JPH08120368A - High-tensile conductive copper alloy excellent in elongation property and bendability and its production - Google Patents

Abstract

PURPOSE: To impart excellent bendability, elongation properties and strength to an alloy without executing complicated heat treatment by specifying the compsn. of an Mg-Sn-In-Co copper alloy. CONSTITUTION: This alloy has a compsn. contg., by weight, 0.05 to 0.25% Mg, 0.1 to 0.6% Sn, 0.02 to 0.08% P, 0.02 to 0.2% In, 0.05 to 0.1% Co, and the balance fundamental Cu, and in which the containing ratio of Mn to Sn is regulated to Mn; Sn=(1); (>=1.0). The working of the alloy to a wire rod is executed in such a manner that a bar stock first subjected to melting and continuous casting is rolled and wire-drawn and is subjected to continuous annealing in the temp. range of 500 to 600 deg.C to form into an element wire. Next, it is wire- drawn at 85 to 95% working ratio and is finally subjected to continuous annealing preferably in the temp. range of 350 to 450 deg.C as final heat treatment. Thus, a conductive wire having >=50Kg/mm<2> tensile strength can be formed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a copper alloy, and in particular,
For example, the present invention relates to a conductive high-strength copper alloy excellent in flexibility, elongation property, and tensile strength suitable for use as a conductor of an electric wire for automobiles.

[0002]

2. Description of the Related Art Conventionally, annealed copper wire has been mainly used as a conductor of an automobile electric wire for automobiles, but on-vehicle devices such as various measuring instruments have been computerized, and the number of electric and electronic wiring circuits in the automobile has been increased. Has increased remarkably, the space occupied inside the vehicle has increased, and the total weight of the vehicle due to the electric wires for the vehicle has increased. However, it is desirable that the body of an automobile be lightweight from the viewpoint of improving fuel efficiency. From the viewpoint of reducing the weight of the automobile, even if the number of wiring circuits in the automobile increases, the space occupied by the automobile is small. There is an increasing demand for a reduction in the total weight of electric wires for automobiles. Therefore, in order to reduce the weight of the electric wire for automobiles, a hard copper wire that can secure the mechanical strength even if the outer diameter of the conductor is made small has been studied. Even if the terminals are crimp-bonded using a copper wire, the joint may be damaged if a mechanical load is applied to the joint due to an external force of a vibration shock generated while the vehicle is running. When the terminals are crimp-bonded with each other by using the hard copper wire, the terminal crimping point becomes a mechanical weak point, which easily causes disconnection due to external impact, resulting in poor reliability. Also, reducing the weight of automobile wires can be achieved by reducing the conductor diameter, but in the case of conventional annealed copper wire, reducing the conductor outer diameter decreases the mechanical strength. Will end up. Therefore, in recent years, as a copper alloy that can secure mechanical strength even if the outer diameter of the conductor is reduced and has relatively good repeated bending strength and conductivity, Ni-
A Si-In-Sn copper alloy (Japanese Patent Publication No. 5-27699) has been developed. In this Ni-Si-In-Sn copper alloy, Ni and Si, which are solid-solved in the Cu matrix, are finely precipitated by an age hardening treatment to improve the tensile strength, elongation and conductivity. Further, In and Sn are solid-dissolved in the Cu matrix to further improve the tensile strength.

[0003]

SUMMARY OF THE INVENTION Such a conventional Ni
In the -Si-In-Sn copper alloy, a large amount of expensive Ni is used (usually 2 to 3 wt%), and there is a problem that the cost of the material as the electric wire conductor becomes high. . The high cost of the conductor material affects the price of the electric wire. This increase in the price of electric wires may result in an increase in automobile prices in the automobile sector, where the number of vehicles used is particularly high. This is a big problem in the case of automobile electric wires used in automobiles, which have a relatively short life of a year. In the automobile sector where price competition is fierce, it is required to reduce the vehicle price without lowering the function of the automobile. For that purpose, it is necessary to reduce the cost of all parts of the automobile without deteriorating the performance of each part, and even for the case of electric wires for automobiles, the number of which is being used is increasing especially due to the computerization of engine control. is not. For this reason, the fact that the cost of the material for the wire conductor is high is a major factor in the wire as a whole. In addition, the conventional Ni-Si-In-Sn copper alloy is an age-hardening type copper alloy that undergoes solution treatment and age-hardening treatment.
Equipment for age hardening treatment is required. In the case of this age hardening type copper alloy, good properties as a copper alloy cannot be obtained unless the temperature of the heat treatment is accurately controlled during the solution treatment and the age hardening treatment. However, it is difficult to accurately control the temperature of the heat treatment when performing the solution treatment and the age hardening treatment. Therefore, the Ni-Si-In-Sn copper alloy, which is a conventional age hardening type copper alloy, has a problem that the characteristics are likely to vary. Further, the conventional Ni-Si-In-Sn copper alloy is manufactured by performing solution treatment and age hardening treatment using equipment for solution treatment and age hardening treatment in addition to ordinary electric wire manufacturing equipment. Since it is an age hardening type copper alloy, it has a problem that the processing cost is increased and the product cost is significantly increased.

The object of the present invention is to eliminate the need for complicated heat treatment steps and to prevent the deterioration of the electrical conductivity, and the flexibility, elongation characteristics,
Another object of the present invention is to make it possible to inexpensively manufacture a high-strength copper alloy for electrical conduction, which has improved tensile strength, high strength against mechanical shock, and reduced disconnection due to bending in the crimp terminal.

[0005]

According to the first aspect of the present invention,
Mg is 0.05 to 0.25 wt% and Sn is 0.1 to 0.
6 wt%, P 0.02 to 0.08 wt%, In 0.
02-0.2 wt%, Co of 0.05-0.1 wt%, the balance basically consisting of copper, and the content ratio of Mg and Sn is Mg: Sn = (1) :( 1.0 Above).

According to the second aspect of the invention, Mg is added in an amount of 0.05 to 0.05.
0.25wt%, Sn 0.1-0.6wt%, P 0.02-0.08wt%, In 0.02-0.2w
The content ratio of Mg and Sn is Mg: Sn = (1) :( 1.0 or more). A casting rod produced by continuous casting of a copper alloy is rolled and drawn, then continuously annealed at 500 to 600 ° C., then drawn at a working rate of 85 to 95%, and finally heat treated at 350 to
It is intended to be manufactured by continuous annealing at 450 ° C.

[0007]

According to the first aspect of the present invention, Mg is dissolved in the Cu mother phase to form a solid solution, the tensile strength is improved, and the optimum addition amount of Mg is limited, so that deterioration of castability due to Mg is minimized. By stopping and adding Sn, the bending property is significantly improved, the tensile strength and the elongation after annealing are further improved, and the deterioration of the castability due to the addition of Mg is improved. By adding P, the heat resistance was improved and the castability was further improved. further,
By adding In, the tensile strength is further improved, and by adding Co, the elongation and flexibility are further improved.

It has been conventionally known that when Mg is added to Cu, cast holes and the like are likely to occur during casting and the castability is deteriorated. In particular, during continuous casting, casting cracks are likely to occur, and even when minute casting cracks are rolled or drawn, this minute casting fracture portion becomes a defective portion of the copper alloy after rolling or drawing, and from this defective portion There are a lot of things that happen when you disconnect. For this reason, in the case of Mg copper alloy, the skin is chamfered and then wire drawing is performed, but wire breakage may occur frequently. On the other hand, Mg
Although the addition of is less in the decrease in conductivity, the effect of improving the tensile strength is very large. In the invention according to claim 1, M
The reason why the content of g is 0.05 to 0.25 wt% is that M
When the content of g is less than 0.05 wt%, the effect of improving the tensile strength is small, and even when the content of Mg exceeds 0.25 wt%, the effect of improving the tensile strength is saturated and the conductivity is reduced. This is because the castability deteriorates rapidly and the castability deteriorates rapidly.

Further, addition of Sn improves not only the castability deteriorated by the addition of Mg but also the flexibility. Further, addition of Sn has an effect of improving the tensile strength and also an effect of improving the elongation after annealing. In the invention according to claim 1, the Sn content is set to 0.
1 to 0.6 wt% is because the Sn content is 0.1 w
If it is less than t%, the effect of improving the flexibility and castability is small, and even if the Sn content exceeds 0.6 wt%, the effect of improving the tensile strength and castability is saturated, and the elongation after annealing increases. This is because the flexibility is deteriorated and the conductivity is significantly reduced.

Further, the addition of P has a very large effect of improving the castability by a synergistic effect with Sn, and greatly improves the deterioration of the castability due to the addition of Mg. Although the heat resistance is greatly improved by the addition of P, the addition amount is limited because the conductivity is largely lowered. In the invention according to claim 1, the content of P is set to 0.02 to 0.08 wt%. When the content of P is less than 0.02 wt%, the effect of improving heat resistance is small, and the content of Mg is This is because the castability reduced by the addition cannot be improved, and if the P content exceeds 0.08 wt%, the heat resistance and the castability are improved, but the conductivity is significantly reduced and it is not practical.

Furthermore, the addition of In greatly improves the tensile strength. In the invention of claim 1, the content of In is set to 0.02 to 0.2 wt% because the effect of improving the tensile strength is small when the content of In is less than 0.02 wt%, This is because if the content exceeds 0.2 wt%, the effect of improving the tensile strength is saturated and the conductivity is reduced. In addition, adding a large amount of expensive In increases the cost and is not practical.

Further, the addition of Co improves elongation characteristics and flexibility. In the invention according to claim 1, the content of Co is set to 0.05 to 0.1 wt% because when the Co content is less than 0.05 wt%, the effect of improving the elongation property and the flexibility is small. This is because when the Co content exceeds 0.1 wt%, the effect of improving the elongation characteristics and the flexibility is saturated, and the conductivity decreases.

The addition ratio of Mg and Sn has a great influence on the castability. That is, when the addition amount of Mg is 1, S
The added amount of n must be 1.0 or more. Mg
If the addition ratio of Mg and Sn is Mg> Sn, the castability cannot be improved.

According to the second aspect of the present invention, Mg produced by continuous casting is 0.05 to 0.25 wt% and Sn is less than 0.
1-0.6 wt%, P 0.02-0.08 wt%, I
n is 0.02 to 0.2 wt% and Co is 0.05 to 0.1
wt%, the balance is basically copper, and the content ratio of Mg and Sn is Mg: Sn = (1) :( 1.0 or more). 500-600
Complicated heat treatment process (solution treatment, age hardening treatment) by continuous annealing at ℃, wire drawing at a working rate of 85 to 95%, and final annealing at 350 to 450 ℃ It is possible to obtain an inexpensive copper alloy that is a solid solution strengthened copper alloy that does not require, and is particularly excellent in bending properties and wire drawing properties, and also in tensile strength and elongation.

[0015]

EXAMPLES Hereinafter, specific examples of the high-strength copper alloy for electroconductivity according to the invention of claim 1 of the present invention, which are excellent in the elongation property and the bending property, will be described in comparison with comparative examples and conventional examples. As an embodiment of the invention according to claim 1 of the present application, in a crucible furnace made of graphite kept in an inert gas atmosphere, Mg, Sn, In are pure metals after melting electrolytic copper metal under the graphite grain coating. In this form, P and Co are added in the form of a master alloy to obtain a uniform molten metal. This was continuously cast to produce a 20 mmφ cast rod having the composition of each of the examples (No. 1 to No. 11) shown in Table 1. After cold rolling these, 3.2mmφ by wire drawing machine
Was drawn and continuously annealed at 550 ° C. This was further drawn to a diameter of 1.0 mm by a wire drawing machine, and then continuously annealed at 420 ° C. using an electric furnace in an inert gas atmosphere. afterwards,
The electrical conductivity, tensile strength, elongation and flexibility were measured.

Conventional Example 1 is a graphite crucible furnace kept in an inert gas atmosphere, in which electrolytic copper ingots are melted under a graphite grain coating, and then Ni, Sn, In are in the form of pure metal.
Si is added in the form of a master alloy to obtain a uniform molten metal. This was continuously cast to produce a 20 mmφ cast rod having the composition shown in Table 1. After cold-rolling this, 3.
After wire drawing to 2 mmφ, it was heated and held at 900 ° C. for 1 hour in an inert gas atmosphere furnace, and then cooled with water to be subjected to solution treatment. After that, the wire was drawn to 1.0 mmφ, and further, an age hardening treatment was performed at 470 ° C. for 6 hours in an inert gas atmosphere furnace. afterwards,
The electrical conductivity, tensile strength, elongation and flexibility were measured. Hard copper is a normal oxygen-free copper wire. Further, for the annealed copper, an ordinary oxygen-free copper wire was annealed at 300 ° C. for 2 hours in an inert gas atmosphere furnace, and then the electrical conductivity, tensile strength, elongation and flexibility were measured. Comparative examples (No. 1 to No. 10) are shown in Table 2, and each comparative example is manufactured by the same manufacturing method as that of the example. As for the annealing temperature in each continuous annealing machine shown in Tables 1 and 2, assuming that the thermal efficiency is 90%, the annealing voltage (V), the annealing speed (m / min), the conductor resistance (Ω) of each copper alloy wire. ). Further, as shown in FIG. 1, the bending test for each of the copper alloys shown in Tables 1 and 2 was performed by sandwiching the test material 2 in the jig 1.
With the other end being subjected to a tensile load W of 2 kg, the left and right 90 ° bends are made as shown in FIG. 1 (A) → (B) → (C) → (D).
The test piece was repeatedly bent until it broke, and the repetitive bending strength expressed by the number of times of bending until rupture was defined as the flexibility. The alloys No. 1 to No. 10 of the comparative example have compositions of Mg and S.
Although it is composed of the same composition components as n, P, In and alloys No. 1 to No. 11 of the present invention, the content of each composition of the comparative example alloy is different from the content of each composition of the present invention.

[0017]

[Table 1]

[Table 2] The examples (No. 1 to No. 11) in Table 1 are Ni of the conventional example 1.
Although it is slightly inferior in tensile strength to the -Si-In-Sn copper alloy, it has good characteristics in electrical conductivity, elongation and flexibility (repetitive flexural strength). In addition, the embodiment (No1
It can be seen that Nos. 11 to 11) have inferior electrical conductivity as compared with hard copper, but have significantly improved tensile strength, elongation and flexibility.

Further, in the examples (No1 to No11),
It can be seen that as compared with annealed copper, which has excellent flexibility, the flexibility has characteristics equal to or greater than those of annealed copper. Thus, Table 1
It can be understood that the examples (No. 1 to No. 11) of (1) to (11) have comprehensively superior characteristics as compared with the conventional examples.

Comparative examples (No. 1 to No. 10) in Table 2 are as follows. In Comparative Example 1, the added amount of Mg is not less than the upper limit and the tensile strength is good, but the conductivity, the elongation rate, and the flexibility are lowered. Further, the ratio of Mg: Sn is 1 :.
Since it is 1.0 or less, the wire drawing workability in the wire drawing machine is deteriorated. In Comparative Example 2, the addition amount of Mg is less than or equal to the lower limit, so that the tensile strength and the elongation rate are significantly inferior. In Comparative Example 3, the added amount of Sn is not less than the upper limit and the tensile strength is good, but the conductivity,
The elongation and flexibility are extremely poor. In Comparative Example 4, since the amount of Sn added is not more than the lower limit, the electrical conductivity is good, but the tensile strength, the elongation rate, and the flexibility are significantly poor. Further, since the ratio of Mg: Sn is 1: 1.0 or less, the wire drawing workability of the wire drawing machine is deteriorated. In Comparative Example 5, since the amount of P added is not less than the upper limit, the conductivity is significantly inferior. In Comparative Example 6, since the amount of P added is not more than the lower limit, the conductivity is good, but the wire drawing workability in the wire drawing machine deteriorates. In Comparative Example 7, since the amount of In added is not less than the upper limit, the tensile strength is good, but the conductivity is significantly poor. In Comparative Example 8, since the amount of In added is equal to or less than the lower limit,
Poor tensile strength. In Comparative Example 9, since the amount of Co added is not less than the upper limit, the conductivity is significantly inferior. In Comparative Example 10, since the amount of Co added is not more than the lower limit, the elongation rate and the flexibility are inferior.

Therefore, according to the embodiment of the high-strength copper alloy for electric conduction which is excellent in the elongation property and the bending property according to the present invention, it has the properties suitable for the conductor of the electric wire for automobiles, the outer diameter of the conductor is small and the weight is light. It is possible to secure the mechanical strength corresponding to the increase in the number of wires and reduce the disconnection due to the pulling and bending in the crimp terminal portion. Further, according to this embodiment, the manufacturing cost can be reduced.

Next, an example of a method for producing a high-strength copper alloy for electrical conduction having excellent elongation and bending characteristics according to the present invention will be described in comparison with a comparative example. Claim 2
The manufacturing method of the high-strength copper alloy for electric conduction excellent in the elongation property and the bending property according to the described invention is M manufactured by continuous casting.
g is 0.05 to 0.25 wt%, Sn is 0.1 to 0.6
wt%, P 0.02 to 0.08 wt%, In 0.0
2 to 0.2 wt%, Co of 0.05 to 0.1 wt% and the balance basically made of copper, and the content ratio of Mg and Sn is Mg: Sn = (1) :( 1.0 Above) is a copper alloy casting rod, which is 500 to 600 after rolling and wire drawing.
It is manufactured by continuously annealing at 0 ° C, drawing at a working rate of 85 to 95%, and finally annealing at 350 to 450 ° C for final heat treatment.

The continuous annealing of the cast rod produced by continuous casting after rolling and wire drawing restores the work structure in rolling and wire drawing, and the elongation and bendability of the final heat treatment without lowering the tensile strength. Is to improve. And, the annealing temperature of the continuous annealing is set to 500 to 600 ° C., because the working structure in rolling and wire drawing cannot be sufficiently recovered at a temperature where the annealing temperature is lower than 500 ° C. If the annealing temperature is not improved and the annealing temperature exceeds 600 ° C., the discoloration during the annealing treatment is remarkable, and it becomes difficult to adjust the winding tension as a wire rod. Further, the reason why wire drawing is performed after annealing at 500 to 600 ° C. is to improve elongation and flexibility without significantly reducing tensile strength in the final heat treatment. And, the processing rate of this wire drawing is set to 85 to 95% because when the processing rate is less than 85%, sufficient tensile strength cannot be secured after the final heat treatment, and when the processing rate exceeds 95%, the final heat treatment is performed. This is because the elongation and flexibility are not sufficiently improved later. Further, the reason why the continuous annealing is performed and the final heat treatment is performed is to improve elongation and flexibility.
And the reason why the annealing temperature of this continuous annealing is 350 to 450 ° C. is that the elongation does not sufficiently improve at a temperature below 350 ° C. and the tensile strength decreases at an annealing temperature above 450 ° C. is there.

Table 3 shows examples and comparative examples of the conductive high-strength copper alloy manufactured by the manufacturing method of the conductive high-strength copper alloy excellent in the elongation property and the bending property. Table 3
Example (No12) and Comparative Examples (No11 to No)
In 15), the composition components are the same but the manufacturing method is changed.

[0024]

[Table 3] Example 12 has the same composition as Example 11 in Table 1 and was manufactured by the same manufacturing method. That is, Example 12 is a graphite crucible furnace kept in an inert gas atmosphere, in which electrolytic copper ingot is melted under the graphite grain coating, and Mg, Sn, In are added in the form of pure metal, and P , C
O was added in the form of a mother alloy to obtain a uniform molten metal, which was continuously cast to form a 20 mmφ casting rod, which was further cold-rolled and then drawn to 3.2 mmφ by a wire drawing machine at 550 ° C. After continuous annealing, draw wire to 1.0mmφ by wire drawing machine,
It was manufactured by continuous annealing at 420 ° C. using an electric furnace in an inert gas atmosphere. As a result of conducting various characteristic tests on the wire material of the high-strength copper alloy for electroconductivity, the electric conductivity was 63.8.
% IACS, tensile strength 55.2 kg / mm ² , elongation rate 9.0
%, The flexibility is 48 times.

In Comparative Example 11, the intermediate annealing temperature is 350 ° C., which is lower than the lower limit value of the annealing temperature range (500 to 600 ° C.), and the work structure in rolling and wire drawing cannot be sufficiently restored by the intermediate annealing. However, the elongation ratio was 7.2% and could not be improved as in Example 12 without lowering the tensile strength in the final annealing. In Comparative Example 12, the wire drawing work ratio from the intermediate annealing to the final annealing is 75%, which is less than or equal to the lower limit of the work ratio range (85 to 95%), and the tensile strength is 4 or less.
After the final heat treatment of 8.2 kg / mm ² , improvement in tensile strength due to wire drawing cannot be sufficiently obtained. In Comparative Example 13, the wire drawing work ratio from the intermediate annealing to the final annealing is 99%, which is equal to or higher than the upper limit value of the work ratio range, and the tensile strength in the final annealing is 57.
It does not decrease to 4kg / mm ² , but the elongation is 7.0.
%, The flexibility cannot be improved to 40 times.

In Comparative Example 14, the final annealing temperature was 320 ° C., which was lower than the lower limit of the annealing temperature range (350 to 450 ° C.), and the tensile strength was good at 56.4 kg / mm ² , but the annealing effect was good. Not obtained, the elongation is 4.8%, and the flexibility is 36 times, which is not improved. In Comparative Example 15, the final annealing temperature is 500 ° C., which is equal to or higher than the upper limit of the annealing temperature range, and the electrical conductivity is 67.4%.
The IACS and elongation are 9.4% and the flexibility is 49 times, which is good, but the tensile strength is significantly reduced to 44.8 kg / mm ² .

As described above, according to this embodiment, complicated heat treatment steps such as solution treatment and aging treatment can be omitted, and both the intermediate annealing for solution treatment and the final annealing for aging treatment can be performed in the wire manufacturing process. It can be carried out by two heat treatments using a commonly used continuous annealing machine,
It has a tensile strength higher than that of hard copper, and its conductivity decreases slightly,
It has better flexibility than annealed copper and has the conventional Ni-Si-I
The tensile strength is lower than that of the n-Sn copper alloy, but the elongation, conductivity, and flexibility are excellent, and the additive element is Ni-Si-I.
It is cheaper than the n-Sn copper alloy and the manufacturing process can be simplified.

[0028]

According to the invention of claim 1, 0.05 to 0.25 wt% of Mg and 0.1 to 0.6 wt% of Sn are used.
%, P 0.02-0.08 wt%, In 0.02-
0.2 wt%, containing 0.05-0.1 wt% Co,
Since the balance is basically made of copper and the content ratio of Mg and Sn is (1) :( 1.0 or more), a complicated heat treatment step is not required and the conductivity is not lowered. It is possible to inexpensively manufacture a high-strength copper alloy for electric conduction, which has improved flexibility, elongation property, and tensile strength, maintains high strength against mechanical impact, and has reduced disconnection due to bending in the crimp terminal portion.

According to the second aspect of the present invention, the Mg content of 0.
05-0.25wt%, Sn 0.1-0.6wt%,
P is 0.02 to 0.08 wt%, In is 0.02 to 0.
2 wt%, 0.05 to 0.1 wt% Co, and the balance basically composed of copper, and the content ratio of Mg and Sn is
(1): A copper alloy made to be (1.0 or more) is continuously cast, and a cast rod is rolled and drawn at 500 to 600 ° C.
By continuous annealing, then wire drawing at a working rate of 85-95%, and continuous annealing at the final heat treatment at 350-450 ° C to produce a complicated heat treatment step (solution treatment, age hardening treatment). It is an unnecessary solid solution strengthened copper alloy, and it is possible to obtain an inexpensive copper alloy having excellent bending properties, wire drawing properties, tensile strength and elongation.

[Brief description of drawings]

FIG. 1 is a diagram showing a bending test method of an example of the present invention, a comparative example, and a conventional example.

[Explanation of symbols]

 1 …………………………………… Jig 2 …………………………………… Test material

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[Procedure amendment]

[Submission date] February 13, 1995

[Procedure Amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0017

[Correction method] Change

[Correction content]

[0017]

[Table 1]

[Table 2] The examples (No. 1 to No. 11) in Table 1 are Ni of the conventional example 1.
Although it is slightly inferior in tensile strength to the -Si-In-Sn copper alloy, it has good characteristics in electrical conductivity, elongation and flexibility (repetitive flexural strength). In addition, the embodiment (No1
It can be seen that Nos. 11 to 11) have inferior electrical conductivity as compared with hard copper, but have significantly improved tensile strength, elongation and flexibility.

Claims (2)

[Claims] 1. Mg-0.05-0.25 wt%, Sn
0.1 to 0.6 wt%, P 0.02 to 0.08 wt
%, In 0.02 to 0.2 wt%, Co 0.05 to
0.1 wt% content, the balance being basically copper, and the content ratio of Mg and Sn is Mg: Sn = (1) :( 1.0 or more), which is excellent in elongation property and bending property. High strength copper alloy for use. 2. Mg-0.05-0.25 wt%, Sn
0.1 to 0.6 wt%, P 0.02 to 0.08 wt
%, In 0.02 to 0.2 wt%, Co 0.05 to
Casting made by continuous casting of a copper alloy containing 0.1 wt% and the balance being basically copper, and the content ratio of Mg and Sn is Mg: Sn = (1) :( 1.0 or more) After rolling and drawing, the bar is continuously annealed at 500 to 600 ° C., then drawn at a working rate of 85 to 95%, and finally heat treated at 350 to
A method for producing a high-strength copper alloy for electrical conduction, which is produced by continuous annealing at 450 ° C. and has excellent elongation and bending characteristics.