Amorphous and nanocrystalline soft magnetic alloy ribbon and magnetic core

Abstract

The application relates to the technical field of amorphous nanocrystalline magnetic materials, in particular to an amorphous nanocrystalline soft magnetic alloy ribbon and a magnetic core. f Si a B b Nb c Cu d Ni e Wherein, f, a, b, c, d and e respectively represent the atomic percentage content of corresponding elements, and f+a+b+c+d+e=100, 14<=a<=17, 7.5<=b<=9, a+b>=21.5, 0.5<=e<=3. The amorphous nanocrystalline soft magnetic alloy is formed into nanocrystalline by annealing treatment of the amorphous alloy ribbon. Through control of suitable element composition ratio, the application remarkably improves the magnetic permeability under low, medium and high frequencies, and simultaneously reduces the discreteness of the magnetic permeability under low, medium and high frequencies, so as to meet the application requirement of common mode inductance.

Description

Technical Field

[0001] This invention relates to the field of amorphous and nanocrystalline soft magnetic materials, and particularly to an amorphous and nanocrystalline soft magnetic alloy strip and core. Background Technology

[0002] With the development trend of electronic and power products towards higher frequencies, greater diversity, and higher precision, especially the demand for higher frequency, more diverse, and more refined performance in common-mode inductors, the requirements for nanocrystalline magnetic rings are further increasing, which in turn places higher demands on nanocrystalline tapes. Common-mode inductors are widely used in various fields such as home appliances, automobiles, and photovoltaics. Devices in different fields have different requirements for permeability at various frequency bands, such as from low-frequency 50Hz / 1kHz to mid-frequency applications 10kHz, and then to high-frequency applications 100kHz and higher frequencies. Therefore, it is necessary to take into account the performance at low, medium, and high frequencies.

[0003] Currently, the preparation of nanocrystalline materials falls into two categories: pressure-based tape fabrication and gravity-based tape fabrication. Pressure-based tape fabrication is characterized by thick tapes, typically greater than 22 μm. The performance characteristics of this type of tape are: high performance at low frequencies (permeability >150,000, even reaching 180,000 at 1kHz), but poor performance at 10kHz and 100kHz (permeability <80,000 at 10kHz and <20,000 at 100kHz). The permeability decreases significantly from 1kHz to 10kHz to 100kHz, making it impossible to simultaneously achieve good performance across low, medium, and high frequencies. Hitachi Metals Corporation's invention patent CN101796207A discloses an amorphous alloy thin tape, a nanocrystalline soft magnetic alloy, and a magnetic core, composed of an Fe-M-Si-B-Cu nanocrystalline alloy. This series of nanocrystalline alloy tapes achieves a permeability exceeding 129,000 at 1kHz, but its permeability at 100kHz is less than 20,000. In summary, the pressure band is biased towards low-frequency applications.

[0004] The characteristic of gravity-prepared nanocrystalline ribbons is their thinness, typically less than 20 μm. These ribbons are characterized by low-frequency performance: permeability <100,000 at 1 kHz, <80,000 at 10 kHz, and <30,000 at 100 kHz. The overall reduction in performance attenuation is due to the low 1 kHz performance, which fails to meet the high-performance requirements at low frequencies. Chinese patent CN108559926A discloses an iron-based amorphous ribbon and its preparation method, as well as a method for preparing high-frequency, high-permeability nanocrystalline alloys. This series of nanocrystalline alloy ribbons can achieve an effective permeability of over 80,000 at 10 kHz and 30,000 at 100 kHz without vacuum transverse magnetic field annealing. In summary, gravity-prepared ribbons are primarily suited for high-frequency applications.

[0005] Based on the performance characteristics of the two types of strips mentioned above, current strips cannot achieve a balance between low, medium, and high frequency performance, nor can they guarantee a reduction in the dispersion of low, medium, and high frequency performance. This limits the application of nanocrystalline soft magnetic alloy strips as common-mode inductor cores.

[0006] In view of this, it is necessary to provide an improved amorphous and nanocrystalline soft magnetic alloy strip and core to solve the above problems. Summary of the Invention

[0007] The purpose of this invention is to provide an amorphous and nanocrystalline soft magnetic alloy strip and core, which significantly improves the permeability at low, medium and high frequencies by controlling the element composition ratio, while reducing the dispersion of permeability at low, medium and high frequencies, so as to meet the application requirements of common mode inductors.

[0008] To achieve the above objectives, the present invention provides an amorphous alloy thin strip, the elemental composition of which includes: Fe f Si a B b Nb c Cu d Ni e And unavoidable impurities, where f, a, b, c, d, and e represent the atomic percentages of the corresponding elements, and satisfy f+a+b+c+d+e=100, 14≤a≤17, 7.5≤b≤9, a+b≥21.5, and 0.5≤e≤3. This invention, by controlling the content of the metalloid elements Si and B, and simultaneously adding Ni, provides favorable conditions for the subsequent transformation of amorphous alloy strips into nanocrystalline materials, and can be used to prepare amorphous nanocrystalline soft magnetic alloy strips with high magnetic permeability and low dispersion.

[0009] Furthermore, a / a+b≥65%; and / or, 15≤a+e≤19.

[0010] Si (silicon) can improve the fluidity of alloys and increase the disorder of atomic arrangement within the alloy, thereby enhancing the alloy's amorphous forming ability and formability, and reducing the difficulty of material preparation. During annealing and crystallization treatment, it can suppress the precipitation of Fe and B compounds in the crystallized nanocrystalline structure, thus stabilizing the nanocrystalline structure. Furthermore, as a metalloid element, Si can effectively improve magnetic permeability: Si is an important element for improving amorphous forming ability and can also improve the stability of secondary phases, thereby increasing magnetic permeability.

[0011] Boron (B) is beneficial for the formation of amorphous alloy ribbons. Insufficient boron content hinders the formation of fully amorphous alloys, while excessive boron content reduces the alloy's saturation magnetic induction and decreases its amorphous formation capability. As a metalloid, boron also promotes permeability, but its effect is less pronounced than that of silicon (Si). Therefore, this invention focuses on controlling the Si / Si+B ratio to ensure both amorphous formation capability and effective permeability.

[0012] Ni plays an important role in improving the performance of this invention. Ni can improve the toughness of the alloy, thereby ensuring that the gravity belt can be used to prepare nanocrystalline ribbons with a thickness of 18-22 μm.

[0013] Furthermore, 2.0 ≤ c ≤ 4.0; and / or, 0.9 ≤ d ≤ 1.2.

[0014] Large atoms such as Nb can form strong interatomic bonds with main element atoms such as Fe, Si, and B. Since the diffusion of large atoms is difficult, adding an appropriate amount can improve the thermal stability of the alloy, inhibit the growth of nanocrystals, and also improve the amorphous formation ability.

[0015] Cu, as an essential element, is beneficial for the formation of nanocrystalline structures during the annealing and crystallization treatment of amorphous alloy strips. However, a Cu content below 0.8 at% is detrimental to nanocrystalline formation. A Cu content above 1.4 at% will cause inhomogeneity of the amorphous phase, hindering the formation of a uniform nanocrystalline structure and leading to a decrease in soft magnetic properties. Considering the embrittlement of nanocrystalline alloys, the Cu content needs to be controlled below 1.3 at%. Therefore, the preferred control range for Cu in this invention is 0.9-1.2 at%.

[0016] Furthermore, 72≤f≤82; preferably, 76≤f≤81. Fe is an essential magnetic element and is key to ensuring high saturation magnetic induction intensity. However, excessive Fe content will reduce the amorphous forming ability of the alloy, causing coarse grains to precipitate during the preparation of amorphous alloy ribbons, thereby deteriorating the soft magnetic properties.

[0017] Furthermore, the amorphous alloy strip has a thickness of 18-22 μm, preferably 20-22 μm.

[0018] To achieve the above objectives, this invention also provides a method for preparing amorphous nanocrystalline soft magnetic alloys, comprising annealing the amorphous alloy strips described in any of the above-mentioned methods to form nanocrystals. This invention modifies the amorphous matrix and nanocrystalline precursor by controlling the content of the metalloid elements Si and B through compositional design. Simultaneously, the addition of Ni element improves toughness, ensuring that the gravity band can produce nanocrystalline strips with a thickness of 18-22 μm; it also controls grain size, promoting the precipitation of more Cu clusters and refining the grains. Furthermore, Ni is a magnetic field-sensitive element, which can control the magnetization stage during heat treatment, thus achieving performance across low, medium, and high frequencies.

[0019] Furthermore, the final annealing temperature is 520-550℃, and the holding time is 60-120 minutes; after the holding time, magnetization is performed during the cooling process. The purpose of annealing is to transform the amorphous alloy ribbon into a nanocrystalline structure. Annealing typically employs segmented heating and holding processes, with the maximum heating temperature not exceeding 550℃. For example, first heat to 400℃-420℃ and hold for 60-100 minutes; then heat to 520-550℃ and hold for 60-120 minutes. Magnetization is usually performed when cooling to between 400℃-500℃. The annealing process is typically carried out in a transverse magnetic furnace.

[0020] Furthermore, this invention also provides an amorphous nanocrystalline soft magnetic alloy, prepared by the above method. The grain size of the nanocrystals is less than or equal to 12 nm, preferably 6-10 nm. This invention, through optimization of the elemental composition ratio, can control the formation process of the nanocrystals, thereby significantly reducing the grain size. The smaller grain size results in a substantial improvement in not only magnetic permeability but also other magnetic properties. The prepared tape thickness is >20 μm, and the tape exhibits low loss (Ps < 8 W / kg) at 0.5 T-20 kHz and low coercivity (Hc < 1 A / m).

[0021] In some specific embodiments, the raw materials are weighed according to their mass ratio and then sequentially added to a medium-frequency induction heating furnace for melting. Argon gas is introduced as a protective gas during the melting process, and the molten steel is calmed for 30 minutes after melting to ensure uniform composition and no segregation. Amorphous alloy strips are prepared using the copper roller rapid quenching method: the molten steel is poured at 1400℃-1500℃, and amorphous nanocrystalline strips are obtained through copper roller rapid quenching. The amorphous nanocrystalline strips are cut into 10mm wide strips and then wound into rings using a winding device; subsequently, they are annealed in a transverse magnetic furnace, and after holding at that temperature, magnetization is performed during the cooling process to obtain an amorphous nanocrystalline soft magnetic alloy.

[0022] The amorphous nanocrystalline soft magnetic alloy formed by this invention can achieve a permeability of over 130,000 at a frequency of 1 kHz, over 110,000 at a frequency of 10 kHz, and over 30,000 at a frequency of 100 kHz.

[0023] To achieve the above objectives, the present invention also provides a magnetic core comprising the amorphous nanocrystalline soft magnetic alloy described in any of the preceding claims. Specifically, the amorphous nanocrystalline soft magnetic alloy strip is wound into a magnetic ring, for example, the strip width is 10 mm, the outer diameter of the magnetic ring is 30 mm, and the inner diameter is 20 mm.

[0024] The beneficial effects of this invention are as follows:

[0025] 1. The amorphous alloy thin strip provided by the present invention improves the amorphous forming ability and molding ability of the alloy by controlling the content of metal-like elements Si and B, and adding Ni element, thereby reducing the difficulty of material preparation and providing conditions for preparing amorphous strips with a thickness of 18-22μm. At the same time, it helps to form small-diameter nanocrystals. Therefore, it can be used to prepare amorphous nanocrystalline soft magnetic alloys with high magnetic permeability and low frequency dispersion.

[0026] 2. The amorphous nanocrystalline soft magnetic alloy provided by this invention, by strictly controlling the elemental composition and content, adding Ni element to improve toughness, and regulating the grain size, can achieve a permeability of over 130,000 at 1kHz, over 110,000 at 10kHz, and over 30,000 at 100kHz, thus taking into account low, medium and high frequency performance, which is convenient for application in various fields. Attached Figure Description

[0027] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0028] Figure 1 The frequency permeability curves are for Example 2 and Comparative Example 2.

[0029] Figure 2 This is a transmission electron microscope (TEM) image of Example 2.

[0030] Figure 3 This is the transmission electron microscope (TEM) image of Comparative Example 2. Detailed Implementation

[0031] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention are described clearly and completely below. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0032] The following preparation method is based on Fe. f Si a B b Nb c Cu d Ni e The invention details an amorphous or nanocrystalline soft magnetic alloy core and studies its properties. The specifics are as follows:

[0033] Smelting of the master alloy: according to Fe f Si a B b Nb c Cu d Ni e Raw materials are selected; where a, b, c, d, and e represent the atomic percentages of the corresponding components; preferably, 14 ≤ a ≤ 17, 7.5 ≤ b ≤ 9, 2.0 ≤ c ≤ 4.0, 0.9 ≤ d ≤ 1.2, 0.5 ≤ e ≤ 3, a + b + c + d + e = 100, while a + b ≥ 21.5, and a / a + b ≥ 65%, 14.5 ≤ a + e ≤ 20. The industrial raw materials required for the master alloy are pure Fe, pure Cu, elemental Si, pure Ni, and Fe-B and Fe-Nb alloys. The purity of the raw materials is shown in Table 1.

[0034] Table 1. Raw Materials and Their Purity

[0035] purity% 99.95 99.99 99.6 99.95 17.94 56.32

[0036] After weighing each raw material according to its mass ratio, they are sequentially added to a medium-frequency induction heating furnace for melting. Argon gas is introduced as a protective gas during the melting process. After melting, the molten steel is calmed for 30 minutes to ensure uniform composition and no segregation. Amorphous alloy thin strips are prepared using the copper roller rapid quenching method: The molten steel is poured at 1400℃-1500℃, and amorphous nanocrystalline strips are obtained through copper roller rapid quenching. The obtained nanocrystalline strips are cut according to the size requirements of common-mode inductors. This invention uses a 30×20×10 nanocrystalline magnetic core for evaluation. The nanocrystalline strips are cut into 10mm wide strips and then wound into rings using a winding device.

[0037] The annealing heat treatment process is carried out in a horizontal magnetic furnace, using a conventional heat treatment control process, which is controlled in stages. The final heat treatment temperature is 520-550℃, and a certain holding time is performed, which is generally 60-120 minutes. After the holding time is completed, magnetization is performed during the cooling process to obtain an amorphous nanocrystalline soft magnetic alloy core.

[0038] Performance evaluation and analysis after heat treatment. The performance evaluation method is as follows: 1) Determination of saturation magnetic induction intensity and coercivity. The saturation magnetization intensity Bs and coercivity of the annealed alloy strip are measured by a vibrating sample magnetometer (VSM) and a soft magnetic DC tester. The equipment is based on the principle of electromagnetic induction to obtain the curve relationship between the sample magnetic moment and the external magnetic field. The range of the test magnetic field is -12500 to 12500 Oe. Before the test, the equipment is calibrated using a prepared Ni standard. Then, the magnetic sample to be tested is crushed, weighed to about 0.032g, wrapped tightly with tin foil, and placed in a copper mold for measurement.

[0039] 2) Measurement of inductance and permeability: The permeability of the nanocrystalline magnetic core after magnetic field heat treatment was measured with frequency using an impedance analyzer, with a focus on the inductance and permeability from 1kHz to 10kHz to 100kHz.

[0040] 3) Measurement of power loss: The BH tester is used to measure the power loss. By setting the sample parameters (effective magnetic circuit length, effective cross-sectional area, number of windings, etc.) and test conditions (test frequency, magnetic field strength, maximum magnetic flux density, maximum induced voltage, etc.), the BH curve is output and various magnetic characteristic parameters are measured. The power loss (Ps) is of particular interest.

[0041] The analysis and testing are as follows: TEM (Transmission Electron Microscopy) analysis: ① The sample thickness observed under TEM should be between 50-200 nm. The nanocrystalline ribbon is cut into 1×1 cm samples. ② Pre-thinning of sample sheets: Chemical thinning method involves placing the cut metal sheet in a prepared chemical reagent to corrode its surface, necessitating thinning. ③ Final thinning: Currently, the most efficient and simplest method is the dual-jet electropolishing method. The pre-thinned sample is cut into 3 mm diameter discs and placed in a sample holder. During thinning, there is an electrolyte nozzle at the center of each of the two surfaces of the sample. Thin film samples prepared in this way have a fairly large thin area near the central hole, which can be penetrated by the electron beam. The periphery of the 3 mm diameter disc acts like a thick rigid support. Since the diameter of the TEM sample holder is also 3 mm, the prepared sample can be directly loaded into the TEM for observation and analysis.

[0042] Examples 1-4 and Comparative Examples 1-6

[0043] Verify the effects and control range of Si, B, and Si+B elements on performance.

[0044] According to the elemental composition listed in Table 2, the raw materials were weighed according to their mass ratios and then sequentially added to a medium-frequency induction heating furnace for melting. Argon gas was used as a protective gas during the melting process. After melting, the mixture was allowed to settle for 30 minutes to ensure uniform steel composition without segregation. The molten steel was then poured at 1400℃-1500℃ and amorphous nanocrystalline strips were obtained through a copper roller rapid quenching method. The strips were then gripped using a specific gripping device and slit. After winding, the strips underwent annealing and magnetization treatment in a transverse magnetic furnace.

[0045] This embodiment primarily verifies the effects of Si and B elements on performance. Si, as a metalloid element, can effectively improve the trend depth and resistivity, thereby increasing magnetic permeability. Simultaneously, Si is an important element for enhancing amorphous formation capability. B, also a metalloid element, can improve magnetic permeability and exhibits outstanding stability in secondary phases. Both are crucial elements for improving magnetic permeability; therefore, this embodiment focuses on exploring their influence on magnetic permeability.

[0046] Table 2. Elemental composition, thickness, and grain size of Examples 1-4 and Comparative Examples 1-6

[0047]

[0048] Table 3 Performance test results of Examples 1-4 and Comparative Examples 1-6

[0049]

[0050]

[0051] As shown in Tables 2 and 3, when the Si content is below 14%, the amorphous forming ability decreases, and the fabricable thickness of the strip decreases. Although the overall Si+B content increases, the Fe content decreases. The decrease in Fe content affects the toughness of the fabricated strip, leading to a reduction in fabricated thickness. In Comparative Examples 3 and 5, although the Fe content is relatively high, the low Si+B content results in poor amorphous forming ability, and the fabricated thickness is also low.

[0052] Si has a significant impact on magnetic permeability; decreasing Si content leads to a decrease in permeability at both high and low frequencies. Furthermore, from... Figure 2 and 3 It can be seen that the grain size of Comparative Example 2 is larger than that of Example 2, which is partly why the magnetic permeability is reduced. From Figure 1It can be seen that the magnetic permeability of Example 2 is better than that of Comparative Example 2. Similarly, the trend of B content variation is as follows: when the B content decreases, it has a greater impact on the amorphous forming ability, resulting in a decrease in the thickness of the prepared strip and a reduction in performance. When the B content increases to greater than 9%, the Fe content decreases accordingly, making it impossible to prepare strips with a thickness greater than 20 μm, which has a significant impact on magnetic permeability. The changes in Ps and Hc are mainly related to the grain size. The decrease in Fe content and the increase in grain size brought about by high Si and B content are the main reasons for the increase in Ps and Hc. Therefore, the Si content in this invention is between 14-17%; the B content is selected to be between 7.5-9%, and Si+B > 21.5%.

[0053] Examples 5-8 and Comparative Examples 7-9

[0054] Verify the impact of Si / Si+B on performance and its control range.

[0055] The same preparation method as in Example 1 was used to prepare the magnetic core according to the elemental composition shown in Table 4, and the performance was tested.

[0056] Table 4. Elemental composition, thickness, and grain size of Examples 5-8 and Comparative Examples 7-9

[0057]

[0058]

[0059] Table 5 Performance test results of Examples 5-8 and Comparative Examples 7-9

[0060]

[0061] As shown in Tables 4 and 5, under the condition that Si and B are within the required ranges, the proportion of Si in the metalloid elements has little effect on the thickness. The thickness of the basic prepared strip is above 19 μm, which is a condition for ensuring low-frequency performance, but it has a significant impact on magnetic properties. When the proportion of Si atoms is greater than 65%, the Si precipitated during crystallization is smaller, the number of nucleation sites is reduced, resulting in a smaller grain size, and the corresponding loss power and coercivity are relatively reduced, while the permeability is increased. As the proportion of B increases, the proportion of Si decreases, the grain size increases, and the magnetic properties are relatively reduced. Therefore, while ensuring that Si and B are within the control range, the focus is on controlling the proportion of Si in the metalloid. In this invention, the proportion of Si is controlled to be greater than or equal to 65%.

[0062] Examples 9-12 and Comparative Examples 10-13

[0063] Verify the effect of Ni on performance and its control range.

[0064] The same preparation method as in Example 1 was used to prepare the magnetic core according to the elemental composition shown in Table 6, and the performance was tested.

[0065] This embodiment mainly verifies the role of Ni: first, it improves toughness, ensuring that the gravity band can be used to prepare nanocrystalline ribbons with a thickness of 20-22 μm; second, it controls the grain size, promotes the precipitation of more Cu clusters, and refines the grains; and third, Ni is a magnetic field-sensitive element that controls the magnetic segment of heat treatment, ensuring low-, medium-, and high-frequency performance.

[0066] Table 6. Elemental composition, thickness, and grain size of Examples 9-12 and Comparative Examples 10-13

[0067]

[0068] Table 7 Performance test results of Examples 9-12 and Comparative Examples 10-13

[0069]

[0070] As shown in Tables 6 and 7, the strip thickness increases significantly with increasing Ni content, indicating a strong promoting effect on toughness. However, as the Ni content further increases, the effect of increasing toughness (i.e., increasing strip thickness) weakens. Above 3%, the toughening effect is comparable, demonstrating Ni's role in increasing thickness. With increasing Ni content, the grain size decreases, indicating Ni can refine the grains. When the Ni content increases from 0.5% to 3%, the grain size gradually decreases from 14nm to approximately 8nm. The addition of Ni promotes the precipitation of more Cu clusters, thus refining the grains. This leads to increased permeability, reduced loss, and decreased coercivity. This is Ni's role in refining grains and improving magnetic properties. A third effect of Ni content is its sensitivity to magnetic fields during heat treatment and transverse magnetization. When the Ni content increases to a certain range, the sensitivity increases, resulting in decreased low-frequency permeability and correspondingly decreased high-frequency permeability. Therefore, an upper limit must be controlled for the Ni content. The sum of Si and Ni is used to better control the effect of Si's magnetic permeability and magnetic susceptibility. When Si + Ni is low, it has no toughening effect; when Si + Ni is high, magnetic field susceptibility increases, and magnetic permeability decreases accordingly. Therefore, the final range of Ni determined in this invention is 0.5-3 at%, and the range of Si + Ni is 14.5-20 at%.

[0071] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. An amorphous alloy thin strip, characterized in that, Its elemental composition includes: Fe f Si a B b Nb c Cu d Ni e Where f, a, b, c, d, and e represent the atomic percentages of the corresponding elements, and satisfy f+a+b+c+d+e=100, 14≤a≤17, 7.5≤b≤9, a+b≥21.5, 0.5≤e≤3; a / a+b≥65%; 15≤a+e≤19; 2.0≤c≤4.0; 0.9≤d≤1.2; the amorphous alloy strip has a thickness of 18-22μm.

2. The amorphous alloy thin strip according to claim 1, characterized in that, 72≤f≤82。 3. The amorphous alloy thin strip according to claim 2, characterized in that, The value is 76≤f≤81.

4. The amorphous alloy thin strip according to claim 1, characterized in that, The amorphous alloy strip is an amorphous alloy strip with a thickness of 20-22 μm.

5. A method for preparing an amorphous nanocrystalline soft magnetic alloy, characterized in that, The nanocrystals are obtained by annealing the amorphous alloy thin strip as described in any one of claims 1-4.

6. The method for preparing amorphous nanocrystalline soft magnetic alloy according to claim 5, characterized in that, The annealing process includes holding the amorphous alloy strip at 520-550℃ for 60-120 minutes; after the holding period, a magnetization process is performed during the cooling process.

7. An amorphous nanocrystalline soft magnetic alloy, characterized in that, It is prepared using the preparation method described in claim 5 or 6.

8. The amorphous nanocrystalline soft magnetic alloy according to claim 7, characterized in that, The grain size of the nanocrystals is less than or equal to 12 nm.

9. The amorphous nanocrystalline soft magnetic alloy according to claim 8, characterized in that, The nanocrystals have a grain size of 6-10 nm.

10. A magnetic core, characterized in that, This includes the amorphous nanocrystalline soft magnetic alloy prepared by the preparation method described in claim 5 or 6, or the amorphous nanocrystalline soft magnetic alloy described in any one of claims 7-9.

Images