Near-zero magnetostrictive iron-cobalt-based magnetically soft alloy and preparation method thereof

Abstract

The invention relates to an iron-cobalt-based magnetically soft alloy, in particular to a near-zero magnetostrictive iron-cobalt-based magnetically soft alloy and a preparation method thereof. The alloy comprises the following chemical components in percentage by mole: 2% of V or Ni or Si, 19%-26% of Fe and the balance of Co. The preparation method comprises the following steps: S1, preparing furnace charge; s2, heating and smelting to obtain molten steel conforming to chemical components; s3, cooling to obtain an alloy ingot; s4, the alloy ingot is subjected to solid solution for 1-6 h at the temperature of 1100-1200 DEG C; s5, annealing; and S6, segmented cooling is conducted, and the near-zero magnetostrictive iron-cobalt-based magnetically soft alloy is obtained. The transition element vanadium or nickel or silicon is doped in the cobalt-rich iron-cobalt alloy, so that a crystal structure composed of iron atoms and cobalt atoms in the iron-cobalt alloy is converted into a face-centered cube from a body-centered cube; meanwhile, vanadium or nickel or silicon can influence the movement of a magnetic domain in the iron-cobalt alloy, so that the magnetomechanical behavior of the iron-cobalt alloy is improved, and near-zero magnetostriction is realized.

Description

Technical Field

[0001] The invention relates to an iron-cobalt-based soft magnetic alloy, in particular to a near-zero magnetostriction iron-cobalt-based soft magnetic alloy and a preparation method thereof. Background Art

[0002] Soft magnetic materials play a vital role in various industrial and technological applications, where optimizing magnetic properties is crucial. Co-rich iron-cobalt alloys have attracted much attention due to their outstanding magnetic properties, especially high magnetocrystalline anisotropy, high saturation magnetization, and excellent magnetostrictive behavior.

[0003] However, with the continuous development of high-performance electronics, power generation, and energy conversion systems, the performance requirements for magnetic materials are also increasing. To meet these growing demands, the magnetic properties of iron-cobalt alloys need to be further improved and enhanced. Existing research has shown that the addition of vanadium to iron-cobalt alloys has the potential to increase their saturation magnetization, thereby further improving their magnetic properties. This improved magnetic performance is extremely important in applications such as high-density magnetic storage media, sensors, and high-efficiency electric motors.

[0004] When designing soft magnetic alloys, the addition of different elements can have varying effects on the alloy's mechanical and magnetic properties. Iron-cobalt-vanadium alloys, due to their excellent mechanical and magnetic properties, are widely used in applications such as motor rotors. However, their high magnetostriction coefficient can lead to cracking and damage during use. Summary of the Invention

[0005] The purpose of the present invention is to solve the technical problem that the existing soft magnetic alloy has a high magnetostriction coefficient, which easily leads to cracking and damage of parts during use, and to provide a near-zero magnetostriction iron-cobalt based soft magnetic alloy and a preparation method thereof.

[0006] To solve the above technical problems, the present invention provides the following technical solutions:

[0007] The invention discloses a near-zero magnetostriction iron-cobalt-based soft magnetic alloy, whose chemical composition comprises, in molar percentage, 2% of V or Ni or Si, 19%-26% of Fe, and the balance of Co.

[0008] Furthermore, in terms of molar percentage, the chemical composition includes: 72.52% Co, 25.48% Fe, and 2% V or Ni or Si.

[0009] Furthermore, in terms of molar percentage, the chemical composition includes: 76.44% Co, 21.56% Fe, and 2% V or Ni or Si.

[0010] Furthermore, its chemical composition includes, in mole percentage, 78.4% Co, 19.6% Fe, and 2% V or Ni or Si.

[0011] A method for preparing a near-zero magnetostrictive iron-cobalt-based soft magnetic alloy comprises the following steps:

[0012] S1, prepare the charge;

[0013] S2. Place the charge into the crucible of an electric arc furnace, and raise the furnace temperature to 1100-1250°C at a heating rate of 3-6°C / min under an argon protective atmosphere;

[0014] Heat and melt the charge for 1-3 hours to obtain molten steel with the chemical composition;

[0015] S3, cooling the molten steel to obtain an alloy ingot;

[0016] S4, solutionizing the alloy ingot at 1100-1200°C for 1-6 hours;

[0017] S5. The alloy ingot after the solid solution is vacuum sealed in a quartz tube, and argon gas is injected to make the vacuum degree in the quartz tube -0.1 MPa; annealing is performed at 970-1000° C. for 1-6 hours;

[0018] S6. After annealing is completed, the alloy ingot is cooled to 300°C at a cooling rate of 3-6°C / min, and then furnace-cooled to room temperature. After cooling, a near-zero magnetostrictive iron-cobalt-based soft magnetic alloy is obtained.

[0019] Furthermore, in step S1, the charge includes an iron-cobalt alloy, and metal vanadium or metal nickel or single crystal silicon.

[0020] Furthermore, step S2 may also be:

[0021] Place the charge into the crucible of the electric arc furnace and raise the furnace temperature to 1100-1250°C at a heating rate of 3-6°C / min under argon protective atmosphere;

[0022] The charge is repeatedly smelted more than four times, with a single smelting time of 2 hours; after the smelting is completed, molten steel with the chemical composition is obtained.

[0023] Furthermore, in the step S5, gas washing is further performed before the argon gas is injected:

[0024] The gas washing method is: injecting argon into the quartz tube, filling the quartz tube with argon, and then extracting the argon, repeating this process three times to complete the gas washing.

[0025] Compared with the prior art, the present invention has the following beneficial effects:

[0026] 1. The present invention provides a near-zero magnetostrictive iron-cobalt-based soft magnetic alloy and a preparation method thereof. Vanadium, nickel, or silicon is doped into the iron-cobalt alloy as a transition element, so that the crystal structure composed of iron atoms and cobalt atoms is transformed from body-centered cubic to face-centered cubic. At the same time, the transition elements vanadium, nickel, or silicon affect the movement of magnetic domains within the iron-cobalt alloy, thereby improving the magnetomechanical behavior of the iron-cobalt alloy and achieving near-zero magnetostriction.

[0027] 2. The near-zero magnetostrictive iron-cobalt-based soft magnetic alloy and its preparation method provided by the present invention, V and Ni as representatives of transition metal elements, and Si as a representative of transition non-metallic elements, have the potential to change the magnetic behavior of the iron-cobalt alloy at the atomic level; vanadium and nickel can refine the grains of the iron-cobalt alloy, helping to enhance the directionality of the magnetization intensity, thereby producing stronger magnetic properties; silicon is a non-metallic element, and a suitable proportion in the iron-cobalt alloy will promote the amorphous behavior of the iron-cobalt alloy.

[0028] 3. The near-zero magnetostriction iron-cobalt-based soft magnetic alloy and its preparation method provided by the present invention optimize the magnetic properties of the Co-rich iron-cobalt alloy by controlling doping, and improve the saturation magnetization intensity, magnetocrystalline anisotropy and overall performance; its low magnetostriction coefficient is beneficial to the service characteristics when used in motor rotors; at the same time, compared with the existing technology, the present invention has better soft magnetic properties and a lower magnetostriction coefficient, which improves the alloy's broad application prospects in related fields such as electricity and electronics. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 The temperature-time curve of the preparation method according to the embodiment of the present invention;

[0030] Figure 2 X-ray diffraction patterns of Examples 1 to 3 of the present invention doped with 2% vanadium and the comparative example not doped with 2% vanadium;

[0031] Figure 3 hysteresis loops and magnetic property variation diagrams of Examples 1 to 3 of the present invention doped with 2% vanadium;

[0032] Figure 4 The magnetostrictive behavior diagram and corresponding diffraction pattern of Example 2 of the present invention doped with 2% vanadium;

[0033] Figure 5 These are the high-resolution topography and electron diffraction patterns corresponding to Example 2 of the present invention. DETAILED DESCRIPTION

[0034] The following will clearly and completely describe the technical solutions of the present invention in conjunction with the accompanying drawings. Obviously, the embodiments described are only some of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts shall fall within the scope of protection of the present invention.

[0035] The invention discloses a near-zero magnetostriction iron-cobalt-based soft magnetic alloy, whose chemical composition comprises, in molar percentage, 2% of V or Ni or Si, 19%-26% of Fe, and the balance of Co.

[0036] like Figure 1 As shown, a method for preparing a near-zero magnetostrictive iron-cobalt based soft magnetic alloy comprises the following steps:

[0037] S1, prepare the charge;

[0038] The charge includes an iron-cobalt alloy, and metallic vanadium or metallic nickel or single crystal silicon;

[0039] S2. Place the charge into the crucible of an electric arc furnace, and raise the furnace temperature to 1100-1250°C at a heating rate of 3-6°C / min under an argon protective atmosphere;

[0040] The charge is heated and smelted for 1-3 hours to obtain molten steel meeting the above chemical composition;

[0041] S3, cooling the molten steel to obtain an alloy ingot;

[0042] S4, solutionizing the alloy ingot at 1100-1200°C for 1-6 hours;

[0043] S5. After the solid solution treatment, the alloy ingot is vacuum sealed in a quartz tube, argon gas is injected into the quartz tube until the argon gas fills the quartz tube, and then the argon gas is extracted. This is repeated three times to complete the gas washing.

[0044] After the purge is completed, argon is injected into the quartz tube to make the vacuum degree inside the quartz tube -0.1MPa; annealing is performed at 970-1000°C for 1-6 hours;

[0045] S6. After annealing is completed, the alloy ingot is cooled to 300°C at a cooling rate of 3-6°C / min, and then furnace-cooled to room temperature. After cooling, a near-zero magnetostrictive iron-cobalt-based soft magnetic alloy is obtained.

[0046] Specific examples are given below.

[0047] Example 1

[0048] 1) Prepare a furnace charge; the charge includes an iron-cobalt alloy, and metallic vanadium or metallic nickel or single crystal silicon; the charge includes 0.176 g of metallic vanadium and 9.824 g of an iron-cobalt alloy, wherein Fe:Co in the iron-cobalt alloy is 26:74.

[0049] 2) placing the charge into a crucible of an electric arc furnace, raising the furnace temperature to 1209° C. at a heating rate of 5° C. / min under an argon protective atmosphere; heating and melting the charge for 2 h to obtain molten steel;

[0050] 3) cooling the molten steel to obtain an alloy ingot;

[0051] 4) Solutionizing the alloy ingot at 1100°C for 6 hours;

[0052] 5) The alloy ingot after solid solution is vacuum sealed in a quartz tube, and argon is injected into the quartz tube until the argon fills the quartz tube, and then the argon is extracted. Repeat this process three times to complete the gas washing.

[0053] After the purge is completed, argon is injected into the quartz tube to make the vacuum degree inside the quartz tube -0.1MPa; annealing is performed at 970-1000°C for 1-6 hours;

[0054] 6) After annealing, the alloy ingot is cooled to 300°C at a cooling rate of 5°C / min, and then furnace cooled to room temperature. After cooling, a near-zero magnetostrictive iron-cobalt-based soft magnetic alloy is obtained;

[0055] The chemical composition of the near-zero magnetostrictive iron-cobalt-based soft magnetic alloy prepared in Example 1 was measured by a spectrometer. In terms of molar percentage, the chemical composition of the near-zero magnetostrictive iron-cobalt-based soft magnetic alloy prepared in Example 1 included: 72.52% Co, 25.48% Fe, and 2% V.

[0056] Example 2

[0057] The difference between Example 2 and Example 1 is that the charge includes 0.175 g of metallic vanadium and 9.825 g of iron-cobalt alloy, wherein the ratio of Fe to Co in the iron-cobalt alloy is 22:78.

[0058] The chemical composition of the near-zero magnetostrictive iron-cobalt-based soft magnetic alloy prepared in Example 2 includes, in mole percentage, 76.44% Co, 21.56% Fe, and 2% V.

[0059] Example 3

[0060] The difference between Example 3 and Example 1 is that the charge includes 0.175 g of metallic vanadium and 9.825 g of iron-cobalt alloy, wherein the ratio of Fe to Co in the iron-cobalt alloy is 20:80.

[0061] The chemical composition of the near-zero magnetostrictive iron-cobalt-based soft magnetic alloy prepared in Example 3 includes, in mole percentage, 78.4% Co, 19.6% Fe, and 2% V.

[0062] Table 1: Comparative table of chemical compositions of the iron-cobalt based soft magnetic alloys prepared in Examples 1 to 3 and the iron-cobalt alloys not doped with metallic vanadium

[0063]

[0064] The iron-cobalt-based soft magnetic alloys obtained in Examples 1 to 3 and the iron-cobalt alloys of the comparative example were subjected to XRD analysis to obtain X-ray diffraction patterns of different vanadium-doped iron-cobalt alloys and the iron-cobalt alloys not doped with vanadium. Figure 2 .

[0065] XRD analysis was performed on the iron-cobalt based soft magnetic alloys obtained in Examples 1 to 3 to obtain the hysteresis loops and magnetic property change diagrams of different iron-cobalt alloys doped with vanadium, as shown in FIG. Figure 3 .

[0066] Since the crystal structure of iron-cobalt alloy is closely related to the composition ratio, a single body-centered cubic structure can be obtained at an equal atomic ratio; body-centered cubic structure and face-centered cubic structure can coexist in Co-rich areas; its magnetic properties first increase and then decrease with the increase of Co content in the ratio, and the best saturation magnetization capacity is obtained at an iron-cobalt atomic ratio of 1:4, and a near-zero magnetostriction coefficient is obtained due to its special coexisting crystal structure.

[0067] The iron-cobalt-based soft magnetic alloy prepared in Example 2 was selected for magnetostriction coefficient testing to obtain the magnetostriction behavior diagram and corresponding diffraction pattern of the iron-cobalt-based soft magnetic alloy in Example 2; specifically, Figure 4 .

[0068] The high-resolution morphology and electron diffraction pattern of the iron-cobalt based soft magnetic alloy prepared in Example 2 were analyzed by XRD; Figure 5 .

[0069] The iron-cobalt-based soft magnetic alloy prepared in Example 2 has a saturation magnetization of 199.4 emu / g and a magnetostriction coefficient of approximately 20 ppm, demonstrating comparable service characteristics to the low-magnetostrictive Invar alloy. XRD analysis revealed body-centered cubic and face-centered cubic peaks of similar intensity across the entire spectrum, which were verified using transient electromagnetic TEM (TEM).

[0070] In other embodiments of the present invention, the difference from the embodiment is that step S2 may also be:

[0071] The charge was placed in a crucible of an electric arc furnace and the furnace temperature was raised to 1209°C at a heating rate of 5°C / min under an argon protective atmosphere;

[0072] The charge is repeatedly smelted for more than four times, with a single smelting time of 2 hours;

[0073] After smelting is completed, molten steel with the correct chemical composition is obtained.

[0074] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or substitutions within the technical scope disclosed in the present invention shall be covered by the scope of protection of the present invention. Therefore, the scope of protection of the present invention shall be subject to the scope of protection of the claims.

Claims

1. A near-zero magnetostrictive iron-cobalt based soft magnetic alloy, characterized in that: Measured in mole percentage, its chemical composition includes: 2% of V or Ni or Si, 19%-26% of Fe, and the balance of Co.

2. The near-zero magnetostrictive iron-cobalt-based soft magnetic alloy according to claim 1, characterized in that: In terms of molar percentage, its chemical composition includes: 72.52% Co, 25.48% Fe, and 2% V or Ni or Si.

3. The near-zero magnetostrictive iron-cobalt-based soft magnetic alloy according to claim 1, characterized in that: In terms of molar percentage, its chemical composition includes: 76.44% Co, 21.56% Fe, and 2% V or Ni or Si.

4. The near-zero magnetostrictive iron-cobalt-based soft magnetic alloy according to claim 1, characterized in that: In terms of molar percentage, its chemical composition includes: 78.4% Co, 19.6% Fe, and 2% V or Ni or Si.

5. A method for preparing a near-zero magnetostrictive iron-cobalt based soft magnetic alloy, characterized in that: The steps include: S1, prepare the charge; S2. Place the charge into the crucible of an electric arc furnace, and raise the furnace temperature to 1100-1250°C at a heating rate of 3-6°C / min under an argon protective atmosphere; Heat and melt the charge for 1-3 hours to obtain molten steel with the chemical composition; S3, cooling the molten steel to obtain an alloy ingot; S4, solutionizing the alloy ingot at 1100-1200°C for 1-6 hours; S5. The alloy ingot after the solid solution is vacuum sealed in a quartz tube, and argon gas is injected to make the vacuum degree in the quartz tube -0.1 MPa; annealing is performed at 970-1000° C. for 1-6 hours; S6. After annealing is completed, the alloy ingot is cooled to 300°C at a cooling rate of 3-6°C / min, and then furnace-cooled to room temperature. After cooling, a near-zero magnetostrictive iron-cobalt-based soft magnetic alloy is obtained.

6. The method for preparing the near-zero magnetostrictive iron-cobalt based soft magnetic alloy according to claim 5, characterized in that: In step S1 , the furnace charge includes an iron-cobalt alloy, and metal vanadium or metal nickel or single crystal silicon.

7. The method for preparing the near-zero magnetostrictive iron-cobalt based soft magnetic alloy according to claim 5, characterized in that: Step S2 may also be: Place the charge into the crucible of the electric arc furnace and raise the furnace temperature to 1100-1250°C at a heating rate of 3-6°C / min under argon protective atmosphere; The charge is repeatedly smelted more than four times, with a single smelting time of 2 hours; after the smelting is completed, molten steel with the chemical composition is obtained.

8. The method for preparing the near-zero magnetostrictive iron-cobalt based soft magnetic alloy according to claim 5, characterized in that: In the step S5, the step further includes washing before injecting argon gas: The gas washing method is: injecting argon into the quartz tube, filling the quartz tube with argon, and then extracting the argon, repeating this process three times to complete the gas washing.

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