JP2017047448A - Manufacturing method of copper-clad aluminum composite extrusion material, copper-clad aluminum conductive wire material and manufacturing method of the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a manufacturing method of copper-clad aluminum composite extrusion material made by integrating Al material in which the thickness of a Cu pipe corresponding part is made thickened and a Cu pipe, and so forth.SOLUTION: A manufacturing method of copper-clad aluminum composite extrusion material 20 includes: a first process S1 of respectively selecting a cylindrical Cu pipe 22 made of Cu type material and a columnar Al material 21 made of Al type material such that a ratio of deformation resistance value at 500°C becomes less than 10; a second process S2 of charging the Al material 21 into the Cu pipe 22; a third process S3 of closing both end openings of the Cu pipe 22 while vacuuming the interior of the Cu pipe 22 into which the Al material 21 is charged to form a composite billet 23 of the Cu pipe 22 in which the Al material 21 is sealed under vacuum; and a fourth process S4 of providing a rod-like copper-clad aluminum composite extrusion material 20 made by integrating the Al material 21 and the Cu pipe 22 by performing hot extrusion while heating the composite billet 23 into 400 to 450°C.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a method for producing a copper-coated aluminum composite extruded material, a copper-coated aluminum conductor wire, and a method for producing the same.

  The copper-coated aluminum conductor wire is formed by integrally forming a copper (Cu) coating layer around an aluminum (Al) core, and can be reduced in weight compared to a Cu wire. Are used as conductor lines used for micro coils such as voice coils.

  Copper-coated aluminum conductor wires are generally manufactured by forming a Cu coating layer around the Al core and then performing a wire drawing process to reduce the wire diameter to a predetermined size. is there. At this time, as a conventional method for forming the Cu coating layer around the Al core portion, for example, a so-called forming method (for example, patent) in which a copper tape (copper foil) is wound around an aluminum wire to form a Cu coating layer. Reference 1) or a so-called plating method (for example, Patent Document 2) in which a Cu coating layer is formed by precipitating Cu or a Cu alloy on the outer peripheral surface of an Al wire.

  However, the forming method tends to become difficult to form as the copper tape wound around the Al core becomes thicker. Also, the plating method is limited to the thickness of the Cu plating layer that can be formed uniformly. Therefore, in both methods, the thickness of the Cu coating layer that can be formed is considered to be about 25% at the maximum in terms of the (cut) area ratio of the Cu coating layer in the copper-coated aluminum conductor wire. .

  Also, recently, depending on the industrial products to which the wire is applied, the electrical conductivity of the conventional copper-coated aluminum conductor wire is not sufficient, and the need to develop a copper-coated aluminum conductor wire having higher conductivity is increasing. Furthermore, in accordance with the customer's request, the thickness of the copper coating layer constituting the copper-coated aluminum conductor wire is the area ratio of the Cu coating layer in the copper-coated aluminum conductor wire, and the range of a thin wall of 25% or less Therefore, it is desirable to have a method for producing a copper-coated aluminum conductor wire that can be easily set in a wide range up to a thickness range exceeding 25%.

  In order to increase the electrical conductivity as compared with the conventional copper-coated aluminum conductor wire, the thickness of the Cu coating layer formed around the Al core is made thicker than the conventional copper-coated aluminum conductor wire (for example, copper-coated aluminum conductor). The area ratio of the Cu coating layer occupying the conductor wire is 30% or more), but it is difficult to form such a thick Cu coating layer by a conventional method such as a forming method or a plating method. In addition, since the Cu tape (Cu coating layer) formed by the forming method is inferior in adhesion to the Al core part, a part of the Cu tape is peeled off after the subsequent wire drawing process, and the surface of the Al core part is removed. A portion of the Cu plating tends to be exposed, and the Cu plating (Cu coating layer) formed by the plating method can only be thinly formed. There is a tendency for a part of the surface to be exposed, and in any case, if a wire having such a surface state is used continuously, corrosion of different metals will start from the surface exposed part of the Al core, which is the worst. In this case, the Al core part may be broken.

Japanese Patent No. 5203817 JP 2004-39477 A

  The object of the present invention is to make the area ratio of the Cu coating layer to the Al core part higher (for example, the copper area ratio is 30%) than the conventional copper-coated aluminum conductor wire (for example, the copper area ratio is 25% or less). The copper-coated aluminum conductor wire having a higher electrical conductivity than the conventional copper-coated aluminum conductor wire while maintaining a lighter weight than the conventional copper wire material (100% in terms of the copper area ratio). Is to provide.

  Another object of the present invention is to appropriately select a columnar Al material and a cylindrical Cu pipe, form a predetermined composite billet with the selected Al material and the Cu pipe, and use this composite billet at a predetermined temperature. It is an object of the present invention to provide a method for producing a copper-clad aluminum composite extruded material having a cross-sectional area ratio that is the same as or close to the cross-sectional area ratio of an Al material and a Cu pipe, constituting a composite billet. The copper-coated aluminum composite extruded material is suitable for use as a wire drawing material for producing a copper-coated aluminum conductor wire, as well as a columnar or bar-shaped conductive member (for example, a bus bar) made of a copper material. If it is used as a substitute material for these various members, the weight can be reduced.

  Furthermore, the other object of this invention is to provide the manufacturing method of the copper covering aluminum conductor wire which enables manufacture of the covering aluminum conductor wire with the high area ratio of Cu coating layer with respect to Al core part mentioned above.

The gist configuration of the present invention is as follows.
(1) a first step of selecting a cylindrical Cu pipe made of a Cu-based material and a columnar Al material made of an Al-based material so that the ratio of deformation resistance values at 500 ° C. is less than 10, respectively; A second step of charging the Cu pipe with the Al material using the selected Cu pipe and the Al material, and the Cu pipe in a state in which the inside of the Cu pipe in which the Al material is charged is evacuated. A third step of forming a Cu bill composite billet in which the Al material is vacuum-sealed, and hot extrusion while heating the composite billet to 400 to 450 ° C. And a fourth step of obtaining a rod-like copper-coated aluminum composite extruded material obtained by integrating the material and the Cu pipe. A method for producing a copper-coated aluminum composite extruded material, comprising:

(2) The manufacturing method of the copper covering aluminum composite extrusion material as described in said (1) whose ratio of the said deformation resistance value in the said 1st process is 3 or less.

(3) The copper-coated aluminum composite according to (1) or (2), further including a step of forming a diffusion barrier layer made of Nb or Ta on the surface of the Al material prior to performing the second step. Method for producing extruded material.

(4) The copper-coated aluminum composite according to any one of the above (1) to (3), wherein a reduction in area during hot extrusion in the fourth step is 85.0% or more and less than 99.9%. Method for producing extruded material.

(5) The ratio of the cross-sectional area of the Cu pipe to the cross-sectional area of the Al material selected in the first step constitutes the copper-coated aluminum composite extruded material obtained in the fourth step. The ratio of the cross-sectional area of the portion corresponding to the Cu pipe to the cross-sectional area of the portion corresponding to the material is in the range of 0.43 to 2.30, according to any one of (1) to (4) above. A method for producing a copper-coated aluminum composite extruded material.

(6) The copper-coated aluminum composite extruded material produced by using the method for producing a copper-coated aluminum composite extruded material according to any one of (1) to (5) above is subjected to wire drawing to provide a copper coating. The manufacturing method of a copper covering aluminum conductor wire including the 5th process of obtaining an aluminum conductor wire.

(7) The ratio of the cross-sectional area of the portion corresponding to the Cu pipe to the cross-sectional area of the portion corresponding to the Al material that constitutes the copper-coated aluminum composite extruded material obtained in the fourth step is the fifth The copper according to (6) above, which is in the range of 0.43 to 2.30 of the ratio of the cross-sectional area of the Cu coating layer to the cross-sectional area of the Al core portion, which constitutes the copper-coated aluminum conductor wire obtained in the process. A method for producing a coated aluminum composite extruded material.

(8) A copper-coated aluminum conductor wire having an Al core portion made of an Al-based material and a Cu coating layer made of a Cu-based material disposed around the Al core portion. A copper-coated aluminum conductor wire, wherein the area ratio of the Cu coating layer to the Al core portion is 0.43 or more, as seen in the cross section of FIG.

(9) The copper-coated aluminum conductor wire according to (8), wherein the area ratio of the Cu coating layer to the Al core is 0.82 to 1.23.

  According to the present invention, there is provided a copper-coated aluminum conductor wire having an Al core portion made of an Al-based material and a Cu coating layer made of a Cu-based material disposed around the Al core portion. The area ratio of the Cu coating layer with respect to the area ratio of the copper coating layer is 0.43 or more, and the area ratio of the Cu coating layer to the Al core portion is defined as a conventional copper-coated aluminum conductor wire And lower than 25%) (for example, 30% or more in terms of the copper area ratio), while maintaining a lighter weight than conventional copper wire (100% in terms of the copper area ratio). Thus, it has become possible to provide a copper-coated aluminum conductor wire having a high conductivity that has not been obtained with conventional copper-coated aluminum conductor wires.

  Further, according to the present invention, a cylindrical Cu pipe made of a Cu-based material and a columnar Al material made of an Al-based material are selected so that the ratio of deformation resistance values at 500 ° C. is less than 10. A first step, a second step of using each selected Cu pipe and Al material, and charging the Cu pipe with an Al material, and the Cu pipe filled with the Al material in a vacuum-evacuated state. A third step of forming a composite billet of a Cu pipe in which the opening of both ends is sealed and the Al material is vacuum-enclosed, and the composite billet is hot-extruded while being heated to 400 to 450 ° C. And a fourth step of obtaining a rod-shaped copper-coated aluminum composite extruded material formed by integrating the parts, particularly in a portion corresponding to a Cu pipe that could not be manufactured by a conventional manufacturing method. Has become possible to thicken provide manufacturing methods of (e.g., the in to 30% or more copper area ratio) was bar-shaped copper-coated aluminum composite extrusions of. The copper-coated aluminum composite extruded material is suitable for use as a wire drawing material for producing a copper-coated aluminum conductor wire, as well as various kinds of rod-shaped conductive members (for example, bus bars) made of a copper material. If it is used as a substitute for a member, the weight can be reduced.

  Furthermore, according to the present invention, it is possible to provide a method for producing a copper-clad aluminum conductor wire that makes it possible to produce a coated aluminum conductor wire that has a particularly high area ratio of the Cu coating layer to the Al core described above.

FIG. 1 is a diagram schematically showing a cross section of a copper-coated aluminum conductor wire according to the present invention. FIGS. 2A to 2D are views for explaining a method for producing a copper-coated aluminum composite extruded material according to the present invention, wherein FIG. 2A is a production flow diagram, and FIG. The figure which shows the state at the time of charging (assembling), (c) is the figure which shows the state when forming a composite billet, and (d) is the figure which shows the state when hot extruding the composite billet is there. FIGS. 3A to 3E are views for explaining a method for producing a copper-coated aluminum conductor wire according to the present invention, in which FIG. 3A is a production flow diagram, and FIG. The figure which shows the state when charging (assembling), (c) is the figure which shows the state when forming a composite billet, (d) is the figure which shows the state when hot extruding a composite billet, and ( It is a figure which shows a state when e) draws a copper covering aluminum composite extruded material.

  Embodiments of the present invention will be described below in detail with reference to the drawings.

(Copper-coated aluminum conductor wire)
FIG. 1 schematically shows a cross section of a copper-coated aluminum conductor wire according to the present invention. In FIG. 1, reference numeral 10 denotes a copper-coated aluminum conductor wire, 11 denotes an aluminum (Al) core, and 12 denotes It is a copper (Cu) coating layer.

  The illustrated copper-coated aluminum conductor wire 10 is mainly composed of an Al core portion 11 and a Cu coating layer 12 disposed around the Al core portion 11.

  The Al core 11 is made of an Al-based material made of Al or an Al alloy, and is particularly made of a 5000-based (Al-Mg-based) or 6000-based (Al-Mg-Si-based) Al alloy having high mechanical strength. It is preferable that it is excellent in the uniformity of the cross-sectional area ratio when extruded together with the Cu coating layer 12.

  Further, the Cu coating layer 12 is made of a Cu-based material made of Cu or a Cu alloy, and particularly made of a Ni—Cu—Ni alloy or a Cu—Zn alloy is extruded together with the Al core portion 11. It is preferable in that it has excellent uniformity in cross-sectional area ratio.

  And the copper coating aluminum conductor wire 10 of this invention was not able to manufacture the thickness t of Cu coating layer 12 with respect to Al core part 11 with the conventional manufacturing method, for example, Cu coating layer which occupies for copper coating aluminum conductor wire 10 12 (cut) area ratio is 30% or more. More specifically, the Cu covering layer 12 has an area S1 of the Al core portion 11 as seen in a cross section of the copper-covered aluminum conductor wire 10. It is an essential invention specific matter that the ratio S2 / S1 of the area S2 is 0.43 or more. And the copper covering aluminum conductor wire 10 of this invention employ | adopts this structure, It is lightweight compared with the conventional copper wire, However, The high electroconductivity which was not obtained with the conventional copper covering aluminum conductor wire until now Can have a rate.

  In addition, the copper-coated aluminum conductor wire 10 of the present invention contributes to weight reduction at the Al core portion 11, and at the portion of the Cu coating layer 12 that can be formed thicker than the conventional copper-coated aluminum conductor wire, the conductivity is increased. It can be configured to contribute to the improvement of When the ratio S2 / S1 of the area S2 of the Cu coating layer 12 to the area S1 of the Al core portion 11 is less than 0.43, the effect of improving the conductivity is not significant as compared with the conventional copper-coated aluminum conductor wire, This is because, depending on the industrial product configured using the wire, it is assumed that the required level of electrical conductivity is not satisfied, and the types and applications of the industrial product that can use the copper-coated aluminum conductor wire are limited.

  Further, in the copper-coated aluminum conductor wire 10, when importance is attached to satisfying both light weight and high conductivity in a balanced manner, the area ratio S2 / S1 of the Cu coating layer 12 to the Al core portion 11 is set to 0.82. It is more preferable to set it to -1.23.

  Furthermore, although the copper covering aluminum conductor wire 10 of FIG. 1 has shown the case where it comprises with the Al core part 11 and the Cu coating layer 12, it is Nb or Ta between Al core part 11 and the Cu coating layer 12. It is also possible to form a diffusion prevention layer (not shown). When the diffusion prevention layer is subjected to heat treatment such as hot extrusion during the production of the copper-coated aluminum conductor wire 10, Al in the Al core 11 and Cu in the Cu coating layer 12 are thermally diffused to each other. Thus, it is possible to effectively prevent the formation of an Al—Cu phase at the interface between the Al core portion 11 and the Cu coating layer 12 or the like.

(Method for producing copper-coated aluminum composite extruded material)
Next, the manufacturing method of the copper covering aluminum composite extrusion material 20 according to this invention is demonstrated.
Fig.2 (a) shows the manufacture flow of the copper covering aluminum composite extrusion material according to this invention. In the method for producing the copper-coated aluminum composite extruded material 20 of the present invention, a cylindrical Al pipe 21 made of an Al-based material and a cylindrical Cu pipe 22 made of a Cu-based material have a deformation resistance value ratio of 10 at 500 ° C. 1st process S1 which selects so that it may become less than each, 2nd process S2 which inserts Al material 21 in Cu pipe 22 using each selected Cu pipe 22 and Al material 21, and Al material 21 is charged In a state where the inside of the Cu pipe 22 is evacuated, both ends of the Cu pipe 22 are sealed to form a composite billet 23 of the Cu pipe 22 in which the Al material 21 is vacuum-sealed, and the composite billet 23 A rod-like copper-coated aluminum composite extruded material 20 in which the Al material 21 and the Cu pipe 22 are integrated by hot extrusion while heating to 400 to 450 ° C. In which sequentially perform a fourth step S4 for obtaining.

  The method for producing the copper-coated aluminum composite extruded material 20 of the present invention is a method for obtaining the copper-coated aluminum composite extruded material 20 by hot-extruding a composite billet 23 composed of an Al material 21 and a Cu pipe 22. Since the composite billet 23 that performs hot extrusion is composed of different materials of the Al material 21 and the Cu pipe 22, when the deformation resistance values of the Al material 21 and the Cu pipe 22 are greatly different, after the hot extrusion, A portion corresponding to an Al material constituting the obtained copper-coated aluminum composite extruded material 20 (hereinafter sometimes referred to as “Al material equivalent portion”) and a portion corresponding to a Cu pipe (hereinafter referred to as “Cu pipe equivalent portion”). However, it is not uniformly extruded, and the area ratio of the Cu pipe equivalent part to the Al material equivalent part cannot be the expected area ratio. A similar problem is also the case of applying the drawing occurs. For this reason, in the first step, the cylindrical Cu pipe 22 made of a Cu-based material and the columnar Al material 21 made of an Al-based material are each set so that the deformation resistance ratio at 500 ° C. is less than 10. select.

  In general, it is known that an Al-based material is softer than a Cu-based material and has a small deformation resistance value. The inventors selected an Al-based material composed of pure Al and a Cu-based material composed of a Cu-10 mass% Ni alloy, and manufactured a copper-coated aluminum composite extruded material according to the manufacturing method of the present invention. The copper-coated aluminum composite extruded material has a phenomenon in which the outer diameter is intermittently large and small, that is, a non-uniform shape called a so-called sausaging phenomenon. It has been found that an aluminum composite extrusion cannot be obtained. The ratio of the deformation resistance value between the Al-based material made of pure Al and the Cu-based material made of Cu-10 mass% Ni alloy used at this time was about 15.

  Therefore, the present inventors prepared Cu pipes made of various Cu-based materials having different compositions and various Al materials having different compositions. With various combinations of Cu pipes and Al materials, the deformation resistance value can be reduced. Composite billets with different differences were produced, and the shape of the extruded material obtained by hot extrusion of each composite billet was examined. As a result, any extruded material obtained by hot extrusion of a composite billet prepared such that the ratio of the deformation resistance value at 500 ° C. between the Cu pipe and the Al material is less than 10 has a uniform shape (bar shape). I found.

For this reason, in the present invention, the cylindrical Cu pipe 22 made of a Cu-based material and the columnar Al material 21 made of an Al-based material are each selected so that the ratio of deformation resistance values at 500 ° C. is less than 10. This is an essential invention specific matter. In addition, before and after hot extrusion and wire drawing, the cross section in which the area ratio of the Cu pipe (Cu coating layer) to the Al material (Al core portion) is equal is substantially similar, When it is necessary to further suppress the change in the cross-sectional area ratio, it is preferable that the ratio of the deformation resistance values is 3 or less.
The ratio of the cross-sectional area of the Cu pipe 22 to the cross-sectional area of the Al material 21 selected in the first step S1 constitutes the copper-coated aluminum composite extruded material 20 obtained in the fourth step S4. The ratio of the cross-sectional area of the Cu pipe equivalent part to the cross-sectional area of 0.43 to 2.30 is intended to be the thickness of the Cu pipe equivalent part constituting the copper-coated aluminum composite extruded material 20 It is preferable in that the thickness can be easily set.

  2nd process S2 is a process (FIG.2 (b)) which inserts the Al material 21 in Cu pipe 22 using Cu pipe 22 and Al material 21 which were each selected in 1st process S1. Since the Cu pipe 22 facilitates the charging of the Al material 21 and evacuates the Cu pipe 22 in the third step S3 performed thereafter, the inner diameter of the Cu pipe 22 is set to the diameter of the Al material 21. It is preferable to make it larger by about 0.1 to 0.5 mm. In addition, in the copper-coated aluminum composite extruded material 20, when a diffusion prevention layer such as Nb is provided between the Al material equivalent part and the Cu pipe equivalent part, a foil such as Nb is wound around the surface of the Al material 21. The Al material 21 may be inserted into the Cu pipe 22. In addition, since the Al material 21 is vacuum-sealed in the Cu pipe 22 in the subsequent third step S3, the length of the Al material 21 is the same as the length of the Cu pipe 22 or about 3 to 10 mm shorter. It is preferable to do. Further, since the inner surface of the Cu pipe 22 and the surface of the Al material 21 need to be closely integrated after hot extrusion, the Cu pipe 22 and the Al material 21 are charged with the Al material 21 in the Cu pipe 22. It is preferred to clean the surface before. The surface of the Cu pipe 22 may be formed by acid cleaning. However, since the Al material 21 is a metal that is soluble in both acid and alkali, the surface is not cleaned with acid or alkali, and the oxide film is removed by machining. It is preferable to clean the surface only by degreasing.

  As another embodiment, a step of forming a diffusion barrier layer made of Nb or Ta on the surface of the Al material 21 may be further performed prior to performing the second step S2. Since this diffusion barrier layer is particularly effective for preventing thermal diffusion of Al and Cu, the copper-coated aluminum composite extruded material 20 (and the copper-coated aluminum conductor wire 10 produced using this extruded material 20) Is particularly preferable when a high-temperature heat history is required during hot extrusion or other manufacturing processes.

  The third step S3 is a second step S2, in which the opening of both ends of the Cu pipe 22 is sealed in a state where the inside of the Cu pipe 22 in which the Al material 21 is charged is evacuated, and the Al material 21 is vacuum-encapsulated. This is a step of forming the composite billet 23 of the pipe 22 (FIG. 2C). In the manufacturing method of the present invention, the composite billet 23 is heated to a high temperature of 400 ° C. or higher during hot extrusion. Therefore, when the composite billet 23 is formed of the Al material 21 and the Cu pipe 22, the Al material 21 When air is present between the Cu pipe 22 and the Cu pipe 22, the inner surface of the Cu pipe 22 is easily oxidized under high temperature heating, and when hot extrusion is performed with an oxide film formed on the inner surface of the Cu pipe 22, the adhesion of Cu to Al Therefore, in the present invention, the composite billet 23 to be hot extruded is sealed at both ends of the Cu pipe 22 in a state where the inside of the Cu pipe 22 into which the Al material 21 is charged is evacuated. It is necessary to form the composite billet 23 of the Cu pipe 22 in which the material 21 is vacuum-sealed.

  Various methods can be considered as a method of forming the composite billet 23. For example, first, the Cu pipe 22 charged with the Al material 21 is set in a vacuum chamber so as to be rotatable, and then the Cu pipe. The lids 24 and 24 made of Cu are put on both ends of 22. At this time, although both end openings of the Cu pipe 22 are closed by the lid 24, they are not in an airtight (sealed) state in which gas cannot enter and exit, so the inside and outside of the Cu pipe 22 (inside the vacuum chamber) Is in communication and allows gas to enter and exit freely. Thereafter, the inside of the vacuum chamber is evacuated, and the air existing inside the Cu pipe 22 with the lid 24 is sucked out and discharged, and then an electron gun (cathode) of an electron beam welding machine installed in the vacuum chamber. ) The electron beam emitted from 25 is welded by irradiating the entire circumference of the fitting portion between the Cu pipe 22 and the lid 24 while rotating the Cu pipe 22, and the inside of the Cu pipe 22 in which the Al material 21 is inserted. The openings at both ends of the Cu pipe 22 can be sealed in a vacuumed state, whereby the composite billet 23 of the Cu pipe 22 in which the Al material 21 is vacuum-sealed can be formed. Even if the composite billet 23 thus formed is subsequently hot extruded in the atmosphere, the inner surface of the Cu pipe 22 does not oxidize, and the copper-clad aluminum composite extruded material is always stably and uniformly shaped. A composite billet 23 suitable for obtaining 20 can be formed.

  In the fourth step S4, the composite billet 23 is hot-extruded while being heated to 400 to 450 ° C., thereby obtaining a rod-like copper-coated aluminum composite extruded material 20 in which the Al material and the Cu pipe are integrated ( FIG. 2 (d)). The heating temperature of the composite billet 23 at the time of hot extrusion is set to 400 to 450 ° C. When the heating temperature is lower than 400 ° C., the pressure of the press machine 26 used for hot extrusion becomes too high, and the area reduction rate during hot extrusion cannot be increased. This is because the wire drawing process must be performed or the number of wire drawing processes must be increased, resulting in an inefficient production. Further, if the heating temperature is higher than 450 ° C., melting of Al and thermal diffusion of Al and Cu are likely to occur. In the present invention, the composite billet 23 is hot-extruded while being heated to 400 to 450 ° C., whereby the Al material 21 and the Cu pipe 22 are closely integrated to form a uniform bar-shaped copper-coated aluminum composite extruded material. 20 can be obtained. Specifically, the hot extrusion of the composite billet 23 is performed by placing the composite billet 23 in a container 27, heating the composite billet 23 to 400 to 450 ° C., and applying pressure to the composite billet by a press machine 26 and extruding it from a die. Good. The number of hot extrusions is not particularly limited, but is preferably set once in consideration of yield and cost.

  Further, the copper-coated aluminum composite extruded material 20 obtained by the method for producing a copper-coated aluminum composite extruded material of the present invention is used, and the extruded material 20 is subjected to wire drawing to obtain a copper-coated aluminum conductor wire 10 having a predetermined wire diameter. In the case of forming, it is preferable to increase the area reduction ratio at the time of hot extrusion to 85.0% or more and less than 99.5% because the number of wire drawing processes can be reduced. If the area reduction ratio during hot extrusion is less than 85.0%, the diameter of the extruded material 20 after hot extrusion cannot be sufficiently reduced, and the number of wire drawing operations increases, producing It is not preferable because the problem of an increase in the size of the equipment occurs, and the reduction in area is less than 99.5% in consideration of the press pressure limit of the hot extrusion press 26. It is.

  Moreover, the formation speed of the extruded material 20 at the time of hot extrusion is not particularly limited, but may be 5 to 100 mm / sec, for example. Furthermore, the angle of the die 28 used for hot extrusion is preferably 60 to 120 °. This is because if the angle of the die 28 is 60 ° or more, Cu and Al in the extruded material 20 obtained by hot extrusion tend to be integrated with good adhesion, and the angle of the die 28 is 120 ° or less. This is because the proportion of defective portions generated at both ends of the extruded material 20 obtained by hot extrusion is small, and the extruded material 20 tends to be manufactured with a high yield. Note that the "die angle" here refers to the inclined surface of the die that extends in a frustoconical shape toward the extrusion direction of the composite billet when viewed in the axial cross section of the die, and the vertex of the virtual cone. It means the angle of intersection (vertical angle) when the inclined surfaces are crossed with each other.

(Method for producing copper-coated aluminum conductor wire)
Moreover, the manufacturing method of the copper covering aluminum conductor wire 10 according to this invention is the 5th process (drawing process) to the copper covering aluminum composite extruded material manufactured using the manufacturing method of the copper covering aluminum composite extruded material mentioned above ( It is a manufacturing method including FIG.3 (e)). Fig.3 (a) shows the manufacture flow of the copper covering aluminum conductor wire 10 according to this invention. In addition, from 1st process S1 to 5th process S5 which are the main processes of the manufacturing method of the copper covering aluminum conductor wire 10 of this invention, from 1st process S1 to 4th process S4, the copper coating of this invention mentioned above is mentioned. It is the same as the manufacturing method of an aluminum composite extrusion material, FIG.3 (a)-FIG.3 (d) and FIG.2 (a)-(d) have shown the same process, and abbreviate | omit description.

  The wire drawing process is performed a plurality of times. The area reduction rate in one wire drawing is preferably 15 to 30%. If the area reduction ratio exceeds 30%, there is a risk of disconnection. If the area reduction ratio is less than 15%, the number of wire drawing operations increases and the working force is sufficiently transmitted to the inside of the wire. This is not preferable because non-uniform processing is likely to occur.

  Further, the wire drawing is performed at room temperature, and when it is necessary to remove the processing strain introduced into the copper coating layer 12 by the processing, it is performed once or a plurality of times at a temperature of about 200 to 300 ° C. during the processing. It is preferable to perform the intermediate annealing.

  Further, the ratio of the cross-sectional area of the Cu pipe equivalent part to the cross-sectional area 0.4 of the Al material equivalent part constituting the copper-coated aluminum composite extruded material 20 obtained in the fourth process S4 is obtained in the fifth process S5. It is the copper coating that the ratio S2 / S1 of the cross-sectional area S2 of the Cu coating layer 12 to the cross-sectional area S1 of the Al core 11 constituting the copper-coated aluminum conductor wire 10 is in the range of 0.43 to 2.30. This is preferable in that the thickness of the Cu coating layer 12 constituting the aluminum conductor wire 10 can be easily set to a desired thickness.

  The method for producing the copper-coated aluminum conductor wire 10 of the present invention can produce an extremely fine copper-coated aluminum conductor wire having a wire diameter of about 50 to 100 μm, and has a conductivity close to that of a copper wire, while having a conductivity close to that of a copper wire. Is also suitable for use as a conductor wire used for a micro coil such as a voice coil as well as a center line of an automobile electric wire or a coaxial cable. Yes.

  In addition, the manufacturing method of the copper-coated aluminum conductor wire of the present invention increases the thickness of the Cu coating layer (for example, an Al core portion) that could not be manufactured by a conventional manufacturing method such as a forming method or a plating method. In addition to making it possible to produce a copper-coated aluminum conductor wire with an area ratio of the Cu coating layer to 0.43 or more), a conventional copper-coated aluminum conductor wire with a thin Cu coating layer is produced. Therefore, it is possible to supply a copper-coated aluminum conductor wire in which the thickness of the Cu coating layer is set to a desired thickness over a wide range according to the customer's request.

  Next, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples.

(Example I: Production of copper-coated aluminum composite extruded material)
Cylindrical Cu pipes 22 (outer diameter: 200 mm, inner diameter: 130.0 mm, length: 805.0 mm) made of various Cu-based materials shown in Table 1, and circles made of various Al-based materials shown in Table 1 A columnar Al material 21 (diameter: 129.5 mm, length: 800.0 mm) was selected. Table 1 shows the ratio of the deformation resistance values of the Cu pipe 22 and the Al material 21.

Next, the inner surface and outer surface of the Cu pipe 22 are acid cleaned, and the surface of the Al material 21 is subjected to surface cleaning only by degreasing after the oxide film is removed by machining, and then the Cu pipe 22 is subjected to Al cleaning. Material 21 was charged. Thereafter, a Cu lid 24 is put on both ends of the Cu pipe 22 charged with the Al material 21, the Cu pipe 22 is set to be rotatable in the vacuum chamber, and the inside of the vacuum chamber is vacuumed to 10 ⁻⁵ Pa or less. Then, the air existing inside the Cu pipe 22 with the lid 24 is sucked and discharged outside, and then the electron beam emitted from the electron gun 25 of the electron beam welder installed in the vacuum chamber is While rotating the Cu pipe 22, the entire circumference of the fitting portion between the Cu pipe 22 and the lid 24 is irradiated and welded, and both ends of the Cu pipe 22 are evacuated while the inside of the Cu pipe 22 in which the Al material 21 is charged is evacuated. By sealing the opening, the composite billet 23 of the Cu pipe 22 in which the Al material 21 was vacuum-sealed was formed. Next, the composite billet 23 is hot-extruded while being heated to 430 ° C., and the Al material 21 and the Cu pipe 22 are integrated. A rod-shaped copper-coated aluminum composite having an outer diameter of 75 mm and a length of 10 m. Extruded material 20 (Examples 1-1 to 1-4) was produced. The area reduction rate during hot extrusion was 85.0%. Further, in the produced copper-coated aluminum composite extruded material 20, a length portion corresponding to 90% of the total length excluding a length portion corresponding to 5% of the total length from both ends thereof is referred to as a so-called phenomenon. Table 1 shows the results of visual observation of the appearance of uniform shapes. In Table 1, “x” indicates that the length corresponding to 90% of the total length of the copper-coated aluminum composite extruded material has a fluctuation range of the outer diameter of the extruded material with respect to the extruded diameter (75 mm) during hot extrusion is ± It shows the case where the non-uniform shape is generated or exceeds 2%, or the fracture occurs (fail), and “◎” and “◯” indicate the extrusion diameter (75 mm) at the time of hot extrusion. This indicates the case where the fluctuation range of the outer diameter of the extruded material is within ± 2% (accepted product), and in particular, “」 ”indicates the case where the fluctuation range is within ± 1%.
For reference, a copper-coated aluminum composite extruded material (comparative) was produced by the same manufacturing method as in the examples except that a combination of a Cu pipe and an Al material having a deformation resistance ratio outside the proper range of the present invention was used. Examples 2-1 and 2-2) were prepared and are also shown in Table 1.

  From the results shown in Table 1, in Examples 1-1 to 1-4, a uniform bar-shaped copper-coated aluminum composite extruded material was obtained. Moreover, when the extrusion material obtained in Examples 1-1 to 1-4 was then cut, and the area ratio of the Cu pipe equivalent part to the Al material equivalent part was examined along the longitudinal direction of the extrusion material, Was almost 1. On the other hand, in Comparative Examples 1-1 and 1-2, in which the deformation resistance ratio is outside the proper range of the present invention, both had non-uniform shapes. Moreover, when the extrusion material obtained by Comparative Examples 1-1 and 1-2 was cut | disconnected after that and the area ratio of the Cu pipe equivalent part with respect to Al material equivalent part was investigated along the longitudinal direction of an extrusion material, it was Was also in the range of 0.5 to 1.5, and it was confirmed that there was a large variation in the thickness of the portion corresponding to the Cu pipe.

(Example II: Production of copper-coated aluminum conductor wire)
The cylindrical Cu pipe 22 made of pure Cu and the columnar Al material 21 made of No. 6063 Al alloy have various cross-sectional areas having different area ratios of the Cu pipe to the Al material shown in Table 2. I prepared something. The prepared Cu pipe and the Al material have a deformation resistance ratio of 2.0, and the area ratio of the Cu pipe to the Al material constituting the composite billet composed of the Cu pipe and the Al material is finally obtained. The area ratio of the Cu coating layer to the Al core portion constituting the copper-coated aluminum conductor wire to be obtained was almost the same.

Next, the inner surface and outer surface of the Cu pipe 22 are acid cleaned, and the surface of the Al material 21 is subjected to surface cleaning only by degreasing after the oxide film is removed by machining, and then the Cu pipe 22 is subjected to Al cleaning. Material 21 was charged. Thereafter, a Cu lid 24 is put on both ends of the Cu pipe 22 charged with the Al material 21, the Cu pipe 22 is set to be rotatable in the vacuum chamber, and the inside of the vacuum chamber is vacuumed to 10 ⁻⁵ Pa or less. Then, the air existing inside the Cu pipe 22 with the lid 24 is sucked and discharged outside, and then the electron beam emitted from the electron gun 25 of the electron beam welder installed in the vacuum chamber is While rotating the Cu pipe 22, the entire circumference of the fitting portion between the Cu pipe 22 and the lid 24 is irradiated and welded, and both ends of the Cu pipe 22 are evacuated while the inside of the Cu pipe 22 in which the Al material 21 is charged is evacuated. By sealing the opening, the composite billet 23 of the Cu pipe 22 in which the Al material 21 was vacuum-sealed was formed. Next, the composite billet 23 is hot-extruded while being heated to 430 ° C., so that the rod-like copper-coated aluminum composite extruded material 20 (outer diameter: 75 mm, length) formed by integrating the Al material 21 and the Cu pipe 22. : 6 m). The area reduction rate during hot extrusion was 85.0%. Thereafter, the extruded material 20 was subjected to an intermediate annealing at 250 ° C., and then subjected to a wire drawing process having a surface reduction rate of 25% 30 times to obtain a copper-coated aluminum conductor wire having a wire diameter of 8 mm (Example 2-1 Table 2 shows the results of evaluating the electrical conductivity, weight, flexibility, and cross-compressibility of each of the copper-coated aluminum conductor wires produced. For reference, a copper-coated aluminum conductor wire manufactured by the same manufacturing method as the electroplating method described in Patent Document 2 and having an area ratio of the Cu coating layer to the Al core portion of 0.1 (Comparative Example 2-1) ) Was also prepared and is shown in Table 2.

(conductivity)
The electrical conductivity is measured according to JIS H 0505-1975, and the electrical conductivity of the copper-coated aluminum conductor wire when the electrical conductivity of the Cu wire is taken as 100 is shown in Table 2.

(weight)
Table 2 shows the weight of the copper-coated aluminum conductor wire measured by the chemical balance and the weight of the copper-coated aluminum conductor wire when the weight of the Cu wire is 100.

(Flexibility)
Flexibility is determined by bending a copper-coated aluminum conductor wire 180 ° and bending it into a hairpin shape. At that time, the presence or absence of defects such as cracks of 1 mm or more in the hairpin bent portion is observed with an optical microscope or a scanning electron microscope (SEM). Evaluation was made by observation. Table 2 shows the evaluation results of flexibility. “◎” in the column of flexibility shown in Table 2 indicates a case where there is no defect such as a crack in the hairpin bent portion, and “◯” indicates a minute defect of less than 1 mm in the hairpin bent portion. "X" shows the case where defects, such as a crack of 1 mm or more, exist in a hairpin bending part.

(Cross compression)
Cross compressibility is achieved by crossing a copper-coated aluminum conductor wire at 90 ° and pressing the intersecting portion to a position that is half the wire diameter of the wire. At this time, the presence or absence of cracks on the surface of the wire is checked with an optical microscope or Evaluation was made by observing with a scanning electron microscope (SEM). Table 2 shows the evaluation results of the cross-compressibility. “◯” in the column of cross-compressibility shown in Table 2 indicates that cracks are not observed on the surface of the wire, and “x” indicates that cracks are observed on the surface of the wire.

  From the results shown in Table 2, Examples 2-1 to 2-7 were all excellent in flexibility and cross compression. In particular, Examples 2-3 to 2-7 were excellent in flexibility. On the other hand, Comparative Example 2-1 in which the area ratio of the Cu coating layer to the Al core portion was as small as 0.1 was inferior in both flexibility and cross-compressibility.

  According to the present invention, it is possible to provide a copper-coated aluminum conductor wire having a high conductivity that has not been obtained with conventional copper-coated aluminum conductor wires while maintaining a lighter weight than conventional copper wires. It was. Further, according to the present invention, a rod-like copper-coated aluminum composite extruded material in which the thickness of the portion corresponding to the Cu pipe, which could not be produced by the conventional production method, is increased (for example, the copper area ratio is 30% or more). A manufacturing method can be provided. The copper-coated aluminum composite extruded material is suitable for use as a wire drawing material for producing a copper-coated aluminum conductor wire, as well as various kinds of rod-shaped conductive members (for example, bus bars) made of a copper material. If it is used as a substitute for a member, the weight can be reduced. Furthermore, according to the present invention, in particular, it is possible to provide a method for producing a copper-coated aluminum conductor wire that enables the production of a coated aluminum conductor wire having a high area ratio of the Cu coating layer to the Al core described above. In addition to the application to the center line of industrial wires and coaxial cables, it is expected to be applied to a conductor wire used for a minute coil such as a voice coil.

DESCRIPTION OF SYMBOLS 10 Copper covering aluminum conductor wire 11 Al core part 12 Cu coating layer 20 Copper covering aluminum compound extrusion material 21 Al material 22 Cu pipe 23 Composite billet 24 Lid 25 Electron gun (cathode)
26 Press machine 27 Container 28 Dice

Claims (9)

A first step of selecting a cylindrical Cu pipe made of a Cu-based material and a columnar Al material made of an Al-based material so that the ratio of deformation resistance values at 500 ° C. is less than 10, respectively;
Using the selected Cu pipe and the Al material, respectively, a second step of charging the Al material into the Cu pipe;
A third step of forming a composite billet of the Cu pipe in which the Al material is vacuum-sealed by sealing both end openings of the Cu pipe in a state where the inside of the Cu pipe in which the Al material is charged is evacuated;
And a fourth step of obtaining a rod-like copper-coated aluminum composite extruded material obtained by integrating the Al material and the Cu pipe by hot extrusion while heating the composite billet to 400 to 450 ° C. A method for producing a copper-coated aluminum composite extruded material.   The manufacturing method of the copper covering aluminum composite extrusion material of Claim 1 whose ratio of the said deformation resistance value in a said 1st process is 3 or less.   The method for producing a copper-clad aluminum composite extruded material according to claim 1 or 2, further comprising a step of forming a diffusion barrier layer made of Nb or Ta on the surface of the Al material prior to performing the second step.   The manufacturing method of the copper covering aluminum composite extrusion material of any one of Claims 1-3 which makes the area reduction rate at the time of the hot extrusion in the said 4th process 85.0% or more and less than 99.9%.   The ratio of the cross-sectional area of the Cu pipe to the cross-sectional area of the Al material selected in the first step corresponds to the Al material constituting the copper-coated aluminum composite extruded material obtained in the fourth step. The copper-coated aluminum composite extruded material according to any one of claims 1 to 4, wherein a ratio of a cross-sectional area of a portion corresponding to the Cu pipe to a cross-sectional area of the portion to be processed is in a range of 0.43 to 2.30. Manufacturing method.   A copper-coated aluminum composite extruded material produced using the method for producing a copper-coated aluminum composite extruded material according to any one of claims 1 to 5 is subjected to wire drawing to obtain a copper-coated aluminum conductor wire. The manufacturing method of a copper covering aluminum conductor wire including 5 processes.   The ratio of the cross-sectional area of the portion corresponding to the Cu pipe to the cross-sectional area of the portion corresponding to the Al material constituting the copper-coated aluminum composite extruded material obtained in the fourth step is obtained in the fifth step. The copper-coated aluminum composite according to claim 6, wherein the ratio of the cross-sectional area of the Cu coating layer to the cross-sectional area of the Al core constituting the copper-coated aluminum conductor wire is 0.43 to 2.30. Method for producing extruded material. A copper-coated aluminum conductor wire having an Al core portion made of an Al-based material and a Cu coating layer made of a Cu-based material disposed around the Al core portion,
An area ratio of the Cu coating layer to the Al core portion is 0.43 or more when viewed in a cross section of the copper-coated aluminum conductor wire.   The copper-coated aluminum conductor wire according to claim 8, wherein an area ratio of the Cu coating layer to the Al core is 0.82 to 1.23.

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