An amorphous nanocrystalline soft magnetic alloy with high saturation magnetic induction and low coercivity and a preparation method thereof

Abstract

The application belongs to the technical field of amorphous nanocrystalline soft magnetic material and its preparation, and particularly relates to an amorphous nanocrystalline soft magnetic alloy with high saturation magnetic induction and low coercivity and a preparation method thereof. a B b Si c Cu d Q e (M is Fe, or M includes at least one of Co and Ni and Fe, and the atomic percentage content of Fe in M is greater than or equal to 75%; Q is at least one of C, P and Cr). The alloy contains at least one of an alpha-Fe nanophase or a crystal nucleus or a ferromagnetic atomic cluster with a size less than 20 nm in a quenched state. Different from a preparation method of a traditional nanocrystalline soft magnetic alloy, which needs to prepare an amorphous alloy first and then perform crystallization annealing above a first starting crystallization temperature, the amorphous alloy in the application does not need to be crystallized by annealing, but only needs to be stress-relieved annealed (also known as relaxation annealing) at 50-120 DEG C below the first starting crystallization temperature, and the saturation magnetic induction of the alloy can reach 1.71-1.97 T, and the coercivity is as low as 1.0-7.0 A / m. By optimizing the alloy composition ratio and the heat treatment process, the application realizes a good balance between high magnetic induction and low coercivity, and the alloy is suitable for manufacturing high-frequency transformers, inductors and other power electronic devices.

Description

Technical Field

[0001] This invention belongs to the field of amorphous nanocrystalline soft magnetic materials and their preparation technology, and specifically relates to an amorphous nanocrystalline soft magnetic alloy with high saturation magnetic induction intensity and low coercivity and its preparation method. Background Technology

[0002] The main application areas of amorphous and nanocrystalline soft magnetic alloys include power electronics fields such as distribution transformers, power transformers, high-frequency transformers, chokes, pulse transformers, and saturated reactors, as well as electronic information fields such as switching power supplies and interface devices. The saturation magnetic induction and coercivity of iron-based amorphous and nanocrystalline soft magnetic alloys are key factors determining their performance. High saturation magnetic induction means a stronger magnetic flux density can be generated under the same magnetic field, which is crucial for the miniaturization of power electronic devices. For example, in transformers, high saturation magnetic induction can reduce the volume and weight of the core and increase power density. Coercivity, on the other hand, reflects the material's ability to resist changes in magnetic field; low coercivity means the material is more easily magnetized and demagnetized, reducing energy loss. Therefore, the balance between saturation magnetic induction and coercivity has a critical impact on the performance and applications of iron-based amorphous and nanocrystalline soft magnetic alloys.

[0003] Currently, developing amorphous and nanocrystalline soft magnetic alloys that combine high saturation magnetic induction and low coercivity remains a significant challenge. For amorphous and nanocrystalline soft magnetic alloys, achieving high saturation magnetic induction requires selecting ferromagnetic elements with high magnetic moments. However, the addition of excessive ferromagnetic elements can affect the alloy's amorphous forming ability. For example, iron is a commonly used element to improve saturation magnetic induction, but excessive Fe can make it difficult for the alloy to form an amorphous structure, leading to a sharp increase in coercivity. Furthermore, while adding glass-forming elements can improve glass-forming ability, these elements often deteriorate the alloy's saturation magnetic induction. For amorphous alloys requiring nanocrystallization to enhance saturation magnetic induction, the size, distribution, and phase structure of the nanocrystals have a significant impact on saturation magnetic induction. Due to the strong exchange coupling between nanoscale grains, the coercivity is also proportional to the sixth power of the grain size. Therefore, controlling the nanocrystalline structure is crucial for improving the soft magnetic properties of nanocrystalline alloys. Currently, only the FINEMET alloy can be industrially prepared as nanocrystalline material, with a saturation magnetic flux density of only 1.24 T and a coercivity of 0.5 A / m. The high Nb content in the FINEMET alloy can suppress grain growth, but it significantly reduces the alloy's saturation magnetic flux density. Makino and Menga et al. developed the NANOMET alloy, which can achieve a saturation magnetic flux density as high as approximately 1.86 T after nanocrystallization. However, due to the lack of elements to inhibit grain growth, its nanocrystallization process requires an extremely high heating rate and a very short annealing time; otherwise, abnormal grain growth will occur, leading to a sharp increase in coercivity. Furthermore, Ohta and Zhang Wei et al. developed a high-Cu-content nanocrystalline alloy. The competitive growth effect between pre-formed nuclei and α-Fe crystallized during annealing can effectively suppress grain growth, but the coercivity is still relatively high, approximately 5.5-10 A / m, which is significantly lower than that of alloys such as 1K101 and FINEMET. In summary, amorphous and nanocrystalline soft magnetic alloys that possess both high saturation magnetic induction and low coercivity have not yet been developed. Summary of the Invention

[0004] From the perspective of materials design and process route, existing high-B s (Saturation magnetic induction intensity) Amorphous / nanocrystalline soft magnetic alloys mainly follow the following two technical paths:

[0005] 1. Conventional amorphous alloys: These typically contain little or no Cu, and their magnetism primarily originates from the amorphous matrix. These alloys generally crystallize at the first initiation temperature (T0). x1 The following annealing (i.e., relaxation annealing) is performed to eliminate internal stress and optimize the magnetic structure, thereby increasing the permeability and reducing the coercivity, but the saturation magnetic induction intensity (B) is reduced. s Limited by the amorphous phase itself, the potential for improvement is limited.

[0006] 2. Conventional nanocrystalline alloys (represented by Finemet, Nanomet, etc.): Their core design involves first obtaining a completely amorphous precursor, then adding a small amount of Cu (usually about 1 at.%), followed by a process with a higher T... x1 During the crystallization annealing process, Cu atoms agglomerate in the amorphous matrix to form clusters, serving as heterogeneous nucleation sites for α-Fe(Si) grains, thereby promoting the precipitation of a large number of fine, uniform nanocrystals. However, Finemet series alloys have low saturation magnetic induction, and Nanomet series alloys require extremely high heating rates and extremely short holding times, resulting in a narrow process window.

[0007] The present invention aims to at least alleviate or resolve at least one of the aforementioned problems to some extent.

[0008] In one aspect of the invention, an amorphous nanocrystalline soft magnetic alloy with high saturation magnetic induction and low coercivity is proposed, wherein the alloy composition is M. a B b Si c Cu d Q e Where M is Fe, or M includes at least one of Co and Ni and Fe, and the atomic percentage content of Fe in M ​​is ≥75%; Q is at least one of C, P, and Cr; a, b, c, d, and e are the atomic percentage contents of the corresponding elements in the alloy, a+b+c+d+e=100, and satisfying: 81 ≤ a ≤ 87, 10 ≤ b ≤ 17, 0 ≤ c ≤ 5, 1.0 ≤ d ≤ 1.8; 0 ≤ e ≤ 4.0; The alloy in the quenched state contains at least one of an amorphous matrix and α-Fe nanophases, crystal nuclei, or ferromagnetic atomic clusters with a size less than 20 nm; after low-temperature relaxation annealing, the alloy has a saturation magnetic induction of 1.71-1.97 T and a coercivity of 1.0-7.0 A / m.

[0009] The high content of ferromagnetic elements (Fe, Co, Ni, etc.) results in a high overall magnetic moment for the alloy, with Fe accounting for over 75% of the atomic content (0.75a). The high Cu content leads to small clusters, grains, or nuclei in the quenched state and a high number density, making them less prone to growth during annealing. Instead of crystallization annealing, low-temperature relaxation annealing is used to achieve a saturation magnetic induction of 1.71-1.97 T and a coercivity of 1.0-7.0 A / m. Compared to existing amorphous and nanocrystalline alloys, the alloy proposed in this invention possesses certain quenched nuclei, nanophases, and / or ferromagnetic atomic clusters in the quenched state. Furthermore, low-temperature relaxation annealing retains a large amount of amorphous matrix, and the process conditions are flexible, allowing for extremely high saturation magnetic induction and extremely low coercivity even under long-term annealing conditions.

[0010] In some embodiments of the present invention, the alloy satisfies: 81.5 ≤ a ≤ 85.

[0011] In some embodiments of the present invention, the alloy satisfies: 10.5 ≤ b ≤ 14.5, and / or, 1.4 ≤ d ≤ 1.5.

[0012] In some embodiments of the invention, the alloy satisfies: 1 ≤ c ≤ 2.7, and / or, 0 ≤ e ≤ 3.6.

[0013] In some embodiments of the present invention, the alloy satisfies one of the following conditions: The alloy has the following composition: Fe 68 Co 17 B 12.5 Si1Cu 1.5 ; The alloy has the following composition: Fe 74 Co 11 B 12.5 Si1Cu 1.5 ; The alloy has the following composition: Fe 80 Co5B 12.5 Si1Cu 1.5 ; The alloy has the following composition: Fe 85 B 12.5 Si1Cu 1.5 ; The alloy has the following composition: Fe 82 B 14.5 Si2Cu 1.5 ; The alloy has the following composition: Fe 82 B 14.5 Si2Cu 1.5; The alloy has the following composition: Fe 81.5 B 11.5 Si 2.7 C2P 0.8 Cu 1.5 ; The alloy has the following composition: Fe 84.5 B 10.5 Si 1.5 C 1.3 P 0.7 Cu 1.5 ; The alloy has the following composition: Fe 82.5 B 11 Si 2.2 C2P 0.8 Cu 1.5 ; The alloy has the following composition: Fe 83 B 11 Si 1.9 C2P 0.6 Cu 1.5 ; The alloy has the following composition: Fe 82.2 B 11 Si 1.8 C 2.8 P 0.8 Cu 1.4 .

[0014] In another aspect of the present invention, a method for preparing the aforementioned amorphous nanocrystalline soft magnetic alloy is provided, the method comprising the following steps: Step 1: Weigh the raw materials according to the composition of the alloy, and repeatedly melt them in an induction melting furnace at least 3 times to make a master alloy ingot; Step 2: Using a single-roller spin quenching process, the master alloy ingot is melted and then spin quenched to prepare an amorphous alloy strip; Step 3: The amorphous alloy strip is subjected to a temperature below the first initiation crystallization temperature (T). x1 The amorphous nanocrystalline soft magnetic alloy is obtained by isothermal heat treatment at a temperature of 50-120 ℃ for a holding time of 30-90 min, followed by cooling to room temperature.

[0015] The initial crystallization temperature can be obtained by measuring the quenched amorphous material using a scanning differential calorimeter (DSC) to obtain a DSC curve. The initial crystallization temperature T can then be determined from the DSC curve. x1 First crystallization peak temperature T p1 Second initial crystallization temperature T x2 Second crystallization peak temperature T p2Optimized annealing temperature and annealing time can be achieved by adjusting the annealing temperature of amorphous alloy strips at the first initial crystallization temperature (T). x1 The results were obtained by conducting experiments under the following conditions: 50-120 ℃ and a holding time of 30-90 min.

[0016] The method proposed in this invention achieves a significant improvement in magnetic properties through synergistic optimization of composition design and process. This method employs a nanocrystalline alloy design approach, utilizing the fine nanocrystalline particles, nuclei, or atomic clusters present in the quenched alloy to enhance saturation magnetic induction. An amorphous alloy is then subjected to structural relaxation annealing below the first crystallization temperature, maintaining a large amorphous matrix to preserve the alloy's low coercivity. Since it does not require the preparation of a completely amorphous structure in the quenched state, this method overcomes the limitation of amorphous alloy formation capability under high ferromagnetic element content. Furthermore, the unique alloy composition and structural design enable it to achieve excellent soft magnetic properties during prolonged annealing below the crystallization temperature, demonstrating promising industrial prospects.

[0017] To facilitate comparison between the technical solutions of this invention and those of amorphous alloys and nanocrystalline alloys in related technologies, the process and alloy structure characteristics of different paths are listed in Table 1.

[0018] Table 1. Comparison of process and alloy structure characteristics of different technical approaches

[0019] In some embodiments of the present invention, a single-roll spin quenching process is used to melt the master alloy ingot and prepare an amorphous alloy strip with a thickness of 16-25 μm at a linear velocity of 20-40 m / s.

[0020] In some embodiments of the present invention, the method satisfies at least one of the following conditions: the raw material is repeatedly melted in an induction melting furnace 3-5 times to produce the master alloy ingot; in step one, the melting time for each melting is not less than 3 minutes; in step one, the vacuum degree is ≤3×10 -3 The smelting is carried out under a protective atmosphere, wherein the protective atmosphere includes at least one of argon and nitrogen.

[0021] In some embodiments of the present invention, the master alloy ingot is crushed, and then the crushed master alloy ingot is melted and quenched by a single-roll quenching process to prepare an amorphous alloy strip.

[0022] In some embodiments of the present invention, in step three, the cooling to room temperature is achieved by water quenching or air cooling.

[0023] In some embodiments of the present invention, in step three, the isothermal heat treatment is performed under the influence of no magnetic field or a magnetic field. Attached Figure Description

[0024] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0025] Figure 1 This is a bright-field high-magnification transmission electron microscope image of the amorphous alloy strip (quenched state) in Example 1.

[0026] Figure 2 The heat flow-temperature curve, i.e., the DSC curve, is obtained by scanning differential calorimetry (DSC) of the amorphous alloy strip (quenched state) in Example 1.

[0027] Figure 3 This is a bright-field high-magnification transmission electron microscope image of the amorphous alloy strip (quenched state) in Example 5. Detailed Implementation

[0028] The following embodiments are provided to better understand the present invention and are not limited to the preferred embodiments described. They do not constitute a limitation on the content and scope of protection of the present invention. Any product that is the same as or similar to the present invention, derived by any person under the guidance of the present invention or by combining the features of the present invention with other prior art, falls within the protection scope of the present invention.

[0029] For experiments not specifically described in the examples, the procedures or conditions should be followed according to the conventional experimental procedures described in the literature in this field. Reagents or instruments whose manufacturers are not specified are all commercially available conventional reagent products.

[0030] In one aspect of the invention, an amorphous nanocrystalline soft magnetic alloy with high saturation magnetic induction and low coercivity is proposed. The alloy composition is M. a B b Si c Cu d Q eThe alloy is defined as follows: M is Fe, or M includes at least one of Co and Ni and Fe, with the atomic percentage content of Fe in M ​​being ≥75%; Q is at least one of C, P, and Cr; a, b, c, d, and e are the atomic percentage contents of the corresponding elements in the alloy, a+b+c+d+e=100, and satisfying: 81 ≤ a≤ 87, 10 ≤ b ≤ 17, 0 ≤ c ≤ 5, 1.0 ≤ d ≤ 1.8; 0 ≤ e ≤ 4.0; the alloy in the quenched state contains at least one of an amorphous matrix and α-Fe nanophases or crystal nuclei or ferromagnetic atomic clusters with a size less than 20 nm; after low-temperature relaxation annealing, the saturation magnetic induction intensity of the alloy is 1.71-1.97 T, and the coercivity is 1.0-7.0 A / m. The above alloy possesses both high saturation magnetic induction intensity and low coercivity, and has good application prospects.

[0031] Element M is a ferromagnetic element. The atomic percentage content of Fe in M ​​is ≥75%, which can increase the total magnetic moment of the alloy, thereby improving the magnetic properties of the alloy.

[0032] In some embodiments, the atomic percentage content of Fe in M ​​can be ≥80%.

[0033] In some embodiments, a can be 81, 83, 84, 86, etc., b can be 12, 13, 14, 15, 16, etc., c can be 1, 2, 3, 4, etc., d can be 1.1, 1.3, 1.6, 1.7, etc., and e can be 0, 0.5, 1.0, 1.5, 1.8, etc.

[0034] In some embodiments of the present invention, a can be 81.5-85, thereby the alloy has a high content of ferromagnetic elements, which is beneficial to balancing the saturation magnetic induction intensity and coercivity of the alloy, thereby improving the soft magnetic properties of the alloy.

[0035] In some embodiments of the present invention, b can be 10.5-14.5, thereby further optimizing the boron content in the alloy and improving the overall performance of the alloy.

[0036] In some embodiments, d can be 1.4-1.5.

[0037] In some embodiments of the present invention, c can be 1-2.7. By further optimizing the silicon content in the alloy, the saturation magnetic induction intensity and coercivity of the alloy can be better balanced.

[0038] In some embodiments, e can be 0-3.6. In other embodiments, e can be 2-3.6.

[0039] It should be noted that the raw materials may contain a small amount of impurities, or a small amount of impurities may be unavoidably introduced during the preparation process. Therefore, the amorphous nanocrystalline soft magnetic alloy proposed in this invention may contain an unavoidable small amount of impurities.

[0040] In another aspect of the present invention, a method for preparing the aforementioned amorphous nanocrystalline soft magnetic alloy is provided. In some embodiments of the present invention, the preparation method may include the following steps: Step 1: Weigh the raw materials according to the alloy composition, and repeatedly melt them in an induction melting furnace at least 3 times to make a master alloy ingot.

[0041] In this step, the melting process is repeated at least three times to ensure uniform mixing of the components and obtain a master alloy ingot with homogeneous composition. In some embodiments, the raw materials can be repeatedly melted in an induction melting furnace 3-5 times to produce the master alloy ingot.

[0042] In some embodiments, the melting time for each melting process may be no less than 3 minutes, for example, the melting time for each melting process may be 3 minutes, 4 minutes, 5 minutes, etc.

[0043] In some embodiments, Fe, Co, Ni, Cu, Si, B, Cr, C, and P elements are all sourced from elemental forms. The purity of these elemental sources can be greater than or equal to 99.9%.

[0044] In other embodiments, C and P elements can be derived from iron-carbon alloys (C 5 wt.%, purity 99.99%) and iron-phosphorus alloys (P 26.1 wt.%, purity 99.5%), while other elements can be derived from elemental raw materials. It should be noted that when iron-carbon alloys and / or iron-phosphorus alloys are used, the iron element is included in the total amount, and the remaining iron element in the target product is provided by elemental iron.

[0045] In some embodiments, in step one, the vacuum degree can be ≤3×10 -3 Smelting raw materials under Pa conditions.

[0046] In some other embodiments, in step one, the raw materials can be melted under a protective atmosphere, such as an argon atmosphere, a nitrogen atmosphere, or a mixed atmosphere of argon and nitrogen.

[0047] Step 2: Using a single-roller spin quenching process, the master alloy ingot is melted and then spin quenched to prepare amorphous alloy strips.

[0048] The amorphous alloy strip in step two is the quenched state of the alloy, which is an amorphous strip material formed by rapid solidification.

[0049] After the alloy of the present invention is prepared as an amorphous alloy strip (quenched state), it not only contains an amorphous matrix, but also contains at least one of α-Fe nanophase with a size of less than 20 nm, crystal nuclei, and ferromagnetic atom clusters. These small-sized structures can improve the saturation magnetic induction intensity of the alloy.

[0050] In some embodiments, a single-roll spin quenching process is used to melt the master alloy ingot and spin it at a linear velocity of 20-40 m / s to prepare an amorphous alloy strip with a thickness of 16-25 μm. For example, the linear velocity of the spin can be 20 m / s, 25 m / s, 30 m / s, 35 m / s, 40 m / s, etc., and the thickness of the amorphous alloy strip can be 16 μm, 18 μm, 20 μm, 23 μm, 25 μm, etc. The amorphous alloy strip prepared under the above conditions contains fine nanocrystalline particles, crystal nuclei, and / or ferromagnetic atomic clusters. These fine structures can improve the saturation magnetic induction intensity of the alloy after low-temperature relaxation annealing.

[0051] In some embodiments, in step two, the master alloy ingot can be directly melted and then spun.

[0052] In other embodiments, the master alloy ingot can be crushed first, and then the crushed master alloy ingot can be melted and quenched using a single-roll spin quenching process to prepare amorphous alloy strips. For example, the master alloy ingot can be crushed at room temperature.

[0053] Step 3: The amorphous alloy strip is subjected to isothermal heat treatment at a temperature 50-120 ℃ lower than the first initial crystallization temperature. The holding time of the isothermal heat treatment is 30-90 min, and then it is cooled to room temperature to obtain an amorphous nanocrystalline soft magnetic alloy.

[0054] In some embodiments, the amorphous alloy strip can be subjected to isothermal heat treatment at a temperature 60 °C, 80 °C, 100 °C, or 110 °C below the first initiation crystallization temperature, and the holding time of the isothermal heat treatment can be 40 min, 50 min, 60 min, 70 min, or 80 min. Relaxation annealing of the amorphous alloy strip below the first initiation crystallization temperature can retain a large amount of amorphous matrix, thereby maintaining a low coercivity in the alloy.

[0055] In some embodiments, isothermal heat treatment may be performed under the influence of a magnetic field. In other embodiments, isothermal heat treatment may be performed under conditions without a magnetic field.

[0056] In some embodiments, after isothermal heat treatment, the alloy can be cooled to room temperature by water quenching or air cooling.

[0057] In summary, this invention significantly enhances the magnetic properties of alloys through synergistic optimization of alloy composition and process. The fine nanophases, crystal nuclei, and / or ferromagnetic atom clusters present in the quenched alloy can increase the alloy's saturation magnetic induction. Low-temperature relaxation annealing of the amorphous alloy strips below the first initiation crystallization temperature helps maintain a large amount of amorphous matrix to preserve low coercivity. The method proposed in this invention does not require the preparation of a completely amorphous structure in the quenched state, thus overcoming the limitations of amorphous alloy formation capability under high ferromagnetic element content.

[0058] The alloy proposed in this invention has excellent soft magnetic properties and has good application prospects in fields such as distribution transformers, power transformers, high-frequency transformers, chokes, pulse transformers, saturated reactors, switching power supplies, and interface equipment.

[0059] The present application will be described below through specific embodiments. Those skilled in the art will understand that the specific embodiments below are merely for illustrative purposes and do not limit the scope of the present application in any way. In the following embodiments and comparative examples, C and P elements are respectively made from iron-carbon alloy (C 5 wt.%, purity 99.99%) and iron-phosphorus alloy (P 26.1 wt.%, purity 99.5%). Co, Cu, Si, B and the remaining Fe elements are all made from elemental raw materials with a purity ≥99.9%.

[0060] Example 1 This embodiment provides a high saturation magnetic induction intensity and low coercivity iron-based amorphous nanocrystalline alloy (Fe). 68 Co 17 B 12.5 Si1Cu 1.5 Its preparation method includes the following steps: (1) Prepare the raw materials according to the composition of the target alloy and melt them in a vacuum induction furnace (vacuum degree less than 3×10). -3 Pa) The prepared raw materials are repeatedly melted 3-5 times to produce a master alloy ingot.

[0061] (2) The broken master alloy ingot is prepared into strip material, namely iron-based amorphous nanocrystalline alloy precursor (amorphous alloy strip), by using copper wheel single roller spinning method.

[0062] (3) The prepared iron-based amorphous nanocrystalline alloy precursor is subjected to vacuum magnetic field heat treatment (i.e., annealing). Specifically, the strip is placed in a magnetic field heat treatment furnace preheated to 280 °C and held for 60 min. After that, it is water quenched to obtain iron-based amorphous nanocrystalline alloy strip samples.

[0063] (4) The magnetic properties of the iron-based amorphous nanocrystalline alloy strip sample were tested. The coercivity (H) of the amorphous nanocrystalline alloy strip was measured using a DC hysteresis loop meter and a vibrating sample magnetometer. c ) and saturation magnetic induction (B s The test results are shown in Table 2.

[0064] The TEM bright-field image of the quenched amorphous alloy strip in Example 1 is as follows: Figure 1 As shown, by Figure 1 A small amount of α-Fe phase can be observed precipitated in the quenched state of the alloy. Figure 1 The small black and white dots inside the circle drawn in the middle are nanocrystalline particles.

[0065] The DSC curve of the quenched amorphous alloy strip in Example 1 is as follows: Figure 2 As shown, according to Figure 2 The first initial crystallization temperature of the alloy can be determined.

[0066] Example 2 This embodiment provides an iron-based amorphous nanocrystalline alloy with high saturation magnetic induction and low coercivity, prepared using essentially the same method as in Example 1. The difference is that the alloy in this embodiment is composed of Fe. 74 Co 11 B 12.5 Si1Cu 1.5 .

[0067] Example 3 This embodiment provides an iron-based amorphous nanocrystalline alloy with high saturation magnetic induction and low coercivity, prepared using essentially the same method as in Example 1. The difference is that the alloy in this embodiment is composed of Fe. 80 Co5B 12.5 Si1Cu 1.5 .

[0068] Example 4 This embodiment provides an iron-based amorphous nanocrystalline alloy with high saturation magnetic induction and low coercivity, prepared using essentially the same method as in Example 1. The difference is that the alloy in this embodiment is composed of Fe. 85 B 12.5 Si1Cu 1.5 .

[0069] Example 5 This embodiment provides an iron-based amorphous nanocrystalline alloy with high saturation magnetic induction and low coercivity, prepared using essentially the same method as in Example 1. The difference is that the alloy in this embodiment is composed of Fe. 82 B 14.5Si2Cu 1.5 In step (3), annealing is performed under non-magnetic conditions at a temperature of 300 °C.

[0070] The TEM bright-field image of the quenched amorphous alloy strip in Example 5 is as follows: Figure 3 As shown, by Figure 3 A small amount of α-Fe phase can be observed precipitated in the quenched state of the alloy.

[0071] Example 6 This embodiment provides an iron-based amorphous nanocrystalline alloy with high saturation magnetic induction and low coercivity, prepared using essentially the same method as in Example 1. The difference is that the alloy in this embodiment is composed of Fe. 82 B 14.5 Si2Cu 1.5 In step (3), annealing is performed under non-magnetic conditions at a temperature of 320 °C.

[0072] Example 7 This embodiment provides an iron-based amorphous nanocrystalline alloy with high saturation magnetic induction and low coercivity, prepared using essentially the same method as in Example 1. The difference is that the alloy in this embodiment is composed of Fe. 81.5 B 11.5 Si 2.7 C2P 0.8 Cu 1.5 In step (3), annealing is performed under non-magnetic conditions at a temperature of 300 °C.

[0073] Example 8 This embodiment provides an iron-based amorphous nanocrystalline alloy with high saturation magnetic induction and low coercivity, prepared using essentially the same method as in Example 1. The difference is that the alloy in this embodiment is composed of Fe. 82.5 B 11 Si 2.2 C2P 0.8 Cu 1.5 In step (3), annealing is performed under non-magnetic conditions at a temperature of 300 °C.

[0074] Example 9 This embodiment provides an iron-based amorphous nanocrystalline alloy with high saturation magnetic induction and low coercivity, prepared using essentially the same method as in Example 1. The difference is that the alloy in this embodiment is composed of Fe. 84.5 B 10.5 Si 1.5 C 1.3 P 0.7 Cu 1.5In step (3), annealing is performed under non-magnetic conditions at a temperature of 290 °C.

[0075] Example 10 This embodiment provides an iron-based amorphous nanocrystalline alloy with high saturation magnetic induction and low coercivity, prepared using essentially the same method as in Example 1. The difference is that the alloy in this embodiment is composed of Fe. 83 B 11 Si 1.9 C2P 0.6 Cu 1.5 No magnetic field is required. In step (3), annealing is performed under non-magnetic conditions at a temperature of 300 °C.

[0076] Example 11 This embodiment provides an iron-based amorphous nanocrystalline alloy with high saturation magnetic induction and low coercivity, prepared using essentially the same method as in Example 1. The difference is that the alloy in this embodiment is composed of Fe. 82.2 B 11 Si 1.8 C 2.8 P 0.8 Cu 1.4 In step (3), annealing is performed under non-magnetic conditions at a temperature of 300 °C.

[0077] Comparative Example 1 The alloy was prepared using a method essentially the same as that used in Example 1, except that the annealing temperature in step (3) of Comparative Example 1 was 370 °C.

[0078] Comparative Example 2 The alloy was prepared using a method essentially the same as that used in Example 3, except that the annealing temperature in step (3) of Comparative Example 2 was 360 °C.

[0079] The samples of Examples 2-11 and Comparative Examples 1-2 were tested for magnetic properties using the same method as in Example 1. The performance test results of each example and comparative example are shown in Table 2.

[0080] Table 2 H of each embodiment and comparative example c and B s Test Results

[0081] In the description of this specification, references to terms such as "some embodiments," "other embodiments," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment is included in at least one embodiment of this application. The illustrative expressions of the above terms in this specification do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in a suitable manner in any one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of those different embodiments or examples.

[0082] Although embodiments of this application have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting this application. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of this application.

Claims

1. An amorphous nanocrystalline soft magnetic alloy with high saturation magnetic induction and low coercivity, characterized in that, The alloy has the composition M. a B b Si c Cu d Q e Where M is Fe, or M includes at least one of Co and Ni and Fe, and the atomic percentage content of Fe in M ​​is ≥75%; Q is at least one of C, P, and Cr; a, b, c, d, and e are the atomic percentage contents of the corresponding elements in the alloy, a+b+c+d+e=100, and satisfying: 81 ≤ a ≤ 87， 10 ≤ b ≤ 17， 0 ≤ c ≤ 5， 1.0 ≤ d ≤ 1.8； 0 ≤ e ≤ 4.0； The alloy in the quenched state contains at least one of an amorphous matrix and α-Fe nanophases, crystal nuclei, or ferromagnetic atomic clusters with a size less than 20 nm; after low-temperature relaxation annealing, the alloy has a saturation magnetic induction of 1.71-1.97 T and a coercivity of 1.0-7.0 A / m.

2. The alloy according to claim 1, characterized in that, It satisfies: 81.5 ≤ a ≤ 85.

3. The alloy according to claim 1, characterized in that, Satisfy: 10.5 ≤ b ≤ 14.5, and / or, 1.4 ≤ d ≤ 1.

5.

4. The alloy according to claim 1, characterized in that, It satisfies: 1 ≤ c ≤ 2.7, and / or, 0 ≤ e ≤ 3.

6.

5. The alloy according to any one of claims 1-4, characterized in that, One of the following conditions must be met: The alloy has the following composition: Fe 68 Co 17 B 12.5 Si1Cu 1.5 ; The alloy has the following composition: Fe 74 Co 11 B 12.5 Si1Cu 1.5 ; The alloy has the following composition: Fe 80 Co5B 12.5 Si1Cu 1.5 ; The alloy has the following composition: Fe 85 B 12.5 Si1Cu 1.5 ; The alloy has the following composition: Fe 82 B 14.5 Si2Cu 1.5 ; The alloy has the following composition: Fe 82 B 14.5 Si2Cu 1.5 ; The alloy has the following composition: Fe 81.5 B 11.5 Si 2.7 C2P 0.8 Cu 1.5 ; The alloy has the following composition: Fe 84.5 B 10.5 Si 1.5 C 1.3 P 0.7 Cu 1.5 ; The alloy has the following composition: Fe 82.5 B 11 Si 2.2 C2P 0.8 Cu 1.5 ; The alloy has the following composition: Fe 83 B 11 Si 1.9 C2P 0.6 Cu 1.5 ; The alloy has the following composition: Fe 82.2 B 11 Si 1.8 C 2.8 P 0.8 Cu 1.4 .

6. A method for preparing the amorphous nanocrystalline soft magnetic alloy according to any one of claims 1-5, characterized in that, Includes the following steps: Step 1: Weigh the raw materials according to the composition of the alloy, and repeatedly melt them in an induction melting furnace at least 3 times to make a master alloy ingot; Step 2: Using a single-roller spin quenching process, the master alloy ingot is melted and then spin quenched to prepare an amorphous alloy strip; Step 3: The amorphous alloy strip is subjected to isothermal heat treatment at a temperature 50-120°C below the first initial crystallization temperature. The holding time of the isothermal heat treatment is 30-90 min, and then it is cooled to room temperature to obtain the amorphous nanocrystalline soft magnetic alloy.

7. The method according to claim 6, characterized in that, The master alloy ingot is melted using a single-roll spin quenching process, and amorphous alloy strips with a thickness of 16-25 μm are prepared at a linear velocity of 20-40 m / s.

8. The method according to claim 6 or 7, characterized in that, At least one of the following conditions must be met: The raw materials are repeatedly melted in an induction melting furnace 3-5 times to produce the master alloy ingot; In step one, each melting process shall take no less than 3 minutes; In step one, the vacuum degree is ≤3×10 -3 The smelting is carried out under a protective atmosphere, wherein the protective atmosphere includes at least one of argon and nitrogen.

9. The method according to claim 6 or 7, characterized in that, The master alloy ingot is crushed, and then the crushed master alloy ingot is melted and quenched using a single-roll quenching process to prepare amorphous alloy strips.

10. The method according to claim 6 or 7, characterized in that, In step three, the cooling to room temperature is achieved by water quenching or air cooling; and / or, the isothermal heat treatment is performed without a magnetic field or under the influence of a magnetic field.

Images