properties of the (Fe1–xCox)79Nb3B18 (x = 0, 0.15, 0.3, 0.45, 0.6, 0.75) metallic glasses

International Journal of Materials Research (formerly Zeitschrift fuer Metallkunde) ◽

10.1515/ijmr-2020-1110710 ◽

2020 ◽

Vol 111 (7) ◽

pp. 600-606

Author(s):

Lijuan Yao ◽

Man Zhu ◽

Kun Li ◽

Zengyun Jian ◽

Fang’e Chang

Keyword(s):

Magnetic Properties ◽

Electrical Resistivity ◽

Supercooled Liquid ◽

Supercooled Liquid Region ◽

Industrial Applications ◽

Liquid Region ◽

Soft Magnetic Properties ◽

Soft Magnetic ◽

Glassy Alloys ◽

Saturation Magnetisation

Abstract The glass-forming ability (GFA), nanocrystallisation, electrical resistivity and soft magnetic properties of (Fe1-xCox)79Nb3B18 (x = 0, 0.15, 0.3, 0.45, 0.6, 0.75) glassy alloys were investigated. We found that the substitution of Fe by Co is beneficial for improving the GFA. As-spun (Fe0.55Co0.45)79Nb3B18 glassy alloys show the best GFA, along with excellent soft magnetic properties in the supercooled liquid region, with a saturation magnetisation and coercivity of 140 A · m2 · kg-1 and 19.9 A · m-1, respectively, at 60 K. With increasing Co content, the electrical resistivity initially decreases rapidly, and then fluctuates around approximately 70 ± 4 μΩ cm. With increasing the annealing temperature, the saturation magnetisation improves initially, but then decreases for the (Fe0.4Co0.6)79Nb3B18 alloy, and the coercivity does not significantly improve. These newly developed FeCoNbB multicomponent alloys exhibit appreciable GFA, good magnetic properties and low material cost, and they can serve as a promising soft magnetic material for use in industrial applications.

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Fabrication of Fe-6.5wt%Si Ribbons by Melt Spinning Method on Large Scale

Advances in Materials Science and Engineering ◽

10.1155/2015/296197 ◽

2015 ◽

Vol 2015 ◽

pp. 1-5 ◽

Cited By ~ 10

Author(s):

Y. F. Liang ◽

S. Wang ◽

H. Li ◽

Y. M. Jiang ◽

F. Ye ◽

...

Keyword(s):

Magnetic Properties ◽

Melt Spinning ◽

Large Scale ◽

Low Cost ◽

Solidification Rate ◽

Supercooled Liquid ◽

Supercooled Liquid Region ◽

Liquid Region ◽

Soft Magnetic Properties ◽

Soft Magnetic

Melt spinning method has been widely applied for fabrication of Fe-based amorphous/nanocrystalline ribbons in industry. Compared with Fe-based amorphous/nanocrystalline alloys, Fe-6.5wt%Si high silicon steel is of low cost and has comparable excellent soft magnetic properties. Due to higher melting point and absence of supercooled liquid region, fabrication of Fe-6.5wt%Si ribbons is very hard and is only on lab scale. In this paper, we report that large scale fabrication of Fe-6.5wt%Si ribbons was successful and microstructures, ordered structures, and mechanical and soft magnetic properties of the ribbons were investigated. Due to rapid solidification rate, the ribbons were of ultrafine grains, and low degree of order and exhibited some extent of bending and tensile ductility. After heat treatment, excellent soft magnetic properties were obtained. Due to near-zero magnetostriction, the ribbons are promising to be used in electric devices with high frequencies where low noises are required.

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Structure and Soft Magnetic Properties of Bulk Fe-Al-Ga-P-C-B-Si Glassy Alloys Prepared by Consolidating Glassy Powders

MRS Proceedings ◽

10.1557/proc-644-l12.13 ◽

2000 ◽

Vol 644 ◽

Author(s):

Akihisa Inoue ◽

Shoji Yoshida ◽

Takao Mizushima ◽

Akihiro Makino

Keyword(s):

Magnetic Properties ◽

Glassy Alloy ◽

Supercooled Liquid ◽

Supercooled Liquid Region ◽

Liquid Region ◽

Soft Magnetic Properties ◽

Powder Metallurgy Technique ◽

Soft Magnetic ◽

High Relative Density ◽

Bulk Glassy Alloy

AbstractWith the aim of developing a bulk glassy Fe-based alloy with good soft magnetic properties by the powder metallurgy technique, we have applied the pulse current sintering technique to a Fe70Al5Ga2P9.65C5.75B4.6Si3 glassy alloy powder with a large supercooled liquid region of 60K before crystallization. The existence of the supercooled liquid region was found to enable us to form a bulk glassy alloy with a very high relative density of 99%. The resulting bulk glassy alloy exhibits good soft magnetic properties, i.e., 1.17T for flux density at a field of 800A/m, 12.0A/m for coercive force and 8000 for maximum permeability which are much superior to those for the bulk amorphous Fe-Si-B alloy prepared by the same sintering method. The much better soft magnetic properties for the multicomponent Fe-based bulk alloy are attributed to the combination of the high relative density and the unique amorphous structure with the features of high packing density and long-range homogeneous atomic configurations. The first success of forming the bulk amorphous alloy with good soft magnetic properties by the powder metallurgy technique is expected to enable us to use as practical soft magnetic materials.

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