JPH0559408A - Production of soft magnetic powder - Google Patents

Abstract

PURPOSE:To mass-produce a soft magnetic powder contg. a metastable (Fe, M)16N2 phase (where M is one or >=2 kinds among Ti, Zr, Hf, V, Nb and Ta) and having high Bs and low Hc. CONSTITUTION:An Fe-N-based alloy powder consisting essentially of an epsilon-FeXN phase (X=2 or 3) is mixed with >=2 kinds among pure Fe powder, Fe-M-based alloy powder and pure M powder so that the composition of the mixture is controlled to (Fe1-alphaMalpha)1-betaNbeta (where alpha=0.02 to 0.15 and beta=0.05 to 0.15), and the obtained powder is mixed and crushed while being imparted with high energy. A soft magnetic powder having a metastable (Fe, M)16N2 phase is produced in this way.

Description

Detailed Description of the Invention

[0001]

This invention has a high saturation magnetic flux density (hereinafter referred to as Bs) and a coercive force (hereinafter referred to as Hc).
And a method for producing a soft magnetic powder having a small size.

[0002]

2. Description of the Related Art Conventionally, magnetic cores of motors and transformers,
Furthermore, resin-bonded soft magnetic composite members such as magnetic shields,
A soft magnetic powder such as pure Fe powder is mixed with a resin binder such as an epoxy resin in a predetermined ratio, mixed, and then pressure-molded into a green compact having a predetermined shape, and the green compact is subjected to a resin curing treatment. It is well known that it is manufactured by

Since the pure Fe powder does not have a sufficiently large Bs, a soft magnetic powder mainly composed of a metastable Fe ₁₆ N ₂ phase having a Bs higher than that of the pure Fe powder has recently been attracting attention. ..

[0004]

However, the soft magnetic powder containing the metastable Fe ₁₆ N ₂ phase as the main structure is N ₂
The thin film formed by vapor deposition or sputtering in gas is peeled off and cannot be mass-produced because it is manufactured by crushing,
The soft magnetic powder mainly composed of the metastable Fe ₁₆ N ₂ phase produced in this manner has a high Bs but a high Hc. Therefore, a dust core produced using this soft magnetic powder is also used. Hc becomes large, and it has not been possible to satisfy the high efficiency and energy saving of various electric and electronic devices incorporating the same.

[0005]

Therefore, the present inventors have
As a result of research to solve such problems, ε-Fe _X
Fe—N alloy powder mainly composed of N (X = 2 to 3) phase was used as an essential compounding powder, and other pure Fe powder and M powder (where M is Ti, Zr, Hf, V, Nb, Ta) are used. (1 or more of them) and Fe-M alloy powder are mixed and pulverized and mixed while giving high energy, and the metastable Fe ₁₆ N ₂ phase (hereinafter,
A powder having a main structure of (Fe, M) ₁₆ N ₂ phase) was obtained, and this powder was metastable (Fe,
Since the crystal grains of the M) ₁₆ N ₂ phase are fine, it has been found that Hc can be significantly reduced without substantially reducing Bs.

[0006] This invention was made based on such finding, the Fe-N based alloy powder mainly comprising _{ε-Fe X N (X =} 2~3) phase as essential compounding powder, other net Fe powder, Fe-M alloy powder and pure M powder are blended to produce a blended powder, and the blended powder is crushed and mixed while giving high energy. (Fe, M) ₁₆ N ₂ soft magnetic powder having a phase It is characterized by the manufacturing method of.

The above compounded powder has a total composition of (Fe _1-α ,
M _α ) _1-β N _β (where α = 0.02 to 0.15, β =
It is preferable to mix it so as to be 0.05 to 0.15). When α is less than 0.02, Hc cannot be lowered because the Fe ₁₆ N ₂ phase crystal grains due to M cannot be made finer. On the other hand, when α is more than 0.15, Fe is reduced.
_This is because the decrease in Bs of the ₁₆ N ₂ phase is large and is not preferable, and even if β is less than 0.05 or more than 0.15, formation of a metastable (Fe, M) ₁₆ N ₂ phase is formed. This is because it is difficult and not preferable.

The pure Fe powder, the Fe-M type alloy powder and the pure M powder used in the method for producing the soft magnetic powder of the present invention are all commercially available, but ε-Fe _X N (X =
2-3) Fe-N alloy powder mainly composed of phase is pure Fe.
It is produced by nitriding the powder in an ammonia atmosphere.

Further, as a concrete means for mixing and pulverizing while giving high energy employed in the present invention, a mixing and pulverizing machine such as an attritor mill or a planetary ball mill is used, and the number of balls is increased as compared with a usual mixing and pulverizing operation. High energy is given by increasing the number of rotations, and the mixture is ground.

[0010]

[Examples] Atomized pure Fe powder, pure Ti powder, and pure Zr having a particle size of -100 mesh as the raw material powder
Powder, pure Hf powder, pure V powder, pure Nb powder, pure Ta powder, and Fe-M alloy powder having a predetermined composition are prepared respectively, and the atomized pure Fe powder of -100 mesh is further heated in an ammonia atmosphere at a temperature of: 580 ° C., and nitrided under the conditions of 130 hour _{hold, ε-Fe X N (X} = 2~3) FeN -based alloy powder having a composition of Fe-28 atomic% N mainly tissue (hereinafter, FeN powder Was produced, and this FeN powder was also prepared as a raw material powder.

These raw material powders were blended so that the overall composition would be the blending composition (molar ratio) shown in Tables 1 to 7, and the resulting blended powders were made of stainless steel balls 11 having a diameter of 11 mm.
Along with the above, the above-mentioned container of a planetary ball mill equipped with a stainless steel container having a volume of 80 cm ³ is charged, and the container is made an N ₂ atmosphere, and subjected to high energy treatment by rotating for 20 hours at a container revolution speed of 300 rpm. Invention Method 1-62
And Comparative methods 1 to 15 were carried out. The above comparison methods 1 to 15
Is that the value of α or β is out of the condition of the present invention,
These outlying values are marked with *.

[0012]

[Table 1]

[0013]

[Table 2]

[0014]

[Table 3]

[0015]

[Table 4]

[0016]

[Table 5]

[0017]

[Table 6]

[0018]

[Table 7]

The methods 1 to 62 of the present invention and the comparative methods 1 to 1
By carrying out step 5, the soft magnetic powder thus obtained was subjected to selected area electron beam diffraction using a 200 KV transmission electron microscope to determine the metastable (Fe, M) ₁₆ N ₂ phase production rate (volume%). The metastable (Fe,
M) ₁₆ N ₂ phase reflection was used to form a dark field image, and a photograph was taken. From this photograph, the volume fraction of the metastable (Fe, M) ₁₆ N ₂ phase was calculated. The saturation magnetic flux density Bs of the obtained soft magnetic powder was measured using a vibrating sample magnetometer by applying a magnetic field of 10 kOe, and the coercive force H
For c as well, a vibrating sample magnetometer was used and measurement was performed by applying a magnetic field of 100 Oe. The obtained metastable (Fe, M)
The measurement results of ₁₆ N ₂ phase production rate, Bs and Hc are shown in Table 8 to
It is shown in Table 13.

[0020]

[Table 8]

[0021]

[Table 9]

[0022]

[Table 10]

[0023]

[Table 11]

[0024]

[Table 12]

[0025]

[Table 13]

[0026]

From the results shown in Tables 1 to 13, pure F
e powder, pure M powder, Fe-M powder and FeN powder,
The overall composition is (Fe _1-α , M _α ) _1-β N _β (where α =
0.02 to 0.15, β = 0.05 to 0.15), and the resulting blended powder is subjected to high energy treatment so that Bs is not lowered so much that Hc
It turns out that can be lowered.

Therefore, according to the present invention, the metastable (F
e, M) It is possible to mass-produce soft magnetic powder with low Hc containing ₁₆ N ₂ phase, and use this soft magnetic powder to produce highly efficient and low energy consumption resin-bonded powder electromagnetic components at low cost. , Can greatly contribute to the development of industry.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Office reference number FI technical display location C22C 33/04 D 8414-4K

Claims (5)

[Claims] 1. Pure Fe powder, pure M powder (where M is T
1 or 2 of i, Zr, Hf, V, Nb, Ta
Or more), and Fe—N alloy powder mainly composed of ε-Fe _X N (X = 2 to 3) phase, and compounded powder obtained by mixing and pulverizing while giving high energy. And the metastable Fe ₁₆ N ₂ phase (hereinafter,
A method for producing a soft magnetic powder having a (Fe, M) ₁₆ N ₂ phase). 2. Pure Fe powder, Fe-M alloy powder, and Fe-N mainly composed of ε-Fe _X N (X = 2 to 3) phase.
A method for producing a soft magnetic powder having a metastable (Fe, M) ₁₆ N ₂ phase, which comprises mixing and pulverizing a compounded powder obtained by mixing a system alloy powder. 3. Fe-M alloy powder and ε-Fe _X N
Metastable (Fe, M) ₁₆ characterized by mixing and pulverizing a compounded powder obtained by compounding Fe—N alloy powder mainly composed of (X = 2-3) phase while giving high energy. N
_A method for producing a soft magnetic powder having _two phases. 4. A blended powder obtained by blending pure M powder, Fe-M alloy powder, and Fe-N alloy powder mainly composed of ε-Fe _X N (X = 2 to 3) phase. A method for producing a soft magnetic powder having a metastable (Fe, M) ₁₆ N ₂ phase, which comprises: 5. The above-mentioned compounded powder is pure Fe powder, pure M powder, Fe-M alloy powder, and ε-Fe _X N (X = 2).
~ 3) Fe-N alloy powder mainly composed of phase is (Fe _1-α , M _α ) _1-β N _β (where α = 0.02-
0.15, β = 0.05 to 0.15), and the metastable (Fe, M) ₁₆ N ₂ phase according to claim 1, 2, 3 or 4. Of a soft magnetic powder having