JPH02213433A - Dispersion strengthened copper alloy and its manufacture - Google Patents

Abstract

PURPOSE:To easily manufacture the dispersion strengthened copper alloy having high electric conductivity and high strength by pulverizing and mixing copper oxide with dispersion grain raw material hard to reduce, selectively reducing copper oxide at a specified temp. and thereafter subjecting the mixed powder to compacting and sintering. CONSTITUTION:Copper oxide and dispersion grain raw material chemically stabler than copper oxide in a reducing atmosphere such as Al2O3 are mechanically pulverized and mixed. While the obtd. mixed powder is held to <=1065 deg.C, copper oxide therein is selectively reduced. The selectively reduced mixed powder is compacted. The compact is sintered to obtain a sintered body contg. a copper mother phase and dispersion grains. In the copper mother phase of the sintered body, the structure contg. 0.5 to 6vol.% dispersion grains and having <=0.3mum average diameter of mother phase area free from the dispersion grains is formed. Furthermore, the total quantity of the elements to enter a solid soln. such as Al contained in the copper mother phase is regulated so that the degree of the electric conductivity to be reduced at the time of adding the quantity to pure copper amounts to <=5% IACS. In this way, the dispersion strengthened copper alloy combining high electric conductivity and high strength can easily be obtd. with good reproducibility.

Description

Detailed Description of the Invention [Object of the Invention] (Industrial Application Field) The present invention relates to a dispersion-strengthened copper alloy in which dispersed particles are formed in a copper matrix and a method for producing the same, and Concerning various applications of reinforced copper alloys.

(Conventional technology) In recent years, there has been an increasing demand for copper alloys that have both high electrical conductivity and high mechanical strength for applications such as coil materials for generating high magnetic fields, lead frames for semiconductors, and electrodes for spot welding. ing. However, electrical conductivity and strength in copper alloys are contradictory properties, and it is difficult to achieve both.

By the way, as a copper alloy that can achieve both electrical conductivity and strength to some extent, a dispersion-strengthened copper alloy is known, which is made by dispersing dispersed particles in a copper matrix. In dispersion-strengthened copper alloys, the two contradictory properties described above can be achieved by uniformly dispersing very fine dispersed particles in the copper matrix.

As a method for producing dispersion-strengthened alloys, a technique is known in which matrix powder and dispersed particles are crushed and mixed using a mixer such as a ball mill. However, in the case of dispersion-strengthened copper alloys, In this way.

Therefore, it is extremely difficult to disperse the dispersed particles finely and uniformly. Therefore, the obtained copper alloy ends up having low strength.

On the other hand, an internal oxidation method has been proposed as another method for manufacturing dispersion-strengthened copper alloys. This method heats the powder or chips of an alloy made of sea bream and an element that is more easily oxidized than copper in an oxidizing atmosphere to oxidize the surface, and then seals it in a sealed container and heats it. In this method, oxygen is diffused into the inside of the alloy powder to obtain powder or chips in which oxide particles of the additive element of the alloy powder are dispersed. According to this method, it is possible to obtain a dispersion-strengthened copper alloy in which fine dispersed particles are uniformly dispersed in the copper matrix.

However, the internal oxidation process in which oxygen on the surface of the alloy powder is diffused into the interior to completely oxidize the added elements requires a very long time, so some added elements are not oxidized and remain as solid solution elements. It tends to remain in the copper matrix. If the added element remains as a solid solution element in the copper matrix, it will disperse and
A problem arises in that the electrical conductivity of the reinforced copper alloy is significantly reduced.

Furthermore, if an attempt is made to improve the electrical conductivity by reducing the amount of dispersed particles, the strength will decrease.

A mixed oxide reduction method is known as yet another method for producing dispersion-strengthened copper alloys. This method uses Trans, AI
ME, Vol. 218, (1980) 775 pages 1 Edited by the Powder Metallurgy Technology Association, Powder Metallurgy Technology Course 9゜ Powder Metallurgy Application Products (IV) - Special Materials - (19 [F4]) 6 pages (
As disclosed in Nikkan Kogyo Shimbun (published by Nikkan Kogyo Shimbun) and Japanese Patent Application Laid-Open No. 62-93321, etc., the oxide of the metal that will become the matrix and the dispersed particles are mixed and crushed, and the metal that will be the matrix of the mixture is In this method, a mixture of a metal and dispersed particles is prepared by reducing only the oxide of the metal, and then the mixture is sintered by a conventional powder metallurgy method to produce a dispersion-strengthened alloy.

However, although good results have been obtained when the mixed oxide reduction method is applied to the production of dispersion-strengthened alloys with nickel or silver as the matrix, oxidized steel is used as the oxide of the matrix metal. When applied to the production of dispersion-strengthened copper alloys, it is difficult to uniformly disperse fine dispersed particles in the matrix. Therefore, with this method, a high-strength dispersion-strengthened copper alloy cannot be obtained.

(Problems to be Solved by the Invention) The present invention has been made to solve the above-mentioned problems, and its purpose is to create a dispersion-strengthened copper alloy that has both high electrical conductivity and high strength. The object of the present invention is to provide a method for producing a dispersion-strengthened copper alloy, which can produce such a dispersion-strengthened copper alloy in a simple process.

[Structure of the Invention] (Means and Effects for Solving the Problems) The dispersion-strengthened copper alloy of the present invention comprises a copper matrix and a dispersion contained in the copper matrix in an amount of 0.5 to 6% by volume. particles, and the average diameter of the matrix region where no dispersed particles are present is 0.3 μm or less, and the total amount of solid solution elements contained in the copper matrix is when that amount is added to pure copper. The decrease in electrical conductivity is 5% IACS
It is characterized in that the amount is as follows.

Examples of the dispersed particles include aluminum oxide, zirconium oxide, titanium oxide, silicon oxide, magnesium oxide, yttrium oxide, chromium oxide, aluminum nitride, silicon nitride, titanium nitride, boron nitride, titanium carbide, boron carbide, titanium boride, etc. They may be used alone or in a mixture of two or more.

It is well known that solid solution elements in the copper matrix significantly reduce electrical conductivity. Therefore, the total amount of solid solution elements in the copper matrix needs to be such that the amount of decrease in electrical conductivity is within an acceptable range. In other words, if the electrical conductivity decreases by more than 5% IACS only due to solid solution elements in the matrix, the presence of dispersed particles will further reduce the electrical conductivity, resulting in insufficient electrical conductivity of the dispersion-strengthened copper alloy. Therefore, the total amount of solid solution elements in the copper matrix is defined as described above.

The effect of lowering electrical conductivity varies depending on the type of solid solution element, and it is known that the relationship between the amount of each element in solid solution and electrical resistivity is as shown in Figure 1 (Source F , P
avlek and K, Re1chel: p amount)
The result is as shown in Table 1.

Among the dispersed particles, aluminum oxide is particularly preferred, and when aluminum oxide is used as the dispersed particles, it is desirable that the amount of aluminum dissolved in the copper matrix is 0.04% by weight or less.

As mentioned above, when the amount of aluminum dissolved in the copper matrix exceeds 0.04i1ft%, the electrical conductivity of the matrix decreases to a range exceeding 5% IACS, and the dispersion-strengthened copper alloy This is because it significantly reduces the electrical conductivity of.

The reason for specifying the content of the dispersed particles in the copper matrix in the above range is that if the amount is less than 0.5% by volume, the 0.296 iJ force in the dispersion-strengthened copper alloy will be 40 kg/a.
m2 or more, and if it exceeds 6% by volume, not only will it be impossible to make the electrical conductivity of the dispersion-strengthened copper alloy 85% IACS or more, but also secondary processing will become difficult.

It is necessary that the dispersed particles in the alloy of the present invention are distributed such that the average diameter of the copperware phase region where there are no dispersed particles is 0.3 μm or less. This is because if the average diameter exceeds 0.3 μm, the tensile strength and 0.2% proof stress will decrease significantly. The average diameter of the copperware phase region was determined as follows. That is, a thin film sample was prepared from a dispersion-strengthened copper alloy sample, and a photograph of this thin film sample was taken at a magnification of 100,000 times using a transmission electron microscope. 10
Select a point, draw the 10 largest circles that can be drawn including each point without including the dispersed particles (each point is not necessarily at the center of this circle), and calculate the average diameter of these circles as the dispersed particle. is the average diameter of the copperware facies region where it does not exist.

Next, a method for producing a dispersion-strengthened copper alloy of the present invention will be explained.

First, copper oxide, which is a copper raw material for the parent phase, and dispersed particles, which are chemically more stable than copper oxide, are prepared in a reducing atmosphere. As copper oxide, cuprous oxide (CuzO), cupric oxide (Cub)
, and non-stoichiometric copper oxide (CuO,x). From the viewpoint of uniformly dispersing the dispersed particles, copper oxide has a thickness of 5 μm.
Hereinafter, it is more preferable to use particles with a particle size of 1 μm or less.

Any dispersed particles may be used as long as they are chemically more stable than copper oxide in a reducing atmosphere. Such dispersed particles include aluminum oxide, zirconium oxide, titanium oxide, silicon oxide, magnesium oxide, yttrium oxide, chromium oxide, aluminum nitride, silicon nitride, titanium nitride, boron nitride, titanium carbide, boron carbide, Mention may be made of IFI selected from titanium boride or a mixture of 28 or more. Further, from the viewpoint of uniformly dispersing the particle size of the dispersed particle raw material in the copper matrix, it is desirable that the particle size is 1 μm or less, more preferably 0.05 μm or less. When aluminum oxide is used as the dispersed particles, those having a γ crystal type or amorphous are preferable.

Next, the copper oxide as the raw material for the copper matrix and the dispersed particle raw material are mixed so that the dispersed particles are 0.5% of the copper matrix after reduction of the copper oxide.
After blending so that the content is 6% by volume, it is mechanically crushed and mixed. In this case, copper oxide powder as a raw material is brittle and is easily crushed. Therefore, the particle size of the prepared mixed powder is 0.05 μm or less, and the average particle size is also 0.
．． The particles are as fine as 01 to 0.02 μm.

The pulverization and Φ mixing of the raw materials can be carried out using a known mixing device such as a ball mill or an attriter.

In this case, it is desirable that the container and the ball be made of non-metal. This is because if pulverization and mixing are performed using a metal container or ball, metals such as iron may be mixed into the mixture, which may significantly reduce the electrical conductivity of the resulting dispersion-strengthened copper alloy. Because there is.

Next, the mixed powder is charged into a reducing furnace maintained under a reducing atmosphere to selectively reduce the copper oxide in the mixed powder. This converts copper oxide to metallic copper. This reduction step can employ either gas reduction or reduction using a solid reducing agent.

In the case of reduction using gas, heat treatment is performed in a reducing gas atmosphere such as hydrogen gas. When using a solid reducing agent,
When the copper oxide and the dispersed particle raw material are mixed, a solid reducing agent such as carbon is also added and mixed, and the mixture is reduced by heat treatment in a reducing atmosphere or an inert atmosphere. however,
When using a solid reducing agent, there is an optimum value for the amount added; if the amount is less than this, oxygen will remain and the conductivity of the final alloy will decrease; There is a risk that an excessive amount of the solid reducing agent may remain and impair workability during secondary processing such as rolling.

Note that this reduction step is carried out in an atmosphere having a reducing potential that can reduce the copper oxide in the mixed powder to a metallic copper state and prevent the dispersed particles from being reduced to a metallic state. However, it is not necessary to create an atmosphere having a reducing potential in which the dispersed particles are not completely reduced. For example, when the dispersed particles are made of T i O2, T
If it stops in the iO state, there is no problem.

Furthermore, in the reduction step, all parts of the mixed powder must be maintained at a temperature that does not exceed 1065° C., which is the eutectic temperature of copper and copper oxide, until the reduction of copper oxide is completed. This is because if even a portion of the mixed powder exceeds 1065°C, the average diameter of the copper matrix region where no dispersed particles exist exceeds 0.3 μm, resulting in a non-uniform structure and a significant decrease in strength. .

Various methods can be used to maintain the mixed powder at a temperature not exceeding 1065°C. For example, the reduction reaction of copper oxide with hydrogen involves the generation of a large amount of heat, so the heating temperature of the reduction furnace must be kept low, and the partial pressure and flow rate of the reducing gas must be adjusted to ensure that other gases are mixed in with the reducing gas as necessary. The partial pressure and flow rate of the gas are controlled to keep the amount of heat generated per unit time in the reduction reaction low, and the reduction is carried out while maintaining the mixed powder at a temperature not exceeding 1065°C. When the reduction of copper oxide is almost completed, a large amount of heat is no longer generated by the reduction of copper oxide, so even if the heating temperature of the reduction furnace is increased to a certain extent, if the temperature is below 1065°C, the temperature of the mixed powder will be lower. does not exceed 1065°C.

After the above-mentioned reduction process, the mixed powder is molded by an appropriate method to produce a molded body, and this molded body is fired and sintered in a reducing or inert atmosphere, thereby reducing the copper matrix. A dispersion-strengthened copper alloy in which dispersed particles are dispersed is manufactured. A dispersion-strengthened copper alloy may be manufactured by simultaneously performing molding and sintering of this mixed powder using a hot pressing method. In addition, the mixed metal powder before reduction is placed in a mold and hot pressed in an atmosphere that can selectively reduce only the copper oxide.
A dispersion-strengthened copper alloy may be manufactured by performing molding and sintering simultaneously.

The dispersion-strengthened copper alloy produced through the above steps can be used as is, or may be used after performing secondary processing if necessary. The dispersion-strengthened copper alloy of the present invention also has excellent secondary workability.

According to the present invention, the 0.2% yield strength at room temperature is 40 kg.
/am' or more, it is possible to obtain a dispersion-strengthened copper alloy having an electric conductivity of 85% IACS and having both high strength and high conductivity. In particular, aluminum oxide is used as the dispersed particles, and the amount of aluminum solid solution in the copper matrix is reduced to 0.
．． By setting the content to 04ffiffi% or less, a dispersion-strengthened copper alloy with good strength and electrical conductivity can be obtained.

Furthermore, according to the method for manufacturing a dispersion-strengthened copper alloy according to the present invention, copper and copper oxide produced in the reduction process are prevented from becoming eutectic and melting, thereby avoiding agglomeration and coarsening of dispersed particles. As a result, the average diameter of the copperware phase region where no dispersed particles are present can be 0.3 μm or less. As a result, a dispersion-strengthened copper alloy having a structure in which dispersed particles are uniformly dispersed in a copper matrix and having the above-mentioned excellent properties can be easily produced with good reproducibility. In addition, the particle size of the dispersed particles of the dispersion-strengthened copper alloy produced in this way is 0.005
~0.05 μm.

The dispersion-strengthened copper alloy according to the present invention can be applied to various uses. First, a high magnetic field generating coil made of a dispersion-strengthened copper alloy according to the present invention will be explained.

In recent years, there has been an increasing demand for high magnetic field generation for MHI, nuclear fusion, magnetic levitation railways, physical property JlJ determination, etc. In order to generate such a high magnetic field, superconducting coils that consume no power are widely used. However, with superconducting coils, it is impossible to generate a high magnetic field that exceeds the critical magnetic field. Therefore, in order to generate a high magnetic field that exceeds the limits of superconducting coils, a coil made of a normal conductor must be used for at least a portion of the magnetic field generating coil. It is necessary to use a material constituting such a normally conducting coil that has high electrical conductivity, high thermal conductivity, and high strength.

In other words, in order to generate a high magnetic field, it is necessary to pass a large current through the coil, and since a normal conducting coil generates a large amount of heat due to Joule heating, it is necessary to minimize the generation of heat and further reduce the amount of heat generated. The coil material is required to have high electrical conductivity and high thermal conductivity so that the generated heat can be quickly dissipated into a coolant such as cooling water. Furthermore, since a huge electromagnetic force acts on a coil through which a large current flows, the coil must also have high strength to withstand this electromagnetic force.

The dispersion-strengthened copper alloy according to the present invention has both high electrical conductivity and high strength as described above, and also inherently has high thermal conductivity. The formed high magnetic field generating coil has extremely excellent characteristics.

The high magnetic field generating coil according to the present invention can be produced by using the dispersion-strengthened copper alloy manufactured by the method described above as it is, or by performing secondary processing as necessary and further heat treatment if necessary. Obtained by processing or machining.

The dispersion-strengthened copper alloy of the present invention that constitutes this coil has high elongation and is strong against impact, so the coil of the present invention can be used not only as a steady magnet using a steady current, but also as a pulse war magnet using a pulsed current. It can be used as a coil for quasi-pulsed magnets. Furthermore, since the coil of the present invention has both high strength and high electrical conductivity even at high temperatures above room temperature, it can be applied to coils used at high temperatures such as coils for molten metal electromagnetic pumps. Can be done.

Next, a resistance welding electrode made of a dispersion-strengthened copper alloy according to the present invention will be explained.

Resistance welding electrodes are required to have high thermal and electrical conductivity, high strength, and good heat resistance. For this reason, copper alloys to which small amounts of alloying elements such as tungsten, cadmium, chromium, and zirconium are added to improve strength and heat resistance have conventionally been used as materials for resistance welding electrodes. however,
In recent years, resistance welding work has become highly automated and resistance welding has come to be carried out at very high repetition rates, and the conditions of use have become even more severe. For this reason, conventional resistance welding electrodes made of copper alloys do not have a heat resistance of ten degrees, and deformation of the electrodes occurs after a short period of use. Therefore, in order to perform high-precision welding, it is necessary to perform correction work on the electrode after welding work or to frequently replace the electrode, which has been a factor that hinders productivity improvement.

The dispersion-strengthened copper alloy according to the present invention has both high electrical conductivity and high strength as described above, and also inherently has high thermal conductivity and good heat resistance. Resistance welding electrodes made of reinforced copper alloys are fully usable for high repetition rate resistance welding operations.

The resistance welding electrode according to the present invention can be made by using the dispersion-strengthened copper alloy produced by the method described above as it is, or by performing secondary processing as necessary, and further heat treatment if necessary, and then performing plastic processing. Alternatively, it can be obtained by machining.

Next, a composite superconducting wire using the dispersion-strengthened copper alloy according to the present invention will be explained.

A composite superconducting wire is formed by combining a metallic base material and a superconducting core wire. As the superconducting core wire, Nb-Ti
Alloy superconductors such as Nb.

A compound superconductor such as Sn or an oxide superconductor such as YBCO is used, and the metallic base material is Cu,
A(1, Ag, Au, Nb, Ta.

Cu-NL and Cu-8n are used. Among the materials used for the metallic base material, Ag, Cu, and Ag.

Au acts as a stabilizing material for the superconducting core wire. In such composite superconducting wires, the above-mentioned materials used as base materials have low work hardening properties and low softening temperatures when processed, so they are non-magnetic at low temperatures like stainless steel, and are relatively non-magnetic. It was necessary to use a material with high strength as a reinforcing material.

In addition, because the softening temperature of the base material is low, it is difficult to perform integrated composite processing with a relatively hard superconductor, resulting in uneven deformation of the composite material during processing, resulting in uneven cross-sectional area of the superconducting core wire. There was a fear that it would be more likely to cause wire breakage.

As a solution to these problems, it has been proposed to use a dispersion-strengthened copper alloy as a base material, which has the potential to have both high electrical conductivity and high strength (Japanese Patent Application Laid-Open No. 1986-1999).
264609, Japanese Patent Application Laid-Open No. 63-53811)
. Thereby, the base material can serve as both a reinforcing material and a stabilizing material for the composite superconducting wire. However, as mentioned above, conventional dispersion-strengthened copper alloys cannot achieve both strength and electrical conductivity, and also have a residual resistance ratio of RR.
It had the disadvantage of low R and was unsatisfactory as a base material for composite superconducting wires.

On the other hand, since the dispersion-strengthened copper alloy according to the present invention has both high electrical conductivity and high strength as described above, it can be used as a reinforcing material for composite superconducting wires by using it as a base material. Shows sufficient properties as a stabilizing material.

That is, the composite superconducting wire of the present invention is characterized by having a base material formed of the dispersion-strengthened copper alloy according to the present invention and a superconducting core wire provided in the base material. Very good characteristics can be obtained.

Such a composite superconducting wire can be produced by using the dispersion-strengthened copper alloy manufactured by the method described above, as it is, or by performing secondary processing as necessary, and further heat treatment if necessary, followed by plastic processing or mechanical processing. It can be manufactured by fabricating a base material through processing and integrating this base material and a superconducting core wire by appropriate means. At this time, the superconducting core wire is coated with a dispersion-strengthened copper alloy as a base material to form a composite superconducting wire, or the superconducting core wire is coated with a dispersion-strengthened copper alloy and then further processed to form a composite superconducting wire. Alternatively, a substance that becomes a superconductor through heat treatment is used as a superconducting core material, and the superconducting core wire is coated with a dispersion-strengthened copper alloy, which is further processed, and then heat treated to make the superconducting core wire material superconducting. The superconducting wire is converted into a composite superconducting wire. Further, the composite superconducting wire thus formed may be covered with stainless steel or the like.

Furthermore, the superconducting core wire may be coated with copper in advance, and the outside thereof may be further coated with the dispersion-strengthened copper alloy according to the present invention. Note that the composite superconducting wire of the present invention is not limited to a concentric shape in which a superconducting core wire is coated with a dispersion-strengthened copper alloy, etc., but may have a plurality of superconducting core wires, or may be arranged in a flat plate shape, for example. A dispersion-strengthened copper alloy base material may be disposed directly on the superconducting wire or via another metal matrix.

Next, a highly electrically conductive spring made of a dispersion-strengthened copper alloy according to the present invention will be explained.

Highly conductive springs are used in various electrical and electronic devices such as connectors, switches, relays, and slip rings.
It not only has high electrical conductivity, but also high thermal conductivity, high strength, good heat resistance, good plating properties, and easy bonding with electrodes. It is also required to have good sliding properties (abrasion resistance) and ballistic properties. Conventionally, such conductive spring materials and binding materials have been made of copper alloys (phosphor bronze containing 4.2 to 9% Sn and 0.03 to 0.3% P) specified in JIS Type 2 or Type 3. ) was used. However, in recent years, in the semiconductor field, there has been a remarkable trend toward higher integration and miniaturization of elements, and with this trend, smaller size and higher performance are required for conductive springs used in various electrical and electronic devices. For this reason, electrically conductive springs are required to have high electrical conductivity and high strength in the negative layer. As a material that satisfies these requirements, for example, Japanese Patent Application Laid-Open No. 14612/1983 proposes the use of beryllium-copper alloy, but this is difficult due to the toxicity of Be and the difficulty of precipitation hardening. However, its use was limited, and it also had the disadvantage of insufficient electrical conductivity.

In contrast, the dispersion-strengthened copper alloy according to the present invention has both high electrical conductivity and high strength, as described above.
Furthermore, the spring made of the dispersion-strengthened copper alloy according to the present invention has extremely excellent characteristics as a high electrical conductivity spring because it also has other properties required for high electrical conductivity springs.

This highly electrically conductive spring is also used for the magnetic field generation mentioned above. As with steel, dispersion-strengthened copper alloys can be subjected to plastic working or machining as they are, or they can be subjected to secondary processing if necessary, heat treated if necessary, and then subjected to plastic working or machining. can get.

Next, a description will be given of a hard frame made of a dispersion-strengthened copper alloy according to the present invention.

Lead frames used in semiconductor devices are required to have high thermal conductivity and electrical conductivity, high strength, good heat resistance, and good plating properties. Conventionally, such lead frames can be broadly classified into those using Fe-Ni alloys and those using copper alloys. Examples of the former include Kovar and Fe-42Ni, which have high strength and good heat resistance and plating properties. Examples of the latter include phosphor bronze, CA 194, and CA 195, which have excellent electrical conductivity and good plating properties. However, in recent years, in the semiconductor field, there has been a remarkable trend toward higher integration and miniaturization of elements, and with this, lead frames have become
High strength, high thermal conductivity, and high electrical conductivity are required for the layer, and the above-mentioned materials have not been able to meet these demands.

In contrast, the dispersion-strengthened copper alloy according to the present invention has both high electrical conductivity and high strength, as described above.
Furthermore, since it also has the characteristics required of other lead frames, the lead frame formed of the dispersion-strengthened copper alloy according to the present invention has extremely excellent characteristics.

In addition, in these applications, when a dispersion-strengthened copper alloy manufactured by the conventional internal oxidation method is used as the material, elements that should become oxides as dispersed particles do not exist even after long-term diffusion treatment. A portion of it remains unoxidized, and as a result, it exists as a solid solution element in the copper matrix, resulting in an insufficient electrical conductivity of the resulting alloy.

(Example) Examples of the present invention will be described in detail below.

First, alloy manufacturing conditions will be described for Examples 1 to 9 included within the scope of the present invention and Comparative Examples 1 to 9 that fall outside the scope of the present invention.

Examples 1-9 First, cupric oxide with a particle size of 1 μm is used as a matrix raw material.

Using powder, aluminum oxide powder (γ-type, α-type, amorphous), zirconium oxide powder, yttrium oxide powder, and silicon nitride powder as raw materials for dispersed particles were added to the powder, each converted to a ratio of 0 to copper after reduction. Nine types of mixed powders were prepared by blending in the range of .5 to 6% by volume. The types, particle sizes, and amounts of the dispersed particles are listed in Table 2 below. Subsequently, these mixed powders were dry ground and mixed for 4 days in a ball mill consisting of an aluminum oxide container and balls.

Next, the pulverized and mixed powder is placed in an alumina boat, and Pt/(Pt-Rh) thermocouples protected by heat-resistant alloy sheaths with a diameter of 0.5 fin are inserted into five locations of the mixed powder for reduction. 20 minutes in a mixed gas flow of argon and hydrogen at a total pressure of 1 atm while controlling the local temperature rise of the mixed powder inside.
Reduction was started at 0°C. At this time, the mixing ratio of argon and hydrogen in the mixed gas was set to 5:1 (volume ratio) so that the local maximum temperature of the mixed powder did not exceed 1065°C.
Reduction was carried out at a flow rate of min (value at 20° C. and 1 atm). Then, the final temperature was 900°C (50°C only in Example 1).
After reaching 900°C, the supply of argon was stopped and the temperature was maintained in a pure hydrogen flow of 3jl/min for 1 hour. After cooling, nine types of dispersion-strengthened copper alloy powders obtained by reduction were filled into a carbon mold, and heated at 900 °C in a vacuum.
A billet of dispersion-strengthened copper alloy was produced by hot press molding at a temperature of 0.degree. C. and a pressure of 400 kg/cti.

Comparative Examples 1 to 3 Cupric oxide powder with a particle size of 1 μm was used as a matrix raw material, and aluminum oxide powder with a particle size of 0.05 μm was added as a dispersed particle raw material, each converted into a ratio to copper after reduction. Three types of mixed powders were prepared by blending 1.5% by volume, 3.0% by volume, and 6.0% by volume. In the reduction process, 5f of mixed gas with a mixing ratio of argon and hydrogen of 1=3! Billets of three types of dispersion-strengthened copper alloys were manufactured in the same manner as in Example 1, except that the flow rate was 1/min. In addition, in the reduction process, the maximum temperature of the mixed powder is locally 1065°C.
exceeded.

Comparative Examples 4 to 6 Cupric oxide powder with a particle size of 1 μm was used as a matrix raw material, and aluminum oxide powder with a particle size of 0.05 μm was added as a dispersed particle raw material, each converted into a ratio to copper after reduction. Three types of mixed powders were prepared by blending 0.3% by volume, 7.5% by volume, and 10.0% by volume. Billets of three types of dispersion-strengthened copper alloys were produced from these mixed powders in the same manner as in Example 1.

Comparative Example 7 Pure copper powder with a particle size of 5 μm was used as a matrix raw material, and 3.0% by volume of aluminum oxide powder with a particle size of 0.05 μm as a dispersed particle raw material was blended therewith to produce a mixed powder. Subsequently, this mixed powder was dry mixed and pulverized for 4 days in a ball mill consisting of an aluminum oxide container and balls.

Next, the pulverized mixed powder was placed in an alumina boat, and heated at 900 °C in a mixed gas flow with a mixing ratio of argon and hydrogen of 5:1 (volume ratio) and a flow rate of 3 N/ml (value at 20 ° C. and 1 atmosphere). ℃ for 1 hour, and after cooling, it was filled into a carbon mold and heated at 900℃ in vacuum for 40 minutes.
A dispersion-strengthened copper alloy billet was produced by hot press molding at a pressure of 0 kg/cj.

The electrical conductivity at room temperature was measured for the dispersion-strengthened copper alloy billets of Examples 1 to 9 and Comparative Examples 1 to 7, and the tensile strength was measured using test pieces cut from each billet, 0 and 2% at room temperature. The yield strength and elongation were determined as δP1. In addition, the electrical conductivity is West Germany lN5TITUT D
Sigma Test (trade name) 2.0 manufactured by R, POR3TER
/i11 was determined using 67-061.

In addition, the amount of solid solution of the metal element constituting the dispersed particles in the copper matrix and the amount of solid solution of other elements were determined as n1. The n1 constant of the amount of solid solution is determined by heating and dissolving each dispersion-strengthened copper alloy sample in a mixed solution of aqueous ammonia and hydrogen peroxide, and causing the precipitation of dispersed particles that are not dissolved in this mixed solution. The precipitate was separated by filtration using two 0.05 μm filters, and the filtrate was quantitatively analyzed by spectrophotometry. After determining the solid solution ml, a copper alloy having the same components as the parent phase was prepared and its electrical conductivity was determined to #J, and the amount of decrease in the electrical conductivity of the parent phase due to the solid solution element was determined. At this time, conductivity was determined by API using the sigma test described above, and oxygen-free copper was
The amount of decrease in electrical conductivity from 102% IACS, which is the electrical conductivity of FHC, was determined.

Furthermore, as mentioned above, a thin film sample was prepared from the dispersion-strengthened copper alloy sample, and a photograph of this thin film sample was taken at a magnification of 100,000 times using a transmission electron microscope. Select any 10 points at the position of
Draw the 10 largest circles that can be drawn without including each point and not including the dispersed particles (each point is not necessarily the center of this circle)
The average value of the diameters of these circles was taken as the average diameter of the copper matrix region where no dispersed particles were present. However, Comparative Examples 1, 2゜3.
Since sample No. 7 had a coarse structure, it was measured using a photograph with a magnification of 5,000 times.

Table 2 shows the conditions of Examples 1 to 9 and Comparative Examples 1 to 7 and their measured values. In addition, as Comparative Example 8.9, two types of alumina dispersion-strengthened copper alloys (aluminum oxide content: 1.5% by volume, 3.0% by volume,
Volume %) round bars were obtained and similar tests were conducted on these round bars.

The results are also listed in Table 2. Note that Table 2 also shows the local maximum temperature during reduction.

As is clear from Table 2, the dispersion-strengthened copper alloys of Comparative Examples 1 to 9 have a 0 and 2% yield strength of 40 kg /
For materials with am2 or higher, the electrical conductivity at room temperature will not exceed 85% IACS, and for materials with electrical conductivity at room temperature of 85% IACS or higher, the 0 and 2% proof stress at room temperature will not exceed 40 kg/llI2.

In contrast, the dispersion-strengthened copper alloys of Examples 1 to 9 have an electrical conductivity of 85% IAC3 or higher at room temperature, a 0 and 2% proof stress of 40 kg/mta2 or higher at room temperature, and
It was confirmed that it has both high electrical conductivity and high strength.

Next, the processed test pieces cut out from the dispersion-strengthened copper alloy billets of Examples 2 to 4 and Comparative Example 5.9 were rolled at room temperature, and the rolling rate nj was determined until cracking occurred. These results are shown in Table 3.

Table 3 As shown in Table 3, Examples 2 to 4 had a high rolling reduction rate before cracking and good secondary workability, whereas Comparative Examples 5 and 9 had a high rolling reduction rate until cracking occurred. It was confirmed that the rolling rate was low and the secondary workability was low.

Next, an example of a high magnetic field generating coil formed of a dispersion-strengthened copper alloy according to the present invention will be described.

First, a dispersion-strengthened copper alloy billet was produced in the same manner as in Example 3 above, except that the mixed gas flow rate and pure hydrogen flow rate were set to 2042/g+1n in the reduction step. The flow rate was increased here because the amount of raw material charged was increased. Regarding this bit, the electrical conductivity at room temperature and 550° C. was measured, and the thermal conductivity at room temperature was measured. Further, a tensile test piece was cut out from this billet, and the 0 and 2% proof stress, tensile strength, and elongation at room temperature and 550°C were measured. These results are shown in Table 4.

Next, this billet was made into an outer diameter of 165 wms and an inner diameter of 88 m.
5. It was machined into a cylindrical shape with a height of 125° C., and then cut through in a spiral shape by electric discharge machining to produce an 11-turn magnetic field generating coil as shown in FIG.

This coil (water-cooled magnet) was placed in a stainless steel water-cooled container and placed inside a superconducting magnet that generates a 14.3 T (Teslan) magnetic field.

Then, while cooling the coil by flowing high-pressure water into the water-cooled container, a direct current of 1050 OA was passed through the coil, and the magnetic flux density in the center space of the water-cooled magnet was 23.2. It was T. After the magnetic field was generated, the coil was taken out and inspected, and no cracks or deformations were found in the coil.

As a comparative example, a commercially available alumina dispersion-strengthened copper alloy (aluminum oxide content 0.9
Volume %; Aluminum solid solution amount in copper matrix 0.07% by weight
) was heat-treated at 900°C for 1 hour in a pure argon stream, a coil having the same shape as in the above example was made, and a similar magnetic field generation test was conducted. The magnetic flux density of the OT was measured. After the magnetic field was generated, the coil was removed and inspected, and significant deformation was observed.

In this comparative example, electrical conductivity, thermal conductivity, 0.2% yield strength, tensile strength, and elongation were also measured in the same manner as in the examples prior to manufacturing the coil.

The results are also shown in Table 4.

Table 4 Next, examples of resistance welding electrodes made of the dispersion-strengthened copper alloy according to the present invention will be described.

First, a dispersion-strengthened copper alloy billet was produced in the same manner as in Example 3 above. Next, this billet was processed into a round bar by cold groove roll rolling, and its electrical conductivity, thermal conductivity, tensile strength, elongation, and Vickers hardness were determined, and the results shown in Table 5 were obtained. .

Next, an electrode as shown in FIG. 4 was manufactured from the round bar by machining. As shown in this figure, the tip of this electrode has a truncated cone shape with a tip diameter of 4 ml and an inclination angle α of 45°. Using this electrode, a spot welding test was conducted on a steel plate with a thickness of 1 mm.

At this time, the welding current was 550OA, and the repetition rate was approximately 1
Welding was carried out under the welding conditions of 3 times/sec. As a result, no change was observed in the shape of the tip of the electrode even after 5,000 welding points were performed continuously, and the electrode tip was in a state where continued use was possible.

As a comparative example, a commercially available alumina dispersion-strengthened copper alloy (aluminum oxide-containing FF13) manufactured by an internal oxidation method was used.
．． A round bar was manufactured from a billet (0 volume %) by cold groove roll rolling, an electrode having the same shape as in the example was manufactured by machining, and a spot welding test on a steel plate was conducted under the same welding conditions. As a result, a good welding condition was maintained up to 4,500 welding points, but beyond this point, enlarged deformation of the electrode tip was observed, the current per small area decreased, and the quality of the welded part was reduced. started to decrease. In this comparative example, electrical conductivity, thermal conductivity, tensile strength, elongation, and Vickers hardness were determined in the same manner as in the examples prior to the production of the electrode.

The results are also shown in Table 5.

Table 5 Next, examples of composite superconducting wires having a base material made of dispersion-strengthened copper alloy according to the present invention will be described.

First, a dispersion-strengthened copper alloy billet was produced in the same manner as in Example 3 above. Next, the electrical conductivity of this billet at room temperature was measured. Further, a tensile test piece was cut out from this billet, and the 0 and 2% proof stress, tensile strength, and elongation at room temperature were determined by nj.

These results are shown in Table 6.

As shown in Figure 5, from this billet, the outer diameter is 45,
A round bar with a length of 120 mg+ is finished, and 80 holes with a diameter of 3.6 mm are formed to form the metal base material 11, and the holes have an outer diameter of 3.6 mm.
55am Nb-Ti superconducting member 12 (46.5% by weight
A composite superconducting wire material was formed by inserting 80 pieces of Ti, the remainder being Nb. Thereafter, normal processing and heat treatment were repeated to obtain a composite superconducting wire with a diameter of 0.21. Table 7 shows the results of measuring the characteristics of this composite superconducting wire.

As a comparative example, a commercially available alumina dispersion-strengthened copper alloy (aluminum oxide content 3.0
Volume %; solid solution of aluminum in copper matrix m0.13% by weight
) was heat-treated at 900°C for 1 hour in a pure argon stream, and a composite superconducting wire using this billet as a base material was prepared in the same manner as in the above example, and the properties were similarly determined. 01 was established. As a result, the characteristics shown in Table 7 were obtained. From Table 7, it can be confirmed that the Examples are superior to the Comparative Examples in all properties of filament uniformity, critical current density, tensile strength, and residual resistance ratio. In particular, a significant difference was observed in the residual resistance ratio. In this comparative example as well, the electrical conductivity, tensile strength, 0.2% yield strength, and elongation of the base material were measured in the same manner as in the examples prior to the production of the composite superconducting wire. The results are also shown in Table 6.

Table 6 Next, examples of high electrical conductivity springs made of a dispersion-strengthened copper alloy according to the present invention will be described.

First, a dispersion-strengthened copper alloy billet was produced in the same manner as in Example 3 above. This billet is then cold rolled. A spring sample was prepared by processing a thin plate with a thickness of 0315 mm. This sample was tested for electrical conductivity, thermal conductivity, tensile strength, elongation, and micro-Vickers hardness. Furthermore, the spring limit value was measured, and the performance (650° C.) of brazing to the electrode was evaluated. SM4 as an electrode
76: Using a composite material of MOS2 + gral) hlte/Ag, brazing was performed on BAg-1.

These results are shown in Table 8.

As Comparative Example A, a commercially available alumina dispersion-strengthened copper alloy (aluminum oxide content: 30
Volume %; Aluminum solid solution amount in copper matrix 0.13% by weight
) A thin plate with a thickness of 0.15 m was produced by cold rolling. In addition, as comparative examples B and C, commercially available phosphor bronze (4,5%5N-0,03%P-Cu) and beryllium copper (1,9%Be-0,2%Co-0,5%
A billet of Fe-Cu) is cold rolled to a thickness of 0.
A 15 mm thin plate was produced. These Comparative Examples A to C were also evaluated in the same manner as in the Examples.

The results are also shown in Table 8.

As shown in Table 8, Examples are better than Comparative Examples A to C.
It was confirmed that the spring exhibits superior characteristics as a high electrical conductivity spring compared to the above.

Next, an example of a lead frame formed of a dispersion-strengthened copper alloy according to the present invention will be described.

First, a dispersion-strengthened copper alloy billet was produced in the same manner as in Example 3 above. Next, this billet was processed into a thin plate with a thickness of 0.15■■ by cold rolling, and heated at 650°C.
After heat treatment for 1 hour, the electrical conductivity, thermal conductivity, tensile strength, elongation, and micro-Vickers hardness were measured, and the results shown in Table 9 were obtained.

Next, a lead frame was made from this thin plate and a mounting test was carried out (results showed that good characteristics were obtained).

As a comparative example, a commercially available alumina dispersion-strengthened copper alloy (aluminum oxide content 3.0
% by volume) to a thickness of 0.15 m by cold rolling from a billet.
After preparing a thin plate of m and heat treating it at 650°C for 1 hour, the electrical conductivity, thermal conductivity, tensile strength,
Elongation and micro-Vickers hardness were measured. The results are also shown in Table 9. As shown in this table, the Examples showed better results than the Comparative Examples in all items. Furthermore, when a lead frame was actually manufactured from this thin plate and a mounting test was performed, the characteristics were lower than those of the example.

Table 9 [Effects of the Invention] According to the present invention, a dispersion-strengthened copper alloy having both high electrical conductivity and high strength can be obtained. Furthermore, it is possible to provide a method for manufacturing such a dispersion-strengthened copper alloy through simple steps with good reproducibility.

Furthermore, magnetic field generating coils, resistance welding electrodes, composite superconducting wires, highly electrically conductive springs, and lead frames having excellent properties can be obtained using such dispersion-strengthened copper alloys.

[Brief explanation of the drawing]

Figure 1 shows the relationship between the amount of each solid solution element added to copper and the electrical resistivity; Figure 2 is a schematic diagram to explain the method for measuring the average diameter of the copper matrix region; FIG. 4 is a cross-sectional view showing an embodiment of the resistance welding electrode according to the present invention; FIG.
The figure is a sectional view showing an embodiment of a composite superconducting wire according to the present invention. 11; Fundamental discussion, 12: Superconducting core wire #*oihiS 17L (1-1 Town-) Figure 1 Applicant's agent Patent attorney Takehiko Suzue Figure 2 Figure 3 Figure 4 Figure 5 Figure 1. Display of the case Patent Application No. 1-240755 2, Name of the invention: Dispersion-strengthened copper alloy and its manufacturing method 3, Relationship with the amended case Patent applicant (307) Toshiba Corporation 4, Agent 3, Kasumigaseki, Chiyoda-ku, Tokyo No. 7-2, 100 Telephone: 03 (502) 3181 (Main Representative) 7. Contents of Amendment (1) The scope of the claims will be corrected as shown in the attached sheet. (2) In the 11th line of page 13 of the specification, the phrase "average diameter" should be corrected to "average diameter." (3) In the fourth line of page 21 of the specification, the phrase "to copper alloy" is corrected to "copper alloy." (4) On page 27, line 10 of the specification, the phrase "for electrical conductivity" is corrected to "electrical conductivity." (5) On page 28 of the specification, lines 6 and 7, it says, "Do you directly apply plastic working or machining to the copper alloy?"
Correct to "copper alloy as is". (6) Lines 12, 13 and 1 of page 34 of the specification
In the fourth line, the words "electrical conductivity" are corrected to "electrical conductivity." (7) Table 2 on page 36 of the specification is corrected as shown in the attached sheet. (8) In the second line of page 39 of the specification, the word "bit" is corrected to "billet." (9) Table 8 on page 48 of the specification is corrected as shown in the attached sheet. (10) Table 9 on page 50 of the specification is corrected as shown in the attached sheet. (11) Figure 4 is corrected as shown in the attached sheet. 2. Claims (1) An average diameter of a matrix region having a copper matrix and dispersed particles contained in the copper matrix in a range of 0.5 to 6% by volume, where no dispersed particles are present. is 0.3 μm or less, and the total amount of solid solution elements contained in the copper matrix is such that when that amount is added to pure copper, the electrical conductivity decreases by 5% IACS or less. A dispersion-strengthened copper alloy characterized by: (2) All or part of the dispersed particles are formed of aluminum oxide, and the copper matrix is 0.04fflff.
The dispersion-strengthened copper alloy according to claim 1, containing i% or less of solid solution aluminum and other unavoidable impurities. (3) 0.29g resistant cuff that is 111% room temperature! l<40k
g/am” or more, and the electrical conductivity is 85% IA
The dispersion-strengthened copper alloy according to claim 2, characterized in that the copper alloy has a strength of CS or higher. (4) The dispersed particles include aluminum oxide, zirconium oxide, titanium oxide, silicon oxide, magnesium oxide, yttrium oxide, chromium oxide, aluminum nitride, silicon nitride, titanium nitride, boron nitride, titanium carbide, boron carbide, and titanium boride. The dispersion-strengthened copper alloy according to claim 1, characterized in that it is composed of one or more selected from the group consisting of: (5) A mixed powder non-formation process in which a mixed powder is formed by mechanically crushing and mixing copper oxide and a dispersed particle raw material that is chemically more stable than copper oxide in a reducing atmosphere, and this mixed powder A reduction step for selectively reducing the copper oxide contained therein, a molding step for molding the selectively reduced mixed powder, and a molded body obtained by the molding step is fired to form a copper matrix and dispersed particles. a firing step for forming a sintered body, and the reducing step is carried out while maintaining the mixed powder at a temperature of 1065° C. or lower. (6) It has a copper matrix and dispersed particles contained in the copper matrix in a range of 0.5 to 6% by volume, and the average diameter of the matrix region where no dispersed particles are present is 0.3 μm or less. A dispersion-strengthened copper alloy in which the total amount of solid solution elements contained in the copper matrix is such that when the amount is added to pure copper, the electrical conductivity decreases by 5% IACS or less. A magnetic field generating coil characterized by being formed of. (7) It has a copper matrix and dispersed particles contained in the copper matrix in a range of 0.5 to 6% by volume, and the average diameter of the matrix region where no dispersed particles are present is 0.3 μm or less. A dispersion-strengthened copper alloy in which the total amount of solid solution elements contained in the copper matrix is such that when the amount is added to pure copper, the electrical conductivity decreases by 5% IACS or less. A resistance welding electrode characterized by being formed of. (8) It has a copper matrix and dispersed particles contained in the copper matrix in a range of 0.5 to 6% by volume, and the average diameter of the matrix region where no dispersed particles are present is 0.3 μm or less. A dispersion-strengthened copper alloy in which the total amount of solid solution elements contained in the copper matrix is such that when the amount is added to pure copper, the electrical conductivity decreases by 5% IACS or less. 1. A composite superconducting wire comprising a base material made of , and a superconducting core wire embedded in the base material. (9) It has a copper matrix and dispersed particles contained in the copper matrix in a range of 0.5 to 6% by volume, and the average diameter of the matrix region where no dispersed particles are present is 0.3 μm or less. A dispersion-strengthened copper alloy in which the total amount of solid solution elements contained in the copper matrix is such that when the amount is added to pure copper, the electrical conductivity decreases by 5% IACS or less. A highly electrically conductive spring made of (10) It has a copper matrix and dispersed particles contained in the copper matrix in a range of 0.5 to 6% by volume, and the average diameter of the matrix region where no dispersed particles are present is 0.3 μm or less. A dispersion-strengthened copper alloy in which the total amount of solid solution elements contained in the copper matrix is such that when the amount is added to pure copper, the electrical conductivity decreases by 5% IACS or less. A lead frame characterized by being formed of. Figure 4

Claims (10)

[Claims] (1) It has a copper matrix and dispersed particles contained in the copper matrix in a range of 0.5 to 6% by volume, and the average diameter of the matrix region where no dispersed particles are present is 0.3 μm or less. The total amount of solid solution elements contained in the copper matrix is such that when added to pure copper, the electrical conductivity decreases by 5% IACS or less. Dispersion strengthened copper alloy. (2) All or part of the dispersed particles are formed of aluminum oxide, and the copper matrix contains 0.04% by weight or less of solid solution aluminum and other unavoidable impurities. The dispersion-strengthened copper alloy according to claim 1. (3) 0.2% proof stress at room temperature is 40kg/mm^2
The dispersion-strengthened copper alloy according to claim 2, wherein the dispersion-strengthened copper alloy has a conductivity of 85% IACS or higher. (4) The dispersed particles include aluminum oxide, zirconium oxide, titanium oxide, silicon oxide, magnesium oxide, yttrium oxide, chromium oxide, aluminum nitride, silicon nitride, titanium nitride, boron nitride, titanium carbide, boron carbide, and titanium boride. The dispersion-strengthened copper alloy according to claim 1, characterized in that it is composed of one or more selected from the group consisting of: (5) A mixed powder non-formation step in which a mixed powder is formed by mechanically pulverizing and mixing copper oxide and a dispersed particle raw material that is chemically more stable than copper oxide in a reducing atmosphere; A reduction step for selectively reducing copper oxide, a molding step for molding the selectively reduced mixed powder, and sintering to have a copper matrix and dispersed particles by firing the compact obtained by the molding step. a firing step for forming a dispersion-strengthened copper alloy, the reduction step being carried out while maintaining the mixed powder at a temperature of 1065° C. or lower. (6) It has a copper matrix and dispersed particles contained in the copper matrix in a range of 0.5 to 6% by volume, and the average diameter of the matrix region where no dispersed particles are present is 0.3 μm or less. A dispersion-strengthened copper alloy in which the total amount of solid solution elements contained in the copper matrix is such that when the amount is added to pure copper, the electrical conductivity decreases by 5% IACS or less. A magnetic field generating coil characterized by being formed of. (7) It has a copper matrix and dispersed particles contained in the copper matrix in a range of 0.5 to 6% by volume, and the average diameter of the matrix region where no dispersed particles are present is 0.3 μm or less. A dispersion-strengthened copper alloy in which the total amount of solid solution elements contained in the copper matrix is such that when the amount is added to pure copper, the electrical conductivity decreases by 5% IACS or less. A resistance welding electrode characterized by being formed of. (8) It has a copper matrix and dispersed particles contained in the copper matrix in a range of 0.5 to 6% by volume, and the average diameter of the matrix region where no dispersed particles are present is 0.3 μm or less. A dispersion-strengthened copper alloy in which the total amount of solid solution elements contained in the copper matrix is such that when the amount is added to pure copper, the electrical conductivity decreases by 5% IACS or less. 1. A composite superconducting wire comprising a base material made of , and a superconducting core wire embedded in the base material. (9) It has a copper matrix and dispersed particles contained in the copper matrix in a range of 0.5 to 6% by volume, and the average diameter of the matrix region where no dispersed particles are present is 0.3 μm or less. A dispersion-strengthened copper alloy in which the total amount of solid solution elements contained in the copper matrix is such that when the amount is added to pure copper, the electrical conductivity decreases by 5% IACS or less. A highly electrically conductive spring characterized by being formed of. (10) It has a copper matrix and dispersed particles contained in the copper matrix in a range of 0.5 to 6% by volume, and the average diameter of the matrix region where no dispersed particles are present is 0.3 μm or less. A dispersion-strengthened copper alloy in which the total amount of solid solution elements contained in the copper matrix is such that when the amount is added to pure copper, the electrical conductivity decreases by 5% IACS or less. A lead frame characterized by being formed of.