JPH02223104A - Copper-group member and manufacture thereof - Google Patents

Abstract

PURPOSE:To permit to obtain the member in the title having its excellent mechanical strength and its high conductivity by having a reinforced copper alloy layer made of easily oxidizable elements or the compound thereof, a high-purity copper layer being excellent in its electroconductivity and an anti-diffusing layer made of the metal oxide of the elements added as a part of the material of the reinforced copper alloy layer therebetween. CONSTITUTION:A copper-group wire-rod 1 has a high-purity copper layer 4 formed on the outer circumference of a reinforced copper alloy layer 2 made of 0.8wt.% of Cr, 0.2wt.% of Zr and a Cu alloy via an anti-diffusing layer 3 made of oxides of Cr and Zr. And the anti-diffusing layer 3 made of firm metal oxides is formed at the interface between the high-purity copper layer 4 and the reinforced copper alloy layer 2, whereby the added elements present in the reinforced copper alloy layer 2 is prevented from the diffusion thereof into the high-purity copper layer 4 when heat treatment is made and thereafter when heat is impressed upon the copper-group member. This makes it possible to maintain the conductivity of the high-purity copper layer 4, while the strength of the reinforced copper alloy layer 2 can be easily maintained, for example, by cold-work after its heat treatment, and then working and hardening it for recovering its strength.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to a copper-based member having both excellent electrical conductivity and strength, and a method for manufacturing the same.

(Prior art) Copper-based materials have excellent electrical conductivity, so they are used in applications that require low electrical resistance, such as lead frames in semiconductor devices and stabilizing materials in superconducting wires, as well as in power transmission lines that carry large amounts of current. It is used as a conductive material for various purposes.

For example, pure copper has the second highest electrical conductivity after silver, so it is used in places where highly low electrical resistance is required. However, pure copper has relatively low mechanical strength, so when a certain level of strength is required, it is necessary to use stainless steel or the like as a tension member.

On the other hand, alloys in which metal elements such as tin, nickel, silicon, titanium, phosphorus, iron, and cobalt are added to copper are
It is called a solid solution strengthened copper alloy and has higher mechanical strength than pure copper. However, these solid solution strengthened copper alloys have lower electrical conductivity than pure copper; for example, silicon is added to copper by 0.4
Copper alloy with 0 wt% addition has a conductivity of 100 of the universal standard mild steel.
% (hereinafter abbreviated as 1AC8 ratio %), the conductivity decreases to about 45%.

Further, an alloy in which alumina powder or the like is dispersed in steel is called a particle dispersion strengthened copper alloy, and it can obtain high mechanical strength like the solid solution strengthened copper alloy.

Although this particle dispersion strengthened copper alloy has higher electrical conductivity than solid solution strengthened copper alloy, it does not have a conductivity comparable to that of pure copper, and also has problems such as low workability. .

Furthermore, similar to the principle of particle dispersion strengthened copper alloys, after processing solid solution strengthened copper alloys into a predetermined shape, elements added for strengthening are precipitated as oxides to improve electrical conductivity. However, when used as a member having a certain size or more, it is difficult to uniformly deposit it inside, and sufficient electrical conductivity cannot be obtained.

(Problems to be Solved by the Invention) As described above, pure copper has excellent electrical conductivity but low mechanical strength, and reinforced copper alloys have excellent mechanical strength but low electrical conductivity.

It is also possible to provide the characteristics of both by integrating pure copper and reinforced copper alloy.
If they are simply integrated, the additive elements and compounds in the strengthened copper alloy will diffuse into pure copper due to heat treatment such as annealing or the application of heat during use, reducing the conductivity of pure copper.

The present invention was made to address the problems of the prior art, and provides a copper-based member and a manufacturing method thereof that share the high electrical conductivity of pure copper and the mechanical strength of reinforced copper alloy without impairing each other. is intended to provide.

[Structures of the Invention] (Means for Solving the Problems) The copper-based member of the present invention includes a reinforced copper alloy layer made of an element or compound that is easily oxidized, a high purity copper layer with excellent electrical conductivity, and a reinforced copper layer. It is characterized by comprising a diffusion prevention layer made of a metal oxide of an additive element of the strengthened copper alloy layer, interposed between the alloy layer and the high-purity copper layer.

Moreover, the first method of manufacturing a copper-based member according to the present invention
The method described above involves combining the reinforced copper alloy layer with the high-purity copper layer to produce a copper-based member that integrates a reinforced copper alloy layer made of an element or compound that is easily oxidized and a high-purity copper layer with excellent electrical conductivity. After forming an oxide layer on the surface or inside of the high-purity copper layer of the structure integrated with the high-purity copper layer, the high-purity copper layer is heated in a vacuum or in a non-oxidizing atmosphere, or at a pressure lower than atmospheric oxygen partial pressure. A diffusion prevention layer made of a metal oxide of an additive element of the reinforced copper alloy layer is formed between the reinforced copper alloy layer and the high-purity copper layer by heat treatment under an oxygen partial pressure that can form oxides on the surface or inside of the layer. The second method is to manufacture a copper-based member by integrating a reinforced copper alloy layer made of an element or compound that is easily oxidized and a high-purity copper layer with excellent electrical conductivity. In this, the high-purity copper layer is formed of high-purity copper containing oxygen, and a structure in which the reinforced copper alloy layer and the high-purity copper layer are integrated,
A diffusion prevention layer made of a metal oxide of an element added to the reinforced copper alloy layer is formed between the reinforced copper alloy layer and the high-purity copper layer by performing heat treatment in a vacuum or a non-oxidizing atmosphere. It is said that

In the present invention, copper alloys forming the reinforced copper alloy layer include Zr-CusZr-Cr-Co-Cu, N
i-Cu −, N1-Zn-Cu5N1-8n-Cu,
5n-Cu 5Sn-P-Cu, Tl-Cu.

Solid solution strengthened copper alloys and spinodal strengthened copper alloys in which easily oxidizable elements such as Be-Cu are added as a solid solution, and particle dispersion strengthened copper alloys with alumina and the like are used.

In addition, as the copper that forms the high-purity copper layer with excellent electrical conductivity, pure copper that basically contains only unavoidable impurities is used, but depending on the method of forming the diffusion prevention layer described later, it may contain a small amount of oxygen. For example, high purity copper containing about 1% by weight or less is used.

The specific structure of the copper-based member of the present invention is as follows: (1) A high-purity copper layer is formed on the surface of the core material made of the above-mentioned reinforced copper alloy, and a diffusion layer made of a metal oxide of an additive element of the reinforced copper alloy is formed at the interface between these layers. ■ A reinforced copper alloy layer is formed on the surface of a core material made of high-purity copper, and a diffusion prevention layer is provided at the interface of these layers in the same way as in ■ ■ High-purity copper and reinforced copper alloy An example of this is a laminate with a diffusion prevention layer provided at the interface thereof in the same way as in (2).

The structure of the copper-based member of the present invention is not limited to these, but any shape or structure may be used as long as it can form an oxide in a part of the high-purity copper layer. It may be something. In addition, the reinforced copper alloy layer has superior corrosion resistance and heat resistance compared to pure copper, so when such properties are required, it is preferable to select a reinforced copper alloy layer as the outer layer. .

The diffusion prevention layer in the copper-based member of the present invention is based on the metal oxide of the added element in the reinforced copper alloy, and even when heat is applied to the copper-based member, the diffusion prevention layer prevents the diffusion in the reinforced copper alloy. Diffusion of additive elements into the high purity copper layer is prevented and electrical conductivity is maintained.

The above-mentioned diffusion prevention layer is formed, for example, as follows.

(A) After or before integrating the reinforced copper alloy layer and the high-purity copper layer, a copper oxide layer is formed on or inside the high-purity copper layer, and then a copper oxide layer is formed in a vacuum or in a non-oxidizing layer. By performing heat treatment in an atmosphere and diffusing oxygen into the high-purity copper layer, the added elements in the strengthened copper alloy react with oxygen at the interface between the strengthened copper alloy layer and the high-purity copper layer, forming a metal oxide layer. form.

(B) After integrating the reinforced copper alloy layer and the high-purity copper layer, high-purity copper is added under an oxygen partial pressure that is lower than the oxygen partial pressure in the atmosphere and that can form copper oxides on or inside the copper layer. A metal oxide layer is formed in the same manner as in (^) above by heat-treating the layer and diffusing oxygen into the high-purity copper layer while forming a copper oxide layer on the surface or inside the high-purity copper layer. do.

(C) Using oxygen-containing high-purity copper as the high-purity copper layer,
A metal oxide layer is formed by performing heat treatment under the same conditions as above (^).

The copper oxide layer in (A) and (B) above is made of CuO5Cu20 alone or a mixture of CuO and Cu20.

Further, by the heat treatment for forming the diffusion prevention layer, impurities inevitably contained in pure copper are also precipitated as oxides, further improving the conductivity.

In the method for forming a diffusion prevention layer described in (^) above, the copper oxide layer on the surface of the high-purity copper layer is heated at a temperature of 100°C to 400°C for 1 hour in a normal pressure treatment atmosphere with an oxygen concentration of 10% or more, for example. It can be formed by heat treatment for about 120 hours. In addition, a copper oxide layer can be formed by CvD, or chemically oxidized using a blackening agent,
A copper oxide layer can also be formed by applying a paste-like paint containing copper oxide.

In addition, when forming a copper oxide layer by oxidation, the copper oxide layer tends to peel off when taking it out of the heat treatment furnace due to the difference in thermal contraction between copper and copper oxide, so heat treatment must be performed in advance. It is preferable to carry out the oxidation treatment in this state by accommodating the structure in a tubular body such as a stainless steel tube or by providing a protective coating on the outer surface of the structure with a glass sleeve or the like. If the oxide layer peels off, the oxygen supply source will be cut off during the subsequent heat treatment, causing variations in the formation of the diffusion prevention layer. By maintaining this state and performing heat treatment after the treatment, even if the thin oxide layer peels off to some extent, the effect of the present invention is sufficiently maintained because the oxide that serves as an oxygen supply source is present in the system. Able to demonstrate Furthermore, when using a tubular body such as a stainless steel pipe, a sufficient copper oxide layer can be formed by oxidizing the pipe while circulating air or a mixed gas of oxygen gas and inert gas. can.

In addition, in the method for forming a diffusion prevention layer described in (^) above, the copper oxide layer inside the high-purity copper layer is formed by using a tubular body as a copper member constituting the high-purity copper layer, and It can be formed by forming a copper oxide layer by performing the same treatment as the formation of a copper oxide layer on the outer surface, or by filling the tubular body with copper oxide and then integrating it.

This integration of the high-purity copper layer and the copper oxide may be performed simultaneously with the integration of the reinforced copper alloy layer and the high-purity copper layer in the copper-based member of the present invention, or may be performed in advance. good.

In the method (A) above, for a structure in which the reinforced copper alloy layer and the high-purity copper layer are integrated and has a copper oxide layer on or inside the high-purity copper layer, IX
Under a high vacuum of about 10-' Torr to 5X 10-' Torr or in an inert gas atmosphere, heat treatment is performed for about 3 to 100 hours at a temperature at which the added elements in the reinforced copper alloy are oxidized to form a diffusion prevention layer. do. If the oxide layer formed on or inside the high-purity copper layer is too small, the formation of the diffusion prevention layer will be insufficient, and if it is too large, too much oxygen will enter the high-purity copper layer, causing the diffusion prevention layer to become insufficient. As the thickness increases, the volume of the high-purity copper layer decreases due to oxidation, causing a decrease in conductivity. Therefore, it is desirable to set the amount of the copper oxide layer while taking these balances into consideration.

Additionally, depending on the type of reinforced copper alloy used during the heat treatment for forming the diffusion prevention layer, it may soften significantly when high temperatures (for example, around 500°C) are applied, resulting in a decrease in strength and the effect of the strength reinforcing layer. Put it away.

For example, taking a 1.3vt%5n-0,1wt%P-Cu alloy as an example, it has a Vickers hardness of Hv-17 at room temperature.
The Hv of about 0 drops to about Hv-80 at 700°C, resulting in significant softening and reduced strength. Therefore, in the present invention, the decrease in strength is prevented, for example, by the following method.

(a) Heat treatment is performed at a temperature at which the strength of the reinforced copper alloy does not decrease significantly, for example, at a temperature of 600° C. or lower.

(b) Heat treatment is performed at a temperature at which a diffusion prevention layer can be formed in a short period of time, for example, at a temperature of about 600°C to 700°C, and then the strengthened copper alloy whose strength has been reduced by the heat treatment is subjected to cold working, such as reduction. Surface processing causes work hardening and restores strength.

When maintaining the strength without performing surface reduction processing after the heat treatment in (a) above, 0.8vt%0r-0,2wt%Zr-
Cu.

10~30wt% old-Cu, 0.05~0.2w
It is preferable to use a strengthened copper alloy such as t%Zr-Cu, since the strength decreases little due to heat treatment.

In addition, the above method (b) of restoring strength by work hardening can be applied to all strengthened copper alloys, but if this method is used to ensure high strength and high conductivity, Appropriate conditions vary depending on the reinforced copper alloy to be used and the type of oxide to be formed, so set the processing conditions according to the material used. In addition, the strength recovered by work hardening is
Since the warp processing rate is determined by the processing rate, set the processing rate depending on the strength to be obtained and the material used, for example, 20
% to about 40%. Note that this cold working causes work hardening in the high-purity copper layer, which is expected to reduce the electrical conductivity. Therefore, the temperature at which the reinforced copper alloy does not soften after cold working,
For example, it is preferable to perform annealing at a temperature of about 200°C to 300°C.

In the above method (B) for forming a diffusion prevention layer, a structure in which a high-purity copper layer and a reinforced copper alloy layer are integrated is provided with an oxygen partial pressure lower than that of the atmosphere and oxidized on the surface or inside of the copper layer. Under a partial pressure of oxygen that can form substances, for example, the atmosphere LX 1
O-ITorr ~ LX By performing heat treatment for about 3 to 100 hours in an atmosphere with a reduced pressure of about 1O-3 Torr, a copper oxide layer is formed on the surface or inside the high-purity copper layer, and this copper oxide layer is removed. Oxygen is diffused into the high purity copper layer to form a diffusion prevention layer.

Furthermore, in the method for forming a diffusion prevention layer in (C) above, a structure in which an oxygen-containing high-purity copper layer and a reinforced copper alloy layer are integrated is subjected to metal oxidation under the same conditions as in (^) above. A diffusion prevention layer is formed by heat treatment to form a material. As the oxygen-containing copper in this case, it is preferable to use one containing about 0.05% to 1% by weight of oxygen based on pure copper (including unavoidable impurities). If the oxygen content is too low, the formation of the diffusion prevention layer will be insufficient, whereas if it is too high, the amount of oxygen remaining after heat treatment will increase, which will have a negative effect on the electrical conductivity.

Also in the above heat treatments (B) and (C), the above (^
), the strength reduction of the strengthened copper alloy can be prevented by adjusting the temperature setting for heat treatment ((a) above), or cold working is performed after heat treatment to restore the strength ((b) above).
.

Further, the diffusion prevention layer in the present invention does not necessarily have to be formed continuously at the interface of the structure in which the reinforced copper alloy layer and the high-purity copper layer are integrated, but may be formed discontinuously. good. By forming the diffusion prevention layer discontinuously in this way, even when a reinforced copper alloy layer is formed outside the high-purity copper layer, the difference between the high-purity copper layer and the reinforced copper alloy layer can be reduced. It becomes possible to maintain good heat conduction, and for example, it is possible to ensure heat dissipation when a large current is passed through a high-purity copper layer.

In order to form the diffusion prevention layer discontinuously in this way, in any of the above methods (A) to (C), at least one interface side of the member forming the high-purity copper layer or the reinforced copper alloy layer is required. By applying the heat treatment of the present invention to such a structure, metal is selectively applied to the interface portion closer to the oxide layer due to the difference in distance between the interface and the copper oxide layer. It becomes possible to precipitate oxides.

This results in a discontinuous anti-diffusion layer.

(Function) In the present invention, oxygen in the copper oxide layer formed on or inside the high-purity copper layer is diffused into the high-purity copper layer by heat treatment, and becomes solid in the high-purity copper layer. Dissolved impurities or additives that have diffused from the reinforced copper alloy layer are oxidized and precipitated, further increasing the electrical resistance of the high-purity copper layer and at the interface between the high-purity copper layer and the reinforced copper alloy layer. A diffusion prevention layer made of strong metal oxide is formed. and,
This diffusion prevention layer can prevent the added elements in the reinforced copper alloy layer from diffusing into the high-purity copper layer during this heat treatment or when heat is applied to the copper-based member after this. It becomes possible to maintain the electrical conductivity of the copper layer. Further, the strength of the reinforced copper alloy can be easily maintained by, for example, performing cold working after heat treatment and recovering the strength by work hardening.

(Example) Next, an example of the present invention will be described with reference to the drawings.

Example 1 FIG. 1 is a sectional view showing a schematic structure of an example of a wire rod to which the copper-based member of the present invention is applied.

This copper-based wire 1 is made of 0.8vt%Cr-0.2wt%Z
A high-purity copper layer 4 is formed on the outer periphery of a reinforced copper alloy layer 2 made of an r-Cu alloy with a diffusion prevention layer 3 made of oxides of Cr and Zr interposed therebetween.

The copper-based wire rod having the above structure was formed by the manufacturing method shown below.

First, the outer diameter is 10.5 mm, the inner diameter is 8 Amtp, and the length is 100 mm.
A cylindrical member 4 made of pure copper with a purity of 99.99% and a diameter of 7.9 mm is prepared inside the cylindrical member 4 made of pure copper.
11m, length 800++v 0.8wt%Cr-0,2
A cylindrical member 2 made of wt% Zr-Cu alloy is inserted and integrated by a swaging machine to an outer diameter of 1 cm.
A wire rod was produced.

Next, this integrated wire is heated to 250°C in the atmosphere.
Heat treatment was performed for 48 hours to form a copper oxide layer with a thickness of 2.8 μI on the outer surface of the high-purity copper layer 4.

Thereafter, heat treatment is performed at 590° C. for 95 hours in a vacuum with the atmosphere reduced to IX 10' Torr, and through this heat treatment, the oxygen that has diffused in the high-purity copper layer 4 and the high-purity copper alloy layer 2 are removed. A diffusion prevention layer 3 made of oxides of Cr and Zr is formed by reacting C' and Zr diffused toward the pure copper layer 4 side, and prevents Cr and 2' from diffusing into the high purity copper layer 4. At the same time, impurities that inevitably exist in the high-purity copper layer 4 were precipitated as oxides to obtain the intended copper-based wire.

I, which is the standard for the stability of the copper-based wire obtained in this way
When AC3 ratio % and specific resistance ρ at 20°C were determined as i91, lAC3 ratio %-99%, p -1,78X 10
-'Ω''el, which was a good value. Also, the tensile strength was as high as 55 kg/if, confirming that it was a copper-based wire material that satisfied both high electrical conductivity and mechanical strength.

On the other hand, for the wire material produced in Example 1, which was simply an integration of the high-purity copper layer before heat treatment and the reinforced copper alloy layer, 3X10=
Annealing was performed in a Torr vacuum at 590°C for 95 hours to produce a copper wire rod (comparative example 1) with the same dimensions as in Example 1, and the above properties were measured. As a result, the tensile strength was 50 kg/
1i, IAC9 ratio%-60%, ρ-2,87X
Only a value of to-'Ω·elm was obtained, and a clear difference in electrical resistance values was observed.

Example 2 LX
Heat treatment is performed in a vacuum of Q' Torr at 590° C. for 80 hours to form a copper oxide layer on the surface of the high-purity copper layer 4 while forming a bond between the reinforced copper alloy layer 2 and the high-purity copper layer 4. A diffusion prevention layer 3 made of oxides of C" and 2" was formed on the interface to obtain a copper-based wire.

The characteristics of this copper-based wire material were also measured in the same manner as in Example 1, and the results were as follows: IAC9 ratio %-98%, ρ-1,76
X 10-'Ω"Crys tensile strength and 53 kg/ij, respectively, showed good values.

Example 3 A wire having a copper acid or compound layer on the surface prepared in the same manner as in Example 1 above was heated for 50 minutes in an argon gas atmosphere at normal pressure.
A copper wire was obtained by heat treatment at 90° C. for 80 hours.

The characteristics of this copper-based wire material were also measured in the same manner as in Example 1, and the results were as follows: l AC3 ratio%-98%, ρ-1,76
X 10-'Ω'' cm and tensile strength of 54 kg/+j, each showing good values.

Example 4 First, as shown in FIG. 2(a), 20% oxygen was placed inside a high purity copper tube 11 made of oxygen-free high purity copper with an outer diameter of 7.911%, an inner diameter of 3.211%, and a length of 100 mm. A heat treatment is performed at 220° C. for 70 hours in an argon gas atmosphere while flowing argon gas at a rate of about 0.1 to 1 β/min to form a copper oxide with a thickness of 10 to 20 μη on the inner surface of the high purity copper tube 11. Layer 12 was formed.

Next, as shown in the same figure (b), this high-purity copper tube 11 has an outer diameter of 10.3 mm and an inner diameter of 8.111111% and a length of 100 mm.
olIIll 0.8vt%Cr-0.2wt%Zr-
The wire rod was inserted into a reinforced copper alloy tube 13 made of a Cu alloy, and was drawn and integrated to produce a wire rod having an outer diameter of 1 mm and having a copper oxide layer 12 inside a high-purity copper layer 11.

Thereafter, as in Example 1, heat treatment was performed in a high vacuum of 3X 10' Torr at 590° C. for 80 hours to form a high-purity copper layer 11 and a reinforced copper alloy layer 13, as shown in FIG. A diffusion prevention layer 14 made of Cr and 2'' metal oxide was formed at the interface with the metal oxide, and the intended copper-based wire 15 was produced.

The characteristics of this copper-based wire material were also measured in the same manner as in Example 1, and the results were as follows: 1^C8 ratio 99%, ρ-1,74X
It showed good values of 10-'Ω' elm and tensile strength of 54 kg/md.

The same effect as in Example 1 can also be obtained by forming the copper oxide layer 12 in advance in the high-purity copper layer 11 in this way and then performing heat treatment. Moreover, by using the reinforced copper alloy layer as the outer peripheral layer as in this example, a copper-based wire rod having excellent corrosion resistance can be obtained.

Example 5 In Example 4 above, instead of forming a copper oxide layer on the inner surface of the high-purity copper tube 11 made of oxygen-free high-purity copper, copper oxide powder is filled, and in this state a reinforced copper alloy tube is formed. 13, and then integrated to produce a wire rod of the same size.

Next, heat treatment was performed under the same conditions as in Example 4 to obtain a copper-based wire 15.

The characteristics of this copper-based wire material were also measured in the same manner as in Example 1, and the results were as follows: lAC3 ratio%-98%, ρ-1,74X
IO'Ω''ells tensile strength was 53.5 kg/-, which was a good value.

By arranging copper oxide in the high-purity copper layer 11 in advance in this manner, the effects of forming the diffusion prevention layer 14 and further purifying the high-purity copper layer 11 can be obtained as in the first embodiment.

Example 6 First, the outer diameter was 10 Jig and the inner diameter was 8. La5s length 100
Inside a reinforced copper alloy tube made of 0mm 0.8vL%Cr-0.2vt%Zr-Cu alloy, an outer diameter of 7.9cm and a length of 1o.
A high-purity copper rod containing 0.3% by weight of ooav oxygen was inserted, and a wire rod with an outer diameter of 1 ms was produced by drawing and integrating the rod.

Thereafter, heat treatment is performed in a high vacuum of 3X 10-' Torr at 590°C for 80 hours to diffuse oxygen contained in the high-purity copper rod toward the interface with the reinforced copper alloy layer, thereby converting Cr and A diffusion prevention layer made of a metal oxide of 2" was formed, and impurities in the high-purity copper layer were precipitated to produce the intended copper-based wire.

The characteristics of this copper-based wire material were also measured in the same manner as in Example 1, and the results were as follows: lAC3 ratio%-98%, ρ-1,74X
It showed good values of 10-'Ω・0 and tensile strength of 54 kg/ij. As in this embodiment, a diffusion prevention layer made of a metal oxide can also be formed by using high purity copper containing oxygen as the high purity copper layer.

Example 7 As shown in FIG. 3(a), in the same manner as in Example 4, except that a high purity copper tube 21 having an uneven shape on the outer surface was used as a steel tube made of oxygen-free high purity copper, A wire rod 24 having the same dimensions was produced in which the high-purity copper layer 21 and the reinforced copper alloy layer 23 were integrated and had a copper oxide layer 22 inside the high-purity copper layer 21. Note that the interface shape between the high purity copper layer and the reinforced copper alloy layer 23 in this wire 24 had an uneven shape according to the shape of the high purity copper tube 21.

Next, this wire 24 was heat-treated under the same conditions as in Example 4 to form a diffusion prevention layer 25 at the interface as shown in FIG. 3(b), thereby obtaining the intended copper-based wire 26.

When the copper-based wire material 26 thus obtained was cut in the radial direction and the shape of the diffusion prevention layer 25 was confirmed, it was found that the copper formed in the high-purity copper layer 21 was oxidized as shown in FIG. 3(b). layer 2
2 and each interface position, the diffusion prevention layer 2
5 was formed discontinuously.

By forming the diffusion prevention layer 25 discontinuously in this manner, it is possible to prevent heat conduction from the high purity copper layer 21 to the reinforced copper alloy layer 23 from being inhibited.

In addition, when the characteristics of this copper-based wire material were measured in the same manner as in Example 1, it was found that IAC8 ratio %-99%, ρ-1
．． 74 x 10-'Ω・C■, tensile strength 55kg/m
j showed good values.

Example 8 First, outer diameter 10.511% inner diameter 8.1 m1% length 100
A high-purity copper rod containing O4wt% of oxygen with an outer diameter of 7.9cm and a length of loooIlm is inserted into a reinforced copper alloy tube of 0mm and made of a 0.lvt% Zr-Cu alloy, and the rod is swaged together by a swaging machine. A wire rod with an outer diameter of 5 cm was produced.

Then, in an argon gas atmosphere at 700°C for 1
Heat treatment is performed under the conditions of 2 hours to diffuse oxygen contained in the high-purity copper rod toward the interface with the reinforced copper alloy layer to form a diffusion prevention layer made of metal oxide. By precipitating the impurities inside, the high conductivity of high-purity steel was ensured.

The hardness of the heat-treated wire rod was extremely reduced by the heat treatment at 700°C, so after the heat treatment, the wire rod was subjected to area reduction processing by cold working to a diameter of 4 mm to cause work hardening.

Thereafter, annealing was performed in an argon gas atmosphere at 220° C. for 60 minutes to produce the desired copper-based wire.

Regarding this copper-based wire, various characteristics were measured in the same manner as in Example 1, and the results were as follows: IAC8 ratio%-98%, ρ-1,
It showed good values of 74X to'Ω"el and tensile strength of 51 kg/-. The tensile strength of the copper wire immediately after heat treatment was 20 kg/-.

As in this example, the temperature is 700°C, where oxygen diffusion becomes active.
By heat treating at a certain temperature and then restoring the strength by surface reduction processing, it is possible to significantly shorten the heat treatment time and maintain the strength sufficiently. In order to ensure both high strength and high conductivity through cold working, the conditions differ depending on the strengthened copper alloy used and the type of oxide formed, so the heat treatment conditions and processing conditions are determined depending on the type of strengthened copper alloy. need to be set.

[Effects of the Invention] As explained above, according to the present invention, a copper-based member can be obtained in which the high electrical conductivity of high-purity copper and the mechanical strength of a reinforced copper alloy are integrated without impairing each other.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view showing a copper-based wire manufactured according to one embodiment of the present invention, and FIGS. 2 and 3 are diagrams showing manufacturing steps in other embodiments of the present invention, respectively. 1.15.26... Copper wire material, 2.13.23
......Reinforced copper alloy layer, 3.14.25...
- Diffusion prevention layer, 4.11.22...High purity copper layer. Applicant Toshiba Corporation Patent Attorney Sasa Suyama - Figure 1 (a) (C) Figure 2 (b) Figure 3

Claims (7)

[Claims] (1) A strengthened copper alloy layer made of an element or compound that is easily oxidized, a high purity copper layer with excellent electrical conductivity, and the strengthened copper alloy layer interposed between the strengthened copper alloy layer and the high purity copper layer. A copper-based member comprising a diffusion prevention layer made of a metal oxide of an additive element. (2) The copper-based member according to claim 1, wherein the diffusion prevention layer is formed discontinuously. (3) In manufacturing a copper-based member formed by integrating a reinforced copper alloy layer made of an element or compound that is easily oxidized and a high-purity copper layer with excellent electrical conductivity, the reinforced copper alloy layer and the high-purity copper layer are manufactured. After forming an oxide layer on the surface or inside of the high-purity copper layer of the structure integrated with the above-mentioned high-purity copper layer, Heat treatment is performed under an oxygen partial pressure that can form oxides on the surface or inside, and a diffusion prevention layer made of a metal oxide of an element added to the strengthened copper alloy layer is formed between the strengthened copper alloy layer and the high-purity copper layer. A method for manufacturing a copper-based member, characterized by forming a copper-based member. (4) The method for manufacturing a copper-based member according to claim 3, characterized in that the copper-based member on which the diffusion prevention layer is formed is subjected to cold working. (5) Claim 3 characterized in that the interface of the structure in which the reinforced copper alloy layer and the high-purity copper layer are integrated has an uneven shape.
The method for manufacturing the copper-based member described above. (6) When manufacturing a copper-based member formed by integrating a reinforced copper alloy layer made of an element or compound that is easily oxidized and a high-purity copper layer with excellent electrical conductivity, the high-purity copper layer is replaced with an oxygen-containing high-purity A structure made of copper and in which the strengthened copper alloy layer and the high-purity copper layer are integrated is subjected to heat treatment in a vacuum or in a non-oxidizing atmosphere, so that the strengthened copper alloy layer and the high-purity copper layer are integrated. A method for producing a copper-based member, characterized in that a diffusion prevention layer made of a metal oxide of an additive element of the reinforced copper alloy layer is formed between the layers. (7) The method for manufacturing a copper-based member according to claim 6, characterized in that the copper-based member on which the diffusion prevention layer is formed is subjected to cold working.