JPH0578794A - Thin strip and powder of hyperfine-grained alloy and magnetic core using the same - Google Patents

Abstract

PURPOSE:To provide a thin strip and powder of an alloy having excellent soft magnetic characteristics and suitable for use in a transformer, a choke coil, etc. CONSTITUTION:A thin strip or powder of a hyperfine-grained alloy having a compsn. represented by a formula L100-x-yMxCy (atomic %) (where L is at least one kind of element selected among Fe, Co and Ni, M is at least one kind of element selected among Ti, Zr, Hf, V, Nb, Mo, Ta, Cr, W and Mn, 2<=x<=20, 5<=y<=25 and 7<=x+y<=35) is obtd. At least 50% of the structure of the alloy is composed of grains of <=500Angstrom grain size and part of the grains contain a C compd.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to an ultrafine crystal having excellent magnetic properties, excellent stability of magnetic properties, a high hardness, and a structure most suitable for a magnetic core component or the like having ultrafine crystal grains. The present invention relates to an alloy ribbon and powder, and a magnetic core using the same.

[0002]

2. Description of the Related Art Conventionally, as a magnetic core material used for magnetic parts, a magnetic core made of ultra-thin silicon steel, Fe-based and Co-based amorphous alloy ribbon, ferrite or the like has been mainly used. Ferrite cores are used especially in the high frequency region of 100 kHz or higher because of low core loss at high frequencies.
However, the saturation magnetic flux density is low, and there is a problem that the magnetic core becomes large in the case of an application such as a magnetic switch in which the operating magnetic flux density must be increased. On the other hand, the silicon steel magnetic core has a high saturation magnetic flux density, but has a problem that the magnetic characteristics at high frequencies are poor. In recent years, amorphous alloys and Fe-based microcrystalline materials described in Japanese Patent Application Laid-Open No. 1-110707 have been developed and used for various magnetic parts such as high frequency transformers, choke coils and magnetic switches due to their excellent high frequency magnetic characteristics.

[0003]

Recently, Fe-based amorphous alloys having a high saturation magnetic flux density and relatively excellent high-frequency characteristics have been used for these applications. However, the Fe-based amorphous alloy has remarkably large magnetostriction, and the soft magnetic characteristics are superior to those of silicon steel, especially in the high frequency region, but they are not sufficient.

Co-based amorphous alloys are excellent in soft magnetic characteristics and have a small magnetostriction, and therefore are suitable in terms of characteristics. However, especially when the operating temperature rises, magnetic permeability, magnetic core loss and the like change with time and there is a problem in practical use. ..

Japanese Unexamined Patent Publication (Kokai) No. 1-110707 describes that Fe-based microcrystalline alloy exhibits excellent high frequency characteristics. However, these alloys do not have sufficient frequency characteristics in the frequency range exceeding 100 kHz, and further improvement in characteristics is desired.

[0006] Recently, Fe-MC (M = Ti, Zr, Hf) films exhibiting high saturation magnetic flux density and high magnetic permeability have been reported in Technical Report MR89-12,
It is reported in p9 etc. However, since this is a thin film formed by sputtering or the like, there are restrictions in shape, and since it is formed on a substrate, it is not suitable for applications such as transformers and choke coils.

Therefore, an object of the present invention is to provide an alloy ribbon and powder which have excellent soft magnetic properties and are suitable for applications such as transformers and choke coils.

[0008]

[Means for Solving the Problems] As a result of earnest research in view of the above problems, the inventors of the present invention have confirmed that an alloy having a compositional formula of L, M, and C as a basic component was prepared by a liquid quenching method (L Is Fe, Co, N
At least one element selected from i, M: Ti, Zr, Hf, V, Nb,
Mo, Ta, Cr, W, at least one element selected from Mn), and at least 50% of the structure consists of crystal grains having a grain size of 500 angstroms or less, and an alloy containing a C compound in a part of the crystal grains The present invention has been newly found out that ribbons and powders exhibit excellent soft magnetic characteristics and are optimal as magnetic core materials for transformers, choke coils, etc., and have conceived the present invention.

That is, the present invention has a composition formula: L _100-xy M _x C
_{Represented by y} (atomic%), L is at least one element selected from Fe, Co, Ni, M is Ti, Zr, Hf, V, Nb, Mo, Ta, Cr, W, Mn
At least one element selected from, 2 ≤ x ≤ 20,5
≤ y ≤ 25, 7 ≤ x + y ≤ 35 alloy having a composition of the relationship, and at least 50% of the structure is composed of crystal grains having a grain size of 500 angstroms or less, and C in a part of the crystal grains It is an ultrafine crystal alloy ribbon or powder characterized by containing a compound.

In the present invention, L is at least one element selected from Fe, Co and Ni and is a ferromagnetic element.

C is an essential element and is effective in making crystal grains fine. M is an essential element, Ti, Zr, Hf, V, Nb, Mo, T
It is at least one element selected from a, Cr, W, and Mn. M
Has an effect of refining crystal grains by the combined addition of C.

The amount of M x, the amount of C y, and the sum x + y of M and C are each 2
≦ x ≦ 20,5 ≦ y ≦ 25,7 ≦ x + y ≦ 35 is limited to the lower limit, the soft magnetic properties deteriorate, and if the upper limit is exceeded, the saturation magnetic flux density decreases and the soft magnetic properties deteriorate. Because it happens.
Particularly preferred range is 5 ≦ x ≦ 15, 5 ≦ y ≦ 20, 10 ≦ x + y ≦ 30
Is. In this range, particularly excellent soft magnetism can be obtained.

C compound refers to M ₂ C, MC, etc.
That is, it depends on the element selected from M.

Compositional formula: L _100-xy-z M _x C _y X _z (atom
%, Where L is at least one element selected from Fe, Co and Ni, and M is Ti, Zr, Hf, V, Nb, Mo, Ta, Cr, W and Mn at least 1 Ge element, X is at least one element selected from the group consisting of Ge, P, Ga, Al, N, 2 ≤ x ≤ 2
An alloy having a composition of 0,5 ≦ y ≦ 25,0 <z ≦ 20,7 <x + y + z ≦ 35, and at least 50% of the structure has a grain size of 500
Ultrafine crystalline alloy ribbons or powders, which are characterized by having crystal grains of angstroms or less and containing a C compound in a part of the crystal grains, also show excellent soft magnetic properties. X is effective in adjusting magnetostriction and improving soft magnetic characteristics. X amount Z is 20
Must be at% or less. The reason is that when Z exceeds 20 at%, the saturation magnetic flux density is remarkably lowered.

The sum x + y + z of M, C and X is greater than 7 at% and 35 at
Must be less than or equal to%. The reason for this is that if the lower limit is exceeded, the soft magnetic properties will deteriorate, and if the upper limit is exceeded, the saturation magnetic flux density will decrease significantly.

The C compound refers to M ₂ C, MC and the like as described above, and varies depending on the composition system. Also, the composition formula: L _100-xya M _x C _y N _a
(Atomic%), where L is at least one element selected from Fe, Co and Ni, M is selected from Ti, Zr, Hf, V, Nb, Mo, Ta, Cr, W and Mn At least one element, N is Cu, Ag, Au, platinum group elements, Sn, Be, Mg, Ca, Sr, at least one element selected from the group consisting of Ba, 2 ≤ x ≤ 20,5 ≤ y ≤ 25,0 <a ≤ 10,7
An alloy having a composition of <5x + y + a ≦ 35, wherein at least 50% of the structure is composed of crystal grains having a grain size of 500 angstroms or less, and a C compound is contained in a part of the crystal grains. The ultrafine crystal alloy ribbon or powder characterized by the above also exhibits excellent soft magnetic properties.

N has the effect of improving magnetic properties and corrosion resistance. In particular, Cu and Au have the effect of helping to reduce the grain size.

The N content a must be 10 at% or less. The reason is that if it deviates from this range, the saturation magnetic flux density is remarkably lowered.

The total amount of M, C, N x + y + a exceeds 7 at% and 35 at%
Must be: This is because if the value goes below the lower limit, the soft magnetic properties will deteriorate, and if it goes beyond the upper limit, the saturation magnetic flux density will significantly decrease.

The C compound is the same as described above and refers to M ₂ C, MC and the like, which varies depending on the composition system. Also, the composition formula: L
_100-xy-za M _x C _y X _z N _a (atomic%), where L is F
At least one element selected from e, Co, Ni, M is Ti, Zr, H
f, V, Nb, Mo, Ta, Cr, W, at least one element selected from Mn, X is at least one element selected from the group consisting of Ge, P, Ga, Al, N, Si, N Is Cu, Ag, Au, platinum group element, Sn, Be, Mg, C
a, Sr, at least one element selected from the group consisting of Ba, 2 ≦ x ≦ 20,5 ≦ y ≦ 25,0 <z ≦ 20,0 <a ≦ 10,7 <x + y
An alloy having a composition of the relation of + z + a ≦ 35, wherein at least 50% of the structure is composed of crystal grains having a grain size of 500 angstroms or less, and part of the crystal grains contains a C compound. The ultrafine crystalline alloy ribbons and powders also exhibit excellent soft magnetic properties.

X is effective in adjusting magnetostriction and improving soft magnetic characteristics. The X amount Z must be 20 at% or less. The reason is that when Z exceeds 20 at%, the saturation magnetic flux density is remarkably lowered.

N has the effect of improving magnetic properties and corrosion resistance. In particular, Cu and Au have the effect of helping to reduce the grain size. The N content a must be 10 at% or less. The reason is that if it deviates from this range, the saturation magnetic flux density is remarkably lowered.

The total amount of M, C, X and N, x + y + z + a, exceeds 7 at% and is 3
Must be 5 at% or less. This is because if the value goes below the lower limit, the soft magnetic properties will deteriorate, and if it goes beyond the upper limit, the saturation magnetic flux density will significantly decrease.

The C compound refers to M ₂ C, MC and the like as described above, and varies depending on the composition system. In the present invention, M and C form an ultrafine and uniformly dispersed C compound by heat treatment, and have the effect of suppressing the growth of crystal grains. Therefore, it is considered that the magnetocrystalline anisotropy of the crystal grains of the main phase apparently cancels each other to obtain excellent soft magnetic characteristics.

The alloy ribbons and powders of the present invention are usually produced by once preparing amorphous alloy ribbons and powders by a liquid quenching method such as a single roll method, a twin roll method and an atomizing method. It is crystallized and manufactured by heat treatment in a vacuum or in an inert gas atmosphere. However, it is also possible to directly obtain an alloy ribbon or powder having a fine crystal structure by controlling the cooling rate during the liquid quenching.

The alloy ribbons and powders of the present invention may partially retain an amorphous phase depending on heat treatment conditions, but even if they are 100% crystalline, they exhibit sufficiently excellent soft magnetic properties.

The alloy ribbon and powder of the present invention have a remarkably fine grain structure of 500 angstroms or less, and particularly excellent soft magnetism is obtained when the particle size is 200 angstroms or less.

The alloy ribbon and powder of the present invention can also be manufactured by heat treatment in a magnetic field. When a magnetic field is applied in a fixed direction, uniaxial induced magnetic anisotropy can be generated. Further, soft magnetic characteristics can be further improved by performing heat treatment in a rotating magnetic field. It is also possible to perform heat treatment in a magnetic field after the crystallization heat treatment.

The magnetic core of the present invention has a structure in which the alloy ribbons are laminated or wound in a toroidal shape, or a structure in which powder is compression molded.

When an alloy ribbon is used, it is usually crystallized by heat treatment after being laminated or wound in an amorphous state.
At this time, if necessary, an insulating layer is provided on the surface of the ribbon to perform interlayer insulation. As the insulating layer, a film of an oxide such as MgO, Al ₂ O ₃ or SiO ₂ or a nitride such as BN or Si ₃ N ₄ is formed or powder is applied to the surface.

When a powder is used, an amorphous powder usually produced by an ultra-quenching method is mixed with a binder such as water glass, compression-molded by a press, and further heat-treated to crystallize a powder magnetic core or a bulk by a hot press. After this, it is heat treated to manufacture a magnetic core. Moreover, you may make it crystallize by heating at the time of compression molding as needed. Further, it is also possible to manufacture a magnetic core using a ribbon or powder in a microcrystalline state.

[0032]

EXAMPLES The present invention will now be described with reference to examples, but the present invention is not limited thereto.

Example 1 A composition consisting of 8% Mo and 16% C16 with the balance being Fe, width 5 mm, thickness 14
A μm alloy ribbon was prepared by the single roll method. When the obtained ribbon was subjected to X-ray diffraction, a halo pattern peculiar to an amorphous alloy was shown.

Next, this thin strip was wound into a toroidal shape having an outer diameter of 19 mm and an inner diameter of 15 mm, and the core loss at 100 kHz and 0.2 T was measured. A value of 340 kW / m ³ was obtained.

Next, this amorphous alloy ribbon was kept at 650 ° C. for 1 hour in a nitrogen gas atmosphere and then cooled to room temperature, and X
Line diffraction was performed. A crystalline peak of the bcc phase and a Mo-C based compound phase were observed. As a result of observing the structure with a transmission electron microscope, it was confirmed that most of the structure consisted of ultrafine crystal grains with a grain size of 100 angstroms or less.

Example 2 An amorphous alloy ribbon having the composition shown in Table 1 was produced in the same manner as in Example 1 and wound around an outer diameter of 19 mm and an inner diameter of 15 mm to produce a toroidal magnetic core. Next, this magnetic core was heat-treated to crystallize the alloy. The core loss Pc was measured at 100 kHz and 0.2T. The results obtained are shown in Table 1. All the alloys after the heat treatment had a fine grain structure with a grain size of 500 Å or less. It can be seen that the alloy core of the present invention has a low core loss and is excellent.

[0037]

[Table 1] Example 3 Amorphous alloy powder having the composition shown in Table 2 was produced by the gas atomizing method. The alloy powder is then warm pressed to 55
While being crystallized at 0 ° C to 700 ° C, compression molding was performed to prepare a dust core having an outer diameter of 25 mm, an inner diameter of 20 mm and a height of 5 mm.

Thereafter, heat treatment was performed at 550 ° C. As a result of X-ray diffraction and transmission electron microscope observation of the alloy after heat treatment, it was confirmed that the alloy consisted of crystal grains with a grain size of 500 angstroms or less and partially contained the C compound.

Next, the magnetic permeability μ of this magnetic core at 10 MHz was measured. The alloy powder magnetic core of the present invention has μ of 100 or more, which shows excellent high frequency characteristics.

[0040]

[Table 2] Example 4 An alloy ribbon having a composition shown in Table 3 and having a width of 5 mm and a thickness of 16 μm was produced by a single roll method. Next, this magnetic core was heat-treated to crystallize the alloy, and the Vickers hardness was measured. The results obtained are shown in Table 3.

The hardness of the alloy ribbon of the present invention is very high and exhibits excellent characteristics. Therefore, it has excellent wear resistance and the like, and is suitable for a magnetic head magnetic core material and the like.

[Table 3]

[0042]

According to the present invention, it is possible to provide an ultrafine crystal alloy having a low magnetic core loss, a high magnetic permeability and a high hardness, and a method for producing the same, and the effect is remarkable.

Front page continuation (51) Int.Cl. ⁵ Identification code Office reference number FI Technical display location C22C 1/10 E 8928-4K 19/00 H 8928-4K 19/03 D 8928-4K 19/07 C 8928- 4K 38/38 H01F 1/153

Claims (13)

[Claims] 1. A composition formula: L _100-xy M _x C _y (atomic%), wherein L is at least one element selected from Fe, Co and Ni, and M is Ti, Zr, Hf, V, Nb, Mo, Ta, Cr, W, is at least one element selected from Mn, 2 ≦ x ≦ 20,5 ≦ y ≦ 25,7 ≦ x + y ≦ 3
An alloy having a composition of the relationship of 5, and at least 50% of the structure consists of crystal grains having a grain size of 500 angstroms or less, and ultrafine crystals characterized by containing a C compound in a part of the crystal grains. Alloy ribbon. 2. A composition formula: L _100-xy M _x C _y (atomic%), wherein L is at least one element selected from Fe, Co and Ni, and M is Ti, Zr, Hf, V, Nb, Mo, Ta, Cr, W, is at least one element selected from Mn, 2 ≦ x ≦ 20,5 ≦ y ≦ 25,7 ≦ x + y ≦ 3
An alloy having a composition of the relationship of 5, and at least 50% of the structure consists of crystal grains having a grain size of 500 angstroms or less, and ultrafine crystals characterized by containing a C compound in a part of the crystal grains. Alloy powder. 3. A composition formula: L _100-xy-z M _x C _y X _z (atomic%), wherein L is at least one element selected from Fe, Co and Ni, M is Ti, Zr, Hf, V, Nb, Mo, Ta, Cr, W, Mn at least one element, X is at least one element selected from the group consisting of Ge, P, Ga, Al, N , 2 ≦ x ≦ 20, 5 ≦ y
An alloy having a composition of ≦ 25,0 <z ≦ 20,7 <x + y + z ≦ 35, wherein at least 50% of the structure is composed of crystal grains having a grain size of 500 angstroms or less, and said crystal An ultrafine-crystalline alloy ribbon characterized by containing a C compound in a part of a grain. 4. A composition formula: L _100-xy-z M _x C _y X _z (atomic%), wherein L is at least one element selected from Fe, Co and Ni, and M is Ti, Zr, Hf, V, Nb, Mo, Ta, Cr, W, Mn at least one element, X is at least one element selected from the group consisting of Ge, P, Ga, Al, N , 2 ≦ x ≦ 20, 5 ≦ y
An alloy having a composition of ≦ 25,0 <z ≦ 20,7 <x + y + z ≦ 35, wherein at least 50% of the structure is composed of crystal grains having a grain size of 500 angstroms or less, and said crystal An ultra-fine crystal alloy powder characterized by containing a C compound in a part of the grain. 5. A composition formula: L _100-xya M _x C _y N _a (atomic%), wherein L is at least one element selected from Fe, Co and Ni, and M is Ti, Zr, At least one element selected from Hf, V, Nb, Mo, Ta, Cr, W, Mn, N is Cu, Ag, Au, platinum group element, Sn, Be, M
g, Ca, Sr, at least one element selected from the group consisting of Ba, 2 ≦ x ≦ 20,5 ≦ y ≦ 25,0 <a ≦ 10,7 <x + y + a ≦ 35
An alloy having a composition of the relationship of, and at least 50% of the structure is composed of crystal grains having a grain size of 500 angstroms or less, and an ultrafine crystal alloy characterized by containing a C compound in a part of the crystal grains. Thin strip. 6. A composition formula: L _100-xya M _x C _y N _a (atomic%), wherein L is at least one element selected from Fe, Co and Ni, and M is Ti, Zr, At least one element selected from Hf, V, Nb, Mo, Ta, Cr, W, Mn, N is Cu, Ag, Au, platinum group element, Sn, Be, M
g, Ca, Sr, at least one element selected from the group consisting of Ba, 2 ≦ x ≦ 20,5 ≦ y ≦ 25,0 <a ≦ 10,7 <x + y + a ≦ 35
An alloy having a composition of the relationship of, and at least 50% of the structure is composed of crystal grains having a grain size of 500 angstroms or less, and an ultrafine crystal alloy characterized by containing a C compound in a part of the crystal grains. Powder. 7. The composition formula: L _100-xy-za M _x C _y X _z N _a (atom
%, Where L is at least one element selected from Fe, Co and Ni, and M is Ti, Zr, Hf, V, Nb, Mo, Ta, Cr, W and Mn at least 1 Element, X is at least one element selected from the group consisting of Ge, P, Ga, Al, N, Si, N is Cu, Ag, A
u, platinum group element, Sn, Be, Mg, Ca, Sr, at least one element selected from the group consisting of Ba, 2 ≦ x ≦ 20,5 ≦ y ≦ 25,0
<Z ≦ 20,0 <a ≦ 10,7 <x + y + z + a ≦ 35, an alloy having a composition in the relation of at least 50% of the structure consisting of crystal grains having a grain size of 500 angstroms or less. An ultrafine crystalline alloy ribbon characterized by containing a C compound in a part of the crystal grains. 8. The composition formula: L _100-xy-za M _x C _y X _z N _a (atom
%, Where L is at least one element selected from Fe, Co and Ni, and M is Ti, Zr, Hf, V, Nb, Mo, Ta, Cr, W and Mn at least 1 Element, X is at least one element selected from the group consisting of Ge, P, Ga, Al, N, Si, N is Cu, Ag, A
u, platinum group element, Sn, Be, Mg, Ca, Sr, at least one element selected from the group consisting of Ba, 2 ≦ x ≦ 20,5 ≦ y ≦ 25,0
<Z ≦ 20,0 <a ≦ 10,7 <x + y + z + a ≦ 35, an alloy having a composition in the relation of at least 50% of the structure consisting of crystal grains having a grain size of 500 angstroms or less. An ultrafine crystal alloy powder characterized by containing a C compound in a part of the crystal grains. 9. The microcrystalline alloy ribbon or powder according to claim 1, wherein the rest of the texture is amorphous. 10. The method according to claim 1, which consists essentially of a crystalline phase.
9. The ultrafine crystal alloy ribbon or powder according to any one of 1 to 8. 11. The ultrafine crystal alloy ribbon or powder according to claim 1, wherein the grain size of the crystal grains is 200 angstroms or less. 12. A magnetic core having a structure in which the ultrafine crystal alloy ribbon according to any one of claims 1, 3, 5, or 7 is laminated or wound in a toroidal shape. 13. A magnetic core having a structure obtained by compression-molding the ultrafine crystal alloy powder according to any one of claims 2, 4, 6, or 8.