KR930010639B1 - Fe-soft magnet materials - Google Patents

Abstract

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Description

Fe base soft magnetic alloy

1 is a graph showing a change in core loss with a change in the alloy heat treatment temperature of the alloy of the present invention and the comparative example.

2 is a graph showing the magnetic properties of a quenched alloy according to the change in the amount of Y in the alloy.

3 is a graph showing the change of permeability and iron loss according to the change of the particle diameter in the alloy.

The present invention relates to Fe soft alloys.

Conventionally, iron cores made of crystalline materials such as permalloy or ferrite have been used in high frequency devices such as switching regulators. However, the resistance ratio of the Fermaloy is low, resulting in large core loss at high frequencies. In addition, although the iron loss of ferrite at high frequency is small, the magnetic flux density is as small as 5000 G at most. Therefore, when used at a high operating magnetic flux density, the ferrite is close to saturation, and iron loss is increased.

Recently, it has become desirable to reduce the size of transformers used at high frequencies, such as power transformers, smooth choke coils and common mode choke coils used in switching regulators.

However, if the size is reduced, the operating magnetic flux density is increased, and increasing the ferrite iron loss is a serious problem.

For this reason, amorphous magnetic alloys, i.e. alloys without crystal structures, have recently been attracting attention and are being used in part because of their good soft magnetic properties such as high permeability and low coercive force. However, the amorphous magnetic alloy contains metalloid (P, C, B, Si, Al, Ge, etc.) as an amorphous element based on Fe, Co, Ni, and the like. However, not all of these amorphous magnetic alloys have low iron loss in the high frequency region.

An iron-based amorphous alloy is wrapped and has an extremely small iron loss of about one quarter of the silicon field in the frequency range of 50-60 Hz. However, these have extremely large iron losses in the high frequency range of 10-50 Hz and are therefore not very suitable for use in the high frequency region of the field such as in switching regulators.

In order to overcome these disadvantages, an attempt has been made to replace a portion of Fe with a nonmagnetic metal such as Nb, Mo, or Cr to lower magnetostriction, lower scratches, and increase permeability. However, deterioration of the magnetic properties due to curing, shrinkage, etc. of the resin at the time of resin molding, for example, is greater than that of Co-based alloys, thereby failing to obtain the above-described characteristics satisfactory with such materials when used in the high frequency region.

In addition, Co-based amorphous alloys have been used in magnetic parts for electronic devices such as saturable reactors because of low iron loss and high angular ratios in the high frequency region. However, the cost of Co-based alloys is relatively high, making it uneconomical to make such materials.

As described above, although the Fe-based amorphous alloy is composed of inexpensive soft magnetic material, relatively various problems occur and are worse than the Co-based amorphous alloy in terms of iron loss and permeability. On the other hand, Co-based amorphous alloys, although having good magnetic properties, are not practical in industry due to the high cost of such materials.

Accordingly, it is an object of the present invention to provide a Fe-based soft magnetic alloy having a high saturation magnetic flux density and good soft magnetic properties in the high frequency region.

According to the present invention, there is provided a Fe-based soft magnetic alloy having microcrystalline particles, such as the following general formula:

Fe _100-abcd M _a M ' _b Y _c N _d

M: at least one element selected from the group consisting of Cu, Ag, Au, Zn, Sn, Pb, Sb and Bi.

M ': at least one element selected from the group consisting of periodic elements IVa, Va, VIa elements, Mn, Co, Ni and Al

Y: at least one element selected from the group consisting of Si, P and B

0.01≤a≤5 (at.%)

0.1≤b≤10

15≤c≤28

0∠d≤8

In a preferred specific embodiment, the microcrystalline particles in the alloy is preferably present in more than 30% by area ratio.

In addition, it is preferable that at least 80% of the microcrystalline particles have a grain size of 50 GPa-300 GPa.

The reason for limiting 80% or more in the microcrystal present in 30% by area ratio to 50Å-300Å is that 80% or more in the microcrystal present in 30% by area ratio means that the particle diameter is in the range of 50Å-300Å. This is because, when used, an excellent magnetic alloy can be obtained, and when the crystal grains are less than 30%, the amorphous phase becomes 70% or more, and when the amorphous phase increases, iron loss and magnetostriction become large, and a desirable magnetic alloy is obtained. As for the reason for the limitation of the particle diameter, the smaller the particle diameter is, the better the magnetic properties are, but it is difficult to produce less than 50 μs, and as compared with the magnetic effect obtained by less than 50 μs, Since the magnetic properties of the film cannot be improved, the range is set in this range. In addition, when microcrystals having a particle diameter of more than 300 GPa are included, various magnetic properties are degraded as described above.

The “area area ratio” of the microcrystalline particles means, for example, the surface ratio occupied by the microparticles relative to the entire surface of the alloy surface measured by light microscopy or microscopic experiment.

In order to obtain the desired composition of the alloy of the present invention, it is necessary to maintain the balance of the composition within the limits as described later.

The alloy according to the present invention is at least one of Fe: N: Cu, Ag, Au, Zn, Pb, Sb and Bi: Group IVa, Va and VIa, Mn, Co, Ni and Al according to the following formula: At least one element: and at least one of Si, P, and B.

Fe _100-abcd M _a M ' _b Y _c N _d

M: at least one element selected from the group consisting of Cu, Ag, Au, Zn, Sn, Pb, Sb and Bi.

M ': at least one element selected from the group consisting of Groups IVa, Va, VIa, Mn, Co, Ni and Al on the periodic table

Y: at least one element selected from the group consisting of Si, P and B

0.01≤a≤5 (at.%)

0.1≤b≤10

15≤c≤28

0 <d≤8

In order to obtain the desirable properties of the novel alloy, it is important that the alloy of the present invention comprises the constituents in the amounts described above.

M is at least one element selected from the group consisting of Cu, Ag, Au, Zn, Sn, Pb, Sb and Bi.

These elements are effective in improving corrosion resistance, preventing grains from coarsening, and improving soft magnetic properties such as iron loss and permeability. However, if it is too small, the effect of the addition is not obtained.

On the other hand, the presence of a large tree ＂M＂ causes a decrease in magnetic properties. Therefore, 0.01 to 5 at. The range of% is appropriate, preferably the amount is 0.5 to 3 at.%.

The reason for limiting the range of M as mentioned above is compared with respect to the alloy to which Cu is added and the alloy to which Cu is not added concretely, for example.

In this case, Fe ₇₂ Cu ₂ Nb ₃ Si ₃ B ₈ N ₂ is selected as the alloy (alloy 1) to which Cu is added, and Fe ₇₅ Nb ₃ Si ₁₃ is selected as the alloy (alloy 2) to which Cu is not added. Select B ₉ . These alloys were each obtained by performing annealing under an optimum heat treatment condition in which amorphous by the single roll method and the highest permeability is obtained. The obtained alloy is heat-treated at a crystallization temperature or higher in alloy 1, and mainly consists of microcrystals of about 100 kPa, while alloy 2 is mainly composed of an amorphous phase with an optimum heat treatment condition below the crystallization temperature. All magnetic properties of these alloys are as described in Table 1 below.

TABLE 1

* One… Reduction after 24 hours of initial value due to corrosion in 1N HCl aqueous solution.

* 2… 10 kHz, 0.2 T

* 3... 1 kHz, 2 mOe

As is also apparent from this table, the effect of containing M is small in corrosion resistance and low in iron loss, and the permeability can be obtained by one or more orders of magnitude.

＂M＂ is an effective element to improve soft magnetic properties by uniformizing grain size and reducing magnetostriction and magnetic anisotropy.

It is also an effective element for improving magnetic properties against temperature changes. However, if the amount of ＂M＂ is too small, the effect of addition cannot be obtained. On the other hand, if too large, the saturation magnetic flux density decreases.

Therefore, the amount of [M] is 0.1 to 10at. % Range, preferably the amount is 1-7at. %, More preferably 1.5-5 at. %to be. As a specific reason for limiting the amount of ＂M 첨가 added, Al is added as an alloy to which Al is added (alloy 3), and Fe ₇₁ Cu ₂ Nb ₃ Si ₁₁ Al ₂ B ₆ N ₂ is selected, and Al is added. As the alloy that does not have, the permeability, iron loss, magnetostriction, and magnetic anisotropy energy will be described using the alloy 2 (Fe ₇₅ Nb ₃ Si ₁₃ B ₉ ) described above.

This alloy 3 is obtained by performing annealing under optimum heat treatment conditions that can be amorphous by the single roll method and obtain the highest permeability. Alloy 3 thus obtained is heat-treated above the crystallization temperature, and mainly consists of microcrystals of about 100 GPa.

All magnetic properties of these alloys are as shown in Table 2 below.

TABLE 2

As apparent from the above table, the effect of containing [M] is small in corrosion resistance, low in iron loss, small in magnetostriction, and very high in permeability.

In addition to the effects described above, the various additive elements in M 'exhibit respective effects as follows:

In the case of group IVa elements, the range of heat treatment conditions to obtain optimum magnetic properties is expanded:

In the case of group Va element and Mn, improvement of workability such as improvement of embrittlement and cutting:

For group VIa elements, improved corrosion resistance and surface shape:

In the case of Al, it is effective for miniaturization of crystal grains and reduction of magnetic anisotropy, which is effective in improving magnetostriction and soft magnetic properties.

＂Y＂ is an element effective in amorphizing the alloy during production and directly depositing microcrystals. If the amount is too small, the effect of supercooling at the time of manufacture is hard to be obtained, and the above-described state is not obtained. On the contrary, if the amount of YY is too large, the saturation magnetic flux density is lowered and the above state is difficult to be obtained. Excellent magnetic properties are not obtained.

Thus, 15-28at. Select the amount in the range of 18-26at. The range of% is preferable.

The change in magnetic properties of the quenched alloy depending on the amount of Y contained in the alloy depends on the diffraction energy intensity of the strongest peak 110 of bccFe as a result of X-ray diffraction (CuKa). It becomes clear by comparison.

For example, an alloy of Fe _91.5-c Cu _3.5 Nb ₃ (Si _0.55 B _0.45 ) cN ₂ , for example, may be measured by varying the amounts of Y (Si, B), as shown in FIG. You get

In FIG. 2, the measured intensity of C = 10 is denoted by Io, and is expressed as I / Io compared with the measured intensity I at the value of Y amount, respectively. As can be clearly seen from FIG. 2, if the C value of the Y amount is in the range of 15 to 28, it can be confirmed that amorphousness is possible in the alloy composition. In addition, in FIG. 2, the permeability (1 kHz) when the heat treatment is performed under the optimum processing conditions for obtaining the highest permeability with respect to the change amount of the C value of the Y amount, and the C value of the amount of Y being quantified is It can be seen that a high permeability can be obtained in the range of 15 to 28.

In particular, it is preferable that the ratio of Si / B or Si / P is one or more.

As mentioned above, the specific reason for limiting the ratio of Si / B or Si / P to one or more is compared with four types of alloys (alloys 4-7) shown next. The four kinds of alloys were amorphous by the single roll method, and then heat treated under optimum heat treatment conditions to obtain the highest permeability. In these four kinds of examples, all of them are heat treatment at or above the crystallization temperature, and are composed of about 100 GPa of microcrystals. For these four kinds of alloys, their magnetic properties are shown in Table 3 below.

TABLE 3

From Table 3, the alloy 4 and the alloy 6 having a Si / B or Si / P ratio of 1 or more have less iron loss than the alloys 5 and 7 having a Si / B or Si / P ratio of 1 or less, and the magnetic permeability is very large. Able to know.

N is included because it is effective for obtaining the optimum magnetic properties by widening the range of heat treatment conditions.

However, if the amount of N is too large, it is difficult to obtain microcrystals, so the amount is made 8 at% or less.

It is preferable that the quantity is 6 at% or less, and it is more preferable that it is 4 at% or less.

The reason for adding nitrogen to the present invention is to widen the heat treatment temperature range in the heat treatment process for producing this kind of excellent oily alloy, and does not directly contribute to the refinement of the crystal.

The Fe-based soft magnetic alloy according to the present invention can be obtained by the following method: After obtaining a thin strip of amorphous alloy by the liquid quenching method, the temperature is 50 ° C lower than the crystallization temperature of the above-mentioned amorphous alloy, preferably 120 ° C higher. The desired microcrystals are precipitated by heat treatment at a temperature from 30 ° C lower than the crystallization temperature to 100 ° C higher for 1 minute-10 hours, preferably 10 minutes-5 hours.

In manufacturing the alloy of the present invention, the reason for limiting the predetermined heat treatment temperature range and heat treatment time is that the soft magnetic properties such as FeB ₂ if the heat treatment temperature is too high or the heat treatment time is too long. Since the phase which becomes a factor which inhibits the precipitation precipitates, the value which has a predetermined | prescribed width | variety with respect to crystallization temperature is restrict | limited.

In addition, the liquid quenching method can be used to control the quenching rate and directly deposit the microcrystals.

If the micelle crystal grains in the alloy of the present invention are too small, that is, if there are too many amorphous phases, the iron loss becomes large, the magnetic permeability decreases, the magnetostriction increases, and the deterioration of the magnetic properties due to resin molding increases. .

The micelle crystal grains in the alloy are preferably present in an area ratio of at least 30%, more preferably at least 40%, even more preferably 50% or more.

In addition, if the size of the microcrystalline particles is too small, the maximum improvement of the magnetic properties will not be achieved, and if too large, the magnetic properties will be deteriorated.

Therefore, it is preferable that at least 80% of the microcrystalline particles consist of crystals having a crystal grain size of 50-300 mm 3.

The reason for limiting the area ratio of the microcrystalline particle diameter and the microcrystalline particle size as described above is that the soft magnetic properties such as iron loss and permeability depend on the microcrystalline particle size. For example, the dielectric constant (μ 1 _KHz ) and iron loss at 1 kHz, which are soft magnetic properties, change as the amount of Nb content (X) of the alloy Fe _76-X Cu ₁ Nb _X Si ₁₃ B ₆ N ₂ is changed. Fig. 3 shows how the shape depends on the particle diameter of the microcrystalline particles.

TABLE 4

As apparent from these tables, the magnetic properties are improved as the crystal grains become finer. In addition, the magnetic distortion is not reduced due to miniaturization alone, but the precipitated bcc-Fe solid solution is a factor. For example, when the quenched sample and the sample heat-treated at 520 ° C. were measured using a strain gauge, the magnetic strain was reduced by 2.1 ppm and 1.2 ppm, respectively. Can be.

Fe-based soft magnetic alloy of the present invention is excellent in soft magnetic properties at high frequencies. Examples include magnetic heads, thin film heads, high frequency transformers with high power transformers, saturable reactor common mode choke coils, normal mode choke coils, high voltage pulse noise filters and magnetic switches used in laser power supplies, It is an alloy for magnetic materials for magnetic parts such as magnetic cores used at high frequencies and for various sensors such as power sensors, orientation sensors and security sensors, and shows excellent characteristics.

EXAMPLE

A thin strip of amorphous alloy having a thickness of 15 μm was obtained from the alloy containing Fe ₇₄ Cu ₂ Mo ₂ Si ₁₁ B ₉ N ₂ by a single roll method.

Next, the amorphous alloy was wound to form a toroidal magnetic core having an outer diameter of 18 mm, an inner diameter of 12 mm, and a height of 4.5 mm, and then heat-treated at about 55 ° C. for about 90 minutes.

The crystallization temperature of this alloy was 575 degreeC at the temperature increase rate of 10 degree-C / min (measured by the temperature increase rate of 10 degree-C / min).

Microcrystalline particles in the range of about 85% were present with respect to the total area of the alloy in the obtained magnetic core, among which 50-300 microns of the microcrystalline particles were about 90%.

In addition, for comparison, a heat treatment was performed at about 450 ° C. for about 40 minutes to prepare a magnetic core.

As a result of observing the magnetic core obtained by TEM, microcrystalline particles did not precipitate in this magnetic core.

Comparing five samples of magnetic cores according to the present invention with microcrystalline particles and five comparative samples of magnetic cores without microcrystalline particles, iron loss after heat treatment at 100 kHz and 2 kG and epoxy coating Later iron loss, magnetostriction, permeability and saturation magnetic flux density at 1 kHz and 2 mOe were measured, and the average is shown in Table 5.

TABLE 5

As is apparent from Table 5, the alloy of the present invention has fine crystal grains, low iron loss after resin molding, high permeability, and magnetostriction, as compared with iron cores containing amorphous thin strips of the same composition. It is low and shows excellent performance of the smoker at high frequency.

The iron loss of the magnetic core of the alloy composition described above was measured using various heat treatment temperatures at 100 kHz and 2 kG using a U-function meter, and the results are shown in FIG.

For comparison, the same measurement was carried out with a magnetic core manufactured by the same method of Fe ₇₄ Cu ₂ Mo ₃ S ₉ B ₁₂ without containing N, and the result is shown in FIG.

By adding N, it was evident that the alloy of the present invention expanded the heat treatment temperature range in which iron loss was reduced.

As the alloy of the present invention, there is provided a Fe-based soft magnetic alloy having excellent soft magnetic properties, having fine crystal grains in a desired alloy composition and having a high saturation magnetic flux density in a high frequency region, and extending the heat treatment temperature range to provide a desired Fe group. The soft magnetic material can be easily produced.

The present invention is not limited to the above description and examples.

It is a matter of course that those skilled in the art may make the specific embodiments and modifications described above without departing from the spirit of the invention.

Claims (17)

Has microcrystalline particles, and among these microcrystalline particles, 50 microns to 300 microns, microcrystalline particles are present in the alloy at least 30% by area ratio Fe _100-abcd M _a M ' _b Y _c N _d Fe-based soft magnetic alloy, characterized in that. (M is at least one element selected from the group consisting of Cu, Ag, Au, Zn, Sn, Pb, Sb and Bi, and M 'is a group of elements IVa, Va, and VIa on the periodic table, Mn, Co, Ni and Al At least one element selected from the group consisting of Y and at least one element selected from the group consisting of Si, P and B 0.01≤a≤5 (at.%) 0.1≤b≤10 15≤c≤28 0 <d≤8 to be.) The Fe-based soft magnetic alloy according to claim 1, wherein at least 80% of the microcrystalline particles are in the range of 50 kPa-300 kPa. The Fe-based soft magnetic alloy of claim 1, wherein ＂M＂ is present in the range of 0.01-5 at.%. The Fe-based soft magnetic alloy of claim 1, wherein ＂M＂ is present in the range of 0.5-3 at.%. The Fe-based soft magnetic alloy of claim 1, wherein ＂M＂ is present in the range of 0.1-10 at.%. The Fe-based soft magnetic alloy of claim 1, wherein ＂M＂ is in the range of 1-7 at.%. The Fe-based soft magnetic alloy of claim 1, wherein ＂M＂ is present in the range of 1.5-5 at.%. The Fe-based soft magnetic alloy of claim 1, wherein the amount of YY is in the range of 15-28 at.%. The Fe-based soft magnetic alloy of claim 1, wherein the amount of YY is in the range of 18-26 at.%. The Fe-based soft magnetic alloy according to claim 1, wherein the ratio of Si / B or the ratio of Si / P is at least one. The Fe-based soft magnetic alloy according to claim 1, wherein the amount of nitrogen is 8 at% or less. The Fe-based soft magnetic alloy according to claim 1, wherein the amount of nitrogen is 6 at% or less. The Fe-based soft magnetic alloy according to claim 1, wherein the amount of nitrogen is 4 at% or less. Comprising the Fe-based soft magnetic alloy according to claim 1 to heat the crystallization temperature of the alloy at a temperature of 50 ℃ lower than the crystallization temperature from 120 ℃ high temperature for 1 minute-10 hours to precipitate microcrystalline particles Fe-based soft magnetic alloy manufacturing method characterized in that. 15. The method of claim 14, wherein the alloy is heat treated for 10 minutes-5 hours. The Fe-based soft magnetic alloy according to claim 1, wherein 40% of the fine particles are present in the range of 50 kPa-300 kPa. The Fe-based soft magnetic alloy of claim 1, wherein 50% of the fine particles are present in the range of 50 kPa-300 kPa.

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