JPH0644413B2 - Copper alloy composite wire for extra fine wire - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention is used as a thin copper 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 alloy wire rod for ultrafine wires 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, Sb or the like, the conductivity is as good as that of pure copper, and it has an appropriate complete softening temperature, but the annealing temperature at which a semisoftened state is obtained is narrow. Therefore, it is difficult to obtain a desired mechanical strength by the semi-softening treatment.

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. An object of the present invention is to provide a copper alloy composite wire for ultrafine wires that can be suppressed to a low level.

[Means for Solving the Problems] The copper alloy composite wire for ultrafine wires according to the present invention is 0.003 to 0.0
A core portion made of a copper alloy containing 12% by weight of Zr, the balance being Cu and inevitable impurities, and having an oxygen content regulated to 10 ppm or less, and 0.05 to 0.3 formed around the core portion. The coating has a weight percentage of Ag, the balance being Cu and unavoidable impurities, and a coating made of a copper alloy having an oxygen content regulated to 10 ppm or less, and the cross-sectional area ratio of the coating is 40 to 60%. Is characterized in that.

[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, an ultrafine copper wire made of a Zr-containing copper 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 produced various composite wire rods using the Ag-containing copper alloy and the Zr-containing copper alloy described above, machined the ultrafine wires with a wire diameter of 30 μm from the composite wire rod, and The annealing test was repeated. As a result, the composite wire obtained by coating the peripheral surface of the copper alloy wire containing a predetermined amount of Zr with the copper alloy containing a predetermined amount of Ag has excellent mechanical properties and electrical conductivity of the Ag containing copper alloy wire. It has been found that the range of appropriate annealing conditions for the semi-softening treatment is widened without any loss. Further, it was also found that the deterioration of the die of this composite wire rod 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 copper alloy composite wire for ultrafine wire according to the present invention will be described.

Zr When the Zr content of the core wire portion is less than 0.003% by weight, Z
The effect of expanding the range of appropriate annealing conditions by adding r cannot be obtained. On the other hand, when the content of Zr exceeds 0.012% by weight, the conductivity of the ultrafine wire deteriorates and the annealing temperature becomes high, which makes annealing difficult. As a result, the Zr content is 0.003
To 0.012% by weight.

Ag If the content of Ag in the coating is less than 0.05% by weight, the effect of increasing the breaking strength by fully and fully softening the copper alloy is not obtained, and the fully softened state is obtained when the enamel is baked after the semi-softening treatment. Become. Therefore, the desired breaking strength cannot be obtained. On the other hand, when the content of Ag exceeds 0.3% by weight, the addition of expensive Ag causes a significant increase in the manufacturing cost and also deteriorates the conductivity of the ultrafine wire. Therefore, the content of Ag is set to 0.05 to 0.3% by weight.

Oxygen If the oxygen content of the core wire and the coating exceeds 10 ppm,
Since this oxygen increases the amount of impurities contained in the oxide formed by combining with the impurities in the alloy wire, disconnection is likely to occur in the step of drawing an ultrafine wire. Therefore, the oxygen content is
Restrict to 10ppm or less.

Coverage of the core portion of the covering portion If the coverage of the core portion of the covering portion is less than 40% in terms of cross-sectional area ratio, desired conductivity cannot be obtained. On the other hand, when the coverage exceeds 60%, the proper annealing range becomes narrower,
The semi-softening treatment performed to obtain the desired mechanical strength becomes extremely difficult. Therefore, the coverage of the core portion of the coating portion is 40 to 60% of the total area of the composite wire material in terms of cross-sectional area ratio.

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

First, a copper alloy composite wire 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 Examples 5 and 6, wire breakage occurred frequently during wire drawing. Therefore, Comparative Examples 5 and 6 could not be evaluated thereafter.

Next, repeated annealing tests were performed on the ultrafine wires of Examples 1 to 3 and Comparative Examples 1 to 4 and Comparative Example 7 having a wire diameter of 30 μm, and the breaking strength was 32 kgf / mm ² or more and the elongation percentage was The annealing temperature at which a mechanical strength of 10% or more was obtained was investigated.

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 4 and Comparative Example 7 were inserted into the heating furnace at a linear velocity of 60 m / min.

Table 2 below shows the annealing temperature range in which the above-mentioned desired mechanical strength obtained as a result was obtained. In addition, Table 2 also shows the conductivity of the ultra-soft wire in the semi-softened state obtained by this annealing.

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, Comparative Examples 1 to 7, which are out of the scope of the claims of the present invention, were unable to satisfy at least one of the wire drawing workability, the proper annealing temperature, the processing temperature range, and the conductivity.

[Effects of the Invention] As described above, the copper alloy composite wire for ultrafine wires according to the present invention contains a core wire portion made of a copper alloy containing 0.003 to 0.012% by weight of Zr and having an oxygen content of 10 ppm or less. , 0.0
Since it has a coating made of a copper alloy containing 5 to 0.3% by weight of Ag and limiting the oxygen content to 10 ppm or less,
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 alloy composite wire for ultrafine wire is extremely small.

Front Page Continuation (72) Inventor Mamoru Aoyagi 1-5-1, Kiba, Koto-ku, Tokyo Within Fujikura Electric Wire Co., Ltd. (56) Reference JP-A-56-76115 (JP, A) JP-A-60-207217 (JP, A) JP-A-61-201762 (JP, A)

Claims (1)

[Claims] 1. A 0.003 to 0.012 wt% Zr content, the balance being Cu and inevitable impurities, and an oxygen content of 10 pp.
A core wire made of a copper alloy regulated to m or less and 0.05 to 0.3% by weight of Ag formed around the core wire, the balance being Cu and inevitable impurities, and an oxygen content of 10 ppm or less. A copper alloy composite wire for extra fine wires, comprising a regulated coating portion made of a copper alloy, wherein the coating material has a cross-sectional area ratio of 40 to 60%.