JPH0790515A - Iron-base amorphous alloy increased in magnetic flux density and reduced in iron loss - Google Patents

Abstract

PURPOSE:To produce an iron-base amorphous alloy increased in magnetic flux density and reduced in iron loss by preparing an iron-base amorphous alloy consisting of specific percentages of Fe, B, Si, Mn, and Co. CONSTITUTION:An iron-base amorphous alloy having a composition represented by chemical formula FexBySizMnaCob is prepared. In this formula, x=70 to 80%, by atom, y=7 to 15%, z=4 to 17%, a=0.2 to 3%, b=5 to 10%, and x+y+z+a+b:100. By this method, the iron-base amorphous alloy, improved in magnetic flux density and reduced in iron loss to a greater extent, can be produced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an iron-based amorphous alloy having a high magnetic flux density and a low iron loss, and is particularly suitable for use as a soft magnetic material for transformers.

[0002]

2. Description of the Related Art JP-A-54-148122 and JP-A-55-94
As reported in Japanese Patent No. 60, when a Fe-B-Si-based molten alloy is rapidly solidified by a single roll method or the like at a cooling rate of about 10 ⁵ to 10 ⁶ ° C / s, the plate thickness is several tens of μm. Below, a so-called amorphous alloy ribbon in which the atomic arrangement is disordered is obtained. Since such a ribbon is excellent in soft magnetism, it has been partially put into practical use as a transformer material.

Further, Japanese Unexamined Patent Publication (Kokai) No. 63-317639 proposes an amorphous metal mainly composed of Co, Si and B. This amorphous metal has a plate thickness of 10 μm or less especially for high frequency applications. It is thin and has high magnetic permeability. Further, in Japanese Patent Laid-Open No. 61-136660, an amorphous alloy in which Mn or the like is added to the Fe-B-Si system in a certain range to improve the insulating coating processability while maintaining low iron loss is also disclosed. Proposed.

Furthermore, Japanese Patent Laid-Open No. 192560/1987 discloses that
Fe-B-Si system with Cr, Mo, Ta, Mn, Ni, Co, V, Nb, W
One or more selected from the above are added to 0.05 to 5 at% to improve the workability so that the average roughness of the surface is 0.4 μm or less and the space factor is improved. Is proposed.

[0005]

[Problems to be Solved by the Invention] However, Fe-B-Si
In the ternary amorphous alloy ribbon, although a somewhat low iron loss value can be obtained, there is a problem that it is difficult to obtain a lower iron loss in the ternary system. However, Mn is added to the Fe-B-Si system.
When added, a new problem arises that the magnetic flux density decreases. On the other hand, although the Co-B-Si system has a significantly improved magnetic permeability as compared with the Fe-B-Si system, it has a problem of low magnetic flux density and is expensive.

The present invention relates to improvement of an Fe-B-Si-based amorphous alloy, and particularly to an iron-based amorphous material in which the magnetic flux density is improved without being lowered, and further the iron loss is further reduced. The purpose is to propose an alloy.

[0007]

Means for Solving the Problems Now, as a result of intensive studies to achieve the above object, the inventors have found that an appropriate amount of Mn is added to an Fe-B-Si system which is an amorphous alloy with low iron loss. It was discovered that iron loss can be further reduced by adding Co, and at the same time, an appropriate amount of Co can be added to effectively prevent the decrease in magnetic flux density that could not be avoided only by adding Mn, and rather to improve it. Obtained. The present invention is based on the above findings.

Namely, the present invention has the _{formula: Fe x B y Si z Mn} a Co b wherein x: 70~80at%, y: 7~15at %, z: 4~17a
An iron-based amorphous alloy having a high magnetic flux density and a low iron loss, which has a composition represented by t%, a: 0.2 to 3 at%, b: 5 to 10 at%, x + y + z + a + b = 100 at%.

[0009]

The reason why the composition of the amorphous alloy is limited to the above range in the present invention will be described below. Fe 70
The reason for setting the content to -80 at% is that if it is less than 70 at%, the magnetic flux density is too low to be practical, and if it exceeds 80 at%, it becomes difficult to amorphize and the iron loss increases.
If B is set to 7 to 15 at%, not only is it difficult to amorphize if less than 7 at%, but also iron loss is increased. On the other hand, if it exceeds 15 at%, Fe is relatively decreased and the magnetic flux density is increased. Because it will decrease. The reason why Si is set to 4 to 17 at% is that when it is made amorphous by only B, it lacks thermal stability. Therefore, at least 4 at% of Si must be added to avoid this, while if it exceeds 17 at%. This is also because Fe is relatively reduced and the magnetic flux density is lowered.

In the present invention, it is important to add an appropriate amount of Mn and an appropriate amount of Co to the above Fe-B-Si system at the same time. Is further reduced. Mn is
It effectively contributes to the reduction of iron loss of Fe-B-Si based amorphous alloys, but if it is less than 0.2 at%, its improving effect is poor.
If the content exceeds 3.0 at%, the decrease in magnetic flux density cannot be avoided even by the simultaneous addition of Co described later, so the Mn content was limited to the range of 0.2 to 3.0 at%. Co is a useful element that can effectively prevent the decrease in magnetic flux density that cannot be avoided only by adding Mn, and can rather improve it, but if the content is less than 5.0 at%, its addition effect is poor, on the other hand
If it exceeds 10.0 at%, not only the effect of improving the magnetic flux density is weakened but also the iron loss is increased, and Co is also expensive, so the content is made to be in the range of 5.0 to 10.0 at%.

[0011] Figure 1, as a result of the _{Fe 78-a B 13 Si 9} Mn a becomes amorphous alloy composition was investigated for changes in B ₁₀ (the magnetic flux density in the 1000A / m becomes magnetic field) with respect to the Mn content a Indicates.
For comparison, the figure also shows the results of an investigation on an amorphous alloy having a composition of Fe _72-a B ₁₃ Si ₉ Mn _a Co _{6 in} which _a portion of Fe _78-a was replaced with Co. As is clear from the figure, Fe−
When Mn was added to the B-Si system alone, B ₁₀ decreased with the increase of Mn content, but when Co was added together, B ₁₀ was remarkably improved, and when Mn was added alone. Similarly, although the content of B ₁₀ is somewhat reduced with the increase of the Mn content, it does not fall below the original B ₁₀ of the Fe-B-Si system within the content of 3.0 at%.

Next, FIG. 2 shows the results of investigating the change of the iron loss value with respect to the Mn addition amount a for the amorphous alloy having the same composition of Fe _78-a B ₁₃ Si ₉ Mn _a . For comparison, in the figure, Fe _72-a B ₁₃ Si ₉ Mn _a Co in which _a part of Fe _78-a is replaced with Co is shown.
_The results of investigations on amorphous alloys with ₆ compositions are also shown.
As is clear from the figure, the amount of Mn was 0.2 to 3.0 at% in both cases of single addition of Mn and combined addition of Mn and Co.
In the range of 1, the iron loss is significantly improved.

Further, FIG. 3 shows the results of examining the change of the iron loss value with respect to the Co addition amount b for the amorphous alloy having the composition of Fe _78-b B ₁₃ Si ₉ Co _b . In the figure, for comparison, Fe _78-b partially replaced with Mn is Fe _77.5-b B ₁₃ Si ₉ M.
The results of investigations on amorphous alloys with a composition of n _0.5 Co _b are also shown. As is clear from the figure, good iron loss was not obtained when Co was added alone, but a marked reduction in iron loss was achieved when Mn was added in combination.

[0014]

[Examples] The molten alloys melted in various compositional compositions shown in Table 1 were injected onto the surface of a Cu roll rotating at a high speed, and the thickness:
After making an amorphous alloy ribbon of 25 μm and width: 10 mm, 375
Annealing was performed in a magnetic field at 1 ° C. for 1 hour. The results of measuring the iron loss value and magnetic flux density of each amorphous alloy ribbon thus obtained,
It is also shown in Table 1.

[0015]

[Table 1]

As is clear from the table, all the amorphous alloys whose composition was adjusted according to the present invention have low iron loss,
The magnetic flux density is also high. On the other hand, all the comparative examples in which the component composition deviates from the proper range of the present invention,
Either the magnetic flux density or the iron loss was bad, and neither excellent alloy ribbon could be obtained.

[0017]

Thus, according to the present invention, Fe-B-Si
The magnetic flux density of the ternary amorphous alloy can be improved rather than lowered, and iron loss can be significantly reduced.
For example, when it is used as a material for a transformer, not only the characteristics thereof can be improved, but also the size can be reduced.

[Brief description of drawings]

FIG. 1 is a graph showing changes in magnetic flux density due to addition of Mn.

FIG. 2 is a graph showing changes in iron loss due to addition of Mn.

FIG. 3 is a graph showing changes in iron loss due to addition of Co.

Claims (1)

[Claims] 1. A chemical _{formula: Fe x B y Si z Mn} a Co b wherein x: 70~80at%, y: 7~15at %, z: 4~17a
An iron-based amorphous alloy having a high magnetic flux density and a low iron loss, which has a composition represented by t%, a: 0.2 to 3 at%, b: 5 to 10 at%, and x + y + z + a + b = 100 at%.