Amorphous nanocrystalline strip and preparation method thereof

Abstract

The invention belongs to the technical field of magnetic functional materials, and particularly relates to an amorphous nanocrystalline strip and a preparation method thereof. The amorphous nanocrystalline strip is prepared from the following raw materials in percentage by mass: 5.6 to 6.5 weight percent of Nb, 9.5 to 10.5 weight percent of Si, 1 to 2 weight percent of B, 0.5 to 1 weight percent of Cu, 0.1 to 0.2 weight percent of Co, 0.05 to 0.1 weight percent of Zr, 0.4 to 1.5 weight percent of rare earth element, 0.5 to 1.0 weight percent of high-entropy oxide and the balance of Fe; the high-entropy oxide is prepared by the following preparation process: adding ferric chloride, cobalt chloride, nickel chloride, manganese chloride and scandium chloride into diethylene glycol, and heating, stirring, centrifuging, washing, drying and calcining under a closed condition to obtain the high-entropy oxide. The amorphous nanocrystalline strip prepared by the preparation method disclosed by the invention is relatively high in magnetic conductivity and relatively small in coercive force, and has relatively high stability in a temperature range of-40 DEG C to + 150 DEG C.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of magnetic functional materials, and particularly relates to an amorphous nanocrystalline strip and a preparation method thereof. BACKGROUND

[0002] With the rapid rise of AI algorithm, 5G communication, new energy vehicles and electronic product industries, electronic components begin to show a trend of miniaturization and high frequency, and the demand for inductance market is increasing year by year. As the magnetic core material of inductor, the performance of soft magnetic material plays a decisive role in the energy conversion frequency and system power density of electronic devices, so it is required to have high frequency low loss and high saturation magnetic induction density. Soft magnetic materials mainly include silicon steel, ferrite, permalloy, iron-based and cobalt-based amorphous nanocrystalline, and have wide application in electronic devices such as transformers, sensors and controllers.

[0003] Amorphous alloy is formed by continuous transformation of metal melt under extremely high cooling rate, and the internal atoms are arranged in a long-range disordered and short-range ordered state, which does not have grain structure similar to that of crystalline alloy, so that there are no defects in the alloy that hinder the movement of domain walls. And the short-range ordered atomic arrangement makes the exchange interaction more likely to occur between adjacent atoms, promoting the coupling of electrons, so that the ferromagnetic amorphous alloy has the characteristics of high magnetic permeability and low coercivity. Nanocrystalline is a complex alloy with nanoscale crystalline phase uniformly generated on the amorphous matrix. Compared with pure amorphous phase, iron-based nanocrystalline can realize high saturation magnetization and low coercivity by precise control of grain size and suppression of magnetic anisotropy, with outstanding comprehensive advantages. At present, iron-based amorphous nanocrystalline strip has developed into a core soft magnetic material, but the strip still has problems such as high brittleness, poor temperature adaptability and low yield, which still need to be improved by composition design and preparation process improvement to obtain a strip with excellent comprehensive performance. SUMMARY

[0004] The first object of the present application is to provide an amorphous nanocrystalline strip with high magnetic permeability, small coercivity and high stability at-40℃ to +150℃.

[0005] The second object of the present application is to provide a preparation method of the amorphous nanocrystalline strip.

[0006] An amorphous nanocrystalline strip is composed of the following raw materials in mass percentage: Nb 5.6-6.5 wt%, Si 9.5-10.5 wt%, B 1-2 wt%, Cu 0.5-1 wt%, Co 0.1-0.2 wt%, Zr 0.05-0.1 wt%, rare earth elements 0.4-1.5 wt%, high-entropy oxide 0.5-1.0 wt%, and the balance is Fe. The high-entropy oxide is prepared by the following preparation process: Iron chloride, cobalt chloride, nickel chloride, manganese chloride and scandium chloride are added into diethylene glycol, heated and stirred under a closed condition, and high-entropy oxide is obtained after centrifugation, washing, drying and calcination.

[0007] Further, the molar ratio of the iron chloride, cobalt chloride, nickel chloride, manganese chloride and scandium chloride is (1-4):(1-4):(1-4):(1-4):(1-4).

[0008] Further, the temperature of the heating and stirring is 200-240 ℃, and the time is 20-50 min; the temperature of the calcination is 500-700 ℃, and the time is 2-5 h.

[0009] Further, the rare earth element is composed of lanthanum and lutetium in a mass ratio of (1-3):1.

[0010] The preparation method of the amorphous nanocrystalline strip material above comprises the following steps: (1) under an argon atmosphere with a vacuum degree <10 -2 Pa, the raw materials are heated and stirred and mixed, then poured into a mold to cool to obtain a master alloy ingot; (2) the master alloy ingot is broken, washed, melted and then an amorphous strip material is obtained by single-roll tape casting; (3) the amorphous strip material is sequentially annealed and crystallized, and then cooled to obtain an amorphous nanocrystalline strip material.

[0011] Further, the specific process of the heating and stirring in step (1) is: first heat at 800-1000 ℃ for 2-5 min, and then stir at 1500-1600 ℃ for 10-20 min.

[0012] Further, the roller speed in the single-roll tape casting process in step (2) is 40-50 m / s.

[0013] Further, the specific steps of the annealing and crystallization in step (3) are: first heat at a rate of 3-5 ℃ / min to 100-280 ℃ under a transverse magnetic field of 5-20 kA / m, and then heat at a rate of 7-10 ℃ / min to 350-480 ℃, and crystallize for 30-50 min.

[0014] Further, the cooling rate of the cooling in step (3) is 50-80 ℃ / min.

[0015] To achieve the above purpose, the technical scheme adopted by the present application is: The beneficial technical effects of the present application are: 1. This invention improves the soft magnetic properties of amorphous nanocrystalline ribbons by increasing the Nb content in the amorphous nanocrystalline alloy, optimizing the Zr and Co ratio, and adding the light rare earth element La and the heavy rare earth element Lu. Nb, a pre-transition element with a medium atomic size, can form a large atomic size difference with Fe, which is beneficial to improving the amorphous formation ability of Fe-based alloys and enhancing the stability of the ribbon. Co and Zr are similar elements to Fe and Nb, respectively, which can increase the disorder inside the alloy, complicate the competing crystal phases, improve the thermal stability of the alloy, and form a segregation effect at the grain boundaries, inhibiting grain growth during heat treatment. The combined addition of rare earth elements La and Lu can replace part of Zr and Co, improve the thermal stability of the amorphous alloy, hinder grain boundary movement, inhibit grain growth, and at the same time, rare earth elements can adsorb impurity elements, playing a refining and impurity removal role, which is beneficial to optimizing the microstructure of the ribbon and improving the soft magnetic properties.

[0016] 2. This invention further incorporates nano-high-entropy oxides into amorphous nanocrystalline ribbons, which enhances the structural and thermal stability of the ribbons. High-entropy oxides possess excellent mechanical properties and thermal stability; as additives, they improve the temperature adaptability of the ribbons and mitigate their brittleness. Simultaneously, the nanoscale oxide particles provide nucleation sites for the nanocrystalline phase, promoting the nucleation and uniform distribution of the nanocrystalline soft magnetic phase. This facilitates the acquisition of fine-sized and uniform nanocrystalline soft magnetic phases, thereby improving the soft magnetic properties of the ribbons.

[0017] 3. The present invention employs segmented heat treatment technology, which can improve the magnetic permeability and reduce the coercivity of amorphous nanocrystalline ribbons. First, the ribbon is subjected to stress-relief annealing in the low-temperature region to eliminate the pinning effect of internal stress on magnetic domains. Then, crystallization treatment is performed in the medium-temperature region to form small and uniformly distributed nanocrystalline phases, thereby enabling the ribbon to obtain high magnetic permeability and low coercivity. Attached Figure Description

[0018] Figure 1 This is a scanning electron microscope image of the high-entropy oxide prepared in Example 1 of the present invention; Figure 2 The frequency characteristic curves of the magnetic permeability of the amorphous nanocrystalline ribbons prepared in Examples 1-3 and Comparative Examples 1-3 are shown. Detailed Implementation

[0019] The following is a further detailed description of the present invention in conjunction with specific preferred embodiments, and it should not be construed that the specific implementation of the present invention is limited to these descriptions. For those skilled in the art, various simple deductions or substitutions can be made without departing from the concept of the present invention, and all such modifications and substitutions should be considered within the scope of protection of the present invention. Specific conditions not specified in the embodiments are performed according to conventional conditions or conditions recommended by the manufacturer. Unless otherwise specified, all reagents or instruments used are conventional products obtained through commercial channels.

[0020] (I) Implementation Examples Example 1 Example 1 provides an amorphous nanocrystalline ribbon composed of the following raw materials by mass percentage: Nb 6.2 wt%, Si 10.1 wt%, B 1.5 wt%, Cu 0.8 wt%, Co 0.1 wt%, Zr 0.08 wt%, rare earth elements 0.9 wt%, high entropy oxides 0.8 wt%, with the balance being Fe; wherein the rare earth elements are composed of lanthanum and lutetium in a mass ratio of 2:1.

[0021] The high-entropy oxide is prepared by the following process: According to the following ratio of ferric chloride, cobalt chloride, nickel chloride, manganese chloride, scandium chloride, and diethylene glycol: 1 mol: 1 mol: 1 mol: 1 mol: 1 mol: 70 L, ferric chloride, cobalt chloride, nickel chloride, manganese chloride, and scandium chloride were added to diethylene glycol and stirred until dissolved. The solution was then transferred to a reaction vessel and stirred under sealed conditions at 220 °C for 30 min. After centrifugation, washing, and drying, the precursor was obtained. The precursor was calcined at 600 °C for 3 h to obtain a high-entropy oxide. The scanning electron microscope image of this high-entropy oxide is shown below. Figure 1 As shown.

[0022] This embodiment also provides a method for preparing the above-mentioned amorphous nanocrystalline ribbon, the specific steps of which are as follows: (1) After mixing the raw materials evenly according to the above mass percentages, transfer them into the melting furnace and evacuate to a vacuum of 10 under an argon atmosphere. -2 Pa, first heat to 900 ℃ and hold for 3 min, then heat to 1550 ℃ and stir electromagnetically for 15 min, then pour into a water-cooled mold, and obtain the master alloy ingot after cooling; (2) The above-mentioned master alloy ingot is crushed and cleaned, and then placed in a quartz tube for induction melting. Amorphous ribbon is produced by single-roller spinning at a roller speed of 45 m / s. (3) The above amorphous ribbon was heated to 190°C at a heating rate of 4°C / min under a transverse magnetic field of 15 kA / m, held for annealing for 1 h, then heated to 400°C at a heating rate of 8°C / min, held for crystallization for 40 min, and finally cooled rapidly at a cooling rate of 60°C / min to obtain the amorphous nanocrystalline ribbon.

[0023] Example 2 Example 2 provides an amorphous nanocrystalline ribbon composed of the following raw materials by mass percentage: Nb 5.6 wt%, Si 9.5 wt%, B 1 wt%, Cu 0.5 wt%, Co 0.1 wt%, Zr 0.05 wt%, rare earth elements 0.4 wt%, high entropy oxides 0.5 wt%, with the balance being Fe; wherein the rare earth elements are composed of lanthanum and lutetium in a mass ratio of 1:1.

[0024] The high-entropy oxide is prepared by the following process: According to the ratio of ferric chloride, cobalt chloride, nickel chloride, manganese chloride, scandium chloride, and diethylene glycol (1 mol: 1 mol: 4 mol: 4 mol: 4 mol: 100 L), ferric chloride, cobalt chloride, nickel chloride, manganese chloride, and scandium chloride were added to diethylene glycol and stirred until dissolved. The solution was then transferred to a reaction vessel and stirred under closed conditions at 200 °C for 20 min. After centrifugation, washing, and drying, the precursor was obtained. The precursor was then calcined at 500 °C for 2 h to obtain the high-entropy oxide.

[0025] This embodiment also provides a method for preparing the above-mentioned amorphous nanocrystalline ribbon, the specific steps of which are as follows: (1) After mixing the raw materials evenly according to the above mass percentages, transfer them into the melting furnace and evacuate to a vacuum of 10 under an argon atmosphere. -2 Pa, first heat to 800 ℃ and hold for 2 min, then heat to 1500 ℃ and stir electromagnetically for 10 min, then pour into a water-cooled mold, and obtain the master alloy ingot after cooling; (2) The above-mentioned master alloy ingot is crushed and cleaned, and then placed in a quartz tube for induction melting. Amorphous ribbon is produced by single-roller spinning at a roller speed of 40 m / s. (3) The above amorphous ribbon was heated to 100°C at a heating rate of 3°C / min under a transverse magnetic field of 5 kA / m, and held for annealing for 1 h. Then it was heated to 350°C at a heating rate of 7°C / min and held for crystallization for 30 min. Finally, it was rapidly cooled at a cooling rate of 50°C / min to obtain the amorphous nanocrystalline ribbon.

[0026] Example 3 Example 3 provides an amorphous nanocrystalline ribbon composed of the following raw materials by mass percentage: Nb 6.5 wt%, Si 10.5 wt%, B 2 wt%, Cu 1 wt%, Co 0.2 wt%, Zr 0.1 wt%, rare earth elements 1.5 wt%, high entropy oxides 1.0 wt%, with the balance being Fe; wherein the rare earth elements are composed of lanthanum and lutetium in a mass ratio of 3:1.

[0027] The high-entropy oxide is prepared by the following process: According to the ratio of ferric chloride, cobalt chloride, nickel chloride, manganese chloride, scandium chloride, and diethylene glycol, 4 mol: 4 mol: 4 mol: 1 mol: 1 mol: 160 L, ferric chloride, cobalt chloride, nickel chloride, manganese chloride, and scandium chloride were added to diethylene glycol and stirred until dissolved. The solution was then transferred to a reaction vessel and stirred under closed conditions at 240 °C for 50 min. After centrifugation, washing, and drying, the precursor was obtained. The precursor was then calcined at 700 °C for 5 h to obtain the high-entropy oxide.

[0028] This embodiment also provides a method for preparing the above-mentioned amorphous nanocrystalline ribbon, the specific steps of which are as follows: (1) After mixing the raw materials evenly according to the above mass percentages, transfer them into the melting furnace and evacuate to a vacuum of 10 under an argon atmosphere. -3 Pa, first heat to 1000 ℃ and hold for 5 min, then heat to 1600 ℃ and stir electromagnetically for 20 min, then pour into a water-cooled mold, and obtain the master alloy ingot after cooling; (2) The above-mentioned master alloy ingot is crushed and cleaned, and then placed in a quartz tube for induction melting. Then, the amorphous ribbon is produced by single-roller spinning at a roller speed of 50 m / s. (3) The above amorphous ribbon was heated to 280°C at a heating rate of 5°C / min under a transverse magnetic field of 20 kA / m, and held for annealing for 2 h. Then it was heated to 480°C at a heating rate of 10°C / min and held for crystallization for 50 min. Finally, it was rapidly cooled at a cooling rate of 80°C / min to obtain the amorphous nanocrystalline ribbon.

[0029] (ii) Comparative Example Comparative Example 1 Comparative Example 1 is basically the same as Example 1, except that lutetium in the rare earth element is omitted.

[0030] Comparative Example 2 Comparative Example 2 is basically the same as Example 1, except that the high-entropy oxide is omitted.

[0031] Comparative Example 3 Comparative Example 3 is basically the same as Example 1, except that the high-entropy oxide is replaced with scandium oxide.

[0032] (III) Test Examples The nanocrystalline ribbons prepared in Examples 1-3 and Comparative Examples 1-3 were subjected to performance tests.

[0033] Permeability testing: The permeability of Examples 1-3 and Comparative Examples 1-3 was measured using an impedance analyzer at room temperature and frequencies ranging from 1 to 1000 kHz. The results are shown in [reference needed]. Figure 2 .

[0034] Coercivity: The coercivity of Examples 1-3 and Comparative Examples 1-3 was measured using a BH analyzer at room temperature. The results are shown in Table 1.

[0035] Rate of change of magnetic permeability at high and low temperatures: The rate of change of magnetic permeability of nanocrystalline ribbons at -40℃ to +150℃ was measured compared with that of nanocrystalline ribbons at room temperature. The results are shown in Table 1.

[0036] Table 1 Test results of nanocrystalline ribbon From Table 1 and Figure 2 It can be seen that the amorphous nanocrystalline ribbons prepared in Examples 1-3 of the present invention have high magnetic permeability, low coercivity, and high stability within the range of -40℃ to +150℃.

[0037] Compared to Example 1, Comparative Example 1 replaced the rare earth elements in Example 1 with lanthanum, resulting in a significant decrease in soft magnetic properties and a slight decrease in stability. This indicates that by increasing the Nb content of the amorphous nanocrystalline alloy, optimizing the ratio of Zr and Co elements, and adding light rare earth La and heavy rare earth Lu, the soft magnetic properties of the amorphous nanocrystalline ribbon can be improved. Specific analysis reveals that Nb, being a pre-transition element with a medium atomic size, can form a large atomic size difference with Fe, which is beneficial for improving the amorphous formation ability of Fe-based alloys and enhancing the stability of the strip. Co and Zr are similar elements to Fe and Nb, respectively, which can increase the disorder within the alloy, complicate the competing crystal phases, improve the thermal stability of the alloy, and form a segregation effect at the grain boundaries, inhibiting grain growth during heat treatment. The combined addition of rare earth elements La and Lu can replace part of Zr and Co, improve the thermal stability of the amorphous alloy, hinder grain boundary movement, and inhibit grain growth. At the same time, rare earth elements can also adsorb impurity elements, achieving a refining and impurity removal effect, which is beneficial for optimizing the microstructure of the strip and improving soft magnetic properties.

[0038] Compared to Example 1, Comparative Example 2 omitted the high-entropy oxide, and Comparative Example 3 replaced the high-entropy oxide with scandium oxide. The stability of Comparative Examples 2 and 3 decreased significantly, and their soft magnetic properties were also affected. This indicates that adding nano-high-entropy oxides to amorphous nanocrystalline ribbons can improve the structural and thermal stability of the ribbon. Specific analysis shows that high-entropy oxides possess good mechanical properties and thermal stability. As an additive, they can improve the temperature adaptability of the ribbon and reduce its brittleness. Simultaneously, nanoscale oxide particles can provide nucleation sites for the nanocrystalline phase, promoting the nucleation and uniform distribution of the nanocrystalline soft magnetic phase, which is beneficial for obtaining fine and uniform nanocrystalline soft magnetic phases and improving the soft magnetic properties of the ribbon.

[0039] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them. The basic principles and main features of the present invention have been described above with specific implementation schemes. Based on the present invention, some modifications or substitutions can be made, but these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of protection claimed by the present invention.

Claims

1. An amorphous nanocrystalline ribbon, characterized in that, The amorphous nanocrystalline ribbon is composed of the following raw materials in the indicated mass percentages: Nb 5.6-6.5 wt%, Si 9.5-10.5 wt%, B 1-2 wt%, Cu 0.5-1 wt%, Co 0.1-0.2 wt%, Zr 0.05-0.1 wt%, rare earth elements 0.4-1.5 wt%, high entropy oxides 0.5-1.0 wt%, with the balance being Fe; The high-entropy oxide is prepared by the following process: Ferric chloride, cobalt chloride, nickel chloride, manganese chloride, and scandium chloride were added to diethylene glycol, heated and stirred under sealed conditions, and then centrifuged, washed, dried, and calcined to obtain high-entropy oxides.

2. The amorphous nanocrystalline ribbon according to claim 1, characterized in that, The molar ratio of ferric chloride, cobalt chloride, nickel chloride, manganese chloride and scandium chloride is (1-4):(1-4):(1-4):(1-4):(1-4):(1-4).

3. The amorphous nanocrystalline ribbon according to claim 1, characterized in that, The heating and stirring temperature is 200-240 ℃, and the time is 20-50 min; the calcination temperature is 500-700 ℃, and the time is 2-5 h.

4. The amorphous nanocrystalline ribbon according to claim 1, characterized in that, The rare earth elements are composed of lanthanum and lutetium in a mass ratio of (1-3):

1.

5. A method for preparing the amorphous nanocrystalline ribbon according to any one of claims 1-4, characterized in that, Includes the following steps: (1) When the vacuum degree is <10 -2 Under an argon atmosphere of Pa, the raw materials are heated and stirred together, then poured into a mold and cooled to obtain a master alloy ingot; (2) The master alloy ingot is crushed, cleaned, melted, and then amorphous strip is obtained by single-roller spinning; (3) The amorphous ribbon is annealed and crystallized in sequence, and then cooled to obtain an amorphous nanocrystalline ribbon.

6. The method for preparing amorphous nanocrystalline ribbons according to claim 5, characterized in that, The specific process of heating and stirring in step (1) is as follows: first, keep warm at 800-1000 ℃ for 2-5 min, and then raise the temperature to 1500-1600 ℃ and stir for 10-20 min.

7. The method for preparing amorphous nanocrystalline ribbons according to claim 5, characterized in that, The roller speed in the single-roller belt-spinning process described in step (2) is 40-50 m / s.

8. The method for preparing amorphous nanocrystalline ribbons according to claim 5, characterized in that, The specific steps of annealing and crystallization in step (3) are as follows: Under a transverse magnetic field of 5-20 kA / m, first heat up to 100-280 ℃ at a heating rate of 3-5 ℃ / min, hold for annealing for 1-2 h, and then heat up to 350-480 ℃ at a heating rate of 7-10 ℃ / min, hold for crystallization for 30-50 min.

9. The method for preparing amorphous nanocrystalline ribbons according to claim 5, characterized in that, The cooling rate described in step (3) is 50-80 °C / min.

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