JPS6267149A - Ultraquickly cooled composite magnetic alloy - Google Patents

Abstract

PURPOSE:To obtain an ultraguickly cooled thin alloy strip of a low eddy current loss by forming a non-magnetic compd. on the surface of the ultraquickly cooled thin alloy strip to finely segment the magnetic domains of the thin strip. CONSTITUTION:The ultraquickly cooled thin magnetic alloy strip is heat-treated in air or gaseous N2 to form the compd. of oxide or nitride, etc. on the surface of the thin magnetic alloy strip. The above-mentioned compd. is extremely effectively formed on the surface of the ultraquickly cooled magnetic alloy strip at the low temp. (200-300 deg.C) heat treatment for a short period if an alloy having the compd. forming free energy lower than the compd. forming free energy of the main component for the base metal is added thereto at <=5%. As an example, the formation of the oxide on the surface of the ultraquickly cooled thin Fe and Co magnetic alloy strip is executed in the following manner: A metal having the oxide forming free energy of the value further smaller than the value of Si having the smallest oxide forming free energy among the main components Fe, Co, etc. is selected as the additive for accelerating the formation of the oxide. Said metal is exemplified by Ti, Ba, Zr, Ce, Al, Mg, Ca, B, etc.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a magnetic alloy produced by an ultra-quenching method,
In particular, it relates to an ultra-quenched composite magnetic alloy in which a compound such as an oxide or nitride is formed on the surface of a magnetic alloy ribbon.

[Conventional technology]

Recently, in the field of electronic equipment, transformers, choke coils, saturable reactors, and
Products such as noise filters and magnetic heads are being commercialized. by the way.

One of the important properties of these products is good eddy current loss characteristics (lower eddy current loss). One method for improving the eddy current loss characteristics is to make the ultra-quenched magnetic alloy ribbon thinner to increase its electrical resistance. However, there are technical limits to reducing the thickness of ultra-quenched magnetic alloy ribbons, and therefore, as another method to reduce eddy current loss in the high frequency range, we have developed After adding a solid solution powder, the molten metal is ejected from a nozzle/slit onto the surface of a rotating cooling roll to disperse the non-solid solution powder in the magnetic alloy matrix, thereby making use of a so-called second phase particle-dispersed ultra-quenched alloy. has been proposed (Japanese Unexamined Patent Publication No. 59-47352).

[Problem that the invention seeks to solve]

However, when mechanically mixing non-solid solution powders as described above, generally. against the molten base metal.

There is a problem in that it is difficult to uniformly disperse a non-solid solution with a low density, and an ultra-quenched magnetic alloy with good eddy current loss characteristics cannot be obtained.

It is an object of the present invention to provide a magnetic alloy with low eddy current loss.

[Means for solving problems]

The present invention is an ultra-quenched composite magnetic alloy in which a non-magnetic compound is formed on the surface of an ultra-quenched magnetic alloy as a base material, and the magnetic domains are subdivided with impurities caused by the non-magnetic compound to achieve low eddy current loss. A magnetic alloy is obtained.

Remaining days below 〔Example〕 The present invention will be explained below with reference to Examples.

First, an overview of the present invention will be explained.

The core loss P and L of the ultra-quenched magnetic alloy ribbon are the magnetic hysteresis loss p
The sum of h and eddy current loss PE is given by the following equation (1).

PL = Ph-f + PE (1) (where f is the frequency) By the way, when considering the structure factor due to ultra-rapid solidification, the eddy current loss PK is equal to Pry & Beam.
is given by equation (2).

However, d is the thickness of the ultra-quenched magnetic alloy, Bm is the maximum amplitude of magnetization, f is the frequency, R is the electrical resistance, 2L is the magnetic domain width, and B
s is the saturation magnetization and K is 2 Vd and Brr1/B
This is a boosting function with 8 as a variable.

By the way, the eddy current loss PE of the Fe-based ultra-quenched magnetic alloy in the high frequency region is estimated to be 90 inches or more of the total loss. In order to lower this PK, 2L in equation (2) should be made smaller. Reducing 2L means subdividing the magnetic domain of the magnetic alloy and increasing the number of domain walls. In the present invention, compounds such as oxides or nitrides are generated on the surface of the ultra-quenched magnetic alloy ribbon by heat-treating the ultra-quenched magnetic alloy ribbon in a predetermined atmosphere (air or nitrogen gas). An ultra-quenched composite magnetic alloy with low eddy current loss can be obtained. The above-mentioned compounds were heated for a short period of time at low temperatures (200
~300°C) In order to easily generate on the surface of ultra-quenched magnetic alloy ribbon through heat treatment, it is extremely effective to add 5% or less of a metal whose compound formation free energy is lower than that of the main component of the base material. .

- For example, in order to generate Fe-based and Co-based super-ultra-quenched alloy ribbon surface oxides, its main components Fe+Co,
Among B, St, etc., a metal having an even smaller value than Si, which has the smallest oxide formation free energy, may be selected as the oxide formation promoting additive. That is #2
At 50°C, the free energy of St oxide formation ΔG
= -186000 (m/, !i'+1 molo2)
A metal 1 with a value smaller than, for example, g Ti e Ba
eZr r Ce, kl, Mge Ca
# You can choose Be etc. On the other hand, in the case of nitride formation, as in the case of oxide formation, a metal with a value smaller than B, which has the smallest nitride formation free energy ΔG among the main components, should be selected as the nitride formation promoting additive. Bye.

That is, at 250°C, the free energy of nitride formation of B ΔG = -100000 (cal/17 molN2)
Metal 1 with a value smaller than, for example, Zr + 'N
You can choose e Ce t At etc.

By adding the above-mentioned oxide or nitride generation promoter to the base material and performing heat treatment in an appropriate atmosphere, oxides or nitrides can be easily generated on the surface of the above-mentioned magnetic alloy. These compounds such as oxides and nitrides become contaminants (impurities), and the magnetic domains on one surface are deformed and fragmented. As a result, the eddy current loss PL according to equation (2) decreases.

An embodiment of the present invention will now be described.

As a sample, an inner diameter of 20. Five wound cores with an outer diameter of 25 degrees and a height of 5 (fins) are each vacuum-treated.
The sample was heat-treated in nitrogen and air at a temperature of 250° C. for 1 hour.

FIG. 1 shows an enlarged view of the surface of a sample heat-treated in nitrogen gas using an electron microscope. In Figure 1, it is Zr nitride that can be seen scattered in the form of particles. On the other hand, in the case of a sample heat-treated in vacuum, no particulate compounds (nitrides) as seen in FIG. 1 are observed. Furthermore, in the case of samples heat-treated in air, many particulate compounds (oxides) are observed, as seen in samples heat-treated in nitrogen.

Figure 2 shows the above-mentioned (300°C for 1 hour) heat treated in vacuum, nitrogen atmosphere, and air.
F79”4B17) 99zrI wound core loss PL (w
att/9) and Zr-free Fe 79Sl 4B
Vacuum heat treatment of a wound core made of 14 (temperature 300℃ for 1 hour)
A comparison with the later PL is shown. In addition, in FIG.

(F79””4B17) Each rolled core made of 99zrI was placed in a vacuum.

All those heat-treated in nitrogen atmosphere and air are indicated by numbers 1 and 2.3, respectively r Fe 79 S j 4B 1
The measurement conditions were as follows: the maximum amplitude of magnetization (Bm) was 1 kG.
(kilogauss). As is clear from the drawings.

The PL of the Zr-free material has a larger value than any of the heat-treated materials with Zr=1% additive. Further, in the case of Zr=1% additive material, the case of heat treatment in vacuum has the largest PLO value. When the heat treatment is performed in an atmosphere (nitrogen gas/air), the PL is significantly reduced compared to that in a vacuum.

〔Effect of the invention〕

As explained above, according to the present invention, compounds such as oxides or nitrides are generated on the surface of the ultra-quenched alloy ribbon to subdivide the magnetic domains of the ribbon, thereby achieving ultra-low eddy current loss. It is possible to obtain a rapidly solidified alloy ribbon, and therefore it is possible to commercialize an inductor with low eddy current loss.

[Brief explanation of drawings]

FIG. 1 is an enlarged view of the surface of a sample of (Fe79Si4B+ 7)99Zr1 amorphous alloy heat-treated at 600° C. for 1 hour in a nitrogen gas atmosphere using an electron microscope. FIG. 2 is a diagram showing the frequency dependence of eddy current loss (Pt). Figure 1: 10,000■

Claims (1)

[Claims] 1. An ultra-quenched composite magnetic alloy characterized in that a non-magnetic compound is produced on the surface of an ultra-quenched magnetic alloy thin body produced using an ultra-queue cooling method. 2. The ultra-quenched composite magnetic alloy according to claim 1, wherein the non-magnetic compound is an oxide. 3. The super-quenched composite magnetic alloy according to claim 1, wherein the non-magnetic compound is a nitride. 4. Claim 1, characterized in that a metal having a lower free energy of compound formation than the main component of the mother alloy is added to the mother alloy of the ultra-quenched magnetic alloy thin body. Ultra-quenched composite magnetic alloy.