Nanocrystalline alloy with high-frequency and low-frequency magnetic conductivity, nanocrystalline magnetic ring and preparation method of nanocrystalline alloy and nanocrystalline magnetic ring

Abstract

The invention provides a nanocrystalline alloy with high-frequency and low-frequency magnetic conductivity, a nanocrystalline magnetic ring and a preparation method of the nanocrystalline alloy and the nanocrystalline magnetic ring, and belongs to the technical field of magnet material preparation. The chemical formula of the nanocrystalline alloy is Fe (100-x-y-z-a-b-c) Si < x > B < y > Nb < z > Cu Ni M < c >, wherein 8 < = x < = 13, 8 < = y < = 10, 0 < = z < = 1, 0 < = a < = 2, 0.5 < = b < = 5, and 0.5 < = c < = 3; m is Mo, Cr or Co. The preparation method comprises the following steps that the nanocrystalline alloy is made into a strip, and then the strip is wound into a magnetic core to be processed through an automatic strip winding machine; carrying out magnetic ring transverse magnetic heat treatment on the to-be-treated magnetic core by adopting a stepped distributed heat treatment process, wherein the stepped distributed heat treatment process comprises preheating treatment under a transverse magnetic condition and vacuum heat treatment of segmented heating and heat preservation; and after air blasting and rapid cooling, discharging to obtain the nanocrystalline magnetic ring with high-frequency and low-frequency high magnetic conductivity. The prepared magnetic ring has the effective magnetic conductivity of 45000 or above at the frequency of 100 kHz, meanwhile, the magnetic conductivity of 120 thousand or above can be reserved at the frequency of 1 KHz to 10 KHz, and the magnetic ring has the advantages of being low in loss, high in Bs value, high in magnetic conductivity and the like.

Description

Technical Field

[0001] The invention belongs to the technical field of magnetic material preparation, and particularly relates to a nanocrystalline alloy with both high-frequency and low-frequency high magnetic permeability, a nanocrystalline magnetic ring and a preparation method thereof. Background Art

[0002] Amorphous nanocrystalline soft magnetic alloys have high magnetic permeability, low coercivity, and excellent high-frequency soft magnetic properties. They are known as green electronic materials in the 21st century. In recent years, they have received extensive attention and research from academia and the business community. With the rapid development of computer network technology, 5G communications, electric vehicles, photovoltaic new energy, and multimedia technology, electronic devices have been required to be miniaturized, energy-efficient, and high-frequency, which has put forward newer and higher requirements for soft magnetic materials, that is, soft magnetic materials are required to have higher saturation magnetic induction intensity, higher magnetic permeability, lower loss, and good high-frequency performance. With the development of modern industry, it is hoped that soft magnetic materials will have higher magnetic permeability in a higher frequency range, such as 10KHz to 100KHz. The existing technology makes full use of the advantage that the transverse magnetic field annealing process can effectively reduce the residual magnetic induction intensity, and adopts vacuum transverse magnetic field annealing to improve the magnetic permeability of the iron-based nanocrystalline alloy core under high-frequency conditions: the effective magnetic permeability can reach about 150,000 at a frequency of 1KHz, the effective magnetic permeability can reach more than 120,000 at a frequency of 10KHz, and the effective magnetic permeability can reach up to 35,000 at a frequency of 100KHz.

[0003] Compared with traditional magnetic powder core materials, iron-based nanocrystalline alloy soft magnetic materials have the advantages of low loss and high Bs. There is a huge market space for energy storage inductors and common mode inductors in power devices such as new energy vehicles and server power supplies, especially in the field of new energy vehicles and charging piles. 73.5 Nb3Cu1Si 13.5 This magnetic ring has high magnetic permeability, but it is still unable to achieve a high frequency of 100KHz magnetic permeability of more than 40,000, and at the same time retain a low frequency end of 1KHz magnetic permeability of more than 100,000, which seriously affects the application field of the product. Summary of the invention

[0004] In view of this, the purpose of the present invention is to provide a nanocrystalline alloy, a nanocrystalline magnetic ring and a preparation method thereof having both high-frequency and low-frequency high magnetic permeability, aiming to solve at least one technical problem in the background technology.

[0005] The present invention is achieved in that:

[0006] The first aspect of the present invention provides a nanocrystalline alloy having both high-frequency and low-frequency high magnetic permeability, the chemical formula of the nanocrystalline alloy is: Fe (100-x-y-z-a-b-c) Si xB y Nb z Cu a Ni b M c； Among them, 8≤x≤13, 8≤y≤10, 0≤z<1, 0≤a≤2, 0.5≤b≤5, 0.5≤c≤3; M is Mo, Cr or Co.

[0007] The second aspect of the present invention provides a method for preparing the nanocrystalline magnetic ring having both high-frequency and low-frequency high magnetic permeability, the steps being as follows:

[0008] The nanocrystalline alloy is made into a strip, and then wound into a magnetic core to be processed by an automatic winding machine;

[0009] Adopting the step-by-step distributed heat treatment process to carry out the transverse magnetic heat treatment of the magnetic core to be treated;

[0010] After rapid cooling by blasting, the nanocrystalline magnetic ring with high magnetic permeability at both high and low frequencies is obtained.

[0011] The step-by-step distributed heat treatment process includes preheating treatment under transverse magnetic conditions and vacuum heat treatment with segmented heating and heat preservation.

[0012] Furthermore, the step-by-step distributed heat treatment process specifically includes:

[0013] Placing the magnetic core to be treated in a heat treatment furnace, applying a transverse magnetic field, heating the temperature to a first set temperature, and preheating the core at a constant temperature;

[0014] The preheated magnetic core is placed in a vacuum horizontal furnace, first heated to a first set temperature and kept warm; then heated to a second set temperature and kept warm; and finally heated to a third set temperature and kept warm.

[0015] Furthermore, the first set temperature is 410-430° C., and the preheating treatment is kept at this temperature for 25-35 minutes;

[0016] In a vacuum horizontal furnace, the magnetic core is kept at a first set temperature of 410-430°C for 25-35 minutes;

[0017] The second set temperature is set to 470-490°C and kept at this temperature for 55-65 minutes;

[0018] The third set temperature is set to 550-570° C. and kept at this temperature for 85-95 minutes;

[0019] The transverse magnetic field intensity in the step-distributed heat treatment process is set to 100-150 mT.

[0020] Furthermore, during the rapid air blast cooling process, a transverse magnetic field with an intensity of 100 to 150 mT is maintained.

[0021] Furthermore, the method for making the nanocrystalline alloy into a strip is as follows:

[0022] The raw materials of Fe-Si-B-Nb-Cu-Ni-M alloy are prepared according to the weight ratio converted from the chemical formula, the raw materials are added into a medium frequency induction furnace, and the temperature is raised to 1600-1680° C. for smelting;

[0023] After smelting, the slag is removed and molded to form a nanocrystalline alloy;

[0024] The nanocrystalline alloy is sprayed with a constant pressure stripping device to produce a strip with a thickness of 14 to 16 μm.

[0025] Furthermore, B is made of ferroboron master alloy, and the other raw materials are all single-element materials.

[0026] Furthermore, the filling factor of the magnetic core to be processed is set to 0.75-0.8.

[0027] The third aspect of the present invention provides a nanocrystalline magnetic ring having both high and low frequency high magnetic permeability obtained by the above method, wherein the magnetic permeability of the nanocrystalline magnetic ring is not less than 45,000 at a high frequency of 100kHz; and the magnetic permeability of the nanocrystalline alloy is not less than 120,000 at a low frequency below 10KHz.

[0028] Compared with the prior art, the present invention has the following beneficial effects:

[0029] 1. The present invention proposes an amorphous nanocrystalline alloy with high magnetic permeability through innovative amorphous alloy components and alloy preparation methods. After the amorphous alloy is heat treated, the formed nanocrystalline alloy has both high high-frequency and low-frequency high magnetic permeability, and has the characteristics of low loss, high Bs value, high magnetic permeability, etc.

[0030] 2. The present invention adds Ni element to the alloy to purify the alloy melt and increase the fluidity of the molten steel, so that the strip thickness and density can be better controlled during the strip spraying process, the filling factor of the magnetic ring can be improved, and the magnetic permeability of the magnetic ring can be increased.

[0031] 3. When preparing the magnetic ring, the present invention adopts transverse magnetic preheating followed by step-by-step segmented heating heat treatment to ensure that the magnetic domains generated in the initial stage of heat treatment are deflected in one direction and form copper clusters, so that the copper cluster characteristics are retained during subsequent heat treatment crystallization, thereby optimizing the magnetic permeability. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 This is a physical picture of the nanocrystalline magnetic ring prepared by the present invention;

[0033] Figure 2 1 is a hysteresis loop diagram of Example 1 of the present invention;

[0034] Figure 3 This is the magnetization loop diagram of Example 1 of the present invention. DETAILED DESCRIPTION

[0035] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the embodiments. It should be understood that the specific implementation cases described herein are only used to explain the present invention and are not used to limit the present invention.

[0036] Nanocrystalline alloy with high magnetic permeability at both high and low frequencies, its chemical formula is: Fe (100-x-y-z-a-b-c) Si x B y Nb z Cu a Ni b M c；

[0037] Among them, 8≤x≤13, 8≤y≤10, 0≤z<1, 0≤a≤2, 0.5≤b≤5, 0.5≤c≤3; M is Mo, Cr or Co.

[0038] The present invention adds Ni element, which can effectively reduce the residual magnetic induction intensity of the magnetic core and its magnetostriction coefficient as paramagnetic, reduce high-frequency loss and improve high-frequency magnetic permeability;

[0039] The present invention reduces the Nb element content, and changes the Nb element from the traditional 3% to less than 1%, which can better improve the fluidity of the molten steel of the strip. The reason is that: the Nb element has the highest melting point temperature, and reducing the proportion can achieve more uniform smelting and better fluidity of the molten steel, thereby increasing the toughness of the strip. The increased toughness of the strip allows the strip to be sprayed thinner during spraying. The thinner the strip is, the smaller the high-frequency loss is, and the higher the high-frequency magnetic permeability is.

[0040] A method for preparing a nanocrystalline magnetic ring having both high-frequency and low-frequency high magnetic permeability comprises the following steps:

[0041] S1, nanocrystalline alloy Fe (100-x-y-z-a-b-c) Si x B y Nb z Cu a Ni b M c The strip is made and then wound into a magnetic core to be processed by an automatic winding machine;

[0042] (1) Fe-Si-B-Nb-Cu-Ni-M alloy raw materials are prepared according to the weight ratio after conversion of the chemical formula, the raw materials are added into a medium frequency induction furnace, and the temperature is raised to 1600-1680° C. for smelting; wherein B is a boron iron master alloy, and the other raw materials are single-element materials;

[0043] (2) after smelting, slag removal and mold forming are performed to produce nanocrystalline alloy;

[0044] (3) The nanocrystalline alloy is sprayed with a constant pressure stripping device to form a strip with a thickness of 14 to 16 μm, and then a copper roller precision roller shearing machine is used to roll shear different width specifications;

[0045] (4) Use an automatic tape winding machine to wind the core. When winding the core, adjust the appropriate tension of the tape. The tape should not be pulled too tight when winding the core. The filling factor can be controlled within 0.75 to 0.8.

[0046] S2, using a step-by-step distributed heat treatment process to perform transverse magnetic heat treatment on the magnetic core to be treated;

[0047] (1) placing the magnetic core to be treated in a heat treatment furnace, applying a transverse magnetic field of 100 to 150 mT, and simultaneously heating to a first set temperature of 410 to 430° C., and preheating for 25 to 35 minutes;

[0048] During the heat treatment process, copper clusters will begin to form in the amorphous nanocrystalline ribbon. When the copper atoms begin to crystallize, a transverse magnetic field is applied to ensure that the magnetic domains generated at the beginning are deflected in one direction. In this step, heating can be performed in stages or directly from the initial temperature to the target temperature.

[0049] (2) The preheated magnetic core is placed in a vacuum horizontal furnace, first heated to a first set temperature of 410-430°C and kept warm for 25-35 minutes; then heated to a second set temperature of 470-490°C and kept warm for 55-65 minutes; then heated to a third set temperature of 550-570°C and kept warm for 85-95 minutes; the following embodiments of the present invention use a mechanical pump vacuum horizontal furnace, and the vacuum degree requirement is that the display scale is below -0.1MPa to meet the requirement;

[0050] The magnetic core is completely crystallized and annealed in a vacuum horizontal furnace to form a nanocrystalline structure of 10-20 nanometers. And because the magnetic domains are already in one direction and copper clusters have been formed, the above characteristics can be retained after annealing in the vacuum horizontal furnace, thereby obtaining better magnetic permeability.

[0051] S3, blast cooling quickly and then take out of the furnace;

[0052] After the heat treatment and insulation, the magnetic core is cooled quickly by blowing air with a blower. At the same time, a constant transverse magnetic field of 100-150mT is maintained during the cooling process to obtain a nanocrystalline magnetic ring with both high-frequency and low-frequency high magnetic permeability.

[0053] The nanocrystalline magnetic ring prepared by the above method has a magnetic permeability of not less than 45,000 at a high frequency of 100kHz; and a magnetic permeability of not less than 120,000 at a low frequency below 10KHz.

[0054] Example 1

[0055] A method for preparing a nanocrystalline magnetic ring having both high-frequency and low-frequency high magnetic permeability comprises the following steps:

[0056] S1. Configure Fe according to the weight ratio after chemical formula conversion 73.6 Si 10 B9 0.9 Cu1Ni3Mo 2.5 Alloy raw materials, add the raw materials into the medium frequency induction furnace, heat up to 1650℃ and melt for about 3 hours; B is made of ferroboron intermediate alloy, and the other raw materials are all single-element materials; after smelting, remove slag and cast into a nanocrystalline alloy; the nanocrystalline alloy is sprayed with a constant pressure stripping equipment to make a strip with a thickness of 14μm, and then a copper roller precision roller shear is used to roll cut different width specifications; an automatic winding machine is used to wind it into a magnetic core, and the appropriate strip tension is adjusted when winding the magnetic core. The strip should not be pulled too tight when winding the magnetic core, and the filling factor is set to 0.78.

[0057] S2. Place the magnetic core to be treated in a heat treatment furnace, apply a 100T transverse magnetic field, heat synchronously, raise the temperature to 420℃ within 30min, and keep it warm for 30min; place the preheated magnetic core in a vacuum horizontal furnace, first raise the temperature to 420℃ within 60min and keep it warm for 30min; then raise the temperature to 480℃ within 60min and keep it warm for 60min; raise the temperature to 560℃ within 60min and keep it warm for 90min.

[0058] S3, blast cooling quickly and then take out of the furnace;

[0059] After the heat treatment and insulation, the core is cooled quickly by blowing air with a blower. At the same time, a constant 100mT transverse magnetic field is maintained during the cooling process to obtain a nanocrystalline magnetic ring with both high-frequency and low-frequency high magnetic permeability. The size of the magnetic ring is OD*ID*HT=30*20*10mm. Figure 1 shown.

[0060] The measured inductance of the nanocrystalline magnetic ring obtained in this embodiment is AL = 90 μH @ 1 KHz; AL = 80 μH @ 10 KHz; AL = 30 μH @ 100 KHz; and according to the magnetic permeability μe = Ae * Le * 1000 / N 2 *0.4π*Ae, where Le is the magnetic path length of the magnetic ring, N is the filling factor, and Ae is the magnetic cross-sectional area of ​​the magnetic ring. It can be calculated that: μe=144000@1KHz; μe=128000@10KHz; μe=48000@100KHz.

[0061] The hysteresis loop and magnetization curve measuring instrument were used to measure the hysteresis loop and magnetization curve of the nanocrystalline magnetic ring prepared in Example 1. The results were referenced to Figure 2 and Figure 3 From the test data, we can see that the initial magnetic permeability of the product can reach 103K, the remanence Br is only 60mT, and the coercive force Hc=0.43A / m. The magnetic core made by this process has extremely low remanence and very small coercive force; and it also retains a magnetic permeability of more than 100,000.

[0062] Example 2

[0063] In this embodiment, a nanocrystalline magnetic ring having high magnetic permeability at both high and low frequencies is prepared. The thickness of the strip is 16 μm, and the remaining parameters, conditions, and steps are the same as those in Embodiment 1.

[0064] The measured inductance of the nanocrystalline magnetic ring obtained in this embodiment is AL = 95 μH @ 1 KHz; AL = 75 μH @ 10 KHz; AL = 28.5 μH @ 100 KHz; and according to the magnetic permeability μe = Ae*Le*1000 / N 2 *0.4π*Ae, where Le is the magnetic path length of the magnetic ring, N is the filling factor, and Ae is the magnetic cross-sectional area of ​​the magnetic ring. It can be calculated that: μe=152000@1KHz; μe=120000@10KHz; μe=45600@100KHz.

[0065] Example 3

[0066] In this embodiment, a nanocrystalline magnetic ring with high magnetic permeability at both high and low frequencies is prepared. The transverse magnetic field strength applied during the heat treatment process and cooling process is 150 mT, and the remaining parameters, conditions, and steps are the same as those in Example 1.

[0067] The measured inductance of the nanocrystalline magnetic ring obtained in this embodiment is AL=90μH@1KHz; AL=80μH@10KHz; AL=30μH@100KHz; and according to μe=Ae*Le*1000 / N 2 *0.4π*Ae, where Le is the magnetic path length of the magnetic ring, N is the filling factor, and Ae is the magnetic cross-sectional area of ​​the magnetic ring. It can be calculated that: μe=141000@1KHz; μe=131000@10KHz; μe=49700@100KHz.

[0068] Example 4

[0069] A method for preparing a nanocrystalline magnetic ring having both high-frequency and low-frequency high magnetic permeability comprises the following steps:

[0070] S1. Configure Fe according to the weight ratio after chemical formula conversion 72 Si 13 B10 Nb 0.5 Cu2Ni2Cr 0.5 Alloy raw materials, add the raw materials into the medium frequency induction furnace, heat up to 1600℃ and smelt for about 3 hours; among them, B uses boron iron intermediate alloy, and the other raw materials are all single-element materials; after the smelting, remove the slag and cast into a nanocrystalline alloy; the nanocrystalline alloy is sprayed with a constant pressure stripping equipment to make a strip with a thickness of 14μm, and then a copper roller precision roller shearing machine is used to roll cut different width specifications; an automatic winding machine is used to wind it into a magnetic core, and the appropriate strip tension is adjusted when winding the magnetic core. The strip should not be pulled too tight when winding the magnetic core, and the filling factor is set to 0.78.

[0071] S2. Place the magnetic core to be treated in a heat treatment furnace, apply a 100T transverse magnetic field, heat synchronously, raise the temperature to 410℃ within 30min, and keep it warm for 35min; place the preheated magnetic core in a vacuum horizontal furnace, first raise the temperature to 410℃ within 60min and keep it warm for 35min; then raise the temperature to 470℃ within 60min and keep it warm for 65min; raise the temperature to 550℃ within 60min and keep it warm for 95min.

[0072] S3. After the heat treatment and insulation, the magnetic core is cooled quickly by blowing air with a blower. At the same time, a constant 100mT transverse magnetic field is maintained during the cooling process to obtain a nanocrystalline magnetic ring with high magnetic permeability at both high and low frequencies. The size of the magnetic ring is OD*ID*HT=30*20*10mm.

[0073] The measured inductance of the nanocrystalline magnetic ring obtained in this embodiment is AL=83.2μH@1KHz; AL=74μH@10KHz; AL=28.8μH@100KHz; and according to the magnetic permeability μe=Ae*Le*1000 / N 2 *0.4π*Ae, where Le is the magnetic path length of the magnetic ring, N is the filling factor, and Ae is the magnetic cross-sectional area of ​​the magnetic ring. It can be calculated that: μe=130000@1KHz; μe=115000@10KHz; μe=45000@100KHz.

[0074] Example 5

[0075] A method for preparing a nanocrystalline magnetic ring having both high-frequency and low-frequency high magnetic permeability comprises the following steps:

[0076] S1. Configure Fe according to the weight ratio after chemical formula conversion 75.4 Si8B8Nb 0.1 Cu 0.5Ni5Co3 alloy raw materials are added into a medium frequency induction furnace and heated to 1670℃ for smelting for about 3 hours; B is made of ferroboron intermediate alloy, and the other raw materials are all single-element materials; after smelting, the slag is removed and the nanocrystalline alloy is formed by casting; the nanocrystalline alloy is sprayed with a constant pressure stripping equipment to form a strip with a thickness of 14μm, and the copper roller precision roller shearing machine is used to roll shear different width specifications; an automatic winding machine is used to wind the magnetic core, and the appropriate strip tension is adjusted when the magnetic core is wound. The strip should not be pulled too tight when winding the magnetic core, and the filling factor is set to 0.78.

[0077] S2. Place the magnetic core to be treated in a heat treatment furnace, apply a 100T transverse magnetic field, heat synchronously, raise the temperature to 430℃ within 30min, and keep it warm for 25min; place the preheated magnetic core in a vacuum horizontal furnace, first raise the temperature to 430℃ within 60min and keep it warm for 25min; then raise the temperature to 490℃ within 60min and keep it warm for 55min; raise the temperature to 570℃ within 60min and keep it warm for 85min.

[0078] S3. After the heat treatment and insulation, the magnetic core is cooled quickly by blowing air with a blower. At the same time, a constant 100mT transverse magnetic field is maintained during the cooling process to obtain a nanocrystalline magnetic ring with high magnetic permeability at both high and low frequencies. The size of the magnetic ring is OD*ID*HT=30*20*10mm.

[0079] The measured inductance of the nanocrystalline magnetic ring obtained in this embodiment is AL=71μH@1KHz; AL=61μH@10KHz; AL=30.1μH@100KHz; and according to the magnetic permeability μe=Ae*Le*1000 / N 2 *0.4π*Ae, where Le is the magnetic path length of the magnetic ring, N is the filling factor, and Ae is the magnetic cross-sectional area of ​​the magnetic ring. It can be calculated that: μe=110000@1KHz; μe=95000@10KHz; μe=48000@100KHz.

[0080] Example 6

[0081] A method for preparing a nanocrystalline magnetic ring having both high-frequency and low-frequency high magnetic permeability comprises the following steps:

[0082] S1. Configure Fe according to the weight ratio after chemical formula conversion 76.6 Si 12 B 9.5 Nb 0.7 Cu 0.2 Ni 0.5 Mo 0.5Alloy raw materials, add the raw materials into the medium frequency induction furnace, heat up to 1680℃ and smelt for about 3 hours; B is made of ferroboron intermediate alloy, and the other raw materials are all single-element materials; after smelting, remove slag and cast into a nanocrystalline alloy; the nanocrystalline alloy is sprayed with a constant pressure stripping equipment to form a strip with a thickness of 15μm; an automatic strip winding machine is used to wind it into a magnetic core, and the appropriate strip tension is adjusted when winding the magnetic core. The strip should not be pulled too tight when winding the magnetic core, and the filling factor is set to 0.8.

[0083] S2. Place the magnetic core to be treated in a heat treatment furnace, apply a 120T transverse magnetic field, heat synchronously, raise the temperature to 420℃ within 30min, and keep it warm for 30min; place the preheated magnetic core in a vacuum horizontal furnace, first raise the temperature to 420℃ within 60min and keep it warm for 30min; then raise the temperature to 480℃ within 60min and keep it warm for 60min; raise the temperature to 560℃ within 60min and keep it warm for 90min.

[0084] S3. After the heat treatment and insulation, the magnetic core is cooled quickly by blowing air with a blower. At the same time, a constant 120mT transverse magnetic field is maintained during the cooling process to obtain a nanocrystalline magnetic ring with high magnetic permeability at both high and low frequencies. The size of the magnetic ring is OD*ID*HT=30*20*10mm.

[0085] The measured inductance of the nanocrystalline magnetic ring obtained in this embodiment is AL=88μH@1KHz; AL=76μH@10KHz; AL=31μH@100KHz; and according to the magnetic permeability μe=Ae*Le*1000 / N 2 *0.4π*Ae, where Le is the magnetic path length of the magnetic ring, N is the filling factor, and Ae is the magnetic cross-sectional area of ​​the magnetic ring. It can be calculated that: μe=137000@1KHz; μe=118000@10KHz; μe=48500@100KHz.

[0086] Comparative Example 1

[0087] In this comparative example, nanocrystalline magnetic rings are prepared using conventional 1K107:Fe 73.5 Nb3Cu1Si 13.5 B9, the remaining parameters, conditions and steps are the same as those in Example 1.

[0088] The measured inductance of the nanocrystalline magnetic ring obtained in this comparative example is AL = 60μH@1KHz; AL = 45μH@10KHz; AL = 22μH@100KHz; and according to the magnetic permeability μe = Ae*Le*1000 / N 2*0.4π*Ae, where Le is the magnetic path length of the magnetic ring, N is the filling factor, and Ae is the magnetic cross-sectional area of ​​the magnetic ring. It can be calculated that: μe=96000@1KHz; μe=72000@10KHz; μe=35000@100KHz.

[0089] Comparative Example 2

[0090] In this comparative example, nanocrystalline magnetic rings are prepared using conventional 1K107:Fe 73.5 Nb3Cu1Si 13.5 B9, the remaining parameters, conditions and steps are the same as those in Example 2.

[0091] The measured inductance of the nanocrystalline magnetic ring obtained in this comparative example is AL=70μH@1KHz; AL=42μH@10KHz; AL=18μH@100KHz; and according to μe=Ae*Le*1000 / N 2 *0.4π*Ae, where Le is the magnetic path length of the magnetic ring, N is the filling factor, and Ae is the magnetic cross-sectional area of ​​the magnetic ring. It can be calculated that: μe=112000@1KHz; μe=67300@10KHz; μe=28800@100KHz.

[0092] It can be seen from Comparative Examples 1 and 2 that the magnetic ring made of conventional alloy has a magnetic permeability of less than 40,000 at a high frequency of 100KHz, a magnetic permeability of less than 75,000 at a low frequency of 10KHz, and a magnetic permeability of less than 115,000 at a low frequency of 1KHz.

[0093] Comparative Example 3

[0094] This comparative example prepares a nanocrystalline magnetic ring, and its heat treatment process steps are as follows:

[0095] (1) Horizontal furnace process: heat up to 420℃ for 60 minutes and keep it for 30 minutes, then heat up to 480℃ for 60 minutes and keep it for 60 minutes, then heat up to 560℃ for 60 minutes and keep it for 90 minutes, then take out the magnetic core;

[0096] (2) Horizontal magnetic furnace process: the magnetic core is placed in a heat treatment furnace, heated to 420°C for 60 minutes, and then kept at this temperature for 60 minutes, with a magnetic field intensity of 100 mT;

[0097] The remaining parameters, conditions and steps are the same as those in Example 1.

[0098] The measured inductance of the nanocrystalline magnetic ring obtained in this comparative example is AL = 75μH@1KHz; AL = 50μH@10KHz; AL = 23μH@100KHz; and according to the magnetic permeability μe = Ae*Le*1000 / N 2*0.4π*Ae, where Le is the magnetic path length of the magnetic ring, N is the filling factor, and Ae is the magnetic cross-sectional area of ​​the magnetic ring. It can be calculated that: μe=120000@1KHz; μe=80100@10KHz; μe=36800@100KHz.

[0099] It can be seen from Comparative Example 3 that although the specific alloy of the present invention is used but the conventional heat treatment process can achieve high magnetic permeability at low frequency, the magnetic permeability is reduced at high frequency, and it is impossible to achieve both.

[0100] The magnetic permeabilities of the nanocrystalline magnetic rings prepared in Examples 1 and 2 and Comparative Example 2 at different frequencies are summarized in Table 1 below.

[0101] Table 1

[0102]

[0103]

[0104] It can be seen from Table 1 that the nanocrystalline magnetic ring prepared by the present invention has a magnetic permeability of not less than 20,000 at a high frequency of 200kHz; a magnetic permeability of not less than 45,000 at a high frequency of 100kHz; and a magnetic permeability of not less than 120,000 at a low frequency below 10KHz; while the magnetic ring prepared by conventional alloys (Comparative Examples 1 and 2) or conventional heat treatment processes (Comparative Example 3) has a lower magnetic permeability than the present invention at both high and low frequencies.

[0105] The above-mentioned embodiments only express several implementation methods of the present invention, and the description thereof is relatively specific and detailed, but it cannot be understood as limiting the scope of the patent of the present invention. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, which all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. A nanocrystalline alloy having both high-frequency and low-frequency high magnetic permeability, characterized in that: The chemical formula of the nanocrystalline alloy is: Fe (100-x-y-z-a-b-c) Si x B y Nb z Cu a Ni b M c； Among them, 8≤x≤13,8≤y≤10,0≤z<1,0≤a≤2,0.5≤b≤5,0.5≤c≤3; M is Mo, Cr or Co.

2. A method for preparing a nanocrystalline magnetic ring having both high-frequency and low-frequency high magnetic permeability, characterized in that: The preparation method comprises the following steps: The nanocrystalline alloy according to claim 1 is made into a strip, and then wound into a magnetic core to be processed by an automatic winding machine; Adopting the step-by-step distributed heat treatment process to carry out the transverse magnetic heat treatment of the magnetic core to be treated; After rapid cooling by blasting, the nanocrystalline magnetic ring with high magnetic permeability at both high and low frequencies is obtained. The step-by-step distributed heat treatment process includes preheating treatment under transverse magnetic conditions and vacuum heat treatment with segmented heating and heat preservation.

3. The method for preparing a nanocrystalline magnetic ring having both high-frequency and low-frequency high magnetic permeability according to claim 2, characterized in that: The step-by-step distributed heat treatment process specifically includes: Placing the magnetic core to be treated in a heat treatment furnace, applying a transverse magnetic field, heating the temperature to a first set temperature, and preheating the core at a constant temperature; The preheated magnetic core is placed in a vacuum horizontal furnace, first heated to a first set temperature and kept warm; then heated to a second set temperature and kept warm; and finally heated to a third set temperature and kept warm.

4. The method for preparing a nanocrystalline magnetic ring having both high-frequency and low-frequency high magnetic permeability according to claim 3, characterized in that: The first set temperature is 410-430°C, and the preheating treatment is kept at this temperature for 25-35 minutes; In a vacuum horizontal furnace, the magnetic core is kept at a first set temperature of 410-430°C for 25-35 minutes; The second set temperature is set to 470-490°C and kept at this temperature for 55-65 minutes; The third set temperature is set to 550-570° C. and kept at this temperature for 85-95 minutes; The transverse magnetic field intensity in the step-distributed heat treatment process is set to 100-150 mT.

5. The method for preparing a nanocrystalline magnetic ring having both high-frequency and low-frequency high magnetic permeability according to claim 2, characterized in that: During the rapid blast cooling process, a transverse magnetic field with an intensity of 100 to 150 mT is maintained.

6. The method for preparing a nanocrystalline magnetic ring having both high-frequency and low-frequency high magnetic permeability according to claim 2, characterized in that: The method of making the nanocrystalline alloy according to claim 1 into a strip is as follows: The raw materials of Fe-Si-B-Nb-Cu-Ni-M alloy are prepared according to the weight ratio converted from the chemical formula, the raw materials are added into a medium frequency induction furnace, and the temperature is raised to 1600-1680° C. for smelting; After smelting, the slag is removed and molded to form a nanocrystalline alloy; The nanocrystalline alloy is sprayed with a constant pressure stripping device to produce a strip with a thickness of 14 to 16 μm.

7. The method for preparing a nanocrystalline magnetic ring having both high-frequency and low-frequency high magnetic permeability according to claim 6, characterized in that: B uses boron iron master alloy, and the other raw materials are all single-element materials.

8. The method for preparing a nanocrystalline magnetic ring having both high-frequency and low-frequency high magnetic permeability according to claim 2, characterized in that: The filling factor of the magnetic core to be processed is set to 0.75-0.

8.

9. A nanocrystalline magnetic ring having both high-frequency and low-frequency high magnetic permeability, characterized in that: The nanocrystalline magnetic ring is prepared by the preparation method described in any one of claims 2 to 8.

10. The nanocrystalline magnetic ring having both high-frequency and low-frequency high magnetic permeability according to claim 9, characterized in that: At a high frequency of 100kHz, the magnetic permeability of the nanocrystalline magnetic ring is not less than 45,000; at a low frequency below 10KHz, the magnetic permeability of the nanocrystalline alloy is not less than 120,000.

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