KR20170082468A - Method for manufacturing Fe based soft magnetic alloy - Google Patents

Abstract

A method of producing an Fe-based soft magnetic alloy is provided. The Fe-based soft magnetic alloy according to an embodiment of the present invention is represented by an empirical formula Fe _a B _b C _c Cu _d where a, b, c, and d are atomic percentages of the corresponding element, and 78.5 ? A? 86, 13.5? B + c? 21, and 0.5? D? 1.5. And heat-treating the Fe-based initial alloy. According to this method, the manufacturing cost can be greatly reduced because expensive alloying components are not used, and the components contained in the alloy are easily controlled in the course of manufacturing the alloy, which is advantageous for mass production since it is easy to manufacture. In addition, since a uniform and small-diameter crystal can be produced through a post-process, high-level magnetic properties can be exhibited. Furthermore, the Fe-based alloy produced has a high saturation magnetic flux density, excellent high-frequency characteristics and low coercive force, making it very easy to develop into a compact / lightweight component with high performance / high efficiency, High frequency filter, low loss high frequency transformer, high speed switch, wireless charging, and the like.

Description

FIELD OF THE INVENTION [0001] The present invention relates to a method for manufacturing a soft magnetic alloy,

More particularly, the present invention relates to a method for producing an Fe-based soft magnetic alloy capable of producing an Fe-based soft magnetic alloy exhibiting a high saturation magnetic flux density and a low magnetic loss .

Soft magnetic materials are magnetic materials for various kinds of transformers, choke coils, various sensors, saturable reactors, magnetic switches and so on. They are used for various electric and electronic devices . Market demands for such electric and electronic devices are small and lightweight, high performance / high efficiency, and low product price. To meet this market demand, soft magnetic materials for magnetic cores should have high saturation flux density and low magnetic loss. Specifically, the output of the magnet core type voltage (E) = the magnetic flux density (B _m) × 4.44 frequency (f) × number of turns (N) × may be calculated by the magnetic core cross-sectional area (S), in order to increase the voltage (E) Each factor should be high. Of these factors, magnetic flux density (Bm) and frequency (f) depend on the magnetic material of the magnetic core. To increase the magnetic flux density, a material having a high saturation magnetic flux density and a low magnetic loss is required. The magnetic loss is calculated as the sum of hysteresis loss, eddy current loss and anomaly loss. In the case of the eddy current loss and the anomaly loss, it depends on the size of the magnetic core of the magnetic core material, the resistivity and the thickness of the magnetic core, The higher the thickness of the magnetic core, the better the magnetic loss. Further, in order to increase the frequency, the high frequency loss of the magnetic material should be small. However, since a circuit approach is required to raise the frequency f, there is a limit to the material approach.

On the other hand, an amorphous alloy containing Fe, which is known as a commercially available magnetic material having a high saturation magnetic flux density and a low loss at the same time, does not have crystal grains and therefore has no magnetocrystalline anisotropy and a low hysteresis loss And exhibits excellent soft magnetic properties, amorphous alloys containing Fe are attracting attention as energy saving materials.

The Fe-containing amorphous alloy is an element which forms an alloy. In addition to Fe, elements such as Si, B, and P that enhance the amorphous forming ability and elements such as Cu, Nb, and Zr elements serving as diffusion barriers and / (metalloid). However, there is a problem that the saturation magnetic flux density of the alloy is lowered when the content of the metalloid is increased, and when the content of the metalloid is decreased, the initial alloy is not formed as an amorphous state or the post- (Heat treatment), it is difficult to control the crystal size, so that the coercive force and magnetic loss may increase. The Fe-based amorphous alloy containing P, which is known to improve the amorphous forming ability, is easily volatilized in the post-process for changing the characteristics, It is very difficult to carry out the post-treatment, and the productivity of the alloy is remarkably lowered in the post-process, which may be very disadvantageous to mass production.

In addition, when B, which is known to have amorphous ability, is contained, the gap between the primary crystallization temperature and the secondary crystallization temperature of the produced alloy becomes very narrow, so that, in post-treatment, B) is generated and it is difficult to obtain a homogeneous crystal of? -Fe. In addition, when a rare metal such as Nb is added, there is a problem that the production cost is remarkably increased as the unit price of the element is high, although it is advantageous in controlling the grain size control in the subsequent step.

KR 1988-0073499A

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and it is an object of the present invention to provide a ferromagnetic soft magnetic alloy which is easily controlled in the manufacturing process, Or more of the Fe-based soft magnetic alloy.

Another object of the present invention is to provide a method for producing an Fe-based soft magnetic alloy capable of controlling a crystal phase, even though it does not contain a high-cost component such as a rare-earth element.

Further, the present invention provides an Fe-based soft magnetic alloy which has a high saturation magnetic flux density and excellent high-frequency characteristics and can be utilized as a component that is reduced in size and weight, has low magnetic loss such as low coercive force, And a method for producing the same.

In order to solve the above-mentioned problems, the present invention is represented by the empirical formula Fe _a B _b C _c Cu _d where a, b, c and d are at% (atomic percent) , 13.5? B + c? 21, and 0.5? D? 1.5. And a step of heat-treating the Fe-based initial alloy.

According to an embodiment of the present invention, a is 82 to 86 at% in the empirical formula, b and c are in the range of 13.5 to 17.5 at%, and the value according to the following formula 1 may be 0.38 to 28.5. More preferably, the value according to the following formula (1) may be 0.65 to 16.1.

[Equation 1]

In the empirical formula, a and d may have a value according to the following equation (2): 2.92 to 3.70.

&Quot; (2) "

In the empirical formula, c may be 1.0 to 4.0 at%.

According to another embodiment of the present invention, in the empirical formula, a is less than 78.5 to less than 82.0 at%, b and c are more than 16.5 at% to 21 at%, and the value of the following equation , And more preferably 0.85 to 200.

&Quot; (3) "

Also, in the empirical formula, the values of a and d may be 8.3 to 12.8.

&Quot; (4) "

The Fe-based soft magnetic alloy having the heteroatom array structure may have an amorphous region and a crystalline region in a volume ratio of 5.5: 4.5 to 1: 9.

In addition, the heat treatment may be performed at a heat treatment temperature of 200 to 410 캜 for 40 to 100 seconds, more preferably at a heat treatment temperature of 280 to 410 캜.

Further, the heat treatment can be performed at a heating rate of 90 ° C / min or less up to the predetermined heat treatment temperature, more preferably 28 to 82 ° C / min.

The prepared Fe-based soft magnetic alloy may have a crystallized area value of 45 to 90% according to the following relational expression 1, more preferably a crystallized area value of 53 to 83%.

[Relation 1]

Here, the area refers to the integral value of the crystalline region or amorphous region measured by X-ray diffraction (XRD) analysis at 0 to 90 ° angle (2?) With respect to the Fe-based soft magnetic alloy.

.

Hereinafter, terms used in the present invention will be described.

As used herein, the term "initial alloy" refers to an alloy in which a process such as heat treatment is not performed for the purpose of changing the properties of the alloy produced.

As used in the present invention, "high frequency" means a frequency band of several tens of kHz to several tens of MHz.

According to the present invention, the manufacturing cost is greatly reduced because expensive alloy components are not used, and the components included in the alloy are easily controlled in the course of manufacturing the alloy, which is advantageous for mass production since it is easy to manufacture. In addition, since a uniform and small-diameter crystal can be produced through a post-process, high-level magnetic properties can be exhibited. Furthermore, the Fe-based alloy produced has a high saturation magnetic flux density, excellent high-frequency characteristics and low coercive force, making it very easy to develop into a compact / lightweight component with high performance / high efficiency, High frequency filter, low loss high frequency transformer, high speed switch, wireless charging, and the like.

FIG. 1 and FIG. 2 show XRD patterns in an initial alloy state before annealing of Fe-based soft magnetic alloy according to various embodiments of the present invention,
FIG. 3 is a graph showing the XRD pattern of the Fe-based soft magnetic alloy according to the comparative example of the present invention in an initial alloy state before heat treatment,
FIGS. 4A and 4B illustrate XRD patterns after annealing of Fe-based soft magnetic alloy according to an embodiment of the present invention,
5A and 5B are graphs showing XRD patterns after annealing of Fe-based soft magnetic alloy according to another embodiment of the present invention,
6A and 6B are graphs showing XRD patterns after heat treatment of Fe-based soft magnetic alloy according to another embodiment of the present invention,
FIGS. 7A and 7B illustrate XRD patterns of Fe-based soft magnetic alloys after heat treatment according to another embodiment of the present invention,
8A and 8B are graphs showing XRD patterns after annealing of Fe-based soft magnetic alloy according to another embodiment of the present invention,
9A and 9B are graphs showing XRD patterns after annealing of Fe-based soft magnetic alloy according to another embodiment of the present invention,
10A to 10E are graphs showing VSM graphs of the Fe-based soft magnetic alloy in the initial alloy state before the heat treatment in the manufacturing process of various embodiments of the present invention,
11A to 11E are graphs of the VSM graph after heat treatment of the Fe-based soft magnetic alloy according to various embodiments of the present invention,
FIG. 12 is a graph showing a VSM graph after heat treatment of Fe-based soft magnetic alloy according to various embodiments of the present invention,
FIGS. 13A to 13C are graphs showing VSM graphs of Fe-based soft magnetic alloys according to various embodiments of the present invention,
14A to 14C are graphs showing VSM graphs of Fe-based soft magnetic alloys according to various embodiments of the present invention manufactured at different heating rates,
15A and 15B are TEM photographs of the Fe-based soft magnetic alloy according to an embodiment of the present invention.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings, which will be readily apparent to those skilled in the art to which the present invention pertains. The present invention may be embodied in many different forms and is not limited to the embodiments described herein.

The Fe-based soft magnetic alloy according to the present invention is manufactured by preparing an Fe-based initial alloy having an empirical formula according to the present invention in a first step, and then subjecting the Fe-based initial alloy prepared in the second step to heat treatment.

As a first step, the Fe-based initial alloy is represented by an empirical formula Fe _a B _b C _c Cu _d , where a, b, c, and d are at% (atomic percent) 13.5? B + c? 21, and 0.5? D? 1.5.

Before examining the concrete production method of the initial alloy, the empirical formula will be described.

First, the Fe is a main element of an alloy for expressing magnetism, and Fe is contained in the alloy at 78.5at% or more for the purpose of improving the saturation magnetic flux density. If the Fe content is less than 78.5 at%, the desired level of saturation flux density may not be achieved. If Fe is contained in the alloy in excess of 86.0 at%, it may be difficult to prepare the crystalline phase of the initial alloy at the time of quenching the liquid for the initial alloy production, The generated crystals interfere with uniform crystal growth in a heat treatment process for changing characteristics, and the magnetic loss may increase due to an increase in the coercive force as the size of generated crystals excessively increases.

Next, in the above empirical formula, B and C are amorphous forming elements. Through these elements, the initial alloy can be formed into an amorphous phase. In addition, the element C is combined with the element B, so that it is easier to control the particle size of the produced? -Fe crystal to a desired level compared with the case where only the element B is contained, and the thermal stability of the initial alloy is improved, There is an advantage in obtaining an? -Fe crystal. If the sum of element B and element C is less than 13.5 at% in the alloy, the initial alloy produced may be crystalline, and the crystals in the initial alloy make it difficult to uniformly grow the crystals produced during the heat treatment for the change in magnetic properties, Crystals with coarse grain size may be included, which may lead to an increase in magnetic loss. Further, when the sum of the C element and the B element in the alloy is more than 21 at%, the content of the Fe element in the alloy is relatively increased as the content of Cu element to be described later is increased in order to prepare the alloy of the nanocrystalline after the heat treatment And may thus fail to achieve the desired level of saturation flux density. Further, in addition to the? -Fe crystal, Fe easily forms a compound with B and / or C, and magnetic properties such as saturation magnetic flux density may decrease as the amount of the compound formed increases

Next, in the empirical formula, Cu is an element serving as a nucleation site capable of generating α-Fe crystals in an alloy, and thus an initial alloy of an amorphous phase is easily realized as a nanocrystalline alloy. The Cu element is an amorphous crystal phase of the initial alloy, and the crystal produced after the heat treatment is a nanocrystalline. The Cu element is contained in an amount of 0.5 to 1.5 at% in the alloy for remarkable expression of the desired properties, preferably 0.5 to 1.1 at%. If the Cu element is contained less than 0.5 at% in the alloy, the resistivity of the alloy to be produced may be greatly reduced, resulting in a large magnetic loss due to eddy currents, and the formation of α-Fe nanocrystals at the desired level in the heat- And the grain size control of the generated crystal may not be easy when crystals are generated. In addition, if the Cu element is contained in an amount exceeding 1.5 at% in the alloy, the crystalline phase of the prepared initial alloy may be crystalline, and crystals already produced in the initial alloy may cause the grain size of crystals produced during the heat treatment to be uneven, Crystals grown to a level greater than the level may be included in the alloy, which may result in an inability to exhibit the desired level of magnetic properties, such as increased magnetic loss. In addition, as the content of the above-mentioned Fe, B, and C elements is relatively decreased, the effect due to the element can be reduced.

On the other hand, the composition of the Fe-based soft magnetic alloy according to the present invention does not include the Si element contained in the usual Fe-based soft magnetic alloy. The Si element improves the amorphous forming ability of the Fe-based alloy and helps to equalize the particle diameters of the produced? -Fe crystals. However, when the Si is included in the alloy, there is a problem that the content of quasi metals other than Fe, for example, B, C and Cu, or the content of Fe must be decreased, and the content of Fe is decreased because of the high saturation magnetic flux density Of Fe-based alloys. Accordingly, the Fe-based alloy of the present invention does not contain Si but realizes high saturation density by increasing the content of Fe element. However, since the Si element is not included, it is very difficult to control the grain size of the crystal in the alloy, Which is not very easy to manufacture. In order to solve such a disadvantage, the present invention can produce an Fe-C compound at an appropriate level during the heat treatment of an initial alloy produced by appropriately adjusting the element B and element C according to the content of iron in the alloy, The grain size control of the? -Fe crystal can be achieved at a desired level even though the Si element is not included.

However, in the above empirical formula, the sum of contents of b and c may be different from that of the iron content a at 82 at%. When a is 82 at% or more, that is, a is 82 to 86 at% c has a sum of 13.5 to 17.5 at%, and a value according to the following formula 1 may be 0.38 to 28.5. In the empirical formula, when a is less than 82 at%, that is, a is less than 78.5 to 82.0 at%, the sum of b and c is more than 16.5 at% to 21 at%, and the value of the following formula 3 may be 0.67 or more.

First, in the above empirical formula, when a is 82 to 86at%, if a is 82 to 86at%, if the sum of b and c exceeds 17.5at%, the value of d, which is the content of Cu, Even if the prepared initial alloy is made into an amorphous phase, there is a fear that the produced initial alloy has a small particle diameter and hardly produces uniform crystals upon heat treatment, and the magnetic loss of the produced Fe-based soft magnetic alloy may become large.

In addition, when a is 82 to 86 at%, b and c may have a sum of 13.5 to 17.5 at% and a value according to the following formula 1 may be 0.38 to 28.5, It is advantageous to realize that a large saturation magnetic flux density is exhibited as the content of? -Fe among the crystals in the alloy produced after heat treatment and the intermetallic compounds formed between Fe and elements of at least one of B, C and Cu are appropriately controlled At the same time, magnetic loss such as coercive force is reduced and high-efficiency magnetic characteristics can be exhibited, and excellent magnetic characteristics can be exhibited at high frequencies.

[Equation 1]

If the value according to Equation (1) is less than 0.38, the crystalline phase of the prepared initial alloy may be crystalline, and in this case, a coarse crystal can easily be formed during the heat treatment, and the magnetic loss may become large. There is an increasing concern. Even if the initial alloy is not crystalline, the amount of Fe and C in the crystals produced after the heat treatment becomes excessively large, which may lead to a decrease in magnetic properties. If the value according to Equation (1) exceeds 28.5, the content of C is relatively decreased as compared with the content of B in the alloy, so that the thermal stability of the initial alloy is lowered. There is a problem that the control of the heat treatment process may be very difficult and the saturation magnetic flux density of the initial alloy or the alloy after the heat treatment may be decreased or the magnetic loss may be increased, it may be difficult to control the particle size of the? -Fe crystal to a desired level, so that it may not be possible to produce a magnetic material including an? -Fe crystal having a uniform particle size.

The value according to Equation 1 may be more preferably 0.65 to 16.1. If the value according to Equation 1 is less than 0.65, it may be impossible to form an amorphous phase, which may result in loss of characteristics of the soft magnetic material. have.

Also, when the value according to Equation 1 exceeds 16.1, it may be difficult to produce the initial alloy as an amorphous phase, and even when the initial alloy is realized as an amorphous phase, crystals produced after the heat treatment can be coarsened, You can lose traits.

Further, when a is 82 to 86 at%, the C element may be contained in an amount of 1 to 4 at% in the alloy. If the C element is contained in an amount of 1 at% or less in the alloy, it is difficult to produce the initial alloy as an amorphous phase. If the element B is increased, the secondary stability of the initial alloy may be lowered. In addition, it is difficult to control the particle size of the? -Fe crystal produced at the time of heat treatment of the produced initial alloy, so that a magnetic material having an α-Fe crystal having a uniform particle size can not be produced. Also, if the C element is contained in an amount exceeding 4 at% in the alloy, the content of B relatively decreases, so that an α-Fe crystal having a grain size of 30 nm or more in the initial alloy can be produced. There is a problem that it is difficult to control the particle size of the? -Fe crystal in the heat treatment step. In addition, an intermetallic compound between Fe and C may be produced in the initial alloy, so that the amount of the α-Fe crystal formed in the heat treatment may be less than the desired level. In addition, since the coercive force is increased and the magnetic loss is large, the desired level of magnetic properties can not be expressed, so that it may be difficult to apply the material as a miniaturized magnetic material.

Also, when a is 82 to 86 at%, the values a and d in the empirical formula may be 2.92 to 3.70 according to the following formula (2), whereby the initial alloy may be an amorphous phase, It is advantageous for the crystal to be a nanocrystal and to have a uniform particle size distribution. If the value according to the following formula (2) is less than 2.92, crystals are generated in the initial alloy, and it becomes difficult to obtain a uniform grain size determination after the heat treatment. Coarse crystals can be produced, And can not express the desired level of magnetic properties. When the value according to the following formula (2) is more than 3.70, the resistivity of the alloy to be produced is greatly reduced, and the magnetic loss due to the eddy current can be increased, and nano-grains of α-Fe are produced at desired levels in the heat- And the grain size control of the generated crystal may not be easy when crystals are generated.

&Quot; (2) "

Next, the case where a is less than 78.5 to 82.0 at% in the empirical formula will be described. When a is less than 78.5 to less than 82.0at%, the sum of b and c may be greater than 16.5at% to 21at%. If the sum of b and c is less than 16.5at%, the initial alloy may be crystalline, The crystals that have already been produced can cause the grain size of the crystals produced during the heat treatment to be uneven, and crystals grown to the desired level or larger can be included in the alloy, thereby exhibiting the desired level of magnetic properties I can not. In addition, as the content of the above-mentioned Fe, B, and C elements is relatively decreased, the effect due to the element can be reduced.

Further, the value of the following formula (3) may be 0.67 or more, more preferably 0.85 to 200, and the initial alloy produced thereby may be amorphous, and the grain size after the heat treatment may be uniform, The content of Fe and the content of the intermetallic compound between Fe and B or C can be appropriately maintained so that excellent magnetic properties can be exhibited through a low coercive force even if the Fe content is somewhat low.

&Quot; (3) "

If the value of Equation (3) is less than 0.67, the content of interfacial Fe-C compound in the initial alloy or the alloy after heat treatment may increase and it may be difficult to produce a crystal having a uniform particle size distribution after heat treatment, It is possible to lower the saturation magnetic flux density and / or to increase the coercive force, thereby deteriorating the magnetic characteristics. However, if the value of Equation (3) exceeds 200, the thermal stability of the initial alloy is lowered, and the generation of Fe-B intermetallic compounds in addition to the crystals of? -Fe may be significantly increased during the heat treatment, And there is a problem that the saturation magnetic flux density of the initial alloy or the alloy after heat treatment may be decreased or the magnetic loss may be increased, and it is difficult to control the particle size of the produced? -Fe crystal to a desired level It may be difficult to produce an? -Fe crystal having a uniform grain size.

Also, when a is less than 78.5 to 82.0 at%, the values of a and d in the empirical formula may be 8.3 to 12.8. As a result, the initial alloy may be an amorphous phase, and the crystals produced after the heat treatment of the initial alloy are advantageous to have nanocrystalline and uniform particle size distribution. If the value according to Equation (4) is less than 8.3, crystals may be generated in the initial alloy, and it is difficult to obtain a uniform grain size determination after the heat treatment, and coarsened crystals may be produced, May not be able to manifest the desired level of magnetic properties, for example, increase in thickness. Also, when the value according to Equation (4) is more than 12.8, even if the prepared initial alloy is made into an amorphous phase, the resistivity of the alloy to be produced may be greatly reduced, so that the magnetic loss due to the eddy current may become large. It is difficult to control the grain size of the produced crystals when the crystals are generated, so that it may be difficult to produce uniform crystals with a small particle size, and the resulting Fe-based soft magnetic alloy There is a concern that magnetic loss may become large.

&Quot; (4) "

The Fe-based initial alloy may be prepared by melting and then quenching and solidifying the Fe-based alloy-forming composition or Fe-based alloy-forming composition in which the base materials containing the respective elements are weighed and mixed so as to have the empirical formula of the Fe-based alloy. The shape of the Fe-based initial alloy produced according to the specific method used in the quenching and solidifying step may be changed. The method used for the quenching and solidifying can be carried out by a known method, so that the present invention is not particularly limited thereto. However, as a non-limiting example, the quenching and coagulation can be performed by a high-pressure gas (Ex. Ar, N ₂ , He, etc.) and / or high-pressure water through which molten Fe- A centrifugal separation method in which a powder phase is produced by using a disk rotating rapidly a molten metal, and a melt spinning method in which a ribbon is produced by a roll rotating at a high speed, and the like. The shape of the Fe-based initial alloy formed through these methods may be powder, strip, or ribbon. In addition, the atomic arrangement in the Fe-based initial alloy may be an amorphous phase.

On the other hand, the shape of the Fe-based initial alloy may be bulk. When the shape of the Fe-based initial alloy is bulk, the powder of the amorphous Fe-based alloy formed by the above-described methods can be made into a bulk amorphous alloy through a conventionally known method, such as a coalescing method and a coagulation method. Methods such as shock consolidation, explosive forming, powder sintering, hot extrusion and hot rolling may be used as a non-limiting example of the above coalescing method. In the impact-combining method, impact waves are transmitted along the particle boundary by applying shock waves to the powder alloy polymer, and energy absorption occurs at the particle interface. At this time, the absorbed energy forms a fine molten layer on the particle surface To produce a bulk amorphous alloy. The resulting molten layer should be cooled fast enough to maintain the amorphous state through heat transfer into the particles. With this method, a bulk amorphous alloy having a filling density of up to 99% of the original density of the amorphous alloy can be manufactured, and sufficient mechanical properties can be obtained. The hot extrusion and rolling method utilizes the fluidity of the amorphous alloy at a high temperature. The amorphous alloy powder is heated to a temperature near Tg, rolled, quenched after rolling, and thereby a bulk amorphous alloy having sufficient density and strength is manufactured .

On the other hand, the above solidification method may include copper mold casting, high pressure die casting, arc melting, unidirectional melting, squeez casting, strip casting, and the like And the respective methods may employ known methods and conditions, and thus the present invention is not limited thereto. For example, the copper alloy mold casting method uses a suction method in which a molten metal is injected into a copper mold having high cooling ability by using a pressure difference between the inside and the outside of the mold, A molten metal injected into a copper mold at a high speed by pressurization or suction is solidified by metal so that an amorphous Fe-based initial alloy having a predetermined bulk shape can be produced.

The Fe-based soft magnetic alloy according to one embodiment of the present invention may be amorphous or crystalline in crystalline phase, or may be a heteroatom array structure including both an amorphous region and a crystalline region.

At this time, the Fe-based soft magnetic alloy having the amorphous phase may be an initial alloy which is not heat-treated. The Fe-based soft magnetic alloy having the crystalline phase may be an alloy after heat-treating the initial alloy, and the crystalline phase may be a nanocrystal. The average grain size of the nanocrystalline grains is 30 nm or less, preferably 25 nm or less , More preferably 22 nm or less, and further preferably 16 to 22 nm. In addition, the heterogeneous atomic arrangement may be an initial alloy or a structure of an alloy after heat treatment. At this time, when the hetero atom array structure is in the initial alloy state, the crystalline compound may have a fine particle size with an average particle diameter of 10 nm or less. When the heterogeneous atomic arrangement is annealed and then alloyed, the crystalline phase may be nanocrystalline, and the average grain size of the nanocrystalline grains is 30 nm or less, preferably 25 nm or less, more preferably 16 to 22 nm or less .

When the Fe-based soft magnetic alloy according to an embodiment of the present invention has a heteroatom array structure, the amorphous region and the crystalline region may have a volume ratio of 5.5: 4.5 to 1: 9. If the amorphous and crystalline regions exceed the volume ratio of 5.5: 4.5 and more amorphous regions are present, the desired magnetic properties, such as the desired saturation flux density, may not be achieved. If the amorphous region and the crystalline region are less than 1: 9 volume ratio and the crystalline region is larger, crystal formation of the compound other than the [alpha] -Fe crystal may be increased and the desired magnetic property It can not be done.

The Fe-based soft magnetic alloy may be in the form of a powder, a strip, or a ribbon before the heat treatment, but may be suitably modified in consideration of the shape of the final magnetic material, the heat treatment process, and the like. The Fe-based soft magnetic alloy may have a shape after the heat treatment, such as a ribbon or a rod, and the cross-section of the rod may be polygonal, circular, or elliptical.

Next, as a second step according to the present invention, the Fe-based initial alloy is heat-treated.

The heat treatment is a step of transforming the atomic arrangement of the Fe-based initial alloy from amorphous to crystalline, and it is possible to produce nanocrystals including α-Fe through the heat treatment. However, since the size of the crystals generated according to the temperature, the heating rate and / or the treatment time, which is heat-treated in the second step, can be grown to the desired level or more, the control of the heat treatment conditions is very important in controlling the grain size. In particular, since the composition of the Fe-based initial alloy according to the present invention does not contain elements such as Nb, which function as a barrier to prevent growth of crystal size, the annealing conditions under ordinary conditions, for example, It is very difficult to control the particle size of the nanocrystalline to be 25 nm or less, and mass production may be difficult.

Specifically, the heat treatment may be performed at a heat treatment temperature of 200 to 410 ° C, more preferably, a heat treatment temperature of 280 to 410 ° C for 40 to 100 seconds. The heat treatment temperature may vary depending on the composition, , Nanocrystalline grains may not be generated or may be generated in a small amount. In this case, a Fe-based soft magnetic alloy having a low magnetic property may be produced. If the annealing temperature is higher than 410 ° C, the grain size of crystals produced in the alloy can be increased, and the grain size distribution of the resulting crystals becomes very wide to decrease the grain size uniformity. In addition to? -Fe, Fe And other intermetallic compound crystals are excessively produced, so that it is impossible to obtain an Fe-based alloy which is a homogeneous nanocrystalline of? -Fe.

According to an embodiment of the present invention, the rate of temperature rise up to the heat treatment temperature also greatly influences the grain size control of the produced nanocrystalline grains. For example, the rate of temperature increase from room temperature to the heat treatment temperature is 90 ° C / min or less And preferably from 28 to 80 DEG C / min or less. It is generally known that the rate of temperature increase in a heat treatment process for transforming from an amorphous alloy to a crystalline alloy is advantageous for obtaining a crystal having a small and uniform particle size at a high temperature elevation, for example, 100 ° C / min or more. It may be advantageous to uniformly produce the grain size of the produced crystal close to the average grain size by annealing at a desired annealing temperature after slowly raising the temperature at a heating rate of 90 ° C / min or less, unlike the conventional tendency . If the heating rate up to the temperature during the heat treatment exceeds 90 ° C / min, the particle size distribution of crystals produced may not be controlled to a desired level. However, when the heating rate is too low, the time required for the heat treatment process is prolonged, and crystals may be coarsened as the time for crystal formation and growth is prolonged.

The Fe-based soft magnetic alloy according to the present invention can be used for the production of uniform nano-grains such as Si elements in the composition. However, It does not contain the element which helps or Nb element which acts as a barrier of crystal growth, so that the grain size control may not be very easy. Accordingly, it is preferable to raise the temperature to 90 ° C / min or less as compared with the high-temperature elevation. By controlling the crystal size of the α-Fe and the production of the interfacial Fe-C compound in the proper amount, Fe is advantageous for manufacturing. In addition, as the temperature is raised at a low temperature, it can be more suitable for mass production, and the manufacturing cost is advantageously reduced.

In the second step, the heat treatment at the heat treatment temperature may be performed for 40 to 100 seconds. The heat treatment time may be varied depending on the heat treatment temperature to be performed. However, if the heat treatment is performed for less than 40 seconds, the transformation into the crystalline state may not be achieved to the desired level. If the heat treatment is performed for more than 100 seconds, There is a problem that the particle size of the particles is coarsened.

Meanwhile, the second step may be performed by adding a pressure and / or a magnetic field in addition to the heat. Through such additional processing, a crystal having magnetic anisotropy in a specific direction can be generated. The degree of the applied pressure or magnetic field may vary depending on the degree of desired physical properties, so that the present invention is not particularly limited thereto and may be carried out by employing known conditions.

The Fe-based soft magnetic alloy produced by the above-described production method may have a crystallized area value of 45 to 90%, more preferably 53 to 83%, according to the following relational expression (1).

[Relation 1]

Here, the area refers to the integral value of the crystalline region or amorphous region measured by X-ray diffraction (XRD) analysis at 0 to 90 ° angle (2?) With respect to the Fe-based soft magnetic alloy.

Since the crystallized area value satisfies 45 to 90%, crystals of? -Fe and Fe and other intermetallic compounds such as an Fe-C based compound are produced at an appropriate ratio, Can be advantageous. If the crystallized area value is less than 45%, the saturation magnetic flux density is low, which may make it difficult to exhibit excellent magnetic properties, and there is a fear that the magnetic properties may be changed during manufacture of the magnetic parts using the alloy. If the crystallized area value exceeds 90%, the formation of compound crystals between other metals such as Fe-C type compounds increases greatly, so that the saturation magnetic flux density decreases and the magnetic loss such as coercive force increases, May not be able to manifest the physical properties of the polymer.

The Fe-based soft magnetic alloy produced according to an embodiment of the present invention may have a saturation magnetic flux density of 1.5 T or more in the initial alloy state, and may be 1.71 T or more after appropriately heat-treated, and a coercive force of 500 A / m or less More preferably not more than 250 A / m, still more preferably not more than 185 A / m, so that the magnetic loss is small and it is suitable for downsizing the component.

The present invention will now be described more specifically with reference to the following examples. However, the following examples should not be construed as limiting the scope of the present invention, and should be construed to facilitate understanding of the present invention.

≪ Example 1 >

Empirical formula Fe _{85 . 3} B ₁₃ C ₁ Cu _{0 .7} were prepared. Fe alloy, Fe, B, C and Cu were weighed and prepared by arc melting method. The resulting Fe-base alloy was melted and then rapidly cooled at a rate of 10 ⁶ K / sec through melt spinning at a rate of 60 m / s in an Ar atmosphere to form a ribbon-shaped Fe-based alloy having a thickness of about 20 μm and a width of about 2 mm Magnetic initial alloys were prepared.

The Fe-based soft magnetic initial alloy thus prepared was heat-treated at a temperature elevation rate of 80 ° C / min at room temperature and maintained at 350 ° C for 1 minute to prepare an Fe-based soft magnetic alloy as shown in Table 1 below.

≪ Examples 2 to 52 >

The composition and / or the heat treatment conditions of the empirical formula were changed as shown in Tables 1 to 5 below to obtain Fe-based soft magnetic starting alloys and Fe-based soft magnetic alloys as shown in Tables 1 to 5 below. Alloy.

≪ Comparative Examples 1 to 9 &

The Fe-based soft magnetic initial alloy and the Fe-based soft magnetic alloy as shown in Table 6 below were prepared by changing the composition and / or the heat treatment conditions of the empirical formula as shown in Table 6 below.

<Experimental Example 1>

The following formulas (1) and (2) or (3) and (4) were calculated according to the content of Fe with respect to the composition of the initial alloy and the post-heat treated alloy prepared in Examples 1 to 52, To 5.

(1) In the empirical formula, when a is from 82 to 86 atomic%, Equations 1 and 2

[Equation 1]

&Quot; (2) &quot;

(2) In the empirical formula, when a is less than 78.5 to 82.0 at%, equations (3) and

&Quot; (3) &quot;

&Quot; (4) &quot;

<Experimental Example 2>

The following properties were evaluated for the initial alloys and the heat-treated alloys prepared in Examples 1 to 52 and Comparative Examples 1 to 9, respectively, and are shown in Tables 1 to 6 below.

1. Crystal structure analysis

The XRD pattern and TEM were analyzed to determine the average grain size and the crystallization area value of the crystalline phase and the generated crystal for the initial alloy and the alloy after the heat treatment.

Among the analyzed results, the XRD pattern of the initial alloy for Examples 1 to 5 is shown in Fig. 1, the XRD pattern of the initial alloy for Examples 6 to 10 is shown in Fig. 2, the XRD pattern of the initial alloy for Comparative Examples 1 to 5 Respectively. 4A and 4B show the XRD pattern of the Fe-based soft magnetic alloy heat-treated in Example 1, and FIGS. 5A and 5B show the XRD patterns of the Fe-based soft magnetic alloy heat-treated in Example 2, 6A and 6B show the XRD patterns of the Fe-based soft magnetic alloy heat-treated in Example 5, and FIGS. 7A and 7B show the XRD patterns of the Fe-based soft magnetic alloy heat-treated in Example 38, FIGS. 8A and 8B show XRD patterns of Fe-based soft magnetic alloys heat-treated at 42, and XRD patterns of Fe-based soft magnetic alloys heat-treated in Example 51 are shown in FIGS. 9A and 9B.

At this time, the crystallized area value was calculated by the following relational expression 1.

[Relation 1]

The average particle diameter was derived from the Scherrer formula as shown in the following equation (2).

[Relation 2]

Where D is the average grain diameter of the crystal,? Is the half width of the peak having the maximum intensity, and? Is the angle having the peak of the maximum intensity.

As can be seen from FIGS. 1 to 3, it can be confirmed that the amorphous initial alloys are implemented in Examples 1 to 10, but it can be confirmed that the crystalline initial alloys are produced in Comparative Examples 1 to 5.

It can also be seen from FIG. 4B to FIG. 9B that the average grain size of the resulting crystals calculated from the above-mentioned relational expression 2 with respect to the XRD pattern of the Fe-based soft magnetic alloy after the heat treatment is 16.5 nm to 19 nm. It can be confirmed that the calculated crystallized area value is 60.1 to 86.3%.

2. Evaluation of magnetic property

The coercivity and saturation magnetization values were calculated at 800k A / m through a vibrating sample magnetometer (VSM). VSM graphs of the initial alloys of Examples 1 to 5 are shown in Figs. 10A to 10E, respectively, and VSM graphs of Fe-based soft magnetic alloys after heat treatment of Examples 1 to 5 are shown in Figs. 11A to 11E, respectively Respectively. In addition, the VSM graphs for Examples 35, 38 and 41 prepared at different heat treatment times at a heat treatment temperature of 375 占 폚 are shown in Fig. The VSM graphs for Examples 38, 42 and 43, which were prepared with different heat treatment temperatures, are shown in Figs. 13a to 13b, and Examples 49, 50 and Examples The VSM graph for 51 is shown in Figs. 14A-14B.

The VSM results of the initial alloys shown in Figs. 10A to 10E show that the initial alloy before the heat treatment has a saturation magnetic flux density of 1.6 T (Fig. 10A) to 1.65 (Fig. 10C to Fig. 10E) and a coercive force of 83.34 A / m or less It can be confirmed that an alloy exhibiting magnetic properties is realized.

11A to 11E, the results of the VSM of the heat-treated alloy show that the saturation magnetic flux density is 1.80 T (FIG. 11C) to 1.93 T (FIG. 11B) through the heat treatment and the coercive force is 163.37 A / It is possible to confirm that an alloy exhibiting improved magnetic properties is realized.

As can be seen from FIG. 12, Example 38, which was heat-treated for 60 seconds compared to Example 35 (10 seconds) with a shorter heat treatment time and excessively longer Example 41 (180 seconds), has a higher saturation magnetic flux density and / Or have a low coercive force.

As can be seen from FIGS. 14A to 14C, the Fe-based soft magnetic alloy having a high saturation magnetic flux density and a low coercive force at a heating rate of 30 ° C / m, 55 ° C / m and 80 ° C / Can be confirmed.

3. Observation of crystal grain size

TEM photographs of the alloys heat-treated in Example 1 are shown in Figs. 15A and 15B.

Observation revealed that nanocrystalline grains were produced and the grain size of the grains was uniform.

Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Example 7 Example 8 Example 9 Example 10 Initial alloy Empirical formula
Fe _a B _b C _c Cu _d a (at%) 85.3 85.3 85.3 85.3 85.3 79.3 79.3 79.3 79.3 79.3 b (at%) 13 12 11 10 9 14 12 10 8 6.67 c (at%) One 2 3 4 5 6 8 10 12 13.33 d (at%) 0.7 0.7 0.7 0.7 0.7 0.7 0.7 0.7 0.7 0.7 b + c
(at%) 14 14 14 14 14 20 20 20 20 20 Equation 1 13 4.24 2.12 1.25 0.80 - - - - - Equation 2 3.32 3.32 3.32 3.32 3.32 - - - - - Equation 3 - - - - - 4.76 2.65 1.85 0.96 0.68 Equation 4 - - - - - 10.64 10.64 10.64 10.64 10.64 Crystalline phase Amorphous Amorphous Amorphous Amorphous Amorphous Amorphous Amorphous Amorphous Amorphous Amorphous Bs (T) 1.60 1.61 1.65 1.65 1.65 1.65 1.61 1.58 1.64 1.58 Hc (A / m) 43.89 38.04 78.05 55.38 83.34 44.28 37.74 52.74 104.53 64.07 Heat treatment temperature (° C) / Heat treatment time (sec) / Heating rate (° C / m) 350/60 /
80 350/60 /
80 350/60 /
80 350/60 /
80 350/60 /
80 360/60 /
80 360/60 /
80 360/60 /
80 360/60 /
80 360/60 /
80 Alloy after heat treatment Crystalline phase Crystal + amorphous Crystal + amorphous Crystal + amorphous Crystal + amorphous Crystal + amorphous Crystal + amorphous Crystal + amorphous Crystal + amorphous Crystal + amorphous Crystal + amorphous Crystal average particle diameter (nm) 17 16.6 17.2 17.6 16.5 15.2 15.4 17.0 16.3 15.9 Crystallization area value (%) 65.3 72.8 71.8 72.3 72.6 52.8 53.7 52.4 53.1 54.8 Bs (T) 1.89 1.93 1.80 1.88 1.88 1.69 1.67 1.66 1.68 1.68 Hc (A / m) 65.49 67.07 157.42 142.70 163.37 68.46 59.20 166.94 53.14 59.13

Example 11 Example 12 Example 13 Example 14 Example 15 Example 16 Example 17 Example 18 Example 19 Example 20 Initial alloy Empirical formula
Fe _a B _b C _c Cu _d a (at%) 85.1 85.6 82.5 84.5 85.8 83.3 82.3 82.51 82.01 82.2 b (at%) 7.1 6.6 9 8 8 10 16.0 16 16 16.6 c (at%) 7.1 7.1 8 7 5.5 6 1.0 0.99 0.99 0.7 d (at%) 0.7 0.7 0.5 0.5 0.7 0.7 1.0 0.5 1.0 0.5 b + c
(at%) 14.2 13.7 17 15 13.5 16 17 16.99 16.99 17.3 Equation 1 0.375 0.349 0.397 0.431 0.62 0.68 16.0 16.24 16.24 28.34 Equation 2 3.32 3.33 3.58 3.61 3.32 3.30 3.29 3.58 3.00 3.58 Equation 3 - - - - - - Equation 4 - - - - - - Crystalline phase Crystal + amorphous Crystal + amorphous Amorphous Amorphous Amorphous Amorphous Amorphous Amorphous Amorphous Amorphous Bs (T) 1.78 1.83 1.62 1.64 1.65 1.63 1.62 1.62 1.61 1.62 Hc (A / m) 321.4 297.6 68.42 59.38 62.74 54.31 52.67 68.91 55.74 57.87 Heat treatment temperature (캜) /
Heat treatment time (sec) /
Heating rate (° C / m) 350 /
60 /
80 350/60 /
80 350/60 /
80 350/60 /
80 350/60 /
80 350/60 /
80 350/60 /
80 350/60 /
80 350/60 /
80 350/60 /
80 Alloy after heat treatment Crystalline phase Crystal + amorphous Crystal + amorphous Crystal + amorphous Crystal + amorphous Crystal + amorphous Crystal + amorphous Crystal + amorphous Crystal + amorphous Crystal + amorphous Crystal + amorphous Crystal average particle diameter (nm) 54.7 61.9 17.9 17.5 16.6 15.2 16.5 17.0 18.9 25.9 Crystallization area value (%) 93.1 92.4 72.4 70.8 79.4 69.4 75.4 74.9 72.6 83.1 Bs (T) 1.89 1.96 1.75 1.81 1.94 1.79 1.73 1.71 1.70 1.71 Hc (A / m) 1953.4 2017.90 80.41 73.14 78.41 50.68 46.48 56.47 65.47 67.48

Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Comparative Example 5 Comparative Example 6 Comparative Example 7 Comparative Example 8 Comparative Example 9 Initial alloy Empirical formula
Fe _a B _b C _c Cu _d a (at%) 86.3 86.3 86.0 87.3 86.2 78.2 85.6 84.4 78.5 b (at%) 11.0 12.0 10.0 11 8.7 15.0 9.0 9 18.9 c (at%) 2.0 1.0 3.0 1.0 4.6 6.3 5.0 15 One d (at%) 0.7 0.7 1.0 0.7 0.5 0.5 0.4 1.6 1.6 b + c
(at%) 13 13 13 12 13.3 21.3 14 16.6 19.9 Crystalline phase Crystalline Crystalline Crystalline Crystalline Crystalline Amorphous Amorphous Crystal + amorphous Crystal + amorphous Bs (T) 1.87 1.85 1.83 1.91 1.83 1.57 1.67 1.70 1.58 Hc (A / m) 541.64 592.16 618.48 528.64 604.84 52.41 62.18 242.64 217.84 Heat treatment temperature (° C) / Heat treatment time (sec) / Heating rate (° C / m) 350 /
60 /
80 350 /
60 /
80 350 /
60 /
80 350 /
60 /
80 350 /
60 /
80 350 /
60 /
80 350 /
60 /
80 350 /
60 /
80 350 /
60 /
80 Alloy after heat treatment Crystalline phase Crystalline Crystalline Crystalline Crystalline Crystalline Crystalline + amorphous Crystalline + amorphous Crystalline Crystalline Crystal average particle diameter (nm) 50.49 50.82 51.21 49.76 53.69 20.64 21.39 30.4 30.6 Bs (T) 1.91 1.94 1.93 1.95 1.89 1.64 1.86 1.80 1.72 Hc (A / m) 2234.12 2164.85 2264.34 1986.42 2354.56 124.18 196.5 1246.34 1126.76

Example
31 Example
32 Example
33 Example
34 Example
35 Example
36 Example
37 Example
38 Example
39 Example
40 Example
41 Initial alloy Empirical formula
Fe _a B _b C _c Cu _d a (at%) 81.9 78.5 78.5 81.9 85.3 85.3 85.3 85.3 85.3 85.3 85.3 b (at%) 8 7.4 19.4 16 13 13 13 13 13 13 13 c (at%) 8.9 13 One 1.6 One One One One One One One d (at%) 1.2 1.1 1.1 0.5 0.7 0.7 0.7 0.7 0.7 0.7 0.7 b + c
(at%) 20.4 20.4 20.4 17.6 14 14 14 14 14 14 14 Equation 1 - - - - 13 13 13 13 13 13 13 Equation 2 - - - - 3.32 3.32 3.32 3.32 3.32 3.32 3.32 Equation 3 1.51 0.79 97 39.5 - - - - - - - Equation 4 8.26 8.45 8.45 12.79 - - - - - - - Crystalline phase Crystal + amorphous Amorphous Amorphous Amorphous Amorphous Amorphous Amorphous Amorphous Amorphous Amorphous Amorphous Bs (T) 1.81 1.62 1.64 1.66 1.60 1.60 1.60 1.60 1.60 1.60 1.60 Hc (A / m) 241.32 38.9 48.5 51.6 43.89 43.89 43.89 43.89 43.89 43.89 43.89 Heat treatment temperature (캜) /
Heat treatment time (sec) /
Heating rate (° C / m) 350/60 /
80 350/60 /
80 350/60 /
80 350/60 /
80 375/10 /
80 375/35 /
80 375/45 /
80 375/60 /
80 375/95 /
80 375 /
110/80 375 /
180/80 Alloy after heat treatment Crystalline phase Crystal + amorphous Crystal + amorphous Crystal + amorphous Crystal + amorphous Crystal + amorphous Crystal + amorphous Crystal + amorphous Crystal + amorphous Crystal + amorphous Crystal + amorphous Crystal + amorphous Crystal average particle diameter (nm) 40.8 17.7 17.4 16.8 18 18 19 19 20 22 20 Crystallized area value (%) 89.8 72.9 68.4 65.8 65.4 73.8 76.5 80.0 82.4 85.6 85.9 Bs (T) 1.84 1.68 1.69 1.73 1.79 1.80 1.87 1.91 1.91 1.91 1.88 Hc (A / m) 1683.42 102.6 94.62 73.8 132 138 141 140 145 160 159

Example
42 Example
43 Example
44 Example
45 Example
46 Example
47 Example
48 Example
49 Example
50 Example
51 Example
52 Initial alloy Empirical formula
Fe _a B _b C _c Cu _d a (at%) 85.3 85.3 85.3 85.3 85.3 85.3 85.3 85.3 85.3 85.3 85.3 b (at%) 13 13 13 13 13 13 13 13 13 13 13 c (at%) One One One One One One One One One One One d (at%) 0.7 0.7 0.7 0.7 0.7 0.7 0.7 0.7 0.7 0.7 0.7 b + c
(at%) 14 14 14 14 14 14 14 14 14 14 14 Equation 1 13 13 13 13 13 13 13 13 13 13 13 Equation 2 3.32 3.32 3.32 3.32 3.32 3.32 3.32 3.32 3.32 3.32 3.32 Equation 3 - - - - - - - - - - - Equation 4 - - - - - - - - - - - Crystalline phase Amorphous Amorphous Amorphous Amorphous Amorphous Amorphous Amorphous Amorphous Amorphous Amorphous Amorphous Bs (T) 1.60 1.60 1.60 1.60 1.60 1.60 1.60 1.60 1.60 1.60 1.60 Hc (A / m) 43.89 43.89 43.89 43.89 43.89 43.89 43.89 43.89 43.89 43.89 43.89 Heat treatment temperature (캜) /
Heat treatment time (sec) /
Heating rate (° C / m) 400/60 /
80 420/60 /
80 190/60 /
80 210/60 /
80 270/60 /
80 285/60 /
80 325/60 /
25 325/60 /
30 325/60 /
55 325/60 /
80 325/60 /
95 Alloy after heat treatment Crystalline phase Crystal + amorphous Crystal + amorphous Crystal + amorphous Crystal + amorphous Crystal + amorphous Crystal + amorphous Crystal + amorphous Crystal + amorphous Crystal + amorphous Crystal + amorphous Crystal + amorphous Crystal average particle diameter (nm) 22 29 - - 16 19 24 21 20 17 17 Crystallized area value (%) 82.8 86.8 - - 59.3 62.4 48.7 53.4 63.0 60.1 58.2 Bs (T) 1.91 1.94 1.63 1.72 1.75 1.83 1.88 1.89 1.914 1.90 1.91 Hc (A / m) 167 179 89 91 132 147 180 157 143 140 151

Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Comparative Example 5 Comparative Example 6 Comparative Example 7 Comparative Example 8 Comparative Example 9 Initial alloy Empirical formula
Fe _a B _b C _c Cu _d a (at%) 86.3 86.3 86.0 87.3 86.2 78.2 85.6 84.4 78.5 b (at%) 11.0 12.0 10.0 11 8.7 15.0 9.0 9 18.9 c (at%) 2.0 1.0 3.0 1.0 4.6 6.3 5.0 15 One d (at%) 0.7 0.7 1.0 0.7 0.5 0.5 0.4 1.6 1.6 b + c
(at%) 13 13 13 12 13.3 21.3 14 16.6 19.9 Crystalline phase Crystalline Crystalline Crystalline Crystalline Crystalline Amorphous Amorphous Crystal + amorphous Crystal + amorphous Bs (T) 1.87 1.85 1.83 1.91 1.83 1.57 1.67 1.70 1.58 Hc (A / m) 541.64 592.16 618.48 528.64 604.84 52.41 62.18 242.64 217.84 Heat treatment temperature (° C) / Heat treatment time (sec) / Heating rate (° C / m) 350 /
60 /
80 350 /
60 /
80 350 /
60 /
80 350 /
60 /
80 350 /
60 /
80 350 /
60 /
80 350 /
60 /
80 350 /
60 /
80 350 /
60 /
80 Alloy after heat treatment Crystalline phase Crystalline Crystalline Crystalline Crystalline Crystalline Crystalline + amorphous Crystalline + amorphous Crystalline Crystalline Crystal average particle diameter (nm) 50.49 50.82 51.21 49.76 53.69 20.64 21.39 30.4 30.6 Bs (T) 1.91 1.94 1.93 1.95 1.89 1.64 1.86 1.80 1.72 Hc (A / m) 2234.12 2164.85 2264.34 1986.42 2354.56 124.18 196.5 1246.34 1126.76

It can be seen from Tables 1 to 5 that the Fe-based soft magnetic alloy according to the embodiments exhibits a higher magnetic flux density and / or a lower coercive force than the Fe-based soft magnetic alloy according to the comparative example, have.

In Examples 11 to 24 in which the value of a was in the range of 82 to 86 at% in the empirical formula, crystals were formed in the initial alloy due to the value of Equation 1 being less than 0.38 in Examples 11 and 12, As a result, it can be seen that the coercive force is increased as compared with Examples 13 to 20, which satisfy Equation (1), and it can be seen that the coercive force is remarkably increased especially after the heat treatment. In addition, it can be confirmed that the grain size of the crystals produced is more than 30 nm and becomes coarse. In the case of Example 21 in which the value of Equation 1 exceeds 28.5, an amorphous alloy was realized in the initial alloy, but it can be confirmed that the coercive force after the heat treatment is remarkably increased. This is because the crystal phase is nanocrystalline and the average grain size of the crystal is 28.4 nm. However, the coercive force is expected to be increased about 4 times as compared with Example 20 as the coarse grain size is included. When the content of B in the alloy is excessive, It can be seen that the control is not easy.

In the case of Example 22 in which the value of Equation 2 is less than 2.92, it can be expected that the coercive force is large and the magnetic loss increases in comparison with Example 23. [

In Examples 25 to 34 in which the value of a is less than 78.5 to 82.0 at% in the empirical formula, it can be seen that the coercive force of Example 25 having a value of less than 0.67 is larger than that of Example 26 .

In the case of Example 31 in which the value of the formula (4) was less than 8.3, crystals were generated in the initial alloy as compared with Examples 32 to 34, and it was confirmed that the coercive force was remarkably large after the heat treatment.

In addition, in the case of Example 35 and Example 36 in which the heat treatment time was shorter than 40 seconds in Examples 35 to 41, which were manufactured by varying the heat treatment time at the heat treatment temperature of 375 占 폚, It can be confirmed that the coercive force is increased compared to Example 39 in the case of Example 40 and Example 41 which were heat-treated for more than 100 seconds.

Example 44 having a heat treatment temperature of less than 200 占 폚 in Example 38 and Examples 42 to 47, which were prepared with different heat treatment temperatures during the heat treatment, had Fe-based soft magnetic alloys having a lower saturation magnetic flux density than Example 45 You can see that it is implemented. It can also be seen that the coercive force was increased in Example 43 in which the heat treatment temperature exceeded 410 캜, as compared with Example 42.

Further, it can be confirmed that the coercive force of Example 48 in which the rate of temperature increase is 25 ° C / m in Examples 48 to 52, which was manufactured by varying the heating rate at the time of heat treatment, is higher than that in Example 49. In addition, the coercive force of Example 52 having a composting rate of 95 캜 / m was increased as compared with Example 51, which was similar to that of Example 51 with an average crystal grain size of 17 nm, And it is expected that Example 51 will have a more uniform crystal grain size distribution.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.

Claims (14)

Empirical formula Fe _a B _{b C c} and _d expressed as Cu, in the empirical formula a, b, c and d is at% (atomic percent) of the element, 78.5≤a≤86, 13.5≤b + c≤21, 0.5 Lt; / = d &lt; / = 1.5; And
And then heat-treating the Fe-based initial alloy. The method according to claim 1,
In the empirical formula, a is 82 to 86 at%, b and c are a total of 13.5 to 17.5 at%, and a value according to the following formula 1 is 0.38 to 28.5.
[Equation 1]

3. The method of claim 2,
In the empirical formula, a and d are values in accordance with the following formula (2): 2.92 to 3.70.
&Quot; (2) &quot;

3. The method of claim 2,
Wherein the value according to Equation (1) is 0.65 to 16.1. 3. The method of claim 2,
In the empirical formula, c is 1.0 to 4.0 at%. The method according to claim 1,
In the empirical formula, a is less than 77.5 to 82.0 at%, b and c are in a total of more than 16.5 at% to 21 at%, and a value of the following equation (3) is 0.67 or more.
&Quot; (3) &quot;

The method of claim 6, wherein
In the empirical formula, a and d are values of the following formula (4): 8.3 to 12.8.
&Quot; (4) &quot;

The method according to claim 6,
Wherein the value of the formula (3) is 0.85 to 200. The method according to claim 1,
Wherein the Fe-based initial alloy is amorphous and the Fe-based soft magnetic alloy has a heteroatom array structure including both an amorphous region and a crystalline region. 10. The method of claim 9,
Wherein the amorphous and crystalline regions have a volume ratio of 5.5: 4.5 to 1: 9. The method according to claim 1,
Wherein the heat treatment is performed at a heat treatment temperature of 200 to 410 캜 for 40 to 100 seconds. 12. The method of claim 11,
Wherein the Fe-based soft magnetic alloy is heat-treated at a heating rate of 90 DEG C / min or less up to the predetermined heat treatment temperature.
More preferably 28 to 82 DEG C / min The method according to claim 1,
The prepared Fe-based soft magnetic alloy has a crystallized area value of 45 to 90% according to the following relational expression 1:
[Relation 1]

Here, the area refers to the integral value of the crystalline region or the amorphous region measured by X-ray diffraction (XRD) analysis at 0 to 90 ° angle (2?) With respect to the Fe-based soft magnetic alloy. 14. The method of claim 13,
Wherein the Fe-based soft magnetic alloy has the crystallized area value of 53 to 83%.

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