JP6131542B2 - Copper alloy wire, copper alloy wire manufacturing method, stranded wire - Google Patents

Description

The present invention relates to a copper alloy wire, a copper alloy wire manufacturing method, and a stranded wire that are excellent in electrical conductivity and repeated bending characteristics and are suitable for wiring cables such as robot arm portions, portable terminals, and PC hinge portions.

The wiring cable used in the above-described robot arm, mobile terminal, PC hinge, etc., is repeatedly subjected to bending, twisting, and the like, and therefore is not easily broken even when repeatedly bending is applied ( Hereinafter, repeated bending characteristics are required. Moreover, since it supplies electricity, high electroconductivity is also requested | required.
Here, normally, in the wiring cable for energization, copper wire made of tough pitch copper having good conductivity is widely used, but its strength is low and repeated bending characteristics are insufficient.

For this reason, for example, a copper alloy wire made of a solid solution strengthened copper alloy such as Sn-containing copper shown in Patent Document 1 and In-containing copper shown in Patent Document 2 is used. In these solid solution strengthened copper alloys described in Patent Documents 1 and 2, since the strength is high, repeated bending characteristics are improved as compared with tough pitch copper. Specifically, in the bending resistance test, which is an evaluation index for repeated bending characteristics, the number of repeated bending until breakage under the same conditions is about 1.3 to 2.5 times that of tough pitch copper.
However, recently, with the miniaturization and thinning of the robot arm, mobile terminal, and PC, the above-described copper alloy wire is required to have further improved repeated bending characteristics.

Further, as a copper alloy wire having improved bending resistance, for example, a copper alloy wire made of a precipitation-strengthened alloy such as a Cu—Fe—P alloy shown in Patent Documents 3 and 4 and a Cu—Cr—Zr alloy shown in Patent Document 5 Has been proposed.
These precipitation-strengthening-type copper alloys can obtain repeated bending characteristics superior to those of a solid-solution-strengthening-type copper alloy by uniformly dispersing precipitates in the copper matrix.

Japanese Patent No. 3348501 Japanese Patent Laid-Open No. 09-056632 JP 61-064835 A1 JP-A-62-214146 JP-A-11-181560

By the way, as for the wiring cable used for the arm part of a robot, the portable terminal, and the hinge part of PC, the extra fine wire with a diameter of 0.08 mm or less is generally used with a single wire.
As described above, in the precipitation-strengthened copper alloy, the conductivity and strength are improved by precipitating and dispersing precipitates by aging heat treatment.
Here, when cold working is carried out after aging heat treatment, precipitates having a small particle size are sheared by dislocations generated during cold working and re-dissolved in the copper matrix, resulting in a decrease in conductivity. It has been pointed out that. In particular, as described above, in the case of an ultrafine wire having a diameter of 0.08 mm or less, the working rate of the cold working after the aging heat treatment is high, the decrease in the conductivity is remarkable, and the desired conductivity is ensured. There was a risk of not being able to.

The present invention has been made in view of the above-described circumstances, and is excellent in conductivity and repeated bending characteristics, and is repeatedly subjected to bending, twisting, etc., such as a robot arm, a mobile terminal, and a PC hinge. An object of the present invention is to provide a copper alloy wire, a method for producing the copper alloy wire , and a stranded wire suitable for a wiring cable used in a part to be used.

In order to solve the above-described problems, the copper alloy wire according to the present invention includes Co; 0.12% by mass to 0.40% by mass, P; 0.040% by mass to 0.16% by mass, Sn; Precipitates observed by observing the cross-sectional structure immediately after aging heat treatment, comprising a precipitation-strengthened copper alloy having a composition including 0.005 mass% to 0.70 mass% with the balance being Cu and inevitable impurities The number of precipitates having an average particle size of 15 nm or more and a particle size of 5 nm or more is 80% or more of the total observed precipitates, and is cold worked after the aging heat treatment. The outer diameter is 0.015 mm or more and 0.2 mm or less, the bending portion R is 5 mm, the load is 20 g, the number of times of bending back by 180 ° and returning to the original position is counted twice, When bending is repeated until it occurs, Bending number until disconnection occurs is characterized in that there is a higher 1154 times.

The copper alloy wire according to the present invention described above is made of a precipitation-strengthened copper alloy containing Co, P and Sn, and the average particle size of the precipitate observed by observation of the cross-sectional structure immediately after the aging heat treatment is 15 nm. Since the number of precipitates having a particle size of 5 nm or more is 80% or more of the total observed precipitates, the number of precipitates having a small particle size made of a compound containing Co and P is small. Therefore, the re-dissolution of precipitates in the subsequent cold working can be suppressed, and the electrical conductivity can be ensured.
That is, a precipitate made of a compound containing Co and P having a particle size of less than 5 nm deposited by aging heat treatment is sheared by dislocation and further subdivided during the cold working after the aging heat treatment, and finally the copper matrix. It will re-dissolve inside. Therefore, in the state after aging heat treatment and before cold working, the number of precipitates having a particle size of less than 5 nm is set to be less than 20% of the total observed precipitates, thereby suppressing re-solution of precipitates. It becomes possible.
In addition, since the average particle diameter of the precipitate made of the compound containing Co and P is 15 nm or more, the precipitate is sufficiently precipitated, the conductivity can be improved, and the strength and repeated bending characteristics can be improved. Can be improved.

The composition of the precipitation strengthening type copper alloy, Co; 0.12 wt% 0.40 wt% or less, P; 0.040 wt% or more 0.16 wt% or less, Sn; 0.005 mass% or more It contains 0.70 mass% or less, and the balance is Cu and inevitable impurities .
In the copper alloy wire having this configuration, precipitates made of a compound containing Co and P are dispersed in the copper matrix, and the strength and conductivity can be improved.
When Co and P are below the lower limit, the number of precipitates is insufficient, and the strength and repeated bending characteristics cannot be sufficiently improved. On the other hand, if Co and P exceed the upper limit values, there are many elements that do not contribute to the improvement of strength, which may cause a decrease in conductivity. For this reason, it is desirable to set Co and P within the above-mentioned range.
Sn is an element having an effect of improving strength by solid solution in a copper matrix. In addition, the effect of promoting the precipitation of precipitates containing Co and P as main components, and the heat resistance and corrosion resistance can be improved. In order to ensure that such effects are achieved, the Sn content needs to be 0.005 mass% or more. In addition, when Sn is added excessively, the electrical conductivity is lowered. Therefore, the Sn content is preferably 0.70% by mass or less.
In addition, it is more preferable to make content of P into the range of 0.097 mass% or more and 0.16 mass% or less.

Moreover, it is preferable that the said precipitation strengthening type copper alloy contains Ni; 0.01 mass% or more and 0.15 mass% or less further.
Since the copper alloy wire having this configuration contains Ni within the above-described range, the coarsening of crystal grains can be suppressed, and the strength and repeated bending characteristics can be further improved.

The precipitation-strengthened copper alloy further contains Zn: 0.002% by mass to 0.5% by mass, Mg: 0.002% by mass to 0.25% by mass, Ag: 0.002% by mass to 0% It is preferable that any one or more of 25% by mass or less and Zr: 0.001% by mass or more and 0.1% by mass or less are included.
In the copper alloy wire having this configuration, one or more of Zn, Mg, Ag, and Zr are contained in the above-mentioned range, so that these elements form a compound with sulfur (S). Thus, it is possible to suppress sulfur (S) from being dissolved in the copper parent phase and to suppress deterioration of mechanical properties such as strength.

The method for producing a copper alloy wire according to the present invention is a method for producing the above-described copper alloy wire, and includes a continuous casting and rolling step for continuously producing a copper rough drawn wire, and a copper produced by the continuous casting and rolling step. A primary cold process for obtaining a copper wire by subjecting the rough wire to a cold work, an aging heat treatment process for performing an aging heat treatment on the copper wire, and a secondary cold work performed after the aging heat treatment process. has a step, and the average particle size of the precipitates observed by sectional microstructure observation immediately after carrying out the aging heat treatment process and more 15 nm, and the number of particle size 5nm or more precipitates are observed It is characterized by being 80% or more of the entire precipitate.

In the manufacturing method of the copper alloy wire according to the present invention described above, an aging heat treatment step and a secondary cold working step performed after the aging heat treatment step, and immediately after the aging heat treatment step is performed. The average particle size of the precipitates observed by cross-sectional structure observation is 15 nm or more, and the number of precipitates having a particle size of 5 nm or more is 80% or more of the total precipitates to be observed. , It is possible to suppress the precipitation of the solid solution again, and it is possible to produce a copper alloy wire excellent in conductivity.
In addition, you may provide the stranded wire processing process which twists together the some copper alloy wire obtained by the secondary cold working process, and makes it a stranded wire.
Moreover, you may implement the last heat processing process for distortion removal with respect to the copper alloy wire obtained by the secondary cold working process. In this final heat treatment step, the heat treatment temperature is preferably 400 ° C. or lower. Furthermore, this final heat treatment step may be performed in the state of a copper alloy wire (single wire), or may be performed in the state of a stranded wire after the above-described stranded wire processing step.

Strands according to the present invention is characterized in that the copper alloy wire mentioned above is a plurality of twisted keyed structure.

According to the present invention, it has excellent conductivity and repeated bending characteristics, and is suitable for a wiring cable used in a portion where bending or twisting is repeatedly applied, such as a robot arm part, a portable terminal and a PC hinge part. A copper alloy wire, a copper alloy wire manufacturing method , and a stranded wire can be provided.

It is a flowchart of the manufacturing method of the copper alloy wire which is embodiment of this invention, and the manufacturing method of a cable conductor. It is a schematic explanatory drawing of the continuous casting rolling equipment used with the manufacturing method of the copper alloy wire which is embodiment of this invention, and the manufacturing method of a cable conductor. It is a schematic explanatory drawing of the bending test method implemented in the Example.

Below, the manufacturing method of the copper alloy wire which concerns on embodiment of this invention is demonstrated with reference to attached drawing.
The copper alloy wire according to the present embodiment is used as a strand of a wiring cable such as an arm portion of a robot.
The wiring cable for the robot includes a cable conductor formed by twisting a plurality of copper alloy wires, and an insulating coating that covers the outer periphery of the cable conductor.

Here, the copper alloy wire according to the present embodiment is Co: 0.12% by mass or more and 0.40% by mass or less, P: 0.040% by mass or more and 0.16% by mass or less, Sn: 0.005% by mass. It is composed of a copper alloy having a composition that includes 0.70% by mass or less and the balance being Cu and inevitable impurities.
In addition, in this copper alloy, Ni; 0.01 mass% or more and 0.15 mass% or less may be included. Further, Zn: 0.002% by mass to 0.5% by mass, Mg: 0.002% by mass to 0.25% by mass, Ag: 0.002% by mass to 0.25% by mass, Zr; Any one or two or more of 0.001% by mass or more and 0.1% by mass or less may be included.
The reason why the content of each element is set within the above range will be described below.

(Co and P)
Co and P are elements that form precipitates dispersed in the copper matrix.
Here, when the Co content is less than 0.12 mass% and the P content is less than 0.04 mass%, the number of precipitates is insufficient, and the strength and repeated bending characteristics are sufficiently improved. You may not be able to. On the other hand, when the Co content exceeds 0.40% by mass and the P content exceeds 0.16% by mass, there are many elements that do not contribute to the improvement of the strength, resulting in a decrease in conductivity. There is a risk of inviting.
For this reason, it is desirable to set the Co content within the range of 0.12 mass% to 0.40 mass% and the P content within the range of 0.040 mass% to 0.16 mass%.

(Sn)
Sn is an element having an action of improving strength by being dissolved in a copper matrix. In addition, it has an effect of promoting precipitation of precipitates containing Co and P as main components and an effect of improving heat resistance and corrosion resistance.
Here, when content of Sn is less than 0.005 mass%, there exists a possibility that the effect mentioned above may not be achieved reliably. On the other hand, when the Sn content exceeds 0.70% by mass, the conductivity may not be ensured.
For this reason, it is desirable to set the content of Sn within the range of 0.005 mass% to 0.70 mass%.

(Ni)
Ni is an element that can replace a part of Co and has an effect of suppressing coarsening of crystal grains.
Here, when the content of Ni is less than 0.01% by mass, the above-described functions and effects may not be reliably achieved. On the other hand, when the Ni content exceeds 0.15% by mass, the conductivity may not be ensured.
For this reason, when it contains Ni, it is preferable to make content of Ni into the range of 0.01 mass% or more and 0.15 mass% or less.

(Zn, Mg, Ag, Zr)
Elements such as Zn, Mg, Ag, and Zr are elements having an effect of generating a compound with sulfur (S) and suppressing the solid solution of sulfur (S) in the copper matrix.
Here, when the content of elements such as Zn, Mg, Ag, and Zr is less than the above lower limit value, the effect of suppressing the solid solution of sulfur (S) in the copper matrix is sufficiently successful. I can't let you. On the other hand, when the content of elements such as Zn, Mg, Ag, and Zr is larger than the above-described upper limit values, the conductivity may not be ensured.
For this reason, when elements, such as Zn, Mg, Ag, and Zr, are contained, it is preferable to be in the above-mentioned range.

And in the copper alloy wire which is this embodiment, the average particle diameter of the precipitate observed by cross-sectional structure | tissue observation immediately after implementing the aging heat treatment process S03 mentioned later is 15 nm or more, and particle diameter is 5 nm or more. The number of precipitates is 80% or more of the total precipitates observed, and after this aging heat treatment step S03, it is assumed that it was manufactured by cold working (secondary cold working step S04). Yes.
Here, the observation of the precipitate was performed as follows. Observation was performed with a transmission electron microscope at magnifications of 150,000 and 750,000 times, the area of the precipitate was calculated, and the equivalent circle diameter was calculated as the particle diameter. The precipitates having a particle diameter of 11 to 100 nm at a magnification of 150,000 times and the precipitates having a particle diameter of 1 to 10 nm at a magnification of 750,000 times were measured. Since observations at a magnification of 750,000 cannot clearly discriminate precipitates less than 1 nm, the total number of precipitates observed is the number of precipitates having a particle size of 1 nm or more. Observation with a transmission electron microscope was performed with a visual field area of about 4 × 10 ⁵ nm ² when the magnification was 150,000 times and with a visual field area of about 2 × 10 ⁴ nm ² when the magnification was 750,000 times.

Next, the manufacturing method of the above-mentioned copper alloy wire and the manufacturing method of the cable conductor will be described. FIG. 1 shows a flow chart of a copper alloy wire manufacturing method and a cable conductor manufacturing method according to an embodiment of the present invention.
First, the copper roughing wire 50 made of the copper alloy is continuously produced by a continuous casting and rolling method (continuous casting and rolling step S01). In the continuous casting and rolling step S01, for example, the continuous casting and rolling equipment shown in FIG. 2 is used.

  The continuous casting and rolling equipment shown in FIG. 2 has a melting furnace A, a holding furnace B, a casting rod C, a belt wheel type continuous casting machine D, a continuous rolling device E, and a coiler F.

  In this embodiment, a shaft furnace having a cylindrical furnace body is used as the melting furnace A. A plurality of burners (not shown) are arranged in a multistage shape in the vertical direction at the lower part of the furnace body. And the electrolytic copper which is a raw material is inserted from the upper part of a furnace main body, is melt | dissolved by the combustion of the said burner, and a copper melt is continuously produced.

  The holding furnace B is for temporarily storing the molten copper produced in the melting furnace A while holding it at a predetermined temperature, and sending a certain amount of the molten copper to the casting iron C.

  The cast iron C is for transferring the molten copper sent from the holding furnace B to the tundish 11 disposed above the belt wheel type continuous casting machine D. The cast iron C is sealed with, for example, an inert gas such as Ar or a reducing gas. The cast iron C is provided with a degassing means (not shown) for stirring the molten copper with an inert gas to remove oxygen and the like in the molten metal.

  The tundish 11 is a storage tank provided for continuously supplying molten copper to the belt wheel type continuous casting machine D. A pouring nozzle 12 is disposed at the end of the tundish 11 in the flow direction of the molten copper, and the molten copper in the tundish 11 passes to the belt wheel continuous casting machine D via the pouring nozzle 12. It is set as the structure supplied.

  Here, in this embodiment, an alloy element addition means (not shown) is provided in the casting iron C and the tundish 11, and the above-mentioned elements (Co, P, Sn, etc.) are added to the molten copper. It is configured.

  The belt wheel type continuous casting machine D includes a cast wheel 13 having a groove formed on the outer peripheral surface thereof, and an endless belt 14 that is circulated so as to contact a part of the outer peripheral surface of the cast wheel 13. . In the belt wheel type continuous casting machine D, molten copper is injected into the space formed between the groove and the endless belt 14 via the pouring nozzle 12, and the molten copper is cooled and solidified. The rod-shaped cast copper material 21 is continuously cast.

A continuous rolling device E is connected to the downstream side of the belt wheel type continuous casting machine D. The continuous rolling apparatus E continuously rolls the cast copper material 21 produced from the belt wheel type continuous casting machine D to produce a copper roughing wire 50 having a predetermined outer diameter.
The copper roughing wire 50 produced from the continuous rolling device E is wound around the coiler F via the cleaning / cooling device 15 and the flaw detector 16.
Here, the outer diameter of the copper roughing wire 50 produced by the above-mentioned continuous casting and rolling equipment is, for example, 8 mm or more and 40 mm or less, and is 8 mm in this embodiment.
In this continuous casting and rolling step S01, the cast copper material 21 is held at a relatively high temperature of, for example, 800 ° C. to 1000 ° C., so that many elements such as Co and P are dissolved in the copper matrix. become.

  Next, as shown in FIG. 1, cold working is performed on the copper roughing wire 50 produced by the continuous casting and rolling step S01 (primary cold working step S02). In the primary cold working step S02, a plurality of steps are performed to obtain a copper wire having an outer diameter of 0.1 mm or more and 8.0 mm or less. In the present embodiment, the copper wire has an outer diameter of 0.9 mm.

Next, an aging heat treatment is performed on the copper wire after the primary cold working step S02 (aging heat treatment step S03). Through this aging heat treatment step S03, a precipitate made of a compound containing Co and P as main components is precipitated.
Here, in the aging heat treatment step S03, the heat treatment temperature is 400 ° C. or more and 600 ° C. or less, and the holding time is 0.5 hours or more and 6.0 hours or less.

Next, cold working is performed on the copper wire after the aging heat treatment step S03 to obtain a copper alloy wire having a predetermined cross-sectional shape (secondary cold working step S04).
In this secondary cold working step S04, a plurality of steps are performed to obtain a copper alloy wire having an outer diameter of 0.015 mm to 0.2 mm. The copper alloy wire of the present embodiment has an outer diameter of 0.08 mm.

  Next, a plurality of copper alloy wires obtained as described above (40 in the present embodiment) are twisted to form a cable conductor (twisted wire processing step S05). In the present embodiment, the twist pitch in the stranded wire processing step S05 is set to 4 mm or more and 24 mm or less.

And the heat treatment for 30 minutes or more and 300 minutes or less is performed by batch type at 100 degreeC or more and 400 degrees C or less for the purpose of distortion removal with respect to the cable conductor obtained by the strand wire processing process S05 (final heat treatment process S06).
In the final heat treatment step S06, various means such as a heat treatment using a tubular furnace that allows the wire to pass therethrough and an electric annealing can be used in addition to the batch-type heat treatment.

According to the copper alloy wire of the present embodiment configured as described above, the average particle size of precipitates observed by cross-sectional structure observation immediately after performing the aging heat treatment step S03 is 15 nm or more, and the grains Since the number of precipitates having a diameter of 5 nm or more is 80% or more of the entire observed precipitates, the number of precipitates having a small particle size is small, and in the subsequent secondary cold working step S04, the precipitates It is possible to suppress re-dissolution and to produce a copper alloy wire excellent in conductivity.
In addition, since the average particle size of the precipitates is 15 nm or more, the precipitates are sufficiently precipitated, the conductivity can be improved, and the strength and repeated bending characteristics can be improved.
Therefore, it can be used as a wiring cable in a portion where bending or twisting of a robot arm or the like is repeatedly loaded.

  In the present embodiment, the composition of the copper alloy wire is Co: 0.12 mass% or more and 0.40 mass% or less, P: 0.040 mass% or more and 0.16 mass% or less, Sn: 0.005 mass% Since the content is 0.70% by mass or less and the balance is Cu and unavoidable impurities, precipitates made of a compound of Co and P are dispersed in the copper matrix, and the strength, conductivity Can be improved. Moreover, since Sn is contained in the range of 0.005 mass% or more and 0.70 mass% or less, the strength can be further improved by solid solution strengthening, and the strength and repeated bending characteristics can be improved. Can do. Moreover, heat resistance and corrosion resistance are also improved.

Further, in the present embodiment, since Ni is further contained in an amount of 0.01% by mass or more and 0.15% by mass or less, coarsening of crystal grains can be suppressed, and strength and repeated bending characteristics can be further improved.
Moreover, in this embodiment, Zn; 0.002 mass% or more and 0.5 mass% or less, Mg; 0.002 mass% or more and 0.25 mass% or less, Ag; 0.002 mass% or more and 0.25 mass% %, Zr: 0.001% by mass or more and 0.1% by mass or less, and any one or more of Zn, Mg, Ag, and Zr are contained in sulfur (S) and a compound. By forming, it is possible to suppress the solid solution of sulfur (S) in the parent phase of copper, and it is possible to suppress deterioration of mechanical properties such as the strength of the copper alloy wire.

  In the present embodiment, after the secondary cold working step S04, a twisted wire processing step S05 in which a plurality of copper alloy wires are twisted to form a cable conductor, and the cable conductor is heat treated for strain relief. The final heat treatment step S06, so that the strain accumulated in the secondary cold working step S04 and the stranded wire working step S05 can be released by the final heat treatment step S06, and bendability, elongation, etc. Can be improved. In the final heat treatment step S06, the heat treatment temperature is set in the range of 100 ° C. or more and 400 ° C. or less, so there is no possibility that the copper alloy wires are in close contact with each other.

  Furthermore, in this embodiment, since the copper rough drawing wire 50 is produced by the continuous casting rolling process S01, the copper rough drawing wire 50 can be produced efficiently. Moreover, since it will be hold | maintained for a fixed time, for example in a high temperature state of 800-1000 degreeC, elements, such as Co and P, will be dissolved in the mother phase of copper, and it is necessary to perform solution treatment separately. There is no.

As mentioned above, although embodiment of this invention was described, this invention is not limited to this, It can change suitably in the range which does not deviate from the technical idea of the invention.
For example, in the present embodiment, the copper alloy wire constituting the wiring cable for the robot has been described. However, the present invention is not limited to this, and may be a wiring cable used for a portable terminal, a hinge portion of a PC, or the like. .

Moreover, although this embodiment demonstrated as what manufactures a copper rough drawing wire by a continuous casting rolling process, it is not limited to this, A cylindrical ingot (billet) is produced and this ingot is extruded. -You may produce a rough copper wire by cold working. However, when a copper roughing wire is produced by an extrusion method, it is necessary to perform a solution treatment separately. Furthermore, even if it is a case where it manufactures by a continuous casting rolling process, you may implement a solution treatment with respect to a copper rough drawing wire.
In the present embodiment, the continuous casting and rolling process is described as being performed using the belt wheel type casting machine shown in FIG. 2, but the present invention is not limited to this, and other continuous casting methods are adopted. Also good.

  Below, the result of the confirmation experiment performed in order to confirm the effectiveness of this invention is demonstrated.

(Examples of the present invention and comparative examples)
Using a continuous casting and rolling facility equipped with a belt wheel type continuous casting machine, a copper roughing wire (diameter 8 mm) made of a copper alloy having the composition shown in Table 1 was produced. The copper rough wire was subjected to primary cold working to a diameter of 0.9 mm, and then subjected to aging heat treatment under the conditions shown in Table 1. Thereafter, secondary cold working was performed to obtain a diameter of 0.08 mm, and a final heat treatment was performed under the conditions shown in Table 1.

(Conventional example)
As Conventional Example 1, soft copper of tough pitch copper having an outer diameter of 0.08 mm was prepared.
As Conventional Example 2, hard copper of Sn-containing copper having an outer diameter of 0.08 mm was prepared.
As Conventional Example 3, a soft copper of Sn-containing copper having an outer diameter of 0.08 mm was prepared.

(Observation of precipitates after aging heat treatment)
About the example of this invention, the deposit was observed using the copper wire after an aging heat processing. The observation of the precipitates was performed using transmission electron images of a transmission electron microscope (model name: TEM: manufactured by Hitachi, H-800, HF-2000, HF-2200, and JEOL JEM-2010F). The equivalent particle size was calculated from the area. Note that the magnification was 150,000 times and 750,000 times, and the observation was performed in the measurement visual fields of about 4 × 10 ⁵ nm ² and about 2 × 10 ⁴ nm ² , respectively. Then, the average particle size of the precipitates and the proportion of the precipitates having a particle size of 5 nm or more among the observed precipitates were calculated. The results are shown in Table 2.

(Flexibility)
Flexibility was evaluated using the copper alloy wires (outer diameter 0.08 mm) of the present invention example, comparative example, and conventional example. In the bending test, using the bending test method shown in FIG. 3, the bending portion 61 has an R of 5 mm, a load (weight 62) of 20 g, is bent 180 ° and returned to its original position twice. The bending was repeated until breakage occurred. The evaluation results are shown in Table 2.

(conductivity)
The electrical conductivity was measured using the copper alloy wires (outer diameter 0.08 mm) of the present invention example, comparative example, and conventional example after the final heat treatment. The conductivity was measured by a double bridge method in accordance with JIS H 0505. The evaluation results are shown in Table 2.

In Examples 1-19 of the present invention, the number of precipitates having an average particle size of 15 nm or more and a particle size of 5 nm or more observed by observing the cross-sectional structure immediately after aging heat treatment was observed. It is confirmed that it is 80% or more of the entire precipitate. Flexibility is superior to Conventional Examples 1 and 2, and conductivity is 70% IACS or higher.
On the other hand, Comparative Example 1-3 in which the number of precipitates having a particle size of 5 nm or more was less than 80% of the total precipitates observed (in Comparative Examples 2 and 3, the average particle size of the precipitates was At less than 15 nm, the flexibility and conductivity are poor.
From the above, according to the present invention example, it was confirmed that a copper alloy wire excellent in conductivity and repeated bending characteristics can be obtained.

Claims (6)

Co: 0.12 mass% or more and 0.40 mass% or less, P: 0.040 mass% or more and 0.16 mass% or less, Sn; 0.005 mass% or more and 0.70 mass% or less, and the balance is Cu And a precipitation-strengthened copper alloy having a composition that is an inevitable impurity,
The average particle size of precipitates observed by cross-sectional structure observation immediately after performing the aging heat treatment is 15 nm or more, and the number of precipitates having a particle size of 5 nm or more is 80% or more of the total precipitates observed. Has been cold worked after the aging heat treatment,
The outer diameter is 0.015 mm or more and 0.2 mm or less,
When the bending part R is 5 mm, the load is 20 g, the number of times of 180 ° bending and returning to the original position is counted twice, and the bending is repeated until the breaking occurs, until the breaking occurs The copper alloy wire is characterized in that the number of bendings is 1154 times or more.   2. The copper alloy wire according to claim 1, wherein the P content is in the range of 0.097 mass% or more and 0.16 mass% or less.   3. The copper alloy wire according to claim 1, wherein the precipitation-strengthened copper alloy further includes Ni; 0.01% by mass or more and 0.15% by mass or less.   The precipitation-strengthening-type copper alloy further contains Zn: 0.002 mass% to 0.5 mass%, Mg: 0.002 mass% to 0.25 mass%, Ag; 0.002 mass% to 0.25 It contains any 1 type (s) or 2 or more types among the mass% or less, Zr; 0.001 mass% or more and 0.1 mass% or less, It is any one of Claims 1-3 characterized by the above-mentioned. Copper alloy wire. It is a manufacturing method of the copper alloy wire according to any one of claims 1 to 4,
A continuous casting and rolling process for continuously producing copper rough wire,
A primary cold process for obtaining a copper wire by cold-working the copper roughing wire produced by the continuous casting and rolling process;
An aging heat treatment step of performing an aging heat treatment on the copper wire;
A secondary cold working step performed after this aging heat treatment step,
The average particle size of precipitates observed by observation of the cross-sectional structure immediately after performing the aging heat treatment step is 15 nm or more, and the number of precipitates having a particle size of 5 nm or more is 80% or more of the total precipitates observed. The manufacturing method of the copper alloy wire characterized by these.   A stranded wire characterized by having a structure in which a plurality of the copper alloy wires according to any one of claims 1 to 4 are twisted together.

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