JP3184201B2 - Flat Fe-Ni-based alloy fine powder and method for producing the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to an average particle size of 0.1 to 30 μm and an average thickness of 2 μm or less, preferably an average particle size of 0.1 to 20 μm and an average thickness of 1 μm.
The present invention relates to the following flat Fe-Ni-based alloy fine powder having excellent soft magnetism and a method for producing the same.

[Conventional technology]

In recent years, in the field of magnetic cards related to personal confidentiality represented by bank cards, credit cards, and the like, there has been an increasing need to apply a coating film made of fine powder of a high magnetic permeability material on the card surface layer for the purpose of magnetic shielding. Such application powder is required to be fine powder with high magnetic permeability and to have a flat powder shape. This is not only necessary from the viewpoint of ease of application and surface smoothness of the coating film, but also due to the shearing force at the time of application, the flat fine powder is moved in the flat direction having the lowest demagnetizing coefficient, that is, in the direction of the card base. It is indispensable from the factor that high magnetic permeability in the in-plane longitudinal direction can be obtained by being aligned in parallel.

Various properties of the powder specifically required for this application are:
Average particle size is 0.1-30μm, average thickness is 2μm or less, and powder holding power is 400A in random aggregate state ignoring demagnetizing field
/ m or less, preferably 240 A / m or less. The thickness of the powder is a value obtained by embedding and solidifying the powder in a resin powder while orienting the powder in a flat direction in a magnetic field, and then evaluating the cross section of the embedded sample with a microscope.

As such a powder, it is conceivable to use an Fe-Ni-based alloy which has a high magnetic permeability as a material and is easily plastically deformed and flattened. However, a mass-production method for obtaining the above-mentioned powder characteristics and characteristics in an Fe-Ni-based alloy has not been proposed yet.

In JP-A-63-35701 and JP-A-63-35706, a flaky high permeability made of a highly magnetically permeable pure metal or alloy material having a thickness of 2 μm or less and a ratio of thickness to diameter of 1/10 or less. It has been proposed to produce magnetic metal powder by a wet ball mill method. Specifically, pure iron powder passed through a 44 μm sieve was mixed with 96 powder.
Crushed over time, and passed through a 25 μm sieve 98% to a wall thickness of 1.0
The scaly powder of μm and the Sendust alloy powder that passed through a sieve of 44 μm were crushed for 96 hours, and the sieve of 25 μm was 96%
A scaly powder having a wall thickness of 1.0 to 1.5 μm that passes is obtained.

Although the above-described method can certainly obtain a magnetic material powder having a thickness of 2 μm or less, it requires a long grinding time of 96 hours, and a fine powder having an average particle size of 30 or 20 μm or less is required. The problem is that it is difficult to obtain by powdering. Further, the coercive force of the obtained powder is remarkably deteriorated by crushing strain, and the coercive force Hc is high. In the above pure Fe powder,
43Oe (3440A / m), 9Oe (720A / m) for sendust alloy powder
Have been reported.

In the case of Sendust alloy, JP-A-62-238305 describes:
A method is disclosed in which a powder is formed by water atomization so as to have a crystal grain size of 100 μm or less, and then pulverized by a pulverizer having a high energy density into a single crystal flake powder having a major axis / minor axis ratio of 10 or more. However, since these flaky powders and flat powders have undergone extremely large deformation due to pulverization, they are provided with a high coercive force due to the pulverization strain, and the magnetic shield of the magnetic card, which is the main subject of the present application. It is insufficient as a method for producing powder for use.

As a method of removing grinding strain, JP-A-58-59268 discloses that a flat sendust powder obtained by repeating a grinding and grinding step in multiple stages from an ingot, and adding annealing in a hydrogen atmosphere as necessary. It is mentioned in the book. However, the coercive force of the powder is not specified, and does not give any knowledge on a specific annealing method for improving the coercive force, which is also unsuitable as a powder manufacturing method for magnetic shielding of a magnetic card of the present application. It is enough.

In addition, none of the above-mentioned disclosure examples mentions the saturation magnetostriction constant at all.

Among the Fe-Ni-based alloys, no specific example was found for permalloy-based flat fine powder, and the present inventor disclosed in Japanese Patent Application No. 63-1234.
According to No. 94, average particle size of 10μm or less by water atomization
Fe-Ni alloy powder is mechanically pulverized to an average grain size of 0.1 to 10
A method for obtaining a flat fine powder having a thickness of 1 μm or less was proposed. That is, here, the Fe-Ni-based alloy has a large plastic deformability, is easily spread, and is relatively easy to flatten, but is difficult to pulverize, and reduces the particle size of the initial powder. It was pointed out that this was important from the viewpoint of grinding efficiency.

The proposed method facilitates flat fine powdering of an Fe—Ni alloy, but reducing the particle size of the initial powder is not presently a mass production method from the atomization point of view. In other words, the water atomizing method is the most mass-produced atomizing process, and is a process that can easily reduce the particle size.However, for an average particle size of 10 μm or less, the molten metal must be sprayed with a water pressure of 1000 kgf / cm ² or more. The installation cost of the high-pressure supply pump and the equipment such as piping become enormous, the maintenance is complicated, and the melt beam diameter needs to be reduced to several mmφ. There are problems such as difficulty in obtaining a thickness of 10 μm or less easily, and the method of Japanese Patent Application No. 63-123494 mentioned above is limited in mass productivity when considered in total from raw material powders.

The flat fine powder having an average particle diameter of 0.1 to 30 μm and an average thickness of 2 μm or less, which is the subject of the present application, is severely strained in addition to being a fine powder. Agglomeration of particles, that is, sintering phenomenon occurs, and the flat shape obtained by pulverization is impaired. Therefore, the actual annealing has to be significantly lower than the low temperature at which powder agglomeration does not occur, that is, the annealing temperature of ordinary bulk material around 1100 ° C, and the holding power of flat powder is a large value exceeding 500 A / m I was

[Problems to be solved by the invention]

The present invention has been made in consideration of the above-mentioned problems of the prior art, and has an average grain size of 0.1 to 30 μm and an average thickness of 2 μm.
The present invention provides a flat Fe-Ni-based alloy fine powder having a coercive force Hc of 400 A / m or less and a method for mass-producing the powder.

[Means for solving the problem]

In the present invention, the saturation magnetostriction constant λs
A Fe-Ni alloy raw material having a composition of 15 × 10 ^{−6 or} less is pulverized into an average grain size of 0.1 to 30 μm and an average thickness of 2 μm or less. Fine powder with a coercive force of 400 A / m or less by annealing while maintaining the flat fine powder shape), among which Ni70-83
%, Mo2-6%, Cu3-6%, Mn1-2%, C0.05% or less,
The balance consists of iron and incidental impurities, and a method for producing the same. In particular, B, P, A
Among the element group consisting of s, Sb, Bi, S, Se, and Te, one or two or more elements are added in an amount of 0.1 to 2% to improve grindability.

That is, the present invention has a composition in which the saturation magnetostriction constant λs measured in the bulk material is within ± 15 × 10 ^-6 , and has an average grain size of 0.1.
1-30 μm, average thickness 2 μm or less, coercive force Hc is 400
A / m or less, flat Fe-Ni alloy fine powder characterized by being obtained by subjecting the raw material powder to mechanical pulverization and annealing, of which PC permalloy in the specific component range is used. What is good, and a raw material having a composition whose saturation magnetostriction constant λs measured within the bulk material is within ± 15 × 10 ^-6 is pulverized to have an average particle size of 0.1 to 30 μm,
An average thickness of 2 μm or less, and thereafter, annealing is performed in a non-oxidizing atmosphere while maintaining the above-mentioned flat fine powder state, so that the coercive force Hc of the powder is 400 A / m or less. This is a method for producing flat Fe-Ni diameter alloy fine powder.

In the production method of the present invention, the annealing of the pulverized powder is performed at a high temperature while preventing agglomeration of particles,
It is desirable to carry out the process while moving or moving the fluidized bed.

In addition, B, P, As, Sb, Bi, S,
Of the element group consisting of Se and Te, one or two or more elements are 0.
It is advantageous to use one containing 1 to 2%. In this case, the raw material powder is heated and oxidized under an atmosphere having a suppressed oxygen potential, that is, under a weakly oxidizing atmosphere, particularly before the pulverization. Further, it is effective from the viewpoint of improving the pulverizing efficiency to use an irregularly shaped powder obtained by atomizing a molten alloy as a raw material and to perform pulverization in the presence of a pulverization aid.

[Action]

In the present invention, the average particle size is 0.1 to 30 μm and the average thickness is 2
μm or less, a method for making the coercive force of the powder in a random aggregate state ignoring the demagnetizing field 400 A / m or less,
As an alloy composition, it is necessary to select an Fe-Ni-based alloy such that the saturation magnetostriction constant measured in the bulk material is within ± 15 × 10 ^−6. High-temperature annealing in an oxidizing atmosphere, more specifically, preferably high-temperature annealing while the powder is flowing or moving.

For the flat fine powder of the present application, a pulverizing step is inevitable. There is also a method to produce flat powder directly from molten metal,
In terms of the surface tension of the molten metal, there is a limit to the thickness of the flat powder that is directly produced from the molten metal, up to about 10 μm even if it is thin,
It is necessary to reduce the wall pressure by some processing and to make the particle size fine while flattening. Therefore, the average particle size is 0.1-30
The powder having a thickness of 2 μm or less and an average thickness of 2 μm or less undergoes extremely large deformation, has a large strain, and is in a state in which the original soft magnetism is significantly impaired. That is, the coercive force of the powder in a random aggregate state ignoring the demagnetizing field is at least 500A
The value exceeds / m. In order to reduce the coercive force of fine powder having a large strain in this way, annealing of the powder is indispensable, but in order to reduce the coercive force after annealing to 400 A / m or less, the saturation magnetostriction constant of the material component is ± The present inventors have newly found that it is necessary to be within 15 × 10 ⁻⁶ . In this case, the saturation magnetostriction constant is difficult to measure with the flat powder of the present invention having a thickness of 2 μm or less, and is represented by a value measured with a plate material having a thickness on the order of mm or more.

More specifically, a high-permeability alloy having a composition of a FeNi ₃ ordered lattice generation region and a composition in the vicinity thereof, a so-called PA permalloy,
In addition, the generation of the ordered lattice is suppressed, and Mo, Cr, Cu, Nb, Mn are added to the Fe-Ni diameter so that high magnetic permeability can be realized even by slow cooling.
Multi-system permalloy to which is added, so-called PC permalloy and its category. These PA system to permalloy PC system, the melting bulk material, the saturation magnetostriction constant close to zero or zero, and by magnetic anisotropy constant K ₁ is close to zero, to be high permeability of intellectual However, in the crushed flat fine powder of the subject of the present application, if the composition has a saturated magnetostriction constant within ± 15 × 10 ^-6 , significant residual strain due to crushing is released by subsequent annealing. It was found that the target coercive force Hc was 400 A / m or less.

Next, the reasons for limiting the PC permalloy component recommended by the present application will be described.

Fe-Ni alloys are known to exhibit high magnetic permeability near 80% Ni, and in particular, Mo permalloy containing 4% Mo is widely used. The alloy powder of the present invention is obtained by adding Cu, Mn, and Mo as magnetic improvement elements to the above-described permalloy to significantly increase the magnetic permeability. If the Ni content is less than 70%, no high magnetic permeability is exhibited, and if it exceeds 83%, the saturation magnetization is reduced. Cu, Mn, and Mo are added for the purpose of improving hard magnetic properties. When Cu is less than 3%, the effect of improving the poor magnetic properties, particularly, the effect of lowering the coercive force Hc is small. Also, Cu
Exceeds 6%, the saturation magnetic flux density decreases and the magnetic permeability also decreases. Mo also shows the same effect as Cu. When Mo is less than 2%, the effect of improving soft magnetism, particularly the effect of lowering the coercive force Hc is small, and when Mo exceeds 6%, the saturation magnetic flux density decreases,
And the magnetic permeability also decreases.

When Mn is less than 1%, the maximum magnetic permeability μm is low and 2%
When the value exceeds 1, the coercive force Hc increases, and between 1% and 2% is effective in increasing the maximum magnetic permeability. When C forms a solid solution in the alloy, it lowers the soft magnetism of the alloy. However, the content of up to 0.05% is allowable in the soft magnetic properties of the powder. The balance is iron and incidental impurities, but Si used as a deoxidizer during dissolution is 1%.
%, There is no problem in characteristics.

Fe-Ni wherein the saturation magnetostriction constant λs is within ± 15 × 10 ^-6
B, P, As, Sb, B
0.1% or more of at least one element group consisting of i, S, Se, Te
As described above, it has been found that powder added at 2% or less is effective, and irregularly shaped powder obtained by a water atomizing method is more preferable. B, P, As, Sb, Bi, S, Se and Te are Ni of the main composition.
Since there is almost no solubility in the enriched Fe-Ni system, the added components are M ₃ B, M ₃ P, M ₃ Sb, M ₅ Sb ₂ , MBi, M
_{As a} brittle intermetallic compound phase such as 3S ₂ , MS, M ₃ Se ₂ , MTe, MTe ₂ and a composite phase thereof, it is preferentially crystallized at a crystal grain boundary. Although each compound phase has a high or low melting temperature, it is extremely brittle and makes the crystal grain boundaries brittle, making it easier to be pulverized compared to a normal Fe-Ni-based alloy that does not intentionally add these element groups. . In other words, since the presence of the grain boundary embrittlement phase promotes the division of the grain boundary units in the initial stage of the pulverization, the reduction in the particle size proceeds particularly early, and the pulverization efficiency is improved. In addition, most of the addition of the above element group is spent in the compound phase at the grain boundary and hardly forms a solid solution in the matrix. Therefore, the saturation magnetostriction constant of the matrix composition is basically ±±.
Within 15 × 10 ⁻⁶ , the target coercive force Hc ≦ 400 A / m can be easily achieved.

B, P, As, Sb, consumed in the formation of the grain boundary compound phase
The element group of Bi, S, Se, and Te may be added alone or in combination, but the total amount is preferably 0.1% or more and 2% or less. If it is less than 0.1%, a visible effect of the pulverization efficiency is not recognized as compared with the case where it is not intentionally added. Also, P, As,
In the case of Sb, Bi, S, Se, Te, etc., since the vapor pressure is high especially at the dissolution temperature of the base composition, it is difficult to add more than 2% in total, and B having a low vapor pressure also exceeds 2%. And the coercive force Hc increases, which is not preferable. Therefore, the total amount is 2
% Addition.

The compound phase at the grain boundary generated by the vapor element group added in this way drops off from the grain boundary with the division of the grain boundary unit during the grinding, is mixed into the powder of the matrix composition, and is further ground as the mixture phase itself. Those having a low melting point are melted and scattered by frictional heat, or become extremely fine residues, and are melted and scattered during the subsequent annealing, and are further reduced, and do not remain to the extent that magnetic properties are deteriorated.

When pulverizing the pulverized raw material to which the pulverization promoting additive element is added, and performing a heat treatment in an atmosphere having a suppressed oxygen potential, the above-described B, P, As, Sb, Bi, S, Se,
The addition of the group consisting of Te further promotes the improvement of the grinding efficiency. The presence of the fragile grain boundary compound phase generated by the addition of the above-described element group reduces the grain boundary energy, thereby making it difficult to recognize a selective grain boundary which is difficult to recognize in a normal Fe-Ni-based alloy to which the upper element group is not added. It is considered that the state is susceptible to oxidation. Atmosphere with reduced oxygen potential, but not at the stage where the oxidation state of grain boundaries can be quantified,
For example, as an atmosphere for heating before grinding, 600 ° C in wet hydrogen
The pulverization efficiency is improved as compared with the case where the preheating is performed, the case where the heat treatment is not performed, and the case where heating is performed in dry hydrogen. The atmosphere is not limited to wet hydrogen, and may be nitrogen, an inert gas such as Ar, an NH ₃ decomposition gas, or the like, and is not particularly limited as long as it is a weakly oxidizing atmosphere containing an oxygen potential.

The temperature may be in a range where the powder to be pulverized starts to agglomerate. However, at a temperature of 1000 ° C. or more, the relative density exceeds 70% to produce a sintered body, which is not preferable because the pulverization efficiency is reduced.

For mechanical pulverization, a stamp mill, a vibration mill, an attritor, and the like can be applied, but B, P, As, Sb, Bi,
One or more of the element group consisting of S, Se, and Te is 0.1 to 2
% Of the Fe-Ni-based alloy powder added, by the attritor with the highest input energy among the pulverizers,
Within 10 hours, it is possible to obtain a flat powder of the target particle size and thickness with almost 100% yield. In the case of ordinary Fe-Ni-based alloy powder to which the above-mentioned elements are not added, pulverization for more than 10 hours is required for reducing the average thickness after pulverization to 2 μm or less.

The above is the case using an attritor. In a pulverizer with a lower input energy such as a stamp mill or a vibration mill, the time factor is shifted to a longer time side as a whole, but the tendency is the same.

Further, the higher the solidification rate during atomization of the pulverized raw material, the smaller the crystal grain size of the powder and the more uniformly and finely the grain boundary compound phase is crystallized, so that the pulverization proceeds more easily.

Therefore, as the atomizing method, a water atomizing method having a high cooling rate is optimal. Furthermore, according to the water atomization, the molten metal is solidified with the irregular shape of the interface due to the shearing force of the water of the spray medium, so that the molten metal is more easily pulverized in shape than a spherical powder such as gas atomized.

Flattening can be further promoted by performing the mechanical pulverization in the presence of a suitable pulverizing aid. The effectiveness of the grinding aid is, for example, as exemplified in the case of amorphous alloy flakes in Japanese Patent Application No. 61-262134, as the grinding progresses, the powder is adsorbed on the activated powder particle surface to suppress the aggregation of the particles, The effect of promoting flattening is the effect of Fe of the present invention.
-Also observed in Ni-based alloys. Effective solid auxiliaries include higher fatty acids such as stearic acid, oleic acid, lauric acid, and palmitic acid; metal soaps such as zinc stearate, calcium stearate, zinc laurate and aluminum laurate; and higher aliphatic acids such as stearyl alcohol. Alcohols, higher fatty acid amines such as ethanolamine and stearylamine, and polyethylene waxes may be used alone or in combination of two or more.
The addition amount is usually 0.1 to 500% by weight. In addition, an organic solvent such as alcohol, glycol, and ester can be used as the liquid auxiliary.

The pulverized powder is classified as necessary to remove large particles. If there are large particles, it is difficult to apply the composition onto a substrate such as a card and the like, and uniform application cannot be performed, resulting in non-uniform characteristics. If the average particle size is 30 μm or less, there is no problem in characteristics.

On the other hand, if the average thickness is larger than 2 μm, the demagnetizing field coefficient in the flat direction becomes large, so that the soft magnetism after coating decreases.

Next, when the flat fine powder of the present application is pulverized,
Since it has a coercive force exceeding / m, the annealing step is an indispensable treatment.

When the fine-powder Fe-Ni-based alloy having large strain is annealed under the same conditions as ordinary bulk material, agglomeration of powder particles, that is, a sintering phenomenon occurs, and the flat shape obtained by mechanical pulverization becomes There is a problem that it is damaged. Therefore, the annealing must be a treatment method capable of releasing strain without causing aggregation of the powder particles and extracting soft magnetism.

In order to prevent agglomeration by a conventionally known method, the annealing temperature must be significantly lowered from about 1100 ° C. in the case of a normal bulk material, and it is impossible to reduce the coercive force of the annealed powder to 400 A / m or less. It was possible. Annealing to release softness by releasing crushing strain is mentioned in the aforementioned Japanese Patent Application No. 58-59268.However, in order to overcome the problem of aggregation and enhance soft magnetism, It does not give a basic knowledge.

The present inventors, in order to prevent aggregation and improve soft magnetism,
By setting the specific component range, it is possible to prevent an increase in annealing temperature by increasing soft magnetism,
High-temperature annealing in a non-oxidizing atmosphere while flowing or moving the Fe-Ni-based alloy fine powder to significantly reduce the high holding power after grinding while suppressing aggregation of the flat alloy fine powder during annealing. Was found.

As the latter equipment for annealing, it is only necessary that the powder particles move so that they do not agglomerate in the soaking zone, and the mechanical or non-oxidizing gas stirs and disperses the flat alloy fine powder to a predetermined temperature. Includes all methods of heating and annealing. For example, it is conceivable to continuously heat the powder filled with leaving a space in the upper part under a stirring state by a rotary stirring blade provided in a width direction in a cylindrical or groove-shaped container. This is an example. Alternatively, as shown in FIG. 2, a method may be employed in which the powder and the non-oxidizing gas are supplied in a countercurrent or cocurrent flow into an inclined rotating cylinder having a stirring blade inside. After the powder is scraped up, the powder is repeatedly annealed while falling in a curtain shape while repeatedly contacting with the heated non-oxidizing gas. FIG. 3 shows a method using a vibrating fluidized bed, in which a non-oxidizing gas is blown and a powder is introduced to form a so-called fluidized bed, and then the fluidized bottom is mechanically vibrated obliquely.
It promotes fluidization and transfers powder in the direction of vibration. As the bottom plate, a perforated plate, a screen or the like is used. Although the position of the heater is not particularly shown in the example of each drawing, a uniform tropical zone is set by internal or external heating.

〔Example〕

Example 1 Various Fe-Ni-based alloy melts shown in Table 1 were subjected to water atomization to obtain powders having an average particle diameter of 30 to 37 µm.

Saturation magnetostriction constant λs measured for ingots of various compositions
Are also shown in the table. These six types of water atomized powder were ground by an attritor. The grinding conditions were such that the weight ratio of the SUJ2 steel ball to the water atomized powder was 3: 1, isopropyl alcohol as a grinding aid was added in the same weight as the water atomized powder, and the mixture was ground at 300 rpm for 10 hours. The resulting powder has an average particle size of 13-16 μm and an average thickness of 0.7-0.9 μm
And the apparent density is 3 to 3 times the true density of the corresponding component.
6%.

After measuring the coercive force Hc of the powder as pulverized, the change in Hc after annealing in a hydrogen stream and the shape of the powder were observed. The annealing apparatus used was a co-rotating rotary cylinder type furnace as shown in FIG. The results are shown in FIG. In the figure, ○ indicates that the crushed shape was maintained, and ● indicates that agglomeration had occurred.

That is, as the degree to which the saturation magnetostriction constant deviates from zero increases, the tendency that the as-crushed Hc increases and the Hc after annealing tends to increase. As long as the coagulation does not start
When annealing at 600 ° C., Hc is preferably 240 A / m or less only for the powders of Nos. 3, ⁶ , and 5, and in this case, each saturation magnetostriction constant λs is 5 × 10 ^−6. , 3 × 10 ^-6 , 1 ×
It is 10 ^-6 .

Example 2 Powders of compositions Nos. 1 to 6 were pulverized with an attritor in exactly the same manner as in Example 1, and then annealed in a vibrating fluidized bed type furnace shown in FIG. In the case of Example 1, the powder was rotationally moved. In this case, since a uniform fluidized state was generated, Hc could be further reduced without agglomeration even at 700 ° C. That is, Hc of 240 A / m or less was obtained with the powders of Nos. 2, 4, 3, 6, and 5. However, in No. 1, HC ≦ 400 A / m could not be achieved.

In this case, each saturation magnetostriction constant λs is 15 × 1
0 ⁻⁶ , −12 × 10 ⁻⁶ , 5 × 10 ⁻⁶ , 3 × 10 ⁻⁶ , 1 × 10 ⁻⁶ . Therefore, if λs is ± 15 × 10 ⁻⁶ , the target Hc can be obtained.

Example 3 Melts of various Fe-Ni alloys shown in the column of Examples in Table 2 were subjected to water atomization to obtain powders having an average particle diameter of 31 to 39 µm.

These powders are ground by an attritor and then
Aimed annealing, the reduction of the coercive force Hc with H ₂ gas stream. Attritor pulverization uses a weight ratio of SUJ2 steel ball to water atomized powder of 3
Ethanol as a grinding aid was added in the same weight as the water atomized powder, and the mixture was ground at 300 rpm. While sampling every 5 hours on the way, when the average thickness became 1 μm or less, pulverization was stopped, sieved with 350 mesh, and -350 mesh.
And the average particle size thereof were measured. Further, annealing was performed at 600 ° C. for 1 hour in a hydrogen atmosphere with a dew point of −60 ° C., and the coercive force Hc was measured. In addition, the shape of the flat fine powder before and after annealing was compared, and it was confirmed that there was no shape change due to annealing.

As the annealing apparatus, an inclined rotary inner cylinder type having a stirring blade inside as shown in FIG. 2 and a furnace in which hydrogen gas and powder were co-flowed were used.

In the column of Example 3 in Table 2, the main components of the test material excluding unavoidable impurities, the saturation magnetostriction constant λs measured in the ingot bulk material, the required pulverization time to reach an average thickness of 1 μm,
It shows the yield of -350 mesh, the average particle size at -350 mesh, and the coercive force Hc of the flat fine powder after annealing.

From the viewpoint of the saturation magnetostriction constant λs, it can be seen that if it is within ± 15 × 10 ⁻⁶ , the target Hc after annealing can be obtained at 240 A / m or less even if there are various differences in the average grain size. However, λs
At 26 × 10 ^-6 , Hc ≦ 400 A / m cannot be reached.

From the viewpoint of grinding efficiency, the composition of No. 14, 18, 19, 20, 21, 22, 25, 26, 27, 28, 30, which produces the brittle grain boundary compound phase of the present invention, under the grinding conditions of 10 hours Is enough, -350mesh
It can be seen that the yield exceeds 75% and the average particle size is 20 μm or less. In particular, the difference in grindability between the composition of the present invention and the ordinary Fe—Ni alloy composition is remarkable for alloys having the same λs.

On the other hand, in Nos. 16 and 17 where only a small amount of the pulverization promoting element was added, the pulverization time required 15 hours. In addition, Nos. 11, 13, 15, 23, and 29, which do not contain these elements, have a grinding time of -3.
Somewhat dissatisfied with the yield of 50mesh.

Example 4 In the same manner as in Example 3, water atomized powders having compositions No. 18 and No. 25 of the present invention were pulverized. The powder was heat-treated at 700 ° C. for 1 hour in wet hydrogen at a dew point of 30 ° C. before the attritor pulverization.
By this treatment, the powder was formed into an aggregate that could be loosened by hand. The apparent particle size is about 300 μm.

When the upper air mass granular powder was pulverized with an attritor under the same conditions as in Example 3, the results in the column of Example 4 in Table 2 were obtained. That is, the -350 mesh yield after the same 10-hour pulverization was 9
% And 3%, and both of the average particle diameters decreased by 3 μm. In addition, Hc after annealing was the same level value as when the heat treatment was not performed, that is, 200 and 140 A / m, respectively.

Example 5 Of a multi-element permalloy (PC permalloy) to which Mo, Cu, and Mn are added, a molten alloy of a composition having a high magnetic permeability, which is expected to be applied particularly in the field of magnetic shielding, is subjected to water atomization to obtain an average particle size. A powder having a diameter of 29 to 35 μm was obtained. These powders were pulverized by an attritor in the same manner as in Example 3, and thereafter,
Aimed annealing, the reduction of the coercive force Hc with H ₂ gas stream. Attritor pulverization uses a weight ratio of SUJ2 steel ball to water atomized powder of 3
As one, isopropyl alcohol as a grinding aid was added in the same weight as the water atomized powder, and the mixture was ground at 300 rpm. The pulverization time was the same as in Example 3, sampled every 5 hours, and when the average thickness became 1 μm or less, the pulverization was stopped, and the yield and average grain size were measured. Further, annealing was performed under the same conditions as in Example 3, and the coercive force Hc was measured.
The column of Example 5 in Table 2 shows the main components of the test material excluding unavoidable impurities and the measurement results.

Also in this alloy composition, in the same manner as in Example 3, in Nos. 32, 33, and 35 in which brittle grain boundary compound phases are formed, flattening progresses in a short time, and the yield of -350 mesh exceeds about 90% or more. It can be seen that the average particle size is 20 μm or less.

Example 6 Melts of various soft magnetic alloys shown in Table 3 were atomized with water to obtain powders having an average particle size of 25 to 36 µm.

These powders are pulverized by an attritor, and then H ₂
Annealing was performed in an air current to reduce the coercive force Hc. The attritor powder was prepared by adding SUJ2 steel balls and water atomized powder at a weight ratio of 10: 1, adding isopropyl alcohol as a grinding aid in the same volume as the steel balls, and grinding at 300 rpm. Grinding time is 5
Performed in time. After pulverization, the mixture was sieved with a 500 mesh, and the average particle size was measured. The particle size distribution was measured by a laser diffraction method.

500 in a hydrogen atmosphere with a dew point of -60 ° C
The sample was annealed at ℃ × 1Hr, and the coercive force Hc was measured. In addition,
By comparing the shapes of the flat fine powder before and after annealing, it was confirmed that there was no change in shape due to annealing.

Next, the annealed powder was mixed with a binder obtained by mixing an acrylic acid-based resin and a urethane-based resin at a ratio of 2: 3, and applied on a polyester substrate to a thickness of 12 to 14 μm. The coercive force Hc and the maximum magnetic permeability μm of the coated substrate in the direction of the substrate surface were measured.

Table 3 shows the main components of the test material excluding unavoidable impurities, the saturation magnetostriction constants λs measured for the ingot bulk materials,
Coercive force Hc, maximum magnetic permeability μm, magnetic flux density B ₈ when a magnetic field of 8 A / cm is applied, average grain system at −500 mesh, coercive force Hc of flat fine powder after annealing, after coating on polyester substrate Shows the coercive force Hc and the maximum magnetic permeability μm in the in-plane direction of the substrate.

Comparing the magnetic properties of the bulk material with the flat fine powder and the magnetic properties after being applied to the substrate, it can be seen that the soft magnetic properties after being applied to the flat fine powder and the substrate are considerably reduced. This is because the effect of shape magnetic anisotropy was obtained by using flat fine powder, and the distortion in the grinding process was 500 ° C.
It is difficult to remove completely by low-temperature annealing.

However, the fact that the magnetic properties of the bulk material are reflected in the flat fine powder and the magnetic properties after being applied to the substrate is the third.
It is clear from the table. In other words, the composition of the alloy of the present invention showing excellent soft magnetism in the bulk material shows even after applying the soft magnetism superior to other compositions to the flat fine powder and the substrate.

From Table 3, it can be seen that depending on the composition, the holding force of Hc ≦ 240 A / m can be satisfied, and that the Hc ≦ 400 A / m can be satisfied, even in annealing at rest at a low temperature (500 ° C.). Understand. In addition, the maximum magnetic permeability μm is slightly lower than that of No. 45 and 46 when the Ni content is out of the range of 70 to 83%, even after coating with the bulk material. Timber,
The coercive force Hc increases after powder and coating, and the maximum permeability slightly deteriorates. When the amount of Cu is more than 6% than No. 47, the maximum magnetic permeability μm decreases significantly both in bulk material and after coating. I understand each. Also, from No. 49, when the Mn content is less than 1%, the maximum permeability μm is low and the coercive force is high, and when the Mn content is more than 2% than No. 50, the coercive force Hc is large. Low magnetic permeability μm.
From this, it can be seen that μm becomes lower in any state without Cu addition, and these cannot satisfy the preferable target Hc ≦ 240 A / m of the coercive force Hc of the present invention by this low-temperature annealing. However, Hc ≦ 400A / m is satisfied.

From the above, the flat fine powder of the component range recommended by the present invention
Nos. 41 to 44 are excellent in soft magnetic properties such as coercive force Hc and maximum magnetic permeability [mu] m even after being coated on a substrate, and show that they exhibit good magnetic shielding properties.

Example 7 The same water atomized powder as No. 41 of Example 6 was ground by an attritor.

The attritor powder was prepared by adding SUJ2 steel balls and water atomized powder at a weight ratio of 10: 1, adding isopropyl alcohol as a grinding aid in the same volume as the steel balls, and grinding at 300 rpm.
The pulverization time was set at 1, 3, 5, and 20 hours for the purpose of changing the thickness and average particle size of the powder. After grinding, 350mesh
Alternatively, the mixture was sieved with a 500 mesh, and the particle size distribution and the powder thickness were measured.

The resulting powder under the same conditions as in Example 6, after annealing in H _2, was measured the coercive force Hc, after coating on a substrate, the coercive force Hc and maximum permeability μm at the substrate surface direction It was measured.

Table 4 shows the attritor grinding time, -350mesh, -5
The average particle size, the average thickness, the coercive force Hc of the flat fine powder after annealing, the coercive force Hc in the in-plane direction of the substrate after coating on the polyester substrate, and the maximum magnetic permeability μm at 00 mesh.

According to Table 4, No. 52, when the wall thickness is more than 1 μm, the coercive force Hc after application is high and the maximum magnetic permeability μm is low because the demagnetizing coefficient in the flat direction is large. It can be seen that ≦ 240 A / m tends to be unsatisfactory.

In No. 54 having an average particle size of more than 30 μm, the average magnetic properties were good, but it was difficult to apply the coating uniformly on the substrate, and the coating film became uneven.

〔The invention's effect〕

As described above, as shown in Examples, if the saturation magnetostriction constant λs is an Fe-Ni-based alloy within ± 15 × 10 ⁻⁶ , the average particle diameter is 0.1
Even if it is a remarkably flat fine powder having a thickness of about 30 μm and an average thickness of 2 μm or less, the coercive force Hc can be reduced to 400 A / m or less by annealing. Further, by stirring and dispersing (flowing and moving) the powder in order to prevent agglomeration of the powder during the annealing, the annealing temperature can be increased, and the effect can be further improved. Further, by specifying the components, the required magnetic properties of the powder and the coating film can be satisfied even by low-temperature annealing that does not cause aggregation.

As described above, according to the present invention, a flat fine powder having excellent soft magnetism can be obtained, and its industrial value is great.

Further, as shown in the examples, B, P, As, and S were added to the compositions of the present invention in which the saturation magnetostriction constant λs was within ± 15 × 10 ^−6.
b, Bi, S, Se, Te
Flat Fe-Ni alloy powder with an average grain size of 0.1 to 30 µm, an average thickness of 2 µm or less, and a coercive force Hc of 400 A / m or less is obtained by subjecting the Fe-Ni-based alloy powder added to 0.1% to 2% to pulverization. Fine powder can be produced efficiently, and its industrial value is great.

[Brief description of the drawings]

1 to 3 show examples of an annealing apparatus for carrying out the present invention, and FIG. 4 shows the relationship between the coercive force of the pulverized powder and the annealing temperature according to the present invention. 2: powder supply port, 3: gas inlet, 5: powder outlet, 7: gas outlet

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) B22F 1/00 B22F 9/04 H01F 1/20

Claims (9)

(57) [Claims] 1. A composition having a composition in which a saturation magnetostriction constant λs measured in a bulk material is within ± 15 × 10 ⁻⁶ and an average particle size of 0.1 to 30 μm.
m, an average thickness of 2 μm or less, a coercive force Hc of 400 A / m or less, and a flat Fe-Ni alloy fine powder obtained by subjecting a raw material powder to mechanical pulverization and annealing. 2. Ni 70-83%, Mo2-6%, Cu3-6%, Mn1
The flat Fe-Ni according to claim 1, wherein the content of C is 0.05% or less, and the balance is iron and incidental impurities.
System alloy fine powder. 3. An element group consisting of B, P, As, Sb, Bi, S, Se and Te, wherein one or more elements are 0.1% or more and 2% or more.
3. The method according to claim 1, wherein:
2. The flat Fe-Ni alloy fine powder described in 1. above. 4. A raw material having a composition having a saturation magnetostriction constant λs of ± 15 × 10 ^{−6 or} less measured by a bulk material is pulverized to an average grain size of 0.1 to 30 μm and an average thickness of 2 μm or less. After annealing in a non-oxidizing atmosphere while substantially maintaining the above flat fine powder state, the coercive force Hc of the powder to 400A / m or less of flat Fe-Ni-based alloy fine powder Production method. 5. The raw material to be pulverized has a saturation magnetostriction constant λs measured for a bulk material within ± 15 × 10 ^-6 and B, P, As, S
The flat Fe-Ni alloy fine particle according to claim 4, characterized in that it contains one or more of 0.1% or more and 2% or less of an element group consisting of b, Bi, S, Se, and Te. Powder manufacturing method. 6. The flat Fe-based material according to claim 5, wherein prior to the pulverization, the raw material powder to be pulverized is subjected to a heat treatment in an atmosphere having a suppressed oxygen potential.
Manufacturing method of Ni-based alloy fine powder. 7. The method for producing a flat Fe-Ni-based alloy fine powder according to claim 4, wherein the annealing is performed while the powder is flowing or moving. 8. The flat Fe according to claim 4, wherein the raw material to be pulverized is an irregularly shaped alloy powder obtained by spraying a molten alloy by water atomization. -Method for producing Ni-based alloy fine powder. 9. The method for producing a flat Fe-Ni-based alloy fine powder according to claim 4, wherein the mechanical pulverization is performed in the presence of a pulverization aid.