KR101607483B1 - Fe-based Amorphous Alloy Power And Fe-based Nano-Crystallization Amorphous Compressed Power Core Using the same - Google Patents

Abstract

As an alloy composition of the composition formula Fe _a Si _b B _c P _x Nb _y Cu _z as the starting material of the nanocrystalline alloy developed in the present invention, 77? A? 83at%, 8 <b? 13at%, 6? , 0.5? X? 2.0at%, 0.5? Y? 2.0at%, 0.5? Z? 2.0at%, b + 2c? 11.0at%, c + x? 7.0at%.
The amorphous alloy powder of this composition is produced by high pressure water dispersion method and rapid solidification method and the saturation velocity density of the prepared powder is 1.5T or more. By using this powder, Value of less than 300 mW / cc at 50 kHz and 1000 Gauss, and a nanocrystalline pressure molecular core of 150 or more at an effective permeability of 100 kHz, which was impossible at the time of conventional room temperature molding, can be produced.

Description

   Iron-based amorphous alloy powder and iron-based nanocrystalline pressure molecular core using the same. The present invention relates to a Fe-based amorphous alloy powder,

The present invention relates to an Fe-based amorphous (nano-crystal) alloy suitable for use in transformers, inductors and the like, and a manufacturing method thereof.

   The Fe-Si-B-Nb-Cu soft magnetic alloy developed by Yoshizawa et al. Has a very high effective magnetic permeability and high loss at high frequency. However, since the saturation magnetic flux density (Bs) It is difficult to apply it to a component for a large current when it is applied as a pressurized core core. This is described in the document 1.

[Paper 1] J. Appl. Phys., 64 (1988), 6444

   On the other hand, the Fe-B-Si-P-C-Cu system developed by Makino has a saturation magnetic flux density higher than 1.6T, but has a disadvantage of high loss at high frequencies. This is described in Patent Document 2

[Patent Document 2] Korean Unexamined Patent Publication No. 10-2011-0044832

Accordingly, an object of the present invention is to provide an amorphous (nanocrystalline) alloy having a high magnetic flux density of 1.5 T or more, which is applicable to high current applications, and a high frequency loss and a method of manufacturing the same.

    The present invention has found that a specific alloy composition can be used as a starting material for obtaining an Fe-based nanocrystalline alloy powder having a high magnetic flux density of 1.5 T or more and a high magnetic permeability. Here, the specific alloy composition has a predetermined composition formula, has an amorphous phase as a main phase, and has excellent high frequency loss. When the specific alloy composition is heat-treated at a crystallization temperature or higher, nanocrystalline water having a bcc structure can be precipitated. These nanocrystalline alloys greatly reduce coercivity by greatly reducing saturation magnetostriction, thereby providing high saturation flux density, high permeability, and low RF loss values.

In the present invention, the starting material of the nanocrystalline alloy is an alloy composition of _a composition formula Fe _a Si _b B _c P _x Nb _y Cu _z , wherein 77? A? 83at%, 8 <b? 13at%, 6? C? It is preferable that the following conditions are satisfied: 0.5? X? 2.0at%, 0.5? Y? 2.0at%, 0.5? Z? 2.0at%, b + 2c? 11.0at%, c + x? 7.0at%.

  In the alloy composition, the Fe element is a main element and is an essential element responsible for magnetism. Basically, it is preferable that the proportion of Fe is high in order to increase the saturation magnetic flux density and to reduce the raw material cost. When the Fe content is lower than 77 at%, the saturation flux density value is lowered to 1.5 T or lower, and when the Fe content is higher than 83 at%, it becomes difficult to form an amorphous phase under quenching conditions.

  The Si element in the alloy composition is an essential element for the formation of an amorphous phase and the improvement of a soft magnetic characteristic. If the ratio of Si is less than 8 at%, the soft magnetic characteristics deteriorate. If the proportion of Si is more than 13 at%, the composition ratio of Fe becomes less than 77 at% and the saturation magnetic flux density becomes as low as 1.5 T or less.

  In the alloy composition, element B is an essential element responsible for amorphous phase formation.

When the ratio of B is less than 6 at%, it is difficult to form a uniform amorphous phase, and when it exceeds 10 at%, the saturation magnetic flux density is decreased.

  In the alloy composition, the P element is an essential element responsible for the formation of the amorphous phase. In the present embodiment, by using a combination of Si, B and P elements, amorphous phase forming ability is improved by a much smaller addition amount as compared with the case where only one of them is used. If the ratio of P is less than 0.5 at%, the ability to form an amorphous phase is deteriorated, and if it exceeds 2 at%, the saturation magnetic flux density is deteriorated. From the viewpoint of the combination, the sum of Si + 2B should be at least 11 at%, the amorphous phase forming ability is lowered, and the sum of B + P should be at least 7.0 at%.

  In the alloy composition, the Nb element is an essential element contributing to nanocrystallization. At the formation of the nanocrystalline alloy, coarse nanocrystallization is produced when the Nb content is less than 0.5 at%, and the saturation magnetic flux density is rapidly decreased at more than 2.0 at%.

The above alloy composition is prepared by directly preparing a fine powder by a water pressure method at a high pressure of 30 MPa or higher, or by heat-treating a ribbon produced by a rapid solidification method at a temperature lower than the crystallization temperature and then pulverizing the powder to prepare a powder. In order to evaluate the magnetic properties of the prepared powders, two coatings of phosphoric acid and polyimide were applied to provide insulation and bonding between powders, and then a metal oxide based lubricant which maintains lubricity even at high temperatures was applied, Lt; RTI ID = 0.0 &gt; C, &lt; / RTI &gt; to produce an amorphous pressure molecular core. The molded pressure-sensitive core is heat-treated in a reducing gas atmosphere at a crystallization temperature or more for 30 to 60 minutes.

   In the present invention, amorphous alloy powder having a saturation flux density of 1.5 T or more prepared by a high-pressure water dispersion method and a rapid solidification method was used to produce a pressure-sensitive core by a warm-tempering method at an iron loss value of 300 kW / cc And it is possible to manufacture a pressure-sensitive core of 200 or more at an effective permeability of 100 kHz, which was impossible at the time of conventional room temperature molding.

In addition, the amorphous alloy powder developed by the present invention can greatly increase the molding density by warm-forming, has low permeability due to excellent inter-particle insulating property, has a permeability hardly changed even in a high frequency band, It is possible to manufacture a nanocrystalline pressure molecular core that can be used as a high current magnetic element for electric and electronic devices in the frequency band of from 10 kHz to several tens MHz.

(Example 1)

(Fe) _81.2 Si _9.5 B ₆ P ₁ Nb _1.5 Cu _0.8 Alloy composition (weight%) and then the amorphous alloy powder (having an average particle size of about 70 nm) 15 mu m). Next, in order to evaluate the magnetic properties of the powder, 10 g of phosphoric acid (H ₃ PO ₄ ) was diluted with acetone in 1,000 g of the amorphous alloy powder, dried by a primary coating treatment and then 10 g of polyimide was dissolved in methylene chloride solution , And then subjected to a drying treatment to prepare a powder of composite particles uniformly coated on the surface of the amorphous alloy powder having an average particle size of about 15 μm at a thickness of about 1 μm or less And then 10 g of MoS ₂ powder having an average particle diameter of 3 탆 was uniformly mixed. The blended composite particle powder was automatically charged into a molding die having an outer diameter of 12.7 mm and an inner diameter of 7.65 mm at a rate of 2.50 g in a molding die maintained at 450 ° C. and molded at a pressure of 18 ton / Pressure molecular core was prepared. The molded core was thermally treated at 530 ° C in an argon (Ar) gas atmosphere for 60 minutes to produce a pressure-sensitive core which was nanocrystal in core. Table 1 shows magnetic properties such as effective permeability, saturation magnetic flux density and core loss with respect to the manufactured core.

The first crystallization initiation temperature (T _x1 ) and the second crystallization initiation temperature (T _x2 ) were measured by a differential scanning calorimeter (DSC) using a differential scanning calorimeter (DSC) Speed at a rate of 10 ° C per minute. The saturation magnetic flux density (B _s ) was measured under a magnetic field of 800 kA / m using a vibrating sample type magnetometer (VSM). The effective magnetic permeability was measured by using an impedance analyzer under the external magnetic field of 10 mOe in the frequency band of 100 kHz Measured value. The iron loss value was measured with a BH analyzer under the conditions of a frequency of 50 kHz and an induced magnetic flux density of 1000 Gauss.

(Example 2)

An amorphous alloy ribbon having a width of about 3 mm and a thickness of about 30 탆 was prepared by the rapid solidification method (RSP) of the same alloy composition of Example 1 and then heat-treated for about 30 minutes under a hydrogen gas atmosphere at a temperature of 430 캜, To prepare an amorphous alloy powder having an average particle size of about 30 mu m. Table 1 shows the properties of the prepared nanocrystalline pressure molecular core.

(Example 3-6)

The procedure of Example 1 was repeated, except that the amorphous alloy powder was prepared by quantifying and dissolving the alloy composition of Example 3-4 shown in Table 1 below and then subjecting it to high-pressure water dispersion. Table 1 shows the properties of the prepared nanocrystalline pressure molecular core.

(Comparative Example 1-5)

  The composition was quantified and dissolved so as to have the alloy composition of Comparative Example 1-5 shown in Table 1 below

The procedure of Example 1 was repeated except that the alloy powder was produced by the high-pressure water-dispersion method. Table 1 shows the properties of the prepared nanocrystalline pressure molecular core.

Condition number Amorphous alloy system Powder T _x1 (占 폚) T _x2 (占 폚) Bs (T) Rationality
Investment ratio Iron loss
(mW / cc) Example 1 _{Fe 81 .2 Si 9 .5 B 6} P 1 Nb 1.5 Cu 0 .8 Amorphous 441 588 1.6 275 185 Example 2 _{Fe 81 .2 Si 9 .5 B 6} P 1 Nb 1.5 Cu 0 .8 " 441 588 1.6 280 175 Example 3 _{Fe 77 .7 Si 13 B 6 P} 1 Nb 1 .5 Cu 0 .8 " 449 619 1.5 350 110 Example 4 Fe _{77 .2} Si _{9 .5} B ₁₀ P ₁ Nb _1.5 Cu _{0 .8} " 455 623 1.5 265 165 Example 5 Fe _{81 .2} Si _{8 .5} B ₆ P ₂ Nb _1.5 Cu _{0 .8} " 436 595 1.6 240 210 Example 6 _{Fe 81 .7 Si 9 .5 B 6} P 1 Nb 1.0 Cu 0 .8 " 430 565 1.6 180 230 Example 7 _{Fe 81 .4 Si 9 .5 B 6} P 1 Nb 1.5 Cu 0 .6 " 440 589 1.6 170 265 Comparative Example 1 _{Fe 82 .2 Si 7 B 6 P} 1 Nb 1 .5 Cu 0 .8 " 420 582 1.6 210 425 Comparative Example 2 _{Fe 76 .7 Si 14 B 6 P} 1 Nb 1 .5 Cu 0 .8 " 463 635 1.3 320 135 Comparative Example 3 Fe _{80 .2} Si _{9 .5} B ₅ P ₁ Nb _1.5 Cu _{0 .8} Amorphous + crystal 442 590 1.5 130 750 Comparative Example 4 Fe _{82 .2} Si _{9 .5} B ₆ P ₁ Nb _0.5 Cu _{0 .8} Amorphous 423 546 1.6 125 665 Comparative Example 5 _{Fe 78 .8 Si 9 .5 B 6} P 1 Nb 0.5 Cu 0 .4 Amorphous 423 546 1.5 125 565

   Here, referring to Table 1, the saturation flux density is 1.5T or more and the iron loss value is 300mW / cc or less in the alloy composition range developed in the present invention, and the effective permeability is also in the range of 150-350, It is the permeability value which was not available in molding. On the other hand, as shown in the alloys of the comparative examples, alloys other than the alloying composition of the present invention have a high iron loss when the saturation magnetic flux density is high or a saturation magnetic flux density when the iron loss value is low.

Claims (4)

delete The composition formula _{Fe a Si b B c P x} Nb y Cu _z as an amorphous alloy composition, 77≤a≤83at%, 8 <b≤13at% , 6≤c≤10at%, 0.5 <x≤2.0at%, 0.5 < the sum of Si + 2B in the elements of the composition formula is not less than 11 at%, and the sum of B + P and B + P is not less than 2 at% The amorphous alloy composition is prepared by a high-pressure hydration method or by an amorphous alloy ribbon manufactured by a rapid solidification method, followed by heat treatment at a temperature lower than the crystallization temperature, followed by pulverization to obtain a fine powder Fe-based amorphous alloy powder characterized.
The composition formula _{Fe a Si b B c P x} Nb y Cu _z as an amorphous alloy composition, 77≤a≤83at%, 8 <b≤13at% , 6≤c≤10at%, 0.5 <x≤2.0at%, 0.5 < the sum of Si + 2B in the elements of the composition formula is not less than 11 at%, and the sum of B + P and B + P is not less than 2 at% Amorphous alloy composition is prepared by high-pressure water dispersion method or a rapid solidification method, and amorphous alloy ribbon is prepared by heat-treating the amorphous alloy ribbon at a temperature below the crystallization temperature and then pulverized to obtain an iron- The amorphous alloy powder was diluted by adding phosphoric acid (H ₃ PO ₄ ) in acetone, dried by primary coating treatment, and then subjected to a secondary coating treatment with a solution prepared by dissolving polyimide in methylene chloride solution, Dried to obtain a powder of composite particles in which polyimide is uniformly coated on the surface of the amorphous alloy powder, followed by drying The metal oxide based lubricant is uniformly mixed and then the mixed particle powder is automatically charged into a molding die maintained at 400 ° C to 550 ° C to form a compacted core by a warm- , The inner core of the core is made of nanocrystals by performing the nanocrystallization heat treatment on the prepared core of the pressure-sensitive core above the crystallization temperature, the effective permeability at 100 kHz is 150 to 350, the saturation magnetic flux density is 1.5 T or more, And an iron loss value at 1000 Gauss is 300 mW / cc or less. delete