JPH0644412B2 - Copper composite wire for extra fine wire - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention is used as a copper thin wire or a winding core wire for a magnetic head, and has excellent mechanical strength, conductivity and heat resistance, and at the time of wire drawing. Wear of the die is reduced and the wire diameter is 0.1 m
The present invention relates to a copper composite wire material suitable for ultrafine wires of m or less.

[Prior Art] In recent years, along with the development of electronic devices, in the fields of copper fine wires and winding wires for magnetic heads (core wires for magnet wires), etc., ultrafine copper wires with a diameter of 0.1 mm or less, especially 50 μm or less. The demand for ultra-fine copper wire is rapidly increasing.

By the way, as the copper wire becomes finer, disconnection is likely to occur during the winding process. Therefore, the ultra-thin copper wire has the excellent conductivity and moderate softness (elongation) required for ordinary copper wires.
In addition, high breaking strength is required.

Conventionally, in order to obtain appropriate elongation and high breaking strength, semi-softening treatment is applied to extra fine copper wire after drawn. In this case, if the ultra-fine copper wire has a low complete softening temperature as in the case of being composed of a copper wire material, the ultra-fine copper wire is in a semi-softened state when the enamel is baked on the peripheral surface of the ultra-fine copper wire in a later step. Changes to a completely softened state. Therefore, the desired breaking strength cannot be obtained.

Therefore, conventionally, as the ultrafine copper wire, a copper alloy wire rod containing Zr, a copper alloy wire rod containing Ag or Sb, a copper alloy wire rod containing Sn, etc., and a precipitation-type copper alloy wire rod containing Cr copper etc. Copper alloy wire with a high softening temperature is used.

[Problems to be Solved by the Invention] However, since all the above-mentioned copper alloy wire rods have high hardness, there is a drawback in that the die used during wire drawing is more worn than in the case of pure copper. Further, there is a drawback that any of the copper alloy wire rods has lower conductivity than pure copper.
Moreover, each copper alloy wire has its own drawbacks. For example, Z
In the case of a copper alloy wire containing r, the complete softening temperature is too high, so that it is difficult to perform the annealing treatment for obtaining the semi-softening property. Further, in the case of a copper alloy wire containing Ag or Sb, the conductivity is as good as that of pure copper, and it has an appropriate complete softening temperature, but the semi-softening treatment gives a desired mechanical strength. Hard to get.

The present invention has been made in view of such problems,
Semi-softening treatment is easy, mechanical properties such as rupture strength and elongation after treatment are excellent, and conductivity is excellent, and die wear during wire drawing is similar to that of pure copper. It is an object of the present invention to provide a copper composite wire material for ultrafine wires that can be suppressed to a low level.

[Means for Solving the Problems] The copper composite wire for ultrafine wire according to the present invention contains 0.05 to 0.3% by weight of Ag and 0.003 to 0.01% by weight of Zr, and the balance is Cu and inevitable impurities, Oxygen content 10pp
The core wire made of copper alloy regulated to m or less and the purity of 99.9
It is characterized by having a coating portion made of Cu in an amount of at least wt% and covering the core wire portion at a sectional area ratio of 40% or less.

[Operation] As described above, the ultrafine copper wire made of the Ag-containing copper alloy has excellent mechanical strength such as breaking strength and elongation, and also has excellent conductivity. However, this ultrafine copper wire has an extremely narrow range of annealing conditions that can be semi-softened. That is, when the annealing temperature is constant, the proper annealing time range is extremely narrow, and when the annealing time is constant, the proper annealing temperature range is extremely narrow. For this reason, variations in quality are likely to occur in the annealing process for semi-softening treatment.

On the other hand, the ultrafine copper wire made of a Zr-containing alloy has the advantage that the range of appropriate annealing conditions for semi-softening treatment is wide. However, since the complete softening temperature is too high as described above, the annealing treatment itself for the semi-softening treatment is difficult.

The inventors of the present application, based on the above-mentioned Ag-containing copper alloy, add Zr having the action of widening the range of appropriate annealing conditions in order to eliminate the drawbacks, and manufacture various copper alloy materials with different addition amounts. An ultrafine copper wire having a wire diameter of 30 μm was machined from this copper alloy material, and an annealing test was repeatedly performed on this ultrafine copper wire. As a result, the copper alloy wire obtained by adding a predetermined amount of As and Zr has an appropriate annealing condition range for semi-softening treatment without impairing the excellent mechanical properties and conductivity of the Ag-containing copper alloy wire. I found that it would become wider. In addition, the composite wire material in which the copper alloy wire material containing Ag and Zr is used as a core wire and the peripheral surface thereof is coated with pure copper maintains the above-mentioned characteristics,
It was found that the die deterioration during wire drawing was as slight as that of pure copper. The present invention has been made based on such findings.

Next, the reasons for limiting the composition of each component of the core portion of the copper composite wire for ultrafine wire according to the present invention will be described.

Ag If the Ag content is less than 0.05% by weight, the effect of increasing the rupture strength by sufficient and sufficient softening temperature of the copper alloy cannot be obtained, resulting in a fully softened state during enamel baking after the semi-softening treatment. I will end up. Therefore, the desired breaking strength cannot be obtained. On the other hand, when the content of Ag exceeds 0.3% by weight, the manufacturing cost is significantly increased due to the addition of expensive Ag, and the conductivity of the core wire portion is deteriorated. Therefore, A
The content of g is 0.05 to 0.3% by weight.

Zr If the Zr content is less than 0.003% by weight, the effect of expanding the range of appropriate annealing conditions by adding Zr cannot be obtained. On the other hand, when the content of Zr exceeds 0.01% by weight, the conductivity of the core wire portion is deteriorated and the annealing temperature becomes high, which makes annealing difficult. Therefore, the content of Zr is 0.003 to 0.01
Weight%

Oxygen When the oxygen content exceeds 10 ppm, the oxygen binds to Zr and the like in the core wire to increase the amount of oxides such as ZrO ₂ and the disconnection easily occurs in the process of drawing ultrafine wire. Therefore, the oxygen content is limited to 10 ppm or less.

Next, the composition of the coating portion and the reasons for limiting the coverage will be described.

Purity of Cu in the coating part If the purity of pure copper constituting the coating part is less than 99.9% by weight, the hardness of the coating part becomes high after the core wire part is subjected to semi-softening treatment, so that the die wear during wire drawing. It will be noticeable.
Therefore, the purity of pure copper in the coating is 99.9% by weight or more.

Covering rate of the core portion of the coated portion When the Ag-Zr-Cu alloy of the core portion is subjected to the semi-softening treatment,
The pure copper in the coating is completely softened. For this reason, if the coverage of the core portion of the coating portion exceeds 40% in terms of cross-sectional area ratio, the breaking strength of the obtained ultrafine wire will be low and desired mechanical properties cannot be obtained. Therefore, the coverage of the covering portion is 40% or less of the total area of the composite wire rod in terms of cross-sectional area ratio.

[Examples] Next, examples of the present invention will be described.

First, a copper-copper alloy composite rod having a diameter of 20 mm and the components and coverage shown in Table 1 below was manufactured.

Next, the intermediate heat treatment and the wire drawing process were repeated to form an ultrafine wire having a wire diameter of 30 μm from this rod.
As a result, in Comparative Example 9, disconnection frequently occurred during wire drawing. Therefore, Comparative Example 9 could not be evaluated thereafter.

Next, repeated annealing experiments were performed on the ultrafine wires of Examples 1 to 3 and Comparative Examples 1 to 8 having a wire diameter of 30 μm,
The annealing temperature at which the breaking strength is 32 kgf / mm ² or more and the elongation is 10% or more and the mechanical strength is obtained was examined.

However, at this time, a heating furnace having a furnace length of 90 cm was used, and the ultrafine wires of Examples 1 to 3 and Comparative Examples 1 to 8 were used in the heating furnace.
It was inserted at a linear velocity of m / min.

As a result, Comparative Example 1 could not obtain the desired mechanical strength. Therefore, except for this Comparative Example 1, Example 1
Table 2 below shows the annealing temperature ranges in which the desired mechanical strengths were obtained in Comparative Examples 2 to 3 and Comparative Examples 2 to 8. In addition, Table 2 also shows the conductivity of the ultra-soft wire in the semi-softened state obtained by this annealing. Furthermore, by using a die with a die diameter of 30 μm, measure the amount of extra fine wire that could be drawn until the die diameter was expanded by 1 μm due to wear during wire drawing to determine the degree of die wear. evaluated. The evaluation results of die wear are also shown in Table 2 when the amount of ultrafine wire that can be drawn is 30 kg or more, and when it is less than 20 kg, it is represented by x.

If the annealing temperature at which a semi-softened state is obtained is too low, it will be in a completely softened state in the post-process, and if it is too high, it will be difficult to process, so there may be a temperature range of 30 ° C or higher within the temperature range of 400 to 500 ° C. preferable. Further, the conductivity is preferably 95% IACS or more. All of Examples 1 to 3 satisfied this desired condition, and it was possible to reliably obtain extremely excellent mechanical properties and electrical properties.

On the other hand, in Comparative Examples 1 to 9 which are out of the claims of the present invention, any one or more of the wire drawing workability, the proper annealing temperature, the processing temperature range, the conductivity, and the wear of the die was not satisfied. .

[Advantages of the Invention] As described above, the copper composite wire for ultrafine wire according to the present invention has 0.05 to 0.3% by weight of Ag and 0.003 to 0.01% by weight.
Core wire made of a copper alloy containing Zr and having an oxygen content regulated to 10 ppm or less, and a coating made of pure copper with a purity of 99.9% by weight or more for covering the peripheral surface of the core wire with a sectional area ratio of 40% or less. Since it has a part, the semi-softening treatment can be easily performed. This makes it possible to obtain an ultrafine wire having excellent mechanical strength such as breaking strength and elongation and conductivity. Further, the wear of the die for drawing the copper composite wire for ultrafine wire is extremely small.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Mamoru Aoyagi 1-5-1 Kiba, Koto-ku, Tokyo Fujikura Electric Wire Co., Ltd. (56) References JP-A-56-76115 (JP, A) JP-A-SHO 61-201762 (JP, A) JP-A-63-13205 (JP, A) JP-A-63-245811 (JP, A) Actual development Sho-58-134877 (JP, U)

Claims (1)

[Claims] 1. Ag to 0.05 to 0.3% by weight and 0.003 to 0.
A core wire portion containing 01 wt% Zr, the balance being Cu and unavoidable impurities, and a copper alloy having an oxygen content regulated to 10 ppm or less, and a core portion made of Cu having a purity of 99.9 wt% or more. A copper composite wire material for extra fine wires, characterized in that it has a covering portion covering at a cross-sectional area ratio of 40% or less.