Nanocrystalline alloy thin strip

Abstract

To provide a nanocrystalline alloy thin strip with low relative magnetic permeability. [Solution] The composition of the nanocrystalline alloy thin strip is represented by the following formula (1). Formula (1) Fe 100-a-b-c-d-e X a -Si b -B c -Cu d -M e (In formula (1) above, the units of a, b, c, d, and e are atomic percent. X is at least one element selected from Ni and Co. M is at least one element selected from Ti, V, Zr, Nb, Mo, Hf, Ta, and W. The values ​​of a, b, c, d, and e are as follows: 0.5 ≤ a ≤ 3.5, 14.0 ≤ b ≤ 17.0, 5.5 ≤ c ≤ 8.5, 0.0 ≤ d ≤ 1.5, 2.0 ≤ e ≤ 3.0). For example, the relative permeability at 10 kHz and 0.2 T is between 5000 and 13000.

Description

[Technical Field]

[0001] This disclosure relates to nanocrystalline alloy thin strips. [Background technology]

[0002] A noise filter is provided on the AC side of the in-vehicle inverter. A nanocrystalline alloy thin strip is used for the noise filter. The nanocrystalline alloy thin strip is disclosed in Patent Document 1. [Prior art documents] [Patent Documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 9-17623 [Overview of the project] [Problems that the invention aims to solve]

[0004] In recent years, motors have become more powerful and high-power. Power semiconductors have also become more high-frequency. To accommodate these increased motor power and high-power requirements, and the higher frequencies of power semiconductors, nanocrystalline alloy strips are required to have high saturation resistance. To improve saturation resistance, a low relative permeability is necessary. In one aspect of this disclosure, it is preferable to provide a nanocrystalline alloy strip with a low relative permeability. [Means for solving the problem]

[0005] One aspect of this disclosure is a nanocrystalline alloy thin strip whose composition is represented by the following formula (1). Equation (1) Fe 100-a-b-c-d-e X a -Si b -B c -Cu d -M e (In the formula (1), the units of a, b, c, d, and e are atomic %. X is at least one element selected from Ni and Co. M is at least one element selected from Ti, V, Zr, Nb, Mo, Hf, Ta, and W. The values of a, b, c, d, and e are as follows: 0.5 ≤ a ≤ 3.5, 14.0 ≤ b ≤ 17.0, 5.5 ≤ c ≤ 8.5, 0.0 ≤ d ≤ 1.5, 2.0 ≤ e ≤ 3.0) The nanocrystalline alloy ribbon, which is one aspect of the present disclosure, has a low relative permeability.

Mode for Carrying Out the Invention

[0006] Exemplary embodiments of the present disclosure will be described. <First Embodiment> 1. Structure of the nanocrystalline alloy ribbon The composition of the nanocrystalline alloy ribbon of the present disclosure is represented by the following formula (1). Formula (1) Fe 100-a-b-c-d-e X a -Si b -B c -Cu d -M e (In the formula (1), the units of a, b, c, d, and e are atomic %. X is at least one element selected from Ni and Co. M is at least one element selected from Ti, V, Zr, Nb, Mo, Hf, Ta, and W. The values of a, b, c, d, and e are as follows: 0.5 ≤ a ≤ 3.5, 14.0 ≤ b ≤ 17.0, 5.5 ≤ c ≤ 8.5, 0.0 ≤ d ≤ 1.5, 2.0 ≤ e ≤ 3.0)

[0007] Within the range of 0.5 or more and 3.5 or less, the larger the value of a, the lower the relative permeability of the nanocrystalline alloy ribbon. Within the range of 14.0 or more and 17.0 or less, the larger the value of b, the smaller the magnetostriction constant. Within the range of 5.5 or more and 8.5 or less, the larger the value of c, the higher the amorphous forming ability. When the value of d is 0.0 or more and 1.5 or less, the alloy ribbon is likely to have a fine nanocrystalline structure after heat treatment. When the value of e is 2.0 or more and 3.0 or less, the iron loss is low. For example, M contains Nb, and e is between 2.0 and 2.5. When e is 2.0 or greater, the precipitation of Fe-B, which causes grain coarsening and deterioration of magnetic properties, can be suppressed. When M contains Nb and e is less than 2.5, the mass concentration of Fe in the alloy can be increased, and the oxidation of part of the molten metal during casting, which clogs the nozzle, can be suppressed. Since Nb is easily oxidized, including Nb can suppress the oxidation of part of the molten metal.

[0008] The nanocrystalline alloy strip of this disclosure has a relative permeability of 5,000 to 15,000 when a magnetic field with a frequency of 10 kHz and a magnetic flux density of 0.2 T is applied, for example. The nanocrystalline alloy strip of this disclosure has a relative permeability of 5,000 to 1,500 when a magnetic field with a frequency of 100 kHz and a magnetic flux density of 0.2 T is applied, for example. When the relative permeability is within the above range, the relative permeability of the nanocrystalline alloy strip is a low value suitable for noise filtering.

[0009] For example, the nanocrystalline alloy thin strip of this disclosure exhibits an iron loss of 35 kW / m² when a magnetic field with a frequency of 10 kHz and a magnetic flux density of 0.2 T is applied. 3 The following applies: The nanocrystalline alloy thin strip of this disclosure exhibits an iron loss of 500 kW / m² when a magnetic field with a frequency of 100 kHz and a magnetic flux density of 0.2 T is applied. 3 The following applies: The nanocrystalline alloy strip of this disclosure has a magnetic flux density of 1.24 T or higher when a magnetic field of 800 A / m is applied.

[0010] The iron loss in a nanocrystalline alloy strip decreases as the saturation magnetostriction constant decreases. The magnetic flux density of a nanocrystalline alloy strip when a magnetic field of 800 A / m is applied increases as the mass concentration of Fe in the alloy increases.

[0011] The nanocrystalline alloy strips of this disclosure can be used, for example, in a common mode choke coil. A common mode choke coil is, for example, part of a noise filter. The nanocrystalline alloy strips of this disclosure can be used, for example, in a noise filter. A noise filter has the function of removing noise.

[0012] 2. Method for Manufacturing Nanocrystalline Alloy Ribbon As a method for manufacturing a nanocrystalline alloy ribbon, for example, the method described in JP-A-9-17623 can be cited. This manufacturing method is as follows. First, a molten alloy containing each component of the nanocrystalline alloy ribbon is rapidly cooled by the single-roll method to obtain an amorphous alloy ribbon. The thickness of the amorphous alloy ribbon is, for example, 3 to 100 μm, preferably 20 μm or less, more preferably 18 μm or less, and particularly preferably 16 μm or less.

[0013] Next, the amorphous alloy ribbon is slit into a ribbon having a predetermined width. Next, the amorphous alloy ribbon is heat-treated. When performing the heat treatment, the form of the amorphous alloy ribbon is, for example, a single plate or a toroidal core. The toroidal core is formed by winding the amorphous alloy ribbon. Through the above steps, a nanocrystalline alloy ribbon is obtained.

[0014] The composition of the manufactured nanocrystalline alloy ribbon is the same as that of the molten alloy. When performing the heat treatment, for example, the temperature is raised to the maximum temperature at a constant rate, then the temperature is maintained at the maximum temperature, and then the temperature is lowered at a constant rate. Hereinafter, unless otherwise specified, the heat treatment temperature means the maximum temperature. The heat treatment temperature is preferably 530°C or higher and 610°C or lower. The heat treatment temperature is higher than the crystallization temperature of the alloy. The atmosphere during the heat treatment is, for example, a nitrogen gas atmosphere.

[0015] 3. Effects Exhibited by Nanocrystalline Alloy Ribbon (1A) The nanocrystalline alloy ribbon of the present disclosure has a low relative permeability in the high-frequency region. Therefore, when the nanocrystalline alloy ribbon is used in a noise filter, even when the power of the motor is high or the frequency of the power semiconductor is high, the nanocrystalline alloy ribbon is difficult to saturate and difficult to generate heat. The high-frequency region is, for example, a region including 10 kHz or 100 kHz.

[0016] (1B) The nanocrystalline alloy ribbon of the present disclosure has low iron loss in the high-frequency region. Therefore, it is difficult to generate heat even when excited in the high-frequency region. The high-frequency region is, for example, a region including 10 kHz or 100 kHz. (1C) The nanocrystalline alloy ribbon of the present disclosure has a large magnetic flux density when a magnetic field of 800 A / m is applied. Therefore, it is excellent in terms of magnetic saturation resistance.

[0017] <Example> 1. Manufacture of Nanocrystalline Alloy Ribbons S1 to S12 The nanocrystalline alloy ribbons S1 to S12 were manufactured by the method described in the first embodiment. The composition of the alloy melt used for manufacturing the nanocrystalline alloy ribbons S1 to S12 was as shown in Table 1. The unit of the blending amount of each component in Table 1 is atomic %. The composition of the nanocrystalline alloy ribbons S1 to S12 was the same as the composition of the alloy melt used for their manufacture. The atmosphere during heat treatment was a nitrogen gas atmosphere. The thickness of the nanocrystalline alloy ribbons S1 to S12 was 18 μm.

[0018]

Table 1

[0019] For each of the nanocrystalline alloy ribbons S1 to S12, there were a plurality of types depending on the heat treatment temperature and the form of the amorphous alloy ribbon during heat treatment. The heat treatment temperature was at three levels of 550 °C, 570 °C, and 590 °C. As the form of the amorphous alloy ribbon during heat treatment, there were a single plate and a toroidal core.

[0020] 2. Evaluation of Nanocrystalline Alloy Ribbons S1 to S12 For each of the nanocrystalline alloy ribbons S1 to S12, the following characteristics were measured. Note that the magnetostriction constant λs was measured for some samples. Tx1 (°C), which is the crystallization temperature of the α-Fe phase Tx2 (°C), which is the crystallization temperature of the Fe-B compound Magnetostriction constant λs (ppm) Average crystal grain size (nm) B800T(T) Iron loss (kW / m²) when a magnetic field with a frequency of 10 kHz and a magnetic flux density of 0.2 T is applied. 3 ) Relative permeability μ' when a magnetic field with a frequency of 10 kHz is applied. Relative permeability μ'' when a magnetic field with a frequency of 10 kHz is applied. Q value when a magnetic field with a frequency of 10 kHz is applied. Iron loss (kW / m²) when a magnetic field with a frequency of 100 kHz and a magnetic flux density of 0.2 T is applied. 3 ) Relative permeability μ' when a magnetic field of 100 kHz is applied. Relative permeability μ'' when a magnetic field of 100 kHz is applied. Q value when a magnetic field with a frequency of 100 kHz is applied.

[0021] The method for measuring Tx1 involved using a Rigaku differential scanning calorimeter DSC8231 to measure the crystallization start temperature Tx1 of bccFe(αFe) at a heating rate of 10K / min. The method for measuring Tx2 involved using a Rigaku differential scanning calorimeter DSC8231 to measure the FeB precipitation initiation temperature Tx2 at a heating rate of 10 K / min. The method for measuring the magnetostrictive constant λs involved applying a magnetic field of 5 kOe to a sample (nanocrystalline alloy thin strip) to which a strain gauge manufactured by Kyowa Electric Industry was attached, rotating the electromagnet 360°, and measuring the maximum change in the elongation and contraction of the sample as a result of changing the direction of the magnetic field applied to the sample by 360°, based on the change in the electrical resistance value of the strain gauge. In this case, the magnetostrictive constant λs was defined as λs = 2 / 3 × maximum change. The method for measuring the average crystal grain size was to use the integral width of the diffraction peak from the (310) plane in the X-ray diffraction pattern of the nanocrystalline phase obtained from X-ray diffraction experiments, and to determine it using Scherrer's equation, which is shown in Equation 1 below. (Equation 1) D = (Kλ) / (Wcosθ) The integral width of the diffraction peak from the (310) plane is determined by peak decomposition using a pseudo-Voigt function for the diffraction pattern. If the average grain size is D, the integral width is W, the diffraction angle is θ, the Scherrer constant is K, and the X-ray wavelength is λ, then D can be determined from Scherrer's equation. In Scherrer's equation, the X-ray wavelength λ = 0.154050 nm and the Scherrer constant K = 1.333 were used. B800T represents the magnetic flux density when a magnetic field of 800 A / m is applied. The measurement method for B800T involved applying a magnetic field of 800 A / m to a heat-treated nanocrystalline alloy thin strip (toroidal core sample) using a DC magnetization characteristic tester manufactured by Metron Giken, and measuring the maximum magnetic flux density at that time.

[0022] The method for measuring iron loss involved placing a heat-treated nanocrystalline alloy thin strip (toroidal core sample, inner diameter 15 mm, outer diameter approximately 19 mm) in a case, with 3 turns of primary and secondary windings, and measuring the iron loss at frequencies of 10 kHz and magnetic flux densities of 0.2 T, and at 100 kHz and magnetic flux densities of 0.2 T. The method for measuring the relative permeability μ' involved placing a heat-treated nanocrystalline alloy thin strip (toroidal core sample, inner diameter 15 mm, outer diameter approximately 19 mm) in a case, winding the primary and secondary windings with one turn each, and measuring the relative permeability μ' at frequencies of 10 kHz and 100 kHz. The method for measuring the relative permeability μ'' was to place a heat-treated nanocrystalline alloy thin strip (toroidal core sample, inner diameter 15 mm, outer diameter approximately 19 mm) in a case, with one turn of primary and secondary windings, and measure the relative permeability μ'' at frequencies of 10 kHz and 100 kHz.

[0023] The measurement results for TX1 and TX2 are shown in Table 1. The measurement results for other properties are shown in Tables 2 to 4. Table 2 shows the measurement results for the nanocrystalline alloy strips S1 to S12 with a heat treatment temperature of 550°C. Table 3 shows the measurement results for the nanocrystalline alloy strips S1 to S12 with a heat treatment temperature of 570°C. Table 4 shows the measurement results for the nanocrystalline alloy strips S1 to S12 with a heat treatment temperature of 590°C.

[0024] [Table 2]

[0025] [Table 3]

[0026] [Table 4]

[0027] Regardless of the heat treatment temperature, the magnetostriction constant λs and average grain size were measured for nanocrystalline alloy strips S1 to S12, specifically those in the form of a single sheet of amorphous alloy strip during heat treatment. For other properties, the measurements were taken for nanocrystalline alloy strips S1 to S12, specifically those in the form of a toroidal core during heat treatment.

[0028] In Tables 2 to 4, (10kHz, 0.2T) indicates the measurement value when a magnetic field with a frequency of 10kHz and a magnetic flux density of 0.2T is applied. Similarly, (100kHz, 0.2T) indicates the measurement value when a magnetic field with a frequency of 100kHz and a magnetic flux density of 0.2T is applied.

[0029] As shown in Tables 2 to 4, nanocrystalline alloy strips S1 to S11 had lower relative permeability μ' and μ'' compared to nanocrystalline alloy strip S12. Nanocrystalline alloy strips S1 to S11 exhibited particularly low iron loss at 10 kHz and 100 kHz.

[0030] <Other Embodiments> Although embodiments of the present disclosure have been described above, the present disclosure is not limited to the embodiments described above and can be implemented in various modified forms.

[0031] (1) The function of one component in each of the above embodiments may be divided among multiple components, or the function of multiple components may be performed by one component. Also, some of the configurations of each of the above embodiments may be omitted. Also, at least some of the configurations of each of the above embodiments may be added to, replaced with, etc., the configurations of other embodiments.

[0032] (2) In addition to the nanocrystalline alloy thin strip described above, this disclosure can also be realized in various forms, such as a common mode choke coil containing the nanocrystalline alloy thin strip, a noise filter, a method for manufacturing the nanocrystalline alloy thin strip, a method for manufacturing the common mode choke coil, a method for manufacturing the noise filter, etc.

Claims

1. A nanocrystalline alloy thin strip whose composition is represented by the following formula (1). Formula (1) Fe １００－ａ－ｂ－ｃ－ｄ－ｅ X ａ -Si ｂ -B ｃ -Cu ｄ -M ｅ (In formula (1) above, the units of a, b, c, d, and e are atomic percent. X is at least one element selected from Ni and Co. M is at least one element selected from Ti, V, Zr, Nb, Mo, Hf, Ta, and W. The values ​​of a, b, c, d, and e are as follows: 0.5 ≤ a ≤ 3.5, 14.0 ≤ b ≤ 17.0, 5.5 ≤ c ≤ 8.5, 0.0 ≤ d ≤ 1.5, 2.0 ≤ e ≤ 3.0)

2. A nanocrystalline alloy thin strip according to claim 1, The relative permeability when a magnetic field with a frequency of 10 kHz is applied is between 5000 and 15000. Nanocrystalline alloy thin strip.

3. A nanocrystalline alloy thin strip according to claim 1 or 2, The relative permeability when a magnetic field with a frequency of 100 kHz is applied is between 5000 and 1500. Nanocrystalline alloy thin strip.

4. A nanocrystalline alloy thin strip according to claim 1, When a magnetic field with a frequency of 10 kHz and a magnetic flux density of 0.2 T is applied, the iron loss is 35 kW / m². ３ The following is: Nanocrystalline alloy thin strip.

5. A nanocrystalline alloy thin strip according to claim 1 or 4, When a magnetic field with a frequency of 100 kHz and a magnetic flux density of 0.2 T is applied, the iron loss is 500 kW / m. ３ The following is: Nanocrystalline alloy thin strip.

6. A nanocrystalline alloy thin strip according to claim 1, The magnetic flux density is 1.24 T or higher when a magnetic field of 8000 A / m is applied. Nanocrystalline alloy thin strip.

7. A nanocrystalline alloy thin strip according to claim 1, M contains Nb, e is between 2.0 and 2.

5. Nanocrystalline alloy thin strip

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