Fe-based amorphous alloy ribbon and magnetic core formed thereby

Inactive Publication Date: 2006-01-05
HITACHI METALS LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Benefits of technology

[0008] Accordingly, an object of the present invention is to provide an Fe-based amorphous alloy ribbon having improved saturation magnetic flux density and soft magnetic characteristics, whose stress is sufficiently relaxed by a heat treatment for a relatively short period of time.
[0010] The first Fe-based amorphous alloy ribbon having excellent magnetic characteristics according to the present invention is represented by the general formula: FeaSibBcMx, wherein M is Cr and / or Ni, a is 78 to 86 atomic %, b is 0.001 to 5 atomic %, c is 7 to 20 atomic %, and x is 0.01 to 5 atomic %, (a+b+C+x) being 100. x is preferably 0.01 to 1 atomic % when M is Cr, and 0.1 to 5 atomic % when M is Ni. A heat treatment under predetermined conditions can provide this Fe-based amorphous alloy ribbon with an improved magnetic flux density and sufficiently relaxed stress. This Fe-based amorphous alloy ribbon preferably has a thickness of 25 to 40 μm, a saturation magnetic flux density of 1.6 T or more, and a magnetic flux density of 1.5 T or more in a magnetic field of 80 A / m.
[0012] The second Fe-based amorphous alloy ribbon having excellent magnetic characteristics according to the present invention is represented by the general formula: FeaSibBcCdMx, wherein M is Cr and / or Ni, a is 78 to 86 atomic %, b is 0.001 to 5 atomic %, c is 7 to 20 atomic %, d is 0.001 to 4 atomic %, and x is 0.01 to 5 atomic %, (a+b+c+d+x) being 100. x is preferably 0.01 to 1 atomic % when M is Cr, and 0.1 to 5 atomic % when M is Ni. A heat treatment under predetermined conditions can provide this Fe-based amorphous alloy ribbon with an improved magnetic flux density and sufficiently relaxed stress. This Fe-based amorphous alloy ribbon preferably has a thickness of 25 to 40 μm, a saturation magnetic flux density of 1.6 T or more, and a magnetic flux density of 1.5 T or more in a magnetic field of 80 A / m.

Problems solved by technology

Though silicon steel has a high magnetic flux density with low cost, it disadvantageously suffers from a core loss in high-frequency applications.
They also have large magnetostriction, vulnerable to the deterioration of characteristics due to stress.
However, the above conventional Fe-based amorphous alloy ribbons are not suitable as magnetic core materials for transformers because of low magnetic flux densities.
Because a low magnetic flux density necessitates a low maximum operation magnetic flux density, the magnetic core having a low magnetic flux density inevitably has large volume or weight.
Though core loss has been investigated on plates obtained from the above conventional Fe-based amorphous alloy ribbons, no investigation has been conducted with respect to stress generated when worked to magnetic cores.
Further, because a heat treatment needs a long period of time in the production method proposed by JP 10-324961, it is extremely poor in mass producibility.
In this case, because stress generated in the Fe-based amorphous alloys worked to magnetic cores for transformers is not sufficiently relaxed, the magnetic characteristics of the Fe-based amorphous alloys are extremely deteriorated.

Method used

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  • Fe-based amorphous alloy ribbon and magnetic core formed thereby
  • Fe-based amorphous alloy ribbon and magnetic core formed thereby
  • Fe-based amorphous alloy ribbon and magnetic core formed thereby

Examples

Experimental program
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Effect test

example 1

[0036] Alloy melts having compositions represented by FeaSibBcMx (a+b+c+x=100) as shown in Table 1 were rapidly quenched by a single roll method to produce amorphous alloy ribbons of 5 mm in width and 25 μm in thickness.

[0037] Each Fe-based amorphous alloy ribbon was wound to form a toroidal magnetic core of 19 mm in outer diameter and 15 mm in inner diameter, which was heat-treated in an Ar gas atmosphere. During the heat treatment, a magnetic field of 1 kA / m was applied in a direction aligned with the magnetic path of the core, and the temperature was elevated to an optimum heat-treating temperature between 320° C. and 370° C., at which the highest saturation magnetic flux density and other soft magnetic properties were obtained, over 2 hours, kept at each heat-treating temperature for 1 hour, and then cooled to 200° C. over 1 hour. The heat-treated ribbons were mostly amorphous. The resultant toroidal magnetic cores were measured with respect to a saturation magnetic flux densit...

example 2

[0043] 20 Samples 2-1 to 2-11 and 2-12 to 2-16 of various compositions were produced and heat-treated in the same manner as in Example 1. The core loss increase ratio Wr of each resultant Fe-based amorphous alloy ribbon is shown in Table 2 together with a composition, a heat treatment temperature, a saturation magnetic flux density Bs, a stress relaxation rate Rs, an average surface roughness Ra, and a space factor. The saturation magnetic flux density Bs and the stress relaxation rate Rs were measured in the same manner as in Example 1.

[0044] The core loss increase ratio Wr is a parameter expressing an increase ratio of the core loss when the operating magnetic flux density increases from 1.3 T to 1.4 T, which is represented by the following equation:

Wr=(W14 / 50−W13 / 50) / W13 / 50×100 [%]  (2),

wherein W13 / 50 represents a core loss at a magnetic flux density of 1.3 T and a frequency of 50 Hz, and W14 / 50 represents a core loss at a magnetic flux density of 1.4 T and a frequency of 50 ...

example 3

[0049] Alloy melts having compositions represented by FeaSibBcCdMx (a+b+c+d+x=100) as shown in Table 3 were rapidly quenched by a single roll method, to form Fe-based amorphous alloy ribbons of 5 mm in width and 25 μm in thickness. Each of the resultant Fe-based amorphous alloy ribbons was wound to form a toroidal magnetic core of 19 mm in outer diameter and 15 mm in inner diameter, and heat-treated in the same manner as in Example 1. The heat-treated alloys were mostly amorphous.

[0050] Each Sample was measured in the same manner as in Example 1 with respect to a saturation magnetic flux density Bs, a magnetic flux density B80 in a magnetic field of 80 A / m, a core loss W13 / 50 at a magnetic flux density of 1.3 T and a frequency of 50 Hz, a core loss W14 / 50 at a magnetic flux density of 1.4 T and a frequency of 50 Hz, and a stress relaxation rate Rs. The results are shown in Table 3.

TABLE 3Sam-pleBsB80W13 / 50W14 / 50RsNo.Composition[T][T][W / kg][W / kg][%]3-1Fe82Si2B13.95C2Cr0.051.641.61...

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Abstract

A magnetic core provided with a shape for a transformer by a cut-lap or step-lap method, which is constituted by an Fe-based amorphous alloy ribbon having excellent magnetic characteristics, which is represented by the general formula: FeaSibBcMx or FeaSibBcCdMx wherein M is Cr and / or Ni, a is 78 to 86 atomic %, b is 0.001 to 5 atomic %, c is 7 to 20 atomic %, x is 0.01 to 5 atomic %, and d is 0.001 to 4 atomic %, (a+b+c+x) or (a+b+c+d+x) being 100.

Description

FIELD OF TH INVENTION [0001] The present invention relates to an Fe-based amorphous alloy ribbon having excellent magnetic properties, and a magnetic core constituted by such an Fe-based amorphous alloy ribbon, and particularly to an Fe-based amorphous alloy ribbon and its magnetic core usable for various transformers, reactors, noise reduction parts such as choke coils for active filters, smoothing choke coils, common-mode choke coils, etc., laser power supplies, magnetic pulse power parts of accelerators, motors, generators, etc. BACKGROUND OF THE INVENTION [0002] Known as magnetic alloys having high saturation magnetic flux densities and low core losses used for various transformers and reactors, noise reduction parts such as choke coils for active filters, smoothing choke coils, common-mode choke coils and electromagnetic shields, laser power supplies, magnetic pulse power parts of accelerators, motors, generators, etc. are silicon steel and Fe-based amorphous alloys. Though sil...

Claims

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Application Information

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IPC IPC(8): C22C45/02
CPCH01F1/15308H01F3/14H01F3/04
Inventor NAOE, MASAMUOGAWA, YUICHIYOSHIZAWA, YOSHIHITO
Owner HITACHI METALS LTD
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