JPH04341544A - Fe base soft magnetic alloy - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an Fe-based soft magnetic alloy, and particularly to an Fe-based soft magnetic alloy having good soft magnetic properties.

0002

[Prior art and problems to be solved by the invention] In recent years,
Fe-based amorphous magnetic alloys having high saturation magnetic flux density are widely known as magnetic core materials for high frequency transformers, saturable reactors, choke coils, and the like. However, Fe-based amorphous alloys generally have a large saturation magnetostriction constant, so if stress is applied after the core is fabricated, such as by resin impregnation or cutting, there are problems such as significant deterioration of soft magnetic properties, especially iron loss. there were.

The present invention aims to provide a novel Fe-based soft magnetic alloy that is a soft magnetic material that can replace such conventional Fe-based amorphous alloys and has excellent soft magnetic properties, particularly iron loss. do. Furthermore, the present invention provides a relatively low melting point F that can be easily manufactured using conventional magnetic material manufacturing equipment.
The object of the present invention is to provide an e-based soft magnetic alloy.

0004

[Means for Solving the Problems] In order to achieve the above object, the present inventor has carried out intensive research on Fe-based soft magnetic alloys, and as a result, has found that Al and Cu are added to Fe-Si-B alloys.
It was discovered that an alloy to which . That is, the Fe-based soft magnetic alloy of the present invention has the general formula (Fe1-
XMX) 100-a-b-c-dSiaAlbBcCu
d (in the formula, M represents Co and/or Ni; x represents the atomic ratio; a, b, c, and d represent atomic %; each 0≦x≦
0.5, 0≦a≦24, 1≦b≦20, 4≦c≦30,
0.2≦d≦3), and in particular, it is preferable that at least 30% of the structure is made of crystalline material, and this crystalline material is a BCC mainly composed of iron. It consists of a solid solution.

In the Fe-based soft magnetic alloy of the present invention, Fe
less than half of it can be replaced with Co and/or Ni. Al is an essential element of the alloy of the present invention, and Al has the effect of reducing the magnetocrystalline anisotropy of the crystals constituting the alloy of the present invention. The content of Al is 1 atomic % or more and 20 atomic % or less, preferably 4 to 12 atomic %. The reason for this is that by setting the Al content to 1 atomic % or more, the effect of reducing the crystal magnetic anisotropy of the precipitated crystals can be obtained, and by setting the Al content to 20 atomic % or less, the formation of an amorphous alloy is inhibited. There is no.

[0006] Cu has the effect of lowering the formation temperature of the Fe-based BCC solid solution and preventing coarsening of crystal grains. Its content is 0.2 to 3 at%. The reason for this is
This is because by setting Cu within such a range, the desired effect can be obtained without deteriorating the magnetic properties. The alloy of the present invention is produced by crystallizing it from an amorphous state through heat treatment, and B is an element that causes the Fe-based alloy of the present invention to become amorphous by rapidly cooling it. The content of B is 4 to 30 at%, preferably 6 to 18 at%. By setting B to 4 atomic % or more, the alloy of the present invention can be made amorphous. In addition, by controlling B to 30 atomic % or less, it is possible to suppress the tendency that when crystallizing from an amorphous state by heat treatment, a large number of Fe-B compounds precipitate due to too much B and the soft magnetic properties deteriorate. can. The content of Si is 0 to 24 atomic %, and preferably 24 atomic % or less to lower the saturation magnetostriction.

The basic composition of the Fe-based soft magnetic alloy of the present invention is the above-mentioned Fe(M)-B, Si, Al, and Cu.
Furthermore, other elements M' can be added to improve corrosion resistance and the like. M' is Pd, Ru, Ga, Cr
, Y, W, Nb, Ta, Ge, C, and P. These elements are contained in an amount of 10 atomic% or less,
Preferably, it is added in an amount of 5 atomic % or less.

The Fe-based soft magnetic alloy of the present invention contains Al and Cu.
By containing in a predetermined proportion, fine crystal grains with extremely small magnetocrystalline anisotropy and saturation magnetostriction are formed. The grain size is preferably 1000 angstroms or less, and preferably 500 angstroms or less in order to obtain good soft magnetic properties. In addition, the structure is mainly composed of crystalline and amorphous materials, but since the amorphous portion has a larger magnetostriction than the crystalline portion, at least 30% or more of the entire structure, preferably 60% or more, is crystalline. and the remainder is preferably amorphous. In addition, in the present invention, the size of crystal grains,
The degree of crystallinity (crystallinity) was determined by electron microscopy diffraction method and
Determined by line diffraction method.

The Fe-based soft magnetic alloy of the present invention can be obtained by first preparing an amorphous ribbon, powder, fine wire, thin film, etc., and then heat-treating the obtained amorphous alloy. In the case of a ribbon, a sample prepared by a single roll method or the like is formed into a predetermined shape such as a wound core, and then heat-treated at about 400 to 700°C. A magnetic field may be applied during the heat treatment. Further, the heat treatment may be performed in any atmosphere of nitrogen gas, argon gas, or vacuum.

[0010] Hereinafter, further explanation will be given with reference to examples.

[0011]

[Example] Using a single roll method, Fe, Si, Al, B
, width 3 in an argon gas atmosphere from a Cu-containing alloy.
A quenched ribbon having a thickness of about 18 μm and a thickness of about 18 μm was prepared. Table 1 shows the composition and crystallization temperature of this quenched ribbon.

0012

[Table 1]

[0013] As is clear from Table 1, the addition of Cu
It can be seen that this has the effect of lowering the crystallization temperature of the amorphous ribbon (accelerating the precipitation of crystal grains). Next, the X of this thin strip
The line diffraction pattern is shown in Figure 1. As is clear from FIG. 1, the ribbon immediately after production exhibits a halo pattern characteristic of an amorphous alloy, which indicates that its structure is amorphous.

[0014] Next, the obtained ribbon has an inner diameter of 15 mm and an outer diameter of 1
After making a wound core of about 8 mm, it was heated for 500 min in a nitrogen gas stream.
After being maintained at °C for about 1 hour, it was cooled in a nitrogen stream. At this time, no magnetic field was applied. The X-ray diffraction pattern after this heat treatment is shown in FIG. In the ribbon after heat treatment, Fe-based bc
c Diffraction peaks of solid solution crystals were observed. Core loss (
W/kg) at a frequency of 100kHz and a maximum magnetic flux density of 0.
It was determined from the area surrounded by an AC hysteresis loop measured using a digital oscilloscope at 1T. The saturation magnetostriction constant λS (ppm) was determined by the strain gauge method. The results are shown in Table 2.

[0015]

[Table 2]

As is clear from Table 2, the increase in core loss due to impregnation in the magnetic core of the example is much smaller than that of the conventional Fe-based amorphous alloy (comparative example). This result corresponds to the fact that the saturation magnetostriction of the magnetic alloy of the present invention is also about one order of magnitude smaller than that of the conventional Fe-based amorphous alloy. From the above, it has become clear that the alloy of the present invention exhibits very little deterioration in magnetic properties during the impregnation process.

[0017]

Effects of the Invention As is clear from the above examples, the Fe-based soft magnetic alloy of the present invention has excellent soft magnetic properties by adding Al and Cu to the Fe-Si-B alloy. A new Fe-based soft magnetic alloy can be obtained. Furthermore, since the Fe-based soft magnetic alloy of the present invention exhibits low magnetostriction, the increase in core loss after impregnation is small, making it suitable as a magnetic core material.

[Brief explanation of drawings]

FIG. 1 is a diagram showing an X-ray diffraction pattern of the Fe-based soft magnetic alloy ribbon of the present invention immediately after quenching.

FIG. 2 is a diagram showing the X-ray diffraction pattern of the Fe-based soft magnetic alloy ribbon of the present invention after optimum heat treatment.

Claims (3)

[Claims] Claim 1: General formula (Fe1-XMX) 100-a-b
-c-dSiaAlbBcCud (In the formula, M represents Co and/or Ni. x represents the atomic ratio, and a, b, c, and d represent atomic %, respectively, 0≦x≦0.5, 0≦a≦ 2
4, 1≦b≦20, 4≦c≦30, 0.2≦d≦3). 2. The Fe-based soft magnetic alloy according to claim 1, wherein at least 30% of the structure is crystalline and the remainder is amorphous. 3. The Fe-based soft magnetic alloy according to claim 2, wherein the crystalline material is a BCC solid solution mainly composed of iron.