JP2713714B2 - Fe-based magnetic alloy - Google Patents

Description

The present invention relates to an Fe-based magnetic alloy having excellent magnetic properties and small magnetostriction, and particularly to an Fe-based magnetic alloy in which most of the structure is composed of fine crystal grains. . Conventionally, ferrite, which has advantages such as low eddy current loss, has been mainly used as a magnetic core material for high-frequency transformers, magnetic heads, saturable reactors, choke coils, and the like. However, since ferrite has low saturation magnetic flux density and poor temperature characteristics, it has a drawback that it is difficult to reduce the size of a magnetic core when used in a high-frequency transformer or a choke coil. In recent years, amorphous magnetic alloys having a high saturation magnetic flux density as a countermeasure to conventional magnetic core materials are promising,
Various compositions have been developed. Amorphous alloys are mainly classified into Fe-based and Co-based.Fe-based amorphous alloys have the advantage that the material cost is lower than that of Co-based alloys. There is a problem that the core loss is large and the magnetic permeability is low. On the other hand, the Co-based amorphous alloy has a small high-frequency core loss and a high magnetic permeability, but has a large change with time in the core loss and the magnetic permeability. More expensive
Since Co is the main raw material, price disadvantages are inevitable. Under such circumstances, various proposals have been made for Fe-based amorphous magnetic alloys. JP-B-60-17019 discloses that 74 to 84 atomic% of Fe and 8 to 24
Raw material% B, 16 atomic% or less Si and 3 atomic% or less C
Wherein at least 85% of the structure has the shape of an amorphous metal body and is discontinuously distributed throughout the amorphous metal body. Having a precipitate of the crystalline particle group, the crystalline particle group has an average particle size of 0.05 to 1 μm and an average interparticle distance of 1 to 10 μm, and the particle group has an average of 0.01 to 0.3 of the whole. An iron-based boron-containing magnetic amorphous alloy characterized by occupying a volume fraction is disclosed. The crystalline particles of this alloy have a discontinuous distribution of α that acts as a domain wall pinning point.
-(Fe, Si) particles. The JP 60-52557 is _{Fe a Cu b B c Si d} ( provided that 75 ≦ a
≦ 85, 0 ≦ b ≦ 1.5, 10 ≦ c ≦ 20, d ≦ 10 and c + d ≦ 30). This amorphous magnetic alloy is heat-treated at a temperature lower than the crystallization temperature and higher than the Curie temperature. [Problems to be Solved by the Invention] The Fe-based soft magnetic alloy disclosed in JP-B-60-17019 has a reduced core loss due to the presence of discontinuous crystal grains, but has a large time-dependent change in a high-frequency transformer or choke. It is not satisfactory as a material for magnetic cores. On the other hand, the core loss of the Fe-based amorphous alloy disclosed in JP-A-60-52557 is remarkably reduced due to the inclusion of Cu, but is as satisfactory as the Fe-based amorphous alloy containing crystalline particles. is not. Further, there is a problem that the change with time of the core loss and the magnetic permeability are not sufficient. In addition, the magnetostriction is large, the variation in magnetic properties is large, the Curie temperature is lower than that of an Fe-Si-Al alloy or an Fe-Si alloy, and the stability of magnetic properties is poor. Accordingly, an object of the present invention is to provide a novel Fe-based soft magnetic alloy which has a small magnetostriction and is excellent in core loss, change in core loss with time, magnetic permeability and stability of other magnetic properties. [Means for Solving the Problems] In view of the above objects, as a result of intensive studies, the present inventors have found that the following alloys having any one of the following compositions (a) to (e):
According to the present invention, it has been found that excellent soft magnetism can be obtained when at least 50% of the structure is composed of fine crystal grains and the average of the particle diameters measured at the maximum dimension of the crystal grains is 1000 ° or less. I arrived. (A) A composition comprising 4 to 30 atomic% of Si, 2 to 9 atomic% of B, and the balance Fe. (B) 4 to 30 atomic% of Si, 2 to 9 atomic% of B, 20% of M '
Atomic% or less (M 'is selected from the group consisting of Nb, W, Ta, Zr, Hf, Ti, Mo, V, Cr, Mn, white metal element, Sc, Y, rare earth element, Au, Zn, Sn, Re At least one element), and the balance being Fe. (C) 4 to 30 atomic% of Si, 2 to 9 atomic% of B, 20% of M '
Atomic% or less (M 'is selected from the group consisting of Nb, W, Ta, Zr, Hf, Ti, Mo, V, Cr, Mn, white metal element, Sc, Y, rare earth element, Au, Zn, Sn, Re At least one element), X is not more than 20 atomic% (X
Is at least one selected from the group consisting of C, Ge, Ga, Al, Be
Element) and the balance of Fe. (D) 4 to 30 atomic% of Si, 2 to 9 atomic% of B, 20% of M '
Atomic% or less (M 'is selected from the group consisting of Nb, W, Ta, Zr, Hf, Ti, Mo, V, Cr, Mn, white metal element, Sc, Y, rare earth element, Au, Zn, Sn, Re At least one element), Y is not more than 20 atomic% (Y
Are P, Sb, In, As, Li, Mg, Ca, Sr, Ba, Cd, Pb, Bi, N, O, S, Se and T
e) at least one element selected from the group consisting of e) and the balance of Fe. (E) 4 to 30 atomic% of Si, 2 to 9 atomic% of B, 20% of M '
Atomic% or less (M 'is selected from the group consisting of Nb, W, Ta, Zr, Hf, Ti, Mo, V, Cr, Mn, white metal element, Sc, Y, rare earth element, Au, Zn, Sn, Re At least one element), X is not more than 20 atomic% (X
Is at least one selected from the group consisting of C, Ge, Ga, Al, Be
A composition in which 50 atomic% or less of Fe and the balance of Fe are replaced with Co and / or Ni (however, the substitution amount of Ni is less than 20 atomic%). In the present invention, Si and B are essential elements, and are useful elements for refining the crystal grains of the alloy and improving the soft magnetic properties for adjusting the magnetostriction. The alloy of the present invention is preferably obtained by once forming an amorphous alloy by adding Si and B, and then forming fine crystal grains by heat treatment. The reason for limiting the Si content is that if the content exceeds 30% by raw material, magnetostriction increases under favorable conditions of soft magnetic characteristics, and if it is less than 4 atomic%, the soft magnetic characteristics are significantly deteriorated, which is not preferable. The reason for limiting the content of B is 2
If the content is less than atomic%, it is difficult to obtain a uniform crystal grain structure and the soft magnetic properties deteriorate, which is not preferable. If the content exceeds 9 atomic%, the magnetostriction increases under heat treatment conditions with good soft magnetic properties, which is not preferable. X is at least one element selected from the group consisting of C, Ge, Ga, Al and Be, and these elements are made amorphous, magnetostrictive,
Effective for Curie temperature adjustment. The reason for limiting the content of X is that if it exceeds 20 atomic%, the soft magnetic properties are significantly deteriorated, and the saturation magnetic flux density is reduced. If the total amount of Si, B, and X is less than 10 atomic%, it becomes difficult to amorphize and the magnetic properties deteriorate, and if it exceeds 35 atomic%, the saturation magnetic flux density decreases significantly and There is deterioration of characteristics. More preferable ranges of the Si and B contents are 10 to 25 atomic% of Si and 4 to 7 atomic% of B. In this range, particularly excellent soft magnetism can be obtained, and those having small magnetostriction can be easily obtained. In the alloy according to the present invention, M ′ is Nb, W, Ta, Zr, Hf, Ti, M
o, V, Cr, Mn, at least one element selected from the group consisting of white metal elements, Sc, Y, rare earth elements, Au, Zn, Sn, and Re to refine crystal grains and improve corrosion resistance It has an effect of improving, and can contain up to 20 atomic%. The reason for this is that when the content of M ′ exceeds 20 atomic%, the saturation magnetic flux density significantly decreases. A particularly preferred M 'content is 1 to 10 at%, and excellent soft magnetism can be obtained in this range. In particular, as M ', Nb, W, Ta and Mo
Is preferred in terms of soft magnetic properties. The additive element Y is P, Sb, In, As, Li, Mg, Ca, Sr, Ba, Cd, Pb, Bi,
At least one element selected from the group consisting of N, O, S, Se and Te, and may contain up to 2 atomic%. The balance is substantially Fe-excluding impurities, but Fe
May be substituted by Ni and / or Co. The substitution amount of Ni is less than 20 atomic%. If it exceeds 20 atomic%, the soft magnetism is remarkably deteriorated, and a particularly preferable range is 10 atomic% or less. Particularly good soft magnetism can be obtained in this range. The substitution amount of Co is less than 50 atomic%, and the sum of the contents of Ni and Co is less than 50 atomic%. Particularly preferred Co content is 10 atomic% or less, and the total content of Co and Ni is 10 atomic% or less. The alloy of the present invention is an alloy mainly composed of fine bcc Fe solid solution, and at least 50% of the structure is composed of fine crystal grains, and the average of the particle diameters measured at the maximum dimension of the crystal grains is 1000 ° or less. Alloy. Usually, an amorphous alloy is prepared by a liquid quenching method such as a single roll method or a twin roll method, or a gas phase quenching method such as a sputtering method or a vapor deposition method, and then is heated and crystallized. Particularly, when the average of the particle diameters measured at the largest dimension has an average particle diameter of 500 ° or less, particularly excellent soft magnetic properties can be obtained. The remainder of the crystal grains is mainly amorphous, but the alloy of the present invention can obtain sufficiently excellent soft magnetic properties even if it is substantially 100% crystalline. The present invention alloy is an alloy mainly comprising bcc Fe solid solution, which saturation magnetostriction lambda _S is in the range of -5 × 10 ^-6 ~5 × 10 ^-6 is obtained, is significantly magnetostriction than Fe-base amorphous alloy small. Also, an alloy having almost zero magnetostriction can be obtained. As described above, the Fe-based magnetic alloy of the present invention has a single-roll method,
Heat treatment after forming amorphous ribbon by twin roll method, centrifugal quenching method, etc. to form fine crystal grains, amorphous film by vapor deposition method, sputtering method, ion plating, etc. Amorphous powder is obtained by atomizing or cavitation, then heat-treated and crystallized. Amorphous wire is obtained by spinning in a rotating liquid or glass-coated spinning, then heat-treated and crystallized. It can be produced by various methods such as a method. Therefore, the alloy of the present invention can be formed into various shapes such as powder, wire, ribbon, film, and the like, and a bulk body can be obtained by performing pressure welding or the like. The heat treatment performed to obtain the present alloy is performed for the purpose of reducing the internal strain, improving the soft magnetic characteristics with a fine grain structure, and reducing the magnetostriction. The heat treatment is usually performed in a vacuum or in an inert gas atmosphere such as a hydrogen gas, a nitrogen gas, and an argon gas.
However, in some cases, it may be performed in the atmosphere. The heat treatment temperature and time vary depending on the shape, size, and composition of the magnetic core made of the amorphous alloy ribbon, but are generally 450 ° C to 7 ° C.
Desirably, the temperature is about 5 minutes to 24 hours at 00C. Conditions for temperature rise and cooling during the heat treatment can be arbitrarily changed according to the situation. Further, heat treatment may be performed a plurality of times at the same temperature or different temperatures, or heat treatment may be performed in a multi-step heat treatment pattern. Furthermore, the alloy can be heat-treated in a DC or AC magnetic field.
Magnetic anisotropy can be generated in the present alloy by heat treatment in a magnetic field. When a magnetic field is applied in the direction of the magnetic path of the magnetic core made of this alloy and heat treatment is performed, a BH curve having good squareness can be obtained, and a saturable reactor, a magnetic switch, a pulse compression core, and a spike voltage prevention reactor can be obtained. In the case where heat treatment is performed by applying a magnetic field in a direction perpendicular to the magnetic path, the BH curve is inclined, and a characteristic with a low squareness ratio and excellent magnetic permeability is obtained. And a noise filter, a choke coil and the like. The magnetic field does not need to be applied during the heat treatment, and a temperature lower than the Curie temperature Tc of the alloy is sufficiently effective. The Curie temperature of the main phase of the alloy of the present invention is higher than that of the amorphous alloy, and heat treatment in a magnetic field can be applied even at a temperature higher than the Curie temperature of the amorphous alloy. In addition, soft magnetic characteristics can be further improved by performing heat treatment in a rotating magnetic field. Further, it is also possible to heat-treat the alloy by applying a current to the alloy or applying a high-frequency magnetic field to generate heat in the alloy during the heat treatment. The magnetic properties can also be adjusted by heat treatment under stress. In particular, since the alloy of the present invention has a characteristic of low magnetostriction, even if an insulating layer is formed on the surface of the alloy or impregnation or coating is performed, there is a characteristic that the magnetic characteristic is small, and a mold core and a cut core having excellent characteristics are provided. , Coating core, magnetic head, etc. [Examples] The present invention will be described in more detail with reference to the following examples, but the present invention is not limited thereto. Example 1 An alloy ribbon was produced by a single roll method from a molten metal having a composition consisting of 17.5 at% of Si, 5 at% of B, 3 at% of Nb, and the balance being substantially Fe. The plate thickness was 18 μm and the width was 3 mm. When an X-ray diffraction of this alloy was performed, a halo pattern peculiar to the amorphous alloy was obtained. No crystal phase was observed by observation of the structure with a transmission electron microscope. The crystallization temperature of this alloy was 541 ° C. Next, this alloy was wound in a toroidal shape having an outer diameter of 19 mm and an inner diameter of 15 mm to form a wound core. Next, the core was placed in a furnace in an Ar atmosphere maintained at 530 ° C., maintained for 1 hour, and cooled to room temperature at a cooling rate of 5 ° C./min. FIG. 1A shows an X-ray diffraction pattern, and FIG. 1B shows a schematic diagram of a microstructure observed by a transmission electron microscope. X-ray diffraction and observation of the structure by transmission electron microscopy confirmed that most of the structure of the alloy of the present invention was composed of fine bcc Fe solid solution particles having a particle size of 50 to 500 A. Magnetic properties, core losses W ₂ / 100K saturation magnetic flux density Bs 12.4 kg, the effective permeability in 14300,2KG100KHz at 1KHz
Was 630 mW / cc, and it was confirmed that the composition exhibited excellent soft magnetism. The saturation magnetostriction λ _S was + 2.5 × 10 ⁻⁶ , which was confirmed to be significantly smaller than that of the Fe-based amorphous alloy. Example 2 An alloy ribbon having a thickness of 18 μm and a width of 5 mm was prepared by a single roll method from a molten metal having a composition of 17.8 at% of Si, 5.0 at% of B, 3.1 at% of Nb, and the balance substantially of Fe in atomic%. This alloy showed a halo pattern peculiar to the amorphous alloy as a result of X-ray diffraction. The structure was observed with a transmission electron microscope, and no crystal phase was observed. Thus, the alloy was confirmed to be an amorphous single phase. Next, this alloy ribbon was wound into a toroidal shape having an outer diameter of 19 mm and an inner diameter of 15 mm to form a toroidal magnetic core, and heat-treated in a nitrogen gas atmosphere. The holding time was 1 hour. Samples during heat treatment
The sample was rotated by applying a magnetic field of 5000 Oe. Cooling is 5 ℃ / m
Performed at a cooling rate of in. Table 1 shows the relationship between the heat treatment temperature and the magnetic properties and the proportion of the crystal phase. The ratio of the crystalline phase exceeds the saturation magnetostriction constant lambda _S is significantly reduced 50%, and soft magnetic characteristics it can be seen that good characteristics. Although effective permeability of 1KHz of an alloy of the amorphous state ratio is 0% crystalline phase sometimes slightly lower, a problem no value practically, distortion caused by such impregnation for lambda _S is remarkably small features This is advantageous when it is used for a mold core or the like because the deterioration of the magnetic characteristics due to the above is small. Example 3 An alloy ribbon having a composition shown in Table 2 and having a thickness of 15 μm and a width of 5 mm was produced by a single roll method. Next, the outer diameter of 19mm the alloy ribbon, to prepare a winding toroidal core to the inner diameter 15 mm, after heat treatment at the crystallization temperature or higher in an N ₂ gas atmosphere 100 KHz, the core loss in the 0.2T, saturation magnetostriction lambda _S 120 ° C. Was measured for the increase rate of the core loss after holding for 1000 hours. Table 2 shows the obtained results. W ₀ : Initial core loss W ₁₀₀₀ : Core loss after 1000 hours In addition, as a result of observation of the structure by a transmission electron microscope, it was confirmed that the microstructure was almost the same as that in Example 1. The present invention alloy as can be seen from the table saturation magnetostriction lambda _S is significantly smaller than a conventional Fe-based amorphous alloy, less core losses. Further, the rate of change of core loss with time is remarkably small and stable as compared with Fe-based and Co-based amorphous alloys. Therefore, a highly reliable magnetic core can be manufactured. Example 4 An alloy film having a composition shown in Table 3 and having a thickness of 3 μm was formed on a photocell substrate by magnetron sputtering. X
It was confirmed that the alloy film obtained as a result of the line diffraction was substantially an amorphous single phase. Next, this alloy was heated to a temperature higher than the crystallization temperature in a N ₂ gas atmosphere and heat-treated. The structure of the obtained alloy film was almost the same as in Example 1. Then, the effective permeability μe1M of 1MHz of the alloy film was measured and then 120 ° C. 1000 hours after holding of 1MHz effective permeability ▲ μe ¹⁰⁰⁰ _1M ▼ was measured. Table 3 shows the rate of change 実 効 μ _1M of the effective magnetic permeability at 1 MHz. As can be seen from the table, the alloy film of the present invention is superior to the conventional amorphous alloy film in that the change with time is remarkably small. [Effects of the Invention] According to the present invention, an Fe-based magnetic alloy having excellent soft magnetic properties, small magnetostriction, and excellent thermal stability can be obtained, and the effect is remarkable.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 (a) shows an example of an X-ray diffraction pattern of the alloy of the present invention, and FIG. 1 (b) is a schematic view of the structure of the alloy of the present invention observed by a transmission electron microscope. FIG.

Claims (1)

(57) [Claims] It has a composition of 4 to 30 atomic% of Si, 2 to 9 atomic% of B, and the balance of Fe, and at least 50% of the structure is composed of fine crystal grains. An Fe-based magnetic alloy having an average particle size of 1000 mm or less. 2. Si is 4 to 30 atomic%, B is 2 to 9 atomic%, M 'is 20 atomic% or less (M' is Nb, W, Ta, Zr, Hf, Ti, Mo, V, Cr, Mn, a white metal element , Sc, Y, rare earth elements, at least one element selected from the group consisting of Au, Zn, Sn, Re), and the balance of Fe, and at least 50% of the structure is composed of fine crystal grains. An Fe-based magnetic alloy, wherein the average of the particle diameters measured at the maximum size of the crystal grains is 1000 ° or less. 3. Si is 4 to 30 atomic%, B is 2 to 9 atomic%, M 'is 20 atomic% or less (M' is Nb, W, Ta, Zr, Hf, Ti, Mo, V, Cr, Mn, a white metal element , Sc, Y, a rare earth element, at least one element selected from the group consisting of Au, Zn, Sn, and Re), and X is 20 atom% or less (X is
At least one element selected from the group consisting of C, Ge, Ga, Al, and Be) and the balance of Fe, and at least 50% of the structure is made up of fine crystal grains. An Fe-based magnetic alloy, wherein the average of the particle diameters measured in size has an average particle diameter of 1000 mm or less. 4. Si is 4 to 30 atomic%, B is 2 to 9 atomic%, M 'is 20 atomic% or less (M' is Nb, W, Ta, Zr, Hf, Ti, Mo, V, Cr, Mn, a white metal element , Sc, Y, a rare earth element, at least one element selected from the group consisting of Au, Zn, Sn, Re), and Y in an amount of 2 atomic% or less (Y is
P, Sb, In, As, Li, Mg, Ca, Sr, Ba, Cd, Pb, Bi, N, O, S, Se and Te
At least one element selected from the group consisting of
An Fe-based alloy having a composition of Fe, wherein at least 50% of the structure is composed of fine crystal grains, and the average of the particle diameters measured at the maximum dimension of the crystal grains is 1000 ° or less. Magnetic alloy. 5. Si is 4 to 30 atomic%, B is 2 to 9 atomic%, M 'is 20 atomic% or less (M' is Nb, W, Ta, Zr, Hf, Ti, Mo, V, Cr, Mn, a white metal element , Sc, Y, a rare earth element, at least one element selected from the group consisting of Au, Zn, Sn, and Re), and X is 20 atom% or less (X is
At least one element selected from the group consisting of C, Ge, Ga, Al and Be), and the balance of Fe and 50 atomic% or less of Fe to Co and / or
Or Ni (however, the substitution amount of Ni should be less than 20 atomic%)
Wherein at least 50% of the structure is composed of fine crystal grains, and the average of the particle diameters measured at the maximum dimension of the crystal grains has an average particle diameter of 1000 ° or less. Magnetic alloy.