KR19980073499A - Fe-based amorphous soft magnetic material and manufacturing method thereof - Google Patents

Abstract

The present invention relates to an Fe-based amorphous soft magnetic material and a method of manufacturing the same, and more particularly to a Fe-Zr-B soft magnetic amorphous alloy which forcibly alloys a non- By separating the non-solid-state atoms, fine clusters can be uniformly dispersed in an amorphous matrix. By thus having high permeability, authorsity, low coercive force and high resistance characteristics, which exceed the properties of existing amorphous materials, And it is possible to substitute the expensive Co-based soft magnetic alloy which is used with the Fe soft magnetic alloy which is suitable for mass production and production automation and is rich in ductility.

Description

Fe-based amorphous soft magnetic material and manufacturing method thereof

The present invention relates to an Fe-based amorphous soft magnetic material and a method of manufacturing the same, and more particularly, to a method of forging an Fe-Zr-B soft magnetic amorphous alloy by forcibly alloying non- The present invention relates to an Fe-based amorphous soft magnetic material and a method for manufacturing the same, wherein the fine magnetic clusters are uniformly dispersed in an amorphous matrix by phase separation of non-solid atoms.

Magnetic materials used as transformers and components of electric and electronic devices are one of the indispensable materials.

Among these materials, metal magnetic materials and ceramic magnetic materials such as ferrite are the most widely used, but magnetic materials having different characteristics are required depending on the use thereof.

It is needless to say that recent advanced electric and electronic devices are becoming increasingly smaller and lighter, and in order to achieve this, it is necessary to miniaturize a power source occupying about 40% of the total volume of the device.

In order to downsize the power source, it is necessary to make the operating frequency of the power source high-frequency, and it is necessary to make the magnetic materials used in the power source stable in high frequencies.

The most important characteristic of the magnetic material used in the device is the loss characteristic. Metal has a great difficulty in using as a magnetic material because it tends to increase the loss due to the skin effect in the high frequency band.

When the direct current flows through the conductor, the current flows through the conductor without change. However, when the AC flows, the change of the magnetic flux around the center becomes larger as the AC flows. As a result, the back electromotive force due to the change becomes large, Since the current flows almost only on the surface, the resistance is increased as the cross-sectional area is effectively reduced.

For this reason, ferrite (ceramic), a ceramic magnetic material, has been widely used in the hundreds of Khz bands.

This is because the eddy current loss does not occur because ferrite is an insulator that does not conduct electricity.

However, since ferrite has a very low magnetic flux density, it has a disadvantage in that it has a disadvantage in that it needs to have a large size in order to increase the output thereof.

An amorphous soft-magnetic material has attracted much attention as a material that can reinforce the above problems and can be used in a relatively high frequency band.

There are various methods for producing the amorphous soft magnetic material, but the most practical one at present is the liquid quenching method which solidifies the liquid at about 1 million degrees Celsius per second.

In this method, a thin ribbon-like thin plate is formed and then wound to make an amorphous soft magnetic material such as a toroidal core.

There are two conventional methods for producing an amorphous soft magnetic alloy, namely, a method using an amorphous single phase microstructure and a method using an ultra fine grain deposited by crystallizing an amorphous alloy.

The method using the amorphous single phase microstructure is a method of removing the residual stress introduced during the quenching by the liquid quenching method by preparing the amorphous ribbon by the liquid quenching method and then heat-treating the amorphous ribbon at an appropriate temperature. A magnetic field heat treatment method which applies a magnetic field from the outside during the heat treatment and a heat treatment method which does not apply a magnetic field in order to align the alignment of the magnetic domain in a desired direction.

The method using ultrafine grains is a method applied to the Fe-Cu-Nb-Si-B system. The amorphous ribbon produced by the liquid cooling method or the like is heat-treated at a temperature higher than the crystallization temperature to form a fine bcc lattice structure and a large amount of an α-Fe phase is precipitated.

However, in the case of using the microstructure of the amorphous single phase, there is a lot of room for improvement in terms of rich ductility and magnetic properties, and in the case of using ultrafine grains, about 80% or more And the remaining 20% remains in the crystalline interface due to the amorphous state. As a result, the material itself becomes very fragile, so there is a problem in the automation of the production line in mass production of the product. Not only is it necessary but also requires further improvement in the investment rate.

Also, an important point is price competitiveness of materials. Currently, Fe and Co-based amorphous alloys are widely used as soft magnetic materials.

Fe amorphous alloys have a high saturation magnetic flux density and low loss characteristics in a commercial frequency band. In the case of a Co-based amorphous alloy, it has a high permeability characteristic and a low loss characteristic in a high frequency band.

Therefore, the Fe-based amorphous alloy is mainly used in the low-frequency band and the Co-based amorphous alloy is used in the high-frequency band.

As described above, in order to meet the recent miniaturization of electric and electronic devices, magnetic parts such as a transformer and a reactor must be downsized in a power source for driving the electric parts.

That is, the need for a high permeability material having high saturation magnetic flux density characteristics and excellent frequency characteristics has been increasing with the tendency of miniaturization and high frequency of the noise filter for radio wave and the like.

As the amorphous alloy material satisfying such conditions, the Co-based material is more advantageous than the Fe-based material. This is because the Co-based amorphous alloy has a high permeability characteristic and a low loss characteristic in a high frequency band as described above.

In other words, the Co-based material has a higher saturation magnetization value than that of ferrite and has a higher natural resonance frequency than the ferrite-based material. Therefore, it is advantageous as a high-permeability material and the resistivity is 2 to 3 times higher than permalloy and electric steel sheet. It is possible to expect low wire loss even in the high frequency range.

However, since Co elements are 50 times more expensive than Fe elements and their reserves are very small worldwide, there are many limitations on the supply and demand of raw materials. Therefore, there are many problems in expanding the application range of Co-based amorphous alloys.

The present invention has been made to solve the above problems and it is an object of the present invention to provide a Fe-Zr-B alloy which is suitable for mass production and production automation of a Co-based soft magnetic alloy, A non-solid element which is not solved in Fe in a soft magnetic amorphous alloy is forcibly alloyed in the production of a parent alloy and then heat-treated to be phase-separated between Fe atom and non-solid atom to uniformly disperse a fine cluster structure of 2 to 3 nm in an amorphous matrix The present invention also provides an Fe-based amorphous magnetically soft material having improved magnetic properties by having a microstructure formed thereon.

1 is a graph showing changes in the coercive force characteristics of the amorphous soft magnetic alloy according to the heat treatment temperature of the present invention

2 is a graph showing the change of the saturation magnetic flux density according to the heat treatment temperature of the amorphous soft magnetic alloy of the present invention

3 is a graph showing changes in the initial permeability at a frequency of 1 kHz with the annealing temperature of the amorphous soft magnetic alloy of the present invention

4 is a graph showing changes in magnetization according to the heat treatment temperature of the amorphous soft magnetic alloy of the present invention

5 is a graph showing the change in electrical resistance of the amorphous soft magnetic alloy according to the heat treatment temperature of the present invention

FIG. 6 is a graph comparing the characteristics of the loss of the amorphous soft magnetic alloy of the present invention and other soft magnetic alloys according to frequency

Best Mode for Carrying Out the Invention Hereinafter, embodiments of the present invention and effects thereof will be described with reference to the accompanying drawings.

First, the manufacturing method of the present invention will be described. The amorphous ribbon is prepared by adding a proper amount of non-solid element as an additive element to the Fe-based amorphous alloy composition to quench the dissolved liquid, Annealed at an appropriate temperature to obtain a soft magnetic material having a microstructure in which nano-sized cluster particles are uniformly formed in an amorphous matrix, thereby obtaining an Fe-based amorphous soft magnetic material which can be used in a high frequency band.

At this time, the non-solid element facilitates the formation of nano-sized clusters by rejecting Fe atoms when crystallizing the amorphous ribbon by heat treatment.

As a method of manufacturing the amorphous ribbon, conventional quenching methods can be applied. Typically, a liquid quenching method is applied to a liquid in which a non-solid element is mixed with a metal melt as much as possible at a melting point of 1 million degrees Celsius To accelerate the employment of non-employment elements to the maximum extent possible.

In addition, the above-mentioned heat treatment process also includes the purpose of removing the residual stress introduced during the production of the amorphous ribbon. In this method, stress relaxation is performed and the alignment of the magnetic domains is aligned in a desired direction. It is possible to apply the heat treatment method among the magnetic field which applies the magnetic field from the outside and the heat treatment method without the magnetic field.

As described above, when dissolving the metal, the dissolving liquid in which the non-solid element is mixed with the metal melt as much as possible is rapidly quenched to promote the solidification of the non-solid element to a maximum extent, followed by heat treatment to induce a phase separation phenomenon with the Fe element, As a result, an amorphous soft magnetic material having a cluster microstructure of several nm in size can be manufactured.

The Fe-based amorphous soft magnetic material produced by the above method has the following characteristics.

Firstly, since the Fe-based amorphous soft magnetic material is finely and uniformly dispersed into the second phase in an amorphous matrix, the electrical resistance of the material is increased, and the eddy current loss of the magnetic body can be reduced Secondly, the magnitude of the ferro-magnetic domain of the amorphous soft magnetic material is significantly reduced, which can also reduce the eddy current loss. Thirdly, due to the nature of the Fe-based amorphous alloy, In the high-frequency region, the permeability is rapidly decreased and the loss is increased. However, since the cluster of several nm is finely dispersed, the magnetostriction is reduced to a value close to zero to greatly decrease the coercive force and exhibit a very high permeability characteristic Excellent soft magnetic characteristics are obtained. The superior soft magnetic properties are basically the lower the coercive force is, and the higher the permeability, the better.

Fourth, since the base is in an amorphous state, the ductility of the material is very abundant and the probability of breakage is low, so that automation by mass production is possible.

[Example]

Hereinafter, the present invention will be described more specifically by way of examples.

In this embodiment, Fe-Zr-B series is used as the Fe amorphous alloy, and Ag is used as the non-solid element.

First, an amorphous ribbon is prepared by using a liquid quenching method and a heat treatment is performed by adding a suitable amount of Ag, which is a non-solid element, as an additive element to the Fe-Zr-B based amorphous alloy composition, Based alloy that can be used in a high-frequency band to obtain an Fe-based amorphous alloy, and the composition range of each element is

Fe: 80 to 90 (%)

Zr: 3 to 10 (%)

B: 3 to 10 (%)

Ag: 0.1 to 1 (%)

.

When the Fe element is 80% or less, the amount of the magnetic element contained in the alloy is too small to obtain a large saturation magnetic flux density. This is because the magnetism This is because the saturation magnetic flux density of the material usually depends on the amount of the element having magnetic moment.

When the Fe element is 90% or more, a certain amount of an element that forms amorphous well during quenching of the liquid (hereinafter referred to as an amorphous forming element) is smoothly obtained. When Fe is added by 90% or more, It becomes difficult to obtain an amorphous phase.

In the case of the Zr component, an appropriate amount of the Zr component is suitably about 3 to 10%, and when the composition is out of the range, the magnetic properties tend to deteriorate.

In the case of element B, a suitable amount of the amorphous forming element is suitably about 3 to 10% as an element representative of the amorphous forming element. Addition of an appropriate amount of this element promotes the formation of amorphous phase, but if too much is added, ₂ B, and the like), thereby weakening the amorphous ribbon and not affecting the magnetic properties.

Good quality amorphous ribbons were formed in the range of 0.1 ~ 1% of the non-solid element Ag as an additive element, but 1% or more of Ag was not added in the production of the amorphous ribbon.

The Fe _87.3 Zr _5.9 B _6.5 Ag _0.3 alloy, which is a part of the Fe-based amorphous soft magnetic material prepared on the basis of the above-mentioned points, will be described as an embodiment.

The Fe-Zr-B-Ag parent alloy was prepared by arc melting the Fe-Zr-B-Ag parent alloy in an Ar atmosphere in the above-mentioned element ratio (Fe: 87.3%, Zr: 5.9%, B: 6.5%, Ag: 0.3% An amorphous ribbon having a width of 2 mm and a thickness of 30 탆 was prepared by using a single roll melt spinning apparatus in an Ar atmosphere in an amount of about 5 g of the mother alloy obtained here. The ribbon was annealed at 200 ~ 600 ℃ for 1 hour under vacuum and then furnace cooled to prepare amorphous soft magnetic material of Fe _87.3 Zr _5.9 B _6.5 Ag _0.3 .

The characteristics of the Fe _87.3 Zr _5.9 B _6.5 Ag _0.3 amorphous soft magnetic material prepared by the above method are shown in the accompanying drawings. FIG. 1 is a graph showing the coercive force (Mn) of the Fe _87.3 Zr _5.9 B _6.5 Ag _0.3 alloy according to the heat treatment temperature H _c ), which is much smaller than that of the existing Fe-Zr-B series, that is, excellent coercive force characteristics can be obtained at a heat treatment temperature of about 400 ° C. and about 15 mOe.

This is because the Fe ₈₉ Zr ₇ B ₄ alloy reported by Suzuki et al. [K. Suzuki, N. Kataoka, A. Inoue, A. Makino, T. Masumoto; Materials Transactions JIM, Vol. 31, No. 8 (1990), pp. 743 to 746] is much smaller than the coercive force of 93 mOe.

FIG. 2 shows changes in magnetic flux density (B ₁₀ ) at an external applied magnetic field of 10 Oe according to the annealing temperature of Fe _87.3 Zr _5.9 B _6.5 Ag _{0.3. As the} annealing temperature increases, the magnetic flux density gradually increases, Lt; RTI ID = 0.0 > C, < / RTI > A magnetic flux density of 1.2 T was obtained at the heat treatment temperature of 600 ° C, which was completely crystallized.

FIG. 3 shows changes in the initial permeability (μi) of the Fe _87.3 Zr _5.9 B _6.5 Ag _0.3 alloy at a frequency of 1 kHz and 3 mOe according to the annealing temperature. The annealing temperature sharply increases up to 400 ° C., And a maximum value of 287,000 was obtained at a heat treatment temperature of 400 ° C.

It should be noted that the maximum permeability at a heat treatment temperature of 400 ° C is far superior to that of other conventional materials. It can be seen that this value is about 19 times higher than the value of 15,900 (= μe) of the Fe ₈₉ Zr ₇ B ₄ alloy reported by Suzuki et al. Mentioned above.

In other words, this means that the Fe-based amorphous material can be used in a high frequency band to overcome the disadvantage that the application range of the Fe-based amorphous material is restricted to the low-frequency region, and thus the value that has been used as the high- It can be said that it is a breakthrough that can replace Co with a small amount of reserves.

FIG. 4 is a graph showing the magneto-resistive property (λ _s ) closely related to the magnetic permeability characteristic in order to investigate the cause of the ultra high permeability characteristic as described above. In the as-quenched material, ), And then gradually decreased to 350 ° C. as the heat treatment temperature was increased. After the heat treatment temperature was reduced to 400 ° C., the temperature was decreased to 500 ° C. and then increased to 500 ° C. At the annealing temperature of 550 ℃, it decreased sharply again to show the negative jerk value and the jerk value again at 600 ℃.

From the figure, it can be seen that a magnetostriction of 0 was obtained at a heat treatment temperature of about 540 ° C. and a very low value of about 1.89 × 10 ^-6 at a heat treatment temperature of 400 ° C. at which a high permeability characteristic was obtained was obtained. It can be seen that the smaller the magnitude of the magnetostriction is, the higher the permeability characteristic is, and the higher permeability characteristic of the present invention is attributed to the lower magnetostriction property.

FIG. 5 is a _graph showing the change in electrical resistance of the Fe _87.3 Zr _5.9 B _6.5 Ag _0.3 alloy according to the heat treatment temperature. Since the electrical resistance is one of the most sensitive properties depending on the microstructure of the material, It is a very useful method to identify

In the as-quenching state, the resistivity was 1.23 μΩm. The resistivity decreased slightly to 350 ° C. and then increased sharply to 400 ° C., reaching a maximum value of 1.36 μΩm, and then decreased as the annealing temperature increased .

The electrical resistivity values at 400 ° C are the same as those of the conventional Fe-Zr-B amorphous alloy [T.K. KIM, S. Ishio, M. Takahashi: Proc. 4th Inter. Conf. , which is very high when compared with the on Rapidly Quenched Metals, Vol.2 (edited by T. Masumoto and K. Suzuki, The Japan Institute of Metals, Sendai, Japan, 1982, p. 1323) This is because the eddy current loss tends to decrease with an increase in the electric resistance of the material, thereby reducing the eddy current loss in the high frequency range.

Here, it should be noted that the resistivity increases sharply at a heat treatment temperature of 400 ° C. The fact that the resistivity increases sharply under these microstructures shows that the amorphous state of the microstructure at the heat treatment temperature of 400 ° C is still very fine It reflects the fact that clusters are formed and dispersed.

These facts are very meaningful. Researches on amorphous materials so far have aimed at the amorphous single phase in which the clusters of the second phase are not formed, and those in which the amorphous phase is generated in a state of As-quenching, Unlike the precipitation of fine grains by heat treatment, a new research field is proposed to form fine clusters in the amorphous phase matrix.

FIG. 6 shows loss characteristics of Fe _87.3 Zr _5.9 B _6.5 Ag _0.3 alloy according to frequency of a sample annealed at 400 ° C. For comparison, Co ₆₉ Fe _3.8 Si _12.9 B _10.5, which is widely used as a high frequency amorphous material, Cr _3.8 .

As can be seen from the figure, the loss characteristic exhibits almost no difference compared with the Co-based amorphous alloy.

At the frequency of 100 kHz, the loss values of the Co system and the present invention were respectively 40 W / kg and 50 W / kg, which shows that the present invention can sufficiently replace the Co-based amorphous material.

In addition, one particular characteristic is that the material is rich in ductility capable of bending at 180 ° after heat treatment at a heat treatment temperature of 400 ° C, which overcomes the disadvantage that existing amorphous materials become vulnerable after heat treatment. There is no difficulty in the handling of the product, and it is very advantageous for mass production and automatic production.

The effect obtained by the present invention as described above is expected to have a low loss property even in a high frequency band because it has a high permeability, authorsity, low coercive force, and high electric resistance characteristics which far exceed the characteristics of existing amorphous materials. Can be used as a core material (supersaturated core, choke core, noise filter, transformer, and the like) from a low frequency band to a high frequency band of several hundreds of kHz as well as overcoming the disadvantage that conventional amorphous materials become vulnerable after heat treatment. There is no difficulty in the manufacturing process and the handling of the product, which is very advantageous for mass production and automatic production.

Claims (5)

Wherein the Fe-based amorphous soft magnetic material has a Fe _? Zr _? B _? Ag _? (?: 80 to 90,?: 3 to 10,?: 3 to 10,?: 0.1 to 1) composition. The amorphous alloy is prepared by adding an appropriate amount of non-solid element as an additive element to the Fe-based amorphous alloy composition to quench the dissolved liquid to prepare an amorphous ribbon, and then heat-treating the alloy at an appropriate temperature to form a microstructure soft magnetic material Wherein the Fe-based amorphous soft magnetic material is produced in the form of an Fe-based amorphous soft magnetic material. The method according to claim 1, The present invention is characterized in that the non-solid element is mixed with the molten metal as much as possible during the melting of the metal by quenching at a speed of about 1 million degrees Celsius per second by applying the liquid quenching method by the quenching method to maximize the employment of the non- Method for manufacturing an Fe - based amorphous soft magnetic material. The method according to claim 1, In order to relax the stress during annealing and to arrange the magnetic domains in the desired direction, a heat treatment method in a magnetic field which applies a magnetic field from the outside during the heat treatment or a heat treatment method without applying a magnetic field is additionally applied Wherein the Fe-based amorphous soft magnetic material is a Fe-based amorphous soft magnetic material. The method according to claim 1, Amorphous ribbon and an iron-based amorphous soft magnetic material characterized by arc melting in an Ar atmosphere to prevent oxidation during rapid cooling and cooling after production.