Undercooled solidification method for preparing amorphous nanocrystalline soft magnetic alloy with high iron content

Abstract

To provide an over-cooling coagulation method of preparation of a noncrystalline nanocrystal soft magnetic alloy of a high iron content, and provide a noncrystalline nanocrystal component.SOLUTION: An alloy to which over-cooling solidification is made is solidified rapidly to a band-like member or a powder by a rapid cooling method or a spray method of a molten material, and obtains a crystal alloy by a thermal treatment. A chemical formula of a noncrystalline nanocrystal alloy is FeSiBM. M is an element of one or more kinds of P, C, Nb, Mo, Zr, Hf, Mo, Y, Cu, and Co. In an atomic percentage of each alloy element, Fe is 80.0 to 89.0 at%, Si is 1.0 to 9.0 at%, B is 3.0 to 12.0 at%, P is 0 to 5.0 at%, C is 0 to 5.0 at%, Nb is 0 to 3.0 at%, Zr is 0 to 3.0 at%, Hf is 0 to 3.0 at%, Mo is 0 to 3.0 at%, Y is 0 to 5.0 at%, Cu is 0 to 2.0 at%, and Co is 0 to 16.0 at%, and a sum of them is 100%.SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to a method for preparing an amorphous nanocrystalline soft magnetic alloy with a high iron content by undercooling solidification, and belongs to the field of metal soft magnetic materials.

Background Art

[0002] Iron-based amorphous nanocrystalline soft magnetic alloys have great advantages such as low coercive force and high resistivity compared with crystalline soft magnetic alloys due to their special fine structure. However, since the saturation magnetization intensity decreases when a large amount of amorphous forming elements are present in the iron-based amorphous nanocrystalline soft magnetic alloy, it limits the development of high output and miniaturization of related soft magnetic components. A typical amorphous soft magnetic alloy (international symbol Metglas 2605SA1, Chinese symbol 1K101) with a saturation magnetization intensity of about 1.55 T and a typical nanocrystalline soft magnetic alloy (international symbol Finemet, Chinese symbol 1K107) with a saturation magnetization intensity of about 1.24 T are both much lower than the saturation magnetization intensity of silicon steel (about 2.12 T).

[0003] Regarding amorphous nanocrystalline soft magnetic alloys, in order to fully expand their potential uses in various electronic devices, it is urgent to increase the content of magnetic elements mainly composed of Fe and the saturation magnetization intensity in iron-based amorphous nanocrystalline soft magnetic alloys. The difficulty in preparing an amorphous nanocrystalline soft magnetic alloy with a high iron content lies in the strict requirements for obtaining an amorphous matrix, that is, the cooling rate of the molten alloy needs to reach 10 5 ℃ / S or more. According to the Inoue amorphous principle, it is always necessary to add about 20 at% of non-magnetic elements to the alloy to promote the formation of an amorphous structure. Nanocrystalline soft magnetic alloys are formed by crystallizing and annealing amorphous alloys, and in many cases, it is necessary to add non-magnetic elements that form crystal nuclei and suppress crystal grain growth. The introduction of these elements greatly limits the content of ferromagnetic elements in the amorphous nanocrystalline soft magnetic alloy, making it difficult to obtain a high saturation magnetization intensity.

[0004] Currently, the methods for increasing the saturation magnetization of iron-based amorphous nanocrystalline soft magnetic alloys mainly focus on component control. On the one hand, adding Co elements to enhance the ferromagnetic exchange strength in the alloy can increase the saturation magnetization of the alloy. For example, Patent ZL201410728540.1 discloses a nanocrystalline alloy with a saturation magnetization of 1.80 T by adding 6 - 20 at% Co, and the coercive force is in the range of 10 - 35 A / m. On the other hand, the amounts of metalloid elements such as Si, B, C, P, etc. are adjusted. For example, Patent ZL200510066862.5 states that when c is in the range of 12 - 18 at% and satisfies the condition of b ≤ (0.5×a - 36)×d, the saturation magnetization of the iron-based amorphous member may reach 1.60 T or more. TIFF0007704452000001.tif1062 alloy is disclosed. Moreover, Patent ZL201410285976.8 discloses a 1 / 3 TIFF0007704452000003.tif1084 alloy with the highest saturation magnetization of 1.69 T. These methods, on the one hand, according to the Inoue amorphous principle, adjust the addition ratio of metalloid elements to affect the mixing enthalpy of the alloy and the difference in atomic size, thereby improving the amorphous formation ability of the alloy and increasing the content of ferromagnetic elements. On the other hand, the 2p electrons of metalloid elements may affect the 3d electrons of Fe, and thus affect the magnitude of the magnetic moment of Fe atoms to adjust the saturation magnetization of the alloy. From the above patents, it can be seen that for the method of adjusting the content of metalloid elements, it is necessary to accurately control the proportional relationship of different elements, and the increase in the addition amount of ferromagnetic elements is still limited, which restricts further improvement of the saturation magnetization. TIFF0007704452000002.tif1044 alloy is disclosed. In addition, Patent ZL201410285976.8 discloses a TIFF0007704452000003.tif1084 alloy with the highest saturation magnetization of 1.69 T. TIFF0007704452000004.tif952 alloy is disclosed. These methods, on the one hand, according to the Inoue amorphous principle, adjust the addition ratio of metalloid elements to affect the mixing enthalpy of the alloy and the difference in atomic size, thereby improving the amorphous formation ability of the alloy and increasing the content of ferromagnetic elements. On the other hand, the 2p electrons of metalloid elements may affect the 3d electrons of Fe, and thus affect the magnitude of the magnetic moment of Fe atoms to adjust the saturation magnetization of the alloy. From the above patents, it can be seen that for the method of adjusting the content of metalloid elements, it is necessary to accurately control the proportional relationship of different elements, and the increase in the addition amount of ferromagnetic elements is still limited, which restricts further improvement of the saturation magnetization.

[0005] The present invention realizes undercooled solidification of an iron-based amorphous nanocrystalline soft magnetic alloy by combining glass purification with cyclic superheating or by using electromagnetic levitation melting, reduces the amount of non-magnetic elements added to the alloy, effectively increases the amount of ferromagnetic elements added to the alloy, enhances the saturation magnetization intensity of the alloy, and can maintain a low coercive force.

Summary of the Invention

Problems to be Solved by the Invention

[0006] The present invention overcomes the drawbacks of existing preparation techniques for iron-based amorphous nanocrystalline soft magnetic alloys. By means of an undercooled non-equilibrium solidification method, it reduces the amount of amorphous-forming elements added to the alloy, realizes the preparation of an amorphous nanocrystalline soft magnetic alloy with a high iron content, thereby expanding the design range of iron-based amorphous nanocrystalline soft magnetic alloys, and aims to increase the saturation magnetization intensity of the alloy.

Means for Solving the Problems

[0007] The technical solution adopted by the present invention is as follows: An undercooled solidification method for preparing a high-iron content amorphous nanocrystalline soft magnetic alloy that achieves the goal of increasing the saturation magnetization intensity and decreasing the coercive force by using a method of combining glass purification with cyclic superheating or electromagnetic levitation melting to undercool and solidify the alloy, reducing the amount of non-magnetic elements added to the iron-based amorphous nanocrystalline soft magnetic alloy, and increasing the proportion of Fe element.

[0008] Preferably, the method of combining the above-mentioned glass purification with cyclic superheating is as follows: S1. The chemical formula of the amorphous nanocrystalline alloy is FeSiBM, where M is one or more elements of P, C, Nb, Mo, Zr, Hf, Mo, Y, Cu, and Co; remove and wash the oxide film on the alloy raw materials, weigh the raw materials according to a specific mass ratio, load the weighed raw materials into a vacuum induction melting furnace or a vacuum arc melting furnace, and after the vacuum reaches 10 -3 Pa, introduce an inert gas to protect the melting, and repeat the melting 4 to 6 times to obtain an alloy ingot. S2. Put the alloy ingot into a crucible, cover its upper and lower surfaces with a glass purifying agent at a specific mass ratio, and ensure that the alloy ingot is completely wrapped by the glass purifying agent. S3. After the vacuum reaches 10 -2 Pa, introduce an inert gas to protect and heat the alloy to melt it, then raise the temperature to 1200 - 1500 °C, hold for 1 - 10 minutes, stop the heating power supply and let the alloy cool naturally. S4. Perform the "heating - holding - solidification" cyclic treatment 3 - 6 times to obtain the desired degree of supercooling for the alloy. S5. Rapidly solidify the alloy subjected to supercooling solidification into a strip - shaped member or powder by the rapid cooling method of the melt or the spraying method. S6. Anneal the obtained strip or powder to remove internal stress to obtain an iron - based amorphous alloy, or perform crystallization annealing to obtain an iron - based nanocrystalline alloy.

[0009] Preferably, the inert gas is argon or nitrogen with a purity of 99.9 vol% or more. Preferably, the heat - resistant temperature of the crucible is 1400 °C or more. Preferably, the preparation process of the glass purifying agent is to weigh powders TIFF0007704452000005.tif1052 respectively and place them in a high - purity steel ball crucible, bake at 400 - 600 °C for 1 - 8 hours, then perform melting and baking at 800 - 1000 °C for 2 - 16 hours. After baking, TIFF0007704452000006.tif1052 are mixed to obtain a purifying agent, and the mass ratio of both is 1:1 - 20. Preferably, the mass ratio of the glass purifying agent to the alloy ingot is 1:1 - 5.

[0010] Preferably, the electromagnetic levitation melting method is S1. The chemical formula of the amorphous nanocrystalline alloy is FeSiBM, where M is one or more elements of P, C, Nb, Mo, Zr, Hf, Mo, Y, Cu, and Co; remove the oxide film on the alloy raw materials for cleaning, weigh the raw materials according to a specific mass ratio, load the weighed raw materials into a vacuum induction melting furnace or a vacuum arc melting furnace, after the vacuum reaches 10 -3 Pa, introduce an inert gas to protect and perform melting, repeat melting 4 to 6 times to obtain an alloy ingot, and S2. After the vacuum reaches 10 -3 Pa, introduce an inert gas for protection, send it below the coil from which the alloy ingot is hanging, and stably float the master alloy to the center of the heating coil under the action of the Lorentz force formed by the interaction between the electromagnetic field and the induced current; S3. Heat and melt the alloy by the induction of the heating coil, then raise the temperature to 1200 - 1500 °C, keep it warm for 1 - 10 minutes, and then stop the heating power supply to let the alloy cool naturally; S4. Perform the "heating - holding - solidification" cyclic treatment 3 to 6 times to enable the alloy to obtain a desired degree of supercooling; S5. Solidify the alloy subjected to supercooling solidification into a strip - shaped member or powder by the rapid cooling method of the melt or the spraying method; S6. It includes stress relieving or annealing for crystallization of the obtained strip - shaped member or powder to obtain an iron - based nanocrystalline alloy.

[0011] Preferably, the chemical formula of the high - iron - content amorphous nanocrystalline soft magnetic alloy is FeSiBM, where M is one or more elements of P, C, Nb, Mo, Zr, Hf, Mo, Y, Cu, and Co, and the atomic percentage of each alloy element is: Fe is 80.0 - 89.0 at%, Si is 1.0 - 9.0 at%, B is 3.0 - 12.0 at%, P is 0 - 5.0 at%, C is 0 - 5.0 at%, Nb is 0 - 3.0 at%, Zr is 0 - 3.0 at%, Hf is 0 - 3.0 at%, Mo is 0 - 3.0 at%, Y is 0 - 5.0 at%, Cu is 0 - 2.0 at%, Co is 0 - 16.0 at%, and the total is 100%.

[0012] Preferably, the inert gas is argon or nitrogen with a purity of 99.9 vol% or more. Preferably, the annealing of the amorphous alloy is within a temperature range of 50 to 100 °C below the crystallization temperature, and the annealing temperature of the nanocrystals is within a temperature range of 0 to 100 °C above the crystallization temperature. Preferably, the annealing is performed in an inert gas atmosphere or an atmosphere with a vacuum degree of 10 -1 Pa or less.

Advantages of the Invention

[0013] The amorphous nanocrystalline soft magnetic alloy prepared by the above non-equilibrium solidification method has a high amorphous formation ability, helps to reduce the amount of amorphous forming elements added to the alloy, and increase the content of ferromagnetic element Fe. The amorphous nanocrystalline soft magnetic alloy with a high iron content prepared by the above method has soft magnetic properties of high saturation magnetization intensity and low coercive force.

Embodiments for Carrying out the Invention

[0014] Next, we will explain the embodiments of the present invention in detail. By adjusting the alloy composition and degree of supercooling, an amorphous nanocrystalline soft magnetic alloy with a high iron content and high saturation magnetization intensity is obtained.

Examples

[0015] Example 1 Prepare an FeSiB amorphous alloy by the supercooled solidification method FeSiB-based alloys were prepared. Alloy 1 had an Fe content of 83.0 at%, an Si content of 8.0 at%, and a B content of 9.0 at%; Alloy 2 had an Fe content of 85.0 at%, an Si content of 7.0 at%, and a B content of 8.0 at%; Alloy 3 had an Fe content of 88.0 at%, an Si content of 3.0 at%, and a B content of 9.0 at%. S1. Remove and wash the oxide film of the alloy raw materials, and weigh the raw materials according to a specific mass ratio. Load the weighed raw materials into a vacuum arc melting furnace, and the degree of vacuum is 8×10 -4After reaching Pa, argon gas with a purity of 99.9 vol% is introduced to protect the melting, and melting is repeated 5 times to obtain an alloy ingot. S2. Put the alloy ingot into a crucible and cover its upper and lower surfaces with a mixed purified glass of TIFF0007704452000007.tif1052, and set the mass ratio of both to 1:5 so that the alloy ingot is completely wrapped by the glass purifying agent. S3. After the vacuum reaches 5×10 -3 Pa, argon gas with a purity of 99.9 vol% is introduced to protect and heat the alloy to melt it, then the temperature is raised to 1350 °C, held for 2 minutes, and the heating power supply is stopped to let the alloy cool naturally. S4. Perform the "heating - holding - solidification" cyclic treatment 4 times and 6 times respectively to obtain a degree of undercooling of about 190 °C and 260 °C for the alloy. S5. The alloy subjected to undercooling solidification is rapidly cooled through the melt and solidified into a strip - shaped member. S6. Anneal the obtained strip - shaped member at 300 °C to relieve stress to obtain an iron - based amorphous alloy.

[0016] The saturation magnetization and coercive force of the alloy at various degrees of undercooling are shown in the following table. Table 1 Saturation magnetization and coercive force of FeSiB - based amorphous alloys at various degrees of undercooling JPEG0007704452000008.jpg191135

Example

[0017] Example 2 Prepare an FeSiBPC amorphous alloy by the undercooling solidification method It has been prepared that FeSiBPC-based alloys, in alloy 1, the Fe content is 84.0 at%, the Si content is 2.0 at%, the B content is 8.0 at%, the P content is 5.0 at%, and the C content is 1.0 at%; in alloy 2, the Fe content is 84.0 at%, the Si content is 2.0 at%, the B content is 8.0 at%, the P content is 1.0 at%, and the C content is 5.0 at%; in alloy 3, the Fe content is 89.0 at%, the Si content is 2.0 at%, the B content is 8.0 at%, the P content is 0.5 at%, and the C content is 0.5 at%. S1. Remove and wash the oxide film of the alloy raw materials, and weigh the raw materials according to a specific mass ratio. Load the weighed raw materials into a vacuum arc melting furnace. After the degree of vacuum reaches 7×10 -4 Pa, introduce nitrogen gas with a purity of 99.9 vol% to protect the melting, and repeat the melting 6 times to obtain an alloy ingot. S2. Put the alloy ingot into a crucible, and cover its upper and lower surfaces with a mixed purified glass of TIFF0007704452000009.tif1052. When the mass ratio of both is 1:4, completely wrap the alloy ingot with the glass purifying agent. S3. After the degree of vacuum reaches 4×10 -3 Pa, introduce nitrogen gas with a purity of 99.9 vol% to protect the alloy and heat it to melt, then raise the temperature to 1400 °C, keep it warm for 3 minutes, turn off the heating power supply, and let the alloy cool naturally. S4. Perform the "heating - heat preservation - solidification" cyclic treatment 4 times and 6 times respectively, so as to obtain supercooling degrees of about 160 °C and 255 °C for the alloy. S5. The alloy subjected to supercooling solidification is rapidly cooled through the melt and solidified into a strip-shaped member. S6. Anneal the obtained strip-shaped member at 300 °C to relieve stress to obtain an iron-based amorphous alloy.

[0018] The saturation magnetization intensity and coercive force of the alloy at various supercooling degrees are shown in the following table. Table 2 Saturation magnetization intensity and coercive force of FeSiBPC-based amorphous alloys at various supercooling degrees JPEG0007704452000010.jpg191135

Example

[0019] Example 3 Prepare the FeSiBC amorphous alloy by the undercooling solidification method FeSiBC-based alloys were prepared. For alloy 1, the Fe content is 84.0 at%, the Si content is 2.0 at%, the B content is 8.0 at%, and the C content is 6.0 at%. For alloy 2, the Fe content is 85.0 at%, the Si content is 2.0 at%, the B content is 8.0 at%, and the C content is 5.0 at%. For alloy 3, the Fe content is 89.0 at%, the Si content is 2.0 at%, the B content is 8.0 at%, and the C content is 1.0 at%. S1. Remove and wash the oxide film on the alloy raw materials, and weigh the raw materials according to a specific mass ratio. Load the weighed raw materials into a vacuum induction melting furnace or a vacuum arc melting furnace. After the vacuum reaches 8×10 -4 Pa, introduce an inert gas for protection and perform melting, and repeat melting 6 times to obtain an alloy ingot. S2. After the vacuum reaches 4×10 -3 Pa, introduce nitrogen gas with a purity of 99.9 vol% for protection, send it below the coil where the alloy ingot is hanging, and stably float the master alloy to the center of the heating coil under the action of the Lorentz force formed by the interaction between the electromagnetic field and the induced current. S3. Heat and melt the alloy by the induction of the heating coil, then raise the temperature to 1500°C, keep it warm for 5 minutes, and stop the heating power supply to let the alloy cool naturally. S4. Perform the "heating-holding-solidification" cyclic treatment 3 times and 5 times respectively to obtain a degree of undercooling of about 150°C and 225°C for the alloy. S5. The alloy subjected to undercooling solidification is rapidly cooled through the melt and solidified into a strip-shaped member. S6. Anneal the obtained strip-shaped member at 300°C for crystallization to obtain an iron-based amorphous alloy.

[0020] The saturation magnetization and coercive force of the alloy at various degrees of undercooling are shown in the following table. Table 3 Saturation magnetization and coercive force of FeSiBC amorphous alloy at various degrees of undercooling JPEG0007704452000011.jpg191135

Example

[0021] Example 4 Prepare FeSiBCu nanocrystalline alloy by undercooling solidification method FeSiBCu-based alloys were prepared. For alloy 1, the Fe content is 80.5 at%, the Si content is 7.0 at%, the B content is 12.0 at%, and the Cu content is 0.5 at%; for alloy 2, the Fe content is 85.0 at%, the Si content is 2.5 at%, the B content is 12.0 at%, and the Cu content is 0.5 at%; for alloy 3, the Fe content is 85.0 at%, the Si content is 1.2 at%, the B content is 12.0 at%, and the Cu content is 1.8 at%. S1. Remove and wash the oxide film on the alloy raw materials, and weigh the raw materials according to a specific mass ratio. Load the weighed raw materials into a vacuum induction melting furnace. After the vacuum reaches 9×10 -4 Pa, introduce argon gas with a purity of 99.9 vol% to protect the melting, and repeat the melting 4 times to obtain an alloy ingot. S2. Put the alloy ingot into a crucible, and cover its upper and lower surfaces with a mixture of purified glass of TIFF0007704452000012.tif1052, and when the mass ratio of both is 1:20, make the alloy ingot completely wrapped by the glass purifier. S3. After the vacuum reaches 5×10 -3 Pa, introduce argon gas with a purity of 99.9 vol% to protect the heating and melting of the alloy, then raise the temperature to 1320°C, keep it warm for 5 minutes, stop the heating power supply, and let the alloy cool naturally. S4. Perform the "heating-holding-solidification" cyclic treatment 3 times and 4 times respectively to obtain an undercooling degree of about 205°C and 255°C for the alloy. S5. The alloy subjected to undercooling solidification is rapidly cooled through the melt and solidified into a strip-shaped member. S6. The obtained strip-shaped member is annealed at 450 °C to relieve stress to obtain an iron-based nanocrystalline alloy.

[0022] The saturation magnetization and coercive force of the alloy at various degrees of undercooling are shown in the following table. Table 4 Saturation magnetization and coercive force of FeSiBCu-based nanocrystalline alloys at various degrees of undercooling JPEG0007704452000013.jpg191135

Example

[0023] Example 5 Prepare an FeSiBNbCu nanocrystalline alloy by the undercooling solidification method It is found that an FeSiBNbCu-based alloy is prepared. In alloy 1, the Fe content is 80.0 at%, the Si content is 7.0 at%, the B content is 9.0 at%, the Nb content is 3.0 at%, and the Cu content is 1.0 at%; in alloy 2, the Fe content is 82.0 at%, the Si content is 6.0 at%, the B content is 9.0 at%, the Nb content is 2.0 at%, and the Cu content is 1.0 at%; in alloy 3, the Fe content is 85.0 at%, the Si content is 4.5 at%, the B content is 9.0 at%, the Nb content is 0.5 at%, and the Cu content is 1.0 at%. S1. Remove the oxide film of the alloy raw materials, wash them, and weigh the raw materials according to a specific mass ratio. The weighed raw materials are loaded into a vacuum arc melting furnace. After the degree of vacuum reaches 8×10 -4 Pa, argon gas with a purity of 99.9 vol% is introduced to protect the melting, and melting is repeated 6 times to obtain an alloy ingot. S2. Put the alloy ingot into a crucible and cover its upper and lower surfaces with a purified glass mixture of TIFF0007704452000014.tif1052, and when the mass ratio of both is 1:10, the alloy ingot is completely wrapped by the glass purifying agent. S3. When the degree of vacuum reaches 8×10 -3After reaching Pa, nitrogen gas with a purity of 99.9 vol% is introduced to protect and heat the alloy to melt it. Subsequently, the temperature is raised to 1380 °C, held for 1 minute, and then the heating power supply is turned off to allow the alloy to cool naturally. S4. Perform the "heating - holding - solidification" cyclic process 5 times and 6 times respectively to obtain supercooling degrees of about 190 °C and 225 °C in the alloy. S5. The alloy subjected to supercooled solidification is rapidly cooled through the melt and solidified into a strip - shaped member. S6. Anneal the obtained strip - shaped member at 550 °C to relieve stress to obtain an iron - based nanocrystalline alloy.

[0024] The saturation magnetization and coercive force of the alloy at various supercooling degrees are shown in the following table. Table 5 Saturation magnetization and coercive force of FeSiBNbCu - based nanocrystalline alloy at various supercooling degrees JPEG0007704452000015.jpg191135

Example

[0025] Example 6 Prepare FeSiBMoCu nanocrystalline alloy by the supercooled solidification method FeSiBMoCu - based alloys were prepared. For alloy 1, the Fe content is 80.0 at%, the Si content is 7.0 at%, the B content is 9.0 at%, the Mo content is 3.0 at%, and the Cu content is 1.0 at%; for alloy 2, the Fe content is 82.0 at%, the Si content is 6.0 at%, the B content is 9.0 at%, the Mo content is 2.0 at%, and the Cu content is 1.0 at%; for alloy 3, the Fe content is 83.3 at%, the Si content is 5.0 at%, the B content is 9.0 at%, the Mo content is 0.7 at%, and the Cu content is 1.0 at%. S1. Remove and wash the oxide film of the alloy raw materials, and weigh the raw materials according to a specific mass ratio. Load the weighed raw materials into a vacuum induction melting furnace, and the degree of vacuum is 8×10 -4After reaching Pa, argon gas with a purity of 99.9 vol% is introduced to protect the melting, and melting is repeated four times to obtain an alloy ingot. S2. Put the alloy ingot into a crucible, and cover its upper and lower surfaces with a mixed purified glass of TIFF0007704452000016.tif1052. When the mass ratio of both is 1:1, the alloy ingot is completely wrapped by the glass purifying agent. S3. After the vacuum reaches 1×10 -2 Pa, argon gas with a purity of 99.9 vol% is introduced to heat and melt the alloy under its protection, then the temperature is raised to 1370 °C, held for 6 minutes, and the heating power supply is stopped to allow the alloy to cool naturally. S4. Perform the "heating - holding - solidification" cyclic treatment 3 times and 5 times respectively to obtain a supercooling degree of about 175 °C and 255 °C for the alloy. S5. The alloy subjected to supercooling solidification is rapidly cooled through the melt and solidified into a strip - shaped member. S6. The obtained strip - shaped member is annealed at 500 °C to relieve stress to obtain an iron - based nanocrystalline alloy.

[0026] The saturation magnetization and coercive force of the alloy at various supercooling degrees are shown in the following table. Table 6 Saturation magnetization and coercive force of FeSiBMoCu - based nanocrystalline alloy at various supercooling degrees JPEG0007704452000017.jpg191135

Example

[0027] Example 7 Prepare an FeCoSiBCCu nanocrystalline alloy by the supercooling solidification method It has been prepared that FeCoSiBCCu-based alloys, in alloy 1, the Fe content is 80.0 at%, the Co content is 5.0 at%, the Si content is 1.5 at%, the B content is 9.0 at%, the C content is 3.0 at%, and the Cu content is 1.5 at%; in alloy 2, the Fe content is 80.0 at%, the Co content is 5.0 at%, the Si content is 1.5 at%, the B content is 9.0 at%, the C content is 3.0 at%, and the Cu content is 1.5 at%; in alloy 3, the Fe content is 80.0 at%, the Co content is 5.0 at%, the Si content is 1.5 at%, the B content is 9.0 at%, the C content is 3.0 at%, and the Cu content is 1.5 at%. S1. Remove and wash the oxide film of the alloy raw materials, and weigh the raw materials according to a specific mass ratio. Load the weighed raw materials into a vacuum arc melting furnace. After the vacuum reaches 8×10 -4 Pa, put in argon gas with a purity of 99.9 vol% to protect the melting, and repeat the melting 5 times to obtain an alloy ingot. S2. Put the alloy ingot into a crucible, and cover its upper and lower surfaces with a mixed purified glass of TIFF0007704452000018.tif1052. When the mass ratio of both is 1:3, completely wrap the alloy ingot with the glass purifying agent. S3. After the vacuum reaches 8×10 -3 Pa, put in nitrogen gas with a purity of 99.9 vol% to protect and heat and melt the alloy, then raise the temperature to 1350 °C, keep it warm for 8 minutes, stop the heating power supply and let the alloy cool naturally. S4. Perform the "heating - heat preservation - solidification" cyclic treatment 3 times and 6 times respectively to obtain a supercooling degree of about 150 °C and 265 °C for the alloy. S5. The alloy subjected to supercooling solidification is rapidly cooled through the melt and solidified into a strip member. S6. Anneal the obtained strip member at 400 °C to relieve stress to obtain an iron-based nanocrystalline alloy.

[0028] The saturation magnetization and coercive force of the alloy at various supercooling degrees are shown in the following table. Table 7 Saturation magnetization and coercive force of FeCoSiBCCu-based nanocrystalline alloys at various degrees of supercooling JPEG0007704452000019.jpg191135

Example

[0029] Example 8 Prepare FeSiBZrHfCu nanocrystalline alloy by undercooling solidification method FeSiBZrHfCu-based alloys were prepared. In alloy 1, the Fe content is 80.0 at%, the Si content is 6.0 at%, the B content is 9.0 at%, the Zr content is 3.0 at%, the Hf content is 1.0 at%, and the Cu content is 1.0 at%; in alloy 2, the Fe content is 80.0 at%, the Si content is 6.0 at%, the B content is 9.0 at%, the Zr content is 1.0 at%, the Hf content is 3.0 at%, and the Cu content is 1.0 at%; in alloy 3, the Fe content is 87.0 at%, the Si content is 2.0 at%, the B content is 9.0 at%, the Zr content is 0.5 at%, the Hf content is 0.5 at%, and the Cu content is 1.0 at%. S1. Remove and wash the oxide film of the alloy raw materials, and weigh the raw materials according to a specific mass ratio. Load the weighed raw materials into a vacuum induction melting furnace or a vacuum arc melting furnace. After the vacuum reaches 8×10 -4 Pa, introduce an inert gas for protection and perform melting, and repeat melting 6 times to obtain an alloy ingot. S2. After the vacuum reaches 4×10 -3 Pa, introduce nitrogen gas with a purity of 99.9 vol% for protection, send it under the coil where the alloy ingot is hanging, and stably float the master alloy to the center of the heating coil under the action of the Lorentz force formed by the interaction between the electromagnetic field and the induced current. S3. Heat and melt the alloy by the induction of the heating coil, then raise the temperature to 1400°C, keep it warm for 10 minutes, stop the heating power supply, and let the alloy cool naturally. S4. Perform the "heating - holding - solidifying" cycle 4 times and 6 times respectively to allow the alloy to obtain supercooling degrees of about 210 °C and 270 °C. S5. The alloy subjected to supercooling solidification is rapidly cooled through the melt and solidified into a strip - shaped member. S6. Anneal the obtained strip - shaped member at 550 °C for crystallization to obtain an iron - based nanocrystalline alloy.

[0030] The saturation magnetization and coercive force of the alloy at various supercooling degrees are shown in the following table. Table 8 Saturation magnetization and coercive force of FeSiBZrHfCu - based nanocrystalline alloy at various supercooling degrees JPEG0007704452000020.jpg191135

Example

[0031] Example 9 Prepare an FeSiBYCu nanocrystalline alloy by the supercooling solidification method FeSiBYCu - based alloys were prepared. For alloy 1, the Fe content is 81.0 at%, the Si content is 4.0 at%, the B content is 9.0 at%, the Y content is 5.0 at%, and the Cu content is 1.0 at%; for alloy 2, the Fe content is 84.0 at%, the Si content is 4.0 at%, the B content is 9.0 at%, the Y content is 2.0 at%, and the Cu content is 1.0 at%; for alloy 3, the Fe content is 87.0 at%, the Si content is 2.0 at%, the B content is 9.0 at%, the Y content is 1.0 at%, and the Cu content is 1.0 at%. S1. Remove and wash the oxide film of the alloy raw materials, and weigh the raw materials according to a specific mass ratio. Load the weighed raw materials into a vacuum arc melting furnace. After the vacuum reaches 8×10 -4 Pa, introduce an inert gas to protect the melting and repeat the melting 4 times to obtain an alloy ingot. S2. When the vacuum reaches 5×10 -3After reaching Pa, argon gas with a purity of 99.9 vol% is introduced for protection, and it is sent below the coil from which the alloy ingot is suspended. Under the action of the Lorentz force formed by the interaction between the electromagnetic field and the induced current, the master alloy is stably floated to the center of the heating coil. S3. Heat and melt the alloy in response to the heating coil, then raise the temperature to 1500 °C and hold for 3 minutes, and turn off the heating power supply to let the alloy cool naturally. S4. Perform the "heating - holding - solidification" cyclic treatment 3 times and 6 times respectively to enable the alloy to obtain supercooling degrees of about 180 °C and 255 °C. S5. The alloy subjected to supercooled solidification is rapidly cooled through the melt and solidified into a strip - shaped member. S6. Anneal the obtained strip - shaped member at 500 °C for crystallization to obtain an iron - based nanocrystalline alloy.

[0032] The saturation magnetization intensity and coercive force of the alloy at various supercooling degrees are shown in the following table. Table 9 Saturation magnetization intensity and coercive force of FeSiBYCu - based nanocrystalline alloy at various supercooling degrees JPEG0007704452000021.jpg191135

[0033] In summary, the technical effect of the present invention is to improve the amorphous formation ability of iron-based alloys, reduce the content of amorphous formation elements, and increase the content of ferromagnetic elements by combining glass purification with cyclic overheating or by using electromagnetic levitation melting, thereby obtaining an amorphous nanocrystalline soft magnetic alloy having both high saturation magnetization intensity and low coercive force. The principle of achieving this technical effect is that in the process of combining glass purification with cyclic overheating, not only can the molten glass adsorb the heterogeneous nucleation sites of the molten alloy, but also the overheating and the hot and cold cycle of heating-holding-cooling can thermally decompose the heterogeneous nucleation sites at high temperature, causing mass exchange in the process of heat convection inside and on the surface, and effectively reducing the heterogeneous nucleation sites inside the alloy. In the process of electromagnetic levitation melting, containerless melting effectively avoids the introduction of impurities into the alloy during the melting process, and the high-temperature overheating thermally decomposes the heterogeneous nucleation sites inside the alloy. Both methods can reduce or avoid crystallization and improve the amorphous formation ability. On the one hand, reducing the heterogeneous nucleation sites can optimize the microstructure of the alloy, weaken the destructive effect on the magnetic exchange coupling effect, and increase the saturation magnetization intensity of the alloy. On the other hand, the improvement of the amorphous formation ability of the alloy promotes the formation of a more disordered amorphous structure, effectively eliminates the magnetic crystal anisotropy, and also reduces or avoids the obstacle of the heterogeneous nucleation sites to magnetic reversal, obtaining a low coercive force.

Claims

1. A supercooled solidification method for preparing an iron-based amorphous nanocrystalline soft magnetic alloy, which supercools and solidifies an alloy by using a method of combining glass purification with cyclic superheating, comprising: The method of combining the above-mentioned glass purification with cyclic superheating is as follows: S1. The chemical formula of the amorphous nanocrystalline alloy is FeSiBM, where M is one or more elements of P, C, Nb, Mo, Zr, Hf, Mo, Y, Cu and Co; Removing the oxide film on the alloy raw materials, washing them, weighing the raw materials according to a specific mass ratio, loading the weighed raw materials into a vacuum induction melting furnace or a vacuum arc melting furnace, after the degree of vacuum reaches 10-3 Pa, introducing an inert gas to protect the melting, repeating the melting 4 to 6 times to obtain an alloy ingot; S2. Putting the alloy ingot into a crucible, covering its upper and lower surfaces with a glass purifying agent in a specific mass ratio, and completely wrapping the alloy ingot with the glass purifying agent; S3. After the degree of vacuum reaches 10-2 Pa, introducing an inert gas to protect the alloy and heating it to melt, then raising the temperature to 1200-1500 °C, holding for 1-10 minutes, stopping the heating power supply and allowing the alloy to cool naturally; S4. Performing the "heating-holding-solidification" cyclic treatment 3 to 6 times to obtain a desired degree of supercooling for the alloy; S5. Rapidly solidifying the alloy subjected to supercooled solidification into a strip member or powder by a rapid cooling method or a spraying method of the melt; S6. Annealing the obtained strip or powder to remove internal stress to obtain an iron-based amorphous alloy, or performing crystallization annealing to obtain an iron-based nanocrystalline alloy. The supercooled solidification method is characterized by including the above steps.

2. The supercooled solidification method according to Claim 1, wherein the inert gas is argon or nitrogen with a purity of 99.9 vol% or more.

3. The supercooled solidification method according to Claim 1, wherein the heat-resistant temperature of the crucible is 1400 °C or higher.

4. The preparation process of the glass purifying agent involves weighing powder Na with a purity of 98% or more ２ B ４ O ７ and B ２ O ３ , placing them in high-purity steel crucibles respectively, firing at 400 - 600 °C for 1 - 8 hours, and then performing melting and firing at 800 - 1000 °C for 2 - 16 hours. The fired Na ２ B ４ O ７ and B ２ O ３ are mixed to obtain a purifying agent, and the mass ratio of both is 1:1 - 20 The supercooled solidification method according to Claim 1, characterized in that...

5. The supercooled solidification method according to Claim 1, wherein the mass ratio of the glass purifying agent to the alloy ingot is 1:1 to 5.

6. A supercooled solidification method for preparing an iron-based amorphous nanocrystalline soft magnetic alloy, which supercools and solidifies an alloy by using the method of electromagnetic suspension melting, comprising: The method of electromagnetic suspension melting is as follows: S1. The chemical formula of the amorphous nanocrystalline alloy is FeSiBM, where M is one or more elements of P, C, Nb, Mo, Zr, Hf, Mo, Y, Cu, and Co; Remove and wash the oxide film of the alloy raw material, weigh the raw materials according to a specific mass ratio, load the weighed raw materials into a vacuum induction melting furnace or a vacuum arc melting furnace, and after the degree of vacuum reaches 10 －３ Pa, introduce an inert gas to protect the melting, and repeat the melting 4 to 6 times to obtain an alloy ingot, S2. After the evacuation reaches 10 －３ Pa, an inert gas is introduced for protection, and it is sent below the coil from which the alloy ingot is hanging. Under the action of the Lorentz force formed by the interaction between the electromagnetic field and the induced current, the master alloy is stably floated to the center of the heating coil, and S3. Heat and melt the alloy under the induction of a heating coil, then raise the temperature to 1200 - 1500 °C, hold for 1 - 10 minutes, and then stop the heating power supply to let the alloy cool naturally; S4. Perform the "heating - holding - solidification" cyclic treatment 3 - 6 times to enable the alloy to obtain a desired degree of supercooling; S5. Solidify the alloy subjected to supercooled solidification into a strip - shaped member or powder by the rapid cooling method or spraying method of the melt; S6. Anneal the obtained strip - shaped member or powder to remove stress or crystallize it to obtain an iron - based nanocrystalline alloy A supercooled solidification method, characterized by including the above steps.

7. The chemical formula of the iron - based amorphous nanocrystalline soft magnetic alloy is FeSiBM, where M is one or more elements of P, C, Nb, Mo, Zr, Hf, Mo, Y, Cu, and Co. The atomic percentage of each alloy element is as follows: Fe is 80.0 - 89.0 at%, Si is 1.0 - 9.0 at%, B is 3.0 - 12.0 at%, P is 0 - 5.0 at%, C is 0 - 5.0 at%, Nb is 0 - 3.0 at%, Zr is 0 - 3.0 at%, Hf is 0 - 3.0 at%, Mo is 0 - 3.0 at%, Y is 0 - 5.0 at%, Cu is 0 - 2.0 at%, Co is 0 - 16.0 at%, and the total is 100%. The supercooled solidification method according to Claim 1 or 6, characterized by the above.

8. The supercooled solidification method according to Claim 6, characterized in that the inert gas is argon or nitrogen with a purity of 99.9 vol% or more.

9. The annealing of the amorphous alloy is within the temperature range of 50 - 100 °C below the crystallization temperature, and the annealing temperature of the nanocrystals is within the temperature range of 0 - 100 °C above the crystallization temperature. The supercooled solidification method according to Claim 6 is characterized by the above.

10. Annealing is carried out in an inert gas atmosphere or an atmosphere with a degree of vacuum of 10 －１ Pa or less, and the supercooled solidification method according to claim 9, characterized in that it is carried out in an atmosphere of Pa or less.

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