JP5846360B2 - Aluminum alloy conductor - Google Patents

Description

  The present invention relates to an aluminum alloy conductor used as a conductor of an electric wiring body.

2. Description of the Related Art Conventionally, a member in which a terminal (connector) made of copper or copper alloy (for example, brass) is attached to an electric wire including a copper or copper alloy conductor called a wire harness as an electric wiring body of a moving body such as an automobile, a train, and an aircraft However, in light of the recent weight savings of moving bodies, studies are underway to use aluminum or aluminum alloys that are lighter than copper or copper alloys as conductors of electrical wiring bodies.
The specific gravity of aluminum is about 1/3 of copper, and the electrical conductivity of aluminum is about 2/3 of copper (pure aluminum is about 66% IACS when pure copper is used as the standard of 100% IACS). In order to pass the same current as that of a pure copper conductor wire, the cross-sectional area of the pure aluminum conductor wire needs to be about 1.5 times that of the pure copper conductor wire, but the mass is still about half that of copper. Therefore, there is an advantage.
In addition, said% IACS expresses the electrical conductivity when the resistivity 1.7241 × 10 ⁻⁸ Ωm of universal standard annealed copper (International Annealed Copper Standard) is 100% IACS.

There are some problems in using the aluminum as a conductor of the electric wiring body of the moving body. One of them is improvement of bending fatigue resistance. This is because a wire harness attached to a door or the like is repeatedly subjected to bending stress by opening and closing the door. When a metal material such as aluminum is repeatedly applied and removed as when the door is opened and closed, it breaks at a certain number of repetitions (fatigue failure) even at a low load that does not break at a single load. When the aluminum conductor is used for an opening / closing part, if the bending fatigue resistance is poor, there is a concern that the conductor breaks during use, and durability and reliability are lacking.
Generally, it is said that a material having higher strength has better fatigue characteristics. Therefore, high-strength aluminum wire may be applied, but the wire harness is required to be easy to handle (installation work on the vehicle body) at the time of installation, so generally the elongation is 10% or more. In many cases, a dull material (annealed material) that can be secured is used.

  Therefore, the aluminum conductor used for the electric wiring body of the moving body has an appropriate tensile strength required for handling and installation, and conductivity required for flowing a large amount of electricity, as well as resistance to bending fatigue. There is a need for flexible materials that are excellent and easy to handle.

  For such demanding applications, pure aluminum systems such as power transmission line aluminum alloy wires (JIS A1060 and JIS A1070) cannot sufficiently withstand repeated bending stresses that occur when doors are opened and closed. Moreover, although the material alloyed by adding various additive elements is excellent in strength, it causes a decrease in conductivity due to a solid solution phenomenon of the additive element in aluminum, and forms an excessive intermetallic compound in aluminum. As a result, disconnection due to the intermetallic compound may occur during wire drawing. For this reason, it is essential to limit and select the additive element and not to disconnect, to prevent a decrease in conductivity, and to improve strength and bending fatigue resistance.

  Patent Documents 1 and 2 include typical aluminum conductors used for electric wiring bodies of moving bodies. However, the electric wire conductor described in Patent Document 1 has too high tensile strength, and is difficult to mount on the vehicle body. Patent Document 2 discloses an aluminum conductive wire that is lightweight, flexible, and excellent in bendability. However, the demand for improving the characteristics of the electric wiring body of the moving body is intensifying, and further improvement of the characteristics is desired. Yes.

JP 2008-112620 A JP 2006-253109 A

  An object of this invention is to provide the aluminum alloy conductor which has sufficient tensile strength and electrical conductivity, and was excellent in bending fatigue resistance and flexibility.

  The inventors have made various studies and controlled the crystal orientation by controlling the heat treatment conditions such as the wire drawing condition before the heat treatment of the aluminum alloy and the continuous heat treatment, and has excellent strength, conductivity, bending fatigue resistance, In addition, the present inventors have found that an aluminum alloy conductor having flexibility can be produced, and have completed the present invention based on this finding.

That is, the said subject was achieved by the following invention.
(1) Fe of 0.01 to 0.4 mass%, Mg of 0.01 mass% to less than 0.3 mass%, Si of 0.01 mass% to less than 0.3 mass%, and Cu of 0.01 to 0 An aluminum alloy conductor containing the balance Al and inevitable impurities,
Area of crystal grains having a plane inclined at an angle within the range of a standard triangle of a stereo projection view by 25 ° or more from the (111) plane positioned parallel to the cross section perpendicular to the wire drawing direction of the wire. When the radius of the wire is R, the rate is 50% or more in a circle of radius (3/10) R from the center of the wire, and is located parallel to the cross section perpendicular to the wire drawing direction (111). ) The area ratio of crystal grains having a surface inclined in the range of 0 ° or more and less than 25 ° with respect to the normal direction from the surface is excluded from the entire wire rod within a circle of radius (7/10) R from the center of the wire rod An aluminum alloy conductor characterized by being 50% or more in the above range.
(2) An aluminum alloy conductor containing 0.4 to 1.5 mass% of Fe, and comprising the balance Al and inevitable impurities,
Area of crystal grains having a plane inclined at an angle within the range of a standard triangle of a stereo projection view by 25 ° or more from the (111) plane positioned parallel to the cross section perpendicular to the wire drawing direction of the wire. When the radius of the wire is R, the rate is 50% or more in a circle of radius (3/10) R from the center of the wire, and is located parallel to the cross section perpendicular to the wire drawing direction (111). ) The area ratio of crystal grains having a surface inclined in the range of 0 ° or more and less than 25 ° with respect to the normal direction from the surface is excluded from the entire wire rod within a circle of radius (7/10) R from the center of the wire rod An aluminum alloy conductor characterized by being 50% or more in the above range.
(3) Aluminum containing Fe of 0.4 to 1.5 mass%, Mg of 0.01 to 0.3 mass%, Si of 0.01 to 0.3 mass%, the balance being Al and inevitable impurities An alloy conductor,
Area of crystal grains having a plane inclined at an angle within the range of a standard triangle of a stereo projection view by 25 ° or more from the (111) plane positioned parallel to the cross section perpendicular to the wire drawing direction of the wire. When the radius of the wire is R, the rate is 50% or more in a circle of radius (3/10) R from the center of the wire, and is located parallel to the cross section perpendicular to the wire drawing direction (111). ) The area ratio of crystal grains having a surface inclined in the range of 0 ° or more and less than 25 ° with respect to the normal direction from the surface is excluded from the entire wire rod within a circle of radius (7/10) R from the center of the wire rod An aluminum alloy conductor characterized by being 50% or more in the above range.
(4) 0.01-1.5 mass% Fe, 0.3-1.0 mass% Mg, 0.3-1.0 mass% Si, 0.01-0.5 mass% Cu An aluminum alloy conductor comprising the balance Al and inevitable impurities,
Area of crystal grains having a plane inclined at an angle within the range of a standard triangle of a stereo projection view by 25 ° or more from the (111) plane positioned parallel to the cross section perpendicular to the wire drawing direction of the wire. When the radius of the wire is R, the rate is 50% or more in a circle of radius (3/10) R from the center of the wire, and is located parallel to the cross section perpendicular to the wire drawing direction (111). ) The area ratio of crystal grains having a surface inclined in the range of 0 ° or more and less than 25 ° with respect to the normal direction from the surface is excluded from the entire wire rod within a circle of radius (7/10) R from the center of the wire rod An aluminum alloy conductor characterized by being 50% or more in the above range.
( 5 ) The area ratio of crystal grains having a plane inclined in a range of 0 ° or more and 20 ° or less with respect to the normal direction from the (100) plane positioned parallel to the cross section perpendicular to the drawing direction of the wire, The aluminum alloy according to any one of (1) to (4), wherein the radius of the wire is R and is 50% or more in a circle of radius (3/10) R from the center of the wire conductor.
( 6 ) The area ratio of the crystal grains having a plane inclined in a range of 0 ° or more and less than 10 ° with respect to the normal direction from the (111) plane positioned parallel to the cross section perpendicular to the drawing direction of the wire, Any one of (1) to (5), wherein the radius of the wire is R and is 50% or more in the range excluding the inside of the circle of radius (7/10) R from the center of the wire from the whole wire 2. The aluminum alloy conductor according to item 1 .
( 7 ) The area ratio of crystal grains having a plane inclined in a range of 10 ° or more and less than 25 ° with respect to the normal direction from the (111) plane positioned parallel to the cross section perpendicular to the drawing direction of the wire, Any one of (1) to (5), wherein the radius of the wire is R and is 50% or more in the range excluding the inside of the circle of radius (7/10) R from the center of the wire from the whole wire 2. The aluminum alloy conductor according to item 1 .
(8 ) The aluminum alloy conductor according to any one of (1) to ( 7 ), wherein the aluminum alloy conductor is used as a battery cable, a harness, or a conductor for a motor in a moving body.
( 9 ) The aluminum alloy conductor according to ( 8 ), wherein the moving body is an automobile, a train, or an aircraft.

  The aluminum alloy conductor of the present invention is excellent in strength, flexibility, and electrical conductivity, and is useful as a battery cable, harness, or motor lead wire mounted on a moving body. Examples of the moving body include automobiles, train vehicles, and aircraft. It can also be suitably used for doors, trunks, bonnets and the like that require extremely high bending fatigue resistance.

It is explanatory drawing of the circle | round | yen of radius (3/10) R and radius (7/10) R from the center of a circle | round | yen in the cross section perpendicular | vertical to the wire drawing direction of a wire. It is explanatory drawing of a die angle. It is explanatory drawing of the test which measures the frequency | count of repeated fracture | rupture performed in the Example. It is a figure showing the range of the standard triangle of a (111) stereo projection figure.

  The aluminum alloy conductor of the present invention can have excellent tensile strength, electrical conductivity, bending fatigue resistance, and flexibility by defining the crystal orientation as follows.

In the present invention, the crystal orientation is defined using a cross section perpendicular to the drawing direction of the wire. The crystal orientation represents which direction the crystal axis is oriented with respect to the sample axis. In the present invention, the sample axis is described using a surface positioned parallel to the cross section perpendicular to the drawing direction of the wire.
The first aluminum alloy conductor of the present invention has a predetermined alloy composition described later, and is stereo at 25 ° or more with respect to the normal direction from the (111) plane located parallel to the cross section perpendicular to the wire drawing direction of the wire. The area ratio of crystal grains having a surface inclined at an angle within the range of the standard triangle in the projected view is 50% or more in a circle of radius (3/10) R from the center of the wire, where R is the radius of the wire. And an area ratio of crystal grains having a plane inclined in a range of 0 ° or more and less than 25 ° with respect to the normal direction from the (111) plane positioned parallel to the cross section perpendicular to the wire drawing direction of the wire Is 50% or more in the range excluding the inside of the circle of radius (7/10) R from the center of the wire from the whole wire. With such a recrystallized texture, when the wire is bent as shown in FIG. 3 with respect to the wire drawing direction, the bending fatigue resistance can be improved due to the difference in crystal orientation between the inside and outside of the wire. The ease of cross-sliding affects the bending fatigue resistance, and there are many (100) planes that are easy to cross-slip in a circle with a radius (3/10) R from the center of the wire. It is considered that it is better that more (111) planes, which are difficult to cross-slip, appear in the range excluding the circle of radius (7/10) R from the center of the wire than the entire wire. A crossing slip is a slip that changes from one slip surface to another. Area of crystal grains having a plane inclined at an angle within the range of a standard triangle of a stereo projection view by 25 ° or more from the (111) plane positioned parallel to the cross section perpendicular to the wire drawing direction of the wire. The rate is preferably 60% or more, and more preferably 70% or more, within a circle having a radius (3/10) R from the center of the wire. The area ratio of crystal grains having a plane inclined in a range of 0 ° or more and less than 25 ° with respect to the normal direction from the (111) plane positioned parallel to the cross section perpendicular to the wire drawing direction is greater than that of the whole wire. It is preferably 60% or more, more preferably 70% or more, in a range excluding the inside of a circle having a radius (7/10) R from the center of the wire.

Here, the angle within the range of the standard triangle in the stereo projection view will be described. FIG. 4 is a diagram showing the range of the standard triangle in the (111) stereo projection view. In this circle, there are many triangles surrounded by <001>, <011>, and <111>, and the crystal orientation in this circle can be represented by one triangle in consideration of the crystal property. Therefore, the standard triangle 41 is taken out from the one near the center. Since this is a projection, the vertices of this triangle may be connected by a curve. Note that a cubic crystal was considered because the alloy is mainly composed of aluminum.
Considering that an equivalent plane appears when a certain crystal plane is tilted at a certain angle, the tilt angle falls within the angle of the standard triangle in the stereographic projection. For example, since the (120) plane inclined by 39.2 ° and the (−120) plane inclined by 75.0 ° can be represented as equivalent planes with respect to the normal direction of the (111) plane, the standard triangle of the stereo projection view It is better to describe at 39.2 ° within the range. These equivalent planes can be represented as one group using the symbol {120}.
That is, the inclination angle θ is an angle within the range of 0 ≦ θ ≦ standard triangle, but the maximum inclination angle differs depending on the crystal plane of interest. Further, for example, even if the (111) plane is the target, the maximum value of the range of the standard triangle is not necessarily determined, and differs depending on which direction the (111) plane is inclined with respect to the normal direction. In addition, the maximum value of the range of the standard triangle on the (111) plane is 54.7 ° when inclined to the (100) plane.

  In addition to the first aluminum alloy conductor, the second aluminum alloy conductor of the present invention is 0 ° or more and 20 ° on the basis of the normal direction from the (100) plane located parallel to the cross section perpendicular to the wire drawing direction of the wire. The area ratio of crystal grains having inclined surfaces in the following ranges is 50% or more in a circle of radius (3/10) R from the center of the wire, where R is the radius of the wire. . The area ratio of crystal grains having a plane inclined in the range of 0 ° or more and 20 ° or less with respect to the normal direction from the (100) plane positioned parallel to the cross section perpendicular to the wire drawing direction is the center of the wire From within a circle of radius (3/10) R, preferably 60% or more, more preferably 70% or more.

  In addition to the first or second aluminum alloy conductor, the third aluminum alloy conductor of the present invention is 0 ° with respect to the normal direction from the (111) plane positioned parallel to the cross section perpendicular to the wire drawing direction of the wire. When the radius of the wire is R, the area ratio of the crystal grains having the inclined surface in the range of less than 10 ° is within the range excluding the inside of the circle with the radius (7/10) R from the center of the wire. It is characterized by being 50% or more. The area ratio of crystal grains having a plane inclined in a range of 0 ° or more and less than 10 ° with respect to the normal direction from the (111) plane positioned parallel to the cross section perpendicular to the drawing direction of the wire is greater than the entire wire. It is preferably 60% or more, more preferably 70% or more, in a range excluding the inside of a circle having a radius (7/10) R from the center of the wire.

  In addition to the first or second aluminum alloy conductor, the fourth aluminum alloy conductor of the present invention is 10 ° from the (111) plane located parallel to the cross section perpendicular to the wire drawing direction of the wire, with reference to the normal direction. When the radius of the wire is R, the area ratio of the crystal grains having the inclined surface in the range of less than 25 ° is within the range excluding the inside of the circle with the radius (7/10) R from the center of the wire. It is characterized by being 50% or more. A crystal grain having a plane inclined from the (111) plane located parallel to the cross section perpendicular to the wire drawing direction of the wire in the range of 10 ° or more and less than 25 ° with respect to the normal direction intersects the (111) plane. It is easy to slip, but it is harder to cross than the (100) plane. The area ratio of crystal grains having a plane inclined in the range of 10 ° or more and less than 25 ° with respect to the normal direction from the (111) plane positioned parallel to the cross section perpendicular to the wire drawing direction is more than the whole wire. It is preferably 60% or more and more preferably 70% or more in a range excluding the inside of a circle having a radius (7/10) R from the center of the wire.

  A plane tilted in a range of 0 ° or more and less than 25 ° with respect to the normal direction from the (111) plane positioned parallel to the cross section perpendicular to the drawing direction of the wire is expressed as (111) Plane, (112) plane, (122) plane, (123) plane, (133) plane, (223) plane, (233) plane, and the like. A plane inclined from the (111) plane located parallel to the cross section perpendicular to the wire drawing direction of the wire within a standard triangle range of 25 ° or more with respect to the normal direction as a reference is represented by a crystal orientation. , (100) plane, (110) plane, (120) plane, (130) plane, (113) plane, and the like. The surfaces inclined in the range of 0 ° or more and 20 ° or less with respect to the normal direction from the (100) surface positioned parallel to the cross section perpendicular to the wire drawing direction are the (100) surface and the (410) surface. , (411) plane and the like. The surfaces inclined in the range of 0 ° or more and less than 10 ° with respect to the normal direction from the (111) surface positioned parallel to the cross section perpendicular to the wire drawing direction are the (111) surface and the (334) surface. , (344) plane and the like. The surfaces inclined in the range of 10 ° or more and less than 25 ° with respect to the normal direction from the (111) surface located parallel to the cross section perpendicular to the wire drawing direction are the (112) surface and the (122) surface. , (123) plane, (133) plane, (223) plane, (233) plane, and the like.

The area ratio of crystal grains having each crystal orientation in the present invention is a value measured by the EBSD method. The EBSD method is an abbreviation for Electron BackScatter Diffraction, and is a crystal orientation analysis technique using reflected electron Kikuchi line diffraction that occurs when a sample is irradiated with an electron beam in a scanning electron microscope (SEM). The information obtained in the azimuth analysis by EBSD includes azimuth information up to a depth of several tens of nanometers at which the electron beam penetrates the sample, but is sufficiently small with respect to the measured width. Let us treat it as an area ratio.

  An aluminum alloy conductor having such a crystal orientation can be obtained by controlling the production conditions of the aluminum alloy conductor as follows, and more preferably by setting the alloy composition as described below. Preferred manufacturing methods and alloy compositions are described below.

(Production method)
The aluminum alloy conductor of the present invention includes [1] melting, [2] casting, [3] hot or cold processing (groove roll processing, etc.), [4] wire drawing, [5] heat treatment (intermediate annealing), It can be manufactured through steps of [6] wire drawing and [7] heat treatment (finish annealing).

  Melting is carried out in an amount so as to be the concentration of each embodiment of the aluminum alloy composition described later.

  Next, rolling is performed while continuously casting the molten metal in a water-cooled mold using a Properti-type continuous casting and rolling machine in which a cast wheel and a belt are combined to obtain a bar of about 10 mmφ. The casting cooling rate at this time is 1 to 20 ° C./second. Casting and hot rolling may be performed by billet casting, extrusion, or the like.

Next, the surface is peeled to 9 to 9.5 mmφ, and this is drawn. The degree of processing is preferably 1 or more and 6 or less. Here, the processing degree η is η = ln, where A _{0 is} a cross-sectional area perpendicular to the wire drawing direction of the wire before wire drawing, and A ₁ is a cross-sectional area perpendicular to the wire drawing direction of the wire after wire drawing. It is represented by (A ₀ / A ₁ ). If the degree of work at this time is too small, the recrystallized grains become coarse during the heat treatment in the next step, and the strength and elongation are remarkably lowered, which may cause disconnection. If it is too large, the wire drawing process becomes difficult, and there may be a problem in terms of quality such as disconnection during the wire drawing process. Although the surface is cleaned by carrying out the peeling of the surface, it may not be carried out.

  Intermediate annealing is applied to the cold-drawn workpiece. The intermediate annealing is performed mainly to regain the flexibility of the wire that has been hardened by wire drawing. If the intermediate annealing temperature is too high or too low, the wire is broken in the subsequent wire drawing process, and the wire cannot be obtained. The intermediate annealing temperature is preferably 300 to 450 ° C, more preferably 350 to 450 ° C. The time for the intermediate annealing is 10 minutes or more. If it is less than 10 minutes, the time required for the formation and growth of recrystallized grains is insufficient, and the flexibility of the wire cannot be recovered. Preferably it is 1 to 6 hours. The average cooling rate from the heat treatment temperature during intermediate annealing to 100 ° C. is not particularly specified, but is preferably 0.1 to 10 ° C./min.

Further, the wire drawing is preferably performed to an arbitrary wire diameter of 0.15 mmφ to 1.0 mmφ. During the wire drawing process, before the wire becomes hard and frequently breaks, the heat treatment process as described above may be appropriately softened.
In the aluminum alloy conductor of the present invention, wire drawing is performed by die drawing so that the cross-sectional reduction rate of one die is 10% or more and the die half angle is 5 ° or more. The cross-sectional reduction rate is given as the difference between the cross-sectional areas perpendicular to the drawing direction before and after the drawing process divided by the cross-sectional area before the drawing process and multiplied by 100. The die half angle is an angle when the conductor is drawn into the die as shown in FIG. In FIG. 2, the die half angle 22 of the die 21 is indicated by α. If one or both of the cross-section reduction rate and the die half-angle of one die are less than the specified value, the shear stress applied to the material is insufficient, and the die is positioned parallel to the cross-section perpendicular to the wire drawing direction (111 ) The area ratio of the crystal grains having a surface inclined at an angle within the range of the standard triangle of the stereo projection 25 ° or more with respect to the normal direction from the surface is a circle having a radius (3/10) R from the center of the wire. And a crystal grain having a plane inclined within a range of 0 ° or more and less than 25 ° with respect to the normal direction from the (111) plane positioned parallel to the cross section perpendicular to the drawing direction of the wire. May not be 50% or more in the range excluding the inside of the circle of radius (7/10) R from the center of the wire to the entire wire. As the cross-sectional reduction rate and the die angle of one die are higher, the shear stress to be applied is increased, so that the crystal orientation is more different in and out of the wire, and the circle of radius (3/10) R from the center of the wire. The area ratio of crystal grains having a plane inclined in the range of 0 ° to 20 ° with respect to the normal direction from the (100) plane positioned parallel to the cross section perpendicular to the drawing direction of the wire is increased. Or from the center of the wire to the range excluding the circle with a radius (7/10) R from the center of the wire, with reference to the normal direction from the (111) plane located parallel to the cross section perpendicular to the wire drawing direction. The area ratio of crystal grains having a plane inclined in the range of 0 ° or more and less than 25 ° may increase. In particular, the area ratio of crystal grains having a plane inclined in a range of 0 ° or more and less than 10 ° with respect to the normal direction from the (111) plane positioned parallel to the cross section perpendicular to the wire drawing direction of the wire increases. The cross-sectional reduction rate of one die is preferably 12% or more, and more preferably 15% or more. If the cross-section reduction rate of one die is too large, the pulling force becomes excessive, and there is a high possibility that disconnection or line roughness will occur. Therefore, it is preferably within 30%. The die half angle is preferably 7 ° or more, and more preferably 9 ° or more. If the die half angle is too large, the shear stress applied to the wire becomes excessive, and there is a high possibility that disconnection or wire roughening will occur. Therefore, it is preferably 15 ° or less.

  Finish annealing is performed on the cold-drawn workpiece by continuous heat treatment. The continuous heat treatment can be performed by one of two methods: continuous energization heat treatment and continuous running heat treatment.

The continuous energization heat treatment is performed by annealing with Joule heat generated from itself by passing an electric current through a wire passing through two electrode wheels. It includes the steps of rapid heating and quenching, and the wire can be annealed by controlling the wire temperature and annealing time. Cooling is performed by passing the wire continuously in water or a nitrogen gas atmosphere after rapid heating. When one or both of the wire temperature and the annealing time are too low, the necessary flexibility cannot be obtained when mounting on the vehicle, and when too high, the crystal grains become coarse due to over-annealing and the strength and flexibility are lowered. Therefore, in continuous energization heat treatment, if the wire temperature is y (° C.) and the annealing time is x (seconds),
0.03 ≦ x ≦ 0.73, and ^{26x -0.6 + 377 ≦ y ≦ 19x} -0.6 +477
To meet.
The wire temperature y (° C.) represents the temperature immediately before passing through the cooling step, at which the temperature of the wire becomes the highest. y (° C.) is usually in the range of 408 to 633 (° C.).

In the continuous running heat treatment, the wire is continuously passed through an annealing furnace kept at a high temperature and annealed. It includes the steps of rapid heating and rapid cooling, and the wire can be annealed under the control of the annealing furnace temperature and annealing time. Cooling is performed by passing the wire continuously in water or a nitrogen gas atmosphere after rapid heating. If one or both of the annealing furnace temperature and the annealing time are too low, the required flexibility for in-vehicle installation cannot be obtained. If it is too high, the crystal grains become coarse due to over-annealing and the strength and flexibility are reduced. . Therefore, in the continuous running heat treatment, if the annealing furnace temperature is z (° C.) and the annealing time is x (seconds),
1.5 ≦ x ≦ 5, and −50x + 550 ≦ z ≦ −36x + 650
To meet. The annealing furnace temperature z (° C.) is usually in the range of 300 to 596 (° C.).
Further, in addition to the above two methods, the finish annealing may be induction heating in which a wire continuously passes through a magnetic field and is annealed.

  In the aluminum alloy conductor of the present invention, when the above [7] heat treatment (finish annealing) is performed, the tension acting on the conductor during the heat treatment is preferably 1.5 MPa or more and 15 MPa or less. If the tension is too small, it may be difficult to obtain a difference in crystal orientation inside and outside the wire, and crystal grains having the target crystal orientation may not be obtained. If it is too large, the wire cannot withstand the tensile force, and there is a high possibility of causing disconnection. In order to obtain a difference in crystal orientation between the inside and outside of the wire, the tension is preferably high enough not to break, but the higher the effect, the more saturated, so it is preferably 2 to 12 MPa, more preferably 3 to 12 MPa. . The tension applied to the wire can be changed according to the size of each electrode wheel or power wheel to be connected, the wire speed, and the like.

(Alloy composition)
The component constitution of the first embodiment of the present invention is as follows: Fe is 0.01 to 0.4 mass%, Mg is 0.01 mass% or more and less than 0.3 mass%, and Si is 0.01 mass% or more and 0.3 mass%. And 0.01 to 0.5 mass% of Cu, and the balance is Al and inevitable impurities.

  In the present embodiment, the reason why the Fe content is set to 0.01 to 0.4 mass% is mainly to utilize various effects of the Al—Fe-based intermetallic compound. Fe dissolves only 0.05 mass% in aluminum at 655 ° C., and is even less at room temperature. The remainder is crystallized or precipitated as an intermetallic compound such as Al-Fe, Al-Fe-Si, Al-Fe-Si-Mg, Al-Fe-Cu-Si. This crystallized product or precipitate acts as a crystal grain refining material, and improves strength and bending fatigue resistance. On the other hand, the strength also increases due to the solid solution of Fe. If the Fe content is too small, these effects are insufficient. If the Fe content is too large, the intermetallic compound is coarsened, which decreases the strength and bending resistance. Arise. Moreover, it will be in a supersaturated solid solution state and electrical conductivity will fall. The content of Fe is preferably 0.1 to 0.3 mass%, more preferably 0.15 to 0.3 mass%.

  In the present embodiment, the Mg content is set to 0.01 mass% or more and less than 0.3 mass% because Mg is strengthened by solid solution in the aluminum base material, and a part thereof forms a precipitate with Si. This is because the strength, bending fatigue resistance, and heat resistance can be improved. If the Mg content is too low, the effect is insufficient, and if it is too high, the conductivity is lowered. Moreover, when there is much content of Mg, yield strength will become excess, a moldability and twist property will deteriorate, and workability will worsen. The Mg content is preferably 0.05 to 0.3 mass%, more preferably 0.10 to 0.25 mass%.

  In the present embodiment, the Si content is set to 0.01 mass% or more and less than 0.3 mass%, as described above, Si forms a compound with Mg to improve strength, bending fatigue resistance, and heat resistance. This is to show the function of making it happen. If the Si content is too low, the effect is insufficient, and if it is too high, the conductivity decreases. Moreover, when there is much Si content, precipitation of Si single-piece | unit will arise and it will become easy to cause a disconnection. The Si content is preferably 0.02 to 0.25 mass%, more preferably 0.04 to 0.20 mass%.

  In the present embodiment, the reason why the Cu content is 0.01 to 0.5 mass% is to strengthen and dissolve Cu in the aluminum base material. It also contributes to the improvement of creep resistance, bending fatigue resistance and heat resistance. If the Cu content is too low, the effect is insufficient, and if it is too high, the corrosion resistance and the conductivity are lowered. The Cu content is preferably 0.10 to 0.45 mass%, more preferably 0.20 to 0.40 mass%.

The component constitution of the second embodiment of the present invention contains 0.4 to 1.5 mass% of Fe and consists of the balance Al and inevitable impurities.

  In the second embodiment, the Fe content is set to 0.4 to 1.5 mass% in order to use various effects of the intermetallic compound as described in the first embodiment. If the Fe content is too small, the second embodiment does not contain Cu or Mg, so the tensile strength is low. If the amount is too large, the intermetallic compound becomes coarse, and conversely, the strength and bending resistance are lowered. In some cases, the intermetallic compound is the starting point, and disconnection occurs. Moreover, it will be in a supersaturated solid solution state and electrical conductivity will fall. The content of Fe is preferably 0.6 to 1.3 mass%, more preferably 0.8 to 1.1 mass%.

The component constitution of the third embodiment of the present invention contains 0.4 to 1.5 mass% of Fe, 0.01 to 0.3 mass% of Mg, and 0.01 to 0.3 mass% of Si. And the balance Al and inevitable impurities.

In the third embodiment, the content of Fe is larger than that of the alloy composition of the first embodiment described above, and Cu is not contained. The reason why the Fe content is set to 0.4 to 1.5 mass% is mainly to use various effects of the Al—Fe-based intermetallic compound. The effect is as described in the first embodiment. If the Fe content is too small, the third embodiment does not contain Cu, so the tensile strength is low. If the amount is too large, the intermetallic compound becomes coarse, and conversely, the strength and bending resistance are lowered. In some cases, the intermetallic compound is the starting point, and disconnection occurs. Moreover, it will be in a supersaturated solid solution state and electrical conductivity will fall. The content of Fe is preferably 0.6 to 1.3 mass%, more preferably 0.8 to 1.1 mass%.
Other alloy compositions and their actions are the same as in the first embodiment described above.

The component constitution of the fourth embodiment of the present invention is as follows: Fe is 0.01 to 1.5 mass%, Mg is 0.3 to 1.0 mass%, Si is 0.3 to 1.0 mass%, Cu Is an aluminum alloy conductor containing 0.01 to 0.5 mass% and the balance Al and inevitable impurities.

  The reason why the Fe content is set to 0.01 to 1.5 mass% in the present embodiment is to use various effects of the intermetallic compound as described in the first embodiment. If the Fe content is too small, the effect is insufficient. If the Fe content is too large, the intermetallic compound is coarsened, and on the contrary, the strength and bending resistance are lowered. In some cases, the intermetallic compound is the starting point, and disconnection occurs. Moreover, it will be in a supersaturated solid solution state and electrical conductivity will fall. The Fe content is preferably 0.15 to 1.1 mass%, more preferably 0.15 to 0.9 mass%.

  The reason why the Mg content is 0.3 to 1.0 mass% is to precipitate a large amount of Mg-Si-based precipitates and to improve the strength while keeping the electrical conductivity appropriately. If the content of Mg is too small, an increase in strength cannot be expected so much, and if it is too large, the conductivity is lowered. Moreover, when there is much content of Mg, yield strength will become excess, a moldability and twist property will deteriorate, and workability will worsen. The Mg content is preferably 0.4 to 0.9 mass%, more preferably 0.5 to 0.8 mass%.

The reason why the Si content is set to 0.3 to 1.0 mass% is to increase the strength of the Mg-Si-based precipitates by depositing a large amount of Mg-Si-based precipitates and maintaining the conductivity appropriately. If the Si content is too small, an increase in strength cannot be expected so much, and if it is too much, the conductivity decreases. Moreover, when there is much Si content, precipitation of Si single-piece | unit will arise and it will become easy to cause a disconnection. The Si content is preferably 0.4 to 0.9 mass%, more preferably 0.5 to 0.8 mass%.
It is.

  The reason why the Cu content is 0.01 to 0.5 mass% is to strengthen and dissolve Cu in the aluminum base material. If the Cu content is too low, the effect is insufficient, and if it is too high, the corrosion resistance and the conductivity are lowered. The Cu content is preferably 0.05 to 0.4 mass%, more preferably 0.15 to 0.35 mass%.

  The present invention will be described in detail based on the following examples. In addition, this invention is not limited to the Example shown below.

Example 1 and Comparative Example 1
Rolling is carried out while continuously casting the molten metal in a water-cooled mold using a Properti type continuous casting and rolling machine so that Fe, Mg, Si, Cu, and Al are in the amounts (mass%) shown in Table 1. The bar was about 10 mmφ. The casting cooling rate at this time is 1 to 20 ° C./second.
Next, the surface was peeled to about 9.5 mmφ, and this was drawn so as to obtain a predetermined degree of processing. Next, this cold-drawn workpiece was subjected to intermediate annealing at a temperature of 300 to 450 ° C. for 0.5 to 4 hours, and further drawn to a predetermined wire diameter. The wire drawing is performed by die drawing, and the cross-sectional reduction rate of one die is 15% to 30% (including 8% and 32% in the comparative example), and the die half angle is 5 ° to 15 ° (in the comparative example) 4 ° and 17 ° included).
Finally, as a final annealing, a continuous energization heat treatment was performed at a temperature of 438 to 610 ° C. for a time of 0.03 to 0.73 seconds, and a continuous running heat treatment was performed at a temperature of 499 to 523 ° C. for a time of 1.5 to 3.0 seconds.
In the case of continuous energization heat treatment, the wire temperature y (° C.) immediately before passing through the water where the temperature of the wire becomes the highest was measured with a fiber type radiation thermometer (manufactured by Japan Sensor). In the case of continuous running heat treatment, the annealing furnace temperature z (° C.) was measured. The tension during finish annealing was 3.5 to 15.0 MPa (including 1.0 MPa and 20.0 MPa in the comparative example). The tension was measured using a load cell (manufactured by Kyowa Denki).

  Each characteristic was measured with the method described below about the produced each Example and the wire of a comparative example. The results are shown in Table 2.

(B) Area ratio of crystal grains having respective crystal orientations EBSD method was used for analysis of crystal orientation in the present invention. In a cross section perpendicular to the drawing direction of the wire, the crystal orientation was observed mainly for a sample area having a diameter of about 310 μm. The measurement area is set based on the range shown in FIG. 1 (the inside of the circle of radius (3/10) R or the outside of the circle of radius (7/10) R), and the scanning step is the size of the average crystal grain of the sample. Of about 1/5 to 1/10. The area ratio of the crystal grains having each crystal orientation is the area of the crystal grains having each crystal orientation existing in the measurement area of FIG. 1 with respect to the crystal plane located parallel to the cross section perpendicular to the drawing direction. It is given as divided by the total measured area in FIG.
(C) Tensile strength (TS) and tensile elongation at break (flexibility)
Three each were tested according to JIS Z 2241 and the average value was determined. The lower limit of the tensile strength is preferably 80 MPa or more, more preferably 100 MPa or more. The upper limit of the tensile strength is preferably less than 240 MPa, and more preferably less than 220 MPa. As an index for flexibility, the tensile elongation at break is preferably 10% or more. More preferably, it is 15% or more.
(D) Conductivity (EC)
Three specific resistances were measured using a four-terminal method in a constant temperature bath holding a 300 mm long test piece at 20 ° C. (± 0.5 ° C.), and the average conductivity was calculated. The distance between the terminals was 200 mm. The electrical conductivity is not particularly limited, but is preferably higher because it allows electricity to flow.
(E) Number of repeated fractures (bending fatigue resistance)
As a standard for bending fatigue resistance, the strain amplitude at room temperature was set to ± 0.17%. Bending fatigue resistance varies with strain amplitude. When the strain amplitude is large, the fatigue life is shortened, and when the strain amplitude is small, the fatigue life is lengthened. Since the strain amplitude can be determined by the wire diameter of the wire 1 and the bending radii of the bending jigs 2 and 3 shown in FIG. 3, the wire diameter of the wire 1 and the bending radii of the bending jigs 2 and 3 are arbitrarily set and bent. It is possible to conduct a fatigue test.
The number of repeated ruptures by repeatedly bending using a jig that gives a bending strain of 0.17% using a double-bending fatigue tester manufactured by Fujii Seiki Co., Ltd. (currently Fujii Co., Ltd.) Was measured. The number of repeated ruptures was measured four by four and the average value was determined. As shown in the explanatory view of FIG. 3, the wire 1 was inserted with a gap of 1 mm between the bending jigs 2 and 3, and repeatedly moved in such a manner as to be along the jigs 2 and 3. One end of the wire was fixed to a holding jig 5 so that it could be bent repeatedly, and a weight 4 of about 10 g was hung from the other end. Since the holding jig 5 moves during the test, the wire 1 fixed to the holding jig 5 also moves and can be bent repeatedly. The repetition is performed under the condition of 100 times per minute, and when the wire specimen 1 breaks, the weight 4 falls and stops counting. The number of repeated breaks is preferably 100,000 times or more, more preferably 120,000 times or more, and still more preferably 140,000 times or more.

Comparative Example 1-No. Examples 1 to 6 are examples in which the aluminum alloy conductor defined by the present invention was not obtained depending on the production conditions of the aluminum alloy. Comparative Example 1-No. In 1, 3, and 5, the repeated fracture characteristics were poor. Comparative Example 1-No. 2 and 4 were disconnected during the wire drawing process. Comparative Example 1-No. No. 6 was broken during finish annealing.
In contrast, Example 1-No. In Nos. 1 to 13, an aluminum alloy conductor excellent in tensile strength, electrical conductivity, tensile elongation at break (flexibility), and repeated fracture characteristics (flexural fatigue resistance) was obtained.

1 Test piece (wire)
2, 3 Bending jig 4 Weight 5 Holding jig 21 Die 22 Die half angle 41 Standard triangle of stereo projection

Claims (9)

Fe is 0.01 to 0.4 mass%, Mg is 0.01 mass% or more and less than 0.3 mass%, Si is 0.01 mass% or more and less than 0.3 mass%, and Cu is 0.01 to 0.5 mass%. An aluminum alloy conductor comprising the balance Al and inevitable impurities,
Area of crystal grains having a plane inclined at an angle within the range of a standard triangle of a stereo projection view by 25 ° or more from the (111) plane positioned parallel to the cross section perpendicular to the wire drawing direction of the wire. When the radius of the wire is R, the rate is 50% or more in a circle of radius (3/10) R from the center of the wire, and is located parallel to the cross section perpendicular to the wire drawing direction (111). ) The area ratio of crystal grains having a surface inclined in the range of 0 ° or more and less than 25 ° with respect to the normal direction from the surface is excluded from the entire wire rod within a circle of radius (7/10) R from the center of the wire rod An aluminum alloy conductor characterized by being 50% or more in the above range.   An aluminum alloy conductor containing 0.4 to 1.5 mass% of Fe, and the balance being Al and inevitable impurities,
  Area of crystal grains having a plane inclined at an angle within the range of a standard triangle of a stereo projection view by 25 ° or more from the (111) plane positioned parallel to the cross section perpendicular to the wire drawing direction of the wire. When the radius of the wire is R, the rate is 50% or more in a circle of radius (3/10) R from the center of the wire, and is located parallel to the cross section perpendicular to the wire drawing direction (111). ) The area ratio of crystal grains having a surface inclined in the range of 0 ° or more and less than 25 ° with respect to the normal direction from the surface is excluded from the entire wire rod within a circle of radius (7/10) R from the center of the wire rod An aluminum alloy conductor characterized by being 50% or more in the above range.   An aluminum alloy conductor containing 0.4 to 1.5 mass% Fe, 0.01 to 0.3 mass% Mg, 0.01 to 0.3 mass% Si, and the balance Al and inevitable impurities. There,
  Area of crystal grains having a plane inclined at an angle within the range of a standard triangle of a stereo projection view by 25 ° or more from the (111) plane positioned parallel to the cross section perpendicular to the wire drawing direction of the wire. When the radius of the wire is R, the rate is 50% or more in a circle of radius (3/10) R from the center of the wire, and is located parallel to the cross section perpendicular to the wire drawing direction (111). ) The area ratio of crystal grains having a surface inclined in the range of 0 ° or more and less than 25 ° with respect to the normal direction from the surface is excluded from the entire wire rod within a circle of radius (7/10) R from the center of the wire rod An aluminum alloy conductor characterized by being 50% or more in the above range.   Fe containing 0.01 to 1.5 mass%, Mg 0.3 to 1.0 mass%, Si 0.3 to 1.0 mass%, and Cu 0.01 to 0.5 mass% An aluminum alloy conductor composed of the balance Al and inevitable impurities,
  Area of crystal grains having a plane inclined at an angle within the range of a standard triangle of a stereo projection view by 25 ° or more from the (111) plane positioned parallel to the cross section perpendicular to the wire drawing direction of the wire. When the radius of the wire is R, the rate is 50% or more in a circle of radius (3/10) R from the center of the wire, and is located parallel to the cross section perpendicular to the wire drawing direction (111). ) The area ratio of crystal grains having a surface inclined in the range of 0 ° or more and less than 25 ° with respect to the normal direction from the surface is excluded from the entire wire rod within a circle of radius (7/10) R from the center of the wire rod An aluminum alloy conductor characterized by being 50% or more in the above range. The area ratio of crystal grains having a plane inclined in a range of 0 ° or more and 20 ° or less with respect to the normal direction from the (100) plane positioned parallel to the cross section perpendicular to the wire drawing direction is the radius of the wire. the When R, aluminum alloy conductor according to any one of claims 1-4, characterized in that the center of the wire rod is radius (3/10) 50% or more within a circle of R. The area ratio of crystal grains having a plane inclined in the range of 0 ° or more and less than 10 ° with respect to the normal direction from the (111) plane positioned parallel to the cross section perpendicular to the wire drawing direction is the radius of the wire. the When R, from the center of the wire than the entire wire radius (7/10) according to any one of claims 1-5, characterized in that the range except within a circle of R is 50% or more Aluminum alloy conductor. The area ratio of crystal grains having a plane inclined in a range of 10 ° or more and less than 25 ° with respect to the normal direction from the (111) plane positioned parallel to the cross section perpendicular to the wire drawing direction is the radius of the wire. the When R, from the center of the wire than the entire wire radius (7/10) according to any one of claims 1-5, characterized in that the range except within a circle of R is 50% or more Aluminum alloy conductor. The aluminum alloy conductor according to any one of claims 1 to 7 , wherein the aluminum alloy conductor is used as a battery cable, a harness, or a conductor for a motor in a moving body. The aluminum alloy conductor according to claim 8 , wherein the moving body is an automobile, a train, or an aircraft.

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