JPH06220592A - Amorphous alloy with low iron loss and high magnetic flux density - Google Patents

Abstract

(57) [Summary] [Object] To provide an amorphous alloy for a power transformer iron core, which has a high saturation magnetic flux density Bs and is free from deterioration of iron loss accompanying the improvement of Bs. [Structure] FeCoSiBM (M is at least 1 of Sn, Cu, S)
Amorphous magnetic alloy produced by the single-sided quenching method with the composition indicated by (Seed). However, Fe: 60 to 83, Co: 3 to 20, and 80 ≦
Fe + Co ≦ 86, 1 ≦ Si ≦ 10, 11 ≦ B ≦ 16, M is Sn ≦ 0.1 ≦ Sn ≦ 1, Cu is 0.1 ≦ Cu ≦ 2.0, and S is 0.01 ≦ S ≦ 0.07. The properties of this alloy after annealing in a magnetic field are Bs ≧ 1.7T, magnetic flux density at 1Oe is 1.55T or more, and iron loss at 50Hz, 1.6T is 0.30W / kg or less. Is characterized by. [Effect] High Bs and low loss contribute to miniaturization and high efficiency as an iron core for power transformers and aircraft transformers.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an amorphous magnetic alloy suitable for applications such as power transformers, aircraft transformers, magnetic switches, and iron cores of smooth chokes that require high saturation magnetic flux density and low loss. is there.

[0002]

2. Description of the Related Art Fe-based amorphous alloys produced by liquid quenching have been regarded as promising as iron core materials for power transformers and high-frequency transformers because of their extremely small iron loss. However, it has not yet been fully commercialized. One of the factors is that the saturation magnetic flux density is considerably lower than that of silicon steel sheets, and therefore the iron core cross-sectional area must be increased to obtain a predetermined magnetic flux. Increasing the size of the iron core increases the weight and volume of the transformer, which is a secondary factor in increasing the cost of the transformer. Therefore, a design concept is created in which the transformer cost is minimized by increasing the saturation magnetic flux density while slightly sacrificing the cost of the iron core material.

Saturation magnetic flux density (Bs) of Fe-based amorphous alloy
In order to increase the temperature, the technical idea of substituting a part of Fe with Co is that Hatta et al.
i et al. have proposed the Fe-Si-B system. However, the former had a low thermal stability, and the latter had a practical value of Bs of about 1.65 T despite the substitution of Co.

After that, the same Fe-- as in Fujimori et al.
By limiting the composition range of each element in the Co-Si-B system, it is possible to obtain an amorphous alloy having a high Bs.
It was proposed by the publication 6-139653. When the specific composition is expressed in atomic%, Fe: 64.0 to 80.0%,
Co: 7.0 to 20.0%, B: 13.0 to 15.0
%, Si: more than 0 to 1.5%. An amorphous alloy satisfying this composition condition has a magnetic flux density of 1.69 to 1.73 T in a magnetic field of 80 A / m, a small DC coercive force, and a magnetic field density of 1.6 T under an alternating magnetic field of 400 Hz. It is shown in the examples that the iron loss and the excitation VA are small. The crystallization temperature of the typical example of this amorphous alloy is about 430 ° C.
It is emphasized that it has characteristics suitable for transformer cores for aircraft.

The amorphous alloy disclosed in Japanese Unexamined Patent Publication (Kokai) No. 56-139553 is an Fe-Si alloy currently on the market.
Although Bs is up to about 15% higher than that of the -B type amorphous alloy, iron loss is increased, but it has not been possible to apply it to the iron core of a power transformer. Also, the thermal stability was inferior to that of the Fe-Si-B based amorphous alloy.

[0006]

SUMMARY OF THE INVENTION It is an object of the present invention to provide an amorphous alloy for a power transformer iron core, which is free from deterioration of iron loss due to improvement of saturation magnetic flux density.

[0007]

The gist of the present invention resides in that (1) the composition is Fe _a Co _b Si _c B _d M _x, which is produced by a single-sided cooling method and has a low temperature. loss·
High magnetic flux density amorphous alloy. However, M is at least one of Sn, Cu and S, and a, b, c, d and x are atomic%
, 60 ≦ a ≦ 83, 3 ≦ b ≦ 15, and 80 ≦ a + b
≦ 86, 1 ≦ c ≦ 10, 11 ≦ d ≦ 16, x is 0.1 ≦ x ≦ 1.0 for Sn, and 0.1 ≦ x ≦ 2 for Cu.
In the case of 0 and S, 0.01 ≦ x ≦ 0.07 and a + b
+ C + d + x = 100. (2) A low iron loss / high magnetic flux density amorphous alloy as set forth in (1) above, wherein a part of Si and B is replaced with C in a total maximum of 4 atom%. Saturation magnetic flux density is 1.7 Tesla (T) as a characteristic of the ribbon after annealing in a magnetic field measured at room temperature.
The magnetic flux density is 1.55 tesla or more when a magnetic field of 1 oersted (Oe) (1 Oe = 80 A / m) is applied, and the iron loss at 50 Hz and 1.6 tesla is 0.30 W / kg or less. A low iron loss and high magnetic flux density amorphous alloy as described in the above items. Further, (4) the plate thickness is 40 to 100 μ.
m is the low iron loss / high magnetic flux density amorphous alloy as described in the preceding items. Incidentally, the above-mentioned amorphous alloy has improved mechanical properties after annealing.

That is, according to the present invention, by adding a trace amount of Sn, Cu, or S to an amorphous alloy in which a part of Fe is replaced by Co, the iron loss at high operating magnetic flux density is low and the thermal stability is high. This is an amorphous alloy ribbon with high properties. It was also found that the addition of Sn, Cu, and S also improves the ability to form an amorphous substance, and simultaneously imparts a thick plate thickness and improved mechanical properties after annealing.

FIGS. 1A, 1B and 1C are respectively 25 mm wide and 30 μ thick prepared by the single roll quenching method.
m Fe-Co-Si-B-X (X = Sn, Cu, S)
The effect of the addition amount on the iron loss of the additional element X in the amorphous alloy ribbon is shown. As shown in FIG. 1, S of the present invention
The Fe-Co-Si-B alloy added with n, Cu and S is
The iron loss is remarkably improved as compared with the conventional case of no addition. S
It is considered that n, Cu, and S have the effect of suppressing crystallization of the ribbon surface layer, and this is considered to contribute to the improvement of magnetic properties after annealing.

The reason why the addition of Sn, Cu, and S exhibits the above effect is not clear at this time. The results of surface analysis by glow discharge emission spectroscopy (GDS) conducted by the present inventors show that Fe, Co, and Si containing Sn, Cu, and S are added.
-B Amorphous concentration segregation of these additive elements is observed on the surface of the amorphous ribbon, especially on the free surface (the surface opposite to the surface in contact with the roll), and the main components such as Fe, Si, B and Co are also present. The distribution is changing. From this, Sn, C
It is presumed that u and S protect the unstable amorphous ribbon surface layer by protecting it from crystallization and stabilizing it. Usually, as a result of suppressing the crystallization of the surface layer which is the starting point of crystallization, it is considered that the stress generation is small and the iron loss is improved. Further, in the case of Cu, it acts to lower the crystallization temperature of the bulk (inside the ribbon). It is considered that when there is no time difference between the start of crystallization on the surface and the inside, the crystallization progresses uniformly and the occurrence of strain is reduced, and as a result, the deterioration of magnetic properties is suppressed. The present invention relates to the Sn,
Based on the surface crystallization suppressing effect of Cu and S, it has a high Bs
Applied to the stabilization of the Fe-Co-Si-B amorphous alloy of
It has been completed.

Next, the reason for limiting the composition in the present invention will be described. Fe and Co contents a and b are amorphous ribbons B
s was set to be 1.70 T or higher after annealing. The conditions are 60 ≦ a ≦ 83, 3 ≦ b ≦ 20, and 80 ≦ a + b ≦ 86. If either a or b falls below the lower limit value, Bs will be less than 1.7 T, so the respective lower limits were set. Further, the upper limit was set in consideration of the amorphous forming ability and the economical efficiency. That is, if the sum of Fe and Co exceeds 86%, amorphization becomes difficult, so the upper limit of a + b is 86.
And the addition of Co is at least 3 (atomic%) in order to make Bs 1.7 T or more, and the upper limit is 2 from the viewpoint of economic efficiency.
I kept it at 0. Even if Co is in the above range, Bs ≧ 1.7T cannot be achieved if Fe is insufficient. For the above reasons, the lower limit of a + b is set to 80, and the lower limit of Fe is set to 60.

The addition amounts of Sn, Cu and S are specified mainly from the viewpoint of suppressing the surface crystallization. The respective lower limit values are the minimum values required to exert the suppressing effect on the surface crystallization, and are 0.1 (atomic%) for both Sn and Cu and 0.01 for S. is there. The upper limit of each was limited mainly considering the mechanical properties of the ribbon. If the addition amount exceeds the upper limit value, the ribbon may become brittle, and in order to avoid this, it is limited to 1.0 (atomic%) for Sn, 2.0 for Cu, and 0.07 or less for S. did.

Si and B are indispensable elements for forming an amorphous material, and 1≤Si≤10 and 1 respectively.
It is necessary to satisfy 1 ≦ B ≦ 16. However, a part of Si and B can be replaced with C within a range not exceeding 4 atom% in total. If either Si or B is less than this lower limit, an amorphous phase is less likely to be formed, and if it exceeds the upper limit, the desired magnetic characteristics, particularly the saturation magnetic flux density, cannot be achieved, which is not preferable.

Next, embodiments of the present invention will be described. First, the main components of Fe, Co, Si and B and the additional elements Sn and C
A raw material or a mother alloy in which at least one of u and S is mixed so as to have the above-described predetermined composition range is melted. However, in addition to the above-mentioned elements, the following elements may be contained in a range that does not impair the high saturation magnetic flux density and the low loss property which are the objects of the present invention. Specifically, V, Mn, Mo, Nb, Ta,
It is 2 (atomic%) or less of W, Cr, Hf, and Ni. It is known that these elements are effective in improving magnetic permeability, corrosion resistance, and thermal stability.

The melt of the melted alloy is formed into an amorphous ribbon by using a single-sided cooling method such as a normal single roll quenching method.
The nozzle used at this time may be a single slit nozzle or a multiple slit nozzle. Here, the single slit nozzle is a nozzle having an elongated slit-shaped opening having a width of 0.2 to 1.0 mm measured in the moving direction of the cooling substrate, and is suitable for manufacturing a thin ribbon having a plate thickness of 40 μm or less. There is. The multiple slit nozzle method is disclosed in Japanese Examined Patent Publication No. 63-406.
The method disclosed in Japanese Patent No. 29, which uses a nozzle in which a plurality of slit-shaped openings are arranged at a predetermined interval (usually 1 mm to 4 mm) in the moving direction of the substrate, and is suitable for manufacturing thick materials of 45 μm or more. ing. The casting atmosphere may be air, inert gas, or vacuum.

The characteristics of the amorphous alloy ribbon produced as described above after annealing in a magnetic field have Bs of at least 1.7 T.
The magnetic flux density is 1.55 tesla or more when a magnetic field of 1 Oersted (Oe) is applied, and 50 Hz, 1.
Iron loss at 6 Tesla is less than 0.30 W / kg. The annealing conditions are set such that the maximum temperature is in the range of 260 ° C. to 360 ° C., and this temperature is maintained for 1 minute or more and less than 120 minutes.

[0017]

EXAMPLES Hereinafter, examples will be described. (Example 1) After producing a master alloy having each composition shown in Table 1, this master alloy was subjected to high frequency melting. The melted mother alloy is passed through a nozzle having a slit-shaped opening, and the peripheral speed is 24 seconds per second.
It was rapidly cooled on the outer peripheral surface of the Cu roll rotating at m to form a ribbon. The nozzle used here is a single slit (width 0.6 mm, length 25 mm). Thickness of the obtained ribbon,
The amorphous properties analyzed by X-ray diffraction are shown in Table 1.

Samples taken from three different points of the amorphous ribbon were measured for iron loss and magnetic permeability with a single plate tester. The dimensions of the sample are 120 mm long and 25 mm wide. Before each magnetic measurement, a magnetic field of 10 Oe was applied to each sample in the longitudinal direction of the sample,
Annealing was performed in a nitrogen atmosphere at a maximum temperature of 260 ° C. to 360 ° C. for 10 minutes to 60 minutes. The saturated magnetic flux density Bs was measured with a VSM (vibrating sample magnetometer) after annealing. The measurement results of various characteristics are summarized in Table 1 together with Comparative Examples. All numbers are average values of 3 samples.

[0019]

[Table 1]

[0020]

[Table 2]

As is clear from Table 1, Sn,
The Fe-Co-Si-B amorphous alloy added with Cu or S has a high Bs of 1.7 T or more and B1 of 1.55 T or more, and W _16/50 of 0.3 W / kg or less. It can be seen that the iron loss at high magnetic flux density is lower than that of the conventional Fe-Co-Si-B amorphous alloy. Further, the amorphous alloy ribbon of the present invention has improved mechanical properties after annealing at the same time. On the other hand, the alloy having a composition outside the scope of the present invention does not reach the target of the present invention and has mechanical properties inferior to those of the present invention in either of amorphousness and soft magnetic characteristics at high magnetic flux density.

(Example 2) Alloy 1 of each composition shown in Table 3
kg was formed into an amorphous ribbon. Manufacture is performed by the multiple slit method (slit length 25 mm, to obtain a plate thickness of 40 μm or more,
The conditions are the same as in Example 1 except that a double slit nozzle having a width of 0.4 mm and a slit interval of 1 mm or a triple slit nozzle is used. After annealing this amorphous ribbon in the same manner as in Example 1, the core loss and magnetic permeability were measured with a single plate tester. The measurement results are shown in Table 3.

From Table 3, S of the present invention can be obtained even at a thick plate thickness.
Fe-Co-Si-B containing n, Cu, or S
Amorphous alloy is a conventional Fe-Co-
It can be seen that it has excellent characteristics as compared with the Si-B amorphous alloy. That is, when Sn, Cu, or S is not added or when these are below the lower limit of the present invention, the alloy having a large ferromagnetic metal content of 83 atomic% or more of the total content of Fe and Co has a plate thickness of 40 μm or more. However, the amorphization is incomplete and the soft magnetic properties are significantly deteriorated, but the alloy of the present invention retains excellent soft magnetic properties even at a plate thickness of 40 μm or more.

[0024]

[Table 3]

[0025]

As described above, the amorphous alloy ribbon of the present invention has a conventional F content known as a high magnetic flux density amorphous alloy.
e-Si-B amorphous alloy and Fe-Co-Si-B
Compared to amorphous alloys, the saturation magnetic flux density and magnetic permeability are high, and the iron loss at high magnetic flux density is low, so iron cores that require high saturation magnetic flux density and low loss, such as power transformers, choke coils, and aircraft transformers. Suitable for materials. In addition, since a thick plate can be easily obtained, it can be advantageously used in a magnetic shield material and a magnetic sensor.

[Brief description of drawings]

1 (a), (b), and (c) are basic components (Fe-
It is a figure which shows the influence which acts on iron loss when adding Sn, Cu, and S to Co-Si-B), respectively.

Claims (4)

[Claims] [Claim 1], wherein the composition is _{Fe a Co b Si c B d} M x, made with single-sided cooling method, low loss and high magnetic flux density amorphous alloy. However, M is Sn, Cu, S
A, b, c, d, and x are atomic%, 60 ≦ a ≦ 83, 3 ≦ b ≦ 20, and 80 ≦ a + b ≦ 86, 1 ≦ c ≦ 10, 11 ≦ d ≦ 16, x is Sn ≦ 0.1 ≦ x ≦ 1.0, Cu is 0.1 ≦ x ≦ 2.0, S is 0.01 ≦ x ≦ 0.07, and a + b + c + d + x = 100. 2. The low-loss, high-flux-density amorphous alloy according to claim 1, wherein a part of Si and B is replaced by C in a total amount of at most 4 atom%. 3. As a characteristic of the ribbon after annealing in a magnetic field measured at room temperature, the magnetic flux density when a magnetic field having a saturation magnetic flux density of 1.7 Tesla (T) or more and 1 Oersted (Oe) is applied is 1. 0.55 Tesla or more and 50 Hz, 1.
The low iron loss and high magnetic flux density amorphous alloy according to claim 1, wherein the iron loss at 6 Tesla is 0.30 W / kg or less. 4. The low iron loss / high magnetic flux density amorphous alloy according to claim 1, wherein the plate thickness is 40 to 100 μm.