WO2018043963A1 - Fe-based soft magnetic alloy and magnetic part using same - Google Patents

Abstract

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 empirical formula Fe_aB_bC_cCu_d wherein a, b, c and d indicate the at%(atomic percent) of corresponding elements, 78.5≤≤a≤≤87.0, 12≤b+c≤≤21 and 0.5≤≤d≤≤1.5, and comprises α-Fe and metal compounds formed with Fe and at least one element of B, C and Cu. Accordingly, the alloy has a high saturated magnetic flux density, excellent high-frequency characteristics and low coercivity, and thus can be very easily employed as a compact and light high-performance and high-efficiency part. Also, the present invention incurs a very low production cost and can be mass-produced by facilitating alloy production by allowing easy control of components, contained in the alloy, during the alloy production process. Accordingly, the present invention can be widely applied as a magnetic part of electric and electronic devices such as a high-power laser, a high-frequency power supply, a high-speed pulse generator, an SMPS, a high-pass filter, a low-loss high-frequency transformer, a high-speed switch and wireless charging.

Description

FE-based soft magnetic alloy and magnetic parts through it

The present invention relates to a Fe-based soft magnetic alloy, more specifically, a high saturation magnetic flux density is suitable for implementation in small and light weight parts, low magnetic loss Fe-based soft magnetic properties that can express excellent magnetic performance It relates to an alloy and magnetic parts through it.

Soft magnetic materials are materials for magnetic cores such as various transformers, choke coils, various sensors, saturable reactors, magnetic switches, etc., and various electric and electronic devices for supplying power and converting power such as transformers, laser power supplies and accelerators for distribution. It is widely used in. The technical demand for such electric and electronic devices is small, light weight, high performance / high efficiency, and low product cost. In order to satisfy such technical demands, the physical properties of the magnetic core material for magnetic cores are high saturation magnetic flux density and low magnetic loss. Specifically, the output of the magnetic core can be calculated as the formula voltage (E) = magnetic flux density (B _m ) × 4.44 frequency (f) × winding (N) × magnetic core cross-sectional area (S), in order to increase the voltage (E) Each factor must be high. The magnetic flux density (Bm) and the frequency (f) are dependent on the magnetic material of the magnetic core among the above factors. In order to increase the magnetic flux density, a material having a high saturation magnetic flux density of the magnetic material and a low magnetic loss is required. The magnetic loss is calculated as the sum of hysteresis loss, eddy current loss, and abnormal loss. The eddy current loss and abnormal loss depend on the magnetic domain size, specific resistance, and magnetic core thickness of the magnetic material of the magnetic core. The higher the thinner magnetic core, the better the magnetic loss. In addition, in order to increase the frequency, the high frequency loss of the magnetic material should be small, but increasing the frequency (f) is limited to the material approach as a circuit approach is required.

On the other hand, amorphous alloys containing Fe, which are known as materials that have high saturation magnetic flux density and low loss at the same time as commercially available magnetic materials, do not have crystal grains, and thus do not have crystal magnetic anisotropy and have low magnetic hysteresis. As the hysteresis loss is small and shows excellent soft magnetic property, the amorphous alloy containing Fe is attracting attention as an energy saving material.

The amorphous alloy containing Fe is an element forming an alloy, and other metals, such as Si, B, and P, which increase amorphous forming ability, or metalloids such as Cu, Nb, and Zr elements serving as nucleation sites and / or diffusion barriers. (metalloid) is being developed and manufactured. However, there is a problem that the saturation magnetic flux density of the alloy is lowered when the content of the metalloid is increased as described above, and when the metal content is reduced, it is not formed amorphous or a post-treatment process for changing properties (Ex. Heat treatment). The crystal size increases significantly, increasing coercive force and magnetic loss. In addition, the inclusion of a metalloid element may cause other problems. Specifically, Fe-based amorphous alloys containing P, which are known to improve amorphous forming ability, are easily volatilized in a subsequent process for changing properties, thereby making them difficult to handle. While it is very difficult to proceed with the post-process, the productivity of the alloy in the post-process is significantly lowered, and may be very disadvantageous for mass production. In addition, when B is known to have an amorphous forming ability, the gap between the primary crystallization temperature and the secondary crystallization temperature of the prepared alloy becomes very narrow, and in addition to α-Fe, post-treatment compounds (ex.Fe- There is a problem that B) can be produced to make it difficult to obtain homogeneous crystals of α-Fe. In addition, when a rare metal such as Nb is included, it is advantageous to control grain size in a later process, but there is a problem in that the production cost increases significantly as the unit cost of the element is high.

Therefore, while making the Fe-based alloy amorphous, high saturation magnetic flux density, low coercive force, and low magnetic loss are expressed, and further, the size of crystals formed after post-process (Ex. Heat treatment) for the change of magnetic properties is made small and uniform. In addition to Fe, which is easy to mass-produce and reduce production costs, it is urgent to develop alloys containing metalloids.

The present invention has been made in view of the above, and has a high saturation magnetic flux density, excellent high-frequency characteristics and low coercive force, and is a Fe-based soft magnetic alloy that is very easy to be deployed as a high performance / high efficiency small / light weight component. It aims to provide.

In addition, the present invention provides a Fe-based soft magnetic alloy capable of expressing a high level of magnetic properties by producing crystals having a uniform but small particle diameter through a post-process despite the absence of high cost components such as rare earth elements. There is another purpose to things.

Furthermore, the present invention provides an Fe-based soft magnetic alloy in which the magnetic properties of the alloy are easily controlled in the manufacturing process, and thus the magnetic properties expressed are equal or higher than those of the conventional ones. There is another purpose.

In addition, another object of the present invention is to provide a magnetic component of various electric and electronic devices including the Fe-based soft magnetic alloy according to the present invention which can perform energy supply and conversion functions excellently.

In order to solve the above problems, the present invention is represented by the empirical formula Fe _a B _b C _c Cu _d , Fe-containing Fe and a metal compound formed between at least one element of Fe and B, C and Cu Provides a soft magnetic alloy. However, in the empirical formula, a, b, c and d are at% (atomic percent) of the corresponding elements, and 78.5≤a≤87.0, 12≤b + c≤21, and 0.5≤d≤1.5.

According to an embodiment of the present invention, the metal compound may include a Fe-B compound and a Fe-C compound. In addition, the Fe-C compound may include any one or more compounds of Fe ₃ C, Fe ₉₃ C ₇ and C ₄ Fe _{0 .63.}

In addition, the Fe-based soft magnetic alloy may be 70% or less of the crystallized area value according to Equation 1 below, more preferably 30 to 70%, even more preferably 40 to 70%.

[Equation 1]

In this case, the area refers to an integral value for the crystalline region or the amorphous region measured during X-ray diffraction (XRD) analysis at a 10 to 90 ° angle (2θ) for the Fe-based soft magnetic alloy.

The Fe-based soft magnetic alloy may have an average particle diameter of 18 to 30 nm and a maximum particle size of 50 nm or less.

In addition, b and c in the empirical formula may be 8≤b≤20 and 1≤c≤14, respectively.

In addition, the shape of the Fe-based soft magnetic alloy may be powder, ribbon or rod (rod) type.

In addition, the present invention provides a magnetic shielding member including a Fe-based soft magnetic alloy according to the present invention, the magnetic shielding member may be provided with a Fe-based soft magnetic alloy fragmented to reduce the generation of eddy current.

In addition, the magnetic shielding member may be provided on one surface of the antenna unit to be implemented as an antenna module.

In addition, the present invention provides a magnetic core comprising a Fe-based soft magnetic alloy according to the present invention, the magnetic core may be implemented as a coil component including a coil wound to the outside.

Hereinafter, the term used by this invention is demonstrated.

As used herein, the term "initial alloy" refers to an alloy that has not undergone a separate treatment, for example, heat treatment, for the purpose of changing the properties of the alloy produced.

According to the present invention, it has very high saturation magnetic flux density, excellent high frequency characteristics and low coercive force, so that it is very easy to develop into a small / light weight component of high performance / high efficiency. In addition, the present invention is very low production cost, the components contained in the alloy is easily controlled in the manufacturing process of the alloy is easy to manufacture the alloy mass production is possible according to the large output laser, high frequency power supply, high-speed pulse generator, SMPS, It can be widely applied as magnetic parts of electric and electronic devices such as high frequency filter, low loss high frequency transformer, high speed switch, wireless charging.

1 is a Fe-based soft magnetic alloy according to an embodiment of the present invention Fe _{85 . 3} B ₁₀ C ₄ Cu _{0 .7} by the property evaluation results of the drawings alloy, Figure 1a is a view showing the XRD pattern of the alloy, and Figure 1b is a TEM image, and FIG 1c is a view of the SAD pattern, Figure 1d is A diagram showing a hysteresis curve according to VSM.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art may easily implement the present invention. As those skilled in the art would realize, the described embodiments may be modified in various different ways, all without departing from the spirit or scope of the present invention.

Fe-based soft magnetic alloy according to the present invention is an alloy represented by the empirical formula Fe _a B _b C _c Cu _d , wherein a, b, c and d is at% (atomic percent) of the element, 78.5≤≤ It satisfies a≤≤87.0, 12≤≤b + c≤≤21, and 0.5≤d≤≤1.5.

First, the Fe is a main element of the alloy to express the magnetic, Fe is included in the alloy at 78.5 at% or more to improve the saturation magnetic flux density. If Fe is less than 78.5at%, it may not be possible to achieve a desired level of saturation magnetic flux density. In addition, when the ratio of Fe exceeds 87.0 at%, it may be difficult to form amorphous even in the case of liquid quenching for the preparation of amorphous initial alloy, and the crystals formed in the initial alloy may exhibit uniform crystal growth in the heat treatment process for the characteristic change. There is a problem in that magnetic losses increase, such as interference, and as the coercivity increases, as the size of the generated crystal becomes larger than a desired level.

Next, in the empirical formula, B and C are elements having an amorphous forming ability, through which the initial alloy may be formed into an amorphous phase. In addition, element C is combined with element B, which makes it easy to control the particle size of the α-Fe crystals produced to a desired level, compared to the case containing only element B, and improves the thermal stability of the initial alloy to be homogeneous during heat treatment. There is an advantage in obtaining one α-Fe crystal. If the sum of element B and element C is less than 12 at% in the alloy, it may be difficult to form amorphous even during liquid quenching for the preparation of amorphous initial alloy. In addition, the resulting crystals make it difficult to grow the initial alloy crystals to have a uniform particle size, and may include crystals having a coarse particle diameter, which may increase magnetic loss. There is this. In addition, when the total amount of C and B elements in the alloy is included in excess of 21 at%, the content of the Cu element to be described later for the production of the alloy of the nanocrystals should be increased, so the content of the Fe element may be further lowered. As a result, the desired saturation flux density may not be achieved. Further, in addition to α-Fe crystals, Fe easily forms compounds with B and / or C, and as the amount thereof increases, there is a problem that the saturation magnetic flux density may further decrease.

In addition, the content of the elements B and C contained in the alloy according to an embodiment of the present invention is the relationship 1,

Can be satisfied. By satisfying the relation 1, the initial alloy can be prepared in an amorphous phase, and at the same time, the thermal stability of the alloy can be further improved to obtain a homogeneous crystal of α-Fe. If the value of c / (b + c) is less than 0.047, the thermal stability of the alloy is lowered, and the formation of Fe-B and / or Fe-C compounds in addition to the crystallization of α-Fe may significantly increase during heat treatment. There may be a lot of difficulties in the control of the heat treatment process, there is a problem that the saturation magnetic flux density of the initial alloy or the heat treatment alloy may be reduced or the magnetic loss may be increased, and the particle size control of the α-Fe crystal is difficult to have a uniform particle size It may not be possible to produce a magnetic material having α-Fe crystals. In addition, if the value of c / (b + c) exceeds 0.66, nanocrystal grains may be formed in the initial alloy, so that it is very difficult to control the grain size of the crystals produced during the heat treatment, and to produce crystals having coarse grain sizes. Can be.

Element B contained in the alloy according to an embodiment of the present invention may be included in the alloy 8 ~ 20at%. If element B is included in excess of 20 at%, the spacing between crystallization temperatures of the prepared initial alloy is narrowed, thereby reducing passion stability, and thus, it may be difficult to obtain homogeneous α-Fe crystals. In addition, when the element B is contained in less than 8at% crystals may be formed in the initial alloy, the crystals are difficult to uniformly produce the particle size distribution of the crystals produced in the heat-treated alloy, it can grow into coarse crystals there is a problem.

In addition, the element C included in the alloy according to an embodiment of the present invention may be included in the alloy 1 ~ 14at%. If element C is included in the alloy less than 1 at%, it is difficult to produce the initial alloy in an amorphous phase. For this reason, if the above-mentioned element B is increased, it may cause a secondary problem that the thermal stability of the initial alloy is lowered. In addition, it is difficult to control the particle size of the α-Fe crystals produced during the heat treatment of the prepared initial alloy, and thus it may not be possible to manufacture a magnetic material having the α-Fe crystals having a uniform particle size. In addition, if element C contains more than 14 at% in the alloy, α-Fe crystals having a particle size of 30 nm or more may be formed in the initial alloy. There is a problem that makes particle size control difficult. In addition, as other intermetallic compounds are already produced in the initial alloy, the amount in the alloy of the α-Fe crystals generated during heat treatment may not be included at a desired level. In addition, the coercive force is significantly increased, and as the magnetic loss is large, the desired magnetic properties are not expressed, so it may be difficult to apply the miniaturized magnetic material.

Meanwhile, the Si element is not included in the composition of the Fe-based soft magnetic alloy according to the present invention. Conventional Fe-based soft magnetic alloys include Si elements, which improve the amorphous formability of the alloy and at the same time help to uniformize the particle diameter of the α-Fe crystals produced. However, when the Si is included in the alloy, there is a problem that the content of semimetals other than Fe, for example, B, C, Cu or the content of Fe should be reduced, and the content of Fe decreases in the high saturation magnetic flux density. This makes it difficult to implement Fe-based alloys. Accordingly, the Fe-based alloy of the present invention implements a high saturation density by increasing the content of Fe element instead of Si element, but as the Si element is not included, the crystallization of the crystal in the alloy is very difficult and uniform. There are also disadvantages in which an alloy having a particle size is not very easy to manufacture. In order to solve this disadvantage, the element C is a Fe element and the relationship 2 as described above,

In this way, Fe-C-based compounds can be produced at an appropriate level during the heat treatment of the initial alloy, so that despite the absence of Si elements, it is possible to achieve the desired level of grain size of the α-Fe crystals. . If a / c is less than 5.6 in Equation 2, the saturation magnetic flux density may decrease, it may be difficult to produce an amorphous initial alloy, and it may be difficult to control the particle size of the α-Fe crystal generated during heat treatment. In addition, when a / c is greater than 87.0 in Equation 2, it is difficult to form the α-Fe crystal, and coarse α-Fe crystals may be generated or α-Fe crystals having a very large particle size distribution may be generated. have.

Next, in the empirical formula, Cu is an element that serves as a nucleation site capable of generating α-Fe crystals in the initial alloy, and the amorphous initial alloy may be implemented as a nanocrystalline alloy. The Cu element is preferably included at 0.5 to 1.5 at% in the alloy for remarkable expression of the desired physical properties. If the Cu element is contained less than 0.5 at% in the alloy, the specific resistance of the alloy produced is greatly reduced and the loss due to eddy current can be increased, and nano-crystal grains of α-Fe are not produced to the desired level in the heat-treated alloy. You may not. In addition, if the Cu element is contained in the alloy exceeds 1.5 at%, the effect of the element can be reduced as the content of the above-described Fe, B, C element is relatively reduced, the grain size of the crystal produced during the heat treatment Control can be difficult.

In addition, in the empirical formula b, c and d is the relation 3,

Can be satisfied. By satisfying the above Equation 3, the initial alloy can be prepared in an amorphous phase, and at the same time, it is easy to manufacture a nanocrystalline alloy. If (b + c) / d in Equation 3 is less than 8, the amorphous forming ability of the initial alloy may be reduced or coarse crystals may be produced in the initial alloy. If it exceeds 42, it may be difficult to produce nanocrystals even through heat treatment.

The Fe-based soft magnetic alloy according to the embodiment of the present invention described above may be amorphous or crystalline, or may be a heteroatomic structure including both an amorphous region and a crystalline region. Preferably, the Fe-based soft magnetic alloy having an amorphous phase may have a structure in an initial alloy state which has not been heat treated, and in this case, the Fe-based soft magnetic alloy may have a powder shape.

Fe-based soft magnetic alloy having a crystalline phase may be a structure in the alloy after the initial alloy heat treatment, the crystalline phase may be nanocrystalline, the average particle diameter of the crystalline phase may be 30nm or less. In addition, the heteroatomic array structure may be a structure in the alloy after the initial alloy or heat treatment. In this case, when the heteroatom-array structure is initially alloyed, the crystalline compound may have a fine particle diameter of 10 nm or less, preferably 8 nm or less. In addition, when the hetero-atomic array structure is an alloy after heat treatment, the crystalline compound may have an average particle diameter of 30 nm or less, preferably 28 nm or less, thereby achieving desired physical properties.

On the other hand, even if the average grain size of the crystal grains satisfies the preferred range, in some cases there may be a variation in the coercive force. That is, in the case where the maximum particle size of the crystal exceeds 50 nm, there may be an increase in coercive force in case it does not. Accordingly, the maximum particle size of the crystal produced in the Fe-based soft magnetic alloy is preferably 50 nm or less.

When the Fe-based soft magnetic alloy according to an embodiment of the present invention has a heteroatomic structure, amorphous regions and crystalline regions may be included in the alloy in a volume ratio of 6: 4 to 3: 7. If the amorphous region and the crystalline region exceed the volume ratio of 6: 4 to increase the amount of the amorphous region, it may not be able to express desired magnetic properties such as a desired level of saturation magnetic flux density. In addition, if the amorphous region and the crystalline region have a larger crystalline region at a volume ratio of less than 3: 7, crystal formation of a compound other than α-Fe crystal among the resulting crystals may be increased, and the desired magnetic properties may be expressed. You may not be able to.

The above-described Fe-based soft magnetic alloy may be a powder, a strip, or a ribbon in a state before heat treatment, but is not limited thereto, and may be appropriately modified in consideration of the shape of the final magnetic material, the heat treatment process, and the like. In addition, the Fe-based soft magnetic alloy may have a ribbon or rod shape after heat treatment, and the cross section of the rod shape may be polygonal, circular, or elliptical, but is not limited thereto.

In addition, the Fe-based alloy according to the present invention includes a-Fe, and metal compounds formed between Fe and at least one element of B, C and Cu.

The Fe-based alloy includes metal compounds formed between at least one of Fe and B, C, and Cu in addition to α-Fe. The Fe-based alloy may be a Fe-based alloy whose grain size is controlled to a desired level through the metal compound. have. In other words, the compound between Fe and other metalloids produced in a certain amount in the alloy acts as a barrier to prevent coarsening of α-Fe beyond the desired particle diameter, and Fe-based containing α-Fe with a more uniform particle size distribution. It can be implemented in an alloy.

The α-Fe and the metal compounds are included in an appropriate ratio, the particle diameter of the α-Fe produced through this is uniformly controlled to the desired level, it is possible to suppress the generation of coarse α-Fe. In addition, there is an advantage that the homogeneity of the alloy implemented is improved.

The metal compounds formed between at least one of Fe and B, C, and Cu may include any one or more of Fe-B compounds and Fe-C compounds. However, the Fe-based alloy containing the Fe-B compound may be thermally inferior to the Fe-based alloy containing the Fe-C compound, and may be homogeneous as the content of the α-Fe in the resulting crystal may be low. There is a problem that one alloy cannot be manufactured and all the desired physical properties cannot be expressed. Accordingly, more preferably, the metal compound may include a Fe-C compound, and through this, thermal stability of the alloy may be improved, thereby making it possible to easily prepare an alloy having a more uniform α-Fe. The Fe-C compound is F ₃ C, Fe ₉₃ C ₇ and Fe ₄ C _{0 . And} one or more of ₆₃ .

In addition, according to an embodiment of the present invention, the Fe-based soft magnetic alloy may have a crystallized area value of 70% or less according to Equation 1 below, more preferably 30 to 70%, even more preferably 50 to May be 70%.

[Equation 1]

In this case, the area refers to an integral value for the crystalline region or the amorphous region measured during X-ray diffraction (XRD) analysis at a 10 to 90 ° angle (2θ) for the Fe-based soft magnetic alloy.

As the crystallized area value satisfies 70% or less, crystals of α-Fe and Fe and other intermetallic compounds such as Fe-C-based compounds are produced at an appropriate ratio, which may be more advantageous to satisfy the desired physical properties. Can be. If the crystallized area value exceeds 70%, the formation of compound crystals between other metals, such as Fe-C compounds, may be greatly increased, thereby preventing the desired level of physical properties from being expressed. In addition, the crystallized area value is preferably 30% or more, but less than 30% may also not satisfy the level of the desired magnetic properties.

The Fe-based soft magnetic alloy included in the above-described embodiment of the present invention may be manufactured by the manufacturing method described below, but is not limited thereto.

Fe-based initial alloy included in an embodiment of the present invention after the melting of the Fe-based alloying composition or Fe-based master alloy mixed with a base material containing each element is weighed to have the composition of the empirical formula of the Fe-based alloy described above It can be prepared by quench solidification. The shape of the Fe-based initial alloy prepared according to the specific method used during the quench solidification may vary. As the method used for the quench solidification, a conventionally known method can be adopted, and the present invention is not particularly limited thereto. However, as a non-limiting example, the quench solidification is powdered through the high pressure gas (Ex. Ar, N ₂ , He, etc.) and / or high pressure water to which the molten Fe-based alloy or Fe-based alloying composition is injected Gas injection method (automizing method), a centrifugal method for producing a powder phase using a disk that rotates the molten metal rapidly, a melt spinning method for producing a ribbon by a roll that rotates at a high speed. 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 in 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 may be manufactured into a bulk amorphous alloy through a commonly known method, for example, a coalescence method and a solidification method. As a non-limiting example for the coalescence method, methods such as shock consolidation, explosive forming, sintering, hot extrusion and hot rolling can be used. In the impact coalescing method, the impact coalescing method applies a shock wave to the powder-alloy polymer so that waves are transmitted along the grain boundary and energy absorption occurs at the particle interface, whereby the absorbed energy forms a fine molten layer on the particle surface. By forming the bulk amorphous alloy can be produced. At this time, the resulting molten layer should be cooled fast enough to maintain an amorphous state through heat transfer into the particles. Through this method, bulk amorphous alloys having a packing density of up to 99% of the intrinsic density of amorphous alloys can be prepared and have an advantage of obtaining sufficient mechanical properties. In addition, the hot extrusion and rolling method is to use the fluidity of the amorphous alloy at a high temperature to heat the amorphous alloy powder to a temperature near Tg, and to roll, and to form a bulk amorphous alloy having sufficient density and strength by quenching after rolling. Can be. On the other hand, the solidification method may include copper mold casting, high pressure die casting, arc melting, unidirectional melting, squeez casting, strip casting, and the like. As each method can employ well-known methods and conditions, the present invention is not particularly limited thereto. For example, the copper alloy mold casting method is to inject the molten metal to the copper mold having a high cooling ability by using a pressure difference between the inside and the outside of the mold to inject the molten metal into the inside of the mold or by applying a constant pressure from the outside. As a method using a pressing method, a molten metal injected into a copper mold at high speed by pressurization or suction is solidified to produce a Fe-based initial alloy having a constant bulk shape.

Next, heat treatment may be performed on the prepared Fe-based initial alloy.

The heat treatment is a step of transforming the atomic arrangement of the Fe-based initial alloy from amorphous to crystalline, it is possible to produce nano-crystals containing α-Fe through the heat treatment. However, as the size of the crystal produced according to the temperature, the temperature increase rate, and / or treatment time, etc., which are heat-treated in the second step may be grown to a desired level or more, adjustment of the heat treatment conditions is very important in controlling the grain size. In particular, the composition of the Fe-based initial alloy according to the present invention does not contain elements such as Nb, which serves as a barrier that can prevent the growth of crystal size, and therefore, under normal heat treatment conditions, the desired level, for example, 30 nm Below, preferably 25 nm or less, it may be very difficult to make the nanocrystalline grains, and if a large amount of time and effort is put into the grains, mass production may be difficult.

In order to solve this problem, the heat treatment may be performed at a temperature of 80 to 120%, more preferably 95 to 110% of the heat treatment reference temperature according to Equation 2 below, and through this, a nano having a desired particle size Grain can be produced.

[Equation 2]

If heat treatment is performed at less than 80% of the heat treatment reference temperature calculated according to Equation 2, nanocrystal grains may not be produced at a desired level. In addition, if heat treatment is performed at a temperature exceeding 120% of the heat treatment reference temperature, the grain size of the crystals produced in the alloy may be coarsened, and the grain size distribution of the crystals formed may be widened, thereby decreasing the uniformity of the grain size. In addition, crystals of Fe and other intermetallic compounds other than α-Fe may be excessively produced to obtain a uniform nanocrystalline Fe-based alloy of α-Fe.

In addition, according to an embodiment of the present invention, the temperature increase rate up to the heat treatment temperature also has a large influence on the grain size of the generated nano-crystal grains, for example, the temperature increase rate from room temperature to the heat treatment temperature is 80 ℃ / min or less, more Preferably it is 60 degrees C / min or less, More preferably, it is 50 degrees C / min or less, More preferably, it may be 40 degrees C / min or less. Typically, the temperature increase rate in the heat treatment process for transforming from an amorphous alloy to a crystalline alloy is known to be advantageous to obtain a crystal having a uniform particle size at high temperature, for example, 100 ℃ / min or more, Fe-based according to the present invention Unlike the general tendency, the alloy may be advantageously uniformly formed so that the grain size of the resulting crystals may be made close to the average particle diameter only by slowly raising the temperature at a temperature raising rate of 80 ° C./min or less and then performing heat treatment at a desired heat treatment temperature.

This may help to produce a uniform grain size when the temperature rise rate is high, but the Fe-based soft magnetic alloy according to the present invention acts as a barrier for the growth of elements or crystals that help to produce uniform nano grains such as Si element in the composition Since it does not contain the Nb element that performs the so that it is not very easy to enter the fish, it may not be able to enter the fish at the desired level at the elevated temperature. Accordingly, it may be desirable to lower the temperature of 80 ° C / min or lower than the high temperature, and through this to control the crystal size of α-Fe and the formation of the compound between the Fe-C to an appropriate content α of the desired uniform particle diameter It is advantageous to prepare -Fe. In addition, the low temperature increase may be more suitable for mass production, and the manufacturing cost is reduced. If the temperature increase rate exceeds 80 ℃ / min there is a problem that can not control the particle size distribution of the resulting crystal to the desired level. However, it is preferable that the temperature increase rate is 7 ° C./min or more, and if the temperature is raised at a rate of less than 7 ° C./min, the heat treatment time is prolonged, the grain size becomes very uneven due to the prolonged heat treatment time, and coarse grains are precipitated. There is a concern that it can be.

In addition, the heat treatment time at the heat treatment temperature in the second step may be performed for 30 seconds to 1 hour. The heat treatment time may be changed according to the heat treatment temperature to be performed, but if the heat treatment is less than 30 seconds, the transformation into crystalline may not be achieved at a desired level, and if the heat treatment is performed for more than 1 hour, the crystal is produced. There is a problem of coarse grain size.

Meanwhile, the second step may be performed by adding a pressure and / or a magnetic field in addition to heat. Such additional processing can be used to produce crystals with magnetic anisotropy in a particular one direction. In this case, the applied pressure or the degree of the magnetic field may vary depending on the degree of the desired physical property, and the present invention is not particularly limited thereto.

The Fe-based soft magnetic alloy according to the embodiment of the present invention described above may be implemented by magnetic cores such as winding cores, laminated cores, green powder cores, or magnetic field shielding members.

In addition, the magnetic core may be implemented as a coil component together with a coil wound outside of the magnetic core to perform a magnetic core function, and the coil component may be applied to components such as a laser, a transformer, an inductor, a motor or a generator. .

In addition, the magnetic shielding member may be provided on an antenna unit including an antenna, for example, an antenna performing a function such as wireless charging, short-range communication, magnetic security transmission, etc., and may serve to improve the antenna characteristics. In this case, the Fe-based soft magnetic alloy provided in the magnetic shielding member may be fragmented to reduce the magnetic loss caused by the eddy current, and to support the fragments between the fragments, and to further reduce the magnetic loss caused by the eddy current. The layer may penetrate and insulate each fragment. At this time, the particle diameter of the fragments may be 0.1㎛ ~ 5㎜ but is not limited thereto.

Although the present invention will be described in more detail with reference to the following examples, the following examples are not intended to limit the scope of the present invention, which will be construed as to aid the understanding of the present invention.

<Example 1>

Experimental Fe _{85 . 3} B ₁₀ C ₄ Cu _{0 .7,} the initial alloy is rapidly cooled the raw material for the production through the melt spinning after having been melted by the arc melting method was about 20㎛, the thickness range of about 2㎜ the ribbon in the Ar atmosphere 60m / Fe-based soft magnetic initial alloy was prepared at a speed of s. The prepared initial alloy was heat treated at a temperature rising rate of 10 ° C./min at room temperature, and then heat treated at 346 ° C. for 10 minutes to produce a Fe-based soft magnetic alloy as shown in Table 1 below.

<Examples 2 to 6>

The preparation was carried out in the same manner as in Example 1, but the Fe-based soft magnetic alloy was prepared as shown in Table 1 by changing the heat treatment rate of heating as shown in Table 1 below.

Comparative Example 1

It was prepared in the same manner as in Example 1, but the composition of the alloy was changed as shown in Table 1 to produce a Fe-based soft magnetic alloy as shown in Table 1.

Experimental Example 1

The following physical properties of the Fe-based soft magnetic alloys prepared in Examples and Comparative Examples were evaluated and shown in Table 1.

1. Analysis of crystal structure, maximum grain size, average grain size and crystallized area value

In order to evaluate the crystal structure, crystal maximum grain size and crystallized area of the alloy, XRD patterns through X-ray diffraction, SAD patterns and TEM through limited field electron diffraction were analyzed.

In addition, the crystallized area value was calculated through the following equation (1).

[Equation 1]

In this case, the area refers to an integral value for the crystalline region or the amorphous region measured during X-ray diffraction (XRD) analysis at a 10 to 90 ° angle (2θ) for the Fe-based soft magnetic alloy.

2. Magnetic property evaluation

In order to calculate the coercive force and the saturation magnetization value, it was evaluated in the magnetic field of 400k A / m by the vibration sample magnetometer (VSM). At this time, the coercive force and saturation magnetization values of the remaining examples and the comparative examples were relatively represented based on the coercive force and the saturation magnetization value of Example 1 as 100%.

			Example 1	Example 2	Example 3	Example 4	Example 5	Example 6	Comparative Example 1
Initial alloy	Experimental formula	a 1)	85.3	85.3	85.3	85.3	85.3	85.3	85.3
		b 2)	10	10	10	10	10	10	14
		c 3)	4	4	4	4	4	4	0
		d 4)	0.7	0.7	0.7	0.7	0.7	0.7	0.7
		b + c	14	14	14	14	14	14	14
	Crystal phase		Amorphous	Amorphous	Amorphous	Amorphous	Amorphous	Amorphous	Mixed
Heat treatment temperature (℃) / temperature increase rate (℃ / m)			346/10	346/35	346/45	346/75	346/85	346/4	346/10
Alloy after heat treatment	Crystal phase		Mixed	Mixed	Mixed	Mixed	Mixed	Mixed	Mixed
	decision	Average particle diameter (nm)	28	28	27	25	24	30	160
		Particle size (nm)	34	33	38	53	106	88	354
		% Of crystallized area	52	53	59	68	75	47	89
	Saturated magnetic flux density (%)		100	101	103	103	104	98	84
	Coercivity (%)		100	102	109	122	150	121	197
1) a: at% of Fe in the alloy 2) b: at% of B in the alloy 3) c: at% of C in the alloy 4) d: at% of Cu in the alloy 5)

As can be seen from Table 1 above,

In Comparative Example 1, as the carbon was not included, crystals were formed in the initial alloy, thereby making it impossible to prepare an amorphous alloy.

In addition, in Example 5 in which the heat treatment rate was exceeded in the preferred range of the present invention, crystal grains having a small average particle diameter were produced, but crystals having a maximum particle diameter of 106 nm were generated, and thus the coercive force was applied to other examples. It can be seen that the increase significantly.

On the other hand, in the four-element composition according to the present invention through the results of Example 5, even though it is possible to obtain nanocrystals having a small average particle diameter at a typical high temperature increase rate, it is difficult to produce crystal grains of uniform particle size, You can see that there are things that are not.

Although one embodiment of the present invention has been described above, the spirit of the present invention is not limited to the embodiments set forth herein, and those skilled in the art who understand the spirit of the present invention, within the scope of the same idea, the addition of components Other embodiments may be easily proposed by changing, deleting, adding, and the like, but this will also fall within the spirit of the present invention.

Claims (3)

1. A Fe-based soft magnetic alloy represented by the empirical formula Fe _a B _b C _c Cu _d and comprising metal compounds formed between α-Fe and at least one of Fe and B, C and Cu:

   However, in the empirical formula, a, b, c and d are at% (atomic percent) of the corresponding element, 78.5≤≤a≤≤87.0, 12≤≤b + c≤≤21, 0.5≤d≤≤1.5.
2. The method of claim 1,

   The Fe-based soft magnetic alloy is a Fe-based soft magnetic alloy having a crystallized area value of 70% or less according to Equation 1 below:

   [Equation 1]

   

   In this case, the area refers to an integral value for the crystalline region or the amorphous region measured during X-ray diffraction (XRD) analysis at a 10 to 90 ° angle (2θ) for the Fe-based soft magnetic alloy.
3. The method of claim 2,

   The Fe-based soft magnetic alloy is a Fe-based soft magnetic alloy having an average particle diameter of 18 ~ 30nm, the maximum grain size of 50nm or less in the crystal grains.

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