KR0131376B1 - Fe-bane soft magnetic alloy & process for making same - Google Patents

Abstract

As a novel Fe-based soft magnetic alloy having excellent soft magnetic properties, in particular, low magnetic deformation and low iron loss, an alloy is prepared by adding a predetermined amount of a specific element M, preferably Zr, and the like, and a predetermined amount of Cu. Add more. The quench alloy having such a composition may be formed into a ribbon, powder, or thin film, and then heat-treated to provide a Fe-based soft magnetic alloy in which at least 30% of the tissue constitutes fine crystal grains.

Description

Fe-based soft magnetic alloy and preparation method thereof

1 is a graph showing an X-ray diffraction pattern after heat treatment of the Fe-based soft magnetic alloy of the present invention.

The present invention relates to a Fe-based soft magnetic alloy, and more particularly, to an alloy having excellent soft magnetic properties and a method of manufacturing the same.

Fe-based amorphous magnetic alloys having a high saturation magnetic flux density are known to be used as magnetic core materials such as magnetic heads, high frequency transformers, saturation functional reactors, and choke coils. However, Fe-based amorphous magnetic alloys are more inexpensive than Co-based, but have the disadvantage that electrons have a high core loss and a low permeability in the high frequency region. In addition, his saturation magnetostriction is high.

Fe-B based alloys are known as conventional Fe-based amorphous magnetic alloys. However, alloys containing B (boron) are expensive because element B is expensive.

One object of the present invention is to provide a novel Fe-based soft magnetic alloy which can replace the conventional soft magnetic material described above, and which has a low saturation magnetic deformation and low breakage.

Another object of the present invention is to provide a low cost Fe-based soft magnetic alloy.

In view of the above-mentioned objectives, the results of steady research on various Fe-based soft magnetic alloys have shown that Fe-P-based and Fe-based soft magnetic alloys have improved twisted-magnetic properties with excellent soft magnetic properties when certain elements (M), especially Zr, are added. It has been found that it is possible to provide a base Fe—Si—B—A 1 soft magnetic alloy and to add Cu to a Fe—PM based Fe—based soft magnetic alloy effectively to obtain an excellent soft magnetic alloy.

Specifically, according to the present invention, an Fe-based soft magnetic alloy having the composition represented by the following formula is provided.

Fe _100-abcd P _a M _b M ' _c Cu _d

Wherein M is at least one element selected from the group consisting of Zr, Hf, Nb, Mo, W, Ta, Ti, V, Cr, Mn, Y and Ce, and M 'is Si, Al, Ga, Ge, Ru At least one element selected from the group consisting of Co, Ni, Sn, Sb and Pd, a, b, c and d are each atomic% and each 0a≤25, 0b≤15, 0≤C≤20, 0≤d ≤ 5 is satisfied. In particular, it is preferable that at least 30% of the alloy structure is occupied by fine crystal grains, and the fine crystal grains are composed of a bcc solid solution mainly containing Fe.

P is an essential element constituting the alloy of the present invention, and when P is added in a specific amount (0 atomic% or more and 25 atomic% or less), the formation range of the amorphous alloy after quenching is expanded without using expensive element B (boron). It is possible. Thereby, the manufacturing cost of an alloy can be reduced.

The content (a) of P is preferably 0 atomic% or more, 25 atomic% or less, preferably 1 to 15 atomic%, and more preferably 2 to 12 atomic%.

The element (s) M added to the Fe-based soft magnetic alloy of the present invention is supposed to suppress the precipitation of Fe-P-based crystals that do not harm the soft magnetic properties of the alloy or to raise the precipitation start temperature to a high temperature. As M, at least one of the elements selected from the group consisting of Zr, Hf, Nb, Mo, W, Ta, Ti, V, Cr, Mn, Y and Ce is used. Among these, Zr is particularly preferable. The addition of element (s) M is effective in miniaturizing crystal grains and improving the ability to form amorphous alloys in Fe—P based alloys.

The content (b) of the element M is 0 to 15 atomic%, preferably 2 to 15 atomic%, more preferably 3 to 12 atomic%.

The element (s) M 'added to the Fe-based soft magnetic alloy of the present invention is at least one element selected from the group consisting of Si, Al, Ga, Ge, Ru, Co, Ni, Sn, Sb and Pb. These elements are considered to be employed in a solid solution mainly composed of Fe. Because their elements are negative in terms of their mutual parameters with Fe. That is, the elements are considered to be dissolved to stabilize the bcc crystal because they are substituted at the Fe atom position of the α-Fe crystal structure. Therefore, since the crystal grains having the intrinsic crystallite anisotropy or the low-molecular strain constant of the bcc crystal are formed, it is considered to exhibit excellent soft magnetic properties.

The content (C) of the M 'element (s) is preferably 0 to 20 atomic%, preferably 1 to 15 atomic%.

In the alloy of the present invention, Cu (copper) is effective for atomization of crystal grains obtained by amorphous heat treatment. In addition, the magnetic properties of the alloy can be improved because the effective magnetic anisotropy energy when the particles are granulated is smaller than the intrinsic magnetic crystal anisotropy energy. However, since the alloy after quenching tends to crumble, the copper content should not be more than 5 atomic% for the production of the alloy. Therefore, the content d of Cu is 0 to 5 atomic%, preferably 0.5 to 3 atomic%.

Incidentally, alloys which inevitably further contain impurities such as N, S, O and the like to the extent that these elements do not deteriorate the properties of the alloy also fall within the scope of the present invention.

In the Fe-based soft magnetic alloy according to the present invention, at least 30% (30-100%) of the entire structure constitutes fine crystal grains, and portions other than the above-described crystal grains are crystalline or amorphous other than the above-mentioned microcrystals. When the ratio of the fine crystal grains in the structure is within the above range, it is possible to provide an alloy having excellent soft magnetic properties. In the present invention, even though the crystal grains occupy substantially 100% of the structure, the alloy still has sufficiently good magnetic properties. Preferably, in terms of magnetic properties, fine crystal grains constitute at least 50%, more preferably 70% or more of the alloy structure.

It is estimated that the crystal grains of the alloy of the present invention mainly have a bcc structure, and M, M 'and a small amount of P are dissolved with Fe as a main component.

The crystal grains to be formed into the alloy of the present invention provides an alloy having an average particle diameter of 1000 Å or less, preferably 500 Å or less, more preferably 5 to 300 Å and having excellent magnetic properties of the present invention.

In the preferred Fe-based soft magnetic alloy of the present invention, the saturation magnetostriction constant (λ _S ) is + 10 × 10 ^{−5 to} 5 × 10 ⁻⁶ .

In the alloy of the present invention, the ratio of crystal grains and total alloy structure can be experimentally evaluated by X-ray diffraction or the like. In short, the ratio between the reference value and the X-ray diffraction intensity of the magnetic alloy material sample to be measured based on the X-ray diffraction intensity of the Fe-based crystal in the fully crystallized state (the state where the X-ray diffraction intensity is saturated). Can be evaluated by experiment.

The average particle diameter of the crystal grains is derived from the Scheller's equation (t = 0.9λ / β cosθ) using bcc peak reflection of the X-ray diffraction pattern (X-ray diffraction element (second edition), 91, 94, B, D, Cullity)

The Fe-based soft magnetic alloy having the microcrystalline particles of the present invention can be produced by heat-treating an alloy obtained by a conventional method for forming an amorphous metal. For example, first, an amorphous alloy is formed into a ribbon, powder, fiber, or thin film by a liquid forming method such as a single roll method or a twin roll method, a thin film forming method such as a vacuum method, a sputtering method or a vacuum deposition method or a powder forming method such as mechanical alloying. Next, the amorphous alloy obtained can be optionally processed into a desired shape, and then subjected to heat treatment to crystallize at least a portion, preferably at least 30% of the entire sample, to obtain the alloy of the present invention.

Although the alloy structure after quenching is preferably good in amorphous state, some crystals may be mixed as long as it exhibits soft magnetic properties after heat treatment.

In general, the quenched alloy ribbon is formed by a single roll method, and then formed into a predetermined shape such as a winding core, followed by heat treatment. The heat treatment is performed in a vacuum, in an inert gas atmosphere such as argon gas or nitrogen gas atmosphere, in a reducing gas atmosphere such as H ₂ or in an oxidizing gas atmosphere such as air. Preferably, it is performed in a vacuum or inert gas atmosphere. The heat treatment temperature is about 200 to 800 ° C, preferably about 300 to 700 ° C, more preferably 350 to 700 ° C, more preferably 400 to 700 ° C. The heat treatment time is within 24 hours, preferably about 0.5 to 5 hours. The heat treatment can be performed either in the absence of magnetic field or in the magnetic field. Magnetic anisotropy can be provided to the alloy by applying a magnetic field.

By heat-treating the amorphous alloy within the above-described temperature range and the above-mentioned time range, a soft magnetic alloy having excellent characteristics is obtained.

Example

Embodiments of the present invention will be described below.

Examples 1-3

After forming a quenched ribbon (thin film) sample having a width of about 1.5 mm and a thickness of about 15 to 24 μm in a capacity containing Fe, P, Zr, and Cu in a single atmosphere of argon gas atmosphere by a single roll method. The sample was heat-treated at a temperature shown in Table 1 for about 1 hour in a magnetic field containing nitrogen gas.

Iron loss (Pc W / kg) of each sample was measured at a frequency of 100KH _z and a maximum magnetic flux density of 0.1T. The effective magnetic permeability (μ) (1KH _z ), the saturation magnetization Ms (emu / g) and the saturation magnetization strain λ _S (× 10 ⁻⁶ ) were measured under a frequency of 1 KH _z and a maximum excitation field of 5 mOe. Table 1 shows the composition of the alloy samples, the content of fine crystal grains in the alloy and the average particle diameter.

TABLE 1

As shown in Table 1, the content of fine crystal grains is more than 60% in all samples. The composition of the alloy was determined by IPC analysis.

Magnetic properties are shown in Table 2.

As a comparative example, a gold cold alloy (comparative example, commercially available product) of Fe ₇₈ Si ₉ B ₁₃ was prepared under the same conditions as in Example 1, and the iron loss, permeability, saturation magnetization, and saturation magnetization of these samples are shown in Table 2 below.

TABLE 2

As apparent from the results of Table 2, the iron loss and permeability of the alloy samples of the present invention is almost the same as the comparative example, the alloy of the present invention was found to be sufficiently practical as a magnetic material to replace the Fe-B-based amorphous soft magnetic alloy lost.

FIG. 1 shows an X-ray diffraction curve when the quenched alloy of Fe ₈₈ Zr ₉ P ₂ Cu ₁ (atomic%) (Example 3) formed by the single roll method was heat-treated in an argon atmosphere at 620 ° C. for 1 hour. As is apparent from the figure, the structure of the alloy obtained by heat treatment mainly has a bcc structure.

As is apparent from the results of the above-described examples, the Fe-based soft magnetic alloy of the present invention is characterized by low iron loss, high permeability and low saturation by adding Cu to specific Fe (P) -based alloys, in particular Zr. Excellent magnetic properties such as deformation. Therefore, the alloy of the present invention can be widely used as a magnetic material to replace the Fe-B-based soft magnetic alloy such as a magnetic head, a high frequency transformer, a saturation functional reactor, a choke coil, and the like.

In addition, since the Fe-based soft magnetic alloy of the present invention uses phosphorus (P) instead of boron (B), the production cost of the alloy can be reduced.

Claims (12)

Fe-based soft magnetic alloy Fe _100-abcd P _a M _b M ' _c Cu _d characterized by having a composition as shown in the formula M is Zr, Hf, Nb, Mo, W, Ta, Ti, V, At least one element selected from the group consisting of Cr, Mn, Y and Ce, and M 'is at least one element selected from the group consisting of Si, Al, Ga, Ge, Ru, Co, Ni, Sn, Sb and Pd , a, b, c and d are each atomic% and satisfy 0a≤25, 0b≤15, 0≤c≤20 and 0≤d≤5, respectively. 2. The Fe-based soft magnetic alloy of claim 1, wherein at least 30% of the alloy structure is made of fine crystal grains. 3. The Fe-based soft magnetic alloy of claim 2, wherein the crystal grain is a bcc solid solution mainly composed of iron. The Fe-based soft magnetic alloy according to claim 2 or 3, wherein the average grain size of the crystal grains is 100 nm or less. The Fe-based soft magnetic alloy according to claim 1, wherein the saturation magnetostriction (λ _S ) of the alloy is in the range of + 10 × 10 ⁻⁶ to −5 × 10 ⁻⁶ . A quenching alloy having a composition represented by the following formula is prepared by a method selected from a liquid quenching method, a thin film forming method, and a powder forming method, and the quenching alloy is heat-treated. Fe _100-abcd P _a M _b M ' _c Cu _d Wherein M is at least one element selected from the group consisting of Zr, Hf, Nb, Mo, W, Ta, Ti, V, Cr, Mn, Y and Ce, and M 'is Si, Al, Ga, Ge, Ru At least one element selected from the group consisting of Co, Ni, Sn, Sb and Pd, a, b, c and d are each atomic% and are 0a≤25, 0b≤15, 0≤c≤20, 0≤ d≤5 is satisfied. The method for producing a Fe-based soft magnetic alloy according to claim 6, wherein the heat treatment of the quenched alloy is maintained at a temperature of 350 to 700 ° C for 24 hours or less. 7. The method of producing a Fe-based soft magnetic alloy according to claim 6, wherein the alloy of claim 1 is prepared. The method of producing a Fe-based soft magnetic alloy according to claim 6, wherein the alloy of claim 2 is prepared. The method of producing a Fe-based soft magnetic alloy according to claim 6, wherein the alloy of claim 3 is prepared. The method for producing an Fe-based soft magnetic alloy according to claim 6, wherein the alloy according to claim 4 is prepared. The method for producing an Fe-based soft magnetic alloy according to claim 6, wherein the alloy according to claim 7 is prepared.