Amorphous alloy and magnetic powder containing the same

Abstract

Embodiments of the present invention provide an amorphous alloy capable of simultaneously achieving high saturation magnetization and low iron loss characteristics. According to embodiments of the present invention, the prepared powder exhibits excellent sphericity, high saturation magnetization and magnetic flux density, and low iron loss, thus making it suitable for use as a core material for power conversion devices, inductors, or transformers.

Description

[Technical Field]

[0001] This invention relates to an amorphous alloy, and more specifically, to an amorphous alloy capable of simultaneously achieving high saturation magnetization and low core loss. [Previous Technology]

[0002] As a new type of energy-saving and environmentally friendly soft magnetic material, iron-based amorphous alloys have the characteristics of being free of grains and grain boundary defects and having low magnetic anisotropy, thus exhibiting excellent properties such as high magnetic permeability, high saturation magnetization, high resistivity, low coercivity and low loss.

[0003] In iron-based amorphous composite materials, due to their grainless structure, their magnetic properties are less susceptible to directional influences, thereby further reducing the alloy's magnetic anisotropy and magnetostriction effect. As a result, this material possesses high saturation magnetization and high permeability, and is therefore widely used in various fields such as power, electronics, and information transmission and conversion.

[0004] However, in the Fe-Si-BC amorphous alloys developed in the past, it is difficult to obtain iron-based alloys with a saturation magnetic flux density greater than 1.5 Tesla and low iron loss characteristics at the same time.

[0005] Furthermore, even if an iron-based alloy with a saturation magnetic flux density greater than 1.5 Tesla is prepared, if the alloy contains a crystalline phase, it will lead to an increase in the coercive force and the generation of eddy currents, making it difficult to obtain low iron loss characteristics.

[0006] On the other hand, since high iron loss can have an adverse effect on the efficiency of inductors, it is essential to ensure the amorphous properties of iron-based alloys when they are prepared.

[0007] In order to solve the above problems, attempts have been made to adjust the alloy composition by adding a variety of elements, but it is still difficult to achieve a saturation magnetic flux density greater than 1.5 Tesla while satisfying the low iron loss characteristics.

[0008] [Prior Art Documents] [Patent Documents] Patent Document 0001: Chinese Patent Publication CN 108251765 A. [Summary of the Invention]

[0009] [The problem the invention aims to solve]

[0010] The purpose of this invention is to provide an Fe-Si-BPC amorphous alloy with an optimized composition ratio as a method to solve the above-mentioned problems of the prior art. This alloy has low iron loss characteristics and exhibits high saturation magnetic flux density. Specifically, the saturation magnetic flux density is above 1.5 Tesla and can meet the requirements of low iron loss.

[0011] The technical problems to be solved by the present invention are not limited to the technical problems mentioned above. For other technical problems not explicitly described, those skilled in the art can understand them clearly based on the following description.

[0012] [Methods used to solve problems]

[0013] An embodiment of the present invention provides an amorphous alloy with high saturation magnetization.

[0014] The amorphous alloy according to an embodiment of the present invention is characterized in that, expressed by the chemical composition Fe100₋₍a₊b₊c₊d₎SiABbPcCd, the atomic percentage of each element satisfies the following conditions: 3.5 at% ≤ a ≤ 6.5 at%, 7.5 at% ≤ b ≤ 11 at%, 0.3 at% ≤ c ≤ 1.8 at%, 2.8 at% ≤ d ≤ 6.2 at%.

[0015] In an embodiment of the present invention, b can be 7.8 at% ≤ b ≤ 10.8 at%.

[0016] In an embodiment of the present invention, b can be 0.5 at% ≤ c ≤ 1.5 at%.

[0017] In an embodiment of the present invention, b can be 3.0 at% ≤ d ≤ 6.0 at%.

[0018] In an embodiment of the present invention, b, c and d can satisfy the following relationship: 0.05 ≤ c / (b + c + d) ≤ 0.1.

[0019] In an embodiment of the present invention, b, c and d can satisfy the following relationship: 0.2 ≤ d / (b + c + d) ≤ 0.4.

[0020] In an embodiment of the present invention, the saturation magnetization of the amorphous alloy can be 175 emu / g or higher.

[0021] In an embodiment of the present invention, the saturation magnetic flux density of the amorphous alloy can be 1.5T or higher.

[0022] In an embodiment of the present invention, b, c and d can satisfy the following relationship: 14.5 ≤ b + c + d ≤ 15.

[0023] In order to solve the problems of the prior art, another embodiment of the present invention may provide a magnetic powder comprising the amorphous alloy.

[0024] [Effects of the Invention]

[0025] According to an embodiment of the present invention, the amorphous alloy has the following effects.

[0026] (1) Improvement of powder sphericity

[0027] By adding an appropriate amount of phosphorus (P), the sphericity of the powder is improved, thereby increasing the powder's packing density. In this way, a higher forming density can be achieved during the manufacturing process of the iron core, thereby enabling both a higher magnetic flux density and a lower iron loss.

[0028] (2) Increase in saturation magnetization and magnetic flux density

[0029] The saturation magnetization (Ms) is increased to over 175 emu / g, and the magnetic flux density (Bs) is also increased to over 1.5 T. This property allows for higher magnetic flux to pass through the iron core of the same volume, thereby contributing to the miniaturization of the iron core.

[0030] (3) Reduction of iron loss

[0031] The powder prepared from the alloy of the present invention achieves a 10% to 15% reduction in iron loss compared with traditional amorphous magnetic powder, which is of great help in reducing heat generation and energy loss under high-frequency operating conditions.

[0032] (4) Improvement of DC overlap characteristics

[0033] Compared to traditional amorphous magnetic powders, the DC overlap characteristic is improved by approximately 5% to 7%, which means improved DC bias characteristics in applications such as inductors. Since the magnetization change caused by DC current is smaller, it is beneficial for the design of small inductors.

[0034] Furthermore, since the amorphous alloy described in the embodiments of the present invention has the above-mentioned excellent effects, it has the characteristics of being usable as a core material for power conversion devices such as high-frequency switching power supplies (SMPS), inductors, or transformers.

[0035] The effects of the present invention are not limited to those described above, but should be understood to include all effects that can be derived from the inventive concept described in the detailed description of the present invention or the claims.

Implementation Method

[0036] The present invention will now be described with reference to the accompanying drawings. However, the present invention can be implemented in many different forms and should not be limited to the embodiments set forth in this specification. In addition, for the purpose of clearly illustrating the present invention, parts unrelated to the description have been omitted in the drawings, and similar element symbols have been used for similar parts throughout the specification.

[0037] In this specification, when a part is referred to as being “connected to (joined to, contacted to, or coupled to)” another part, the part may be “directly connected” to the other part or may be “indirectly connected” with other components disposed therebetween. Furthermore, when a part “contains” certain constituent elements, unless specifically stated to the contrary, it should be understood that other constituent elements are not excluded, but rather that more constituent elements may be included.

[0038] The terminology used in this specification is for illustrative purposes only and is not intended to limit the invention. Unless the context otherwise requires, singular terms should be understood to include their plural forms as well. In this specification, the terms "comprising" or "having," etc., should be interpreted as indicating the presence of the described features, values, steps, operations, components, parts, or combinations thereof, and should not be construed as excluding the possibility of the presence or addition of one or more other features, values, steps, operations, components, parts, or combinations thereof.

[0039] The embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0040] The purpose of this invention is to provide an iron-based amorphous alloy with high magnetic flux density, low iron loss and excellent DC bias characteristics.

[0041] An embodiment of the present invention describes an amorphous alloy with high saturation magnetization, characterized in that the amorphous alloy is represented by the chemical composition Fe100₋₍a₊b₊c₊d₎SiaBbPcCd.

[0042] In the amorphous alloy described in the embodiments of the present invention, the Fe content can be in the range of 74.5 at% to 85.9 at%, more preferably 75.2 at% to 85.2 at%, and most preferably 78 at% to 85.2 at%. The above-mentioned higher Fe content helps to improve the saturation magnetic flux density characteristics of the amorphous alloy.

[0043] On the other hand, in the embodiments of the present invention, the combined addition of quasi-metallic elements Si and B and non-metallic elements P and C can improve the corrosion resistance, heat resistance and mechanical properties of iron-based amorphous alloys, especially playing an important role in inhibiting crystal growth and promoting amorphous formation.

[0044] Specifically, Si (silicon) helps minimize the internal stress of the powder and improve magnetic properties while maintaining amorphous properties, thereby promoting the improvement of magnetic flux density and saturation magnetization. In the amorphous alloy composition of the present invention, the Si content can be 3.5 at% ≤ a ≤ 6.5 at%, more preferably 4 at% ≤ a ≤ 6 at%.

[0045] Furthermore, boron (B) can improve the amorphous formation capability, allowing magnetic domains to move more freely, thereby helping to reduce iron loss. In the above alloy composition, the B content can be 7.5 at% ≤ b ≤ 11 at%, more preferably 7.8 at% ≤ b ≤ 10.8 at%. By controlling the boron content within the above range, the amorphous structure can be stabilized, thereby increasing the magnetic flux density (Bs) and saturation magnetization (Ms).

[0046] Phosphorus (P) is added to improve thermal stability and sphericity of the amorphous powder. Increased sphericity improves powder filling rate and increases forming density during core manufacturing, thereby reducing iron loss. In the above alloy composition, the P content can be 0.3 at% ≤ c ≤ 1.8 at%, more preferably 0.5 at% ≤ c ≤ 1.5 at%. By controlling the phosphorus content within the above range, a higher forming density can be achieved, thereby simultaneously achieving higher magnetic flux density and lower iron loss.

[0047] Carbon (C) plays a role in inhibiting crystallization in high-content iron-based alloys. In the above alloy composition, the C content can be 2.8 at% ≤ d ≤ 6.2 at%, more preferably 3.0 at% ≤ d ≤ 6.0 at%. By controlling the carbon content within the above range, crystallization can be inhibited under relatively high Fe content conditions, thereby ensuring amorphous properties and helping to improve saturation magnetization.

[0048] Furthermore, in embodiments of the present invention, b, c, and d can satisfy one of the following conditions: First condition: 0.05 ≤ c / (b + c + d) ≤ 0.1, Second condition: 0.2 ≤ d / (b + c + d) ≤ 0.4, Third condition: 14.5 ≤ b + c + d ≤ 15. Alternatively, any two of the above three conditions can be satisfied simultaneously; optimally, all three conditions are satisfied simultaneously.

[0049] Amorphous alloys that meet the above conditions can achieve high saturation magnetization while helping to reduce iron loss, thereby making it easier to achieve the purpose of the present invention. However, the present invention is not limited to the above conditions.

[0050] According to an embodiment of the present invention, the saturation magnetization of the amorphous alloy can be 175 emu / g or higher.

[0051] In addition, the saturation magnetic flux density of the amorphous alloy can be above 1.5T.

[0052] In order to solve the problems of the prior art, another embodiment of the present invention may provide a magnetic powder comprising the amorphous alloy.

[0053] The alloy of the present invention and the magnetic powder contained herein have the following effects.

[0054] (1) Improvement of powder sphericity

[0055] The addition of an appropriate amount of phosphorus (P) improves the sphericity of the powder, thereby increasing the powder's packing density. As a result, a higher forming density can be achieved during the core manufacturing process, thereby simultaneously achieving a higher magnetic flux density and lower iron loss.

[0056] (2) Increase in saturation magnetization and magnetic flux density

[0057] The saturation magnetization (Ms) is increased to over 175 emu / g, and the magnetic flux density (Bs) is also increased to over 1.5 T. This allows for higher magnetic flux to pass through the iron core of the same volume, thereby contributing to the miniaturization of the iron core.

[0058] (3) Reduction of iron loss

[0059] The powder prepared from the alloy of the present invention achieves a 10% to 15% reduction in iron loss compared with traditional amorphous magnetic powder, which is of great help in reducing heat generation and energy loss under high-frequency operating conditions.

[0060] (4) Improvement of DC overlap characteristics

[0061] Compared to traditional amorphous magnetic powders, the DC overlap characteristic is improved by approximately 5% to 7%, which means that the DC bias characteristics are improved in applications such as inductors. Since the magnetization change caused by DC current is smaller, it is beneficial for the design of small inductors.

[0062] The alloy and magnetic powder described in the embodiments of the present invention are particularly suitable as core materials for power conversion devices such as high-frequency switching power supplies (SMPS). Their low iron loss characteristics help reduce heat generation and improve operating efficiency during high-frequency operation.

[0063] In addition, based on the high magnetic flux density and low iron loss, miniaturization and high efficiency can be achieved, making it suitable for inductor applications.

[0064] In addition, it can maintain low loss even under high frequency operating conditions, so it is suitable for core materials of small transformers.

[0065] The present invention will be described in more detail below through preparation examples, comparative examples and experimental examples, but the present invention is not limited to the preparation examples and experimental examples described below.

[0066] Preparation Example

[0067] Fe-Si-BPC amorphous alloys were prepared according to the examples and comparative examples.

[0068] Table 1 below shows the atomic percentage of each metal element in the prepared alloy.

[0069] [Table 1] distinguish Fe Si B P C B+P+C P / (B+P+C) C / (B+P+C) Example 1 80.25 5.00 7.97 0.95 5.83 14.75 0.064 0.395 Example 2 80.25 5.00 8.38 0.77 5.60 14.75 0.052 0.380 Example 3 80.25 5.00 9.29 1.08 4.38 14.75 0.073 0.297 Example 4 80.25 5.00 9.77 1.21 3.77 14.75 0.082 0.256 Example 5 80.25 5.00 10.15 0.88 3.72 14.75 0.060 0.252 Example 6 80.25 5.00 10.62 1.02 3.11 14.75 0.069 0.211 Comparative Example 1 78.88 5.93 13.21 0.00 1.98 15.19 0.000 0.130 Comparative Example 2 77.19 5.93 7.18 2.50 7.20 16.88 0.148 0.427 Comparative Example 3 80.25 5.00 8.28 0.23 6.24 14.75 0.016 0.423 Comparative Example 4 80.25 5.00 10.03 2.01 2.71 14.75 0.136 0.184 Comparative Example 5 80.25 5.00 13.50 0.61 0.64 14.75 0.041 0.043 Comparative Example 6 80.25 5.00 11.25 3.50 0.00 14.75 0.237 0.000 Comparative Example 7 80.25 5.00 7.16 0.00 7.59 14.75 0.000 0.515

[0070] Practical example

[0071] The experimental characteristics of the metallic magnetic powders prepared in the examples and comparative examples were analyzed.

[0072] The saturation magnetization (Ms) was measured using equipment from LakeShore, and the saturation flux density (Bs) was calculated in conjunction with the density.

[0073] The sphericity was measured using equipment from MICROTRAC and the average value was presented in a chart after being classified according to the particle size range (10-50 μm).

[0074] Magnetic core loss (unit: mW / cc) refers to the energy loss generated when an alternating magnetic field (AC field) is applied, and is measured under the conditions of a frequency of 1 MHz and a magnetic induction intensity of 20 mT.

[0075] The sample used for measurement was a toroidal core, formed by pressing at a density of 1.65 ton / cm². 25 wt% CIP (carbonyl iron powder) and 3 wt% binder were added to the amorphous alloy powder to determine its magnetic property changes.

[0076] The DC characteristics are formed by winding the magnetic core with the above method and applying a current of up to 40A, and measuring the percentage decrease in L value (permeability) using an LCR meter.

[0077] Figure 1 is a graph showing the sphericity of Example 1, Comparative Example 1 and Comparative Example 2 in terms of particle size range.

[0078] Referring to FIG1, it can be seen that the magnetic powder according to the embodiment of the present invention has a high sphericity. This is mainly because, in Example 1, by controlling the phosphorus content within an appropriate composition range, a higher molding density was achieved compared with Comparative Example 1, which has a lower phosphorus content, and Comparative Example 2, which has a higher phosphorus content.

[0079] Figure 2 is a graph showing the magnetic flux density (Bs) of Example 1, Comparative Example 1, and Comparative Example 2. It can also be seen that the magnetic flux density of Comparative Example 1 and Comparative Example 2 is lower than that of the embodiment of the present invention. This is mainly because the present invention achieves a higher magnetic flux density by adjusting the contents of Si, B, P, and C under specific conditions and within a certain range.

[0080] Figure 3 is a graph showing the core loss of Example 1, Comparative Example 1, and Comparative Example 2. It can also be seen that the core loss of Comparative Example 1 and Comparative Example 2 is greater than that of the embodiment of the present invention. This is mainly because the present invention achieves lower core loss by controlling the content of Si, B, P, and C under specific conditions and within a certain range.

[0081] Figure 4 is a graph showing the DC bias characteristics of Example 1, Comparative Example 1, and Comparative Example 2. It can also be seen that the DC bias characteristics of the embodiments of the present invention are improved compared with the comparative examples by adjusting the contents of Si, B, P, and C under specific conditions and ranges.

[0082] Table 2 below is a table showing the sphericity, amorphous properties, Ms (saturation magnetization), Bs (magnetic flux density), iron loss, DC overlap characteristics, etc. of the powder containing the alloy in the embodiments and comparative examples of the present invention.

[0083] Referring to Table 2, it can be seen that the amorphous alloy powder according to the embodiments of the present invention can maintain amorphous properties and has excellent magnetic properties and lower iron loss compared with the comparative example.

[0084] [Table 2] distinguish sphericity Amorphous properties Ms (g / emu) Bs (T) Iron loss (mW / cc) DC overlap Example 1 0.970 amorphous 176.8 1.58 343 7% ↑ Example 2 0.969 amorphous 175.8 1.58 353 5% ↑ Example 3 0.972 amorphous 177.9 1.60 361 7% ↑ Example 4 0.975 amorphous 178.1 1.60 368 7% ↑ Example 5 0.969 amorphous 176.3 1.58 348 6% ↑ Example 6 0.971 amorphous 176.5 1.59 425 6% ↑ Comparative Example 1 0.953 amorphous 166.5 1.50 425 - Comparative Example 2 0.965 amorphous 161.5 1.47 392 - Comparative Example 3 0.955 Amorphous / Crystal 178.5 1.60 548 - Comparative Example 4 0.957 Amorphous / Crystal 177.6 1.59 518 - Comparative Example 5 0.961 Amorphous / Crystal 177.5 1.59 495 - Comparative Example 6 0.968 Amorphous / Crystal 176.8 1.59 477 - Comparative Example 7 0.970 Amorphous / Crystal 178.2 1.60 523 -

[0085] The above description of the present invention is merely illustrative. Those skilled in the art should understand that modifications can be easily made in other specific forms without altering the technical concept or essential features of the present invention. Therefore, the embodiments described above should be understood as exemplary only and not restrictive. For example, the constituent elements described in a single form can be implemented in a distributed manner, and similarly, the constituent elements described in a distributed manner can be implemented in a combined manner.

[0086] The scope of protection of the present invention is determined by the scope of the patent application described below. It should be understood that the meaning and scope of the scope of the patent application, as well as all changes or modifications derived from its equivalent concepts, should be included within the scope of protection of the present invention. [Simplified Explanation of the Diagram]

[0087] Figure 1 is a graph showing the sphericity corresponding to the particle size distribution of Example 1, Comparative Example 1 and Comparative Example 2.

[0088] Figure 2 is a graph showing the Bs (magnetic flux density) of Example 1, Comparative Example 1 and Comparative Example 2.

[0089] Figure 3 is a graph showing the core loss of Example 1, Comparative Example 1 and Comparative Example 2.

[0090] Figure 4 is a graph showing the test results of the DC bias characteristics of Example 1, Comparative Example 1 and Comparative Example 2.

Claims

1. An amorphous alloy, wherein the amorphous alloy is a Fe-Si-BPC amorphous alloy with high saturation magnetization, characterized in that the amorphous alloy has a chemical composition of Fe100₋₍a₊b₊c₊d₎SiaBbPcCd, wherein, The atomic percentage of each element satisfies the following condition: 3.5 at% ≤ a ≤ 6.5 at%, 7.5 at% ≤ b ≤ 11 at%, 0.3 at% ≤ c ≤ 1.8 at%, 2.8 at% ≤ d ≤ 6.2 at%, where b, c, and d satisfy the following relationships: 0.05 ≤ c / (b+c+d) ≤ 0.1, 0.2 ≤ d / (b+c+d) ≤ 0.4, 14.5 ≤ b+c+d ≤ 15.

2. The amorphous alloy as described in claim 1, wherein, The condition b satisfies 7.8 at% ≤ b ≤ 10.8 at%.

3. The amorphous alloy as described in claim 1, wherein, The condition c satisfies 0.5 at% ≤ c ≤ 1.5 at%.

4. The amorphous alloy as described in claim 1, wherein, The condition d satisfies 3.0 at% ≤ d ≤ 6.0 at%.

5. The amorphous alloy as described in claim 1, wherein, The saturation magnetization of the amorphous alloy is above 175 emu / g.

6. The amorphous alloy as described in claim 1, wherein, The saturation magnetic flux density of the amorphous alloy is above 1.5T.

7. A magnetic powder comprising the amorphous alloy as described in claim 1.

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