A high entropy alloy soft magnetic material for aerospace field and preparation method thereof

Abstract

The invention discloses a high entropy alloy soft magnetic material for aerospace and a preparation method thereof, and relates to the field of soft magnetic materials for aerospace. The high entropy alloy soft magnetic material for aerospace includes the following raw materials in atomic percentage: 10-50% iron, 10-50% cobalt, 5-20% nickel, 1-10% copper, 2-20% aluminum and 2-20% molybdenum. The present invention also provides a preparation method of the high entropy alloy soft magnetic material for aerospace. The saturation magnetization of the high entropy alloy soft magnetic material for aerospace obtained by the method provided by the present invention reaches 169.86emu / g, the coercive force is 27Oe, the compressive yield strength is 952.23MPa, and the plastic strain exceeds 100%, which effectively solves the problems of poor plasticity, low saturation magnetization and high coercive force of the existing high entropy alloy soft magnetic material.

Description

Technical Field

[0001] The present invention relates to the field of soft magnetic materials for aerospace use, and in particular to a high entropy alloy soft magnetic material for aerospace use and a preparation method thereof. Background Art

[0002] Soft magnetic materials are magnetic materials with low coercivity and high magnetic permeability. They are easy to magnetize and demagnetize. Their main functions are magnetic conductivity, conversion and transmission of electromagnetic energy. They are widely used in various electric energy conversion equipment. Such as new energy vehicles, electronics industry, aerospace and other industries. High-temperature soft magnetic materials are key materials for the development of aviation, aerospace and advanced weapon systems. They are widely used to make important components such as engine rotors and magnetic shafts. The operating temperature is 400-800℃. Therefore, soft magnetic materials used in this field need to have both excellent soft magnetic properties and high-temperature mechanical properties. However, among traditional soft magnetic materials, although silicon steel sheets have very high saturation magnetization, they are relatively brittle. The saturation magnetization of Permalloy and ferrite soft magnetic materials is low, which is not conducive to the miniaturization of products. Amorphous alloys have high saturation magnetization and low coercivity, but they are relatively brittle and have poor high temperature resistance.

[0003] The design of multiple main elements in high entropy alloys improves the mechanical properties of the alloys and also improves their thermal stability. High entropy is beneficial to the stability of the alloy structure and can avoid the pinning of magnetic domain walls caused by phase boundaries, thereby obtaining a smaller coercive force. In addition, the severe lattice distortion in high entropy alloys increases the resistance to electron movement, resulting in an increase in resistivity, which in turn enables it to obtain low eddy current losses. Therefore, high entropy alloys are expected to become a new generation of soft magnetic materials with excellent soft magnetic properties and mechanical properties.

[0004] However, in high-entropy alloy soft magnetic materials, due to the multi-principal component design, the relative content of magnetic elements such as iron and cobalt will inevitably decrease, which will lead to a decrease in the saturation magnetization of the alloy. The coercive force of high-entropy alloy soft magnetic materials is generally large. In addition, the plasticity of high-entropy alloy soft magnetic materials is generally poor, which is not conducive to the reprocessing of materials. Summary of the invention

[0005] In view of the above-mentioned deficiencies in the prior art, the present invention provides a high-entropy alloy soft magnetic material for the aerospace field and a preparation method thereof. The high-entropy alloy soft magnetic material for the aerospace field has the characteristics of high plasticity, high saturation magnetization intensity and low coercivity, meets the requirements of new soft magnetic materials for mechanical properties, thermal stability and soft magnetic properties, and effectively solves the problems of poor plasticity, low saturation magnetization intensity and high coercivity of existing high-entropy alloy soft magnetic materials.

[0006] To achieve the above-mentioned purpose, the technical solution adopted by the present invention to solve its technical problem is: to provide a high entropy alloy soft magnetic material for the aerospace field, which is composed of the following atomic percentage raw materials: 40.83% iron, 40.81% cobalt, 10.20% nickel, 2.04% copper, 3.06% aluminum and 3.06% molybdenum.

[0007] Furthermore, the above-mentioned iron, cobalt, nickel, copper, aluminum and molybdenum are single metal blocks with a purity of 99.99%.

[0008] Furthermore, the preparation method of the high entropy alloy soft magnetic material used in the aerospace field specifically comprises the following steps:

[0009] S1, take a copper block and a molybdenum block, introduce a protective gas under a vacuum state, and smelt them to obtain a copper-molybdenum alloy ingot;

[0010] S2, taking an iron block, a cobalt block, a nickel block and an aluminum block, introducing a protective gas under a vacuum state, and smelting to obtain an iron-cobalt-nickel-aluminum alloy ingot;

[0011] S3. The copper-molybdenum alloy ingot obtained in step S1 and the iron-cobalt-nickel-aluminum alloy ingot obtained in step S2 are smelted by introducing protective gas under vacuum to obtain an iron-cobalt-nickel-copper-aluminum-molybdenum alloy ingot, and the iron-cobalt-nickel-copper-aluminum-molybdenum alloy ingot is repeatedly smelted to obtain a high-entropy alloy soft magnetic material for the aerospace field.

[0012] The beneficial effect of taking the above further operation is: the alloy is smelted in batches according to the metallurgical characteristics of each component pure metal, based on the relatively good wettability of copper and molybdenum at high temperature, the copper block and the molybdenum block are first smelted to obtain a copper-molybdenum alloy ingot, and then the iron block, the cobalt block, the nickel block, and the aluminum block are smelted to obtain an iron-cobalt-nickel-aluminum alloy ingot.

[0013] Furthermore, in steps S1-S3, the vacuum degree during the smelting process is 3-3.6×10 -3 Pa.

[0014] Furthermore, in steps S1-S3, the protective gas is argon gas, the purity of the argon gas is 99.99wt%, and the pressure is 0.05-0.07MPa.

[0015] Further, in step S1, a water-cooled copper crucible is placed in an arc melting furnace and smelted for 45-65 seconds at a current of 480-500A.

[0016] Further, in step S2, a water-cooled copper crucible is placed in an arc melting furnace and smelted for 30-40 seconds at a current of 400-420A.

[0017] Further, in step S3, a water-cooled copper crucible is placed in an arc melting furnace and smelted for 45-65 seconds, and then smelted repeatedly for 7-9 times, each time for 45-65 seconds, with a current of 480-500A.

[0018] The beneficial effect of adopting the above further technical solution is that the melting point of the molybdenum-containing alloy is relatively high, so the molybdenum-containing alloy can be more fully melted by using a higher melting current.

[0019] Furthermore, in steps S1-S3, the voltage during smelting is 15-20V.

[0020] In summary, the present invention has the following beneficial effects:

[0021] 1. The high entropy alloy soft magnetic material for aerospace provided by the present invention mainly uses 6 elements of iron, cobalt, nickel, copper, aluminum and molybdenum to prepare the high entropy alloy soft magnetic material through a vacuum non-consumable arc melting furnace. Among them, iron, cobalt and nickel are ferromagnetic elements, so that the material has a higher saturation magnetization. The increase in aluminum content will cause the phase structure to change from FCC to BCC, and the crystal structure may change from cellular crystals to dendrites. The microhardness of the alloy increases gradually, showing a "cocktail effect", and the mechanical properties increase. Copper is conducive to the formation of FCC solid solution, which is concentrated in the intergranular region and may precipitate as a spherical copper-rich nanophase, resulting in high entropy alloys with excellent comprehensive mechanical properties. After the addition of molybdenum, the structure of the alloy is significantly refined, and the strength, hardness, plasticity and high temperature resistance are all improved, and the hysteresis loss is reduced.

[0022] 2. The high-entropy alloy soft magnetic material for the aerospace field provided by the present invention has a saturation magnetization intensity of up to 169.86emu / g, a coercive force of 27Oe, a compressive yield strength of 952.23MPa, and a compression plastic strain of 100%. The higher plasticity is conducive to the subsequent processing of the material so that it can be applied in the aerospace, aviation and military fields. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 Fe 40.83 Co 40.81 Ni 10.20 Al 3.06 Cu 2.04 Mo 3.06 XRD patterns of high entropy alloy soft magnetic materials;

[0024] Figure 2 Fe 40.83 Co 40.81 Ni 10.20 Al 3.06 Cu 2.04 Mo 3.06 Compressive stress-strain curve of high entropy alloy soft magnetic materials;

[0025] Figure 3 Fe 40.83 Co 40.81 Ni 10.20 Al 3.06 Cu 2.04 Mo 3.06 Hysteresis loop diagram of high entropy alloy soft magnetic material. DETAILED DESCRIPTION

[0026] The present invention is further described below in conjunction with the embodiments and drawings, but the present invention is not limited thereto.

[0027] Example 1

[0028] A high entropy alloy soft magnetic material for the aerospace field includes the following raw materials in atomic percentage: 40.83% iron, 40.81% cobalt, 10.20% nickel, 2.04% copper, 3.06% aluminum and 3.06% molybdenum.

[0029] The method for preparing the high entropy alloy soft magnetic material for the aerospace field comprises the following steps:

[0030] S1. Take pure metal blocks of iron, cobalt, nickel, copper, aluminum and molybdenum, remove the surface oxide scale with a small grinding gun, and clean them with an ultrasonic cleaner. First, put the copper block and the molybdenum block into a water-cooled copper crucible in the arc melting furnace, close the door of the vacuum melting furnace, and evacuate the furnace chamber to a high vacuum state with a vacuum degree of 3.6×10 -3 Pa, then introduce high-purity argon gas with a purity of 99.99wt% as a protective gas, introduce argon gas until the pressure indication is above 0, the pressure is 0.06MPa, repeat the pumping-filling four times, under the protection of high-purity argon gas, adjust the tungsten electrode to 2mm away from the metal to start the arc, after the arc is successfully started, gradually increase the current to 500A, and adjust the distance from the tungsten electrode to the metal to 7mm, smelt for 55s, and obtain the copper-molybdenum alloy ingot;

[0031] S2. Put the iron block, cobalt block, nickel block and aluminum block into the water-cooled copper crucible of the arc melting furnace, close the door of the vacuum melting furnace, and evacuate the furnace chamber to a high vacuum state with a vacuum degree of 3.6×10 -3 Pa, and then high-purity argon is introduced as a protective gas. Argon is introduced until the pressure display is above 0, and the pressure is 0.06MPa. The pumping and filling are repeated four times. Under the protection of high-purity argon, the tungsten electrode is adjusted to 2mm away from the metal for arc striking. After the arc is successfully struck, the current is gradually increased to 400A, and the distance from the tungsten electrode to the metal is adjusted to 7mm. The smelting is performed for 35s to obtain an iron-cobalt-nickel-aluminum alloy ingot.

[0032] S3, placing the copper-molybdenum alloy ingot obtained in step S1 and the iron-cobalt-nickel-aluminum alloy ingot obtained in step S2 into a water-cooled copper crucible of an arc melting furnace, closing the door of the vacuum melting furnace, and evacuating the furnace chamber to a high vacuum state with a vacuum degree of 3.6×10 -3 Pa, and then high-purity argon is introduced as a protective gas. Argon is introduced until the pressure indication is above 0 and the pressure is 0.06MPa. The pumping and filling are repeated four times. Under the protection of high-purity argon, the tungsten electrode is adjusted to a distance of 2mm from the metal for arc initiation. After the arc is successfully initiated, the current is gradually increased to 500A, and the distance from the tungsten electrode to the metal is adjusted to 7mm. The smelting is performed for 55s to obtain an iron-cobalt-nickel-copper-aluminum-molybdenum alloy ingot. The iron-cobalt-nickel-copper-aluminum-molybdenum alloy ingot is repeatedly smelted for 8 times, each time for 50s, to obtain a high-entropy alloy soft magnetic material used in the aerospace field, namely Fe 40.83 Co 40.81 Ni 10.20 Al 3.06 Cu 2.04 Mo 3.06 .

[0033] Example 2

[0034] A high entropy alloy soft magnetic material used in the aerospace field includes the following raw materials in atomic percentage: 45% iron, 45% cobalt, 5% nickel, 1% copper, 2% aluminum and 2% molybdenum.

[0035] The method for preparing the high entropy alloy soft magnetic material for the aerospace field comprises the following steps:

[0036] S1. Take pure metal blocks of iron, cobalt, nickel, copper, aluminum and molybdenum, remove the surface oxide scale with a small grinding gun, and clean them with an ultrasonic cleaner. First, put the copper block and the molybdenum block into a water-cooled copper crucible in the arc melting furnace, close the door of the vacuum melting furnace, and evacuate the furnace chamber to a high vacuum state with a vacuum degree of 3.6×10 -3 Pa, then introduce high-purity argon gas with a purity of 99.99wt% as a protective gas, introduce argon gas until the pressure indication is above 0, the pressure is 0.05MPa, repeat the pumping-filling four times, under the protection of high-purity argon gas, adjust the tungsten electrode to 2mm away from the metal to start the arc, after the arc is successfully started, gradually increase the current to 480A, and adjust the distance from the tungsten electrode to the metal to 6mm, smelt for 45s, and obtain the copper-molybdenum alloy ingot;

[0037] S2. Put the iron block, cobalt block, nickel block and aluminum block into the water-cooled copper crucible of the arc melting furnace, close the door of the vacuum melting furnace, and evacuate the furnace chamber to a high vacuum state with a vacuum degree of 3.6×10 -3Pa, and then high-purity argon is introduced as a protective gas. Argon is introduced until the pressure display is above 0, and the pressure is 0.05MPa. The pumping and filling are repeated four times. Under the protection of high-purity argon, the tungsten electrode is adjusted to 2mm away from the metal for arc striking. After the arc is successfully struck, the current is gradually increased to 420A, and the distance from the tungsten electrode to the metal is adjusted to 6mm. The smelting is performed for 30s to obtain an iron-cobalt-nickel-aluminum alloy ingot.

[0038] S3, placing the copper-molybdenum alloy ingot obtained in step S1 and the iron-cobalt-nickel-aluminum alloy ingot obtained in step S2 into a water-cooled copper crucible of an arc melting furnace, closing the door of the vacuum melting furnace, and evacuating the furnace chamber to a high vacuum state with a vacuum degree of 3.6×10 -3 Pa, and then high-purity argon is introduced as a protective gas. Argon is introduced until the pressure indication is above 0 and the pressure is 0.05MPa. The pumping and filling are repeated four times. Under the protection of high-purity argon, the tungsten electrode is adjusted to 2mm away from the metal for arc initiation. After the arc is successfully initiated, the current is gradually increased to 480A, and the distance from the tungsten pole to the metal is adjusted to 6mm. The smelting is performed for 45s to obtain an iron-cobalt-nickel-copper-aluminum-molybdenum alloy ingot. The iron-cobalt-nickel-copper-aluminum-molybdenum alloy ingot is repeatedly smelted for 7 times, each time for 45s, to obtain a high-entropy alloy soft magnetic material used in the aerospace field, namely Fe 45 Co 45 Ni5Al2Cu1Mo2.

[0039] Example 3

[0040] A high entropy alloy soft magnetic material used in the aerospace field includes the following raw materials in atomic percentage: 15% iron, 15% cobalt, 20% nickel, 10% copper, 20% aluminum and 20% molybdenum.

[0041] The method for preparing the high entropy alloy soft magnetic material for the aerospace field comprises the following steps:

[0042] S1. Take pure metal blocks of iron, cobalt, nickel, copper, aluminum and molybdenum, remove the surface oxide scale with a small grinding gun, and clean them with an ultrasonic cleaner. First, put the copper block and the molybdenum block into a water-cooled copper crucible in the arc melting furnace, close the door of the vacuum melting furnace, and evacuate the furnace chamber to a high vacuum state with a vacuum degree of 3.6×10 -3 Pa, and then introduce high-purity argon gas with a purity of 99.99wt% as a protective gas, introduce argon gas until the pressure indication is above 0, the pressure is 0.07MPa, repeat the pumping-filling four times, under the protection of high-purity argon gas, adjust the tungsten electrode to 2mm away from the metal to start the arc, after the arc is successfully started, gradually increase the current to 490A, and adjust the distance from the tungsten electrode to the metal to 7mm, smelt for 65s, and obtain the copper-molybdenum alloy ingot;

[0043] S2. Put the iron block, cobalt block, nickel block and aluminum block into the water-cooled copper crucible of the arc melting furnace, close the door of the vacuum melting furnace, and evacuate the furnace chamber to a high vacuum state with a vacuum degree of 3.6×10 -3 Pa, and then high-purity argon is introduced as a protective gas. Argon is introduced until the pressure display is above 0, and the pressure is 0.07MPa. The pumping and filling are repeated four times. Under the protection of high-purity argon, the tungsten electrode is adjusted to 2mm away from the metal for arc striking. After the arc is successfully struck, the current is gradually increased to 410A, and the distance from the tungsten electrode to the metal is adjusted to 7mm. The smelting is performed for 40s to obtain an iron-cobalt-nickel-aluminum alloy ingot.

[0044] S3, placing the copper-molybdenum alloy ingot obtained in step S1 and the iron-cobalt-nickel-aluminum alloy ingot obtained in step S2 into a water-cooled copper crucible of an arc melting furnace, closing the door of the vacuum melting furnace, and evacuating the furnace chamber to a high vacuum state with a vacuum degree of 3.6×10 -3 Pa, and then high-purity argon is introduced as a protective gas. Argon is introduced until the pressure indication is above 0, and the pressure is 0.07MPa. The pumping and filling are repeated four times. Under the protection of high-purity argon, the tungsten electrode is adjusted to a distance of 2mm from the metal for arc initiation. After the arc is successfully initiated, the current is gradually increased to 490A, and the distance from the tungsten pole to the metal is adjusted to 7mm. The smelting is performed for 65s to obtain an iron-cobalt-nickel-copper-aluminum-molybdenum alloy ingot. The iron-cobalt-nickel-copper-aluminum-molybdenum alloy ingot is repeatedly smelted for 9 times, each time for 65s, to obtain a high-entropy alloy soft magnetic material used in the aerospace field, namely Fe 15 Co 15 Ni 20 Al 20 Cu 10 Mo 20 .

[0045] Test Example 1

[0046] The high entropy alloy soft magnetic material Fe prepared in Example 1 for use in the aerospace field 40.83 Co 40.81 Ni 10.20 Al 3.06 Cu 2.04 Mo 3.06 The high entropy alloy samples for testing were cut by electric spark wire cutting machine, and the high entropy alloy soft magnetic material Fe used in the aerospace field was obtained by XRD. 40.83 Co 40.81 Ni 10.20 Al 3.06 Cu 2.04 Mo 3.06 Conduct phase analysis, such as Figure 1 shown.

[0047] Depend on Figure 1It can be seen that the XRD analysis results show that the high entropy alloy soft magnetic material Fe used in the aerospace field 40.83 Co 40.81 Ni 10.20 Al 3.06 Cu 2.04 Mo 3.06 There are two phases in the molten metal: BCC and FCC.

[0048] Test Example 2

[0049] The high entropy alloy soft magnetic material Fe prepared in Example 1 for aerospace application was tested by a universal testing machine. 40.83 Co 40.81 Ni 10.20 Al 3.06 Cu 2.04 Mo 3.06 The compression performance test is performed, and the results are as follows Figure 2 shown.

[0050] Depend on Figure 2 It can be seen that the test results show that the high entropy alloy soft magnetic material Fe used in the aerospace field 40.83 Co 40.81 Ni 10.20 Al 3.06 Cu 2.04 Mo 3.06 The compressive yield strength is 952.23MPa, and the compressive plastic strain exceeds 100%, indicating that this high-entropy alloy soft magnetic material used in the aerospace field has very excellent plasticity and high strength.

[0051] Test Example 3

[0052] The high entropy alloy soft magnetic material Fe prepared in Example 1 for aerospace applications was subjected to VSM. 40.83 Co 40.81 Ni 10.20 Al 3.06 Cu 2.04 Mo 3.06 Conduct magnetic performance test, the results are as follows Figure 3 shown.

[0053] Depend on Figure 3 It can be seen that the saturation magnetization intensity of the high entropy alloy soft magnetic material used in the aerospace field is 169.86emu / g, and the coercive force is 27Oe, indicating that the high entropy alloy soft magnetic material used in the aerospace field has excellent soft magnetic properties.

[0054] In summary, the high entropy alloy soft magnetic material for aerospace field prepared by the method provided by the present invention has high strength and excellent plasticity and soft magnetic properties, and its excellent soft magnetic properties and mechanical properties can meet the requirements of aviation and aerospace fields for the performance of high entropy alloy soft magnetic materials.

[0055] Although the specific implementation of the present invention is described in detail in conjunction with the drawings, it should not be understood as limiting the scope of protection of this patent. Within the scope described in the claims, various modifications and variations that can be made by those skilled in the art without creative work still fall within the scope of protection of this patent.

Claims

1. A high entropy alloy soft magnetic material for aerospace field, characterized in that: It is composed of the following raw materials in atomic percentage: iron 40.83%, cobalt 40.81%, nickel 10.20%, copper 2.04%, aluminum 3.06% and molybdenum 3.06%.

2. The high entropy alloy soft magnetic material for aerospace field as claimed in claim 1, characterized in that: The iron, cobalt, nickel, copper, aluminum and molybdenum are single metal blocks, and the purity of the single metal blocks is 99.99wt.%.

3. The method for preparing a high entropy alloy soft magnetic material for aerospace field according to claim 1 or 2, characterized in that: The following steps are involved: S1, take a copper block and a molybdenum block, introduce a protective gas under a vacuum state, and smelt them to obtain a copper-molybdenum alloy ingot; S2, taking an iron block, a cobalt block, a nickel block and an aluminum block, introducing a protective gas under a vacuum state, and smelting to obtain an iron-cobalt-nickel-aluminum alloy ingot; S3. The copper-molybdenum alloy ingot obtained in step S1 and the iron-cobalt-nickel-aluminum alloy ingot obtained in step S2 are smelted by introducing protective gas under vacuum to obtain an iron-cobalt-nickel-copper-aluminum-molybdenum alloy ingot, and the iron-cobalt-nickel-copper-aluminum-molybdenum alloy ingot is repeatedly smelted to obtain a high-entropy alloy soft magnetic material for the aerospace field.

4. The method for preparing a high entropy alloy soft magnetic material for aerospace field as claimed in claim 3, characterized in that: In steps S1-S3, the vacuum degree during the smelting process is 3×10 -3 -3.6×10 -3 Pa.

5. The method for preparing a high entropy alloy soft magnetic material for aerospace field as claimed in claim 3, characterized in that: In steps S1-S3, the protective gas is argon gas, the purity of the argon gas is 99.99wt.%, and the pressure is 0.05-0.07MPa.

6. The method for preparing a high entropy alloy soft magnetic material for aerospace field as claimed in claim 3, characterized in that: In step S1, a water-cooled copper crucible is placed in an arc melting furnace and melted for 45-65 seconds at a current of 480-500A.

7. The method for preparing a high entropy alloy soft magnetic material for aerospace field as claimed in claim 3, characterized in that: In step S2, a water-cooled copper crucible is placed in an arc melting furnace and melted for 30-40 seconds at a current of 400-420A.

8. The method for preparing a high entropy alloy soft magnetic material for aerospace field as claimed in claim 3, characterized in that: In step S3, a water-cooled copper crucible is placed in an arc melting furnace and smelted for 45-65 seconds, and then smelted repeatedly for 7-9 times, each time for 45-65 seconds, with a current of 480-500A.

9. The method for preparing a high entropy alloy soft magnetic material for aerospace field as claimed in claim 3, characterized in that: In steps S1-S3, the voltage during smelting is 15-20V.

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