JPH0639643B2 - Method for producing magnetic composite material of A1 or A1 alloy - Google Patents

Abstract

PURPOSE:To obtain a composite material excellent in magnetic properties such as initial magnetic permeability, by subjecting a ferromagnetic material to oxidation by heating before or after precompacting and then by pressing and impregnating molten Al into the resulting preformed body. CONSTITUTION:A powder or fibrous body of ferromagnetic material consisting of Fe or Fe alloy is precompacted. Before or after the above precompacting,the above material is subjected to oxidation by heating in the air at 300-700 deg.C to undergo formation of oxide film on the surface. The resulting preformed body 2 is disposed in a metal mold 3, and molten Al or Al alloy 1 is poured around the preformed body 2. Then, a pressurizing force is impressed by means of a plunger 6, etc., on the poured molten Al 1, and the molten Al 1 is pressed and impregnated into the preformed body 2 so as to form a magnetic composite material. Since this composite material has high magnetic properties, it can contribute toward making magnetic substances, etc., for motor rotor and stator lightweight.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention has excellent magnetic properties, particularly excellent initial magnetic permeability.
Alternatively, it relates to the production of a magnetic composite material of A1 alloy.

[Conventional technology]

A-1 or A-1 alloy (hereinafter abbreviated as "A-1") is excellent in electrical conductivity, thermal conductivity, corrosion resistance, and workability in addition to being lightweight, and is alloyed. In addition, the strength has been improved in recent years, resulting in particularly lighter weight.
It is widely used as a substitute for steel in the field of electrical products, where miniaturization is proceeding rapidly.

On the other hand, "A-1" is a non-magnetic material and cannot be applied to magnetic parts such as motors. For these parts, ferromagnetic Fe or Fe alloy is used. It is normal.

However, in the field of electric products, it is strongly desired to reduce the weight of these magnetic components as well, and a lightweight and magnetic material is required.

In order to meet such a demand, development of a magnetic composite material having the property of “A (1)” and further magnetism is advanced, and various specific proposals have been made regarding the manufacturing method thereof.

As a method of manufacturing these "A1" magnetic composite materials,
There are two types, one is a powdered metallurgy method and the other is a molten metal impregnation method. As a method for producing a magnetic Al alloy by a powder metallurgy method, for example, Japanese Patent Application Laid-Open No. 57-51231.
There is one disclosed in the publication.

The method of manufacturing a magnetic composite material according to this conventional technique is described in "A ▲
1) powder or cutting powder and ferromagnetic metal or alloy powder or cutting powder are mixed in a weight ratio of 20: 1 to 1: 1 and compression-molded. "Sintering at a temperature equal to or lower than the melting point of" by the so-called powder metallurgy method
If necessary, after sintering, hot forming such as forging and extrusion is added at a temperature of the melting point or lower.

This prior art is based on the above-mentioned powder metallurgy method, in which "A (1)" magnetism is obtained by mixing and containing "A (1)" with a ferromagnetic material such as iron powder and low carbon steel cutting chips. A composite material is manufactured.

Further, as a method for producing the "A-1" magnetic composite material by the molten metal impregnation method, for example, Japanese Patent Application Laid-Open No. 60-103141
There is one disclosed in the publication.

The manufacturing method of the A1 composite material according to this conventional technique is as follows.
A volume ratio of 5 formed by an alloy (1) and a fibrous or particulate reinforcing material (whisker of a ferromagnetic metal such as Fe, Ni, Co) having a melting point higher than that of the alloy A (1). ~ 70% of the preform is filled in a metal capsule having a melting point higher than that of the Al alloy, the capsule is vacuum-sealed, and then heated to heat the Al alloy in the capsule. Is melted, and the capsule is isotropically pressurized via a pressure medium to plastically deform the capsule, while melting the inside of the capsule.
(3) The alloy (1) is made into a composite with a ferromagnetic metal by a so-called molten metal impregnation method in which a preformed body is impregnated with the alloy.

When the molten metal of the Al alloy is used,
An impregnation pressure of 1000-2000 atmospheres is adopted, and
The processing time is about 15 to 60 minutes.

In this conventional technique, a molten metal of A1 alloy is press-fitted and impregnated into a preformed body made of a ferromagnetic metal by the molten metal impregnation method.
It is intended to produce an Al composite material having high true density and excellent mechanical properties.

Further, as a method for producing an A (l) composite material by so-called melt impregnation method for producing an A (l) composite material by pressure casting an A (l) melt, for example, Japanese Patent Application Laid-Open No. 60-
There is one disclosed in No. 25222.

The method for producing a composite material according to this conventional technique is to inject a molten metal of a parent phase metal such as A (1) and Mg into a mold in which a preformed body made of reinforcing fibers such as carbon fibers is placed, By pressurizing and impregnating into the preform by so-called molten metal impregnation method, in which molten metal pressure is rapidly applied to a first predetermined pressure within a first predetermined time from the start of pressurization. , Immediately the second lower than the first predetermined pressure
The pressure is reduced to a predetermined pressure and is maintained for a second predetermined time.

According to this prior art, the molten metal impregnation method allows the molten metal A to be uniformly permeated with a relatively low pressure even for a preform made of reinforcing fibers having a low molten metal permeability. It is intended to produce a composite material having excellent mechanical properties, that is, A1 composite material, in which A1 and reinforcing fibers such as carbon fibers can be firmly bonded.

In addition, according to this conventional method, when the preformed body made of carbon fiber and having a volume ratio of 18% was press-impregnated with the molten metal A, the first predetermined pressure was set to 1000 to 20.
00kg / cm ² , 1st predetermined time within 1 second, 2nd predetermined pressure 7
It is said that good results of impregnation of the molten metal A can be obtained under the molten metal pressurization condition of 50 kg / cm ² and the second predetermined time of 60 seconds.

[Problems to be solved by the invention]

In the production of the "A-1" magnetic composite material, the ferromagnetic material added / contained in the "A-1" is allowed to sufficiently exhibit the inherent magnetic properties, and is compounded with the "A-1". For that purpose, in order to do so, in the process of forming the composite, strain should not be added to or left in the ferromagnetic material, and the reaction of the ferromagnetic material with "A ▲" should be suppressed. Is the point.

This is because, if there is strain inside the ferromagnetic material, this strain hinders the movement of the domain wall when a magnetic field is applied, and thus reduces the magnetic susceptibility in the ferromagnetic body, that is, in the manufacturing process of the magnetic composite material. This is because when a strain is added to and retained in the ferromagnetic material added therein by the molding stress, the strain lowers the magnetic susceptibility of the magnetic composite material, particularly the initial magnetic permeability.

Then, the ferromagnetic material (Fe or Fe alloy) and “A ▲
When there is thermal diffusion / reaction at the interface with "l ▼" (A ▲ l ▼ or A ▲ l ▼ alloy), brittle and non-magnetic intermetallic compounds (A ▲ l ▼ ₃ , Fe, etc.) are generated by this reaction. Is generated. That is, when a non-magnetic intermetallic compound is generated between the ferromagnetic material therein and "A" by the heat applied in the manufacturing process of the magnetic composite material, the ferromagnetic material serves as a magnetic body. This is because the effective volume is reduced, and the magnetic composite material of "A1" is simply increased in weight for the loss, but the magnetic characteristics cannot be improved.

However, the above-mentioned magnetic composite material and A
From the above viewpoints, it was found that the ferromagnetic material added therein cannot sufficiently exhibit its original magnetic characteristics.

That is, in the prior art by the above-mentioned powder metallurgy method (proposal of Japanese Patent Laid-Open No. 57-51231), "A.ltoreq."
The temperature of compression molding / sintering and the subsequent hot forming process of the magnetic composite material is set to the melting point of "A1" (about 480 to 650 ° C) or less, and the temperature range is relatively low. The ferromagnetic material in the "A-1" magnetic composite material which has been solidified and hot-molded cannot necessarily release the strain applied during the molding process, and inevitably remains inside. Will be things.

For example, a mixture of pure Al powder and pure Fe powder may be mixed with about A
Regarding compression and solidification at 600 ° C, which is lower than the melting point (about 660 ° C) of (1), it is necessary to apply a pressure of about 5000 to 8000 kg / cm ^{2 in} order to ensure the bonding and integration of these powders. The stress applied to pure Fe powder at this pressure greatly exceeds the yield stress of pure F (about 3 kg / mm ² = 300 kg / cm ² ) at a temperature of 600 ° C. Strain is added to the inside of pure Fe by the stress applied in the compression solidification process, and this strain cannot be released and removed in a short time at a temperature of about 600 ° C.

Therefore, "A ▲ l ▼" magnetic composite materials of these powder metallurgy, shall apply in a relatively low temperature heating temperature of the manufacturing process, inhibiting the formation of intermetallic compounds _{(A ▲ l ▼ 3 · Fe} ) Even if it is effective in terms of surface, the strain added by the stress in the molding process remains inside the magnetic material added inside it, and the magnetic characteristics expected from the amount of added ferromagnetic material Is something that cannot be obtained.

For example, pure iron has a magnetic flux density of about 20,000 gauss (G) in a low magnetic field of 100 oersteds (Oe), and this pure iron is 30% in volume ratio in pure A (l). It is expected that the magnetic composite material with the mixed attachment will show a magnetic flux density of about 6,000 gauss (G) in the above magnetic field, when calculated assuming that the mixed rule is obeyed.

However, for example, a magnetic composite obtained by hot compression molding a mixture obtained by adding pure iron 30% by volume in pure Al powder at 600 ° C. and 7,000 atm (corresponding deformation stress ≈ 70 kg / mm ² ). The material had a magnetic flux density of 3500 gauss (G) in a magnetic field of 100 Oersted (Oe), which was much lower than the expected value.

Although the strain inside the ferromagnetic material in the "A-1" magnetic composite material according to the above-mentioned conventional technique can be removed by applying annealing at an appropriate temperature and time after completion of molding, respectively. However, since this annealing temperature maintains the morphology of the magnetic composite material, “A ▲ l” in the magnetic composite material is maintained.
Only the melt-down temperature of "▼", that is, the temperature below the melting point of "A ▲ l", can be applied, and strain at the relatively low temperature (about 450 to 650 ° C) can reduce strain inside the ferromagnetic material. In order to remove it, the required time becomes a long time which is practically difficult to apply.

On the other hand, the prior art by the above-mentioned molten metal impregnation method (JP-A-60
-103141), "A (1)" is heated and melted in a state where it is filled in a capsule together with a preform of a ferromagnetic material, and thereafter, the preform is compressed and deformed with the preform. It is impregnated into the molten steel and is melted in the process of heat melting and pressure impregnation.
Inevitably a reaction occurs at the interface between the ▼ ”and the ferromagnetic material,
Intermetallic compound _{(A ▲ l ▼ 3 · Fe} ) is generated. In addition, in this conventional technique in which the ferromagnetic material is mixed even in the temperature rising process for heating and melting of "A1", "A
(1) ”and the ferromagnetic material (Fe or Fe alloy) at the interface (reaction between A (1) and Fe observed at 550 ° C. when a certain time is given) gives a relatively long time. The production of intermetallic compounds is promoted, and the ferromagnetic material added therein greatly reduces the effective volume as a magnetic material.

Further, in the prior art by the latter molten metal impregnation method (proposal of Japanese Patent Publication No. 60-25222), it is said that a reinforcing fiber body such as a carbon fiber is impregnated with A (1) to form a composite, Although it is mentioned that strengthening A1 as a parent phase metal by this complexing, that is, improving mechanical properties, it is a composite of A1 and a ferromagnetic material, or a ferromagnetic material by complexing. There is no mention or suggestion of any influence on the magnetic properties of the material.

Further, according to this conventional technique, when the reinforcing fiber is replaced with a ferromagnetic material to produce a magnetic composite material that is a composite of "A1" and a ferromagnetic material (Fe or Fe alloy), The impregnation pressure is comparatively lower than the solidification molding pressure by the powder metallurgy method, and although it is significantly advantageous in terms of strain to be added or retained inside the ferromagnetic material, the impregnation / solidification time is relatively short. Nevertheless becomes time, reaction with a ▲ l ▼ and Fe in the process of melt impregnation and coagulation, namely intermetallic compounds _{(a ▲ l ▼ 2 · Fe} ) difficult generation of avoiding, ferromagnetic material "a ▲ l ▼ In the process of forming a complex with ", the effective volume as a magnetic body is reduced.

Therefore, the magnetic composite material according to these melt impregnation method, with the formation of intermetallic compounds _{(A ▲ l ▼ 3 · Fe} ) at the interface of the ferromagnetic material serving as molten metal "A ▲ l ▼" in the manufacturing process, the There is a drawback that the ferromagnetic material added inside reduces the effective volume as a magnetic material.

In view of the above problems, the present invention provides an interface between a ferromagnetic material (Fe or Fe alloy) added therein and "A1" (A1 or A1 alloy) in the manufacturing process. Reaction, that is, a non-magnetic intermetallic compound (A ▲ l
▼ ₃・ Fe) generation can be suppressed, and strain added or retained inside the ferromagnetic material can be reduced, and the ferromagnetic material added therein has sufficient original magnetic characteristics. It is an object of the present invention to provide a method for producing a magnetic composite material of A (1) or an alloy of A (1) that can be exhibited in any of the following.

[Means for solving problems]

The method for producing a magnetic composite material of A1 or A1 alloy according to the present invention for solving the above-mentioned problems includes a method of preforming powder or fibrous body made of Fe or Fe alloy, A method for producing a magnetic composite material containing 15 to 80% by volume of the ferromagnetic material by press-fitting and impregnating a molded body with a molten metal of A1 or A1 alloy, Before or after preforming, it is heated and oxidized in the atmosphere at a temperature of 300 to 700 ° C., and thereafter, the molten metal is press-impregnated into a preformed body made of the heat-oxidized ferromagnetic material. To do.

[Action]

A method of manufacturing a magnetic composite material of A (1) or A (1) alloy according to the present invention includes a preformed body formed of powder or fibrous body of ferromagnetic material made of Fe or Fe alloy,
Aℓ or Aℓ alloy melt is press-fitted and impregnated,
The so-called molten metal impregnation method is used to form a composite of "A-1" and a ferromagnetic material, and the pressure required for forming the composite, that is, the impregnation pressure of the "A-1" molten metal is so-called. The pressure required to form a composite by powder metallurgy, that is, "A ▲
It is lower than the pressure to compress and bond in the solid phase temperature range of "l ▼", and it reduces the addition or residual strain inside the ferromagnetic material added in the complex formation process. It is possible.

Further, in the method of the present invention, the ferromagnetic material is one which is heated and oxidized in the atmosphere before or after preforming to form an oxide film on the surface of the ferromagnetic material. The preformed body made of the material is
l ▼ "is intended to suppress the formation of non-magnetic become intermetallic compounds during press-impregnation of the molten metal _{(A ▲ l ▼ 2 · Fe} ).

This is because when a preform made of a ferromagnetic material having an oxide film formed on its surface is press-impregnated with the molten metal of "A1" by impregnation, the molten metal of A1 and F at the interface between the molten material and the ferromagnetic material are used.
Although it reacts with e, an oxide film is present at this interface, that is, on the surface of the ferromagnetic material, and this oxide film acts as a barrier that inhibits the reaction between A and Fe. it is from inhibiting the production of intermetallic compounds _{(a ▲ l ▼ 3 · Fe} ).

To explain in more detail, the inventors of the present invention, when using the molten metal impregnation method for the production of the magnetic composite material, even if the impregnation pressure is reduced to a pressure low enough to discharge the gas in the preform, It has been confirmed that it is possible to form a composite of "1""and a ferromagnetic material, and the deterioration of the magnetic properties due to the strain inside the ferromagnetic material added therein can be greatly improved.

However, when by the melt impregnation method, the generation of "A ▲ l ▼" interfacial reaction of the molten metal and the ferromagnetic material occurs inevitably, intermetallic compounds of a non-magnetic due to the reaction _{(A ▲ l ▼ 3 · Fe} ) Since this involves the problem of depleting the effective volume of a ferromagnetic material as a magnetic material, the present invention has investigated various methods of suppressing this interfacial reaction, and as a result, an oxide film is formed under certain conditions in the ferromagnetic material. It was concluded that this oxide film, when formed, can be a barrier to effective interfacial reaction.

In order to prevent the interfacial reaction between the molten metal "A1" and the ferromagnetic material, a material that can be a barrier to the interfacial reaction on the surface of the powder or fibrous material of the ferromagnetic material, such as vapor deposition or plating, can be used. It is possible to coat at
In order to effectively coat the surface of a powder or fibrous body having a large surface area, the production cost is inevitably increased, and it is not always easy to find an appropriate and effective coating material.

Therefore, the inventors of the present invention focused on the formation of a coating by heating oxidation which is very simple and low in cost. Generally, oxides such as Fe are called thermite between A and l when heat intervenes. It is said to cause a violent reaction, and such a combination is difficult to expect for its practicality.

However, as a result of various experiments, the inventors of the present invention did not recognize the above-mentioned violent reaction in the molten metal impregnation method of "A (l)", and moreover, it was oxidized by heating in the atmosphere at an appropriate temperature range. At this time, the oxide film formed on the surface of the ferromagnetic material made of Fe (or Fe alloy) can be an effective barrier for inhibiting the reaction between "A1" and the ferromagnetic material in the process of the molten metal impregnation. It was a finding.

Among these experimental examples, 0.01-0.02mm diameter, 1-5mm
A preform with a volume ratio of 50% formed from a low-carbon steel (S15C) short fiber body with a length is heated and oxidized in the atmosphere at various temperatures and times, and then a molten metal of pure A (l) is added. Regarding the magnetic composite material produced by press-fitting and impregnating at 300 atm,
Magnetic Flux Density (Gauss) in 100 Elsted (Oe) Magnetic Field
The result of measurement is shown in the graph of FIG.

The numbers entered in the graph of FIG. 1 indicate the respective heating times, and the plots marked with △ and × indicate the results of experiments conducted for comparison. Those marked with X are heat-treated under N ₂ gas atmosphere, and those marked with X are heat-treated under Ar gas atmosphere.

As is clear from the graph of FIG. 1 showing the relationship between the heating temperature / time of the magnetic material in the atmosphere and the magnetic properties of the magnetic composite material, the ferromagnetic material heated and oxidized at the heating temperature of 300 to 700 ° C. The magnetic properties of the alloys are much better than those of other temperature regions.

And within the above temperature range, the heating time is within a range (about 1 to 8 hours) applicable to normal heat treatment,
It can be seen that it does not make a big difference in the effect.

This is because the oxide film formed on the surface of the ferromagnetic material at a temperature of less than 300 ° C. cannot act as an effective barrier that inhibits the reaction with A (1) during the impregnation of the molten metal.
This is because the oxidation effect on the surface of the ferromagnetic material becomes too strong in the temperature range exceeding ℃, and the ferromagnetic material is oxidatively worn.

The preform is made of a ferromagnetic material in advance of 15-80.
Since the preform has to withstand the inflow pressure of the molten metal, the preform is required to have a volume ratio of 15%.
This is because if it is less than 80%, the inflow pressure of the molten metal cannot be maintained and its shape cannot be maintained, and if it exceeds 80%, the continuity of voids in the preform is interrupted and the molten metal cannot sufficiently permeate. .

As described above, the magnetic composite of the present invention A-1 or A-1 alloy in which the "A1" molten metal is press-fitted and impregnated into the preformed body made of a ferromagnetic material having an oxide film formed on the surface thereof. The method of manufacturing the material is to form a composite with relatively lower stress than that by the powder metallurgy method, and it is possible to reduce the addition or residual strain inside the ferromagnetic material added therein, And the interfacial reaction between the ferromagnetic material made of Fe or Fe alloy and the molten metal of A (l) or A (l) alloy,
That it is capable enough to exhibit the inherent magnetic properties in the non-magnetic intermetallic compounds _{(A ▲ l ▼ 3 · Fe} ) suppressing give a product of the ferromagnetic material added to them to have.

〔Example〕

Magnetic composite materials were produced under various combined conditions by the molten metal impregnation method.

These magnetic composite materials form various ferromagnetic materials into preforms having a predetermined volume ratio using a binder such as a resin, and heat-treat the preforms under various heating temperatures / time and atmosphere, Insert into the specified mold and insert A into the mold.
{Circle around (1)} The molten metal was injected and pressure-impregnated and coagulated to form a composite.

FIG. 2 exemplifies a part of the molten metal impregnation apparatus used for producing the magnetic composite material, in which a pouring port (4) is provided on the upper surface of a mold (3) having a cylindrical hollow portion. Plunger sleeves (5) are closely arranged. The plunger (6) is fitted in the inner diameter of the sleeve (5) so that it can move up and down, and is driven by a pressurizing mechanism (not shown) to inject a pressing force.
It is applied to the molten metal (1) injected from (4). Also,
The preform (2) made of a ferromagnetic material is preformed in a predetermined volume ratio and placed in the mold (3).

The magnetic flux density (gauss) in a magnetic field of 100 Oersteds (Oe) was measured for each of the magnetic composite materials that had been melt-impregnated with the above-described method and apparatus to form a composite.

The results are shown in Table 1. For comparison, an example of the magnetic composite material by the powder metallurgy method is also shown in Table 1.
This is a method in which the A1 powder and the ferromagnetic material are mixed at a predetermined volume ratio, and the temperature is set to 7,000 at 600 ° C. in the solid phase temperature range of A1.
It is formed by compression solidification under a pressure medium gas at atmospheric pressure.

As shown in Table 1, the magnetic composite materials manufactured in the conditions satisfying the conditions of the method of the present invention (the examples of the examples marked with a circle in the remarks column in the table) are the other conditions. Compared with the magnetic composite materials manufactured in (the ones noted in the remarks column and those marked with x), the magnetic properties were significantly improved, and some of them were It almost satisfies the expected value from the volume ratio.

In addition, in the example shown in No. 2 in which the volume ratio of the ferromagnetic material was 10%, the preform was contracted downward at the time of pouring the molten metal, and the predetermined shape could not be obtained. Further, in the example shown in No. 50 in which the volume ratio was 90%, the molten metal A1 could not be sufficiently permeated into the preform.

And the thing by the powder metallurgical method for comparison (the example in which H is entered in the manufacturing method column) is compared with that of the corresponding method of the present invention (No. 7-No. 8, No. 14-No. 15, No.
16-No.17, No.18-No.19, No.44-No.4
No. 5, No. 46-No. 47), only about half the magnetic characteristics could be obtained.

In the case of the molten metal impregnation method shown in Table 1 (an example in which S is entered in the manufacturing method column), the impregnation pressure, that is, the molten metal injection pressure was 300 to 400 atm. It has been confirmed that if the pressure is equal to or higher than the atmospheric pressure, the gas in the preform is removed, and the molten metal A (l) can sufficiently permeate into the preform, but it is set to measure the permeation more reliably. .

However, it is desirable that the impregnation pressure is equal to or lower than the yield stress of the ferromagnetic material forming the preform at the temperature of the molten metal injected, which is the stress equal to or lower than the yield stress of the ferromagnetic material. This is because no strain remains inside.

Regarding the thermal oxidation applied to the ferromagnetic material prior to the molten metal impregnation, as shown in Examples shown in No. 6, No. 36, and No. 48, the ferromagnetic material is heated at 570 ° C. within the temperature range of the present invention. Regarding the magnetic properties of the magnetic composite material obtained by heating and oxidizing, even if the volume ratio fluctuates to 15%, 50%, 80%, no singular difference is observed in terms of the effect and the magnetic properties increase as the volume ratio increases. Get higher

As can be seen from the examples shown in No. 30, No. 36, and No. 38, even if the form of the ferromagnetic material is changed, the ferromagnetic material heated and oxidized at the temperature within the range of the conditions of the present invention is added therein. The magnetic properties of the lowered magnetic composite material show high values.

For comparison, the one subjected to heat treatment in an inert gas atmosphere instead of the heating and oxidation in the atmosphere (an example in which N ₂ or Ar is entered in the atmosphere column) is compared with that of the corresponding method of the present invention ( No. 9, 10-No. 8, No. 28, 29-No.
27) Then, only about 2/3 of the magnetic characteristics could be obtained.

When observing the cross section of a typical one of these magnetic composite materials, for example, the one of the example of No. 35 shows that
As shown in Fig. 3a, which is a schematic cross-sectional view of the magnetic composite material, an oxide film (Fo) is recognized around the ferromagnetic material (F), but a reaction phase with A (l) (A) is recognized. I couldn't do it.

On the other hand, No. was heated and oxidized at 210 ° C in the atmosphere.
In the example of No. 21 and the example of No. 28 heat-treated under an inert gas atmosphere, as shown in FIG. 3b which is a schematic cross-sectional view of the magnetic composite material, Fe (F)
Reaction product of A with Al (A), that is, an intermetallic compound
(AF) was present and wear of the ferromagnetic material (F) was observed.

Further, in the case of the example of No. 43 which was heated and oxidized at a temperature of 830 ° C., as shown in FIG. 3C which is a schematic sectional view of the magnetic composite material, it was oxidized around the ferromagnetic material (F). Film
(Fo) was observed and the reaction phase with A (l) (A) was not observed, however, the ferromagnetic material (F) was heavily worn due to oxidation, and almost all of the ferromagnetic material disappeared. It has been found.

Regarding the heating and oxidation of the ferromagnetic material prior to the impregnation of the molten metal, in order to obtain a better and stable effect in its implementation, the heating temperature should be set within the range of 400 to 600 ° C. desirable.

As described above, the magnetic composite material according to the present invention sufficiently exhibits the original magnetic characteristics of the ferromagnetic material added therein.

〔The invention's effect〕

A method of manufacturing a magnetic composite material of A1 or A1 alloy according to the present invention comprises a ferromagnetic material and A1 (or A1 alloy) added in the manufacturing process. Interfacial reaction of non-magnetic intermetallic compounds (A ▲ l ▼ ₃
The production of Fe) is suppressed in advance by the oxide film formed on the ferromagnetic material, and the production of a magnetic composite material having the characteristics of A (l) and still having high magnetic characteristics is produced. The magnetic composite material according to the method of the present invention enables magnetic fields for practical motor rotors and stators, high-performance magnetic shields, and other fields of electrical products utilizing magnetism due to its excellent characteristics. In the above, it can greatly contribute to the weight reduction.

[Brief description of drawings]

FIG. 1 is a graph showing the relationship between the heating temperature / time of a ferromagnetic material and the magnetic characteristics of a magnetic composite material in the atmosphere of the present invention. FIG. 2 is a front sectional view showing a molten metal impregnating apparatus used for manufacturing the magnetic composite material of the present invention. FIG. 3a is a schematic view showing a partial cross section of the magnetic composite material. FIG. 3b is a schematic view showing a partial cross section of the magnetic composite material. Fig. 3c
FIG. 3 is a schematic view showing a partial cross section of a magnetic composite material. 1 …… A ▲ l ▼ Molten metal, 2 …… Preform, 3 …… Mold,
4 ... pouring spout, 5 ... plastic sleeve, 6 ... plungeer.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Takashi Motoda 225-84 Mizoguchi, Koji-cho, Kanzaki-gun, Hyogo Prefecture (72) Inventor Keiki Takebayashi 2200-154 (72) Inventor, Inou-cho, Nishi-ku, Nagoya-shi, Aichi Prefecture Koichi Ozaki 2-183 Kitamatsuyama-cho, Seto City, Aichi Prefecture

Claims (1)

[Claims] 1. A powder or fibrous body of a ferromagnetic material made of Fe or an Fe alloy is preformed, and then the preformed body is press-impregnated with a molten metal of A (l) or A (l) alloy. In the method for producing a magnetic composite material containing the ferromagnetic material in a volume ratio of 15 to 80%, the ferromagnetic material is heated in the atmosphere at 300 before or after preforming.
A-l ▼ or A-l ▼, which is characterized in that it is heated and oxidized at a temperature of up to 700 ° C., and then the molten metal is press-fitted and impregnated into a preformed body made of the thermally oxidized ferromagnetic material.
Method for producing magnetic composite material of alloy.