JP7008391B2 - Manufacturing method of extruded composite material - Google Patents

Description

The present invention relates to an extruded composite material and a method for producing the same.

A composite material having a metal matrix and a dispersoid dispersed in the metal matrix exhibits various properties depending on the content of the dispersoid and the existence form. For example, Fe-dispersed aluminum in which about 8% by mass of Fe (iron) is dispersed in an Al (aluminum) matrix exhibits excellent heat resistance. Further, the Si-dispersed aluminum in which about 15% by mass of Si (silicon) is dispersed in the Al matrix exhibits excellent wear resistance. Further, alumina-dispersed reinforced copper in which alumina is dispersed in a Cu (copper) matrix is excellent in heat resistance and welding resistance, and is suitable as an electrode for performing resistance spot welding.

As a method for producing such a composite material, a method called a melting method for producing an ingot from a molten metal of a metal matrix containing a dispersoid is known. However, the melting method has restrictions on the amount of dispersoids that can be dispersed in the metal matrix, the existence form of the dispersoids, and the like, and may not be able to produce a composite material having desired characteristics. Therefore, a method called a powder metallurgy method, in which the amount and existence form of the dispersoid that can be dispersed in the metal matrix can be selected from a wider range than the melting method, may be adopted (Non-Patent Document 1). ).

Kazuhisa Shibue, "Quenched Solidified Aluminum Alloy", Light Metals, Japan Institute of Light Metals, 1989, Vol. 39, No. 11, p. 850-862

In the powder metallurgy method, the powder of the metal matrix and the powder of the dispersoid are prepared separately and mixed, so that the material, amount and existence form of the dispersoid that can be dispersed in the metal matrix can be freely selected. can. Therefore, the performance of the composite material can be easily improved as compared with the melting method.

However, the metal matrix and dispersoid powder used in the powder metallurgy method need to be produced by the atomizing method. It is difficult to increase the yield of powder by the atomizing method. Therefore, the powder metallurgy method tends to increase the material cost as compared with the melting method.

Further, in the powder metallurgy method, after mixing a mixed powder of a metal matrix and a dispersoid, a green compact is formed by a method such as hot pressing or extrusion, and further processed by forging, extrusion, rolling or the like. It is necessary to crush the voids inside the sintered body. Therefore, the powder metallurgy method has a larger number of steps than the melting method, and the manufacturing cost tends to increase.

As described above, the composite material produced by the powder metallurgy method has excellent performance as compared with the composite material produced by the melting method, but tends to increase the material cost and the manufacturing cost.

The present invention has been made in view of this background, and is an extruded composite material having excellent performance equal to or higher than that of a composite material obtained by a powder metallurgy method, and an extruded composite material capable of inexpensively producing the extruded composite material. It is intended to provide a method for manufacturing a material.

One aspect of the present invention is a method for producing an extruded composite material having a metal matrix and a dispersoid dispersed in the metal matrix.
The die is pressed against the matrix block to be the metal matrix to rotate the die, and at the same time, the material to be dispersed to be the dispersoid is supplied to the matrix block to cause the matrix block to be plastically flowed to be dispersed. The material is dispersed in the matrix mass and
Extrude the matrix mass from the die to make the extruded composite.
It is in the method of manufacturing an extruded composite material.

In the method for producing an extruded composite material, the material to be dispersed can be dispersed in the matrix mass by plastically flowing the matrix mass by rotating the die. As the matrix mass, for example, an ingot produced by a melting method or the like can be used, so that it is possible to avoid the use of relatively expensive metal matrix powder. Further, in the above-mentioned manufacturing method, when the material to be dispersed is involved in the plastic flow of the matrix mass, the material to be dispersed can be mechanically crushed. Therefore, as the material to be dispersed, not only the powder produced by the atomizing method but also various forms of the material to be dispersed such as a plate material, a bar material, and a foil material can be used.

As described above, in the above-mentioned manufacturing method, it is possible to use a matrix mass or the like, which is much cheaper than a powder such as a metal matrix produced by an atomizing method. Therefore, the manufacturing method can reduce the material cost as compared with the conventional powder metallurgy method.

Further, in the above-mentioned manufacturing method, an extruded composite material can be produced by dispersing the material to be dispersed in the matrix mass by rotating the die and then extruding the matrix mass from the die. Therefore, the number of steps can be reduced and the manufacturing cost can be reduced as compared with the powder metallurgy method.

As a result, according to the above-mentioned manufacturing method, the material cost and the manufacturing cost can be reduced as compared with the powder metallurgy method, and the extruded composite material can be manufactured at low cost.

Further, in the above-mentioned manufacturing method, the material to be dispersed can be dispersed in the matrix mass by mechanically stirring the matrix mass and the material to be dispersed, so that the material, amount and existence form of the dispersoid in the metal matrix can be dispersed. Can be freely selected. Therefore, according to the above-mentioned manufacturing method, it is possible to produce an extruded composite material having excellent performance equal to or higher than that of the composite material obtained by the powder metallurgy method.

As described above, according to the above-mentioned manufacturing method, an extruded composite material having excellent performance can be manufactured at low cost.

FIG. 3 is a partial cross-sectional view showing a state in which a matrix mass is inserted into a container in the method for manufacturing an extruded composite material of Reference Example 1 . FIG. 3 is a partial cross-sectional view showing a state in which a matrix mass is agitated in the method for producing an extruded composite material of Reference Example 1 . FIG. 3 is a partial cross-sectional view showing a state in which a matrix mass having been stirred is extruded in the method for producing an extruded composite material of Reference Example 1 . It is a top view of the inner side surface of the die in the reference example 1. FIG. FIG. 3 is a partial cross-sectional view showing a state in which a matrix mass is agitated in the method for producing an extruded composite material of Reference Example 2 . FIG. 3 is a partial cross-sectional view showing a state in which an oxide is formed on the surface of a matrix mass in the method for producing an extruded composite material of Reference Example 2 . It is a partial cross-sectional view which shows the state which the matrix mass is agitated while supplying the material to be dispersed in the manufacturing method of the extruded composite material of Example 1. FIG.

In the method for producing an extruded composite material, for example, an ingot or a billet produced by a melting method can be used as the matrix mass to be a metal matrix. The material of the matrix block is not particularly limited, but the matrix block may be made of, for example, aluminum, an aluminum alloy, copper, a copper alloy, or the like.

The material to be dispersed as the dispersoid can take various forms such as a plate material, a foil material, a bar material, a wire material, a granular material, and a powder. Further, for example, the outer surface of the matrix mass may be oxidized to form an oxide of the matrix mass in advance, and this oxide may be used as a material to be dispersed.

The arrangement of the material to be dispersed is not particularly limited as long as it can be involved in the plastic flow of the matrix mass and the material to be dispersed can be dispersed in the matrix mass. For example, the matrix mass may be stirred with the material to be dispersed placed on the outer surface of the matrix mass, or the matrix mass may be stirred while the material to be dispersed is supplied to the surface of the matrix mass.

The material of the material to be dispersed is not particularly limited, but the material to be dispersed may be, for example, a simple substance such as Si (silicon), Fe (iron), Cr (chromium), Zr (zirconium), P (phosphorus), or a metal oxide. It may be composed of ceramics such as metal carbides and metal nitrides.

In the above-mentioned manufacturing method, the die is pressed against the matrix mass and rotated in a state where the matrix mass and the material to be dispersed are in contact with each other. When pressing the dice against the matrix block, the rotated dice may be pressed against the matrix, or the dice may be rotated after the dice are pressed against the matrix. Further, the temperature of the matrix block when the dice are pressed may be room temperature, or may be higher than room temperature by preheating.

By pressing the die against the matrix block and rotating it, the matrix block can be plastically flowed. At this time, when the planned dispersion material is powder, the planned dispersion material can be dispersed in the matrix mass by involving the planned dispersion material in the plastic flow of the matrix mass. Further, when the material to be dispersed is other than powder, that is, a plate material or the like, the material to be dispersed can be crushed into particles by involving the material to be dispersed in the plastic flow of the matrix mass. Therefore, even in this case, the material to be dispersed can be dispersed in the matrix mass.

An extruded composite material can be produced by dispersing the material to be dispersed in the matrix mass by rotating the die and then extruding the matrix mass from the die. Extrusion of the matrix mass may be performed by indirect extrusion, that is, a method of pushing the die into the matrix block with the matrix block fixed, or direct extrusion, that is, a method of pushing the matrix block into the die. Further, the extrusion of the matrix mass may be performed in parallel with the stirring of the matrix mass, or may be performed after the stirring of the matrix mass is completed.

Further, in the above-mentioned manufacturing method, the die is pressed against the matrix mass and the die is rotated to cause the matrix mass to plastically flow and generate heat.
Then, by separating the die from the matrix mass, the surface of the matrix mass is oxidized to form an oxide as a material to be dispersed.
Press the dice back against the matrix block and
Oxides can also be dispersed in the matrix mass by rotating the die to plastically flow the matrix mass.

In this case, heat treatment or the like for oxidizing the surface of the matrix mass can be omitted. Therefore, the manufacturing process of the extruded composite material can be simplified.

The extruded composite material obtained as described above may be used as it is, or may be further subjected to molding processes such as cutting, forging, bending, pressing, and cutting to form a desired shape.

According to the above-mentioned production method, the combination of the metal matrix and the dispersoid can be freely selected. For example, when aluminum or an aluminum alloy is used as the matrix mass and Fe or Fe alloy is used as the planned dispersion material, Fe-dispersed aluminum having excellent heat resistance can be produced as the extruded composite material. Further, when aluminum or an aluminum alloy is used as the matrix block and Si or a Si alloy is used as the material to be dispersed, Si-dispersed aluminum exhibiting excellent wear resistance can be produced as the extruded composite material.

Further, a Cu-based alloy containing Al: 0.05 to 1.2% by mass may be used as the matrix mass, and a Cu oxide may be used as the material to be dispersed. In this case, an extruded composite material in which Cu oxide as a dispersoid is dispersed in a Cu-based alloy as a metal matrix can be produced.

The extruded composite material thus obtained can be used as a preform of alumina-dispersed reinforced copper. That is, by heating this extruded composite material to 700 to 1050 ° C., oxygen in the Cu oxide can be diffused into the metal matrix, and Al in the metal matrix can be internally oxidized. As a result, it is possible to obtain alumina-dispersed reinforced copper in which alumina is dispersed in a Cu-based alloy.

When the preform of alumina-dispersed reinforced copper is produced by the above method, the mass of Cu oxide is preferably 3.5 to 9.5 times the mass of Al in the matrix mass. In this case, the balance between the amount of Al in the matrix mass and the amount of oxygen in the Cu oxide can be set within an appropriate range, and Al can be sufficiently oxidized while suppressing the oxidation of the metal matrix during internal oxidation. can. As a result, the heat resistance and welding resistance of the alumina-dispersed reinforced copper can be further improved.

As described above, the alumina-dispersed reinforced copper obtained by internally oxidizing the preform has, for example, a metal matrix made of a Cu-based alloy containing Al: 0.30% by mass or less and 0 dispersed in the metal matrix. An extruded composite containing a dispersoid of .050 to 2.0% by weight of alumina. Further, by making the preform structure a two-layer structure of an outer skin portion made of a metal matrix and a composite material portion arranged inside the outer skin portion, the extruded composite material after internal oxidation is made of alumina-dispersed reinforced copper. It is also possible to have a two-layer structure including a composite material portion and an outer skin portion made of a Cu-based alloy and covering the composite material portion.

Alumina-dispersed reinforced copper obtained by internal oxidation of the preform can easily refine alumina as a dispersoid. Therefore, the performance such as heat resistance and welding resistance of the alumina-dispersed reinforced copper can be further improved. The alumina dispersion reinforced copper obtained by such a method is suitable as a material for electrodes for resistance spot welding and lead wires of electronic devices, for example.

( Reference example 1 )
A reference example of the method for producing the extruded composite material will be described with reference to FIGS. 1 to 4. In the production method of this example, as shown in FIG. 1, a matrix mass 20 whose surface is covered with the material to be dispersed 30 is produced. Next, as shown in FIG. 2, the die 41 is pressed against the matrix block 20 in a state where the matrix block 20 to be the metal matrix 2 and the material to be dispersed 30 to be the dispersoid 3 are in contact with each other to rotate the die 41 ( Arrow 410). Then, the matrix mass 20 is plastically flowed by the rotation of the die 41, and the material 30 to be dispersed is dispersed in the matrix mass 20. Then, by extruding the matrix mass 20 from the die 41 as shown in FIG. 3, an extruded composite material 1 having the metal matrix 2 and the dispersoid 3 dispersed in the metal matrix 2 can be produced.

Hereinafter, the manufacturing method of this example will be described in more detail. The matrix mass 20 of this example is a billet containing Al: 0.30% by mass, the balance having a chemical component composed of Cu and unavoidable impurities, and exhibiting a columnar shape having a diameter of 90 mm and a length of 100 mm. The matrix ingot 20 was made by preparing an ingot made of the Cu-based alloy and having a columnar shape having a diameter of 95 mm and a length of 180 mm by a melting method, and then surface-cutting the surface of the ingot.

The matrix mass 20 thus obtained was held at a temperature of 800 ° C. for 2 hours in an atmospheric atmosphere for preheating. By this preheating, as shown in FIG. 1, a Cu oxide film 31 as a material to be dispersed 30 was formed on the surface of the matrix mass 20. The mass of the Cu oxide film 31 was 3.5 to 9.5 times the mass of Al in the matrix mass 20.

FIG. 1 shows a main part of the hot extruder 4 used for manufacturing the extruded composite material 1 in this example. The hot extruder 4 has a die 41 for stirring and extruding the matrix block 20, a die holder 42 for holding the die, and a container 43 for holding the matrix block 20.

As shown in FIG. 4, the die 41 has an opening 411 for extruding the matrix mass 20. The opening 411 in the die 41 of this example has a circular shape with a diameter of 25 mm. The inner surface 412 of the die 41, that is, the surface pressed against the matrix mass 20, is inclined so as to project rearward as it goes outward in the radial direction, as shown in FIG. Further, a plurality of grooves 413 are provided on the inner side surface 412 of the die 41. The groove 413 of this example has a spiral shape from the opening 411 toward the outer peripheral edge of the inner side surface 412 while turning clockwise.

As shown in FIG. 1, the die holder 42 is arranged in front of the container 43. The rear end of the die holder 42, that is, the end on the container 43 side, is configured to hold the die 41. Further, the die holder 42 is configured to be able to move to the container 43 side while rotating the die 41.

In this example, as shown in FIG. 1, after inserting the matrix mass 20 having the Cu oxide film 31 on the surface into the container 43, the die holder 42 is rotated and moved to the rear, that is, to the container 43 side (). See arrow 421). Then, the die 41 held by the die holder 42 was pressed against the matrix block 20 while rotating.

The rotation speed of the die 41 can be appropriately set from the range of, for example, 500 to 5000 rpm. The rotation speed of the die 41 of this example was 1500 rpm, and the rotation direction of the die holder 42 was set to be clockwise when viewed from the inner side surface 412 side of the die 41 (see FIGS. 2 and 4, arrow 410). The pressing load of the die 41 was set to 10 kN.

By pressing the die 41 against the matrix mass 20 while rotating the die 41 in this way, as shown in FIG. 2, the entire matrix mass 20 was plastically flowed. At the contact portion between the matrix mass 20 and the die 41, the matrix mass 20 was guided toward the rotation center axis side along the groove 413, and plastic flow was generated from the outer surface of the matrix mass 20 toward the inside. Further, the Cu oxide film 31 as the material to be dispersed 30 was crushed by being involved in this plastic flow. As a result of the above, the Cu oxide particles 310 were dispersed throughout the matrix mass 20.

After sufficiently stirring the matrix mass 20, the pressing load of the die 41 was increased to 100 kN by moving the die holder 42 further backward (see arrow 422) as shown in FIG. As a result, the matrix mass 20 was extruded in front of the die 41 to form the extruded composite material 1.

The extruded composite material 1 obtained by the method of this example has a round bar shape, and has a structure in which the Cu oxide as the dispersoid 3 is dispersed in the entire Cu-based alloy as the metal matrix 2.

The extruded composite material 1 of this example can be used as a preform of alumina-dispersed reinforced copper. When the extruded composite material 1 is made of alumina-dispersed reinforced copper, the extruded composite material 1 may be heated to 700 to 1050 ° C. As a result, oxygen in the Cu oxide can be diffused and Al in the metal matrix 2 can be internally oxidized. As a result, it is possible to produce alumina-dispersed reinforced copper in which alumina as a dispersoid is dispersed in a Cu-based alloy as a metal matrix.

In this example, the extruded composite material 1 was held in vacuum at a temperature of 850 ° C. for 1 hour, and Al in the metal matrix was internally oxidized to obtain alumina-dispersed reinforced copper. After the internal oxidation treatment, the oxide film on the surface of the alumina dispersion reinforced copper was removed, and further drawing was performed to form a round bar having a diameter of 16 mm.

When the chemical components in the alumina dispersion reinforced copper obtained as described above were analyzed, the content of alumina was 0.60% by mass, and the amount of metal Al in the metal matrix was 0.01% by mass. Further, an electrode for resistance spot welding was produced by cutting a round bar of alumina-dispersed reinforced copper to an appropriate length and then forging it. This electrode was attached to a spot welding device, and spot welding was repeatedly performed on a galvanized steel sheet having a plate thickness of 1 mm, and the number of welding times until the electrode became unusable was measured. As a result, the electrode obtained by the method of this example became unusable after about 4000 spot weldings.

The action and effect of this example will be described. In the production method of this example, the Cu oxide particles 310 can be dispersed in the matrix mass 20 by mechanically stirring the matrix mass 20 by rotating the die 41. Therefore, it is possible to avoid the use of relatively expensive metal matrix powder and reduce the material cost as compared with the powder metallurgy method. Further, since the extruded composite material 1 can be produced by extruding the matrix mass 20 after dispersing the Cu oxide particles 310, the number of steps is reduced and the manufacturing cost is reduced as compared with the powder metallurgy method. be able to.

Further, in the manufacturing method of this example, the material 30 to be dispersed can be dispersed in the matrix mass 20 by mechanically stirring the material 30 to be dispersed in the matrix mass 20, so that the material 30 is dispersed in the metal matrix 2. The material, quantity, and existence form of quality 3 can be freely selected. Therefore, according to the production method of this example, the extruded composite material 1 having excellent performance can be produced.

As described above, according to the manufacturing method of this example, the extruded composite material 1 having excellent performance can be manufactured at low cost.

( Reference example 2 )
This example is an example in which a Cu oxide film 31 as a material to be dispersed 30 is formed on the surface of the matrix mass 22 due to the processing heat generated when the matrix mass 22 is stirred. Of the codes used in the reference examples, examples, and comparative examples after this example, the same codes as those used in the existing reference examples are the same as the components in the existing reference examples , etc. unless otherwise specified. Similar components and the like are shown.

In this example, as in Reference Example 1 , a matrix mass 22 was produced by producing an ingot by a melting method and then chamfering the surface of the ingot. The matrix mass 22 of this example is a billet containing Al: 0.60% by mass, the balance having a chemical component composed of Cu and unavoidable impurities, and exhibiting a columnar shape having a diameter of 90 mm and a length of 150 mm.

The matrix mass 22 was kept at a temperature of 800 ° C. for 2 hours in a nitrogen atmosphere for preheating, and then the matrix mass 22 was inserted into the container 43 as shown in FIG. After the preheating was completed, no Cu oxide film was formed on the surface of the matrix mass 22.

Next, the die 41 was pressed against the matrix mass 22 while rotating, and the matrix mass 22 was plastically flowed. The temperature of the matrix mass 22 stirred by the die 41 rises due to the heat generated by processing. In this example, the matrix mass 22 was stirred for 30 seconds. As a result, the outer surface 414 of the die 41, that is, the surface held by the die holder 42, is discolored to black. After that, the die holder 42 was moved forward to pull the die 41 away from the matrix block 22.

When the die 41 is pulled away from the matrix mass 22, the atmosphere comes into contact with the heated matrix mass 22. As a result, as shown in FIG. 6, a Cu oxide film 31 as a material to be dispersed 30 was formed on the surface of the matrix mass 22. Then, the die 41 was pressed against the matrix mass 22 again and rotated to crush the Cu oxide film 31 and stir the matrix mass 22.

In this example, the Cu oxide particles 310 were dispersed in the matrix mass 22 by repeating the cycle of stirring the matrix mass 22 for 30 seconds and then forming the Cu oxide film 31 for 30 seconds five times. .. In each cycle, the rotation speed of the die 41 was set to 3000 rpm.

After repeating the above-mentioned cycle 5 times, the die 41 was pressed against the matrix mass 22 to extrude the matrix mass 22 to obtain an extruded composite material. The obtained extruded composite material was subjected to internal oxidation treatment, removal of an oxide film and extraction processing by the same method as in Reference Example 1 to obtain alumina-dispersed reinforced copper having a diameter of 16 mm and exhibiting a round bar shape. The content of alumina in the alumina dispersion reinforced copper in this example was 1.20% by mass, and the amount of Al in the metal matrix was 0.01% by mass.

After cutting the round bar of alumina dispersion reinforced copper obtained as described above to an appropriate length, an electrode for resistance spot welding was produced by forging. This electrode was attached to a spot welding device, and spot welding was repeatedly performed on a galvanized steel sheet having a plate thickness of 1 mm, and the number of welding times until the electrode became unusable was measured. As a result, the electrode obtained by the method of this example became unusable after about 6000 spot weldings. Others are the same as in Reference Example 1 .

When the material 30 to be dispersed is an oxide of a metal constituting the matrix mass 20, as shown in Reference Example 1 , the material 30 to be dispersed is formed in advance on the surface of the matrix mass 20 by heat treatment such as preheating. Alternatively, as shown in this example, it may be formed by oxidizing the matrix mass 22 in the container 43. According to the method of this example, the heat treatment for oxidizing the surface of the matrix mass 22 can be omitted. Therefore, the manufacturing process of the extruded composite material can be simplified. In addition, the method of this example can exert the same action and effect as that of Reference Example 1 .

(Comparative Example 1)
This example is an example of evaluating the durability of an electrode for resistance spot welding manufactured by a conventional powder metallurgy method. In this example, an electrode for resistance spot welding was produced by forging the alumina dispersion reinforced copper produced by the powder metallurgy method. The mass of alumina contained in the alumina-dispersed reinforced copper was about 0.6% by mass, and the mass of the metal Al was about 0.04% by mass.

The obtained electrode was attached to a spot welder, spot welded repeatedly to a galvanized steel sheet having a plate thickness of 1 mm, and the number of welding times until the electrode became unusable was measured. As a result, the electrode obtained by the method of this example became unusable after about 2000 spot weldings.

From the comparison between Reference Examples 1 and 2 and Comparative Example 1, the extruded composite material produced by the manufacturing methods of Reference Example 1 and Reference Example 2 is used as an electrode for spot welding, and is produced by a conventional powder metallurgy method. It can be understood that the durability in spot welding can be improved as compared with the electrode. Further, it can be easily understood that the extruded composite material can be manufactured at low cost according to the manufacturing methods of Reference Examples 1 and 2.

Further, the alumina-dispersed reinforced copper obtained by the production methods of Reference Examples 1 and 2 has a smaller content of metallic Al than that of Comparative Example 1, that is, the alumina-dispersed reinforced copper obtained by the conventional powder metallurgy method. From these results, it can be easily understood that according to the production methods of Reference Examples 1 and 2, it is possible to produce alumina-dispersed reinforced copper having higher conductivity than the alumina-dispersed reinforced copper by the conventional powder metallurgy method. ..

( Example 1 )
This example is an example of a method for manufacturing an extruded composite material using pure aluminum as a metal matrix. In this example, in the same manner as in Reference Example 1 , a matrix ingot 23 was produced by preparing an ingot by a melting method and then chamfering the surface of the ingot. The matrix block 23 of this example is a billet made of pure aluminum and exhibiting a columnar shape having a diameter of 90 mm and a length of 150 mm.

Further, in this example, as shown in FIG. 7, the die 41 has a circular opening 415 having a diameter of 25 mm, and the container 44 has a supply port 441 for supplying the material to be dispersed 30. A hot extruder 403 was used. The supply port 441 of the container 44 may be provided at any position as long as the material 30 to be dispersed can be involved in the plastic flow of the matrix mass 23 when the matrix mass 23 is agitated. Specifically, the supply port 441 in the container 44 of this example is provided on the wall portion 442 behind the container 44, that is, the wall portion facing the die 41. Further, the supply port 441 has a circular shape with a diameter of 10 mm. The supply port 441 is connected to a tank (not shown) of the planned dispersion material 30 provided outside the container 44 via a planned distribution material supply pipe 443.

In the production method of this example, the matrix mass 23 was held at a temperature of 800 ° C. for 2 hours in a nitrogen atmosphere for preheating, and then the matrix mass 23 was inserted into the container 44. Next, the die 41 held by the die holder 42 was pressed against the matrix mass 23 while rotating, and the matrix mass 23 was plastically flowed. The rotation speed of the die 41 in this example was set to 1500 rpm.

Further, at the same time as stirring the matrix mass 23, the carbon nanotube 32 as the material to be dispersed 30 was supplied into the container 44 from the supply port 441. The carbon nanotubes 32 supplied into the container 44 from the supply port 441 were caught in the plastic flow of the matrix mass 23 and dispersed in the matrix mass 23.

After sufficiently stirring the matrix mass 23, the die 41 was pressed against the matrix mass 23 with a pressing load of 100 kN to extrude the matrix mass 23. From the above, an extruded composite material was obtained.

The extruded composite material obtained by this example has a round bar shape with a diameter of 25 mm, and has a pure aluminum as a metal matrix 2 and carbon nanotubes as a dispersoid 3 dispersed in the metal matrix 2. It became dispersed aluminum. Moreover, when the chemical analysis of the extruded composite material was performed, the composition of the extruded composite material was Al-1% C.

No. 5 test piece specified in JIS Z2241: 2011 was collected from the obtained extruded composite material. This test piece was heated to 230 ° C., and a high-temperature tensile test was performed by a method according to JIS Z2241: 2011. The tensile strength obtained by the high temperature tensile test was 550 MPa.

When the matrix mass 23 and the planned dispersion material 30 are separately prepared and the planned dispersion material 30 is dispersed in the matrix mass 23, the inside of the container 44 is simultaneously stirred by the matrix mass 23 as in the manufacturing method of this example. May be supplied with the material 30 to be dispersed. Further, although not shown in the figure, after inserting the matrix mass 23 and the planned dispersion material 30 into the container 44, the die 41 can be rotated to stir the matrix mass 23 and the planned dispersion material 30. In any case, the planned dispersion material 30 can be dispersed in the matrix mass 23 by plastically flowing the matrix mass 23 in a state where the matrix mass 23 and the planned dispersion material 30 are in contact with each other. As a result, an extruded composite material having excellent performance can be produced at low cost.

(Comparative Example 1)
This example is an example of producing carbon nanotube-dispersed aluminum having a composition of Al-1% C by a powder metallurgy method.

In this example, the pure aluminum powder obtained by the atomizing method and the carbon nanotubes were mixed so that the content of the carbon nanotubes was 1% by mass to prepare a mixed powder. After containing this mixed powder in a metal capsule, the inside of the metal capsule was heated while reducing the pressure to degas the mixed powder.

After degassing was complete, the metal capsules were hot pressed to compress the mixed powder in the capsules to increase bulk density. Then, the green compact of the mixed powder taken out from the metal capsule was hot-extruded to obtain an extruded material of carbon nanotube-dispersed aluminum having a round bar shape with a diameter of 25 mm.

When a high-temperature tensile test was performed using the obtained extruded material by the same method as in Reference Example 1 , the tensile strength of the extruded material was 550 MPa.

From the comparison between Example 1 and Comparative Example 2, it is easy to inexpensively produce an extruded composite material having performance equal to or higher than that of the composite material obtained by the conventional powder metallurgy method, according to the production method of Reference Example 1 . Can be understood.

The embodiment of the extruded composite material and the method for producing the extruded composite material according to the present invention is not limited to the embodiment described above, and the configuration can be appropriately changed as long as the purpose is not impaired.

The combination of the metal matrix and the dispersoid is not limited to the combinations described in Reference Examples 1 and 2 and Example 1 , and can be appropriately changed according to desired characteristics. For example, in Example 1 , the metal matrix is pure aluminum and the dispersoid is carbon nanotubes, but the dispersoid may be changed to Si, ceramics, or the like. Further, the metal matrix can be changed to pure copper or a copper alloy, and the dispersoid can be changed to Cr, Zr, P or the like. Similarly, in Reference Examples 1 and 2, the metal matrix and the dispersoid can be appropriately changed.

Further, in Reference Examples 1 and 2 and Example 1 , although the example in which the stirring and extrusion of the matrix mass are sequentially performed is shown, the stirring and extrusion of the matrix mass may be performed in parallel.

Reference Examples 1 and 2 and Example 1 show an example in which residual heat is applied before inserting the matrix mass into the container, but it is also possible to press the dice into the matrix mass and rotate it without performing preheating. be. Even when preheating is not performed, frictional heat is generated by the rotation of the die, so that the matrix mass can be plastically flowed in the same manner as in the case of preheating.

1 Extruded composite material 2 Metal matrix 20, 22, 23 Matrix mass 3 Dispersant 30 Dispersed material 41 Dice

Claims (4)

A method for producing an extruded composite material having a metal matrix and a dispersoid dispersed in the metal matrix.
The die is pressed against the matrix block to be the metal matrix to rotate the die, and at the same time, the material to be dispersed to be the dispersoid is supplied to the matrix block to cause the matrix block to be plastically flowed to be dispersed. The material is dispersed in the matrix mass and
Extrude the matrix mass from the die to make the extruded composite.
Manufacturing method of extruded composite material. The extruded composite material according to claim 1 , wherein the matrix mass is composed of a Cu-based alloy containing Al: 0.05 to 1.2% by mass, and the material to be dispersed is composed of Cu oxide. Production method. The method for producing an extruded composite material according to claim 2 , wherein the mass of the Cu oxide as the material to be dispersed is 3.5 to 9.5 times the mass of Al in the matrix mass. The method for producing an extruded composite material according to claim 3 , wherein after producing the extruded composite material, the extruded composite material is further heated to 700 to 1050 ° C. to internally oxidize Al in the metal matrix.

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