Low magnetic permeability amorphous alloy, preparation method and application thereof

Abstract

The application discloses a low magnetic permeability amorphous alloy, characterized in that the low magnetic permeability amorphous alloy is formed by segmental magnetic field heat treatment of an iron-based alloy disordered structure strip, and the alloy composition of the iron-based alloy disordered structure strip is Fe-Si-B-M, wherein M is one or more of C, Co, Nb, Mn, Cu and Ni. The application reduces the dislocation dipole density of the alloy, improves the structural disorder, effectively releases the internal stress, and combines the uniform magnetic anisotropy induced by the segmental magnetic field, so as to realize the low magnetic permeability and low loss of the amorphous alloy. The application further discloses a preparation method of the low magnetic permeability amorphous alloy and application of the low magnetic permeability amorphous alloy to a hybrid magnetic circuit distribution transformer.

Description

Technical Field

[0001] This invention belongs to the field of soft magnetic alloy materials technology, and particularly relates to a low magnetic permeability amorphous alloy, its preparation method and application. Background Technology

[0002] Compared to traditional soft magnetic materials, amorphous soft magnetic alloys are prepared using ultra-rapid solidification technology with a cooling rate of approximately one million degrees per second. Due to this ultra-rapid solidification, the atoms do not have enough time to arrange themselves in an orderly crystallization pattern during solidification, resulting in a long-range disordered structure in the solid alloy. The absence of grains and grain boundaries characteristic of crystalline alloys gives amorphous soft magnetic alloys superior properties such as high saturation magnetic induction and low coercivity. Furthermore, they exhibit "dual energy-saving" characteristics, saving energy during both manufacturing and use. Amorphous soft magnetic alloys can provide an effective solution for improving transformer conversion efficiency and reducing losses. Therefore, the development and application of amorphous soft magnetic materials are of great significance for the research and development of environmentally friendly, energy-efficient, and high-performance new power electronic devices such as transformers, instrument transformers, and sensors.

[0003] The superior soft magnetic properties of amorphous alloys bring significant energy-saving effects to transformers. The no-load loss of amorphous energy-saving transformers is about 70-80% lower than that of silicon steel. Allied Corporation (the predecessor of Metglas) developed the Fe-Si-B alloy in the 1960s, which was the first amorphous alloy to be industrialized. This alloy has a saturation magnetic flux density of 1.56T, significantly lower than the 1.64T saturation magnetic flux density of the Fe-Si-BC (HB1M) amorphous alloy launched by Hitachi Metals in 2006. Devices made using the new HB1M alloy developed by Hitachi Metals show reduced noise and losses, and the device size is reduced by 10%. However, at the magnetic saturation point, the permeability of ordinary amorphous alloys is about 5 times that of grain-oriented silicon steel. In hybrid magnetic circuit core transformer applications, the two materials cannot be matched when used together. There is an urgent need to develop amorphous alloys with low losses and low permeability to achieve the development and application of distribution transformers that combine the magnetic properties of amorphous and silicon steel.

[0004] CN201910772826.2 discloses a high-saturation magnetic induction iron-based amorphous alloy and its preparation method. The critical thickness of the amorphous alloy strip is ≥40μm; the saturation magnetic induction of the alloy strip sample is ≥1.65T; and the coercivity of the alloy strip sample is ≤5A / m. However, the amorphous alloy has a relatively high permeability.

[0005] CN201910061888.2 discloses a high-Bs amorphous material and its preparation method, wherein the typical composition of the amorphous ribbon is Fe. x Si y B zWhere x = 75-80%, y = 10-15%, and z = 7-10%, the amorphous ribbon is subjected to a first heat treatment and a second heat treatment under nitrogen protection. The first heat treatment specifically involves heating the amorphous ribbon from room temperature to 300-330°C at a heating rate of 5-20°C / min and holding it at that temperature for 20-40 minutes. The second heat treatment specifically involves heating the amorphous ribbon after the first heat treatment from 300-330°C to 380-430°C at a heating rate of 5-20°C / min and holding it at that temperature for 90-120 minutes. The amorphous ribbon after the second heat treatment is then cooled to obtain the high-Bs amorphous material. However, the coercivity of this amorphous alloy is as high as 42 A / m, which is not conducive to energy saving in transformers.

[0006] Therefore, there is an urgent need to develop an amorphous alloy that combines low loss, low magnetic permeability, good amorphous forming ability, and manufacturability. Summary of the Invention

[0007] The present invention provides a low permeability amorphous alloy, which has low permeability and low loss.

[0008] This invention provides a low magnetic permeability amorphous alloy, which is formed by segmented magnetic field heat treatment of iron-based alloy disordered structure strip. The alloy composition of the iron-based alloy disordered structure strip is Fe-Si-BM, where M is one or more of C, Co, Nb, Mn, Cu and Ni.

[0009] Furthermore, the alloy composition of the iron-based alloy disordered structure strip is Fe. a Si b B c C d Co e , 78≤a≤82, 4≤b≤9, 11≤c≤13, 0≤d≤1, 0≤e≤2, and a+b+c+d+e=100.

[0010] Furthermore, the alloy composition of the iron-based alloy amorphous ribbon is Fe. x Si 13 B8Nb2Mn2Cu1R y And 64≤x≤72, 2≤y≤10, R is Co or Ni.

[0011] Furthermore, the segmented magnetic field heat treatment process is as follows: the first segment magnetic field heat treatment temperature T1 is T c -50℃≤T1<T c T cThe temperature is the amorphous Curie temperature, and the holding time is t1. During time t1, a magnetic field F1 is applied perpendicular to the direction of the disordered iron-based alloy strip. The second stage of magnetic field heat treatment has a temperature T2 of T. c ≤T2≤T c +120℃, holding time is t2, magnetic field F2 is applied perpendicular to the direction of the disordered structure strip of iron-based alloy during time t2, and then rapidly cooled to the furnace exit temperature.

[0012] The Fe, Co, and Ni provided in this invention are ferromagnetic elements. The addition of Co and Ni increases the ferromagnetic coupling of the alloy, improving the magnetic moment and magnetocrystalline anisotropy. The addition of atoms C, Nb, Mn, and Cu increases the atomic mismatch ratio and mixing entropy of the alloy, increasing the disorder of the alloy system. Applying a magnetic field perpendicular to the disordered strip structure below the amorphous Curie temperature is beneficial because the amorphous phase is ferromagnetic at this temperature, and the magnetic moment direction is ordered. Combined with the ferromagnetic coupling effect of the ferromagnetic elements Fe, Co, and Ni, this induces uniform magnetic anisotropy perpendicular to the disordered strip structure, promoting stress relaxation and stress release. However, excessive uniform magnetic anisotropy, while reducing permeability, increases losses. When magnetic field heat treatment is performed above the amorphous Curie temperature, the amorphous phase of the iron-based alloy disordered structure strip becomes a paramagnetic phase, and the magnetic moment direction is disordered. Applying a magnetic field F2 perpendicular to the direction of the iron-based alloy disordered structure strip can induce a relatively weak uniform magnetic anisotropy, which synergistically achieves low loss and low permeability.

[0013] Furthermore, the amorphous Curie temperature T c The temperature ranges from 290℃ to 340℃.

[0014] Furthermore, the heat preservation time t1 is 10min-180min, and the magnetic field strength of magnetic field F1 is 80Oe-800Oe.

[0015] Applying a suitable magnetic field strength at time t1, combined with the ferromagnetic coupling effect of ferromagnetic elements Fe, Co, and Ni, induces a uniform magnetic anisotropy perpendicular to the disordered structure of the iron-based alloy strip, thereby enabling the amorphous alloy provided by this invention to have low magnetism and low loss. If the magnetic field strength is too high or the magnetic field is applied for too long, the uniform magnetic anisotropy will be too large, resulting in excessive loss.

[0016] Furthermore, the heat preservation time t2 is 10min-80min, and the magnetic field strength of magnetic field F2 is 160Oe-4500Oe.

[0017] Applying a suitable magnetic field strength perpendicular to the disordered structure strip within time t2 induces a relatively weak uniform magnetic anisotropy in the case that the amorphous phase of the iron-based alloy disordered structure strip is a paramagnetic phase, thereby enabling the amorphous alloy provided by the present invention to have lower magnetism and lower loss.

[0018] Furthermore, the rapid cooling rate is 100℃ / min–1500℃ / min. Rapid cooling restricts the transformation of the already formed amorphous structure with uniform magnetic anisotropy, thereby preserving the amorphous structure under the applied magnetic field F2.

[0019] Furthermore, the low-permeability amorphous alloy has a loss of less than 0.14 W / kg, preferably less than 0.1 W / kg, under conditions of 1.3T and 50Hz.

[0020] Furthermore, the low-permeability amorphous alloy maintains a constant permeability under conditions of 50Hz–100kHz, and is consistently less than 8000. More preferably, the low-permeability amorphous alloy has a permeability of 6000–7500 under conditions of 50Hz–100kHz.

[0021] Furthermore, the low-permeability amorphous alloy also includes unavoidable impurities.

[0022] The present invention also provides a method for preparing the aforementioned low-permeability amorphous alloy, comprising:

[0023] (1) The master alloy is obtained by batching and smelting according to the alloy composition of the iron-based alloy disordered structure strip, and the master alloy is obtained by single-roll rapid quenching.

[0024] (2) The disordered structure strip of iron-based alloy is heated to the first stage magnetic field heat treatment temperature T1 and held at that temperature for t1, where T... c -50℃≤T1<T c T c The temperature is the amorphous Curie temperature. A magnetic field F1 is applied perpendicular to the direction of the disordered strip structure during time t1, and then the temperature is raised to the second stage magnetic field heat treatment temperature T2 and held for t2, where T... c ≤T2≤T c At +120℃, a magnetic field F2 is applied perpendicular to the direction of the disordered structure strip of the iron-based alloy within time t2, and then rapidly cooled to the furnace exit temperature to obtain a low magnetic permeability amorphous alloy.

[0025] This invention also provides an application of the aforementioned low-permeability amorphous alloy in a hybrid magnetic circuit distribution transformer. When the low-permeability amorphous alloy provided by this invention is applied to a hybrid magnetic circuit distribution transformer, since the permeability of the low-permeability amorphous alloy is similar to that of silicon steel, it can improve the uniformity of the hybrid magnetic circuit structure, thereby reducing the overall performance loss of the hybrid magnetic circuit distribution transformer and improving its energy efficiency.

[0026] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0027] (1) This invention reduces the quasi-dislocation dipole density of the alloy by combining alloy composition, segmented magnetic field application, segmented heat preservation and rapid cooling, improves the structural disorder, effectively releases internal stress, and combines the uniform magnetic anisotropy induced by segmented magnetic field to achieve low permeability and low loss of amorphous alloy.

[0028] (2) The preparation method of this invention can reduce the loss and permeability of amorphous alloys. Under conditions of 1.3T and 50Hz, the loss is less than 0.14W / kg, and even less than 0.1W / kg. Under conditions of 50Hz, the permeability is less than 8000. Under conditions of 50Hz-100kHz, the permeability remains constant and is less than 8000. At the same time, it has good toughness. Therefore, the amorphous alloy prepared has excellent comprehensive performance, which can broaden the product market and application prospects of amorphous soft magnetic materials. Attached Figure Description

[0029] Figure 1 The images show the XRD patterns of the disordered structure strips obtained in Examples 1, 2, 3, and 4 of this invention.

[0030] Figure 2 This is a graph showing the change in magnetic permeability of the low-permeability amorphous alloy obtained in Example 1 of the present invention as a function of frequency. Detailed Implementation

[0031] The present invention will be further described in detail below with reference to the embodiments and accompanying drawings. It should be noted that the embodiments described below are intended to facilitate the understanding of the present invention and do not limit it in any way.

[0032] Example 1

[0033] (1) This embodiment is based on the chemical formula Fe 70 Si 13 After batching and alloy smelting of B8Nb2Mn2Cu1Co4, a master alloy was obtained. This master alloy was then used to produce a disordered iron-based alloy strip using a single-roll rapid quenching technique at a copper roll speed of 35 m / s. The microstructure of the strip produced by the rapid quenching technique was examined using a D8 Advance polycrystalline X-ray diffractometer (XRD). The results are as follows: Figure 1 As shown, Figure 1The data shows that the disordered structure of the iron-based alloy strip is amorphous.

[0034] (2) Place the iron-based alloy disordered structure strip in the furnace, heat it to 290℃ and hold it for 30 minutes. During the holding period, apply a magnetic field of 800 Oe perpendicular to the direction of the iron-based alloy disordered structure strip. Then heat it to 460℃ and hold it for 30 minutes. During the holding period, apply a magnetic field of 800 Oe perpendicular to the direction of the iron-based alloy disordered structure strip. Then cool it rapidly to 120℃ and take it out of the furnace.

[0035] Example 2

[0036] (1) This embodiment is based on the chemical formula Fe 72 Si 13 The master alloy was obtained by batching and smelting B8Nb2Mn2Cu1Ni2. This master alloy was then used to produce a disordered iron-based alloy strip using a single-roll rapid quenching technique at a copper roll speed of 35 m / s. The microstructure of the disordered iron-based alloy strip produced by the rapid quenching technique was examined using a D8 Advance polycrystalline X-ray diffractometer (XRD). The results are as follows: Figure 1 As shown, Figure 1 The data shows that the disordered structure of the iron-based alloy strip is amorphous.

[0037] (2) Place the iron-based alloy disordered structure strip in the furnace, heat it to 280℃ and hold it for 30 minutes. During the holding period, apply a magnetic field of 80 Oe perpendicular to the direction of the iron-based alloy disordered structure strip. Then heat it to 440℃ and hold it for 40 minutes. During the holding period, apply a magnetic field of 800 Oe perpendicular to the direction of the iron-based alloy disordered structure strip. Then cool it rapidly to 120℃ and take it out of the furnace.

[0038] Example 3

[0039] (1) This embodiment is based on the chemical formula Fe 81 Si4B 13 C1Co1 was used as raw material and smelted to obtain a master alloy. This master alloy was then subjected to single-roll rapid quenching technology to produce iron-based alloy strips with a disordered structure. The copper roller rotation speed was 35 m / s. The microstructure of the strips produced by the rapid quenching technology was examined using a D8 Advance polycrystalline X-ray diffractometer (XRD). The results are as follows: Figure 1 As shown, Figure 1 The data shows that the disordered structure of the iron-based alloy strip is amorphous.

[0040] (2) Place the iron-based alloy disordered structure strip in the furnace, heat it to 270℃ and hold it for 30 minutes. During the holding period, apply a magnetic field of 100 Oe perpendicular to the direction of the disordered structure strip. Then heat it to 390℃ and hold it for 30 minutes. During the holding period, apply a magnetic field of 1000 Oe perpendicular to the direction of the strip. Then cool it rapidly to 120℃ and take it out of the furnace.

[0041] Example 4

[0042] (1) This embodiment is based on the chemical formula Fe 82 Si4B 13 C1 was used for batching and smelting to obtain a master alloy. This master alloy was then subjected to single-roll rapid quenching technology to produce a disordered iron-based alloy strip. The copper roller rotation speed was 35 m / s. The microstructure of the strip produced by the rapid quenching technology was examined using a D8 Advance polycrystalline X-ray diffractometer (XRD). The results are as follows: Figure 1 As shown, Figure 1 The data shows that the disordered structure of the iron-based alloy strip is amorphous.

[0043] (2) Place the iron-based alloy disordered structure strip in the furnace, heat it to 260℃ and hold it for 30 minutes. During the holding period, apply a magnetic field of 80 Oe perpendicular to the direction of the disordered structure strip. Then heat it to 380℃ and hold it for 30 minutes. During the holding period, apply a magnetic field of 800 Oe perpendicular to the direction of the strip. Then cool it rapidly to 120℃ and take it out of the furnace.

[0044] Example 5

[0045] Unlike Example 4, in step (2), the iron-based alloy disordered structure strip is placed in a furnace, heated to 260°C and held for 120 minutes. During the holding period, a magnetic field of 80 Oe is applied in the direction perpendicular to the disordered structure strip. Then, the temperature is raised to 380°C and held for 30 minutes. During the holding period, a magnetic field of 800 Oe is applied in the direction perpendicular to the strip. Then, it is rapidly cooled to 120°C and removed from the furnace.

[0046] Comparative Example 1

[0047] The difference from Example 1 is that no magnetic field was applied during the heat preservation period. The amorphous alloy samples prepared in Example 1 and Comparative Example 1 were tested as follows:

[0048] Loss tests were conducted using an AC BH meter, which showed that the loss of the sample after heat treatment in Example 1 was 1.18 W / kg at 1.3T and 50Hz, which is much lower than the loss of 2 W / kg of the alloy sample after heat treatment in Comparative Example 1.

[0049] Loss was tested using an impedance analyzer, and the test results are as follows: Figure 2 As shown, the magnetic permeability of the sample after heat treatment in Example 1 is relatively stable.

[0050] Application examples

[0051] The core of a hybrid magnetic circuit distribution transformer is prepared by combining and stacking low-permeability amorphous alloy strips obtained in Example 1 with silicon steel sheets, and then the hybrid magnetic circuit distribution transformer is obtained by winding the core with copper wire.

[0052] Performance Analysis:

[0053] As can be seen from Table 1, the permeability of the amorphous alloys prepared in Examples 1-5 at 100 kHz is 6700-7350, which is relatively low and stable. The permeability of the amorphous alloy prepared in Comparative Example 1 is 143000 at 50 Hz and 6500 at 100 kHz, which is less stable. At 1.3T and 50 Hz, the loss of the amorphous alloys prepared in Examples 1-5 is 1.18-1.35, which is lower than the loss of the amorphous alloy prepared in Comparative Example 1. Therefore, the amorphous alloys prepared in Examples 1-5 have low permeability and low magnetic loss.

[0054] Table 1. Performance test results of Examples 1-5 and Comparative Example 1

[0055]

[0056] The embodiments described above provide a detailed explanation of the technical solution of the present invention. It should be understood that the above descriptions are merely specific embodiments of the present invention and are not intended to limit the present invention. Any modifications, additions, or similar substitutions made within the scope of the principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A low-permeability amorphous alloy, characterized in that, The low permeability amorphous alloy is formed by segmented magnetic field heat treatment of iron-based alloy disordered structure strip. The alloy composition of the iron-based alloy disordered structure strip is Fe-Si-BM, where M is one or more of C, Co, Nb, Mn, Cu and Ni. The segmented magnetic field heat treatment process is as follows: the temperature T1 of the first segment of magnetic field heat treatment is T... c -50℃≤T1<T c T c The amorphous Curie temperature T is the Curie temperature of the amorphous material. c The temperature is 290℃-340℃, and the holding time is t1. During time t1, a magnetic field F1 is applied perpendicular to the direction of the disordered iron-based alloy strip. The magnetic field strength of F1 is 80 Oe-800 Oe. The second stage of magnetic field heat treatment temperature T2 is T... c ≤T2≤T c +120℃, holding time is t2, during which a magnetic field F2 is applied perpendicular to the direction of the disordered structure strip of iron-based alloy. The magnetic field strength of the magnetic field F2 is 160 Oe-4500 Oe. Then, it is rapidly cooled to the furnace exit temperature at a rate of 100 ℃ / min-1500 ℃ / min.

2. The low-permeability amorphous alloy according to claim 1, characterized in that, The alloy composition of the iron-based alloy disordered structure strip is Fe. a Si b B c C d Co e 78≤a≤82, 4≤b≤9, 11≤c≤13, 0≤d≤1, 0≤e≤2, and a+b+c+d+e =100, where d and e are not both 0.

3. The low-permeability amorphous alloy according to claim 1, characterized in that, The alloy composition of the iron-based alloy disordered structure strip is Fe. x Si 13 B8Nb2Mn2Cu1R y And 64≤ x ≤72, 2≤y≤10, R is Co or Ni.

4. The low-permeability amorphous alloy according to claim 1, characterized in that, The heat preservation time t1 is 10 min to 180 min.

5. The low-permeability amorphous alloy according to claim 1, characterized in that, The heat preservation time t2 is 10 min to 80 min.

6. The low-permeability amorphous alloy according to claim 1, characterized in that, The low-permeability amorphous alloy has a loss of less than 0.14 W / kg under 1.3 T and 50 Hz conditions; the permeability remains constant under 50 Hz-100 kHz conditions, and is less than 8000 in all cases.

7. The low-permeability amorphous alloy according to claim 1, characterized in that, The low-permeability amorphous alloy has a loss of less than 0.1 W / kg under conditions of 1.3 T and 50 Hz.

8. The low-permeability amorphous alloy according to claim 1, characterized in that, The low-permeability amorphous alloy has a permeability of 6000-7500 under conditions of 50Hz-100kHz.

9. A method for preparing a low-permeability amorphous alloy according to any one of claims 1-8, characterized in that, include: (1) The master alloy is obtained by batching and smelting the alloy composition of the iron-based alloy disordered structure strip according to any one of claims 1-8, and the master alloy is obtained by single-roll rapid quenching. (2) The iron-based alloy disordered structure strip is heated to the first stage magnetic field heat treatment temperature T1 and held at that temperature for t1, where T c -50℃≤T1<T c T c The temperature is the amorphous Curie temperature. A magnetic field F1 is applied perpendicular to the direction of the disordered strip structure during time t1, and then the temperature is raised to the second stage magnetic field heat treatment temperature T2 and held for t2, where T... c ≤T2≤T c At +120℃, a magnetic field F2 is applied perpendicular to the direction of the disordered structure strip of the iron-based alloy within time t2, and then rapidly cooled to the furnace exit temperature to obtain a low magnetic permeability amorphous alloy.

10. The application of a low-permeability amorphous alloy according to any one of claims 1-8 in a hybrid magnetic circuit distribution transformer.

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