JPH055162A - Soft magnetic alloy high in magnetic permeability - Google Patents

Abstract

PURPOSE:To obtain a magnetic alloy having high magnetic permeability by low Ni content by adding Cr to an Ni-Fe alloy so as to make it into an Ni-Cr- Fe alloy having a specified compsn. CONSTITUTION:The ingot of an Ni-Cr-Fe alloy having a compsn. constituted of, by weight, 30 to 55% Ni, <14% Cr and the balance Fe is worked into a sheet by hot rolling and cold rolling. A magnetic allay having a texture in which the integrated intensity in the {200} plane contg. the axis of easy magnetization is integrated in the plane by double or above compared to that in the {200} plane of a random sample obtd. by subjecting alloy powder by a gas atomizing method having the same compsn. to compacting and sintering, in which all crystal planes have been appeared in an equal ratio and having no crystalline orientation and having high magnetic permeability of >=100000mum maximum magnetic permeability can be obtd. An inexpensive magnetic alloy having expensive Ni content lower than that of the conventional high Ni permalloy can be obtd.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic alloy having a high magnetic permeability, having a maximum magnetic permeability μ _m of 100,000 or more, which is used for magnetic shield members, various iron cores and the like which are required to have high magnetic permeability.

[0002]

2. Description of the Related Art Ni-Fe alloys are widely used as magnetic shield members such as magnetic head case materials, cassette tape magnetic shielding materials, and iron core materials for various electric devices. Typical materials belonging to this system are Mo and C
There is a high Ni permalloy (JIS-PC) containing r, Cu and the like. High Ni permalloy exhibits high magnetic permeability and high corrosion resistance, but it is expensive because it contains more than 70% by weight of Ni and Mo. Therefore, high Ni
The use of permalloy is subject to economic constraints.

Further, instead of expensive high Ni permalloy,
Low Ni with a relatively low Ni content of about 45% by weight
Permalloy (JIS-PB) is used. Low Ni
Permalloy has a high saturation magnetic flux density B ₁₀ of 15,000 G, but is extremely inferior in inductance permeability μ _L to high Ni permalloy. Therefore, high Ni permalloy is still unavoidable for applications requiring high magnetic properties.

For these reasons, it has been desired to develop an inexpensive soft magnetic alloy having a magnetic characteristic comparable to that of high Ni permalloy and having low Ni permalloy or lower. In order to meet this demand, the present inventors have developed a soft magnetic alloy with improved saturation magnetic flux density and inductance permeability by containing Ni and Cr in a specified ratio, and Japanese Patent Application No. 1-227445, Japanese Patent Application 2-78
Filed as No. 215, etc.

When Cr is added to a Ni-Fe alloy,
The saturation magnetostriction constant λ _s and the magnetic anisotropy constant K ₁ approach 0. The Curie point T _c also decreases to near room temperature as the Cr content increases. Then, the Hopkinson effect in which the magnetic permeability is improved in the vicinity of the Curie point is shown. As a result, C
It is assumed that the addition of r improves the magnetic permeability.

[0006] The Ni-Fe based alloy containing Cr has a higher initial magnetic permeability than 45% permalloy (JIS-PB), which is a typical inexpensive Ni-Fe based soft magnetic alloy. It exhibits magnetic characteristics comparable to 80% Ni permalloy (JIS-PC) containing Cu and the like. Moreover, since it does not contain a large amount of Ni, it is an inexpensive material. From this advantage, it is a promising material as various magnetic core materials such as magnetic shield members such as case materials and cover materials for magnetic heads, and stator materials and core materials.

[0007]

As described above, the Ni--Cr--Fe alloy material is reduced in the saturation magnetostriction λ _s , the magnetic anisotropy K ₁ and the Curie point to near room temperature. Magnetic properties are improved. Further, the magnetic characteristics can be improved by controlling the content of impurities to reduce the amount of non-metallic inclusions that hinder the movement of the domain wall and by aligning the crystal orientations in the easy magnetization direction. Further, the magnetic characteristics are also improved by reducing the mechanical strain and facilitating the movement of the domain wall.

However, many conventional means for improving magnetic properties have been obtained empirically, and special component design, processing, heat treatment, etc. are performed for each alloy material. These means and combinations thereof are complicated and diversified and lack versatility. In order to stably obtain a material having excellent magnetic properties, a special technique that has not been generalized is required.

The present invention has been devised to solve such a problem, and provides a Ni-Cr-Fe based soft magnetic alloy having a stable and high magnetic permeability by devising a crystal orientation. The purpose is to do.

[0010]

The Ni-Cr-F of the present invention
The e-based soft magnetic alloy has a content of 30 to
It contains 55% by weight of Ni and 14% by weight or less of Cr, and the integrated strength of the {200} plane including the easy axis of magnetization <100> has a crystalline orientation of {20}.
It is characterized by having an in-plane aggregated texture that is more than twice the integrated intensity of the 0} plane.

Here, the random sample is produced by pulverizing an alloy having the same components and compositions by a gas-atomizing method and compacting and sintering the obtained alloy powder. In the random sample, all the crystal planes appear at the same rate and have no crystal orientation. On the other hand, in the alloy according to the present invention, since the integrated strength of the high index plane is so weak as to be negligible, it is almost {200}, {220},
It can be considered that it is composed of four planes of {111} and {311}. Integrated intensity I ₀ of {200} plane of random sample
The ratio I of the integrated intensity I of the {200} plane of the sample of the present invention to
/ I ₀ is referred to as an integrated intensity ratio in the following description.

[0012]

Function: The easy axis of magnetization of the Ni-Cr-Fe alloy is <10.
0>. It is expected that the magnetic properties will be improved as the direction of the easy axis <100> is aligned. In the present invention, when a {200} plane containing a large number of easy magnetization axes <100> is in-plane integrated at a rate twice or more that of a random sample, an interesting phenomenon that magnetic permeability is dramatically improved was found. The easy axis of magnetization <100> is another low index plane {220},
Although it is included in {111}, {311}, etc., {200}
Even if the planes other than the planes are integrated in-plane, the same improvement in magnetic permeability is not observed.

The in-plane accumulation of the {200} plane is influenced by the component design, the regulation of the content of impurities, the processing conditions, the heat treatment conditions, etc., and each condition cannot be uniquely defined. However, these conditions are preferably selected within the range described below.

Component design: To increase the degree of in-plane integration of the {200} plane and obtain the required residual magnetic flux density and maximum magnetic permeability, Ni is contained in an amount of 30 to 55% by weight. When the Ni content is less than 30% by weight, the magnetic permeability is lowered.
On the contrary, when the Ni content exceeds 55% by weight, the conventional high N
iPermalloy will be less advantageous in terms of price.

Further, in order to improve the magnetic permeability and the coercive force, the Cr content is set to 14% by weight or less. More specifically, Ni-Cr-F containing 35-40 wt% Ni.
In an e-based alloy, 3 × (Ni%) − 5 × (Cr%) ≦ 80
Under these conditions, 5 to 14% by weight of Cr is contained. Also, 4
In a Ni-Cr-Fe alloy containing 0 to 52% by weight of Ni, 5% by weight or less of Cr is added under the condition of 50 ≦ (Ni%) + 4 × (Cr%) ≦ 60.

Impurity content: Mn, Si, S, O, P, A as impurities contained in the Ni-Cr-Fe alloy.
There is l etc. These impurities are dispersed in the matrix as non-metallic inclusions, for example, and become a factor that hinders the movement of the domain wall. In order to suppress this adverse effect, Mn ≦ 0.8
0% by weight, Si ≦ 0.30% by weight, S ≦ 0.0030% by weight, O ≦ 0.0050% by weight, P ≦ 0.03% by weight,
Impurities are regulated so that Al ≦ 0.30% by weight. Such reduction of the impurity content can be easily achieved by ordinary vacuum scouring.

Processing conditions: When cold rolling before magnetic annealing is carried out at a large rolling rate, the fibrous hot rolled texture is destroyed,
A cold rolled structure mainly composed of {001} <211> and {211} <111> is formed. This cold-rolled structure plays an important role in improving the in-plane integration degree of the {200} plane grown by magnetic annealing. Further, the hot rolling is preferably performed by heating to a high temperature of 1050 ° C. or higher so that this cold rolled structure is easily formed.

Heat treatment: The intermediate annealing carried out during the cold rolling is intended to remove work strains and the like caused by cold rolling, but it is 750 to 1100 in a non-oxidizing atmosphere.
It is preferable to perform the intermediate annealing at ℃. Magnetic annealing also prevents precipitation of non-metallic inclusions and {200}
In order to improve the degree of in-plane integration of the surface in H ₂ gas or H
It is preferable to perform it in a _2- N ₂ mixed gas at a high temperature of 1000 ° C. or higher.

FIG. 3 shows a plane extension cubic structure which is a crystal model of the alloy system of the present invention. In this alloy system, the easy axis of magnetization is <
The {200} plane, which is known to be 100>, is
It includes two 100> axes, and has the largest axis of easy magnetization. As far as the low index plane is concerned, the {220} plane includes one easy axis <100>, and the {111} plane and the {311} plane do not include the easy axis <100>. Therefore, in order to improve the magnetic permeability, it is advantageous to integrate {200} planes containing a lot of the easy axis <100>, and the magnetic permeability improves as the integrated intensity ratio of the {200} planes increases.

This means that, as shown in comparison with (a) and (b) of FIG. 1, there is a peak of the integrated intensity ratio of the {200} plane in all of 1% Cr, 3% Cr and 5% Cr. It is also clear from the fact that the peak of maximum magnetic permeability μ _m coincides with the Ni content. The in-plane integration degree of the {200} plane in FIG. 1 is represented by the integrated intensity ratio with respect to the random material.

[0021]

EXAMPLES The present invention will be specifically described below with reference to examples. [Example 1] An alloy having the composition shown in Table 1 was vacuum melted, and the obtained ingot was subjected to hot rolling and cold rolling at a rolling rate of 80% to produce a cold rolled sheet having a sheet thickness of 0.5 mm. did.
In the middle of cold rolling, intermediate annealing was performed once by heating at 900 ° C for 1 minute. The test numbers 1 to 5 are materials for obtaining the in-plane integration degree of the {200} plane defined in the present invention, and the test numbers 6 and 7 are out of the scope of the present invention {20.
It is a comparative material for obtaining the in-plane integration degree of the 0} plane.

[0022]

[Table 1]

An annular test piece having an outer diameter of 45 mm and an inner diameter of 33 mm was cut out from the cold rolled sheet. Magnetic annealing was performed by heating each test piece in a hydrogen atmosphere at 1100 ° C. for 1 hour. For each test piece after magnetic annealing, initial permeability μ _i , maximum permeability μ
_m , coercive force H _c, and inductance permeability μ _L at 1 kHz were measured. The texture corresponding to each test piece after magnetic annealing was measured by the characteristic X-ray of Mokα.
Table 2 also shows the integrated intensity ratio of the {200} plane.

[0024]

[Table 2]

As is clear from Table 2, in Test Nos. 1 to 5 in which the {200} plane has a high degree of in-plane integration, excellent magnetic properties with a maximum magnetic permeability μ _m ≧ 100,000 are shown. And the inductance permeability μ _L is also high. Further, the coercive force H _c also decreases as the in-plane integration degree increases. On the other hand, in test numbers 6 and 7 in which the degree of in-plane integration of the {200} plane is low, 50,000 or 65.0
Only the maximum magnetic permeability μ _{m of} about 00 is obtained, and the inductance magnetic permeability μ _L also shows a low value of 4800 or 3900 or less.

[Example 2] The annular test pieces cut out from the alloys of Experiment Nos. 1 to 3 used in Example 1 were magnetically annealed at various annealing times and annealing temperatures for {20.
0} planes having different in-plane integration degrees were manufactured. And
The maximum magnetic permeability μ _m of each test piece after annealing was measured, and the relationship with the in-plane integration degree was investigated. The survey results are shown in FIG.

As is apparent from FIG. 2, the maximum magnetic permeability μ _m sharply increases at the boundary of the integrated intensity ratio 2 of the {200} plane. That is, when magnetic annealing is performed under the condition that the integrated intensity ratio is 2 or more, the maximum magnetic permeability μ _m ≧ 10
10,000 soft magnetic alloys have been obtained. On the other hand, even when alloy materials having the same composition are used, when the integrated strength ratio does not reach 2, the maximum magnetic permeability μ _m is low,
It cannot be used as a substitute for high Ni permalloy.

In this example, the in-plane integration degree of the {200} plane was controlled under the annealing conditions. However, the present invention is not restricted to this, and it goes without saying that the in-plane integration degree of the {200} plane can be controlled by combining the component design, the impurity regulation, the processing conditions or the heat treatment conditions as described above. is there.

[0029]

As described above, in the present invention, by setting the in-plane integration degree of the {200} plane to be 2 or more in terms of the integrated intensity ratio, 100,000 which is comparable to high Ni permalloy JIS-PC. Or higher maximum permeability μ
A soft magnetic alloy showing _m is obtained. Moreover, since this soft magnetic alloy does not contain a large amount of expensive Ni, it can be provided at a relatively low cost. From the viewpoint of such excellent magnetic properties and price, the Ni-Cr-F of the present invention is used.
The e-based soft magnetic alloy is a promising material to replace high Ni permalloy.

[Brief description of drawings]

1] In-plane integration degree of {200} plane and maximum magnetic permeability μ _m
Graph showing that a close relationship has been established between

2] The in-plane integration degree of {200} plane is maximum magnetic permeability μ _m
Graph showing the effect on

FIG. 3 Model for explaining crystal orientation

Continuation of the front page (51) Int.Cl. ⁵ Identification number Reference number within the agency FI Technical indication location H01F 1/14 H05K 9/00 H 7128-4E (72) Inventor Yu Kawai 4976 Nomura Minamimachi, Shinnanyo, Yamaguchi Prefecture Nisshin Steel Co., Ltd.

Claims (1)

Claims: 1. 30 to 55% by weight of Ni and 14% by weight.
If the integrated strength of the {200} plane containing the following Cr and including the easy axis <100> is more than twice the integrated strength of the {200} plane of a random sample having crystal orientation, A Ni-Cr-Fe based soft magnetic alloy having a high magnetic permeability characterized by having an integrated texture.