An iron-based nanocrystalline soft magnetic alloy powder, a soft magnetic composite material and a preparation method thereof

Abstract

The application discloses an iron-based nanocrystalline soft magnetic alloy powder, a soft magnetic composite material and a preparation method thereof. a B b C c Si d Cu e M m Q q Z z X x , wherein M is at least one of Co and Ni, Q is at least one of a pre-transition group element, a semi-metal element, a rare earth element and Al, X is at least one of O, N, S and a halogen element, wherein 70<=a+m<=75, 8<=b<=18, 0<=c<=5, 10<=d<=15, 0<=m<=10, 1.3<=e<=2.5, 0<=q<=2, 0<=z<=1, 0<=x<=0.2, and 22<=b+c+d<=30, a+b+c+d+e+m+q+z+x=100; the soft magnetic composite material is composed of the iron-based nanocrystalline soft magnetic alloy powder disclosed in the application, an alloy state soft magnetic powder and a binder. The iron-based nanocrystalline soft magnetic alloy powder and the soft magnetic composite material provided by the application have excellent soft magnetic performance, good processability and low cost, and have a very wide application prospect.

Description

Technical Field

[0001] This invention relates to the field of soft magnetic materials technology, and more specifically, to an iron-based nanocrystalline soft magnetic alloy powder, a soft magnetic composite material, and a method for preparing the same. Background Technology

[0002] The rapid development of new energy vehicles, 5G communications, and smart homes is placing increasingly higher demands on the performance of power electronic devices. This necessitates the development of novel soft magnetic materials to meet the requirements of high frequency, energy efficiency, and miniaturization. This necessitates achieving high-frequency stability, low coercivity, low loss, and high saturation magnetization (M) in soft magnetic materials. s Performance metrics. Currently commonly used high M... s The powders are mainly iron-silicon powder, iron-silicon-chromium powder and permalloy powder, but they all have the problem of high high-frequency loss, which does not conform to the current trend of energy saving and high frequency in power electronic equipment. Furthermore, permalloy powder is expensive, which to some extent hinders their application range.

[0003] Soft magnetic composite materials are made by pressing ferromagnetic particles coated with an insulating agent using powder metallurgy technology. They possess excellent soft magnetic properties, including low eddy current loss, high resistivity, ease of machining, and a wide operating frequency range, making them widely used in inductors in electronic components. As inductors trend towards miniaturization, soft magnetic composite materials must evolve in ways that facilitate this miniaturization. This necessitates low core loss, high permeability, high saturation magnetization, and excellent high-frequency magnetic properties. The performance of the soft magnetic powder and the selection of the insulating binder have a crucial impact on the performance of soft magnetic composite materials. Blending soft magnetic powders of different types, particle sizes, and hardnesses can significantly increase the filling density of the soft magnetic composite material and reduce the voids between powder particles. This will improve the permeability of electronic devices. Furthermore, blending small-diameter powders can reduce the average particle size, lowering interparticle eddy current losses in the soft magnetic composite material, thereby significantly reducing high-frequency losses. Currently used high-M... s Soft magnetic composite materials are mainly composed of iron-silicon and iron-nickel soft magnetic composite materials, but both have the problem of high high-frequency loss, which is not conducive to the high-frequency operation of power electronic devices. In addition, the iron-nickel soft magnetic composite material has a high content, which limits its application range.

[0004] Iron-based nanocrystalline soft magnetic alloys possess characteristics such as low magnetostriction coefficient, low loss, high permeability, and high MnO. s Soft magnetic composite materials have attracted widespread attention from scientists and industry due to their excellent high-frequency magnetic properties. These properties include low high-frequency eddy current losses, good frequency characteristics, and M... sIt offers superior advantages. Preparing iron-based nanocrystalline soft magnetic alloys into powder and then using powder metallurgy to fabricate soft magnetic composite materials combines the advantages of both, creating a new generation of high-performance soft magnetic materials—nanocrystalline soft magnetic composites—driving the development of high-frequency, high-performance electronic devices, power equipment, and related industries. Currently, iron-based nanocrystalline soft magnetic alloys are mainly designed and developed for the high-cooling-rate single-roller spinning method, which has weak amorphous formation capabilities. It requires first obtaining a completely amorphous precursor strip using the single-roller spinning method, then heat-treating it to obtain the nanocrystalline alloy, and finally crushing it using ball milling to obtain soft magnetic powder. However, these crushed strip powders have sharp edges, making insulation coating difficult, resulting in high losses in the soft magnetic composite material and limiting its application at higher frequencies. Spherical or ellipsoidal powders obtained using the atomization method have good coating properties, effectively reducing the losses of soft magnetic composite materials at high frequencies.

[0005] Typical iron-based nanocrystalline soft magnetic alloy systems include Fe-Si-B-Nb-Cu alloys and Fe-Si-BP-Cu alloys. For Fe-Si-B-Nb-Cu alloys, the advantages are low coercivity, high permeability, and low loss, which stem from their nucleation mechanism: Cu atoms separate and act as nucleation centers. The addition of Nb or other slowly diffusing components (such as Ta, V, and W) restricts crystal growth, thereby reducing grain size. Niobium and boron are repelled from the α-Fe primary grains and allocated to the remaining amorphous phase. The enrichment of Nb and B stabilizes the remaining amorphous phase, thus inhibiting the growth of α-Fe primary crystals. However, the M... s With a power density of only 1.2T, the soft magnetic composite material has a low power density, which is detrimental to the miniaturization and high-current operation of electronic devices and power equipment. Furthermore, the powder processing of this type of nanocrystalline alloy is complex, requiring the preparation of an amorphous precursor followed by heat treatment at approximately 600℃ for one hour to obtain its excellent soft magnetic properties. The M... s While the temperature reaches as high as 1.9T, it is difficult to obtain a completely amorphous precursor through atomization. Furthermore, a dense and uniform fine nanocrystalline structure can only be obtained at a relatively fast heating rate. The nanocrystalline structure and soft magnetic properties of the powder place very stringent requirements on the heat treatment process, requiring high heating rates (200-9000℃ / min) that are difficult to achieve under industrial conditions. The magnetic properties are very poor under conventional heat treatment processes. In addition, the alloy contains volatile and flammable phosphorus (P) element. The volatilization of P element during alloy preparation makes it difficult to control the alloy composition and poses a flammability risk. The poor processability seriously hinders the large-scale production of its powder and soft magnetic composite materials.

[0006] In summary, nanocrystalline soft magnetic composite materials possess excellent soft magnetic properties, perfectly aligning with the current development trends in fields such as smart terminals, 5G communications, industrial internet, and new energy vehicles. However, the low Ms (Mean Magnetic Properties) or poor processability of existing iron-based nanocrystalline soft magnetic alloys severely restricts the application scope and industrialization of nanocrystalline powder cores. Therefore, developing a nanocrystalline powder core with high Ms is crucial. s The development of high-performance soft magnetic composite materials based on nanocrystalline alloy powders with excellent soft magnetic properties and processability will have significant industrialization value. Summary of the Invention

[0007] To address the shortcomings of current nanocrystalline alloy powders and soft magnetic composite materials, this invention provides a method that combines high M s This invention provides iron-based nanocrystalline soft magnetic alloy powder with excellent soft magnetic properties, processability, and low cost. It also provides soft magnetic composite materials and their preparation methods.

[0008] This invention provides an iron-based nanocrystalline soft magnetic alloy powder with the atomic percentage molecular formula Fe. a B b C c Si d Cu e M m Q q Z z X x Where M is at least one of Co and Ni, Q is at least one of a pre-transition element, a half-metal element, a rare earth element, and Al, wherein the pre-transition element is Ti, V, Cr, Mn, Y, Zr, Nb, Mo, Hf, Ta, or W, the half-metal element is Ge, Sn, As, or Sb, Z is at least one of Au, Ag, and a platinum group metal, X is at least one of O, N, S, and a halogen element, 70≤a+m≤75, 8≤b≤18, 0≤c≤5, 10≤d≤15, 0≤m≤10, 1.3≤e≤2.5, 0≤q≤2, 0≤z≤1, 0≤x≤0.2, and 22≤b+c+d≤30, a+b+c+d+e+m+q+z+x=100.

[0009] Based on the combined effect of the elements and their contents provided in this application, the iron-based nanocrystalline soft magnetic alloy powder provided by this invention can be directly obtained from the master alloy by atomization without the need for subsequent heat treatment. The atomization method includes, but is not limited to, gas atomization, water atomization, water-gas combined atomization, rotary water atomization, and multi-stage pulverization atomization, with a short preparation process and simple technology.

[0010] The iron-based nanocrystalline soft magnetic alloy powder provided by this invention does not contain volatile P element, and its composition is easy to control; and it does not contain or only contains a small amount of high-cost elements such as Co, Ni and Nb, so the material cost is low.

[0011] The iron-based nanocrystalline soft magnetic alloy powder provided by this invention is spherical or ellipsoidal, with a smooth surface and no sharp edges, which facilitates insulation coating treatment, helps to reduce the loss of soft magnetic composite materials, and improves the stability of soft magnetic composite materials in high-frequency applications.

[0012] The iron-based nanocrystalline soft magnetic alloy powder provided by this invention has excellent soft magnetic properties. The average size of the α-Fe grains in the powder is 10-18 nm, and the saturation magnetization M of the powder is [missing information]. s 150.0-170.0 emu / g, coercivity H c It is 3.0-7.0 Oe.

[0013] Optionally, the sum of the atomic percentages of Fe and M elements is 72 ≤ a + m ≤ 74, and the atomic percentage of M element is 0 ≤ m ≤ 5. In iron-based nanocrystalline soft magnetic alloy powder, Fe element is used as the magnetic source, and a higher Fe content helps to obtain high M content. s Nanocrystalline alloys. By controlling the content of Cu, metalloid elements, and other trace elements, and combining them with Fe, the alloy powder can form a multiphase structure in which fine α-Fe grains are distributed in the amorphous phase during atomization. The interaction between the grains and the amorphous phase can significantly reduce magnetocrystalline anisotropy and magnetostriction coefficient, thereby giving the powder excellent soft magnetic properties. Co and Ni are also common ferromagnetic elements, but their costs are high, and adding large amounts will reduce the M of the alloy powder. s Therefore, replacing Fe with a small amount of Co or Ni in the iron-based nanocrystalline soft magnetic alloy powder can also give the powder a higher M value. s And it will not significantly increase the raw material cost of alloy powder.

[0014] Optionally, the atomic percentage of B in the iron-based nanocrystalline soft magnetic alloy powder is 10 ≤ b ≤ 15, the atomic percentage of C in the iron-based nanocrystalline soft magnetic alloy powder is 0 ≤ c ≤ 3, and the atomic percentage of Si in the iron-based nanocrystalline soft magnetic alloy powder is 11 ≤ d ≤ 14, and 24 < b + c + d ≤ 28. By controlling the content of specific metalloid elements and the total content of metalloid elements in the iron-based nanocrystalline soft magnetic alloy powder, it helps the alloy to obtain good amorphous forming ability, thereby suppressing the precipitation of non-soft magnetic Fe-B compounds during atomization, forming a nanocrystalline structure containing only nanoscale α-Fe grains and amorphous phases, and enabling the powder to obtain high M s And excellent soft magnetic properties.

[0015] Optionally, the atomic percentage of Cu in the iron-based nanocrystalline soft magnetic alloy powder is 1.5 ≤ f ≤ 2.0. Cu in the iron-based nanocrystalline soft magnetic alloy promotes the nucleation of the α-Fe phase. Sufficient Cu is necessary for the formation of fine α-Fe grains during atomization, but excessive Cu can lead to the formation of non-soft magnetic Fe-B compounds in the powder. Therefore, a suitable Cu content in the iron-based nanocrystalline soft magnetic alloy powder is beneficial for the formation of high-number-density and fine-sized nano-α-Fe grains, enabling the powder to exhibit excellent soft magnetic properties.

[0016] Optionally, the atomic percentage of Q in the iron-based nanocrystalline soft magnetic alloy powder is 0 ≤ q ≤ 1. Adding Q to the iron-based nanocrystalline soft magnetic alloy powder helps suppress the precipitation of non-soft magnetic Fe-B compounds, but excessive amounts will significantly reduce the alloy's molecular weight (M). s Therefore, the presence of a small amount of Q element in the iron-based nanocrystalline soft magnetic alloy powder helps the powder form a multiphase structure in which nano-α-Fe grains are distributed in the amorphous phase and exhibits excellent soft magnetic properties, without excessively reducing the M of the powder. s .

[0017] Optionally, the atomic percentage of Z in the iron-based nanocrystalline soft magnetic alloy powder is 0 ≤ z ≤ 0.5. Adding Au, Ag, and platinum group metals to the nanocrystalline alloy can also promote α-Fe phase nucleation, but its effect is inferior to Cu, and the cost is higher. Therefore, containing a small amount of Z in the iron-based nanocrystalline soft magnetic alloy powder can also enable the powder to form fine α-Fe grains and exhibit excellent soft magnetic properties, without excessively increasing the raw material cost of the alloy powder.

[0018] Optionally, the atomic percentage of element X in the iron-based nanocrystalline soft magnetic alloy powder is 0 ≤ x ≤ 0.1. Common industrial raw materials often contain impurities such as O, N, S, and halogens. While small amounts of these elements do not significantly affect the structure and magnetic properties of the nanocrystalline powder, excessive amounts can severely degrade the structure and properties of the alloy. Therefore, the presence of a small amount of element X in the iron-based nanocrystalline soft magnetic alloy powder can still form fine α-Fe grains and exhibit excellent soft magnetic properties, and it allows the alloy powder to be produced using raw materials with lower purity.

[0019] The present invention also provides a soft magnetic composite material, comprising a mixed powder and a binder coating the mixed powder, wherein the mixed powder is the aforementioned iron-based nanocrystalline soft magnetic alloy powder and alloyed soft magnetic powder; wherein the alloyed soft magnetic powder is selected from at least one of carbonyl iron powder, iron-silicon powder, iron-silicon-chromium powder, iron-silicon-aluminum powder, and iron-nickel powder, and the mass of the alloyed soft magnetic powder accounts for 0-95% of the total mass of the mixed powder; the binder is selected from at least one of epoxy resin, phenolic resin, polyamide resin, and organosilicon resin, and the mass of the binder accounts for 1-5% of the total mass of the mixed powder.

[0020] The iron-based nanocrystalline soft magnetic alloy powder in the soft magnetic composite material provided by this invention has high M s The excellent soft magnetic properties of the composite material contribute to achieving low loss and high permeability under high-frequency conditions. The carbonyl iron powder in the soft magnetic composite material provided by this invention typically has a small particle size, which effectively reduces eddy current losses within particles under high-frequency conditions and also reduces the porosity of the soft magnetic composite material, thereby helping to reduce high-frequency losses and improve its permeability. The carbonyl iron powder, iron-silicon powder, iron-silicon-chromium powder, iron-silicon-aluminum powder, and iron-nickel powder in the soft magnetic composite material provided by this invention typically have low hardness, which helps to increase the pressing density of the soft magnetic composite material, thus giving it higher permeability.

[0021] The soft magnetic composite material provided by this invention has excellent high-frequency magnetic properties, with a loss (1MHz / 50mT) as low as 2000-4000mW / cm. 3 With a permeability (@100kHz) of 30-70, it has broad application prospects in high-performance power electronic devices.

[0022] The present invention also provides a method for preparing the soft magnetic composite material, comprising:

[0023] (1) The iron-based nanocrystalline soft magnetic powder is prepared by mixing the ingredients according to the atomic percentage composition formula of the iron-based nanocrystalline soft magnetic powder, and then melted evenly to form a master alloy.

[0024] (2) The master alloy was prepared into iron-based nanocrystalline soft magnetic powder by atomization method;

[0025] (3) After mixing the iron-based nanocrystalline soft magnetic powder obtained in step (2) with the alloy soft magnetic powder, a binder is added for coating to obtain the coated mixed soft magnetic powder.

[0026] (4) The coated mixed soft magnetic powder obtained in step (3) is pressed into a soft magnetic composite material and then subjected to heat treatment.

[0027] Optionally, the heat treatment process of the soft magnetic composite material in step (3) is: vacuum heating at 300-600℃ for 30-120 minutes.

[0028] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0029] (1) The iron-based nanocrystalline soft magnetic alloy powder provided by the present invention can be directly obtained from the master alloy by atomization without subsequent heat treatment. The process is simple and short, which can significantly improve production efficiency and reduce process cost. It does not contain volatile P element and the composition is easy to control.

[0030] (2) The iron-based nanocrystalline soft magnetic alloy powder provided by the present invention has high saturation magnetization, low coercivity, low magnetic loss and high permeability.

[0031] (3) The nanocrystalline alloy powder provided by the present invention is spherical or ellipsoidal in shape, which is easy to coat and helps the soft magnetic composite material made from it to obtain lower loss.

[0032] (4) The nanocrystalline alloy powder provided by the present invention does not contain or contains low levels of high-cost raw materials such as Co, Ni and Nb, thus the material cost is low.

[0033] (5) The soft magnetic composite material provided by the present invention has both low loss and high magnetic permeability, which helps to miniaturize and increase the frequency of power electronic devices, and has broad application prospects and good industrialization potential. Attached Figure Description

[0034] Figure 1 The image shows a scanning electron microscope (SEM) image of the iron-based nanocrystalline soft magnetic alloy powder prepared in Example 1.

[0035] Figure 2 The X-ray diffraction (XRD) pattern of the iron-based nanocrystalline soft magnetic alloy powder prepared in Example 1;

[0036] Figure 3 This is a transmission electron microscope (TEM) image of the iron-based nanocrystalline soft magnetic alloy powder prepared in Example 1.

[0037] Figure 4 Vibrational magnetic sample magnetometer (VSM) curves of soft magnetic powders prepared in Example 1 and Comparative Example 1;

[0038] Figure 5 The loss curves are for the soft magnetic composite materials prepared in Examples 1, 10 and Comparative Example 1.

[0039] Figure 6 The graphs show the permeability of the soft magnetic composite materials prepared in Examples 1, 10 and Comparative Example 1 as a function of frequency. Detailed Implementation

[0040] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. However, the scope of protection of the present invention is not limited to the following embodiments.

[0041] Examples 1-9 illustrate the preparation and performance testing process of the iron-based nanocrystalline soft magnetic alloy powder and soft magnetic composite material disclosed in this invention, while Comparative Examples 1-6 list the performance of common soft magnetic powders and their soft magnetic composite materials for comparison.

[0042] Example 1

[0043] In this embodiment, the alloy composition expression is: Fe 73.3 Si 12 B 13 Cu 1.7 The preparation and performance testing methods and steps for iron-based nanocrystalline soft magnetic alloy powder and soft magnetic composite materials are as follows:

[0044] (1) Batching: Fe, Si, Cu and FeB alloy raw materials with a mass percentage purity of not less than 99% are prepared according to the atomic percentage formula Fe 73.3 Si 12 B 13 Cu 1.7 Weigh and prepare alloy raw materials;

[0045] (2) Melting the master alloy: The alloy raw materials prepared in step 1 are placed in the melting furnace, the vacuum is drawn to less than 1.0 Pa, argon gas is introduced to 0.05 MPa, the melting temperature is 1400℃, and after melting is uniform, the temperature is held for 5 minutes to ensure the chemical homogeneity of the alloy ingot and form the master alloy.

[0046] (3) Preparation of iron-based nanocrystalline soft magnetic alloy powder: The master alloy obtained in step 2 is placed in a gas atomization device with a nozzle diameter of 1.0 mm. The master alloy is heated to 1500℃, completely melted, and held at that temperature for 10 seconds before atomization. The spray pressure is 0.2 MPa and the atomizing gas pressure is 8 MPa to obtain iron-based nanocrystalline soft magnetic alloy powder.

[0047] (4) Coating: 3% epoxy resin by mass of magnetic powder is used as a binder and dissolved in acetone. Take an appropriate amount of nanocrystalline alloy powder obtained in step 3, add it to acetone and disperse it evenly by ultrasonic dispersion. After the acetone is completely evaporated, nanocrystalline alloy coated powder is obtained and placed in an oven and dried at 60-80℃ for 1 hour.

[0048] (5) Ring making: The nanocrystalline alloy coated powder obtained in step 4 is pressed into a magnetic ring with an inner diameter of 12.7 mm, an outer diameter of 20.3 mm, and a height of 2.3 mm using a pressure of 1800 MPa, and then subjected to vacuum heat treatment at 480℃ for 60 min to obtain an iron-based nanocrystalline soft magnetic composite material.

[0049] The iron-based nanocrystalline soft magnetic alloy powder and soft magnetic composite material prepared above were subjected to the following tests:

[0050] (1) The obtained iron-based nanocrystalline soft magnetic alloy powder was sieved to obtain an average particle size D. 50 The morphology of the iron-based nanocrystalline soft magnetic alloy powder, with a particle size of 13-15 μm, was observed using scanning electron microscopy (SEM). The morphology of the obtained iron-based nanocrystalline soft magnetic alloy powder is shown in the figure below. Figure 1 As shown in the figure, the prepared iron-based nanocrystalline soft magnetic alloy powder has good sphericity.

[0051] (2) The structure of the iron-based nanocrystalline soft magnetic alloy powder was analyzed by XRD. The results are as follows: Figure 2 As shown, the XRD pattern contains three sharp diffraction peaks and diffuse scattering peaks corresponding to the α-Fe phase, indicating that the powder structure is a two-phase composite structure in which the α-Fe nanocrystalline phase is distributed in an amorphous matrix.

[0052] (3) The microstructure of the iron-based nanocrystalline soft magnetic alloy powder was analyzed by TEM. The TEM analysis results are as follows: Figure 3 As shown in the figure, the powder structure is a two-phase composite structure in which the crystalline phase is uniformly distributed in an amorphous matrix, with an average crystalline phase size of 15.1 nm. Selected area electron diffraction (SED) indicates that the generated crystalline phase is the α-Fe phase.

[0053] (4) The magnetic properties of the iron-based nanocrystalline soft magnetic alloy powder were analyzed using VSM, and the results are as follows: Figure 4 As shown, the measured M s and H c Listed in Table 1. From the VSM curves, it can be seen that the VSM curves of the iron-based nanocrystalline soft magnetic alloy powder are narrow, indicating very low coercivity, thus demonstrating typical soft magnetic characteristics. Its M... s and H c The values ​​were 156.2 emu / g and 6.3 Oe, respectively.

[0054] (5) Figure 5 As shown, the iron-based nanocrystalline soft magnetic alloy powder provided in this embodiment of the invention exhibits excellent soft magnetic properties, with a strength as low as 3650 mW / cm². 3 (50mT / 1MHz) loss, while Fe 50 Ni 50 (Composition formula by mass percentage, the same below) The loss of the soft magnetic composite material is 7885 mW / cm. 3 (50mT / 1MHz).

[0055] (6) Figure 6As shown, the iron-based nanocrystalline soft magnetic alloy powder provided in this embodiment of the invention exhibits excellent high-frequency stability within 10MHz, with a permeability μ e 43.1, Fe 50 Ni 50 The permeability of the soft magnetic composite material is 42.5, and its frequency stability is poor.

[0056] Examples 2-9

[0057] The preparation and performance testing methods and steps for iron-based nanocrystalline soft magnetic alloy powders and soft magnetic composite materials are as follows:

[0058] (1) Batching: Weigh and prepare alloy raw materials according to the atomic percentage formula in Table 1, with the raw materials having a purity of not less than 99% by mass percentage.

[0059] (2) Melting the master alloy: Same as step 2 in Example 1;

[0060] (3) Preparation of iron-based nanocrystalline soft magnetic alloy powder: Same as step 3 in Example 1;

[0061] (4) Coating: Same as step 4 in Example 1;

[0062] (5) Ring making: Same as step 5 in Example 1.

[0063] The structural and magnetic property tests performed on the iron-based nanocrystalline soft magnetic alloy powder and soft magnetic composite material prepared above were the same as those in Example 1:

[0064] Comparative Example 1

[0065] This comparison is for commercial Fe. 50 Ni 50 Alloy powder has excellent overall magnetic properties, but it suffers from high losses and high costs.

[0066] Comparative Example 2

[0067] This comparison is for commercial Fe. 73.5 Si 13.5 B9Nb3Cu1 nanocrystalline powder has excellent overall magnetic properties, but its Ms is relatively low.

[0068] Comparative Example 3

[0069] This comparative example is from patent CN101263240B, which has poor amorphous formation ability and contains a large amount of non-soft magnetic Fe-B phase in the atomized powder, resulting in H in the powder. c The performance of soft magnetic composite materials is relatively poor.

[0070] Comparative Example 4

[0071] This comparative example is from patent CN101641455B, which has poor amorphous formation ability and contains a large amount of non-soft magnetic Fe-B phase in the atomized powder, resulting in H in the powder. c The performance of soft magnetic composite materials is relatively poor.

[0072] Comparative Example 5

[0073] This comparative example is from patent CN101663410A, which has poor amorphous formation ability and contains a large amount of non-soft magnetic Fe-B phase in the atomized powder, resulting in H in the powder. c The performance of soft magnetic composite materials is relatively poor.

[0074] Comparative Example 6

[0075] The comparative example is from the literature Journal of Applied Physics 109,07A302 (2011). It has poor amorphous forming ability, and the atomized powder contains a large amount of non-soft magnetic Fe-B phase, leading to H... c The performance of soft magnetic composite materials is relatively poor.

[0076] Table 1: Average size (D) and saturation magnetization (M) of the α-Fe phase in the alloys of Examples 1-9 and Comparative Examples 1-6 s ) and coercivity (H c ) and the loss (P) of soft magnetic composite materials at 50mT / 1MHz cv ) and permeability (μ) at 100 kHz e )

[0077]

[0078]

[0079] Examples 10-29 illustrate the preparation and performance testing process of soft magnetic composite materials prepared by compounding iron-based nanocrystalline powder and alloyed soft magnetic powder provided by the present invention.

[0080] Example 10

[0081] (1) Powder compounding: Fe 73.3 Si 12 B 13 Cu 1.7 Nanocrystalline powder and carbonyl iron powder are compounded and mixed evenly in a mass ratio of 4:6 to obtain a mixed powder, wherein Fe 73.3 Si 12 B 13 Cu 1.7 D of nanocrystalline powder 50 The D of carbonyl iron powder is 13-15 μm. 50 It is 4-5μm.

[0082] (2) Coating: 3% epoxy resin by mass of magnetic powder is dissolved in acetone. The compounded powder is added to acetone and dispersed evenly by ultrasonic dispersion. After the acetone is completely evaporated, nanocrystalline alloy coated powder is obtained and vacuum dried at 60-80℃ for 1 hour.

[0083] (3) Ring making: The coating powder obtained in step (2) is pressed into a magnetic ring with an inner diameter of 12.7 mm, an outer diameter of 20.3 mm, and a height of 2.3 mm using a pressure of 1800 MPa, and then subjected to vacuum heat treatment at 480℃ for 60 min to obtain a soft magnetic composite material.

[0084] The soft magnetic composite material prepared above was subjected to the following tests:

[0085] (1) The soft magnetic composite material was characterized using an AC BH instrument, and its loss variation curve with test frequency is shown in the figure. Figure 5 The soft magnetic composite material, heat-treated at 480℃, exhibits excellent soft magnetic properties, with a loss of 2530 mW / cm² under 50 mT / 1 MHz conditions. 3 .

[0086] (2) The soft magnetic composite material was characterized using an impedance analyzer, and its permeability versus frequency curve is shown in the figure. Figure 6 The soft magnetic composite material heat-treated at 480℃ exhibits excellent high-frequency stability within 10MHz, with a permeability μ e It is 53.4.

[0087] Examples 11-29

[0088] (1) Powder compounding: The types and proportions of powders are as shown in Table 2, and the process steps are the same as step 1 in Example 10.

[0089] (2) Coating: The same as step 2 in Example 10.

[0090] (3) Ring making: The same as step 3 in Example 10.

[0091] The magnetic properties of the soft magnetic composite material were characterized in the same way as in Example 10, and the measured data are listed in Table 2.

[0092] Table 2. Types of magnetic powder, blending ratios, and losses (P0) of soft magnetic composite materials in Examples 10-29 at 50 mT / 1 MHz. cv ) and permeability (μ) at 100 kHz e )

[0093]

[0094]

[0095] While the disclosure is as stated above, its scope of protection is not limited thereto. Those skilled in the art can make various changes and modifications without departing from the spirit and scope of this disclosure, and all such changes and modifications will fall within the protection scope of this invention.

Claims

1. An iron-based nanocrystalline soft magnetic alloy powder, characterized in that, The iron-based nanocrystalline soft magnetic alloy powder was prepared directly by atomization, and its atomic percentage molecular formula was Fe. a B b C c Si d Cu e M m Q q Z z X x Where M is at least one of Co and Ni, Q is at least one of a pre-transition element, a half-metal element, a rare earth element, and Al, wherein the pre-transition element is Ti, V, Cr, Mn, Y, Zr, Nb, Mo, Hf, Ta, or W, the half-metal element is Ge, As, or Sb, Z is at least one of Au, Ag, and a platinum group metal, X is at least one of O, N, S, and a halogen element, 70≤a+m≤75, 8≤b≤18, 0≤c≤5, 10≤d≤15, 0≤m<10, 1.6≤e≤2.5, 0≤q≤1, 0≤z≤1, 0≤x≤0.2, and 22≤b+c+d≤30, a+b+c+d+e+m+q+z+x=100; The average size of the α-Fe grains in the iron-based nanocrystalline soft magnetic alloy powder is 10-18 nm, and the α-Fe grains are spherical or near-spherical in shape. The saturation magnetization and coercivity are 150.0-170.0 emu / g and 3.0-7.0 Oe, respectively.

2. The iron-based nanocrystalline soft magnetic alloy powder according to claim 1, characterized in that, The sum of the atomic percentages of Fe and M elements is 72 ≤ a + m ≤ 74, and the atomic percentage of M element is 0 ≤ m ≤ 5.

3. The iron-based nanocrystalline soft magnetic alloy powder according to claim 1, characterized in that, The atomic percentage of element B is 10≤b≤15, the atomic percentage of Si is 11≤d≤14, and the atomic percentage of C is 0≤c≤3, with 24≤b+c+d+e≤28.

4. The iron-based nanocrystalline soft magnetic alloy powder according to claim 1, characterized in that, The atomic percentage of element Q is 0 ≤ q ≤ 0.

5.

5. The iron-based nanocrystalline soft magnetic alloy powder according to claim 1, characterized in that, The atomic percentage of element Z is 0 ≤ z ≤ 0.

5.

6. The iron-based nanocrystalline soft magnetic alloy powder according to claim 1, characterized in that, The atomic percentage of element X is 0 ≤ x ≤ 0.

1.

7. A soft magnetic composite material, characterized in that, The mixture comprises a mixed powder and a binder coating the mixed powder, wherein the mixed powder comprises iron-based nanocrystalline soft magnetic alloy powder and alloyed soft magnetic powder as described in any one of claims 1-6; wherein the alloyed soft magnetic powder is selected from at least one of carbonyl iron powder, iron-silicon powder, iron-silicon-chromium powder, iron-silicon-aluminum powder, and iron-nickel powder, and accounts for 0-95% of the total mass of the mixed powder; the binder is selected from at least one of epoxy resin, phenolic resin, polyamide resin, and organosilicon resin, and accounts for 1-5% of the total mass of the mixed powder.

8. A method for preparing a soft magnetic composite material according to claim 7, comprising: (1) The iron-based nanocrystalline soft magnetic powder is prepared according to the atomic percentage composition formula of any one of claims 1-6, and the mixture is melted evenly to form a master alloy; (2) The master alloy was prepared into iron-based nanocrystalline soft magnetic powder by atomization; (3) After mixing the iron-based nanocrystalline soft magnetic powder obtained in step (2) with the alloy soft magnetic powder, a binder is added for coating to obtain the coated mixed soft magnetic powder; (4) The coated mixed soft magnetic powder obtained in step (3) is pressed into a soft magnetic composite material and then subjected to heat treatment.

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