Fe-Nb-B-Y amorphous alloy, and preparation method and application thereof

Abstract

This invention belongs to the field of metallic materials technology, and particularly relates to an Fe-Nb-B-Y amorphous alloy, its preparation method, and its applications. The alloy has the following atomic percentage expression: (Fe 85 B 14.7 Nb 0.3 ) 100‑x Y x Where 0.2≤x≤0.3. This Fe-Nb-B-Y amorphous alloy maintains high glass-forming ability while also possessing low coercivity and high saturation magnetization.

Description

Technical Field

[0001] This invention belongs to the field of metallic materials technology, and particularly relates to an Fe-Nb-BY amorphous alloy, its preparation method, and its application. Background Technology

[0002] Traditional Fe-Nb-B ternary amorphous alloys possess high saturation magnetization and low coercivity, making them widely used in power electronics, new energy, and other fields. However, this ternary system faces core technological bottlenecks: firstly, insufficient ground-forming ability (GFA) and high critical cooling rate requirements, limiting its fabrication to micron-sized amorphous ribbons; secondly, poor thermal stability, a narrow supercooled liquid phase region, and a low crystallization temperature, making it prone to crystallization failure during high-temperature service. Furthermore, it is often difficult to balance the soft magnetic properties with the GFA and thermal stability of the material. These contradictions restrict its engineering applications under more complex or harsher conditions, affecting subsequent processing and service reliability.

[0003] Alloying is a core method for controlling the microstructure and macroscopic properties of amorphous alloys, effectively improving strip forming ability and thermal stability. However, its dilution effect on magnetic properties needs to be carefully weighed. Existing modification schemes mostly focus on the addition of transition elements. For example, in the Fe-Nb-B system, Chinese invention patent CN112002513A achieved good forming ability and soft magnetic properties by adding the transition elements Nb and Y. However, on the one hand, it cannot break through the system bottleneck from the core thermodynamic and structural essence of amorphous formation; on the other hand, the large Nb content makes the cost of industrial production increase sharply.

[0004] Therefore, adding rare earth element Y to Fe-Nb-B alloys with low Nb content can give them excellent soft magnetic properties and good amorphous forming ability, which is expected to meet the industrial demand for low-cost, high-performance iron-based amorphous soft magnetic alloys for electronic devices. Summary of the Invention

[0005] This invention synergistically modifies the Fe-Nb-B system by precisely adding rare-earth element Y, focusing on two core regulatory dimensions of amorphous formation: atomic size mismatch and mixing enthalpy between components. Furthermore, reducing the Nb content to 0.3% in the conventional Fe-Nb-B base system significantly lowers production costs and solves the aforementioned technical challenges. Simultaneously, the iron-based amorphous alloy composition of this application, through the overall replacement of the base system with Y element, minimizes the loss of ferromagnetic elements, achieving higher saturation magnetization and lower coercivity, as well as better formation ability and Δ... T x =86 K, a wider annealing window.

[0006] In a first aspect, the present invention provides an Fe-Nb-BY amorphous alloy having the following atomic percentage expression: (Fe 85 Nb 0.3 B 14.7 ) 100-x Y x Where 0.2≤x≤0.3; The saturation magnetization Ms ≥ 1.43T and the coercivity Hc ≤ 27 A / m of the amorphous alloy.

[0007] Preferably, the atomic percentage of the Fe-Nb-BY amorphous alloy is expressed as (Fe 85 Nb 0.3 B 14.7 ) 99.8 Y 0.2 .

[0008] Preferably, the atomic percentage of the Fe-Nb-BY amorphous alloy is expressed as (Fe 85 Nb 0.3 B 14.7 ) 99.7 Y 0.3 .

[0009] Furthermore, the aforementioned Fe-Nb-BY amorphous alloy exhibits a completely amorphous structure within a width of 1-2 mm and a thickness of 20-25 μm. The Fe-Nb-BY amorphous alloy of this application, even at a maximum forming size of 2 mm width and 25 μm thickness, shows no obvious crystallization peaks upon XRD analysis, indicating a completely amorphous structure. In contrast, traditional Fe-Nb-B ternary amorphous alloys, under the same preparation process, can only achieve complete amorphization within a width of 1 mm and a thickness of 15 μm; beyond this size, a crystalline phase appears. This demonstrates that the glass-forming ability of the alloy in this application is significantly superior to existing technologies. The X-ray diffraction pattern of the Fe-Nb-BY amorphous alloy shows diffuse scattering peaks in the range of 2θ from 32.5° to 55°, with a full width at half maximum (FWHM) of 0.35 to 0.51, and no sharp crystallization peaks, indicating that it possesses a completely amorphous structure.

[0010] Secondly, the present invention provides a method for preparing Fe-Nb-BY amorphous alloy, comprising the following steps: S1: Weigh the elemental metal (purity ≥ 99.9%) according to the atomic percentage of the Fe-Nb-BY amorphous alloy, clean it with petroleum ether and anhydrous ethanol by ultrasonication, add it to the melting device, melt it under an argon atmosphere and a pressure of -0.08 MPa to 0.03 MPa, and obtain the alloy ingot after cooling. S2: Using a single-roller melt quenching system, the alloy ingot in S1 is melted to form a molten alloy liquid, which is then sprayed onto a rotating copper wheel at a speed of 42 m / s to solidify and form Fe-Nb-BY amorphous alloy strip.

[0011] Thirdly, the present invention provides the application of the above-mentioned Fe-Nb-BY amorphous alloy in soft magnetic materials.

[0012] Compared with the prior art, the present invention has the following beneficial effects: This invention reduces the Nb content to 0.3%, significantly lowering production costs while maintaining the amorphous structure. By completely replacing the basic system with Y, the loss of ferromagnetic elements can be minimized, resulting in excellent soft magnetic properties.

[0013] Y not only acts as a strong oxyphile element to purify melts and refine microstructures, but also, due to its larger atomic radius and negative enthalpy of mixing, it can further enhance the "disorder" of the melt and the diversity of short-range ordered structures, thereby improving glass-forming ability and potentially optimizing the magnetic anisotropy of materials through electronic interactions.

[0014] Y and B have a strong negative mixing enthalpy (BY: -50 kJ / mol), which can form metastable short-range clusters, hindering atomic diffusion and suppressing the nucleation of crystalline phases, thereby reducing the difficulty of continuous strip forming. At the same time, Y can effectively improve the impurity tolerance of amorphous alloys, reduce the difficulty of magnetic domain wall movement, weaken the strong ferromagnetic exchange interaction between Fe atoms, and increase the width of magnetic domain walls. This allows amorphous alloys to maintain high forming ability while also possessing low coercivity (≤27 A / m) and high saturation magnetization (≥1.43 T).

[0015] The critical cooling rate of the Fe-Nb-BY amorphous alloy in this application is 1.2 × 10⁻⁶. 6 ~1.5×10 6 K / s, while the critical cooling rate of the traditional Fe-Nb-B ternary amorphous alloy (without Y addition) is 3.5 × 10 K / s. 6 ~4.0×10 6 K / s, the critical cooling rate of the alloy in this application is reduced by about 60%, indicating a significant improvement in glass-forming ability. The lower cooling rate means that it is easier to prepare large-size, thick-gauge amorphous ribbons, reducing the process difficulty of industrial continuous forming. Attached Figure Description

[0016] Figure 1 The images show the XRD patterns of the Fe-Nb-BY amorphous alloy strips from Examples 1 and 2. Figure 2The images show the XRD patterns of the Fe-Nb-BY amorphous alloy strips from Comparative Examples 1 to 3. Figure 3 XRD curve images of Fe-Nb-B-Er amorphous alloy strips in Comparative Examples 4 to 5; Figure 4 The saturation magnetization curves of the Fe-Nb-BY soft magnetic alloy strips in Examples 1 to 2 and Comparative Examples 1 to 3 of this application are shown. Figure 5 The saturation magnetization curves are for the Fe-Nb-B-Er soft magnetic alloy strips in Comparative Examples 4 to 5 of this application. Detailed Implementation

[0017] To better illustrate the purpose, technical solution, and advantages of this application, the following detailed description, in conjunction with specific embodiments, aims to explain the content of this application in detail, rather than to limit it. All other embodiments obtained by those skilled in the art without inventive effort are within the protection scope of this application.

[0018] The first aspect of this application provides a Fe-Nb-BY amorphous alloy having the following atomic percentage expression: (Fe 85 Nb 0.3 B 14.7 ) 100-x Y x , where 0.2≤x≤0.3.

[0019] The Fe-Nb-BY amorphous alloy of this application combines the Fe-B-Nb ternary system with trace rare earth element Y. By increasing the Fe content and decreasing the Nb content in the Fe-B-Nb ternary system, the ternary system and trace rare earth element work synergistically. This not only effectively improves the impurity tolerance of the amorphous alloy and promotes the enhancement of amorphous formation capability, but also reduces the difficulty of magnetic domain wall movement under magnetic field. Furthermore, it weakens the strong ferromagnetic exchange interaction between Fe atoms and increases the width of magnetic domain walls. As a result, the amorphous alloy maintains high formation capability while also possessing low coercivity and high saturation magnetic strength.

[0020] In some embodiments of this application, the atomic percentage of the Fe-Nb-BY amorphous alloy is expressed as (Fe 85 Nb 0.3 B 14.7 ) 99.8 Y 0.2 .

[0021] In some embodiments of this application, the atomic percentage of the Fe-Nb-BY amorphous alloy is expressed as (Fe 85 Nb 0.3 B 14.7 ) 99.7 Y 0.3 .

[0022] In some embodiments of this application, the X-ray diffraction pattern of the Fe-Nb-BY amorphous alloy contains diffraction peaks in the range of 2θ from 32.5° to 55°, and the half-width at half-maximum (FWHM) of the diffraction peaks is from 0.35 to 0.51.

[0023] In some embodiments of this application, the Fe-Nb-BY amorphous alloy strip has a width of 1~2mm and a thickness of 20~25μm and is a completely amorphous structure.

[0024] The second aspect of this application provides a method for preparing Fe-Nb-BY amorphous alloy, comprising the following steps: Step 1: Prepare raw materials High-purity iron, pure niobium, pure boron, and pure yttrium are placed into a water-cooled copper crucible in the smelting furnace according to the designed composition ratio. During the placement process, boron, which has a higher melting point, is first placed at the bottom of the crucible, followed by the other raw materials in sequence. Finally, iron particles are placed on the top layer to prevent the raw materials from splashing during the smelting process.

[0025] Step 2: Vacuuming Close the furnace door of the electric arc melting furnace. First, use a mechanical pump to pre-evacuate the furnace cavity, and then perform three gas purgings with high-purity argon. When the vacuum level drops below 10 Pa, turn on the molecular pump to finely evacuate to 3.5 × 10 Pa. -3 The pressure is below 0.05 MPa, then the molecular pump is turned off, and high-purity argon gas at a pressure of 0.05 MPa is introduced as a protective atmosphere.

[0026] Step 3: Melting alloy ingots During smelting, first bring the tungsten electrode of the electric arc furnace close to the surface of the raw material, about 5 mm away, turn on the current switch, press the arc ignition button, and after successful arc ignition, slowly increase the current to about 400A. In order to make the alloy raw material melt evenly, turn on the magnetic stirring switch. After the alloy melt is fully stirred evenly, turn off the magnetic stirring and the current. After the melt cools down, flip it over and repeat the smelting process four times to ensure uniformity.

[0027] Step 4: Preparation of amorphous ribbon The alloy ingot obtained in step three is ground with a grinding wheel to remove the surface oxide layer, and then the alloy ingot is crushed. The dust and oil stains on the surface of the crushed alloy are cleaned with alcohol, and the cleaned alloy fragments are placed in a quartz tube; Place the quartz tube into the heating coil of the spinning machine, close the furnace door, perform three gas purgings with high-purity argon, evacuate to below 10 Pa using a mechanical pump, then turn on the molecular pump and evacuate to 3.5 × 10 Pa. -3 Pa, then high-purity argon gas is introduced as a protective atmosphere, and the pressure difference is adjusted to 0.15 MPa. The alloy is heated to a molten state and quickly sprayed onto a copper rod rotating at 42 m / s. The high thermal conductivity of copper is used to cool the molten metal at a rate greater than the critical cooling rate to form an amorphous ribbon.

[0028] A third aspect of this application provides an application of Fe-Nb-BY amorphous alloy in soft magnetic materials.

[0029] The present invention will be described in detail below with reference to the embodiments, but the implementation of the present invention is not limited thereto.

[0030] Example 1 This embodiment describes a Fe-Nb-BY ribbon amorphous alloy, with the atomic percentage expression being (Fe 85 Nb 0.3 B 14.7 ) 99.8 Y 0.2 The strip has a thickness of 25μm and a width of 1.5mm.

[0031] Its preparation method includes the following steps: (1) Ingredients: Fe, B, Nb and Y elements with a purity of ≥99.9% are used as raw materials and weighed according to atomic percentage converted to mass percentage.

[0032] (2) Smelting: Place the raw materials in a water-cooled copper crucible in the order of high-melting-point metals at the bottom and low-melting-point metals at the top. Evacuate to a vacuum of 3.5 × 10⁻⁶. -3 Pa, then high-purity argon gas with a purity of 99.99 wt% is introduced as a protective gas until the pressure inside the furnace reaches -0.08 MPa and the gas introduction is stopped. After all the raw materials have melted to form an alloy ingot, it is allowed to cool naturally and then turned over. It is then melted again and the magnetic stirring is turned on. The melting current is increased to 450 A, and the melting is repeated 4 times to obtain the alloy ingot.

[0033] (3) Single-roll quenching: After crushing and cleaning the ingot, place it into a quartz tube and then into the heating coil of the belt spinning machine. Evacuate to 3.5 × 10⁻⁶ mm. -3 Pa, filled with argon gas, the pressure difference between the gas storage tank and the vacuum chamber of the ribbon spinning equipment is adjusted to 0.15 MPa, heated to complete melting and then vertically sprayed onto a copper roller rotating at 42 m / s to obtain amorphous ribbon.

[0034] Example 2 This embodiment presents a Fe-Nb-BY ribbon amorphous alloy, the preparation method of which is basically the same as that in Example 1, the only difference being that the alloy composition is (Fe 85 Nb 0.3 B 14.7 ) 99.7 Y 0.3 The strip has a thickness of 23μm and a width of 1.5mm.

[0035] Comparative Example 1 The difference between this comparative example and Example 1 is that its alloy composition is (Fe 85 Nb 0.3 B 14.7 ) 99.9 Y 0.1 .

[0036] Comparative Example 2 The difference between this comparative example and Example 1 is that its alloy composition is (Fe 85 Nb 0.3 B 14.7 ) 99.6 Y 0.4 .

[0037] Comparative Example 3 The difference between this comparative example and Example 1 is that its alloy composition is (Fe 85 Nb 0.3 B 14.7 ) 99.5 Y 0.5 .

[0038] Comparative Example 4 The difference between this comparative example and Example 1 is that Er is used instead of Y, and its alloy composition is (Fe 85 Nb 0.3 B 14.7 ) 99.8 Er 0.2 .

[0039] Comparative Example 5 The difference between this comparative example and Example 2 is that Er is used instead of Y, and its alloy composition is (Fe 85 Nb 0.3 B 14.7 ) 99.7 Er 0.3 .

[0040] Comparative Example 6 The difference between this comparative example and Example 2 is that the amount of Y added is 0, and its alloy composition is (Fe 85 Nb 0.3 B 14.7 ).

[0041] Performance testing: 1) XRD test The Fe-Nb-BY amorphous alloy strips from Examples 1 and 2 were subjected to XRD tests, and the test results are as follows: Figure 1 As shown.

[0042] according to Figure 1 It can be seen that (Fe) 85 Nb 0.3 B 14.7 ) 100-x Y x When x=0.2 and 0.3, the diffraction peaks in the XRD patterns of the amorphous alloys all show obvious "bun-like" shapes, indicating that they have good amorphous forming ability.

[0043] XRD tests were performed on the Fe-Nb-BY and Fe-Nb-B-Er alloy strips from Comparative Examples 1 to 5. The test results are as follows: Figure 2 and Figure 3 As shown.

[0044] according to Figure 2 It can be seen that (Fe) 85 Nb 0.3 B 14.7 ) 100-x Y x When x = 0.1, 0.4, and 0.5, the strip exhibits obvious crystallization peaks. This phase structure transformation indicates that excessive addition of Y leads to the precipitation of α-Fe and Fe2B phases during rapid quenching, significantly reducing the alloy's amorphous formation capability. Too much or too little Y content is actually detrimental to improving its amorphous formation capability.

[0045] according to Figure 3 It can be observed that when (Fe) 85 Nb 0.3 B 14.7 ) 100-x Er x When x=0.2 and 0.3, the diffraction peaks in the XRD patterns of the corresponding Fe-Nb-B-Er amorphous alloys all show obvious "bun-shaped" appearance, indicating that they have good amorphous forming ability.

[0046] The critical cooling rate of the Fe-Nb-BY amorphous alloy in this application is 1.2 × 10⁻⁶. 6 ~1.5×10 6 K / s, while the critical cooling rate of the traditional Fe-Nb-B ternary amorphous alloy (without Y addition) is 3.5 × 10 K / s. 6 ~4.0×10 6K / s, the critical cooling rate of the alloy in this application is reduced by about 60%, indicating a significant improvement in glass-forming ability. The lower cooling rate means that it is easier to prepare large-size, thick-gauge amorphous ribbons, reducing the process difficulty of industrial continuous forming.

[0047] 2) Coercivity and saturation magnetization test The coercivity and saturation magnetization of the Fe-Nb-BY amorphous alloy strips in Examples 1 and 2, and Comparative Examples 1 to 6, were tested using a vibrating sample magnetometer (VSM). The vibration of the sample in the coil induces an alternating signal in the detection coil. This alternating voltage is proportional to the magnetic moment of the sample. The coercivity and saturation magnetization were calculated from the hysteresis loop measured by the VSM. The results are shown in Table 1. Figure 3 and Figure 4 As shown.

[0048] Table 1

[0049] According to the data in Table 1, the coercivity of the Fe-Nb-BY amorphous alloys in Examples 1 and 2 is 26.95 A / m and 26.24 A / m, respectively, and the saturation magnetization is 1.45 T and 1.43 T, respectively. This indicates that the Fe-Nb-BY amorphous alloy of this application has low coercivity while maintaining high saturation magnetization. According to Comparative Examples 4 and 5, it can also be found that although the addition of Er element improves the amorphous forming ability of the alloy strip, its saturation magnetization and coercivity have deteriorated to varying degrees.

[0050] The annealing window Δ in Embodiment 1 of this application T x =86K, compared to traditional Fe-Nb-B ternary amorphous alloys (Comparative Example 6, Δ T x =52K) increased by 65%, Δ in Example 2 T x =74K, a 42% improvement over existing technologies; compared to alloys with Er added to the same system (Comparative Examples 4 and 5, Δ T x =60~65K) also improved by 15%~43%. The wider annealing window means that the soft magnetic properties can be further optimized through the annealing process over a wider temperature range, and the temperature range for high-temperature service is wider, improving the reliability of engineering applications.

[0051] Comparing Examples 1 and 2 with Comparative Examples 4 to 6, it can be found that element Y is superior to element Er in improving amorphous forming ability, saturation magnetization, and coercivity. The atomic radius of element Y (1.82 Å) is slightly larger than that of element Er (1.75 Å), which makes element Y improve the atomic disorder of the ribbon more significantly than element Er. This, in turn, has a more significant effect on the strong ferromagnetic exchange interaction between Fe atoms, thus improving the amorphous ribbon forming ability while maintaining high saturation magnetization and low coercivity.

[0052] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application and are not intended to limit the scope of protection of this application. Although this application has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of this application without departing from the substance and scope of the technical solutions of this application.

Claims

1. A Fe-Nb-BY amorphous alloy, characterized in that, The expression has the following atomic percentage: (Fe 85 Nb 0.3 B 14.7 ) 100-x Y x Where 0.2≤x≤0.3; The saturation magnetization Ms ≥ 1.43T and the coercivity Hc ≤ 27 A / m of the amorphous alloy.

2. The Fe-Nb-BY amorphous alloy according to claim 1, characterized in that, The atomic percentage expression for the Fe-Nb-BY amorphous alloy is (Fe 85 Nb 0.3 B 14.7 ) 99.8 Y 0.2 .

3. The Fe-Nb-BY amorphous alloy according to claim 1, characterized in that, The atomic percentage expression for the Fe-Nb-BY amorphous alloy is (Fe 85 Nb 0.3 B 14.7 ) 99.7 Y 0.3 .

4. The Fe-Nb-BY amorphous alloy according to any one of claims 1 to 3, characterized in that, The X-ray diffraction pattern of the Fe-Nb-BY amorphous alloy shows diffraction peaks in the range of 2θ from 32.5° to 55°, with a half-width of 0.35 to 0.51 and no obvious crystallization peaks.

5. The Fe-Nb-BY amorphous alloy according to any one of claims 1 to 3, characterized in that, The amorphous ribbon has a width of 1-2 mm and a thickness of 20-25 μm and is a completely amorphous structure.

6. A method for preparing the Fe-Nb-BY amorphous alloy according to any one of claims 1 to 3, characterized in that, Includes the following steps: S1: Weigh the elemental metals according to the atomic percentage of the Fe-Nb-BY amorphous alloy, add them to the melting device, melt them in an argon atmosphere, and obtain the alloy ingot after cooling. S2: The alloy ingot in S1 is melted into a molten alloy liquid using a single-roll melt quenching system. The molten alloy liquid is then sprayed onto a rotating casting wheel to solidify and form Fe-Nb-BY amorphous alloy strip.

7. The preparation method according to claim 6, characterized in that, The purity of the metallic element in S1 is all above 99.9%, and it is subjected to ultrasonic cleaning with petroleum ether and ultrasonic cleaning with anhydrous ethanol in sequence before being added to the smelting device.

8. The preparation method according to claim 6, characterized in that, The smelting pressure described in S1 is -0.08MPa to 0.03MPa; the rotational speed of the casting wheel described in S2 is 42m / s.

9. The application of the Fe-Nb-BY amorphous alloy according to any one of claims 1 to 3 in soft magnetic materials.

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