JPH02267811A - Copper composite wire material for extra fine wire - Google Patents

Abstract

PURPOSE:To increase mechanical strength such as rupture strength and elonga tion and conductivity, and suppress die abrasion by coating a core wire part consisting of a specified copper alloy with a coating part consisting of Cu having a purity of 99.9wt.% or more at a sectional area ratio of less than 40%. CONSTITUTION:A copper wire material for extra fine wire is formed of a core wire part consisting of copper alloy and a coating part consisting of Cu. The core wire part consisting of copper alloy contains 0.05-0.3wt.% of Ag and 0.003-0.01wt.% of Zr, with the remaining being Cu and unavoidable impurities, and the oxygen content is regulated to less than 10ppm. The coating part consisting of Cu has a Cu purity of 99.9wt.% or more and coats the core wire part at a sectional area ratio of less than 40%. Therefore, semi-softening processing can be easily conducted, and an extra fine wire excellent in mechani cal strength such as rupture strength and elongation and conductivity can be obtained. The abrasion of a die for drawing the extra fine wire copper compos ite wire material can be also suppressed.

Description

[Detailed Description of the Invention] [Industrial Field of Application] The present invention is used as a thin copper wire or a winding core wire for magnetic heads, etc., and has excellent mechanical strength, electrical conductivity, and heat resistance, and is easy to use during wire drawing. The wear of the die is reduced, and the wire diameter is reduced to 0.
, relates to a copper composite wire material for ultra-fine wires suitable for ultra-fine wires of 1 mm or less.

[Prior Art] Recently, with the development of electronic devices, in the field of copper fine wire and winding core wire for magnetic heads (core wire for magnet wire), ultra-fine copper wire with a wire diameter of 0 mm or less, especially 50μ
Demand for ultra-fine copper wire of less than 100 ft (m) in diameter is rapidly increasing.

By the way, as copper wires become finer, wire breakage becomes more likely to occur during the winding process. For this reason, ultra-fine copper wire has the excellent conductivity and appropriate softness (elongation) required for ordinary thin copper wire.
In addition, high breaking strength is required.

Conventionally, in order to obtain appropriate elongation and high breaking strength, semi-softening treatment has been applied to ultrafine copper wire as drawn. In this case, if the complete softening temperature of the ultra-fine copper wire is low, such as when the ultra-fine copper wire is made of copper wire material, the ultra-fine copper wire will be in a semi-softened state when enamel is baked on the circumferential surface of the ultra-fine copper wire in a later process. It changes from to completely softened state. Therefore, desired breaking strength cannot be obtained.

For this reason, conventional ultrafine copper wires include copper alloy wires containing Zr, copper alloy wires containing Ag or sb, etc., copper alloy wires containing Sn, etc., and precipitated copper alloy wires such as Cr copper. Copper alloy wire with a high softening temperature is used.

[Problems to be Solved by the Invention] However, since the above-mentioned copper alloy wires all have high hardness, they have the disadvantage that the dies used during wire drawing are more abraded than in the case of pure copper.

Furthermore, all copper alloy wires also have the disadvantage of having lower conductivity than pure copper. Additionally, each copper alloy wire has its own drawbacks. For example, in the case of Zr-containing copper alloy wire,
Since the complete softening temperature is too high, annealing treatment to obtain semi-softening properties is difficult.

In addition, in the case of copper alloy wire containing Ag or sb, etc.
It has excellent electrical conductivity similar to pure copper and has a moderate complete softening temperature, but the annealing temperature range in which a semi-softened state can be obtained is narrow, so the desired mechanical strength can be obtained by semi-softening treatment. is difficult.

The present invention has been made in view of such problems, and includes:
It is easy to undergo semi-softening treatment, has excellent mechanical properties such as breaking strength and elongation after treatment, and has excellent electrical conductivity.Furthermore, die wear during wire drawing is comparable to that of pure copper. The purpose of the present invention is to provide a copper composite wire material for ultra-fine wires that can suppress the

[Means for Solving the Problems] The copper composite wire for ultrafine wire according to the present invention has a wire rod of 0.05 to 0.05.
3% by weight Ag and 0.003-0.01% by weight Z
A core wire portion made of a copper alloy containing r, the remainder being Cu and unavoidable impurities, and the oxygen content regulated to 10 ppm or less, and a core wire portion made of Cu with a purity of 99.9% by weight or more and 40% of the core wire portion. It is characterized by having a covering portion covering the following cross-sectional area ratios.

[Function] As mentioned above, the ultrafine copper wire made of an Ag-containing copper alloy has excellent mechanical strength such as breaking strength and elongation, and also has excellent electrical conductivity. However, the range of annealing conditions under which this ultra-fine copper wire can be semi-softened is extremely narrow. That is, when the annealing temperature is held constant, the appropriate annealing time range is extremely narrow, and when the annealing time is held constant, the appropriate annealing temperature range is extremely narrow. For this reason, variations in quality are likely to occur during 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, as mentioned above, since the complete softening temperature is too high, the annealing process itself for semi-softening process is difficult.

In order to eliminate the drawbacks of the above-mentioned Ag-containing copper alloy, the present inventors added Zr, which has the effect of widening the range of appropriate annealing conditions, and manufactured various copper alloy materials with different amounts of Zr added. An ultra-fine copper wire with a wire diameter of 30 μm was processed from this copper alloy material, and annealing experiments were repeatedly performed on this ultra-fine copper wire. As a result, the copper alloy wire obtained by adding a predetermined amount of Ag and Zr has an appropriate range of annealing conditions for semi-softening treatment without impairing the excellent mechanical properties and conductivity of the Ag-containing copper alloy wire. I found it to be wider. In addition, a composite wire in which the copper alloy wire containing Ag and Zr is used as a core wire and the surrounding surface is coated with pure copper maintains the above-mentioned characteristics, and
It was found that the deterioration of the die during wire drawing was as slight as in the case of pure copper. The present invention has been made based on such knowledge.

Next, the reason for limiting the composition of each component of the core wire portion of the copper composite wire for ultra-fine wire according to the present invention will be explained.

K■ If the Ag content is less than 0.05% by weight, the effect of increasing the breaking strength by raising the complete softening temperature of the copper alloy to the necessary and sufficient level will not be achieved, and complete softening will not occur during enamel baking after semi-softening treatment. It becomes a state. For this reason, desired breaking strength cannot be obtained.

On the other hand, if the Ag content exceeds 0.3% by weight, expensive A
The addition of g significantly increases the manufacturing cost and deteriorates the conductivity of the core wire portion. Therefore, the Ag content is 0
．． 05 to 0.3% by weight.

, ZJL If the Zr content is 0.003% by weight and no grooves are present, the effect of expanding the range of appropriate annealing conditions due to the addition of 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 deteriorates and the annealing temperature becomes high, making annealing difficult. As a result, the Zr content is 0.00
3 to 0.01% by weight.

If the oxygen content exceeds 10 ppm, this oxygen will combine with Zr, etc. in the core wire, increasing the amount of oxides such as ZrO□, making wire breakage more likely to occur during the wire drawing process into ultra-fine wire. . For this reason, the oxygen content is regulated to 10 ppm or less.

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

° no' (If the purity of the pure copper constituting the sheath is less than 99.9% by weight, the hardness of the sheath will increase after semi-softening treatment is applied to the core wire, resulting in die wear during wire drawing.) Therefore, the purity of pure copper in the coated portion is set to 99.9% by weight or more.

When semi-softening treatment is applied to the Ag-Zr-Cu alloy of the core wire part 1,
The pure copper in the coating becomes completely softened. For this reason, if the coverage ratio of the covering portion to the core wire portion exceeds 40% in terms of cross-sectional area ratio, the breaking strength of the resulting ultrafine wire will be low, making it impossible to obtain desired mechanical properties. Therefore, the coverage of the covering portion is set to 40% or less of the entire composite wire in terms of cross-sectional area ratio.

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

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

Next, by repeatedly performing intermediate heat treatment and wire drawing, an ultrafine wire with a wire diameter of 30 μm was formed from this rod. As a result, in Comparative Example 9, wire breakage occurred frequently during wire drawing.

Therefore, Comparative Example 9 could not be evaluated further.

Next, repeated annealing experiments were performed on each of the ultrafine wires of Examples 1 to 3 and Comparative Examples 1 to 8, each having a wire diameter of 30 μm, and the results showed that the breaking strength was 32 kg f /- or more and the elongation was 10% or more. The annealing temperature at which mechanical strength was obtained was investigated.

However, at this time, a heating furnace with a furnace length of 90 cm was used, and the ultrafine wires of Examples 1 to 3 and Comparative Examples 1 to 8 were inserted into this heating furnace at a line speed of 60 m/min.

As a result, Comparative Example 1 could not obtain the desired mechanical strength. Therefore, except for this comparative example 1, Example 1
The annealing temperature range in which the desired mechanical strength was obtained in Comparative Examples 2 to 3 and Comparative Examples 2 to 8 is shown in Table 2 below. Further, the electrical conductivity of the semi-softened ultrafine wire obtained by this annealing is also shown in Table 2.

Furthermore, using a die with a die diameter of 30 μm, we measured the amount of ultra-fine wire that could be drawn until the die diameter increased by 1 μm due to wear during wire drawing to determine the degree of die wear. was evaluated.

The evaluation results of die wear are also shown in Table 2, with cases where the amount of extra-fine wire drawn was 30 kg or more represented by Q and cases where the amount was less than 120 kg.

Table 2: The annealing temperature to obtain a semi-softened state is 30°C within the temperature range of 400 to 500'C.
It is preferable that there is a temperature range of C or more.

Further, it is preferable that the conductivity is 95% IACS or higher. Examples 1 to 3 all satisfied these desired conditions, and were able to reliably obtain extremely excellent mechanical and electrical properties.

On the other hand, Comparative Examples 1 to 9, which fall outside the scope of the claims of the present invention, were not satisfactory in any one or more of wire drawability, appropriate annealing temperature, processing temperature range, electrical conductivity, and die wear. .

[Effects of the Invention] As explained above, the copper composite wire for ultrafine wires 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 contains oxygen. Content 10pp
A core wire made of a copper alloy regulated to a purity of 99.
．． Since the M portion is made of 9% by weight or more of pure copper, the semi-softening treatment can be easily performed. This makes it possible to obtain an ultrafine wire with excellent mechanical strength such as breaking strength and elongation, as well as electrical conductivity. Furthermore, the wear of dies for wire drawing of this copper composite wire material for ultra-fine wires is extremely small.

Claims (1)

[Claims] (1) 0.05 to 0.3 wt% Ag and 0.003
A core wire portion made of a copper alloy containing 0.01% by weight of Zr, the remainder being Cu and unavoidable impurities, and the oxygen content regulated to 10 ppm or less, and a purity of 99.3% by weight.
A copper composite wire material for ultra-fine wires, comprising a covering part made of the above-mentioned Cu and covering the core part with a cross-sectional area ratio of 40% or less.