CN117626134A - High frequency and high magnetic permeability iron-based nanocrystalline alloy and preparation method thereof - Google Patents

Abstract

The invention discloses a high-frequency high-permeability iron-based nanocrystalline alloy and a preparation method thereof. The chemical formula of the alloy is FeaSibBcPdNBeCufM _g Wherein M is an impurity element, a-g is the atomic percentage content of each element, a+b+c+d+e+f+g=100, b is more than or equal to 15.5 and less than or equal to 20.5, and g is less than or equal to 0.5. The relative magnetic permeability of the iron-based nanocrystalline alloy at 100kHz is more than or equal to 29000. The preparation method of the alloy comprises the following steps: preparing raw materials according to the composition of the alloy, and sequentially smelting and heat-treating; at least part of the heat treatment is performed in a magnetic field. Compared with the prior art, the invention uses the P element to enhance the amorphous forming capability of the alloy, adopts the ultra-high Si content, can obtain the completely nanocrystalline strip under the existing preparation condition, and further prepares the nanocrystalline strip with high magnetic conductivity after heat treatment, and has simple process and low cost.

Description

High frequency and high magnetic permeability iron-based nanocrystalline alloy and preparation method thereof

Technical field

The invention relates to a nanocrystalline alloy, in particular to a high-frequency, high-permeability iron-based nanocrystalline alloy and a preparation method thereof, and belongs to the field of alloy materials.

Background technique

Since the nanocrystalline alloy was first developed in 1988, Fe _73.5 Si ₉ B _13.5 Nb ₃ Cu ₁ has been widely used. For decades, a large number of scientists and engineering technicians have done a lot of research work on this alloy. However, the current mainstream application is still the alloy composition.

As devices develop towards high frequencies, soft magnetic materials need to have good frequency stability and the magnetic permeability level with good frequency stability should be increased as much as possible. Currently, the process of preparing ultra-thin amorphous ribbons and applying transverse magnetic field heat treatment is commonly used. Meet the demand for soft magnetic materials for high-frequency devices. However, in order to meet the requirements of high magnetic permeability at high frequencies, the preparation process of ultra-thin amorphous ribbons needs to be continuously improved, and this solution will significantly increase the cost.

Research shows that increasing the Si content can lead to an increase in high-frequency magnetic permeability. By adjusting the Si content, nanocrystalline alloys with high silicon content will deteriorate the amorphous formation ability, making it difficult to prepare completely amorphous materials using existing processes. structure, subsequent performance cannot be guaranteed at all. It is usually necessary to increase the content of strong amorphous-forming elements such as Nb, Mo, and Cr to ensure that completely amorphous fast-quenching strips can be prepared under the existing process. Studies have also shown that adding Co and Ni elements can also be used to improve frequency stability, but this method will bring about a significant reduction in cost and may even significantly reduce low-frequency magnetic permeability, so this method is rarely used.

However, adding elements such as Co, Ni, Nb, and Mo usually requires a significant increase in the cost of raw materials. Without a significant improvement in performance, it is difficult to be promoted and applied. Therefore, there is an urgent need for a high-frequency and high-permeability nanocrystalline alloy that does not increase costs and is adaptable to current processes to meet the requirements for high magnetic permeability at high frequencies.

Contents of the invention

The main purpose of the present invention is to provide a high-frequency and high-permeability iron-based nanocrystalline alloy and a preparation method thereof to overcome the shortcomings of the existing technology.

In order to achieve the foregoing invention objectives, the technical solutions adopted by the present invention include:

One aspect of the present invention provides a high-frequency, high-permeability iron-based nanocrystalline alloy whose chemical formula is Fe _a Si _b B _c P _d Nb _e Cu _f M _g , where M is an impurity element, a, b, c , d, e, f and g are the atomic percentage contents of each element, a+b+c+d+e+f+g=100, and 15.5≤b≤20.5, g≤0.5.

Further, 70≤a≤75, 3≤c≤8, 0.5≤d≤5, 1.5≤e≤3.5, 0.5≤f≤1.5.

Among them, since there are many types of impurity elements, in order to facilitate the calculation of the content of impurity elements, the mass fraction of impurity elements and the atomic weight of Fe element are converted into Mg.

Further, the relative magnetic permeability of the iron-based nanocrystalline alloy at 100KHz is ≥29,000.

Another aspect of the present invention also provides a method for preparing the high-frequency high magnetic permeability iron-based nanocrystalline alloy, which includes: preparing raw materials according to the composition of the iron-based nanocrystalline alloy, and sequentially performing smelting and heat treatment , thereby preparing the iron-based nanocrystalline alloy; wherein at least part of the heat treatment is performed in a magnetic field.

Further, the intensity of the magnetic field is 0.01~1T. Preferably, the magnetic field is a constant magnetic field.

Further, the source of the magnetic field includes a permanent magnet or an electromagnet, that is, the magnetic field can be applied by a permanent magnet or an electromagnet.

Further, the heat treatment includes: first performing a first-stage heat treatment at 460-480°C for a time of 30-120 min; and then performing a second-stage heat treatment at 540-580°C for a time of 90-180 min.

In some cases, the entire heat treatment process is performed in the magnetic field. In other cases, the second stage heat treatment is performed in the magnetic field. But at least the second stage heat treatment needs to be carried out in the magnetic field.

In one embodiment, the preparation method specifically includes: smelting the raw material into an alloy liquid, processing it into a strip, and then subjecting the strip to the heat treatment to prepare the iron-based nanocrystals. alloy.

In one embodiment, the preparation method specifically includes the steps of batching, smelting, spraying tape, winding iron core, heat treatment, etc., namely:

First, raw materials are prepared according to the composition of the nanocrystalline alloy. The raw materials include metal elements or master alloys.

The obtained raw materials are used to form alloys through arc, induction, resistance furnace smelting, etc., which can be smelted in a vacuum or in a non-vacuum manner. Non-vacuum smelting requires melt purification to reduce harmful impurity elements or inclusion bands. After smelting, a uniformly mixed alloy liquid is formed. The alloy liquid can be directly used for strip making, or it can be cooled to form an alloy ingot, and then the alloy ingot is melted into alloy liquid and used for strip making.

The alloy liquid is then subjected to planar flow casting to obtain straight strips, and the XRD method can be used to detect whether the physical phase state of the strips is completely amorphous, and the strips are collected for later use. The belt spinning machine can be a gravity or pressure single roller belt spinning machine.

The collected strips can be rolled according to the required size and made into magnetic cores of corresponding sizes. The magnetic cores need to be fixed by spot welding or other methods to prevent the magnetic cores from spreading.

The magnetic core can obtain a nanocrystalline magnetic core with excellent performance after transverse magnetic field heat treatment. The treatment process is magnetic field heat treatment. The magnetic field can be applied by permanent magnets or electromagnets.

Compared with the existing technology, the present invention has at least the following advantages:

(1) The present invention significantly improves the high-frequency magnetic permeability of the alloy by increasing the Si content in the iron-based nanocrystalline alloy to 15.5~20.5at.%, reaching a magnetic permeability of ≥29000 at 100kHz, and by adding P element, effectively enhances the amorphous formation ability, overcomes defects such as insufficient amorphous formation ability caused by increased Si content, and makes the frequency attenuation resistance of the alloy good. Compared with adding Co, Ni, Nb, Mo and other elements to improve the alloy The high-frequency magnetic permeability method has lower cost.

(2) The high-frequency high-permeability iron-based nanocrystalline alloy of the present invention can be mass-produced under existing production conditions. It only needs to prepare raw materials according to the composition of the nanocrystalline alloy and carry out smelting and other processes. By preparing a completely amorphous strip, such as a strip with a specification of 21±1 microns, and then winding it into a magnetic core, and then heat treating it in a magnetic field, the corresponding nanocrystalline magnetic core can be obtained. Compared with the 107 alloy with high Si content, the preparation method of the present invention not only improves the high-frequency magnetic permeability of the iron-based nanocrystalline alloy, but also improves the amorphous formation ability of the iron-based nanocrystalline alloy. It is also consistent with the ultra-thin ribbon prepared by the pressure method. In comparison, the production process is easier and the cost can be greatly reduced while the performance is close.

Description of drawings

The present invention will be described in further detail below with reference to the accompanying drawings and specific embodiments.

Figure 1 is the XRD detection pattern of the iron-based nanocrystalline alloy quenched strip in the Examples and Comparative Examples of the present invention.

Detailed ways

As mentioned above, in view of the urgent demand for high-frequency and high-permeability nanocrystalline alloys in practical applications, the present invention is based on Fe _73.5 Si ₉ B _13.5 Nb ₃ Cu ₁ by greatly increasing the Si content and adding the remaining Adding P element to the alloy ensures that completely amorphous strips can be prepared under existing process conditions. After the strips are heat treated in a transverse magnetic field, the magnetic permeability can be ensured to be good at high frequencies. The addition of P can also follow the Nb and Cu cooperate to refine the nanocrystal grains, thus ensuring soft magnetic properties under high-frequency conditions, highlighted by magnetic permeability ≥ 29000 (at 100kHz).

The technical solution of the present invention will be further described below with reference to several embodiments.

In the following embodiments, an impedance analyzer is mainly used to test the inductance of the magnetic core at different frequencies, and its corresponding magnetic permeability is calculated based on its size, quality, etc.

Example 1 This example provides a method for preparing a high-frequency, high-permeability iron-based nanocrystalline alloy, which includes the following steps:

Use metal elements Fe, Si, Cu and intermediate alloys FeB, FeP, FeNb to weigh and batch the alloy components to obtain Fe ₇₀ Si _20.5 B ₄ P ₄ Nb ₂ Cu _0.5 for later use.

The obtained raw materials are used to form an alloy through vacuum smelting through arc smelting. The melt is purified to reduce the harm caused by harmful impurity elements or inclusions. After smelting, a uniformly mixed alloy liquid is formed, which can be directly used for belt making. During the strip making process, the casting temperature of the alloy liquid is controlled between 1310 and 1330°C. The alloy liquid is passed through a pressure single-roller belt spinning machine to obtain a straight strip. The XRD method is used to detect whether the physical phase state of the strip is completely amorphous. status, collect the strips for later use.

The collected strips are cut to the required size and then rolled to make a circular magnetic core with an outer diameter of 30mm, an inner diameter of 20mm, and a height of 10mm. The inner and outer layers of the core are fixed by spot welding or other methods. , to prevent the core from spreading.

After the magnetic core is subjected to transverse magnetic field heat treatment, a nanocrystalline magnetic core with excellent performance can be obtained. The treatment process is magnetic field heat treatment. The magnetic field is applied by an electromagnet. The magnetic field intensity is 0.1T and is applied during the entire two-stage heat treatment process. . The first stage of heat treatment is 460°C heat treatment for 120 minutes, and the second stage heat treatment is 540°C heat treatment with heat preservation for 180 minutes.

The inductance of the magnetic core obtained in this embodiment at different frequencies can be tested using an impedance analyzer. Calculation shows that its relative magnetic permeability at 100 kHz is 34100.

Example 2 This example provides a method for preparing a high-frequency, high-permeability iron-based nanocrystalline alloy, which includes the following steps:

Use metal elements Fe, Si, Cu and intermediate alloys FeB, FeP, FeNb to weigh and batch the alloy components to obtain Fe _71.5 Si ₁₉ B ₃ P _2.75 Nb ₃ Cu _0.75 for later use.

The raw materials obtained can be smelted by non-vacuum induction methods, and the melt can be purified to reduce the harm caused by harmful impurity elements or inclusions. After smelting, a uniformly mixed alloy liquid can be formed, and the alloy liquid can be directly used for belt making.

During the strip making process, the casting temperature of the alloy liquid is controlled to be between 1330 and 1350°C. The alloy liquid is made into a straight strip by gravity strip making, and the XRD method is used to detect whether the physical phase state of the strip is completely amorphous. Collect the strips and set aside for later use.

The collected strips are cut and rolled according to the required size, and can be made into a circular magnetic core with an outer diameter of 30mm, an inner diameter of 20mm, and a height of 10mm. The inner and outer layers of the core are spot welded or otherwise. Secure to prevent the core from unraveling.

After the magnetic core is subjected to transverse magnetic field heat treatment, a nanocrystalline magnetic core with excellent performance can be obtained. The treatment process is magnetic field heat treatment. The magnetic field is applied by an electromagnet. The magnetic field intensity is 1T, which is applied during the entire two-stage heat treatment process. The first stage of heat treatment is 470°C heat treatment for 60 minutes, and the second stage heat treatment is 560°C heat treatment with heat preservation for 150 minutes.

The inductance of the magnetic core obtained in this embodiment at different frequencies can be tested using an impedance analyzer. Calculation shows that its relative magnetic permeability at 100 kHz is 32,400.

Example 3 This example provides a method for preparing a high-frequency, high-permeability iron-based nanocrystalline alloy, which includes the following steps:

Use metal elements Fe, Si, Cu and master alloys FeB, FeP, FeNb to weigh and batch the alloy components to obtain Fe _73.5 Si ₁₇ B _4.25 P ₂ Nb ₂ Cu _1.25 for later use.

The obtained raw materials are smelted in a non-vacuum manner, and the melt is purified to reduce the harm caused by harmful impurity elements or inclusions. After smelting, a uniformly mixed alloy liquid is formed, and the alloy liquid is directly used for belt making. During the strip making process, the casting temperature of the alloy liquid is controlled between 1370 and 1390°C. The alloy liquid is passed through a gravity single-roller strip machine to obtain a straight strip. The XRD method is used to detect whether the physical phase state of the strip is completely amorphous. status, collect the strips for later use.

The collected strips are cut to the required size and then rolled to make a circular magnetic core with an outer diameter of 30mm, an inner diameter of 20mm, and a height of 10mm. The inner and outer layers of the core are fixed by spot welding or other methods. , to prevent the core from spreading.

The magnetic core can obtain a nanocrystalline magnetic core with excellent performance after transverse magnetic field heat treatment. The treatment process is magnetic field heat treatment. The magnetic field is applied by a permanent magnet. The magnetic field intensity is 0.1T. It is only applied during the second stage of heat treatment. The first stage of heat treatment is 470°C heat treatment for 90 minutes, and the second stage heat treatment is 560°C heat treatment with heat preservation for 150 minutes.

The inductance of the magnetic core obtained in this embodiment at different frequencies can be tested using an impedance analyzer. Calculation shows that its relative magnetic permeability at 100 kHz is 31,800.

Example 4 This example provides a method for preparing a high-frequency, high-permeability iron-based nanocrystalline alloy, which includes the following steps:

Use metal elements Fe, Si, Cu and master alloys FeB, FeP, FeNb to weigh and batch the alloy components to obtain Fe ₇₅ Si _15.5 B ₆ P _0.5 Nb _1.5 Cu _1.5 for later use.

The obtained raw materials are smelted by vacuum induction. The melt is purified during the smelting process to reduce the harm caused by harmful impurity elements or inclusions. After smelting, a uniformly mixed alloy liquid is formed. After cooling, an alloy ingot is formed to prepare the alloy. The ingot is melted into molten alloy and used to make strips. During the strip making process, the casting temperature of the alloy liquid is controlled to be between 1390 and 1410°C. The alloy liquid is passed through a gravity single-roller strip machine to obtain a straight strip. The XRD method is used to detect whether the physical phase state of the strip is completely amorphous. status, collect the strips for later use.

The collected strips are cut to the required size and then rolled to make a circular magnetic core with an outer diameter of 30mm, an inner diameter of 20mm, and a height of 10mm. The inner and outer layers of the core are fixed by spot welding or other methods. , to prevent the core from spreading.

The magnetic core can obtain a nanocrystalline magnetic core with excellent performance after transverse magnetic field heat treatment. The treatment process is magnetic field heat treatment. The magnetic field is applied by coil. The magnetic field intensity is 0.01T, which is applied during the entire two-stage heat treatment process. The first stage of heat treatment is 480°C for 30 minutes, and the second stage of heat treatment is 580°C with heat preservation for 90 minutes.

The inductance of the magnetic core obtained in this embodiment at different frequencies can be tested using an impedance analyzer. Calculation shows that its relative magnetic permeability at 100 kHz is 29,300.

Example 5 This example provides a method for preparing a high-frequency, high-permeability iron-based nanocrystalline alloy, which includes the following steps:

Use metal elements Fe, Si, Cu and intermediate alloys FeB, FeP, FeNb to weigh and batch the alloy components to obtain Fe ₇₀ Si _15.5 B ₈ P ₄ Nb ₂ Cu _0.5 for later use.

The obtained raw materials are smelted by vacuum induction. The smelting is subjected to melt purification to reduce the harm caused by harmful impurity elements or inclusions. After smelting, a uniformly mixed alloy liquid is formed, and the alloy liquid can be directly used for belt making. During the strip making process, the casting temperature of the alloy liquid is controlled to be between 1330 and 1350°C. The alloy liquid is passed through a gravity single-roller belt spinning machine to obtain a straight strip. The XRD method is used to detect whether the physical phase state of the strip is completely amorphous. status, collect the strips for later use.

The collected strips are cut to the required size and then rolled to make a circular magnetic core with an outer diameter of 30mm, an inner diameter of 20mm, and a height of 10mm. The inner and outer layers of the core are fixed by spot welding or other methods. , to prevent the core from spreading.

After the magnetic core is subjected to transverse magnetic field heat treatment, a nanocrystalline magnetic core with excellent performance can be obtained. The treatment process is magnetic field heat treatment. The magnetic field is applied by a permanent magnet. The magnetic field intensity is 0.1T, which is applied during the entire two-stage heat treatment process. The first stage of heat treatment is 460°C heat treatment for 90 minutes, and the second stage heat treatment is 570°C heat treatment with heat preservation for 120 minutes.

The inductance of the magnetic core obtained in this embodiment at different frequencies can be tested using an impedance analyzer. Calculation shows that its relative magnetic permeability at 100 kHz is 31,500.

Example 6 This example provides a method for preparing a high-frequency, high-permeability iron-based nanocrystalline alloy, which includes the following steps:

Use metal elements Fe, Si, Cu and master alloys FeB, FeP, FeNb to weigh and batch the alloy components to obtain Fe _73.5 Si _16.5 B ₂ P ₅ Nb ₂ Cu ₁ for later use.

The obtained raw materials are smelted by non-vacuum induction method. The non-vacuum smelting method requires melt purification treatment to reduce the harm caused by harmful impurity elements or inclusions. After smelting, a uniformly mixed alloy liquid is formed. The alloy liquid is cooled to form Alloy ingots are prepared to be melted into alloy liquid and used for strip making. During the strip making process, the casting temperature of the alloy liquid is controlled between 1320 and 1340°C. The alloy liquid is passed through a pressure single-roller belt spinning machine to obtain a straight strip. The XRD method is used to detect whether the physical phase state of the strip is completely amorphous. status, collect the strips for later use.

The collected strips are cut to the required size and then rolled to make a circular magnetic core with an outer diameter of 30mm, an inner diameter of 20mm, and a height of 10mm. The inner and outer layers of the core are fixed by spot welding or other methods. , to prevent the core from spreading.

The magnetic core can obtain a nanocrystalline magnetic core with excellent performance after transverse magnetic field heat treatment. The treatment process is magnetic field heat treatment. The magnetic field is applied by an electromagnet. The magnetic field intensity is 1T, which is applied during the entire two-stage heat treatment process. The first stage of heat treatment is 470°C heat treatment for 120 minutes, and the second stage heat treatment is 560°C heat treatment with heat preservation for 150 minutes.

The inductance of the magnetic core obtained in this embodiment at different frequencies can be tested using an impedance analyzer. Calculation shows that its relative permeability at 100 kHz is 33600.

Comparative Example 1 This comparative example provides a method for preparing a high-frequency, high-permeability iron-based nanocrystalline alloy, which includes the following steps:

Use metal elements Fe, Si, Cu and intermediate alloys FeB and FeNb to weigh and batch the alloy components to obtain Fe _73.5 Si _20.5 B ₃ Nb ₂ Cu ₁ for later use.

The obtained raw materials are smelted by non-vacuum induction method. The non-vacuum smelting method requires melt purification treatment to reduce the harm caused by harmful impurity elements or inclusions. After smelting, a uniformly mixed alloy liquid is formed. The alloy liquid is cooled to form Alloy ingots are prepared to be melted into alloy liquid and used for strip making.

During the strip making process, the casting temperature of the alloy liquid is controlled between 1410 and 1430°C. The alloy liquid is passed through a gravity single-roller belt spinning machine to obtain a straight strip. The XRD method is used to detect whether the physical phase state of the strip is completely non-conforming. Crystallized state, collect the strips for later use. The test results indicate that the strips are in a crystallized state, and subsequent production will inevitably lead to complete deterioration of the magnetic properties.

Comparative Example 2 This comparative example provides a method for preparing a high-frequency, high-permeability iron-based nanocrystalline alloy, which includes the following steps:

Use metal elements Fe, Si, Cu and intermediate alloys FeB and FeNb to weigh and batch the alloy components to obtain Fe _73.5 Si _15.5 B ₇ Nb ₃ Cu ₁ for later use.

The obtained raw materials are smelted by non-vacuum induction method. The non-vacuum smelting method requires melt purification treatment to reduce the harm caused by harmful impurity elements or inclusions. After smelting, a uniformly mixed alloy liquid is formed. The alloy liquid is cooled to form Alloy ingots are prepared to be melted into alloy liquid and used for strip making. During the strip making process, the casting temperature of the alloy liquid is controlled to be between 1430 and 1450°C. The alloy liquid is passed through a gravity single-roller belt spinning machine to obtain a straight strip. The XRD method is used to detect whether the physical phase state of the strip is completely amorphous. status, collect the strips for later use.

The collected strips are cut to the required size and then rolled to make a circular magnetic core with an outer diameter of 30mm, an inner diameter of 20mm, and a height of 10mm. The inner and outer layers of the core are fixed by spot welding or other methods. , to prevent the core from spreading.

After the magnetic core is subjected to transverse magnetic field heat treatment, a nanocrystalline magnetic core with excellent performance can be obtained. The treatment process is magnetic field heat treatment. The magnetic field is applied by a permanent magnet. The magnetic field intensity is 0.1T, which is applied during the entire two-stage heat treatment process. The first stage of heat treatment is 470°C heat treatment for 120 minutes, and the second stage heat treatment is 560°C heat treatment with heat preservation for 150 minutes.

The inductance of the magnetic core obtained in this comparative example at different frequencies can be tested using an impedance analyzer. Calculation shows that its relative permeability at 100kHz is 26500.

Comparative Example 3 This comparative example provides a method for preparing a high-frequency, high-permeability iron-based nanocrystalline alloy, which includes the following steps:

Use metal elements Fe, Si, Cu and intermediate alloys FeB, FeP, FeNb to weigh and batch the alloy components to obtain Fe _73.5 Si ₁₄ B ₇ P _1.5 Nb ₃ Cu ₁ for later use.

The obtained raw materials are smelted by non-vacuum induction method. The non-vacuum smelting method requires melt purification treatment to reduce the harm caused by harmful impurity elements or inclusions. After smelting, a uniformly mixed alloy liquid is formed. The alloy liquid is cooled to form Alloy ingots are prepared to be melted into alloy liquid and used for strip making. During the strip making process, the casting temperature of the alloy liquid is controlled between 1400 and 1430°C. The alloy liquid is passed through a gravity single-roller strip machine to obtain a straight strip. The XRD method is used to detect whether the physical phase state of the strip is completely amorphous. status, collect the strips for later use.

The collected strips are cut to the required size and then rolled to make a circular magnetic core with an outer diameter of 30mm, an inner diameter of 20mm, and a height of 10mm. The inner and outer layers of the core are fixed by spot welding or other methods. , to prevent the core from spreading.

After the magnetic core is subjected to transverse magnetic field heat treatment, a nanocrystalline magnetic core with excellent performance can be obtained. The treatment process is magnetic field heat treatment. The magnetic field is applied by a permanent magnet. The magnetic field intensity is 0.1T, which is applied during the entire two-stage heat treatment process. The first stage of heat treatment is 470°C heat treatment for 120 minutes, and the second stage heat treatment is 560°C heat treatment with heat preservation for 150 minutes.

The inductance of the magnetic core obtained in this comparative example at different frequencies can be tested using an impedance analyzer. Calculation shows that its relative permeability at 100kHz is 26800.

Comparative Example 4 This comparative example provides a method for preparing a high-frequency, high-permeability iron-based nanocrystalline alloy, which includes the following steps:

Use metal elements Fe, Si, Cu and intermediate alloys FeB, FeP, FeNb to weigh and batch the alloy components to obtain Fe ₇₀ Si ₂₁ B ₃ P ₂ Nb ₃ Cu ₁ for later use.

The obtained raw materials are smelted by non-vacuum induction method. The non-vacuum smelting method requires melt purification treatment to reduce the harm caused by harmful impurity elements or inclusions. After smelting, a uniformly mixed alloy liquid is formed. The alloy liquid is cooled to form Alloy ingots are prepared to be melted into alloy liquid and used for strip making.

During the strip making process, the casting temperature of the alloy liquid is controlled to be between 1380 and 1400°C. The alloy liquid is passed through a gravity single-roller belt spinning machine to obtain a straight strip. The XRD method is used to detect whether the physical phase state of the strip is completely non-conforming. Crystallized state, collect the strips for later use. The test results indicate that the strips are in a crystallized state, and subsequent production will inevitably lead to complete deterioration of the magnetic properties.

Comparative Example 5 This comparative example provides a method for preparing a high-frequency, high-permeability iron-based nanocrystalline alloy, which includes the following steps:

Use metal elements Fe, Si, Cu and intermediate alloys FeB, FeP, FeNb to weigh and batch the alloy components to obtain Fe ₆₉ Si _20.5 B _0.5 P ₆ Nb ₃ Cu ₁ for later use.

The obtained raw materials are smelted by non-vacuum induction method. The non-vacuum smelting method requires melt purification treatment to reduce the harm caused by harmful impurity elements or inclusions. After smelting, a uniformly mixed alloy liquid is formed. The alloy liquid is cooled to form Alloy ingots are prepared to be melted into alloy liquid and used for strip making. During the strip making process, the casting temperature of the alloy liquid is controlled to be between 1310 and 1330°C. The alloy liquid is passed through a gravity single-roller belt spinning machine to obtain a straight strip. The XRD method is used to detect whether the physical phase state of the strip is completely amorphous. status, collect the strips for later use.

The collected strips are cut to the required size and then rolled to make a circular magnetic core with an outer diameter of 30mm, an inner diameter of 20mm, and a height of 10mm. The inner and outer layers of the core are fixed by spot welding or other methods. , to prevent the core from spreading.

After the magnetic core is subjected to transverse magnetic field heat treatment, a nanocrystalline magnetic core with excellent performance can be obtained. The treatment process is magnetic field heat treatment. The magnetic field is applied by a permanent magnet. The magnetic field intensity is 0.1T, which is applied during the entire two-stage heat treatment process. The first stage of heat treatment is 470°C heat treatment for 120 minutes, and the second stage heat treatment is 560°C heat treatment with heat preservation for 150 minutes.

The inductance of the magnetic core obtained in this comparative example at different frequencies can be tested using an impedance analyzer. Calculation shows that its relative permeability at 100kHz is 27200.

Although the present invention has been described with reference to illustrative embodiments, those skilled in the art will understand that various other changes, omissions and/or additions may be made and the substance thereof may be used without departing from the spirit and scope of the invention. Elements of the described embodiments may be replaced with effective ones. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from its scope. Therefore, it is intended that the invention not be limited to the particular embodiments disclosed for carrying out this invention, but that the invention will include all embodiments falling within the scope of the appended claims.

Claims (10)

1. A high-frequency and high-permeability iron-based nanocrystalline alloy, characterized in that: the chemical formula of the alloy is Fe _a Si _b B _c P _d Nb _e Cu _f M _g , where M is an impurity element, a, b , c, d, e, f and g are the atomic percentage contents of each element, a+b+c+d+e+f+g=100, and 15.5≤b≤20.5, g≤0.5. 2. The high-frequency high-permeability iron-based nanocrystalline alloy according to claim 1, characterized in that: 70≤a≤75, 3≤c≤8, 0.5≤d≤5, 1.5≤e≤3.5, 0.5 ≤f≤1.5. 3. The high-frequency high-permeability iron-based nanocrystalline alloy according to claim 1, characterized in that: the relative magnetic permeability of the iron-based nanocrystalline alloy at 100KHz is ≥ 29000. 4. The preparation method of the high-frequency high-permeability iron-based nanocrystalline alloy according to any one of claims 1-3, characterized in that it includes: preparing raw materials according to the composition of the iron-based nanocrystalline alloy, and proceeding in sequence. Smelting and heat treatment are performed to prepare the iron-based nanocrystalline alloy; wherein at least part of the heat treatment is performed in a magnetic field. 5. The preparation method according to claim 4, characterized in that: the intensity of the magnetic field is 0.01-1T. 6. The preparation method according to any one of claims 4-5, characterized in that: the source of the magnetic field includes a permanent magnet or an electromagnet. 7. The preparation method according to claim 1, characterized in that the heat treatment includes: first performing a first-stage heat treatment at 460-480°C for 30-120 minutes; and then performing a second-stage heat treatment at 540-580°C. , time is 90~180min. 8. The preparation method according to any one of claims 4 to 7, characterized in that: the entire process of the heat treatment is performed in the magnetic field. 9. The preparation method according to claim 7, characterized in that the second stage heat treatment is performed in the magnetic field. 10. The preparation method according to claim 4, characterized in that it specifically includes: smelting the raw material into an alloy liquid, processing it into a strip, and then performing the heat treatment on the strip to obtain the The iron-based nanocrystalline alloy.