JP2010280969A - Copper coated aluminum alloy wire - Google Patents

Abstract

An object of the present invention is to provide a copper-coated aluminum wire having flexibility and workability, good drawability, high conductivity and tensile strength.
SO: 0.2 to 0.8% by mass, Fe: 0.36 to 1.5% by mass, Cu: 0.2% by mass or less, Mg: 0.45 to 0.9% by mass, Ti : A copper-coated aluminum alloy wire characterized by comprising a copper coating on an aluminum alloy wire formed of an aluminum alloy containing 0.005 to 0.03% by mass with the balance being Al and inevitable impurities.
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Description

  The present invention relates to a copper-coated aluminum alloy wire in which an aluminum alloy is used as a main conductor and copper is coated on the outer periphery of the main conductor.

  In recent years, wire harnesses for automobile electrical equipment are common and weigh about 25kg / unit, and the electric wire alone accounts for about 15kg / unit. You can't get through. Also, electronic devices are becoming smaller and lighter, and conductors used therein are also required to be lightweight.

  Conventionally, copper has been used as a conductor. However, in order to reduce the weight of conductors, electric wires, and costs required in recent years, as a substitute for copper, the lightness and economy of aluminum, the corrosion resistance of copper, and the conductivity As a conductor that inherits the good parts of both the solderability and the solderability, a copper-coated aluminum wire in which an aluminum wire is coated with copper is used. In general, pure aluminum for electrical use is used as the core aluminum.

  Such a copper-coated aluminum wire has a volume ratio of about 80 to 90%, most of which is aluminum, so the strength and other characteristics of the core aluminum are almost the same as the strength and other characteristics of the copper-coated aluminum wire. It becomes.

  However, the electrical pure aluminum used as the core material has a relatively good electrical conductivity of 61% IACS, but on the other hand, its strength is low and has become a problem.

  Therefore, there are various aluminum alloy standards in JIS as having higher strength than pure electrical aluminum.

  Here, since it is used as a core material of a copper-coated aluminum alloy wire, the aluminum alloy wire of the core material needs flexibility and workability, is highly conductive, and needs to have both tensile strength and elongation. .

  However, an aluminum alloy wire using an aluminum alloy standardized by JIS is difficult to achieve both tensile strength and elongation, has poor drawability and cannot be used as an electric wire, or has a conductivity as low as 50% IACS or less. It could not be used as an electric wire.

  Therefore, improvement of JIS 6000 series aluminum alloys has been proposed (see Patent Documents 1 and 2), and JIS 8000 series aluminum alloys such as JIS 8021 and 8079 are examples of alloys with improved strength and elongation of JIS 1000 series. is there.

Japanese Patent No. 3378819 JP 2000-212664 A

  However, even with the copper-coated aluminum alloy wire using the improved 6000 series Al alloy or the 8000 series aluminum alloy described in the above patent document, the drawability is not good, and both high conductivity and tensile strength are compatible. It was difficult.

  SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a copper-coated aluminum alloy wire that is a copper-coated aluminum wire, has flexibility and workability, has good drawability, is highly conductive, and has tensile strength. To do. Another object of the present invention is to provide an economical conductor that is highly conductive, has good drawability, has tensile strength, and is lightweight.

  The present invention for solving the above problems is as follows: Si: 0.2 to 0.8 mass%, Fe: 0.36 to 1.5 mass%, Mg: 0.45 to 0.9 mass%, Ti: 0 It is a copper-coated aluminum alloy wire characterized by comprising a copper coating on an aluminum alloy wire formed of an aluminum alloy containing 0.005 to 0.03% by mass and the balance being Al and inevitable impurities.

  The aluminum alloy further includes Cu, and is a copper-coated aluminum alloy wire characterized by Cu: 0.2% by mass or less.

  Moreover, it is a conductor characterized by using the said copper covering aluminum alloy wire, A wire harness, a battery cable, etc. are contained as a conductor.

  According to the present invention as described above, it is possible to provide a copper-coated aluminum alloy wire having flexibility and workability, good drawability, high conductivity, and tensile strength. It has become possible. In addition, it has become possible to provide an economical conductor with high conductivity, good drawability, tensile strength, and light weight.

  Embodiments of the present invention will be described below. The copper-coated aluminum alloy wire of the present invention has Si (silicon): 0.2 to 0.8 mass%, Fe (iron): 0.36 to 1.5 mass%, Mg (magnesium): 0.45 to 0 .9% by mass, Ti (titanium): 0.005 to 0.03% by mass, the balance being made of aluminum alloy wire made of Al (aluminum) and inevitable impurities, copper coating was applied Is. Further, the aluminum alloy may further contain Cu in a range of 0.2% by mass or less. The copper-coated aluminum alloy wire of the present invention can be used for various applications, but can be suitably used particularly for automobile conductors, electronic device conductors, and the like.

  The aluminum alloy forming the aluminum alloy wire used as the core material in the present invention contains 0.2 to 0.8 mass% of Si. The Si content is set to 0.2 to 0.8 mass% when the Si content is less than 0.2 mass%, the tensile strength is low, and when the Si content is greater than 0.8 mass%, This is because there is a possibility that cracking or disconnection may occur during the processing.

  The aluminum alloy forming the aluminum wire used as the core material in the present invention contains 0.36 to 1.5% by mass of Fe. The Fe content is set to 0.36 to 1.5% by mass when the Fe content is less than 0.36% by mass, and the tensile strength is low. It is because it falls.

  Moreover, the aluminum alloy which forms the aluminum wire used as a core material by this invention contains 0.45-0.9 mass% of Mg. The Mg content is set to 0.45 to 0.9% by mass when the Mg content is less than 0.45% by mass, the tensile strength is low, and when the Mg content is more than 0.9% by mass, This is because there is a possibility that cracking or disconnection may occur during the processing.

  Moreover, the aluminum alloy which forms the aluminum wire used as a core material in the present invention contains 0.005 to 0.03% by mass of Ti. The Ti content is set to 0.005 to 0.03% by mass when the Ti content is less than 0.005% by mass, and the tensile strength is low. It is because it falls.

  Further, the aluminum alloy forming the aluminum wire used as the core material in the present invention may not contain Cu, but preferably contains it. By containing Cu, the tensile strength can be improved. When it contains Cu, it contains 0.2 mass% or less. The reason why the Cu content is 0.2% by mass or less is that when the Cu content is more than 0.2% by mass, there is a possibility that cracking or disconnection may occur during processing of the conductive wire.

  The balance contains Al and inevitable impurities. Al is desirable to have a high purity in order to improve the conductivity of the conductive wire, and a purity of 99.95% or more is preferable. Moreover, since inevitable impurities cause a decrease in conductivity, it is preferable to reduce the content thereof as much as possible.

  Although the copper coating layer of a copper covering aluminum alloy wire is not specifically limited, It is preferable that the copper covering space ratio which is the area ratio of the copper in the cross-sectional area of copper and aluminum shall be 1-20%. If it is less than 1%, the copper coating layer is easily broken, causing disconnection or connection failure. If it is 20% or more, the aluminum wire of the core material may be easily disconnected at the time of wire drawing. It is.

  The copper tape used in the present invention is preferably a pure copper tape. As an example, an oxygen-free copper tape having an oxygen content of 10 ppm and having a thickness of 0.4 mm and a width of 42 mm can be used. is not.

  Next, the production of the copper-coated aluminum alloy wire of the present invention using the aluminum alloy wire formed with the above composition will be described. First, Si, Fe, Mg, Ti and Al, or further Cu having a composition in the above-described range are dissolved and cast by a continuous casting machine to produce a cast bar. Then, the cast bar is hot-rolled to produce an aluminum alloy wire. Usually, a hot rolling mill is connected to a continuous casting machine in tandem. The wire diameter of the aluminum alloy wire is not particularly limited, but can be about 9.0 to 10.0 mm. In addition, the manufacturing process of an aluminum alloy wire is not limited to the above-mentioned method, Although rolling may be sufficient, other well-known methods, such as extrusion, may be employ | adopted.

  Solution treatment is performed on the aluminum alloy wire. This solution treatment is performed in order to make the additive element form a solid solution, and is preferably performed at 500 to 580 ° C. This is because when the solution treatment is performed at a temperature lower than 500 ° C., the homogenization of the additive element may be insufficient, and when it is higher than 580 ° C., the wire may be partially dissolved. The preferable treatment time is 2 hours 30 minutes to 3 hours 30 minutes, and more preferably 3 hours when the treatment is performed at 550 ° C. After the solution treatment, the wire may be cooled by water cooling or the like, but may not be cooled. This solution treatment may not be performed.

  The copper-coated aluminum alloy wire can be produced by the following two steps using a known method using a known apparatus. The first step is a step of manufacturing a composite wire of a copper-coated aluminum alloy wire by coating copper on an aluminum alloy wire that becomes a core material formed of an aluminum alloy. As a specific example of this step, an aluminum alloy The wire is drawn out from the core material supply device, straightened with a strainer, cleaned with a surface cleaning device, electrolytically degreased, and polished with a brush made of stainless steel or synthetic resin with a polishing device. Further, the copper tape is fed from the copper tape supply device and polished by the polishing device.

  Then, using the pipe making method, the polished aluminum alloy wire and copper tape are introduced into the molding device, and the aluminum tape is vertically attached to the copper tape with the molding device, and the copper tape is made of aluminum so as to cover the aluminum alloy wire It is continuously formed into a tubular shape on the alloy wire, the butt portion of the copper tape is continuously welded by a TIG (tungsten inner gas) method, and the copper tape that has been formed and welded into a tubular shape is reduced in diameter by a roll. Then, it is brought into intimate contact with the core aluminum alloy wire and wound on a winder.

  In the second step, the composite wire of the copper-coated aluminum alloy wire obtained in the first step is drawn by cold working using a known wire drawing machine, and the copper wire is thinned to a predetermined diameter to obtain a copper wire. This is a process for forming a coated aluminum alloy wire. In this process, a die having a predetermined surface reduction rate, for example, a surface reduction rate of 10 to 30% is used, and the composite wire of the copper-coated aluminum alloy wire is gradually thinned, and the copper tape and the aluminum wire are completely formed. Adhering to each other, a copper-coated aluminum alloy wire is formed. The wire drawing may not be cold working.

  The copper-coated aluminum alloy wire produced in this manner is, for example, a twisted wire formed by twisting a plurality of wires, a twisted wire obtained by further bringing a plurality of twisted wires together, or a compression obtained by compressing these twisted wires into a circle It can be used as a conductor, and these stranded wires and compressed conductors are subjected to known processing such as covering with a synthetic resin to form conductors such as wire harnesses and battery cables.

  Si, Fe, Cu, Mg, Ti, and Al are dissolved in the composition shown in Table 1, and cast with a continuous casting machine to produce a cast bar with a wire diameter of 25 mm. The cast bar is hot-rolled to obtain a wire diameter of 9 A 5 mm aluminum alloy wire was prepared and subjected to a solution treatment at 550 ° C. for 3 hours. After this solution treatment, the aluminum alloy wire was cooled by water cooling, and an oxygen-free oxygen layer having a thickness of 0.4 mm and an oxygen content of 10 ppm. After forming a composite wire of a copper-coated aluminum wire having a copper-covered space ratio of 15% using the above-described process using a copper tape, it is cooled by a wire drawing machine using a die having a surface reduction rate of 15 to 30%. Wire drawing was performed to form a copper-coated aluminum alloy wire having a wire diameter of 0.2 mm.

  As a characteristic evaluation of the copper-coated aluminum alloy wire thus produced, a tensile test at 20 ° C. and a conductivity measurement at 20 ° C. were performed in accordance with JISC3002. The results are shown in Table 1. In the judgment, a material satisfying both of a tensile strength of 500 MPa or more and a conductivity of 60% IACS or more is regarded as acceptable (indicated by “◯” in the table), and a material not satisfying at least one is rejected (“×” in the table). It was shown.)

  As shown in Examples 1 to 10, the copper-coated aluminum alloy wire of the present invention satisfied the conditions that the tensile strength was 500 MPa or more and the conductivity was 60% IACS or more, and the determination was acceptable. On the other hand, as shown in Comparative Examples 1 to 14, the copper-coated aluminum alloy wire that does not satisfy the conditions of the present invention does not reach either the target value or the tensile strength, conductivity, or cracks during processing. However, the judgment was unacceptable. The aluminum alloy of Comparative Example 1 is JIS1100, the aluminum alloy of Comparative Example 2 is JIS2017, the aluminum alloy of Comparative Example 3 is JIS3003, the aluminum alloy of Comparative Example 4 is JIS4032, and The aluminum alloy is JIS5052, the aluminum alloy of Comparative Example 6 is JIS6063, and the aluminum alloy of Comparative Example 7 is JIS7075.

  The copper-coated aluminum alloy wire of the present invention can reduce the weight of the conductive wire and reduce the cost. Further, it has flexibility and workability, is highly conductive, and has both tensile strength and elongation. It can be used suitably for conductors such as conductors for automobiles and conductors for electronic devices.

Claims (3)

  Si: 0.2-0.8% by mass, Fe: 0.36-1.5% by mass, Mg: 0.45-0.9% by mass, Ti: 0.005-0.03% by mass, A copper-coated aluminum alloy wire characterized in that a copper coating is applied to an aluminum alloy wire formed of an aluminum alloy consisting of Al and inevitable impurities.   The aluminum alloy wire further includes Cu, and Cu: 0.2% by mass or less.   A conductor formed using the copper-coated aluminum alloy wire according to claim 1.