All-metallic iron-based nanocrystalline soft magnetic alloy, preparation method thereof and magnetic core

Abstract

The application provides a full-metal iron-based nanocrystalline soft magnetic alloy, which is processed by using full-metal raw materials and does not add non-metal elements; has an Fe-Co-M-N-Cu nanocrystalline alloy system, wherein M=Zr, Hf, Nb; N=Li, Be; the Fe-M-N-Cu system contains 85-90% of Fe. By using the technical scheme, the full-metal iron-based nanocrystalline soft magnetic alloy material is provided, which is a full-metal high-iron-content Fe-Co-M-N-Cu nanocrystalline alloy material, the structure of which comprises an amorphous matrix and nanocrystalline grains, the nanocrystalline grain phase is a body-centered cubic alpha-Fe(Co), and the average grain size is less than 12nm; the iron content is up to 90% and the material can also have high thermal stability and magnetic induction performance.

Description

Technical Field

[0001] This invention relates to the field of iron-based nanocrystalline soft magnetic alloy materials, specifically to an all-metal iron-based nanocrystalline soft magnetic alloy, its preparation method, and magnetic core. Background Technology

[0002] With the development of power systems and electronic communication devices towards higher frequencies and lighter weights, the requirements for the soft magnetic properties of the soft magnetic materials used in them are becoming increasingly stringent. Iron-based nanocrystalline alloys possess excellent soft magnetic properties such as high saturation magnetic induction, high permeability, low iron loss, and low coercivity, along with advantages such as low cost and good energy-saving effects. They are widely used in power electronic devices such as high-frequency switching power supply transformers, high- and medium-frequency high-power transformers, pulse transformers, electronic transformers, inverter welding machine transformers, and distribution transformers, which helps promote the energy-saving, environmentally friendly, miniaturized, and lightweight development of products.

[0003] Iron-based nanocrystalline alloys consist of an amorphous matrix and nanocrystalline grains, obtained through heat treatment of amorphous alloys. Since 1988, when Yoshizawa et al. of Hitachi Metals Corporation in Japan discovered the Fe-Si-B-Nb-Cu nanocrystalline system, it has been widely used due to its high permeability and low coercivity. This discovery also sparked a research boom in iron-based nanocrystalline soft magnetic alloys both domestically and internationally. After decades of research, current nanocrystalline soft magnetic alloys mainly include four systems: FeSiBMCu (M = Nb, Ta, W, Mo, etc.) finemet alloys, FeMB(Cu) (M = Zr, Hf, Nb, etc.) nanoperm alloys, (Fe,Co)MBCu (M = Zr, Hf, Nb, etc.) Hitperm alloys, and FeSiBPCu nanomet alloys. Among these, while finemet alloys possess excellent soft magnetic properties, their typical Fe content is low. 73.6 Nb3Si 13.5 The saturation magnetic induction of B9Cu1 is only 1.24, which limits its application in power electronic devices that are trending towards miniaturization. While Nanoperm and Hitperm alloys possess high saturation magnetic induction and near-zero magnetostriction coefficients, the presence of large amounts of easily oxidized noble metals such as Zr and Hf, and the high Co content in Hitperm alloys, increases production costs and complicates the manufacturing process, hindering their widespread application. In contrast, the high-iron Fe-Si-BP-Cu alloy system boasts extremely high saturation magnetic induction, reaching 1.9T, and has broad application prospects. However, the stringent requirements for strip fabrication and the complex rapid-heating heat treatment processes limit its widespread use.

[0004] Furthermore, iron-based nanocrystalline soft magnetic alloys are ultimately used in power electronic devices in the form of iron cores prepared by winding strips into rings and undergoing heat treatment. Therefore, in actual production, the heat treatment process for large quantities of nanocrystalline iron cores often results in uneven heating and insufficient and uneven nanocrystal precipitation, leading to low saturation magnetic induction and poor soft magnetic properties. This results in poor quality stability of the produced nanocrystalline iron cores, severely restricting the widespread application of iron-based nanocrystalline soft magnetic alloys, especially the production and development of soft magnetic alloys with high iron content. Therefore, researching and developing an iron-based nanocrystalline soft magnetic alloy with excellent comprehensive soft magnetic properties, high thermal stability, and a wide optimal heat treatment temperature and time range has become a key research focus and hot topic in both the market and actual production.

[0005] Chinese invention patent CN101796207A (Hitachi Metals, Ltd.) discloses an amorphous alloy strip, a nanocrystalline soft magnetic alloy, and a magnetic core, belonging to the FeSiBMCu nanocrystalline alloy system. This nanocrystalline alloy exhibits high permeability and low coercivity. However, the saturation magnetic induction intensity of the standard composition of this alloy is only 1.6-1.65T, which needs further improvement. Although the technical solution of this invention improves the soft magnetic properties of the nanocrystalline alloy to some extent through composition adjustment and heat treatment process optimization, it still has drawbacks such as low saturation magnetic induction intensity, low permeability under high application fields, and poor high-temperature thermal stability. Chinese invention patent CN112267057A discloses a soft magnetic high-entropy alloy, which uses an all-metal system to prepare an all-metal alloy with soft magnetic properties. However, its iron content is 10-30%, requiring the addition of large proportions of Ni, Co, and Cu, making large-scale promotion and application extremely difficult from an economic cost perspective.

[0006] In summary, developing an iron-based nanocrystalline soft magnetic alloy material that combines high saturation magnetic induction, high-temperature thermal stability, and high magnetic permeability under high-field applications is of great significance for promoting the development of new green and energy-saving power electronic devices and the widespread application of iron-based nanocrystalline soft magnetic alloys. Summary of the Invention

[0007] To address the technical problems existing in the prior art, this invention provides an all-metal iron-based nanocrystalline soft magnetic alloy, its preparation method, and magnetic core. The all-metal iron-based nanocrystalline soft magnetic alloy does not contain any non-metallic elements and has high thermal stability, high power, large capacity, high frequency, and high magnetic induction intensity. It also has high saturation magnetic induction intensity, high temperature thermal stability, and high permeability under high field applications.

[0008] To achieve the above objectives, the present invention provides the following technical solution: an all-metal iron-based nanocrystalline soft magnetic alloy, characterized in that the all-metal iron-based nanocrystalline soft magnetic alloy is made from all-metal raw materials without the addition of non-metallic elements; it has an Fe-Co-MN-Cu nanoalloy system, wherein M = Zr, Hf, Nb; N = Li, Be; and the Fe content is 85-90%.

[0009] It is generally believed that Fe, as a magnetic element, is key to ensuring high saturation magnetic induction, but a high Fe content leads to a decrease in amorphous formation capability. Therefore, the Fe content typically selected in existing technologies is no higher than 85%. This invention provides an all-metallic iron-based nanocrystalline soft magnetic alloy that maximizes the Fe content to as high as possible, reaching up to 90%, far exceeding the iron content in existing alloys. Meanwhile, Zr and Be are indispensable elements for improving the alloy's amorphous formation capability, while Cu provides heterogeneous nucleation sites for nanocrystalline nucleation and is an important element for increasing the amount of nanocrystalline precipitation. The addition of Be significantly improves the bending toughness of the alloy strip, which is of great significance for subsequent winding and forming of the alloy strip. Regarding soft magnetic properties, the addition of Be significantly reduces the magnetostriction coefficient of the alloy strip, optimizing the alloy's soft magnetic properties. As a superior technical solution, Co is introduced into the aforementioned alloy system. Co, as an iron-group transition element, can improve the mixing enthalpy and atomic mismatch ratio among the alloying elements, enhancing amorphous formation capability, while also inhibiting nanocrystal growth. Simultaneously, the magnetic interaction coupling between Fe and Co elements can increase the alloy's saturation magnetic induction, improving soft magnetic properties. Therefore, it is necessary to find a balance range so that the constituent alloying elements can simultaneously increase amorphous formation capability, optimize soft magnetic properties, and improve heat treatment range and high-frequency characteristics. Based on the above theoretical analysis, this invention further optimizes the composition of the all-metal high-iron nanocrystalline soft magnetic alloy.

[0010] In a preferred embodiment, the molecular formula of the all-metal iron-based nanocrystalline soft magnetic alloy is: Fe a Zr b Be c Co d Cu e Wherein, a, b, c, d and e represent the atomic percentage content of each alloying element in the iron-based nanocrystalline soft magnetic alloy, and satisfy the following conditions: 85≤a≤90; 7b≤9; 0c≤2; 0d≤5; 0.7≤e≤2; a+b+c+d+e=100; more preferably, 0.7≤e≤1.

[0011] As a preferred embodiment, the purity of the raw material for the all-metal iron-based nanocrystalline soft magnetic alloy is ≥99.9%.

[0012] In a preferred embodiment, the all-metallic iron-based nanocrystalline soft magnetic alloy has a body-centered cubic α-Fe(Co) nanocrystal structure embedded on an amorphous substrate. More preferably, the average grain size of the α-Fe(Co) nanocrystals is 10–12 nm.

[0013] In a preferred embodiment, the coercivity of the all-metal iron-based nanocrystalline soft magnet remains at 10 A / m after heat treatment at 580–620°C for 30–60 minutes.

[0014] As a preferred embodiment, the saturation magnetic induction intensity of the nanocrystalline soft magnetic alloy after crystallization heat treatment is 1.7~1.8T; the maximum permeability at 1kHz and 80A / m in the application field is ≥25000; and the permeability at 10kHz is ≥25000.

[0015] To achieve another objective, the present invention also provides a method for preparing the above-mentioned all-metal iron-based nanocrystalline soft magnetic alloy, comprising the following steps:

[0016] (1) Weigh each alloy raw material and mix them;

[0017] (2) Preparation of master alloy ingot: The alloy raw material is placed in an electric arc melting device and melted under an inert atmosphere at a melting temperature of 1300-1800℃; the melting is repeated 4-5 times to obtain the master alloy ingot.

[0018] (3) Preparation of rapid quenching strip: The master alloy ingot obtained in step (2) is crushed and then placed into a quartz tube with a nozzle at the bottom. The strip is processed by a single-roller rapid cooling and spinning process to prepare amorphous alloy rapid quenching strip.

[0019] (4) Crystallization heat treatment: The amorphous alloy obtained in step (3) is placed in a heat treatment furnace and heated at a uniform rate to 480-640°C. After holding at the temperature for 10-60 minutes, it is taken out and quenched to room temperature to obtain the all-metal iron-based nanocrystalline soft magnetic alloy.

[0020] In a preferred embodiment, in step (3), the rapidly quenched amorphous alloy strip is strip-shaped, with a width of 1-2 mm and a thickness of 20-25 μm. More preferably, the rapidly quenched strip has a width of 1.5-2 mm and a thickness of 23-25 ​​μm.

[0021] In a preferred embodiment, step (3) involves spinning the belt at a speed of 30-40 m / s in an argon atmosphere.

[0022] In a preferred embodiment, in step (4), the rate of uniform heating is 1 to 10 °C / s.

[0023] To address the technical problems of existing technologies, this invention provides a metal-free (Si, B, P, C), high-Fe-content all-metal iron-based nanocrystalline soft magnetic alloy with the structural formula Fe-Co-MN-Cu (M = Zr, Hf, Nb, etc.; N = Li, Be, etc.) nanocrystalline alloy. This alloy system does not contain (Si, B, P, C) elements, and the Fe content is significantly increased compared to traditional alloys. Generally, high-speed iron alloys deteriorate easily under high-temperature conditions, and the reduced amorphous formation ability leads to a lack of excellent soft magnetic properties. This invention improves the soft magnetic properties by optimizing the elemental ratio of the all-metal iron-based alloy, utilizing the magnetic interaction coupling between Fe and Co elements to increase the alloy's saturation magnetic induction intensity, and simultaneously adding Cu and Be to increase the amount of nanocrystalline precipitation and reduce the magnetostriction coefficient of the alloy strip. This optimizes the alloy's soft magnetic properties, ultimately obtaining an all-metal iron-based nanocrystalline soft magnetic alloy that maintains excellent soft magnetic properties even under high-temperature conditions.

[0024] Therefore, the saturation magnetization of the alloy is effectively improved. At the same time, its excellent high permeability and high frequency stability under high application fields greatly promote the development and research of iron-based nanocrystalline alloys in the fields of energy-saving, environmentally friendly, miniaturized, and lightweight high power density ultra-high frequency high precision power controllers and high frequency transformers for accelerators.

[0025] The all-metal iron-based nanocrystalline soft magnetic alloy provided by the above scheme can be used in various transformers, various reactors and choke coils, noise control components, laser power supplies and accelerators, pulse power magnetic components, communication pulse transformers, various motor cores, various generators, various magnetic sensors, antenna cores, various current sensors, magnetic shielding, etc.

[0026] Technical effects of the present invention:

[0027] 1. The all-metal iron-based nanocrystalline soft magnetic alloy material provided by adopting the technical solution of the present invention is an all-metal high-iron Fe-Co-MN-Cu nanocrystalline alloy material, the structure of which includes an amorphous matrix and nanocrystalline grains. The nanocrystalline grains are body-centered cubic α-Fe(Co) with an average grain size of less than 12nm. The iron content can reach up to 90% while also having high thermal stability and magnetic induction performance.

[0028] 2. The iron-based nanocrystalline soft magnetic alloy material obtained after crystallization heat treatment using the technical solution of this invention has excellent soft magnetic properties. At the same time, it also has the characteristics of high thermal stability, high power, large capacity, high frequency and high magnetic induction intensity. Its saturation magnetic induction intensity is 1.70~1.80T, and its coercivity is ~10A / m. Meanwhile, the maximum permeability at 1kHz and 80A / m in the application field exceeds 25000, and the permeability at 10kHz exceeds 25000, exhibiting extremely high frequency stability.

[0029] 3. The novel all-metal iron-based nanocrystalline soft magnetic alloy material of the present invention, characterized by high thermal stability, high power and large capacity, high frequency and high magnetic induction intensity, has the advantages of excellent comprehensive soft magnetic properties, high permeability and high thermal stability under high field applications, and has good application prospects, such as in the fields of high power and high precision power controllers for accelerators and high frequency transformers.

[0030] 4. By adopting the technical solution of this invention, the soft magnetic alloy with high iron content is improved, which not only has high temperature stability and excellent soft magnetic properties, but also reduces raw material costs, has a simple preparation process, and has broad market application and promotion prospects. Attached Figure Description

[0031] Figure 1 Flowchart of the preparation process of the all-metal iron-based nanocrystalline alloy in Example 1 of this invention.

[0032] Figure 2 The X-ray diffraction patterns are those of the quenched amorphous alloy strips of Examples 1-2 and Comparative Example 1 of this invention.

[0033] Figure 3 The DSC curves are for the quenched amorphous alloy strips of Examples 1-2 and Comparative Example 1 of this invention.

[0034] Figure 4 The coercivity curves of the quenched amorphous alloys of Examples 1-2 and Comparative Example 1 after heat treatment at 480-640℃ for 30 min are shown.

[0035] Figure 5 The coercivity of the quenched amorphous alloys of Examples 1-2 and Comparative Example 1 of the present invention after heat treatment at 600°C for different times.

[0036] Figure 6a The hysteresis loop and saturation magnetic induction intensity of the nanocrystalline alloys obtained after crystallization heat treatment in Examples 1-2 and Comparative Example 1 of this invention.

[0037] Figure 6b for Figure 6a Enlarged image.

[0038] Figure 7The curves showing the change of magnetic permeability with frequency under different field strengths after heat treatment at 520℃ for 30 min under optimal conditions, as shown in Comparative Example 1 of this invention.

[0039] Figure 8 This is a curve showing the change of magnetic permeability with frequency under different field strengths after heat treatment at 600℃ for 30 min in Example 1 of the present invention.

[0040] Figure 9 This is the curve of magnetic permeability versus frequency under different field strengths after heat treatment at 600℃ for 30 min in Example 2 of the present invention.

[0041] Figure 10 The X-ray diffraction patterns of the amorphous alloys of Examples 1-2 and Comparative Example 1 of this invention after heat treatment at 600℃ for 30 min are shown.

[0042] Figure 11a This is a TEM bright-field image of the nanocrystalline alloy after heat treatment at 600℃ for 30 min in Example 1 of the present invention.

[0043] Figure 11b This is a particle size distribution diagram of the nanocrystalline alloy after heat treatment at 600℃ for 30 min in Example 1 of the present invention.

[0044] Figure 12a This is a TEM bright-field image of the nanocrystalline alloy after heat treatment at 600℃ for 30 min in Example 2 of the present invention.

[0045] Figure 12b This is a particle size distribution diagram of the nanocrystalline alloy after heat treatment at 600℃ for 30 min in Example 2 of the present invention. Detailed Implementation

[0046] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention are clearly and completely described. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of the present invention.

[0047] This invention provides an all-metal iron-based nanocrystalline soft magnetic alloy, which is made from all-metal raw materials without the addition of non-metallic elements; it has an Fe-Co-MN-Cu alloy system, wherein M = Zr, Hf, Nb; N = Li, Be; and the iron content is 85-90%.

[0048] In a preferred embodiment, the molecular formula of the above-mentioned nanocrystalline soft magnetic alloy is: Fe a Zr b Be c Cod Cu e Wherein, a, b, c, d and e represent the atomic percentage content of each alloying element in the iron-based nanocrystalline soft magnetic alloy, and satisfy the following conditions: 85≤a≤90; 7b≤9; 0c≤2; 0d≤5; 0.7≤e≤2; a+b+c+d+e=100; more preferably, 0.7≤e≤1.

[0049] In a preferred embodiment, the purity of the raw material for the above-mentioned all-metal iron-based nanocrystalline soft magnetic alloy is ≥99.9%.

[0050] In a preferred embodiment, the all-metal iron-based nanocrystalline soft magnetic alloy has a body-centered cubic α-Fe(Co) nanocrystal structure embedded on an amorphous substrate. More preferably, the average grain size of the α-Fe(Co) nanocrystals is 10–12 nm.

[0051] This invention provides a method for preparing the above-mentioned all-metal iron-based nanocrystalline soft magnetic alloy, the specific steps of which include:

[0052] (1) Weigh each alloy raw material for batching; specifically, according to the molecular formula: FeaZrbBecCodCue, weigh each element for batching, and the subscripts a, b, c, d and e respectively represent the atomic percentage content of each corresponding alloy element, and satisfy the following conditions: 85≤a≤90; 7b≤9; 0c≤2; 0d≤5; 0.7≤e≤2.

[0053] (2) Preparation of master alloy ingot: The alloy raw material from step (1) is placed in an electric arc melting device and melted under an inert atmosphere. The melting temperature is 1300-1800℃. The melting is repeated 4-5 times to obtain the master alloy ingot.

[0054] (3) Preparation of rapid quenching strip: The master alloy ingot obtained in step (2) is crushed and then put into a quartz tube with a nozzle at the bottom. It is then processed by a single-roller rapid cooling and spinning process to prepare amorphous alloy rapid quenching strip.

[0055] (4) Crystallization heat treatment: The amorphous alloy obtained in step (3) is placed in a heat treatment furnace and heated to 480-640°C at a heating rate of 1-10°C / s. After holding at the temperature for 10-60 minutes, it is taken out and quenched to room temperature to obtain an all-metal iron-based nanocrystalline soft magnetic alloy.

[0056] The all-metal iron-based nanocrystalline soft magnetic alloy prepared using the above method has the following properties:

[0057] After heat treatment at 580–620℃ for 30–60 minutes, the coercivity remains at 10 A / m; the saturation magnetic induction of the nanocrystalline soft magnetic alloy obtained after crystallization heat treatment is ≥1.71T; the maximum permeability at 1kHz and 80A / m in the application field is ≥25000; and the permeability at 10kHz is ≥25000.

[0058] The technical solution of the present invention will be further described in detail below through specific embodiments.

[0059] Example 1

[0060] The molecular formula of the all-metallic iron-based nanocrystalline soft magnetic alloy provided in this embodiment is Fe. 90 Zr7Be2Cu1.

[0061] See Figure 1 The specific preparation method is as follows:

[0062] Step 1: Combine raw materials Fe, Zr, Be, and Cu with a purity greater than 99.9% according to the compositional relationship formula Fe 90 Zr7Be2Cu1 is used as an ingredient in the batch.

[0063] Step 2: Place the proportioned raw materials into the electric arc melting furnace and evacuate to a vacuum level below 2.0 × 10⁻⁶. -2 Pa, then argon gas is introduced to a pressure of -0.05 to 0.01 MPa and the two sides are melted 4-5 times to obtain an alloy ingot with uniform composition.

[0064] Step 3: After crushing the alloy ingot obtained in Step 2, it is loaded into a quartz tube with a nozzle at the bottom. The amorphous alloy strip is produced by using a single-roller rapid cooling and spinning process in an argon atmosphere at a speed of 30-40 m / s.

[0065] Step 4: Place the amorphous alloy strip obtained in Step 3 into a quartz tube and evacuate to 5.0 × 10⁻⁶. -3 Pa, place the quartz tube in a heat treatment furnace, raise the temperature to 600°C at a rate of about 2°C / s, hold for 30 minutes, then quickly remove the quartz tube and quench it in water to room temperature to obtain the nanocrystalline alloy material.

[0066] The microstructure of the quenched alloy strips prepared in step 3 and the alloy strips after heat treatment in step 4 were characterized using a D8 Advance polycrystalline X-ray diffractometer. The results are as follows: Figure 2 and Figure 10 As shown.

[0067] See Figure 2 The spectrum of Example 1 shows that the alloy strip prepared in step 3 has a broadened diffuse diffraction peak, indicating that the alloy strip has an amorphous structure.

[0068] See Figure 10 In the spectrum of Example 1, crystallization peaks appeared in the alloy strips after holding at 600℃ for 30 min. Analysis showed that the crystallized phase was body-centered cubic Fe, i.e., α-Fe. The grain size was estimated to be around 12 nm using the Scherrer formula.

[0069] Furthermore, Figure 11a and Figure 11b The images shown are the TEM bright-field image and grain size distribution of the alloy strips after heat treatment in step 4 under optimal conditions. The microstructure of the samples was measured using a Tecnai F20 transmission electron microscope. It can be seen that the alloy strip structure after crystallization heat treatment consists of an amorphous phase and nanocrystals distributed in the amorphous matrix. The size of these nanocrystals is approximately 10–12 nm, which is consistent with the X-ray diffraction analysis results. The uniform distribution of refined grains is an intrinsic factor contributing to the excellent soft magnetic properties of the alloy prepared in Example 1.

[0070] Figure 3 The figure shows the DSC curve of the alloy strip prepared in step 3. The DSC curve was measured using a NETZSCH DSC404C differential scanning calorimeter at a heating rate of 0.67℃ / s. It can be seen that the alloy strip exhibits a significant exothermic enthalpy change, indicating that the prepared alloy possesses the characteristics of an amorphous alloy.

[0071] Figure 4 and Figure 5 The figure shows the coercivity of the alloy strip after heat treatment in step 4, as a function of temperature and time. The coercivity was measured using a DC BH meter (EXPH-100). It can be seen that after holding at 600℃ for 30 minutes, the coercivity remains around 10 A / m within the range of 600–620℃. Furthermore, the coercivity remains relatively low within the range of 20–40 minutes of heat treatment at 600℃, indicating that this alloy possesses high high-temperature thermal stability.

[0072] Figure 6a and Figure 6b The figure shows the hysteresis loop of the alloy strip under optimal conditions after heat treatment in step 4. The hysteresis loop was measured using a vibrating sample magnetometer (VSM, Lakeshore 7410) to test the saturation magnetic induction intensity of the alloy. It can be seen that the saturation magnetic induction intensity of the alloy is 1.71T. The significant improvement in saturation magnetic induction intensity is beneficial to achieving energy saving, environmental protection, miniaturization, and lightweighting of the product.

[0073] Figure 8The figure shows the permeability of the alloy strip under different field strengths under optimal conditions after heat treatment in step 4, measured using an impedance analyzer (Agilent 4294A). As can be seen from the figure, the permeability initially increases and then decreases with increasing applied field. At an applied field of 50 A / m, the optimal permeability at 1 kHz reaches 33,000, and at an applied field of 80 A / m, the permeability at 1 kHz also reaches over 26,000. Furthermore, the permeability at 10 kHz does not show any attenuation under the corresponding applied field, indicating that this alloy possesses high frequency stability and ultra-high permeability. This high permeability and high frequency stability under high applied fields can be applied to high-power-density ultra-high-frequency high-precision power controllers for accelerators, high-frequency transformers, and other technical fields.

[0074] Example 2

[0075] In this embodiment, the molecular formula of the novel all-metallic iron-based nanocrystalline soft magnetic alloy material is Fe. 85 Zr7Be2Co5Cu1.

[0076] The specific preparation method of this iron-based nanocrystalline alloy is as follows:

[0077] Step 1: Combine raw materials Fe, Zr, Be, Co, and Cu with a purity greater than 99.9% according to the compositional relationship formula Fe 85 Zr7Be2Co5Cu1 was used as an ingredient in the formulation.

[0078] Step 2: Place the proportioned raw materials into the electric arc melting furnace and evacuate to a vacuum level below 2.0 × 10⁻⁶. -2 Pa, then argon gas is introduced to a pressure of -0.05 to 0.01 MPa and the two sides are melted 4-5 times to obtain an alloy ingot with uniform composition.

[0079] Step 3: After crushing the alloy ingot obtained in Step 2, it is loaded into a quartz tube with a nozzle at the bottom. The amorphous alloy strip is produced by using a single-roller rapid cooling and spinning process in an argon atmosphere at a speed of 30-40 m / s.

[0080] Step 4: Place the amorphous alloy strip obtained in Step 3 into a quartz tube and evacuate to 5.0 × 10⁻⁶. -3 Pa, place the quartz tube in a heat treatment furnace, raise the temperature to 520-640°C at a heating rate of about 2°C / s, hold for 10-60 minutes, then quickly remove the quartz tube and quench it in water to room temperature to obtain the nanocrystalline alloy material.

[0081] The microstructure of the quenched alloy strips prepared in step 3 and the alloy strips after heat treatment in step 4 were characterized using a D8 Advance polycrystalline X-ray diffractometer. The results are as follows: Figure 2 and Figure 10As shown in the figure, the alloy strip prepared in step 3 has a broadened diffuse diffraction peak, indicating that the alloy strip has an amorphous structure. After holding at 600℃ for 30 min, the alloy strip showed a crystallization peak. Analysis showed that the crystallized phase has a body-centered cubic structure, i.e., α-Fe(Co), and its grain size was estimated to be around 11.5 nm using the Scherrer formula.

[0082] Figure 12a The image shown is a bright-field TEM image of the alloy strip under optimal conditions after heat treatment in step 4. Figure 12b The image shows the particle size distribution of the alloy strips under optimal conditions after heat treatment in step 4. The microstructure of the samples was measured using a Tecnai F20 transmission electron microscope. It can be seen that the alloy strip structure after crystallization heat treatment consists of an amorphous phase and nanocrystals distributed within the amorphous matrix. The size of these nanocrystals is approximately 10–12 nm, which is consistent with the X-ray diffraction analysis results. The addition of Co element, leading to further grain refinement, is an intrinsic factor contributing to the excellent soft magnetic properties of this alloy.

[0083] Figure 3 The figure shows the DSC curve of the alloy strip prepared in step 3. The DSC curve was measured using a NETZSCH DSC404C differential scanning calorimeter at a heating rate of 0.67℃ / s. It can be seen that the alloy strip exhibits a significant exothermic enthalpy change, indicating that the prepared alloy possesses the characteristics of an amorphous alloy.

[0084] Figure 4 and Figure 5 The figure shows the coercivity of the alloy strip after heat treatment in step 4, as a function of temperature and time. The coercivity was measured using a DC BH meter (EXPH-100). It can be seen that after holding at 580–620℃ for 30 min, the coercivity remains around 10 A / m, and after heat treatment at 600℃ for 20–40 min, the coercivity remains relatively low. This indicates that the alloy possesses high high-temperature thermal stability.

[0085] Figure 6 shows the hysteresis loop of the alloy strip under optimal conditions after heat treatment in step 4. The hysteresis loop was measured using a vibrating sample magnetometer (VSM, Lakeshore 7410) to test the saturation magnetic induction intensity of the alloy. It can be seen that the saturation magnetic induction intensity of the alloy is 1.78T. This interaction and coupling effect of Fe and Co elements significantly improves the saturation magnetic induction intensity, which is more conducive to achieving energy saving, environmental protection, miniaturization, and lightweighting of the product.

[0086] Figure 9The figure shows the permeability of the alloy strip under different field strengths under optimal conditions after heat treatment in step 4, measured using an impedance analyzer (Agilent 4294A). As can be seen from the figure, the permeability first increases and then decreases with increasing applied field. At an applied field of 80 A / m, the optimal permeability at 1 kHz reaches 27,000, and at an applied field of 100 A / m, the permeability at 1 kHz also reaches over 25,000. Furthermore, the permeability at 10 kHz does not show any attenuation under the corresponding applied field, indicating that this alloy possesses high frequency stability and ultra-high permeability. This high permeability and high frequency stability under high applied fields can be applied to high-power, high-capacity, ultra-high frequency, high-precision power controllers for accelerators, high-frequency transformers, and other technical fields.

[0087] Comparative Example 1

[0088] This comparative example uses Nanoperm alloy as a reference. The molecular formula of Nanoperm nanocrystalline soft magnetic alloy material is Fe. 90 Zr7B2Cu1.

[0089] The specific preparation method of the iron-based nanocrystalline alloy in this comparative example is as follows:

[0090] Step 1: Combine raw materials Fe, Zr, B, and Cu with a purity greater than 99% according to the compositional relationship formula Fe 90 Zr7B2Cu1 is used as an ingredient.

[0091] Step 2: Place the proportioned raw materials into the electric arc melting furnace and evacuate to a vacuum level below 2.0 × 10⁻⁶. -2 Pa, then argon gas is introduced to a pressure of -0.05 to 0.01 MPa and the two sides are melted 4-5 times to obtain an alloy ingot with uniform composition.

[0092] Step 3: After crushing the alloy ingot obtained in Step 2, it is loaded into a quartz tube with a nozzle at the bottom. The amorphous alloy strip is produced by using a single-roller rapid cooling and spinning process in an argon atmosphere at a speed of 30-40 m / s.

[0093] Step 4: Place the amorphous alloy strip obtained in Step 3 into a quartz tube and evacuate to 5.0 × 10⁻⁶. -3 Pa, place the quartz tube in a heat treatment furnace, raise the temperature to 600℃ at a rate of 2℃ / s, hold for 10-60 minutes, then quickly remove the quartz tube and quench it in water to room temperature to obtain nanocrystalline alloy material.

[0094] Performance characterization:

[0095] The XRD patterns of the quenched amorphous alloy strips obtained in step 3 and the nanocrystalline alloy material after heat treatment in step 4 were measured using a D8 Advance polycrystalline X-ray diffractometer, respectively. The results are as follows: Figure 2 and Figure 10 As shown.

[0096] See Figure 2 and Figure 10 The results show that the alloy strip prepared in step 3 has a broadened diffuse diffraction peak, indicating that the alloy strip has an amorphous structure. After holding at 600℃ for 30 min, the alloy strip showed α-Fe and Fe3Zr crystallization peaks, indicating that the alloy has poor high-temperature thermal stability.

[0097] Its grain size is estimated to be around 18 nm using the Scherrer formula.

[0098] Figure 3 The figure shows the DSC curve of the alloy strip prepared in step 3. The DSC curve was measured using a NETZSCH DSC404C differential scanning calorimeter at a heating rate of 0.67℃ / s. It can be seen that the alloy strip exhibits a significant exothermic enthalpy change, indicating that the prepared alloy possesses the characteristics of an amorphous alloy.

[0099] Figure 4 and Figure 5 The figure shows the coercivity of the alloy strip after heat treatment in step 4 as a function of temperature and time. The coercivity was measured using a DC BH meter (EXPH-100). It can be seen that during the 30-minute holding period, the coercivity remained around 10 A / m within the 520–540℃ range. However, the coercivity deteriorated rapidly above 540℃. During the 600℃ heat treatment for 10–60 minutes, the coercivity was only approximately 10 A / m at 10 minutes. This indicates that compared to Examples 1 and / or 2, this alloy exhibits better high-temperature thermal stability.

[0100] Figure 6a and Figure 6b The image shows the hysteresis loop and magnified view of the alloy strip under optimal conditions after heat treatment in step 4. The hysteresis loop was measured using a vibrating sample magnetometer (VSM, Lakeshore 7410) to test the saturation magnetic induction intensity of the alloy. It can be seen that the saturation magnetic induction intensity of the alloy is 1.61T.

[0101] Figure 7The figure shows the permeability of the alloy strip under different field strengths after heat treatment in step 4, measured using an impedance analyzer (Agilent 4294A). As can be seen from the figure, the permeability first increases and then decreases with increasing applied field. At an applied field of 50 A / m, the optimal permeability at 1 kHz is only 23000, and at 10 kHz it is 22000, indicating that this alloy has relatively high frequency stability. However, the permeability under high applied fields is still relatively low, making it difficult to use in high-power-density, ultra-high-frequency, high-precision power controllers for accelerators, high-frequency transformers, and other technical fields.

[0102] As can be seen from the technical solutions and performance test results of the above embodiments and comparative examples, the all-metal, high-iron-content iron-based nanocrystalline soft magnetic alloy provided in the embodiments can control the iron content at 85-90% without adding non-metals such as Si, B, P, and C, and can improve the saturation magnetization of the soft magnetic alloy. At the same time, it also has excellent high permeability and high frequency stability under high application fields, thereby expanding the application of all-metal, high-iron-content soft magnetic alloys in the fields of miniaturized and lightweight high-power-density ultra-high-frequency high-precision power controllers for accelerators, high-frequency transformers, etc.

[0103] The above are merely preferred embodiments of the present invention and do not limit the scope of protection of the present invention. For those skilled in the art, the present invention can have various modifications and variations. Any changes, modifications, substitutions, integrations, and parameter alterations to these embodiments within the spirit and principles of the present invention, achieved through conventional substitutions or by achieving the same function without departing from the principles and spirit of the present invention, fall within the scope of protection of the present invention.

Claims

1. An all-metallic, iron-based nanocrystalline soft magnetic alloy, characterized in that, The full-metal iron-based nanocrystalline soft magnetic alloy has a molecular formula of Fe a Zr b Be c Co d Cu e ; wherein a, b, c, d and e respectively represent the atomic percentage content of each alloy element in the iron-based nanocrystalline soft magnetic alloy, and the following conditions are met: 85≤a≤90; 7≤b≤9; 0≤c≤2; 0≤d≤5; 0.7≤e≤2; a+b+c+d+e=100.

2. The all-metallic, iron-based nanocrystalline soft magnetic alloy of claim 1, wherein, The full-metal iron-based nanocrystalline soft magnetic alloy has a body-centered cubic structure of a-Fe(Co) nanocrystals and is embedded in an amorphous base.

3. The all-metallic, iron-based nanocrystalline soft magnetic alloy of claim 2, wherein, The average grain size of the a-Fe(Co) nanocrystals is 10-12 nm.

4. The all-metallic, iron-based nanocrystalline soft magnetic alloy of any one of claims 1 to 3, wherein The full-metal iron-based nanocrystalline soft magnetic alloy is prepared by sequentially performing a melting-single-roller rapid quenching process-crystallization heat treatment process.

5. The all-metallic, iron-based nanocrystalline soft magnetic alloy of claim 4, wherein, After the full-metal iron-based nanocrystalline soft magnetic alloy is heat-treated at 580-620 ℃ for 30-60 min, the coercive force is maintained at 10 A / m; after the nanocrystalline soft magnetic alloy is subjected to the crystallization heat treatment, the saturation magnetic induction intensity is 1.7-1.8 T; the maximum permeability under an application field of 80 A / m at 1 kHz is greater than or equal to 25,000; and the permeability at 10 kHz is greater than or equal to 25,000.

6. The all-metallic, iron-based nanocrystalline soft magnetic alloy of any one of claims 1-3, wherein, The purity of the raw material of the full-metal iron-based nanocrystalline soft magnetic alloy is greater than or equal to 99.9%.

7. A method of producing a full-metallic, iron-based nanocrystalline soft magnetic alloy according to any one of claims 1 to 6, characterized in that The method comprises the following steps: (1) weighing each alloy raw material for batching; (2) preparing a master alloy ingot: placing the alloy raw material in an electric arc melting device and melting under the protection of an inert atmosphere, with a melting temperature of 1300-1800 ℃; repeatedly melting 4-5 times to obtain the master alloy ingot; (3) preparing a rapid quenching ribbon: crushing the master alloy ingot prepared in step (2) and loading the crushed master alloy ingot into a quartz tube with a nozzle at the bottom, and then performing a single-roller rapid quenching process to prepare a rapid quenching ribbon of an amorphous alloy; (4) crystallization heat treatment: loading the amorphous alloy prepared in step (3) into a heat treatment furnace, uniformly heating to 480-640 ℃ at a speed, keeping for 10-60 min, taking out, and quenching to room temperature to obtain the full-metal iron-based nanocrystalline soft magnetic alloy.

8. The method of producing an all-metallic, iron-based nanocrystalline soft magnetic alloy according to claim 7, wherein In step (3), the rapid quenching ribbon is in the form of a strip, with a width of 1-2 mm and a thickness of 20-25 μm; the single-roller rapid quenching process comprises quenching at a speed of 30-40 m / s in an argon atmosphere; and / or in step (4), the uniform heating speed is 1-10 ℃ / s.

9. A magnetic core comprising the full-metal iron-based nanocrystalline soft magnetic alloy according to any one of claims 1-6.

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