EVOLUTION OF NANOGRAINS AND SOFT MAGNETIC PROPERTIES OF Fe74Cu0.8Nb2.7Si15.5B7 BY ISOTHERMAL ANNEALING

2011 ◽  
Vol 25 (14) ◽  
pp. 1241-1251 ◽  
Author(s):  
SHEIKH MANJURA HOQUE ◽  
UMASREE DHAR ◽  
M. A. HAKIM ◽  
D. K. SAHA ◽  
HARI NARAYAN DAS
Keyword(s):  
Magnetic Properties ◽  
Melt Spinning ◽  
Isothermal Annealing ◽  
Amorphous State ◽  
Initial Permeability ◽  
Soft Magnetic Properties ◽  
Soft Magnetic ◽  
Type Composition ◽  
Long Time ◽  
Short Time

Fe -based alloy of the composition, Fe 74 Cu 0.8 Nb 2.7 Si 15.5 B 7 has been studied thoroughly in order to research the evolution of nanograins and soft magnetic properties. The composition has been significantly deviated from FINEMET type composition given by Fe 73.5 Cu 1 Nb 3 Si 13.5 B 9. It is hard to optimize composition to obtain equally good soft magnetic properties as FINEMET significantly deviating from conventional type alloy. Fe -based alloy of the composition, Fe 74 Cu 0.8 Nb 2.7 Si 15.5 B 7 has been prepared by single roller melt spinning machine. X-ray diffraction studies confirmed that the ribbon is in the amorphous state. Evolution of α- Fe ( Si ) nanograins from amorphous matrix were carried out by isothermal annealing in the temperature range from 550°C to 650°C for 1, 3, 5, 10, 20, 30, 40, 50 and 60 minutes. Frequency spectrum of real and imaginary part of complex initial permeability has been measured for the samples at different annealing conditions. Short time annealing has been proved to be more efficient than long time annealing for the samples of this composition for most of the annealing temperatures.

scholarly journals Optimization of Soft Magnetic Properties in Fe-B and Fe-B-Si Amorphous Alloys Obtained by Melt Spinning Method

2002 ◽  
Vol 102 (2) ◽  
pp. 309-316 ◽  
Author(s):  
P. Kwapuliński ◽  
Z. Stokłosa ◽  
A. Chrobak ◽  
J. Rasek ◽  
G. Haneczok
Keyword(s):  
Magnetic Properties ◽  
Amorphous Alloys ◽  
Melt Spinning ◽  
Soft Magnetic Properties ◽  
Soft Magnetic

Influences of the Adding Manners of b on the Stability and the Soft Magnetic Properties of Amorphous Fe52Co34Hf7B6Cu1 Alloys

2013 ◽  
Vol 320 ◽  
pp. 83-87 ◽  
Author(s):  
Yue Gu ◽  
Yue Sheng Chao
Keyword(s):  
Activation Energy ◽  
Magnetic Properties ◽  
Amorphous State ◽  
Soft Magnetic Property ◽  
Soft Magnetic Properties ◽  
Soft Magnetic ◽  
Transmission Electron ◽  
The Matrix ◽  
Quenching Method ◽  
The Stability

The stability and the soft magnetic properties of amorphous Fe52Co34Hf7B6Cu1 alloys have been investigated in this paper. Amorphous Fe52Co34Hf7B6Cu1 alloys ribbons are prepared by single-roller-quenching method. The differential thermal analysis (DTA), X-ray diffraction (XRD), Mössbauer Spectroscopy, transmission electron microscope (TEM) and vibrating sample magnetometer (VSM) were used for characterizing microstructures, soft magnetic properties, and evaluating the influence of adding manners of B on the stability of as-quenched specimens. The XRD curve shows a wide dispersion of peak, the TEM diffraction ring was dispersed cyclic, the pattern of the matrix was homogeneous, and the Mössbauer spectrum of as-quenched alloy presents a typical broadened and overlapped sextet, which confirms the as-quenched alloy in fully amorphous state. The DTA results showed the activation energy of Fe52Co34Hf7B6Cu1 alloy is 299.7KJ/mol. When pure B is replaced by FeB in preparing amorphous Fe52Co34Hf7B6Cu1 alloys, the activation energy reduced to 293.3 KJ/mol,and the soft magnetic property is decline according VSM results.

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

2003 ◽  
Vol 18 (12) ◽  
pp. 2799-2806 ◽  
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.

Structural Studies of the Relaxed Amorphous Phase in the Fe81B14Nb5 Alloy

2013 ◽  
Vol 203-204 ◽  
pp. 380-385 ◽  
Author(s):  
Małgorzata Karolus
Keyword(s):  
Magnetic Properties ◽  
Amorphous Phase ◽  
Magnetic Permeability ◽  
Amorphous Alloys ◽  
Melt Spinning ◽  
Soft Magnetic Materials ◽  
Soft Magnetic Properties ◽  
Structural Studies ◽  
Soft Magnetic ◽  
Melt Spinning Technique

Amorphous alloys based on iron, obtained by melt spinning technique, are modern and very promising soft magnetic materials. The thermal annealing at temperatures closed to the crystallization temperature can cause an increase of magnetic permeability more than 10 times i.e. the so called enhancement of soft magnetic properties effect (ESMP). It is usually explained by formation of iron nanocrystallites in amorphous surroundings or by formation of the relaxed amorphous phase. Such a microstructure leads to averaging out of magnetic anisotropy and cause the ESMP.

Influence of Melt-Spinning Parameters on the Structure and Soft Magnetic Properties of (Fe0.65Co0.35)88Zr7B4Cu1 Alloy

2010 ◽  
Vol 41 (5) ◽  
pp. 1313-1320 ◽  
Author(s):  
D. Arvindha Babu ◽  
A.P. Srivastava ◽  
B. Majumdar ◽  
D. Srivastava ◽  
D. Akhtar
Keyword(s):  
Magnetic Properties ◽  
Melt Spinning ◽  
Soft Magnetic Properties ◽  
Soft Magnetic

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

2015 ◽  
Vol 2015 ◽  
pp. 1-5 ◽  
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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