JP2019116645A - Composite material and its manufacturing method - Google Patents

Abstract

To provide a composite material manufacturing method capable of making a composite material having excellent performance with an inexpensive price.SOLUTION: After arranging a matrix lump 20 in a container 41, a double-acting type tool 42 equipped with a shoulder 43 and a probe 44 is inserted in the container 41. The shoulder 43 is contacted with the matrix lump 20 and the probe 44 is inserted in the matrix lump 20. While the shoulder 43 restrains deformation of the matrix lump 20, the probe 44 is rotated under a condition that the matrix lump 20 and a dispersion scheduled material 30 that becomes a dispersoid 3 are contacted. The rotation of the probe 44 makes the matrix lump 20 perform plastic flow and the dispersion scheduled material 30 is distributed into the matrix lump 20. Then, a composite material 1 having a metal matrix 2 and the dispersoid 3 that is distributed in the metal matrix 2 can be made.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a composite material and a method of manufacturing the same.

  A composite material having a metal matrix and a dispersoid dispersed in the metal matrix exhibits various properties depending on the content and the form of the dispersoid. 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. In addition, Si-dispersed aluminum in which about 15% by mass of Si (silicon) is dispersed in an Al matrix exhibits excellent wear resistance. In addition, alumina dispersion-strengthened 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 of producing such a composite material, there is known a method called a melting method in which an ingot is produced from a molten metal of a metal matrix containing a dispersoid. However, the solution manufacturing method is limited in the amount of dispersoid dispersible in the metal matrix, the existence form of the dispersoid, etc., and it may not be possible to produce a composite material having desired characteristics. Therefore, a method called powder metallurgy may be employed, which can select the amount and the form of dispersoid that can be dispersed in the metal matrix from a wide range as compared with the melt production method (Non-patent Document 1) ).

Shibue Kazuhisa, "Rapid-quenched aluminum alloy", light metal, Japan Institute of Light Metals, 1989, Vol. 39, No. 11, p. 850-862

  In powder metallurgy, it is possible to prepare the powder of the metal matrix and the powder of the dispersoid separately and to freely select the material, the amount, and the form of the dispersoid dispersible in the metal matrix in order to mix them. it can. Therefore, the performance of the composite can be easily improved as compared to the melt process.

  However, the powder of metal matrix and dispersoid used for powder metallurgy needs to be prepared by atomization. The atomization method is difficult to increase the yield of powder. Therefore, the powder metallurgy method tends to increase the material cost compared to the melting method.

  In powder metallurgy, after mixing mixed powder of metal matrix and dispersoid, a green compact is formed by a method such as hot pressing or extrusion, and further processing such as forging, extrusion, or rolling is performed. It is necessary to crush the void inside the sintered body. Therefore, the powder metallurgy method has more processes than the melting method, and the manufacturing cost tends to increase.

  Thus, while the composite produced by the powder metallurgy has superior performance as compared with the composite produced by the melting method, it tends to cause increase in material cost and production cost.

  The present invention has been made in view of the above background, and it is an object of the present invention to provide a composite having excellent performance equal to or higher than that of a composite obtained by powder metallurgy, and a composite capable of inexpensively manufacturing this composite. It is an attempt to provide a way.

One aspect of the present invention is a method of producing a composite material having a metal matrix and a dispersoid dispersed in the metal matrix,
Place a matrix block to be the metal matrix in a container,
Inserting into the container a double acting tool comprising a shoulder having a columnar shape and a probe penetrating the central axis of the shoulder, wherein the shoulder and the probe can be driven separately;
Bringing the shoulder into contact with the matrix mass and inserting the probe into the matrix mass;
The dispersion is performed by causing the matrix mass to plastically flow while rotating the probe in a state in which the matrix mass and the material to be dispersed which is the dispersoid are in contact while constraining the deformation of the matrix mass by the shoulder. Dispersing scheduled material into the matrix mass,
It is in the manufacturing method of the composite material.

  In the method of manufacturing the composite material, the material to be dispersed can be dispersed in the matrix mass by mechanically stirring the matrix mass by rotation of the probe. As a matrix mass, for example, an ingot produced by a melting method or the like can be used, so that the use of a relatively expensive metal matrix powder can be avoided. Further, according to the 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, it is possible to use, as the material to be dispersed, not only the powder produced by the atomizing method, but also to-be-dispersed materials of various forms such as a plate, a bar, and a foil material.

  As described above, in the above-described manufacturing method, a matrix block or the like which is much cheaper than the powder such as a metal matrix formed by the atomization method can be used. Therefore, the manufacturing method can reduce the material cost as compared to the conventional powder metallurgy method.

  Further, in the above-mentioned manufacturing method, since the matrix mass is mechanically stirred by rotation of the probe while the deformation of the matrix is restrained by the shoulders, defects such as voids are hardly formed inside the composite material after the stirring is completed. Therefore, it is possible to omit the rolling and the like for crushing the defects inside the composite material as in the conventional powder metallurgy method. Therefore, the manufacturing method can reduce the number of steps and the manufacturing cost as compared to powder metallurgy.

  Therefore, according to the said manufacturing method, compared with a powder metallurgy method, material cost and manufacturing cost can be reduced, and a composite material can be produced cheaply.

  Further, since the production method can disperse the material to be dispersed in the matrix mass by mechanically stirring the matrix mass and the material to be dispersed, the material and amount of the dispersoid in the metal matrix, and the existence form Can be chosen freely. Furthermore, in the above-mentioned manufacturing method, the effect of making the material to be dispersed finely can be expected by crushing the material to be dispersed when mechanically stirring the matrix mass and the material to be dispersed. Therefore, the above-mentioned production method can produce a composite containing fine dispersoids as compared with the composite by the conventional powder metallurgy method.

  As a result, according to the manufacturing method, it is possible to produce a composite having the same or better performance as the composite obtained by the powder metallurgy method.

  As mentioned above, according to the said manufacturing method, the composite material which has the outstanding performance can be produced at low cost.

In the manufacturing method of the composite material of Example 1, it is a partial cross section figure which shows the state which made the double acting tool contact | abut to a matrix lump. In the manufacturing method of the composite material of Example 1, it is a partial cross section figure which shows the state which is stirring the matrix lump. In the manufacturing method of the composite material of Example 1, it is a partial cross section figure which shows the state which extracted the double acting tool from the matrix lump. 5 is a cross-sectional view showing the main parts of the electrode tip obtained by the manufacturing method of Example 1. FIG. In the manufacturing method of the composite material of Example 2, it is a partial cross section figure which shows the state which made the double-acting type | mold tool contact | abut to the matrix lump provided with the dispersion plan material in a back end part. In the manufacturing method of the composite material of Example 2, it is a partial cross section figure which shows the state which is stirring the matrix lump. In the manufacturing method of the composite material of Example 2, it is a partial cross section figure which shows the state in the middle of extracting the double acting tool from the matrix block. FIG. 7 is a cross-sectional view showing the main parts of the electrode tip obtained by the manufacturing method of Example 2. In the manufacturing method of the composite material of Example 3, it is a partial cross section figure which shows the state which is stirring the matrix lump. In the manufacturing method of the composite material of Example 3, it is a partial cross section figure which shows the state which is extruding a matrix lump.

  In the method of manufacturing the composite material, for example, an ingot or billet produced by a melting method can be used as a 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, which is a dispersoid, may take various forms such as a plate, a foil, a bar, a wire, a granular body, and a powder. Alternatively, 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 the material to be dispersed can be dispersed in the matrix mass by being involved in the plastic flow of the matrix mass. For example, the matrix mass may be stirred in a state where the material to be dispersed is disposed on the outer surface of the matrix mass, or the matrix mass may be agitated in a state where the material to be dispersed is disposed inside the holes provided in advance in the matrix mass It is also good. Furthermore, it is also possible to stir the matrix mass while supplying the material to be dispersed, such as by supplying the material to be dispersed from the probe as the probe rotates.

  The material of the material to be dispersed is not particularly limited, but the material to be dispersed is, for example, a simple substance such as Si (silicon), Fe (iron), Cr (chromium), Zr (zirconium), P (phosphorus), metal oxide, You may be comprised from ceramics, such as metal carbide and metal nitride.

  In the above manufacturing method, first, a matrix block is placed in a container. The shape of the container is not particularly limited, but, for example, when upsetting is performed simultaneously with the stirring of the matrix mass, the shape of the internal space of the container becomes the shape of the composite after being upset.

  In addition, the container may have a die attachment port for attaching a die. In this case, the die can be attached to the die attachment port after the stirring of the matrix block is completed, and the matrix block can be extruded from the die. In addition, what is necessary is just to obstruct | occlude a dice | dies attachment port with a closure member, while stirring a matrix lump.

  After placing the matrix mass in the container, insert a double acting tool with a shoulder and a probe in the container. The double acting tool is configured to drive the shoulder and the probe separately. The probe is configured to move in the back and forth direction and to be rotatable around its central axis. In addition, the shoulder is configured to be movable in the front-rear direction. The shoulder may be configured to be able to rotate about its central axis in addition to movement in the back and forth direction. As this type of double-acting tool, for example, a double-acting tool for friction stir welding can be used.

  After the double acting tool is inserted into the container, the shoulder is brought into contact with the matrix mass and the probe is inserted into the matrix mass. The timing at which the probe is inserted into the matrix mass may be simultaneous with or different from the timing at which the shoulder abuts on the matrix mass. Further, the temperature of the matrix mass at this time may be room temperature or may be higher than room temperature by preheating.

  Next, while constraining the deformation of the matrix mass by the shoulder, the probe is rotated in a state in which the matrix mass and the material to be dispersed are in contact to cause the matrix mass to plastically flow. At this time, when the material to be dispersed is powder, the material to be dispersed can be dispersed in the matrix mass by incorporating the material to be dispersed into the plastic flow of the matrix mass. When the material to be dispersed is other than powder, that is, a plate or the like, the material to be dispersed can be crushed into particles by incorporating the material to be dispersed into the plastic flow of the matrix block. Therefore, also in this case, the material to be dispersed can be dispersed in the matrix mass.

  The range in which plastic flow occurs in the matrix mass can be controlled, for example, by the thickness of the matrix mass, that is, the thickness of the matrix mass in the radial direction of the probe, the number of rotations of the probe, the shape of the probe, and the like. For example, if the thickness of the matrix mass is relatively thin, the entire matrix mass can be plastically flowed by rotation of the probe. In this case, the material to be dispersed can be dispersed throughout the matrix mass. As a result, it is possible to obtain a composite in which the dispersoid is dispersed throughout the metal matrix.

  Also, for example, when the thickness of the probe is relatively large, it is possible to plastically flow only the periphery of the probe in the matrix mass by the rotation of the probe. In this case, it is possible to form a composite material including a stirring portion provided with a metal matrix and a dispersoid, and a non-stirring portion formed of a metal matrix and connected to the stirring portion. In this case, since the stirring portion and the non-stirring portion are integrally formed, when the composite material is subjected to forming processing such as forging, bending, or pressing, peeling of the outer skin from the stirring portion is effectively performed. It can be suppressed.

  When the material to be dispersed is dispersed in the matrix mass by the rotation of the probe and then the probe is removed from the matrix mass, recesses corresponding to the shape of the probe are formed in the matrix mass. If there is no problem even if the concave portion remains in the final product, preparation of the composite can be completed with the concave portion remaining.

  Also, by pushing the shoulder into the matrix mass, the probe can be removed while filling the recess back. In this case, a composite having no recess can be obtained.

  The composite material obtained by the above may be used as it is, or may be formed into a desired shape by appropriately performing forming processing such as cutting, forging, bending, pressing, cutting and the like.

  The shape of the composite material obtained by the manufacturing method is the shape of a space surrounded by the container and the double acting tool. Therefore, by setting the shape of the inner space of the container to the shape of the final product or a shape close to this, it is possible to perform so-called near net shape forming to make the composite material the shape of the final product or a shape close thereto.

  When the shape of the composite material is the shape of the final product, it is not necessary to process the composite material into the shape of the final product. In addition, when the shape of the composite material is close to the shape of the final product, processing for forming the composite material into the shape of the final product is performed, for example, as compared to the case where the plate and rod are subjected to forming processing. It can be greatly shortened. Therefore, by performing near net shape molding by the above-mentioned manufacturing method, the processing cost can be further reduced when producing the final product from the composite material.

  Alternatively, after dispersing the material to be dispersed in the matrix mass by rotating the probe, a die may be attached to the container and the composite material may be manufactured by extruding the matrix mass from the die.

  According to the manufacturing method, the combination of the metal matrix and the dispersoid can be freely selected. For example, when aluminum or an aluminum alloy is adopted as a matrix mass and Fe or an Fe alloy is adopted as a material to be dispersed, it is possible to produce Fe-dispersed aluminum having excellent heat resistance as a composite material. When aluminum or an aluminum alloy is adopted as a matrix mass and Si or a Si alloy is adopted as a material to be dispersed, Si-dispersed aluminum exhibiting excellent wear resistance can be produced as a composite material.

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

  The composite thus obtained can be used as a preform of alumina dispersion strengthened copper. That is, by heating this 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, alumina dispersion-strengthened copper in which alumina is dispersed in a Cu-based alloy can be obtained.

  When preparing a preform of alumina dispersion-strengthened copper by the above-mentioned 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 should be in a proper range to sufficiently oxidize Al while suppressing the oxidation of the metal matrix during internal oxidation. it can. As a result, the heat resistance and welding resistance of alumina dispersion strengthened copper can be further improved.

  As described above, the alumina dispersion-strengthened copper obtained by internally oxidizing the preform is, 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. And a dispersoid composed of 50 to 2.0% by mass of alumina. In addition, by making the structure of the preform into a two-layer structure of an outer skin portion made of a metal matrix and a stirring portion disposed inside the outer skin portion, the composite material after internal oxidation is made of an alumina dispersion reinforced copper stirring portion It is also possible to provide a two-layer structure provided with an outer shell portion made of a Cu-based alloy and covering the stirring portion.

  The alumina dispersion-strengthened copper obtained by internal oxidation of the preform can easily refine the alumina as a dispersoid. Therefore, the performance such as heat resistance and adhesion resistance of alumina dispersion strengthened copper can be further improved. The alumina dispersion-strengthened copper obtained by this method is suitable, for example, as a material for an electrode for resistance spot welding or a lead wire of an electronic device.

Example 1
An embodiment of the method of manufacturing the composite material will be described with reference to FIGS. 1 to 4. In the manufacturing method of this embodiment, as shown in FIG. 1, after the matrix block 20 to be the metal matrix 2 is disposed in the container 41, the double acting tool 42 is inserted into the container 41. The double acting tool 42 has a column-shaped shoulder 43 and a probe 44 penetrating the central axis of the shoulder 43, and the shoulder 43 and the probe 44 can be separately driven.

  Then, the shoulder 43 is brought into contact with the matrix mass 20 and the probe 44 is inserted into the matrix mass 20. Then, as shown in FIG. 2, while constraining the deformation of the matrix mass 20 by the shoulder 43, the probe 44 is rotated in a state where the matrix mass 20 and the material to be dispersed 30 to be the dispersoid 3 are in contact (arrow 441) . As a result, the matrix mass 20 is made to flow plastically by the rotation of the probe 44, and the material to be dispersed 30 is dispersed in the matrix mass 20. Thus, the composite material 1 having the metal matrix 2 and the dispersoid 3 dispersed in the metal matrix 2 can be manufactured.

  Hereinafter, the manufacturing method of this example will be described in more detail. The matrix block 20 of this example is a small piece of a Cu-based alloy containing 0.30% by mass of Al, with the balance being Cu and unavoidable impurities. The matrix block 20 has a round bar shape with a diameter of 19 mm and a length of 30 mm, and can be produced by extruding the ingot produced by the melting method.

  In this example, the matrix block 20 was preheated by holding it at a temperature of 800 ° C. for 2 hours in the air. By this preheating, as shown in FIG. 1, a film of Cu oxide 31 as the material to be dispersed 30 was formed on the surface of the matrix block 20. The thickness of the film of Cu oxide 31 was about 100 μm, and the mass was 3.5 to 9.5 times the mass of Al in the matrix mass 20.

  The composite material 1 was produced by the following method using the matrix mass 20 obtained in this manner. The principal part of the manufacturing apparatus 4 used for preparation of the composite material 1 in this example is shown in FIG. The manufacturing device 4 comprises a container 41 for holding the matrix mass 20 and a double acting tool 42 with a shoulder 43 and a probe 44.

  The double acting tool 42 is disposed behind the container 41. The shoulder 43 of the double acting tool 42 is configured to be movable in the front-rear direction, that is, in both directions approaching the container 41 and away from the container 41. The shoulder 43 in this example has a cylindrical shape with an outer diameter of 19 mm.

  The probe 44 of the double acting tool 42 is configured to be able to rotate about its central axis, as indicated by an arrow 441 (see FIG. 2). Further, the probe 44 is configured to be movable in the front-rear direction independently of the shoulder 43. The probe 44 of this example has a cylindrical shape with an outer diameter of 10 mm, and has a spiral groove (not shown) for stirring the matrix mass 20 on the outer surface.

  In the manufacturing method of this example, first, the matrix block 20 was placed in the container 41 of the manufacturing apparatus 4. Next, as shown in FIG. 1, the double acting tool 42 was moved forward to bring the shoulder 43 into contact with the matrix mass 20 and press the tip 442 of the probe 44 against the material 30 to be dispersed.

  After bringing the tip 442 of the probe 44 into contact with the material 30 to be dispersed, the probe 44 is further pushed forward while rotating the probe 44 as shown by the arrow 441 to extend to the inside of the matrix mass 20 as shown in FIG. The tip 442 was inserted. At this time, the shoulder 43 was retracted (arrow 431) to balance the volume of the matrix mass 20 pushed out by the probe 44, and a space for inserting the probe 44 was secured. In addition, the rotational speed of the probe 44 can be suitably set from the range of 500-5000 rpm, for example. The rotation speed of the probe of this example was 1500 rpm.

  In the present example, the rotation of the probe 44 causes the entire matrix mass 20 to be agitated, resulting in plastic flow. At this time, the film of the Cu oxide 31 as the material to be dispersed 30 was crushed by the rotation of the probe 44 and the plastic flow of the matrix block 20, and the particles 310 of the Cu oxide 31 were formed. Further, a shoulder 43 is in contact with the periphery of a portion of the matrix mass 20 in contact with the probe 44. Therefore, the matrix mass 20 was confined within the space surrounded by the double acting tool 42 and the container 41, and no leakage of material to the outside of the space occurred.

  As a result of the above, as the probe 44 advances, the particles 310 of the Cu oxide 31 as the material to be dispersed 30 are dispersed in the matrix mass 20.

  When the tip 442 of the probe 44 reached a depth of 20 mm from the rear end of the matrix block 20, the forward movement of the probe 44 was stopped. In this state, the probe 44 was rotated for a while, and the whole matrix mass 20 was sufficiently stirred. Thereafter, as shown in FIG. 3, the entire double acting tool 42 was retracted, and the probe 44 was pulled out of the matrix block 20.

  The composite material 1 obtained as described above has a round bar-like shape, and as shown in FIG. 3, has a recess 11 corresponding to the shape of the probe 44 on the central axis thereof. In addition, the composite material 1 has a structure in which particles 310 of the Cu oxide 31 as the dispersoid 3 are dispersed in the entire Cu-based alloy as the metal matrix 2.

  The composite material 1 of this example can be used as a preform of alumina dispersion-strengthened copper. In the case where the composite material 1 is made of alumina dispersion-strengthened copper, the composite material 1 may be heated to 700 to 1050 ° C. Thereby, oxygen in the Cu oxide can be diffused, and Al in the metal matrix 2 can be internally oxidized. As a result, as shown in FIG. 4, it is possible to produce alumina dispersion-strengthened copper in which alumina 32 as dispersoid 3 is dispersed in a Cu-based alloy as metal matrix 2.

  In this example, the composite material 1 was held at a temperature of 850 ° C. in vacuum for 1 hour to internally oxidize Al in the metal matrix 2 to obtain alumina dispersion strengthened copper. Analysis of the chemical components of the alumina dispersion-strengthened copper revealed that the content of alumina 32 was 0.60% by mass, and the amount of metal Al in the metal matrix 2 was 0.01% by mass.

  After the internal oxidation treatment was performed, the front end portion of the composite material 1 was subjected to cutting to produce an electrode tip 12 for a resistance spot electrode shown in FIG. The tip portion of the electrode tip 12 has a so-called dome radius type including a tip surface 13 having a circular shape with a diameter of 6 mm and a dome surface 15 connecting the tip surface 13 and the side peripheral surface 14. The dome surface 15 has an arc-like contour in the longitudinal cross section of the electrode tip 12. Moreover, the curvature radius of the dome surface 15 in the said cross section is 40 mm.

  The electrode tip 12 was attached to a spot welding apparatus, and spot welding was repeatedly performed on a galvanized steel sheet having a thickness of 1 mm, and the number of times of welding until the electrode tip 12 became unusable was measured. As a result, the electrode tip 12 obtained by the method of this example became unusable after about 4000 spot weldings.

  The operation and effect of this example will be described. In the manufacturing method of this example, the material to be dispersed 30 can be dispersed in the matrix mass 20 by mechanically stirring the matrix mass 20 by the rotation of the probe 44. Therefore, the use of relatively expensive powder of metal matrix 2 can be avoided, and the material cost can be reduced compared to powder metallurgy. Moreover, since the process for crushing the space inside the sintered body, such as the conventional powder metallurgy method, can be omitted after the stirring of the matrix mass 20, the number of processes can be increased compared to the powder metallurgy method. The cost can be reduced and the manufacturing cost can be reduced.

  Furthermore, according to the manufacturing method of this example, since the material to be dispersed 30 can be dispersed in the matrix mass 20 by mechanically stirring the matrix mass 20 and the material to be dispersed 30, dispersion in the metal matrix 2 is achieved. The quality 3 material, amount, and form of presence can be freely selected. Therefore, according to the manufacturing method of this example, the composite material 1 having excellent performance can be manufactured.

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

  Moreover, the manufacturing method of this example can make the shape of the composite material 1 a shape close to the electrode tip 12 for resistance spot welding which is a final product. That is, the manufacturing method of this example can perform so-called near net shape molding. Therefore, the electrode tip 12 can be easily manufactured by subjecting the tip portion of the composite material 1 or the like to cutting. Therefore, the manufacturing method of this example can greatly shorten the processing for forming the composite into the shape of the final product, and can further reduce the processing cost when producing the final product from the composite.

(Example 2)
This example is an example of a method of extracting the probe 44 from the matrix block 20 while filling back the recess formed in the matrix block 20. Note that among the reference numerals used in the examples after the present embodiment, the same reference numerals as those used in the previous examples indicate the same constituent elements as the constituent elements in the previous examples unless otherwise described.

  In this example, after the matrix block 20 is produced by the same method as in Example 1, one end face 21 of the matrix block 20 is heated by a gas burner, and as shown in FIG. A film of Cu oxide 31 as 30 was formed. The thickness of the film of Cu oxide 31 was 100 μm.

  The matrix block 20 was placed in the container 41 so that the end face 21 provided with the film of the Cu oxide 31 faced the back, that is, the side where the probe 44 was inserted. Thereafter, the matrix block 20 was stirred in the same manner as in Example 1 except that the insertion depth of the probe 44 was changed to 15 mm.

  In this example, as shown in FIG. 6, only the peripheral portion of the probe 44 in the matrix mass 20 is agitated, and plastic flow occurs in the front portion of the matrix mass 20, that is, the portion where the probe 44 is not inserted. It was not. Therefore, the particles 310 of the Cu oxide 31 were dispersed only in the rear part of the matrix block 20, that is, in the peripheral part of the probe 44.

  After agitation of the matrix mass 20 was completed, the probe 44 was withdrawn from the matrix mass 20 (arrow 443). At this time, as shown in FIG. 7, the shoulder 43 was advanced by an amount corresponding to the volume of the probe 44 extracted from the matrix block 20 (arrow 432). Thus, the probe 44 was removed while the recess 11 formed by the probe 44 was being refilled.

  Thus, a composite material 102 having a cylindrical shape is obtained. As shown in FIG. 8, the composite material 102 of this example includes the metal matrix 2 and the stirring portion 16 including the Cu-based alloy as the metal matrix 2, the particles 310 of the Cu oxide 31 as the dispersoid 3. It has a non-stirring portion 17 connected to the stirring portion 16. Specifically, the stirring portion 16 is formed on one end side of the composite material 102 in the longitudinal direction, and the non-stirring portion 17 is formed on the other end side.

  Thereafter, the composite material 102 was subjected to internal oxidation treatment in the same manner as in Example 1, and the stirring portion 16 was made of alumina dispersion-strengthened copper. When the chemical component of the stirring part 16 after internal oxidation processing was analyzed, content of the alumina in the stirring part 16 was 0.60 mass%, and content of metal Al was 0.01 mass%.

  Although not shown in the figure, the stirring portion 16 of the composite material 102 is cut, and the stirring portion 16 is formed in the same shape as the tip portion of the electrode tip 12 of the first embodiment. Thus, an electrode tip for resistance spot welding having the same shape as that of Example 1 except that the recess 11 was not formed was produced. The electrode tip was attached to a spot welding apparatus, and spot welding was repeatedly performed on a galvanized steel sheet having a thickness of 1 mm, and the number of times of welding until the electrode tip became unusable was measured. As a result, the electrode tip obtained by the method of this example became unusable after about 4000 spot weldings.

  As shown in the present example, in the manufacturing method according to the present invention, the dispersoid 3 can be dispersed only in the desired part of the composite material 102 by stirring a part of the matrix mass 20. Therefore, it is possible to reduce the use amount of the material to be dispersed 30 and to further reduce the material cost. In addition, the method of the present embodiment can exhibit the same effects as those of the first embodiment.

(Example 3)
In this example, the composite material 103 is formed by the above-described manufacturing method, and then the composite material 103 is subjected to extrusion processing.

  The matrix block 22 in this example is a billet of a Cu-based alloy containing 0.30% by mass of Al and the balance being Cu and unavoidable impurities. In this example, after a matrix mass 22 made of a Cu-based alloy and exhibiting a columnar shape with a diameter of 90 mm and a length of 100 mm is produced, the matrix mass 22 is held at a temperature of 800 ° C. in the air for 2 hours to perform preheating. went. By this preheating, a film of Cu oxide 31 as the material to be dispersed 30 was formed on the surface of the matrix block 22. The thickness of the film of Cu oxide 31 was about 100 μm, and the mass was 3.5 to 9.5 times the mass of Al in the matrix mass 20.

  Moreover, in this example, as shown in FIG. 9, the container 45 provided with the die attachment port 452 for attaching the die 451 was used. The matrix block 22 was placed in the container 45 with the die attachment port 452 closed by the closing member 453.

  After inserting the matrix block 22 having a film of Cu oxide 31 on the surface into the container 45, the probe 47 was inserted into the matrix block 22 in the same manner as in Example 1. Then, the entire matrix block 22 was stirred by the rotation of the probe 47 (arrow 471), and the particles 310 of the Cu oxide 31 as the material to be dispersed 30 were dispersed throughout the matrix block 22. In this example, a shoulder 46 exhibiting a cylindrical shape with a diameter of 90 mm and a probe 47 with a diameter of 40 mm provided with a spiral groove on the outer surface were used.

  After the matrix mass 22 is sufficiently stirred, the closing member 453 of the container 45 is removed, and a die 451 is attached to the die attachment port 452 as shown in FIG. The die 451 in the present example has an opening 454 exhibiting a circular shape with a diameter of 19 mm. After the die 451 was attached to the container 45, the matrix block 22 was pushed out of the die 451 by advancing both the shoulder 46 and the probe 47. Thus, a composite material 103 having a cylindrical shape with a diameter of 19 mm and having a structure in which particles 310 of the Cu oxide 31 as the dispersoid 3 were dispersed in the entire Cu-based alloy as the metal matrix 2 was obtained.

  The composite material 103 thus obtained was held at a temperature of 850 ° C. in a nitrogen atmosphere for 1 hour to internally oxidize Al in the metal matrix to obtain alumina dispersion-strengthened copper. Thereafter, the alumina dispersion strengthened copper was subjected to a drawing process to form a round rod having a diameter of 19 mm. The content of alumina in the obtained alumina dispersion strengthened copper was 0.60% by mass, and the content of metal Al in the metal matrix 2 was 0.01% by mass.

  The obtained round bar of alumina dispersion-strengthened copper is cut into an appropriate length and then subjected to forging to obtain a resistance spot having the same shape as that of the electrode tip 12 of Example 1 except that the recess 11 is not provided. An electrode tip for welding was produced. The electrode tip was attached to a spot welding apparatus, and spot welding was repeatedly performed on a galvanized steel sheet having a thickness of 1 mm, and the number of times of welding until the electrode tip became unusable was measured. As a result, the electrode tip obtained by the method of this example became unusable after about 4000 spot weldings.

  After stirring the matrix mass 22 as in this example, the matrix mass 22 may be extruded. In this case, the same function and effect as those of the first embodiment can be obtained except that the near net shape molding is not performed.

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

  The obtained electrode tip was attached to a spot welding apparatus, spot welding was repeatedly performed on a galvanized steel sheet with a thickness of 1 mm, and the number of weldings until the electrode tip became unusable was measured. As a result, the electrode tip obtained by the method of this example became unusable after about 2000 spot weldings.

  From the comparison between Examples 1 to 3 and Comparative Example 1, an electrode manufactured by the conventional powder metallurgy method by using the composite material manufactured by the manufacturing method of Examples 1 to 3 as an electrode tip for spot welding. It can be understood that the durability in spot welding can be improved as compared to the tip. Furthermore, according to the manufacturing methods of Examples 1 to 3, it can be easily understood that the composite material can be manufactured inexpensively.

  The alumina dispersion strengthened copper obtained by the manufacturing method of Examples 1 to 3 has a smaller content of metal Al than Comparative Example 1, that is, the alumina dispersion strengthened copper by the conventional powder metallurgy method. From these results, it can be easily understood that according to the manufacturing method of Example 2, it is possible to produce alumina dispersion-strengthened copper having higher conductivity than alumina dispersion-strengthened copper by the conventional powder metallurgy method.

  Aspects of the composite material according to the present invention and the method for producing the same are not limited to the aspects of the above-described embodiment, and the configuration can be appropriately changed without impairing the purpose of the present invention.

  The combination of the metal matrix and the dispersoid is not limited to the combination described in Examples 1 to 3, but can be appropriately changed according to the desired characteristics. For example, in Examples 1 to 3, the examples of the composite materials 1, 102 and 103 in which the metal matrix 2 is a Cu-based alloy and the dispersoid 3 is particles 310 of Cu oxide 31 are illustrated. 2 may be pure copper and the dispersoid may be changed to alumina. In this case, the alumina dispersion strengthened copper can be produced without internal oxidation treatment by stirring the matrix block made of pure copper and the material to be dispersed which is made of alumina or r. Also, the metal matrix may be pure aluminum or an aluminum alloy, and the dispersoid may be changed to Fe, Si, ceramics or the like.

  In Examples 1 to 3, an example was shown in which a film of Cu oxide 31 as the material to be dispersed 30 was formed on the surface of matrix masses 20 and 22 in advance. Material to be dispersed can also be supplied. In this case, for example, a supply port for supplying the material to be dispersed is provided on the wall surface of the container, the tip of the double acting tool, etc. be able to.

  Although Examples 1-3 show an example which performs remaining heat before stirring matrix masses 20 and 22, it is also possible to stir matrix masses without preheating. Even in the case where preheating is not performed, since the frictional heat is generated by the rotation of the probe, the matrix block can be plastically flowed as in the case of performing the preheating.

DESCRIPTION OF SYMBOLS 1, 102, 103 Composite material 2 Metal matrix 20, 22 Matrix block 3 Dispersion quality 30 Dispersion scheduled material 41, 45 Container 42 Double acting tool 43, 46 Shoulder 44, 47 probe

Claims (9)

A method of manufacturing a composite material having a metal matrix and a dispersoid dispersed in the metal matrix,
Place a matrix block to be the metal matrix in a container,
Inserting into the container a double acting tool comprising a shoulder having a columnar shape and a probe penetrating the central axis of the shoulder, wherein the shoulder and the probe can be driven separately;
Bringing the shoulder into contact with the matrix mass and inserting the probe into the matrix mass;
The dispersion is performed by causing the matrix mass to plastically flow while rotating the probe in a state in which the matrix mass and the material to be dispersed which is the dispersoid are in contact while constraining the deformation of the matrix mass by the shoulder. Dispersing scheduled material into the matrix mass,
Method of manufacturing composites.   After dispersing the material to be dispersed in the matrix block, the probe is removed from the matrix block to form a recess in the matrix block, and then the shoulder is filled into the matrix block to backfill the recess. A method of manufacturing the composite material according to claim 1.   The method according to claim 1 or 2, wherein the material to be dispersed is dispersed in the entire matrix mass by plastically flowing the entire matrix mass by rotation of the probe.   The stirring includes the metal matrix and the dispersoid dispersed in the metal matrix by plastically flowing only the periphery of the probe in the matrix mass by rotation of the probe, and the metal matrix includes the stirring. The manufacturing method of the composite material of Claim 1 or 2 which forms the non-stirring part which follows a part.   The matrix mass is made of a Cu-based alloy containing 0.05 to 1.2% by mass of Al, and the material to be dispersed is made of a Cu oxide. The manufacturing method of the composite material as described in.   The method of manufacturing a composite according to claim 5, 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 manufacturing method of the composite material of Claim 5 or 6 which further heats the said composite material to 700-1050 degreeC after producing the said composite material, and carries out internal oxidation of Al in the said metal matrix. Al: a metal matrix made of a Cu-based alloy containing 0.30 mass% or less,
And a dispersoid composed of 0.050% to 2.0% by mass of alumina dispersed in the metal matrix.
Composite material.   The composite material according to claim 8, comprising: a stirring portion provided with the metal matrix and the dispersoid; and a non-stirring portion formed of the metal matrix and continuous with the stirring portion.

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