JP5247584B2 - Al alloy and Al alloy conductive wire - Google Patents

Description

  The present invention relates to an Al alloy conductive wire suitably used for a conductor such as a wire harness or a battery cable.

  Conventionally, Cu has been used for conductive wires, but in recent years, pure Al or Al alloys have been proposed as an alternative to Cu in order to reduce the weight of conductive wires and reduce costs. Since high-strength and high-conductivity conductive wires are required, JIS 1000 series or 6000 series Al alloys are used.

  Here, since it is used as a conductive wire, the Al alloy conductive wire needs flexibility and workability, is highly conductive, and requires both tensile strength and elongation.

  However, in a conductive wire using a JIS 1000 or 6000 series Al alloy, the electrical conductivity may be satisfied, but it is difficult to achieve both tensile strength and elongation.

  Therefore, improvement of JIS 6000 series Al alloy has been proposed (see Patent Documents 1 and 2), and JIS 8000 series Al alloy, such as JIS There are 8021 and 8079.

Japanese Patent No. 3378819 JP 2000-212664 A

  However, even with the conductive wire using the improved 6000 series Al alloy or the 8000 series Al alloy described in the above patent document, it is difficult to achieve both tensile strength and elongation.

  Therefore, the present invention is an Al alloy for forming a conductive wire, and the conductive wire formed of the Al alloy has flexibility and workability, is highly conductive, and has both tensile strength and elongation. An object is to provide an Al alloy and to provide a conductive wire and a conductor using the Al alloy.

  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 0.005 to 0.03% by mass, and the balance is made of Al and inevitable impurities.

  Further, the Al alloy further includes Cu and is Cu: 0.2% by mass or less.

  Moreover, it is an Al alloy conductive wire characterized by being formed of the above Al alloy. The Al alloy conductive wire is preferably formed by performing a tempering treatment of any one of JIS T5, JIS T6, JIS T8 or JIS T10.

  Furthermore, it is a conductor formed by using the Al alloy conductive wire, and includes a wire harness, a battery cable, and the like as the conductor.

  According to the present invention as described above, a conductive wire using an Al alloy is provided with an Al alloy and an Al alloy conductive wire having flexibility and workability, high conductivity, and having both tensile strength and elongation. Became possible. In addition, it is possible to provide an Al alloy conductor that has flexibility and workability, is highly conductive, and has both tensile strength and elongation in a conductive wire using an Al alloy.

  Embodiments of the present invention will be described below. The Al alloy 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 mass% %, Ti (titanium): 0.005 to 0.03 mass%, and the balance is made of Al (aluminum) and inevitable impurities. Further, the Al alloy of the present invention may further contain Cu in the range of 0.2% by mass or less. Although the Al alloy of the present invention can be used for various applications, it can be suitably used particularly for conductive wires.

  The Al alloy of the present invention contains 0.2 to 0.8 mass% of Si. The Si content is set to 0.2 to 0.8% by mass. If the Si content is less than 0.2% by mass, the tensile strength and the elongation cannot be compatible, and the Si content is more than 0.8% by mass. This is because there is a possibility that breakage or disconnection may occur during processing of the conductive wire.

  The Al alloy of the present invention contains 0.36 to 1.5% by mass of Fe. The reason why the Fe content is 0.36 to 1.5% by mass is that when the Fe content is less than 0.36% by mass, both the tensile strength and the elongation cannot be achieved, and the Fe content is more than 1.5% by mass. This is because the conductivity decreases.

  The Al alloy of the present invention contains 0.45 to 0.9% by mass of Mg. The reason why the Mg content is 0.45 to 0.9% by mass is that when the Mg content is less than 0.45% by mass, both the tensile strength and the elongation cannot be achieved, and the content is more than 0.9% by mass. This is because there is a possibility that breakage or disconnection may occur during processing of the conductive wire.

  The Al alloy of the present invention contains 0.005 to 0.03% by mass of Ti. The content of Ti is set to 0.005 to 0.03% by mass. When the content of Ti is less than 0.005% by mass, it is impossible to achieve both tensile strength and elongation, and the content is more than 0.03% by mass. This is because the conductivity decreases.

  Moreover, although Al alloy of this invention does not need to contain Cu, it is preferable to contain. 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.

  Next, production of the Al alloy conductive wire of the present invention using the above-described Al alloy of the present invention 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. And a cast rod is hot-rolled and a wire rod is produced. Usually, a hot rolling mill is connected to a continuous casting machine in tandem. The wire diameter of the wire rod is not particularly limited, but can be about 9.0 to 10.0 mm.

  This wire rod is cold drawn, drawn to a wire diameter of about 5.0 to 6.0 mm, and then subjected to a solution treatment. This solution treatment is performed in order to dissolve the added elements uniformly and in a large amount, and is preferably performed at 500 to 580 ° C. When the solution treatment is performed at a temperature lower than 500 ° C., the amount of solid solution is small, and the homogenization of the additive element may be insufficient. When the temperature is higher than 580 ° C., the wire may be partially dissolved. Because there is. The preferable treatment time is 2 hours 30 minutes to 3 hours 30 minutes, more preferably 3 hours when the treatment is performed at 550 ° C. After the solution treatment, the wire is preferably water cooled. This is because, by this water cooling, it is possible to keep a large amount of added elements in a solid solution state, and when water cooling is not performed, the solid solution elements are precipitated during cooling.

  Next, cold drawing is further performed to produce a strand having a desired wire diameter. The wire diameter of the strand is usually about 0.3 to 0.4 mm.

Then, age hardening is performed. This age hardening treatment is a treatment for finely precipitating additive elements that are excessively dissolved in solid solution. By this age hardening treatment, Mg ₂ Si is precipitated. This age hardening treatment is preferably performed at 200 to 250 ° C. This is because if the age hardening treatment is performed at a temperature lower than 200 ° C., the precipitation is insufficient, and if the age hardening treatment is performed at a temperature higher than 250 ° C., coarse particles are precipitated. In addition, as preferable age hardening processing time, it is 2 hours 30 minutes-3 hours 30 minutes, More preferably, it is 3 hours.

  In addition, the manufacturing process of the Al alloy conductive wire is not limited to the above-described method, and may be rolling, but may be extrusion, and the wire drawing may not be cold working. In particular, the tempering process is not particularly limited, but in order to further increase the tensile strength, elongation and conductivity, cold working is performed after solution treatment, and further artificial Method of applying age hardening treatment (JIS T8), Method of applying artificial age hardening treatment without performing cold working after solution treatment (JIS T6), Cold working after cooling from high temperature processing, and further artificial age hardening treatment (JIS T10) and a method of applying an artificial age hardening treatment without performing cold working after cooling from high temperature processing (JIS T5) are preferable.

  The conductive wire thus produced can be used, for example, as a compressed conductor in which a plurality of twisted wires are twisted together, a twisted wire in which a plurality of twisted wires are further twisted, or these twisted wires are compressed into a circular shape. These twisted wires and compressed conductors can be processed such as covering with a synthetic resin to form a conductor such as a wire harness or a battery cable.

Si, Fe, Cu, Mg, Ti and Al were melted with 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 was hot-rolled to obtain a wire diameter of 9 A 5 mm wire rod was manufactured, the wire rod was cold drawn, the wire diameter was drawn to 5.5 mm, and solution treatment was performed at 550 ° C. for 3 hours. Was cooled with water and further cold drawn to 0.33 mm. The Al alloy wire was subjected to aging treatment for 3 hours at 200 to 250 ° C..

As an evaluation of the characteristics of the Al alloy conductive 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. As for the judgment, those satisfying all of the tensile strength of 140 MPa or more, the elongation of 10% or more, and the conductivity of 55% IACS or more are acceptable (indicated by “◯” in the table), and those that do not satisfy even one It was determined to be rejected (indicated by “x” in the table). Here, the tensile strength of 140 MPa or higher was accepted, and the tensile strength for realizing the tensile strength equivalent to that of an annealed copper wire (about 210 MPa) with an Al alloy wire having a cross-sectional area of 1.5 times was 210 MPa. This is because × 2/3 = 140 MPa. Even when the cross-sectional area is 1.5 times, the density of aluminum is 2.7 g / cm ³ and the density of copper is 8.9 g / cm ^3, so the weight can be reduced.

  As shown in Examples 1 to 12, the Al alloy conductive wire of the present invention satisfies all of the tensile strength of 140 MPa or more, the elongation of 10% or more, and the conductivity of 55% IACS or more. there were. On the other hand, as shown in Comparative Examples 1 to 16, an Al alloy conductive wire that does not satisfy the conditions of the present invention does not reach any of the target values of tensile strength, elongation, or conductivity, or cracks occur during processing. However, the judgment was unacceptable. In the comparative example, when the age hardening treatment temperature is high, the elongation is improved, but the tensile strength is lowered, and when the age hardening treatment temperature is low, the tensile strength is improved, but the elongation is lowered. In the examples, the tensile strength and the elongation reach the target values regardless of the temperature of the age hardening treatment. The Al alloys of Comparative Examples 1 and 2 are JIS6063, the Al alloys of Comparative Examples 3 and 4 are those described in Patent Document 1, and the Al alloys of Comparative Examples 5 and 6 are described in Patent Document 2. The described alloy.

  The Al alloy of the present invention can reduce the weight of the conductive wire and reduce the cost, and further has flexibility and workability, is highly conductive, and has both tensile strength and elongation. Furthermore, the Al alloy conductive wire formed of the Al alloy of the present invention can be suitably used for a conductor such as a wire harness or a battery cable.

Claims (4)

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, An Al alloy conductive wire, wherein the balance is an Al alloy composed of Al and inevitable impurities, and is formed by heat treatment at 200 to 250 ° C. for 2.5 to 3.5 hours. The Al alloy conductive wire according to claim 1, wherein the Al alloy further contains Cu, and Cu: 0.2% by mass or less.
3. The Al alloy conductive wire according to claim 1, wherein the Al alloy conductive wire is formed by performing a tempering treatment of either JIS T8 or JIS T10.
A conductor formed using the Al alloy conductive wire according to any one of claims 1 to 3.