JPS63255332A - Manufacture of magnetic composite material of al or al 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 [Field of Industrial Application] The present invention relates to the production of a magnetic composite material of an Al-Ag alloy that has excellent magnetic properties, particularly excellent initial magnetic permeability.

[Conventional technology]

AI or Al alloy (hereinafter abbreviated as rAeJ) has the advantage of being lightweight, as well as electrical and thermal conductivity.

It has excellent corrosion resistance and workability, and its strength has also been improved through alloying, so it has recently become a substitute for steel, especially in the field of electrical products, where weight reduction and miniaturization are rapidly progressing. It is widely used.

On the other hand, rAIJ is a non-magnetic material and can be applied to parts that utilize magnetism such as motors, and ferromagnetic material Fe or Fe alloy is usually used for these parts.

However, in the field of electrical products, there is a strong desire to reduce the weight of magnetic parts, and there is a need for lightweight and magnetic materials.

In order to meet these demands, efforts are being made to develop magnetic composite materials that retain the properties of rAU while adding magnetism.
Various specific proposals have also been made regarding the manufacturing method.

The manufacturing methods for these rAU magnetic composite materials can be roughly divided into
There are methods for preparing magnetic Al1 alloys by powder metallurgy, and (1) methods for preparing magnetic Al1 alloys by powder metallurgy, such as the one disclosed in JP-A No. 57-51231. .

The method for manufacturing a magnetic composite material according to this prior art is rA
eJ powder or chips and ferromagnetic metal or alloy powder or chips are mixed at a weight ratio of 20 = 1 to 1:1, compression molded, and then Sinter at temperature. This method is based on a so-called powder metallurgy method, and if necessary, after sintering, hot forming processes such as forging and extrusion at a temperature below the melting point are added.

This prior art involves mixing and containing ferromagnetic materials such as iron powder and low carbon steel chips in rAeJ using the above-mentioned powder metallurgy method to produce an rAU magnetic composite material that has the characteristics of both.

(9) As a method for producing an rAU magnetic composite material by a molten metal impregnation method, for example, there is a method disclosed in Japanese Patent Application Laid-open No. 60-103''141.

AI related to this conventional technology! The manufacturing method of the composite material is A1
alloy and fibrous or particulate reinforcement (Fa, Ni, C) with a melting point higher than that of the A1 alloy.

Whiskers of ferromagnetic metals such as
~70% of the preformed body is filled into a metal capsule having a higher melting point than the Al alloy, the inside of the capsule is vacuum-sealed, and then heated to melt the AI1 alloy inside the capsule, The capsule is isostatically pressurized via a pressure medium to plastically deform the turnip 7 while melting the molten A inside the capsule.
The Al alloy and the ferromagnetic metal are made into a composite by a so-called molten metal impregnation method in which the Al alloy is impregnated into a preform.

In addition, when impregnating the above-mentioned molten Al alloy with molten metal, usually 10
An impregnation pressure of 00 to 2,000 atmospheres is used, and the treatment time is about 15 to 60 minutes.

This prior art involves injecting and impregnating a molten A1 alloy into a preform made of a ferromagnetic metal using the molten metal impregnation method described above to produce an Ag composite material with high true density and excellent mechanical properties.

Furthermore, as a method for producing an Ag composite material by pressure casting a molten Ad metal to produce an Ag composite material using the so-called O molten metal impregnation method, for example, Japanese Patent Publication No. 60-25222'
There is a mourning thing disclosed in the issue.

The method for manufacturing a composite material according to this prior art includes arranging a preform made of reinforcing fibers such as carbon fiber, and injecting a molten matrix metal such as Al and Mg into a north mold.
The molten metal is pressurized and impregnated into the preform. This method is based on the so-called molten metal impregnation method, in which a first predetermined pressure is rapidly applied within a first predetermined time from the start of pressurization, and then a second predetermined pressure lower than the first predetermined pressure is immediately applied. The pressure is then lowered to a second predetermined time period.

This prior art is capable of uniformly impregnating Ags molten metal into a preform made of reinforcing fibers with low permeability to %Al molten metal using the molten metal impregnation method at a relatively low pressure. The objective is to manufacture a composite material, that is, an Ag composite material, which can firmly bond a reinforcing fiber such as carbon fiber and has excellent mechanical properties.

In addition, according to this conventional method, when press-fitting and impregnating the preformed body 11 CAI molten metal made of carbon fiber with a volume fraction of 18%, the first predetermined pressure was set at 1000 to 20
00 kgloms, the first predetermined time is within 1 second, the second
Set the predetermined pressure to 750 rams, set the 2nd place, and set the predetermined time to 60
It is said that good impregnation results with Ad molten metal can be obtained under the molten metal pressurization conditions of seconds.

[Problem that the invention seeks to solve]

In the production of rAIJ magnetic composite materials, the rAt? It is necessary to make it into a complex with J, but in the process of making it into a complex, ■
The key points are not to add or leave strain on the ferromagnetic material, and to suppress the reaction between the zero ferromagnetic material and rhj due to heat.

This is because: ■ If there is strain inside the ferromagnetic material, this strain will inhibit the movement of the domain wall when a magnetic field is applied, thereby reducing the magnetic susceptibility inside the ferromagnetic material.In other words, the manufacturing process of magnetic composite materials This is because, when strain is added to and remains in the ferromagnetic material added therein due to the forming stress, this strain reduces the magnetic susceptibility, particularly the initial magnetic permeability, of the magnetic composite material.

And 0 ferromagnetic material (Fs or Fe alloy) and rAl
! When there is a thermal diffusion/reaction at the interface with the A1 alloy (J Due to the heat added during the manufacturing process of the material,
When a non-magnetic intermetallic compound is formed between the ferromagnetic material and 1"xllJ, the ferromagnetic material reduces its effective volume as a magnetic material, and the rAIJ magnetic compound valley material simply weighs the amount of loss. This is because the magnetic properties cannot be improved just by increasing the .

However, the magnetic composite materials and Ad
When methods for producing composite materials were studied from the above viewpoint, it was found that the ferromagnetic material added thereto could not sufficiently exhibit its original magnetic properties.

That is, in the prior art (proposed in JP-A No. 57-51231) using the powder metallurgy method mentioned above, rANJ magnetic composite materials are produced by adjusting the temperature of compression molding, sintering, and subsequent hot forming processing to the melting point of rAeJ ( The ferromagnetic material in the rAIJ magnetic composite material, which is solidified or hot-formed in these relatively low temperature ranges, is added during the forming process. Although the distortion can be released, it will inevitably remain inside.

For example, when compressing and solidifying a mixture of pure Ae powder and pure Fe powder at 600°C, which is below the melting point of pure AN (approximately 660°C), in order to ensure the integration of these powders, it is necessary to It is necessary to apply a pressure of ~8000 kg/a weight 8, and the stress applied to pure Fe powder at this pressure is equivalent to the yield stress of pure Fe at a temperature of 600°C (approximately 3 kFV'mnvm 300 kg/am
The stress applied during this compression and solidification process creates strain inside pure Fa, and this strain can be released and removed in a short time at a temperature of about 600°C. It's something that doesn't exist.

Therefore, these rAIJ magnetic composite materials produced by powder metallurgy require relatively low heating temperatures during the manufacturing process.
Even if it is effective in suppressing the formation of intermetallic compounds (Als/F'8), the strain added by stress during the forming process remains inside the nine-strength material. However, the expected magnetic properties cannot be obtained depending on the amount of ferromagnetic material added.

For example, pure iron exhibits a magnetic flux density of about 20,000 gauss (G) in a low magnetic field of 100 oersted (0), and this pure iron is mixed at a volume ratio of 30! The attached magnetic composite material is expected to exhibit a magnetic flux density of about 6,000 Gauss (G) in the above magnetic field, calculated assuming compliance with the mixture.

However, 1. For example, a magnetic composite material obtained by hot compression molding a mixture of pure AN powder and pure iron at a volume ratio of 30% at 600°C and 7000 atm (corresponding deformation stress ◆ 70 kg Anrn) takes 100 to The magnetic flux density in the magnetic field of Stead (Oe) is 3500 Gauss (G), which is significantly lower than the expected value.

Note that the strain inside the ferromagnetic material in the rAIJ magnetic composite material according to the above-mentioned conventional technology can be removed by annealing at an appropriate temperature and time after completion of molding. However, this annealing temperature In order to maintain the morphology of the magnetic composite material, only a temperature below the meltdown temperature of 0rAIJ in the magnetic composite material, that is, the melting point of rAIJ, can be applied;
The time required for K to remove strain inside a ferromagnetic material at a temperature of 0.degree. C.) is too long to be practically applicable.

On the other hand, the conventional technology using the O molten metal impregnation method mentioned above (Japanese Patent Laid-open No. 60
In the proposal of No.-103141).

rA (IJ is heated and melted while being filled in a capsule with a preformed body of a ferromagnetic material, and then press-fitted into the preformed body as the capsule is compressed and deformed; During the press-in impregnation process, a reaction inevitably occurs at the interface between the molten rAU and the ferromagnetic material, producing intermetallic compounds (AJs/Fe). In the conventional technology, %rAI! is mixed with ferromagnetic material even in a hot process.
The reaction at the interface between J and a ferromagnetic material (F or F alloy) (the reaction between Aj and F, which can be observed at 550°C for a certain amount of time) is given a relatively long time, and the The ferromagnetic material added therein greatly reduces the effective volume of the magnetic material by promoting the formation of intermediate compounds.

In addition, in the latter prior art (proposed in Japanese Patent Publication No. 60-25222) using the zero molten metal impregnation method mentioned above, a reinforcing fiber body KAj such as carbon fiber is impregnated to form a composite. Aj becomes the matrix metal in the embodiment
Although mention is made of strengthening, i.e. improving mechanical properties.

There is no mention or suggestion of the composite of Ad and a ferromagnetic material, or the influence of the composite on the magnetic properties of the ferromagnetic material.

Also, according to this prior art, one reinforcing fiber is replaced with a ferromagnetic material, and rAU and a ferromagnetic material (F or F
When using a magnetic composite material (composite of e-alloy) as a backing, the impregnation pressure is comparatively lower than the solidification and compacting pressure by powder metallurgy, and it is much more effective in terms of strain added or remaining inside the ferromagnetic material. Although it is advantageous, and although the impregnation and solidification time is relatively short, molten metal impregnation and
The reaction between Ad and Fe during the solidification process, that is, the generation of intermetallic compounds (Aes/Fa), is unavoidable, and the effective volume of the ferromagnetic material as a magnetic material is reduced in the process of complexing with rAU. . - Therefore, in the manufacturing process of these magnetic composite materials produced by the molten metal impregnation method, intermetallic compounds (Ags/Fa) are generated at the interface between the ferromagnetic material and the molten metal rAU.
There is a drawback that the ferromagnetic material added therein reduces the effective volume as a magnetic body.

In view of the above-mentioned problems, the present invention has been developed in such a way that the ferromagnetic material (Fe or Fe alloy) added thereto and the r
The reaction at the interface between AIJ (A # - * Bamboo At1 alloy) and O, that is, the nonmagnetic intermetallic compound (Ajs
It is possible to suppress the generation of Fe), and it is possible to reduce the addition or residual strain inside the ferromagnetic material, thereby allowing the ferromagnetic material added therein to fully exhibit its original magnetic properties. The object of the present invention is to provide a method for manufacturing a magnetic composite material of Ad or Al alloy.

□ [Means for solving the problem] In order to solve the above problem, the method for producing a magnetic composite material of A# or Al alloy according to the present invention is a method of manufacturing a magnetic composite material of A# or Al alloy. After preforming the body, the preform body KAlf
Alternatively, in a method for manufacturing a magnetic composite material containing 15 to 80% by volume of the ferromagnetic material by injecting and impregnating a molten metal of A7 alloy, the ferromagnetic material is applied before or after preforming, The method is characterized in that the molten metal is press-fitted and impregnated into a preform made of a ferromagnetic material which has been oxidized by heating at a temperature of 300 to 700° C. in the atmosphere and then oxidized by heating.

[For production]

Al according to the present invention? Alternatively, in a method for producing a magnetic composite material of A1 alloy, a molten metal of AI or Al alloy is press-fitted and impregnated into a preform formed of powder or fiber of a ferromagnetic material made of Fe alloy. The so-called molten metal impregnation method is used to make rhttJ and a ferromagnetic material into a composite, and the pressure required to make the composite, that is, rAe
The impregnation pressure of J molten metal is lower than the pressure required for composite formation by the so-called powder metallurgy method, that is, the pressure for compression fist bonding in the solidus temperature range of rAJJ; This can reduce the addition or residual strain inside the ferromagnetic material added to the ferromagnetic material.

In addition, in the method of the present invention, the ferromagnetic material is heated and oxidized in the atmosphere before or after preforming to form an oxide film on its surface, and the ferromagnetic material has an oxide film formed on its surface. The preformed body made of magnetic material contains intermetallic compounds (AJs) that appear non-magnetic during press-in impregnation with the rAU molten metal.
・Fe) is suppressed from being produced.

This is because when a preform made of a ferromagnetic material with an oxide film formed on its surface is press-impregnated with molten rAIJ, AII and Fe do not react at the interface between the molten metal and the ferromagnetic material. An oxide film exists on this interface, that is, the surface of the ferromagnetic material 1, and this oxide film acts as a barrier to inhibit the reaction between AN and Fe, suppressing the formation of intermetallic compounds (Aes/Fe). Because it does.

To explain the above in more detail, the inventors have discovered that when using the molten metal impregnation method in the production of magnetic composite materials, the impregnation pressure is reduced to a pressure as low as necessary to exhaust the gas in the preform. However, it is possible to form a composite of AeJ and a ferromagnetic material.

It has been confirmed that the deterioration of magnetic properties due to strain inside the ferromagnetic material added thereto can be significantly improved.

However, when using the above molten metal impregnation method, an interfacial reaction between the rAJJ molten metal and the ferromagnetic material inevitably occurs, and this reaction causes the formation of non-magnetic intermetallic compounds (Als/Fa). 1 The present invention and others investigated various ways to suppress this interfacial reaction, and found that 1. When an oxide film is formed on a ferromagnetic material under certain conditions, this oxidation The conclusion was reached that the coating can act as an effective barrier to interfacial reactions.

In order to prevent the interfacial reaction between the rAllJ molten metal and the ferromagnetic material, the powder of the ferromagnetic material is coated on the surface of the fiber body with a method such as vapor deposition or plating, which can act as a barrier to inhibit the interfacial reaction. However, applying an effective coating to the surface of a powder or fiber with a large surface area inevitably involves an increase in manufacturing costs.
Furthermore, it has not always been easy to find suitable and effective sooting materials.

Therefore, the present inventors focused on forming a film by thermal oxidation, which is extremely simple and low cost, but in general, oxides such as Fe cause a violent reaction called thermite with AI when heat is involved. It is said to cause
It was difficult to expect such a combination to be practical.

However, as a result of various experiments, the present inventors have found that in the rAtlJ molten metal impregnation method, such a violent reaction as described above was not observed, and that when heated and oxidized in the air at an appropriate temperature range, F. In addition, we have discovered that the oxide film formed on the surface of the ferromagnetic material made of ijF'e alloy can act as an effective barrier to inhibit the reaction between rAIJ and the ferromagnetic material during the process of impregnation with the molten metal. be.

Among these experimental examples, (LOI~α02rywn diameter, 1~
A preform with a volume ratio of 50% made of short fibers of low carbon steel (815C) with a length of 5 mm was heated and oxidized in the atmosphere at various temperatures and times, and then a molten metal of pure Aj was heated to 300 atm. Regarding magnetic composite materials manufactured by press-in impregnation in! The magnetic flux density (Gauss) in the 00~Stead (Oe) porcelain was measured and the tentative results are shown in the graph of Figure 1.

The numbers written in the graph in Figure 1 indicate the respective heating times, and the plotted △ and x marks indicate the results of experiments conducted for comparison. , those marked with Δ were heat treated under a Nz gas atmosphere, and those marked x were heat treated under an Ar gas atmosphere.

As is clear from the graph in Figure 1, which shows the relationship between the heating temperature and time of magnetic materials in the atmosphere and the magnetic properties of magnetic composite materials, ferromagnetic materials are heated and oxidized at heating temperatures of 300 to 700°C. The magnetic properties of materials in other temperature ranges are far superior to those in other temperature ranges.

If the heating time is within the above temperature range and is within the range applied to normal heat treatment (1 to 8 hours in between),
It can be seen that there is no significant difference in effectiveness.

This is because the nonaqueous oxide film formed on the surface of ferromagnetic materials at temperatures below 300°C can act as an effective barrier to inhibit the reaction with AI during impregnation with molten metal, but on the other hand, at temperatures above 700°C, This is because the oxidation effect on the surface of the ferromagnetic material is too strong, causing oxidation loss of the ferromagnetic material.

In addition, the preformed body is made of a ferromagnetic material with a concentration of 15 to 80
Please note that the preform must withstand the inflow pressure of the molten metal, so that the volume ratio is 15%.
If it is less than 80%, it will not be able to withstand the inflow pressure of the molten metal and maintain its shape, and if it exceeds 80%, the continuity of the voids in the preform will be interrupted and the molten metal will not be able to penetrate sufficiently. It is.

The method for manufacturing the magnetic composite material of the AI or A1 alloy of the present invention involves press-impregnating rAllJ molten metal into a preform made of a ferromagnetic material on which an oxide film is formed on the surface, as described above, by a powder metallurgy method. It can be made into a composite with relatively low stress, and it can reduce the addition or residual strain inside the ferromagnetic material, and it can be made from F'e or Fe alloy. ferromagnetic materials and At
t7'h is an interfacial reaction between the A2 alloy and the molten metal, which can suppress the formation of non-magnetic intermetallic compounds (Ajm・F), which is added to the ferromagnetic material and gives the original magnetic properties to the ferromagnetic material. It is possible to fully demonstrate this.

Example C] Magnetic composite materials were produced by the molten metal impregnation method under various combinations of conditions.

These magnetic composite materials are made by preforming various ferromagnetic materials with a predetermined volume ratio using a binder such as resin, and heat-treating the preform at various heating temperatures and times under various atmospheres. Insert it into a predetermined mold, and place A into the mold.
1 molten metal was injected, and the composite was formed through pressurized impregnation and solidification.

FIG. 2 shows a part of the molten metal impregnation device used to manufacture the above-mentioned magnetic composite material. 4) are arranged closely together. The pufunja (6) is fitted into the inner diameter of the sleeve (5) so as to be able to move up and down freely, and is driven by a pressurizing mechanism (not shown in Figure 1) to apply pressurizing force to the molten Al (1) injected from the pouring port (4). Add to. Further, a preformed body (2) made of a ferromagnetic material is molded in advance at a predetermined volume ratio and placed in a mold (8).

The magnetic flux density (Gauss) in a magnetic field of 100 oersted (Oe) was measured for each of the good magnetic composite materials that were impregnated with molten metal using the above method and apparatus and made into composites.

These results are shown in Table 1 of Fukihanji Confucianism, and for comparison,
An example of a magnetic composite material made by the powder metallurgy method is also listed in Table 1, and this is made by mixing Al powder and a ferromagnetic material at a predetermined volume ratio, and heating it to 600 ° C. in the solidus temperature range of A#. It was compressed and solidified under pressure medium gas at 7000 atmospheres.

(Left below) As shown in Table 1, the magnetic composite materials manufactured under conditions that satisfy the conditions of the method of the present invention (examples marked with O in the remarks column of the table) are as follows: Significant improvement in magnetic properties was observed compared to magnetic composite materials manufactured under other conditions (those noted with an h in the notes column and those marked with an x), and some of them It almost satisfies the expected value of the volume fraction of a good magnetic material.

In addition, in the example shown in JI & 2 where the volume fraction of the ferromagnetic material was 10%, the preform contracted downward when Alfll hot water was poured, and the predetermined shape could not be obtained.
In addition, in the example shown in 9 I & 50 where the 1 volume ratio is 90%, Aj) W could not be sufficiently penetrated into the preformed body. (Examples with H written in) are compared with the corresponding methods of the present invention (A7-A8, 414-
AI 5.416-A17, bend 18-A19゜44
-Al5. 46-47) Then, only about half of the magnetic properties can be obtained.

In addition, for Pc made by the molten metal impregnation method shown in Table 1 (example of writing KS in the manufacturing method column), the impregnation pressure, that is, the molten metal injection pressure, was 300 to 400 atm, but this was 2 atm in other experiments. It has been confirmed that if the pressure is above, the gas inside the preform will be expelled and the molten Al will be able to sufficiently penetrate into the preform, but this pressure was set to ensure more reliable penetration.

However, it is desirable that the impregnation pressure with the ferromagnetic material be less than the pressure corresponding to the yield stress at the pouring melt temperature of the ferromagnetic material forming the preform. This is because no strain remains inside the material.

Regarding the thermal oxidation applied to the ferromagnetic material prior to impregnation with molten metal, as can be seen in the example shown in I & 6,436,448, 1. The magnetic properties of the composite material are that its volume fraction is 15% and 50%.

Even if it varies to 80%, no singular difference is observed in terms of effectiveness, and the magnetic properties increase as the volume fraction increases.

And grave 30. As can be seen from the examples shown in Ya. 36, 438, even if the form of the ferromagnetic material is changed, the magnetic properties of the magnetic composite material, which is heated and oxidized at a temperature within the range of the conditions of the present invention and has the ferromagnetic material added therein, are still the same. Indicates a high value.

Ninth comparison, instead of heating oxidation in the air, the heat treatment in an inert gas atmosphere (examples where Nt or Ar is entered in the atmosphere) is the same as that of the corresponding method of the present invention. Comparison (A9, 10-m 8.428, 29-4
27) As a result, only about 2/3 of the magnetic properties were obtained.

When we observed the cross sections of representative magnetic composite materials, we found that, for example, the one in the SS S'O example had a ferromagnetic structure as shown in Figure 3a, which is a schematic cross-sectional view of the magnetic composite material. Although oxide 1 (FO) was observed around the material (g), no reaction phase such as Al(6) was observed.

On the other hand, 42 that was heated and oxidized at 210°C in the atmosphere
As shown in FIG. 3bK, which is a schematic cross-sectional view of the magnetic composite material, in the Example 1 and the Example I & 28 which were heat-treated in an inert gas atmosphere, Fe■ and A
The reaction product with l(4), namely the intermetallic compound (AF
), and wear and tear of the ferromagnetic material (g) was observed.

In addition, in the example of flat plate 43 that was heated and oxidized at a temperature of 830°C, the third
As shown in Figure CK, there is an oxide film (F
O) was observed, and no reaction phase with Person 1 (4) was observed; however, the ferromagnetic material 1 (G) was severely damaged by oxidation, and most of the ferromagnetic material had disappeared. found.

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

As mentioned above, the magnetic composite material according to the present invention is added therein to fully exhibit the original magnetic properties of the nine ferromagnetic materials.

〔Effect of the invention〕

The method for manufacturing the magnetic composite material of Act or AlJ alloy according to the present invention involves an interfacial reaction between the ferromagnetic material added therein and the ABt or AlJ alloy, that is, a non-magnetic intermetallic compound. By forming (Aim・Fs) on a ferromagnetic material in advance and suppressing it with a dioxidized film, it is possible to produce a magnetic composite material that has the characteristics of 1Al but still has high magnetic properties. Due to its excellent properties, the magnetic composite material according to the method of the present invention can be used in the field of magnetic material 1 + high performance magnetic shield for practical motor rotors and stators, as well as other electrical products that utilize magnetism. This can greatly contribute to weight reduction.

[Brief explanation of the drawing]

FIG. 1 is a graph showing the relationship between the heating temperature and time of a ferromagnetic material in the atmosphere and the magnetic properties of a magnetic composite material according to the present invention. FIG. 2 is a front sectional view showing a molten metal impregnation apparatus used for producing the magnetic composite material of the present invention. FIG. 3a is a schematic diagram showing a partial cross section of the magnetic composite material. FIG. 3A is a schematic diagram showing a partial cross section of the magnetic composite material. Figure 3C is a schematic diagram showing a partial cross section of the magnetic composite material.
...Plunger.

Claims (1)

[Claims] After preforming powder or fibrous material of a ferromagnetic material made of Fe or Fe alloy, Al or A is added to the preform.
In a method for manufacturing a magnetic composite material containing 15 to 80% by volume of the ferromagnetic material by press-fitting and impregnating a molten metal of L alloy, the ferromagnetic material is preformed,
Alternatively, Al or Al alloy is characterized in that it is then heated and oxidized in the atmosphere at a temperature of 300 to 700°C, and then the molten metal is press-fitted and impregnated into a preform made of the heated and oxidized ferromagnetic material. A method for producing a magnetic composite material.