KR20060120276A - Copper alloy and method for production thereof - Google Patents

Abstract

A copper alloy which has a specific chemical composition, the balance being Cu and impurities, wherein the total number of pieces of precipitates and inclusions having a particle diameter of 1 mum or more satisfies the relationship represented by the following formula (1): logN <= 0.4742 + 17.629 x exp(-0.1133 x X) --- (1) where N represents the total number of pieces of precipitates and inclusions per unit area (number of pieces/mm2), and X represents the particle diameter (mum) of precipitates and inclusions; and a method for producing the copper alloy, which comprises, subsequent to melting and casting, cooling the cast product at a cooling rate of 0.5°C/s or more at least in a temperature region from the temperature of the cast product immediately after casting to 450°C. It is desirable that, after the above cooling, the product is further subjected to a working treatment in a temperature region of 600°C or lower and then to a heat treatment for 30 seconds or longer in a temperature region of 150 to 750°C, and, more desirably, the working and heating treatments are carried out two or more times.

Description

Copper alloy and its manufacturing method {COPPER ALLOY AND METHOD FOR PRODUCTION THEREOF}

The present invention relates to a copper alloy which can be produced at low cost without requiring a solution treatment, and which is excellent in both mechanical properties and electrical conductivity, and a method for producing the same. Examples of the copper alloy include electric and electronic components, safety tools, and the like.

Examples of electrical and electronic components include the following. In the field of electronics, a connector for a personal computer, a semiconductor socket, an optical pickup, a coaxial connector, an IC checker pin, etc. are mentioned. In the communication field, there are mobile phone parts (connectors, battery terminals, antenna parts), submarine repeater objects, connectors for exchangers, and the like. In the automotive field, various electrical components such as relays, various switches, micromotors, diaphragms, and various terminals are mentioned. In the aerospace and aerospace sectors, there may be mentioned landing gears for aircrafts. Examples of medical and analytical instruments include medical connectors and industrial connectors. In the home appliance field, relays for home appliances such as air conditioners, optical pickups for game consoles, and card media connectors may be mentioned.

Examples of safety tools include tools such as excavation rods, spanners, chain blocks, hammers, drivers, benches, and nippers, which are used in places where there is a risk of ignition and explosion from flames such as ammunition and coal mines.

Conventionally, Cu-Be alloys aimed at reinforcing by aging precipitation of Be are known as copper alloys used in the above electrical and electronic parts, and this alloy contains a considerable amount of Be. Since this alloy is excellent in both tensile strength and electrical conductivity, it is widely used as a material for springs. However, Be oxide is produced in the manufacturing process of Cu-Be alloy and the process of processing this alloy to various components.

Be is a substance that is harmful to the environment after Pb and Cd. In particular, since a large amount of Be is contained in a conventional Cu-Be alloy, it is necessary to provide a Be oxide treatment step in manufacturing and processing the copper alloy, and the manufacturing cost increases, which is a problem in the recycling process of electrical and electronic components. Becomes

Thus, Cu-Be alloy is a material which has a problem in an environmental problem. For this reason, the appearance of a material excellent in both tensile strength and electrical conductivity is expected to be minimized as much as possible to reduce elements harmful to the environment such as Be.

Patent Document 1 discloses a copper alloy in which precipitation of Ni ₂ Si known as cor songye alloy has been proposed. The Corson-based alloy has a tensile strength of 750 to 820 MPa and a conductivity of about 40%. Among alloys containing no harmful elements such as Be, the tensile strength and the conductivity are relatively good.

However, this alloy has a limit in either of its high strength and high electrical conductivity, and remains a problem in terms of product change as shown below. This alloy is to have a curing aging by precipitation of Ni ₂ Si. Then, when the content of Ni and Si is reduced to increase the conductivity, the tensile strength is remarkably lowered. On the other hand, in order to increase the amount of deposition of Ni ₂ Si, even if the amount of Ni and Si is increased, there is a limit to the increase in tensile strength, and the conductivity is significantly lowered. For this reason, the Corson-based alloy has a poor balance of tensile strength and electrical conductivity in a region with high tensile strength and a region with high electrical conductivity, thereby narrowing product variation. This is for the following reason.

The electrical resistance (or electrical conductivity, reciprocal) of the alloy is determined by electron scattering and varies greatly depending on the type of element dissolved in the alloy. Since the Ni dissolved in the alloy significantly increases the electrical resistance value (remarkably lowers the conductivity), the conductivity decreases when Ni is increased in the Corson-based alloy. On the other hand, the tensile strength of the copper alloy is obtained by age hardening. The tensile strength improves as the amount of precipitate increases, and the finer the precipitate is dispersed. In the case of a corson-based alloy, only the precipitated particles are Ni ₂ Si, and therefore, there is a limit to increasing the strength in terms of precipitation amount and in terms of dispersion state.

Patent Literature 2 discloses a copper alloy containing elements such as Cr and Zr and having good wire bonding properties in which surface hardness and surface roughness are defined. As described in the examples, the copper alloy is manufactured on the basis of hot rolling and solution treatment.

However, in order to perform hot rolling, it is necessary to trim the surface in order to prevent hot cracking and scale removal, and the yield falls. In addition, since it is often heated in the air, active additive elements such as Si, Mg, Al and the like are easily oxidized. This causes a lot of problems, such as the coarse internal oxides produced resulting in deterioration of the properties of the final product. In addition, hot rolling and solution treatment require enormous energy. As described above, in the copper alloy described in Reference Document 2, since the premise of hot working and solution treatment, there is a problem in terms of reduction in manufacturing cost, energy saving, etc. It causes a problem of deterioration of characteristics (in addition to tensile strength and electrical conductivity, bending workability and fatigue characteristics).

On the other hand, as the material for the safety tool, mechanical properties comparable to tool steel, such as strength and wear resistance, are required, and sparks that cause explosion are not required, that is, excellent flame resistance. For this reason, Cu-Be alloys aimed at reinforcement by the aging precipitation of copper alloys having high thermal conductivity, particularly Be, have been used in safety tool materials. As mentioned above, although Cu-Be alloy is a material with many environmental problems, nevertheless, Cu-Be alloy has been used abundantly as a safety tool material for the following reason.

Fig. 1 is a diagram showing the relationship between the electrical conductivity [IACS (%)] and the thermal conductivity [TC (W / m · K)] of the copper alloy. As shown in Fig. 1, both are in a 1: 1 relationship, and increasing the conductivity (IACS (%)) increases the thermal conductivity [TC (W / m · K), in other words, the flame resistance If a sudden force is applied due to a blow or the like when the tool is used, a spark is generated because specific components in the alloy are burned by the heat generated by the impact or the like. Since steel has a low thermal conductivity of less than 1/5 of the thermal conductivity of steel, local temperature rise is likely to occur, because steel contains C, causing a reaction of `` C + O ₂ → C0 ₂ '' In fact, it is known that spark does not occur in pure iron that does not contain C. It is easy to generate spark in other metals, such as Ti or Ti alloy, which is one of the thermal conductivity of copper. / 20 Very low, and, since this reaction takes place in the "Ti + O ₂ → TiO _2". In addition, Figure 1 summarizes the data shown in the Non-Patent Document 2.

However, as described above, the conductivity [IACS (%)] and the tensile strength [TS (MPa)] are in a trade-off relationship, and it is very difficult to simultaneously raise both, and in the related art, they have a high tensile strength as high as that of tool steel. It is because there was no copper alloy other than said Cu-Be alloy which has sufficient high thermal conductivity TC.

Patent Document 1: Japanese Patent No. 2572042

Patent Document 2: Japanese Patent No. 2714561

Non-Patent Document 1: Industrial Heating, Vo1.36, No.3 (1999), Published by Japan Industrial Laboratories Association, page 59

[Non-Patent Document 2] New Products Data Book, Pyeongseong August 1, 9, Published by the Japan Prodigy Association, pages 328-355

The first object of the present invention is to provide a copper alloy which is rich in product variation, excellent in ductility and workability, and also excellent in performance required for safety tool materials, ie, thermal conductivity, abrasion resistance, and flame resistance. have. The 2nd object of this invention is to provide the manufacturing method of the said copper alloy.

The term "rich in product variation" means that the balance between conductivity and tensile strength is adjusted to the same level as that of Cu-Be alloy or higher than that of Cu-Be alloy by adjusting finely the addition amount and / or manufacturing conditions. That means you can adjust to a lower level.

In addition, "the balance of electrical conductivity and tensile strength is a level higher than or equal to Cu-Be alloy" means the state which satisfy | fills following formula (a) specifically ,. Hereinafter, this state will be referred to as "a state where the balance between tensile strength and electrical conductivity is very good".

TS≥648.06 + 985.48 × exp (-0.0513 × IACS) ... (a)

However, TS in the formula (a) means tensile strength (MPa), and IACS means conductivity (%).

The bending workability is also preferably at least the same level as that of conventional alloys such as Cu-Be alloys. Specifically, the test piece is subjected to a 90 ° bending test at various curvature radii, and the minimum curvature radius R at which no cracking occurs is measured, and the bending workability is obtained by the ratio B (= R / t) of the plate thickness t. Can be evaluated. The range of favorable bending workability shall satisfy B <= 2.0 in the board | plate material with tensile strength TS of 800 Mpa or less, and satisfy | filling the following formula (b) in the board | plate material with tensile strength TS exceeding 800 Mpa.

B≤41.2686-39.4583 × exp [-{(TS-615.675) /2358.08} ² ] ... (b)

Copper alloys as safety tools require wear resistance in addition to the properties of tensile strength TS and conductivity IACS described above. Therefore, in the case of the copper alloy for safety tools, it is necessary to have the same level as the tool steel as the wear resistance. Specifically, the hardness at room temperature is 250 or more as a Vickers hardness, and shall be excellent in wear resistance.

This invention makes the summary a copper alloy shown to following (A)-(C), and the manufacturing method of the copper alloy shown to following (D).

(A) 0.1 to 20 masses in one or two or more kinds selected from Zn, Sn, Ag, Mn, Fe, Co, Al, Ni, Si, Mo, V, Nb, Ta, W, Ge, Te and Se %, Wherein the balance consists of copper and impurities, and the particle size of the precipitates and inclusions present in the alloy having a particle size of 1 µm or more, and the total number of precipitates and inclusions satisfy the relationship shown in the following formula (1). Copper alloy made.

logN≤0.4742 + 17.629 × exp (-0.1133 × X) ... (1)

However, N means the total number of precipitates and inclusions per unit area (pieces / mm 2), and X means the particle size of the precipitates and inclusions (μm).

(B) In mass%, it contains any one selected from Ti: 0.01-5%, Zr: 0.01-5%, and Hf: 0.01-5%, and further includes Zn, Sn, Ag, Mn, Fe, Co, It contains 0.01 to 20% of one or two or more kinds selected from Al, Ni, Si, Mo, V, Nb, Ta, W, Ge, Te, and Se, and the balance consists of copper and impurities, and is present in the alloy. The copper alloy characterized by the particle diameter of the thing of 1 micrometer or more in said precipitate and inclusions, and the total number of precipitates and inclusions satisfy | filling the relationship shown by following formula (1).

logN≤0.4742 + 17.629 × exp (-0.1133 × X) ... (1)

However, N means the total number of precipitates and inclusions per unit area (pieces / mm 2), and X means the particle size of the precipitates and inclusions (μm).

(C)% by mass, containing Cr: 0.01 to 5%, Zn, Sn, Ag, Mn, Fe, Co, Al, Ni, Si, Mo, V, Nb, Ta, W, Ge, Te And 0.01-20% in total of one or two or more selected from Se, the balance consisting of copper and impurities, and the particle size of the precipitates and inclusions present in the alloy having a particle size of 1 μm or more, and the sum of the precipitates and inclusions. The copper alloy whose number satisfy | fills the relationship shown by following formula (1).

logN≤0.4742 + 17.629 × exp (-0.1133 × X) ... (1)

However, N means the total number of precipitates and inclusions per unit area (pieces / mm 2), and X means the particle size of the precipitates and inclusions (μm).

The copper alloy according to any one of the above (A) to (C) is 0.001 to 2% by mass, in place of a part of copper, and in one or two or more kinds selected from Mg, Li, Ca, and rare earth elements, and / Or one selected from P, B, Bi, Tl, Rb, Cs, Sr, Ba, Tc, Re, Os, Rh, In, Pd, Po, Sb, Au, Ga, S, Cd, As and Pb Or you may contain 0.001-3 mass% in 2 or more types in total. Alternatively, 0.1-5 mass% of Be may also be included. In these alloys, it is preferable that the ratio of the maximum value of the average content and the minimum value of the average content in the small region of at least one alloy element is 1.5 or more. Moreover, it is preferable that the crystal grain diameters of these alloys are 0.01-35 micrometers.

(D) The casting piece obtained by solvent-casting and casting the copper alloy which has the chemical composition as described in any one of said (A)-(C) above at least in the temperature range from the casting piece temperature immediately after casting to 450 degreeC. The particle diameter of the particle | grains whose particle diameter is 1 micrometer or more among the precipitates and inclusions which exist in an alloy characterized by cooling at 0.5 degreeC / s or more, and the total number of precipitates and inclusions satisfy | fill the relationship shown by following formula (1) Method of producing an alloy.

logN≤0.4742 + 17.629 × exp (-0.1133 × X) ... (1)

However, N means the total number of precipitates and inclusions per unit area (pieces / mm 2), and X means the particle size of the precipitates and inclusions (μm).

After said cooling, it is preferable to process in the temperature range of 600 degrees C or less, or further, to heat-process maintained for 30 second or more in the temperature range of 150-750 degreeC. The processing in the temperature range of 600 degrees C or less may be performed after the last heat treatment in which the processing in the temperature range of 600 ° C. or less and the heat treatment maintained in the temperature range of 150 to 750 ° C. for 30 seconds or more may be performed a plurality of times.

In the present invention, the precipitate is a metal or a compound of copper and an additional element, or a compound of additional elements. For example, Cu ₄ Ti in a Ti additive, Cu ₉ Zr _{2 in a} Zr additive, and metal Cr in a Cr additive. Precipitates respectively. Incidentally, the inclusions are metal oxides, metal carbides, metal nitrides, and the like.

(The best mode for carrying out the invention)

EMBODIMENT OF THE INVENTION Hereinafter, embodiment of this invention is described. In addition, in the following description, "%" regarding content of each element means the "mass%."

1. About the copper alloy of this invention

(a) On chemical composition

In the copper alloy of the present invention, Zn, Sn, Ag, Mn, Fe, Co, Al, Ni, Si, Mo, V, Nb, Ta, W, Ge, Te, and Se (hereinafter, these elements are referred to as "first group"). Element) and 0.1-20% of two or more of the two or more kinds in total, and the balance has a chemical composition of copper and impurities.

All of these elements are elements having an effect of improving corrosion resistance and heat resistance while maintaining a balance between strength and conductivity. This effect is exerted when these elements contain 0.1% or more in total. However, when these content is excessive, electrical conductivity will fall. Therefore, when including these elements, it is necessary to set it as 0.1 to 20% of range in 1 type, or 2 or more types of total content. In particular, Ag and Sn contribute to high strength by fine precipitation, and therefore, it is preferable to use Ag and Sn actively. In addition, when the following 2nd element is included, since the intensity | strength can be ensured by a 2nd element, the lower limit of a 1st element can fall to 0.01%.

The alloy of the present invention may contain any one selected from Ti: 0.01 to 5%, Zr: 0.01 to 5%, and Hf: 0.01 to 5% instead of a part of the copper, and may contain Cr: 0.01 to 5.0%. good. Hereinafter, these elements are called "second group element."

Any one of Ti, Zr, or Hf selected from Ti: 0.01% to 5%, Zr: 0.01% to 5%, and Hf: 0.01% to 5% is an effective element for improving tensile strength. May be contained in the copper alloy of the present invention. The effect of improving the strength is remarkable when the content of these elements is 0.01% or more. However, when the content exceeds 5%, the strength increases but the conductivity deteriorates. In addition, segregation of Ti, Zr or Hf is caused at the time of casting, which makes it difficult to obtain a homogeneous casting piece, and cracks and crushing are likely to occur during subsequent processing. Therefore, it is preferable that all the content at the time of containing any 1 type of Ti, Zr, and Hf shall be 0.01 to 5.0%. In order to obtain a very good balance of tensile strength and electrical conductivity, it is more preferable to contain 0.1% or more of these elements.

Cr: O.O1 ~ 5%

Cr is an element effective for improving the tensile strength without increasing the electrical resistance. In order to acquire the effect, it is preferable to contain 0.01% or more. In particular, it is preferable to contain 0.1% or more in order to obtain a state in which a balance of tensile strength and conductivity which is about the same or higher than that of the Cu-Be alloy is very good. On the other hand, when the Cr content is more than 5%, the metal Cr is coarsened and adversely affects bending characteristics, fatigue characteristics, and the like. Therefore, when it contains Cr, it is preferable to make the content into 0.01 to 5%.

The copper alloy of the present invention, in order to increase the high temperature strength, instead of a part of the copper, 0.001 ~ 2%, or a total of 0.001 ~ 2%, or two or more of one selected from Mg, Li, Ca and rare earth elements, respectively It is preferable to include%. Hereinafter, these are called "third group elements."

Mg, Li, Ca and rare earth elements are elements that combine with oxygen atoms in the copper matrix to produce fine oxides and increase high temperature strength. The effect becomes remarkable when the total content of these elements is 0.001% or more. However, when the content exceeds 2%, there is a problem that the above effects are saturated, the electrical conductivity is lowered, and the bending workability is deteriorated. Therefore, the total content in the case of containing one or two or more selected from Mg, Li, Ca, and rare earth elements is preferably 0.001 to 2%. In addition, rare earth elements mean Sc, Y, and a lanthanoid, and the single element of each element may be added, and mischmetal may be added.

The copper alloy of the present invention is P, B, Bi, Tl, Rb, Cs, Sr, Ba, Tc, Re instead of part of the copper for the purpose of widening the width (ΔT) of the liquidus and solidus vessels when the alloy is injected. , Os, Rh, In, Pd, Po, Sb, Au, Ga, S, Cd, As and Pb is preferably 1 to 3% each, or 0.001 to 3% of two or more types in total Do. As, Pd and Cd are harmful elements, so it is preferable not to use them as much as possible. Hereinafter, these are called "fourth group elements." Incidentally, in the case of quench solidification, ΔT increases due to the so-called supercooling phenomenon. Here, as a target, ΔT in the thermal equilibrium state is considered.

 All of these elements have the effect of lowering the solidus line and widening ΔT. If the ΔT is large, a certain time can be secured from the injection to the solidification, so that the injection becomes easy, but if the ΔT is too wide, the strength in the low temperature region decreases, causing cracking at the end of the solidification. , So-called solder brittleness occurs. For this reason, it is preferable to make (DELTA) T into the range of 50-200 degreeC.

C, N and O are elements usually included as impurities. These elements form metal elements and carbides, nitrides and oxides in the alloy. If these precipitates or inclusions are fine, they may be actively added because they have the effect of strengthening the alloy, particularly high temperature strength, like precipitates such as a metal or a compound of copper and an additional element, or a compound of additional elements. For example, O has an effect of forming an oxide to increase high temperature strength. This effect is easy to be obtained in an alloy containing elements that are easy to form oxides such as Mg, Li, Ca, and rare earth elements, Al, and Si. In this case, however, it is necessary to select a condition in which employment O remains. Residual solid-solution oxygen needs attention because it may generate a so-called hydrogen bottle, which becomes H ₂ O gas during heat treatment under a hydrogen atmosphere, causing a blister or the like to deteriorate the quality of the product.

When these elements exceed 1%, respectively, they become coarse precipitates or inclusions and lower ductility. Therefore, it is desirable to limit each to 1% or less. More preferably, it is 0.1% or less. In addition, when H is contained as an impurity in the alloy, H ₂ gas remains in the alloy and causes a rolling ratio or the like, so that the content is preferably as small as possible.

Be is an element that contributes to precipitation strengthening of the alloy without significantly impairing conductivity. In order to acquire this effect, it is preferable to contain 0.1 mass% or more. However, when the content exceeds 5%, not only the electrical conductivity is lowered but also the ductility is lowered, resulting in deterioration of workability in rolling, bending and the like. Therefore, when it contains Be, it is preferable to make the content into 0.1 to 5%.

(b) the total number of precipitates and inclusions;

In the copper alloy of the present invention, it is necessary for the particle size of the precipitate and inclusions present in the alloy to have a particle size of 1 µm or more, and the total number of precipitates and inclusions to satisfy the relationship shown in the following formula (1).

logN≤0.4742 + 17.629 × exp (-0.1133 × X) ... (1)

However, N means the total number of precipitates and inclusions per unit area (pieces / mm 2), and X means the particle size of the precipitates and inclusions (μm). In formula (1), when the measured value of the particle diameter of a precipitate and an inclusion is 1.0 micrometer or more and less than 1.5 micrometers, X = 1 is substituted and when "alpha-0.5" micrometer or more is less than "alpha + 0.5" micrometer, X = (alpha) is An integer of 2 or more).

In the copper alloy of the present invention, the precipitate can be finely precipitated such as a metal, a compound of copper and an additional element, or a compound of additional elements, thereby improving the strength without lowering the conductivity. These increase the strength by precipitation hardening. Solid solution Cr, Ti, and Zr are reduced by precipitation, and the conductivity of the copper matrix is closer to that of pure copper.

However, when coarse precipitates of these precipitates and inclusions such as metal oxides, metal carbides, and metal nitrides are coarse and precipitated at 20 µm or more, ductility decreases, for example, cracking or sintering during bending or drilling in a connector. It becomes easy to generate a ruck. Moreover, when used, it may adversely affect a fatigue characteristic or an impact resistance characteristic. In particular, when a coarse Ti-Cr compound is produced during cooling after solidification, cracking and cracking are likely to occur in subsequent processing steps. In addition, since the hardness increases excessively in the aging treatment step, fine precipitation of these precipitates and the like is inhibited, and the high strength of the copper alloy becomes impossible. This problem becomes remarkable when the particle size of the precipitates and inclusions present in the alloy having a particle size of 1 µm or more, the total number of precipitates and inclusions and the relationship shown in the above formula (1) are not satisfied.

For this reason, in this invention, it was prescribed | regulated that it satisfy | fills the particle size of the thing of 1 micrometer or more in precipitates and inclusions which exist in an alloy, the total number of precipitates and inclusions, and the relationship shown by said formula (1). The total number of preferable precipitates and inclusions is a case of satisfying the relationship shown by following formula (2), and more preferable is a case of satisfying the relationship shown by following formula (3). Moreover, these particle diameters and the total number of precipitates and inclusions are requested | required by the method shown in an Example.

logN≤0.4742 + 7.9749 × exp (-0.1133 × X) ... (2)

logN≤0.4742 + 6.3579 × exp (-0.1133 × X) ... (3)

However, N means the total number of precipitates and inclusions per unit area (pieces / mm 2), and X means the particle size of the precipitates and inclusions (μm).

(c) Regarding the ratio of the maximum value of the average content and the minimum value of the content in the microregions of at least one alloy element.

In the copper alloy, when microstructures in which different concentrations of alloying elements are mixed, that is, periodic concentration changes occur, micro-diffusion of each element is suppressed and grain boundary movement is suppressed. have. As a result, the strength and ductility of the copper alloy are improved depending on the so-called hole patch side. The micro area refers to an area composed of 0.1 to 1 탆 diameter and substantially refers to an area corresponding to the irradiation area when subjected to X-ray analysis.

In addition, the area | region with which the alloy element concentration differs in this invention is the following two types.

(1) Basically, it has the same fcc structure as Cu, but the alloy element concentration is different. Since the alloy element concentrations are different, the lattice constants are generally different with the same fcc structure, and the degree of work hardening is naturally different.

(2) A fine precipitate dispersed in the fcc mother phase. Since the concentration of alloying elements is different, the dispersion of precipitates after processing and heat treatment is naturally different.

The mean content in the small region means a value in the analysis area, ie, an average value in the corresponding region, when concentrated at a beam diameter of 1 μm or less in X-ray analysis. According to the X-ray analysis, an analyzer having a field emission type electron gun is preferable. As for the analyzing means, an analytical method having a resolution of 1/5 or less of the concentration cycle is preferable, and more preferably 1/10. This is because if the analysis region is too large for the concentration cycle, the entirety is averaged, making it difficult to show the difference in concentration. In general, the probe diameter can be measured by X-ray analysis of about 1㎛.

Determining the material properties is the alloy element concentration in the mother phase and the fine precipitates. In the present invention, the difference in concentration between the microregions including the fine precipitates is a problem. Therefore, signals from coarse precipitates and coarse inclusions of 1 µm or more are disturbance factors. However, it is difficult to completely remove coarse precipitates or coarse inclusions from industrial materials, and it is necessary to remove disturbance factors from the coarse precipitates and inclusions in the analysis. To do this, do the following:

That is, first, although the material is used, line analysis is carried out with an X-ray analyzer having a probe diameter of about 1 탆 diameter to grasp the periodic structure of the concentration. As described above, the analysis method is determined such that the probe diameter is about 1/5 or less of the concentration cycle. The length of the line analysis is then determined to be long enough for the period to appear at least three times. Under this condition, m analyzes (preferably 10 times or more) are performed, and the maximum and minimum values of the concentrations are determined with respect to the respective linear analysis results.

The number of the maximum value and the minimum value is m, but 20% is cut off from the larger value with respect to each and averaged. By the above, the signal from the above-mentioned coarse precipitate and inclusion can remove a disturbance factor.

Concentration ratio is calculated | required by ratio of the maximum value and minimum value which removed the disturbance factor mentioned above. In addition, the concentration ratio may be obtained with respect to an alloy element having a periodic concentration change of about 1 μm or more, and does not consider a change in concentration of an atomic level of about 10 nm or less such as spinodal decomposition or fine precipitates.

The reason why the ductility is improved by finely distributing the alloying elements will be described in detail. If the concentration of the alloying element occurs, the mechanical properties of the two parts are different because the degree of solid solution hardening of the material in the high concentration part and the low concentration part, or the dispersion state of the precipitate as described above is different. During the deformation of such a material, a relatively soft low concentration portion is first hardened, followed by a deformation of a relatively hard high concentration portion. In other words, since a plurality of work hardenings occur in the whole material, for example, in the case of tensile deformation, high elongation is exhibited, and a separate softening effect is exhibited. Thus, in the alloy in which the periodic concentration change of the alloying element occurs, it is possible to exhibit high ductility advantageous in bending and the like while maintaining the balance between the conductivity and the tensile strength.

In addition, the electrical resistance (inverse of the conductivity) mainly corresponds to a phenomenon in which electron transfer decreases due to scattering of solid elements, and is hardly affected by macro defects such as grain boundaries. There is no deterioration.

These effects become remarkable when the ratio of the maximum value of the average content and the minimum value of the average content in the microregion of the at least one alloy element in the mother phase (hereinafter, simply referred to as "concentration ratio") is 1.5 or more. The concentration ratio is not particularly limited, but if the concentration ratio is too large, there is a possibility that the fcc structure of the Cu alloy may not be maintained, and there may be a problem such that the difference in the electrochemical properties becomes too large to cause local corrosion. . Therefore, the concentration ratio is preferably 20 or less, more preferably 10 or less.

(d) About Grain Diameter

When the grain size of the copper alloy is made small, it is advantageous to increase the strength, the ductility is improved, and the bendability and the like are improved. However, when the grain size is less than 0.01 µm, the high temperature strength tends to be lowered, and when it exceeds 35 µm, the ductility decreases. Therefore, it is preferable that a grain size is 0.01-35 micrometers. More preferable particle diameter is 0.05-30 micrometers. More preferably, it is 0.1-25 micrometers.

2. About the manufacturing method of the copper alloy of this invention

In the copper alloy of the present invention, inclusions such as metal oxides, metal carbides, and metal nitrides that interfere with microprecipitation such as metals, compounds of copper and additive elements, or compounds between additive elements, are produced at the point immediately after the solidification of the cast pieces. Easy to be Such inclusions are subjected to a solution treatment after casting, for example, and it is difficult to solidify the solution even if the solution temperature is raised. The solution treatment at high temperature only causes coagulation and coarsening of inclusions.

Therefore, in the production method of the copper alloy of the present invention, the casting piece obtained by melting and casting the copper alloy having the above chemical composition is at least 0.5 ° C in a temperature range of at least 450 ° C from the casting piece temperature immediately after casting. By cooling at a cooling rate of / s or more, the particle size of the precipitates and inclusions in the alloy having a particle size of 1 µm or more, and the total number of precipitates and inclusions satisfy the relationship shown in the following formula (1).

logN≤0.4742 + 17.629 × exp (-0.1133 × X) ... (1)

However, N means the total number of precipitates and inclusions per unit area (pieces / mm 2), and X means the particle size of the precipitates and inclusions (μm).

After this cooling, it is preferable to perform processing in the temperature range of 600 degrees C or less, or further, to heat-process maintained for 30 seconds or more in the temperature range of 150-750 degreeC. The processing in the temperature range of 600 ° C. or less and the heat treatment maintained for 30 seconds or more in the temperature range of 150 ° C. to 750 ° C. may be performed a plurality of times. In addition, you may process in the temperature range of 600 degrees C or less after the last heat processing.

(a) Cooling rate in the temperature range from the casting piece temperature at least after the main structure to 450 ° C: 0.5 ° C / s or more

Precipitates, such as a metal, a compound of copper and an addition element, or a compound of addition elements, produce in the temperature range of 280 degreeC or more. In particular, when the cooling rate in the temperature range from the casting piece temperature immediately after casting to 450 degreeC is low, inclusions, such as a metal oxide, a metal carbide, and a metal nitride, produce | generate coarse, and the particle diameter is 20 micrometers or more, and several hundred micrometers. There is work to reach. Moreover, said precipitate is also coarsened to 20 micrometers or more. In the state where such coarse precipitates and inclusions are produced, not only there is a risk of cracking or bending during subsequent processing, but also the precipitation hardening action of the precipitates in the aging process is impaired and the alloy cannot be made high in strength. . Therefore, in at least this temperature range, it is necessary to cool the casting piece at a cooling rate of 0.5 ° C / s or more. The larger the cooling rate, the better. The preferred cooling rate is 2 ° C / s or more, and more preferably 10 ° C / s or more.

(b) Processing temperature after cooling: Temperature range below 600 ° C

In the manufacturing method of the copper alloy of this invention, the casting piece obtained by casting is cooled by predetermined | prescribed conditions, and is finalized only by the combination of a process and an aging heat treatment, without going through a hot process, such as hot rolling and a solution treatment. Leads to the product.

Processing, such as rolling and scribing, may be 600 degrees C or less. For example, when continuous casting is adopted, these processing may be performed in the cooling process after solidification. In the temperature range exceeding 600 ℃, precipitates such as compounds of metals or copper with additive elements or compounds between additive elements are coarsened at the time of processing to reduce the ductility, impact resistance and fatigue characteristics of the final product. Lowers. Further, if these precipitates are coarsened at the time of processing, they cannot be precipitated finely in the aging treatment, resulting in insufficient strength of the copper alloy.

Since the lower the processing temperature, the dislocation density during processing increases, so that precipitates, such as a metal, a compound of copper and additional elements, or a compound of additional elements, can be more finely precipitated by the subsequent aging treatment. For this reason, higher strength can be provided to a copper alloy. Therefore, a preferable processing temperature is 450 degrees C or less, and more preferably 250 degrees C or less. Most preferable is 200 degrees C or less. 25 degrees C or less may be sufficient.

In addition, it is preferable to perform processing in said temperature range by making the processing rate (section reduction rate) into 20% or more. More preferably, it is 50% or more. If the processing at such a processing rate is performed, the potential introduced therein becomes a precipitation nucleus at the time of aging treatment, resulting in miniaturization of the precipitate, shortening the time required for precipitation, and reducing the solid solution element harmful to conductivity. Can be realized early.

(c) Aging treatment conditions: Aging treatment maintained at a temperature range of 150 to 750 ° C. for 30 seconds or more precipitates precipitates such as metals, compounds of copper and additive elements, or compounds of additive elements, thereby increasing the strength of the copper alloy. In addition, it is effective in reducing conductivity elements (Cr, Ti, etc.) that cause harm to conductivity and improving conductivity. However, when the treatment temperature is lower than 150 ° C, it takes a long time for diffusion of the precipitation element, thereby lowering the productivity. On the other hand, if the treatment temperature is higher than 750 ° C, the precipitate becomes coarse, which not only makes it impossible to increase the strength due to the precipitation hardening action, but also decreases the ductility, impact resistance and fatigue characteristics. For this reason, it is preferable to perform an aging treatment in the temperature range of 150-750 degreeC. Preferable aging treatment temperature is 200-700 degreeC, More preferably, it is 250-650 degreeC. Most preferable is 280-550 degreeC.

If the aging treatment time is less than 30 seconds, even if the aging treatment temperature is set high, the desired amount of precipitation cannot be secured, and if it exceeds 72 hours, the treatment cost increases. Therefore, it is preferable to perform aging treatment for 30 second or more in the temperature range of 150-750 degreeC. This treatment time is preferably 5 minutes or more, more preferably 10 minutes or more. Most preferred is at least 15 minutes. Although the upper limit of processing time is not specifically determined, It is preferable to set it as 72 hours or less from a viewpoint of processing cost. In addition, when the aging treatment temperature is high, the aging treatment time can be shortened.

In addition, since the aging treatment prevents generation of scale due to oxidation of the surface, it is preferable to carry out in a reducing atmosphere, an inert gas atmosphere, or a vacuum of 20 Pa or less. The treatment in such an atmosphere also ensures excellent plating properties.

The above processing and aging treatment may be repeated as necessary. When repeated, the desired amount of precipitation can be obtained in a short time than in one treatment (processing and aging treatment), and finer precipitates such as metals, compounds of copper and additional elements, or compounds of additional elements are finer. Can be precipitated. At this time, for example, when the treatment is performed twice, it is preferable to slightly lower the second aging treatment temperature (20 to 70 ° C. lower) than the first aging treatment temperature. Such heat treatment is because, when the second aging treatment temperature is higher, the precipitates produced during the first aging treatment are coarsened. Also in the aging treatment after the third time, as described above, it is preferable to lower the aging treatment temperature performed before. In addition, you may process in the temperature range of 600 degrees C or less after the last heat processing.

(d) Other

In the manufacturing method of the copper alloy of this invention, although there is no restriction | limiting in particular in the conditions other than said manufacturing conditions, for example, melt | dissolution, casting, etc., What is necessary is just to carry out as follows, for example. Dissolution may be carried out in a non-oxidizing or reducing atmosphere. This is because a so-called hydrogen bottle or the like occurs in the subsequent process, when the dissolved oxygen in the molten copper increases, water vapor is generated and blisters are generated. In addition, coarse oxides such as Ti and Cr, which are easy to oxidize, are formed, and when this remains until the final product, ductility and fatigue characteristics are significantly reduced.

The method for obtaining the cast piece is preferably continuous casting in terms of productivity and solidification speed. However, other methods such as an ingot method may be used as long as the method satisfies the above conditions. In addition, a preferable injection temperature is 1250 degreeC or more. More preferably, it is 1350 degreeC or more. At this temperature, Cr, Ti, and Zr can be sufficiently dissolved, and precipitates such as inclusions of metal oxides, metal carbides, and metal nitrides, compounds of metal or steel and additional elements, and compounds of additional elements are not produced. Because it does not.

In the case of obtaining the casting piece by continuous casting, a method using a graphite mold usually made of copper alloy is recommended from the viewpoint of lubricity. As a mold material, refractory materials, such as zirconia, which are hard to react with Ti, Cr, or Zr which are main alloying elements may be used.

1 is a diagram showing a relationship between electrical conductivity and thermal conductivity.

2 is a diagram showing a relationship between tensile strength and electrical conductivity of each example.

Figure 3 is a schematic diagram showing a casting method by the Duville method,

Short description of the sign

1: mold

(Example 1)

The copper alloy which has the chemical composition shown in Tables 1-3 was vacuum-solvented by the high frequency melting furnace, it was inject | poured into the mold made from zirconia, and the casting piece of thickness 12mm was obtained. Rare earth elements were added alone or misch metal of each element.

TABLE 1

TABLE 2

Table 3

 The obtained casting piece was cooled at the predetermined cooling rate by spray cooling in the temperature range from 950 degreeC to 450 degreeC which is the temperature after casting (temperature just after taking out from a mold). The thermocouple embedded in the mold was used to measure the temperature change at a predetermined place, and the surface temperature after the casting piece left the mold was measured by a contact thermometer. By using these results and electrothermal analysis together, the average cooling rate of the casting piece surface up to 450 degreeC was computed. The solidification start point was obtained by preparing 0.2 g of the molten metal in each component, and by thermal analysis in continuous cooling at a predetermined speed.

From the obtained casting piece, the rolled material of thickness 10mm x width 80mm x length 150mm was produced by cutting and cutting. For comparison, some rolled materials were subjected to solution heat treatment at 950 ° C. These rolled materials were subjected to rolling (first rolling) with a reduction ratio of 80% at room temperature to form a plate having a thickness of 2 mm, and subjected to aging treatment (first aging) under predetermined conditions to prepare test materials. Regarding some test materials, furthermore, a rolling reduction (second rolling) with a reduction ratio of 95% was performed at room temperature to a thickness of 0.1 mm, and aging treatment (second aging) was performed under predetermined conditions. These manufacturing conditions are shown in Tables 4-7.

In this manner, the total number, tensile strength, electrical conductivity, and bendability of the precipitates and inclusions per unit area and unit area were determined by the following method. These results are written together in Tables 4-7.

<Total number of precipitates and inclusions>

After the mirror surface was polished to the surface perpendicular to the rolling surface and parallel to the rolling direction, and etched in that state or with an aqueous ammonia solution, a field of view of 1 mm x 1 mm at 100 times magnification by an optical microscope. Was observed. Then, the value obtained by measuring the long diameter (the length of the straight line which can be dragged long in a particle on condition that it does not contact a grain boundary in coating) is defined as particle diameter. In formula (1), when the measured value of the particle diameter of a precipitate and an interference | inclusion is 1.0 micrometer or more and less than 1.5 micrometers, X = 1 is substituted, and when "alpha-0.5" micrometer or more is less than "alpha + 0.5" micrometer, X = (alpha) ((alpha) Is an integer of 2 or more). In addition, the total number n ₁ is calculated by making one half of the line crossing the 1 mm x 1 mm field of view and one within the border line for each particle diameter, and the number N (= n) at 10 fields selected arbitrarily. _1, the average value (n / 10) of the _{+ n 2 + ··· + n 10} ) is defined as the total number of precipitates and inclusions for each of the grain size of the sample.

<Concentration ratio>

The cross section of the alloy was polished, and at a beam diameter of 0.5 µm, 50 µm lengths were randomly analyzed ten times by X-ray analysis with a 2000-fold field of view, and the maximum content of each alloying element in each ray analysis and The minimum value was obtained. Regarding the maximum value and the minimum value, the average value of the maximum value and the minimum value was calculated | required about the remaining 8 times from which two large values were removed, and the ratio was computed as density ratio.

Tensile strength

The specimen 13B specified in JIS Z 2201 was taken so that the tensile direction and the rolling direction might be parallel from the specimen, and according to the method specified in JIS Z 2241, the tensile strength at room temperature (25 ° C) [TS (MPa). )].

<Conductivity>

From the specimen, the test piece having a width of 10 mm and a length of 60 mm is taken so that the longitudinal direction and the rolling direction are parallel, a current is flown in the longitudinal direction of the test piece, and the potential difference between both ends of the test piece is measured. Saved resistance. Subsequently, the electrical resistance (resistance) per unit volume was calculated from the volume of the test piece measured with a micrometer, and the conductivity [IACS (%)] was determined from the ratio with the resistivity of 1.72 µΩ · cm of the standard sample annealed with polycrystalline copper.

<Bending processability>

From the specimen, a plurality of test pieces each having a width of 10 mm and a length of 60 mm were taken so that the longitudinal direction and the rolling direction were parallel, and the curvature radius (inner diameter) of the bent portion was changed to perform a 90 ° bending test. The bending part of the test piece after a test was observed from the outer diameter side using the optical microscope. And the minimum radius of curvature in which no crack generate | occur | produced was R, and ratio B (= R / t) with thickness t of the test piece was calculated | required.

TABLE 4

TABLE 5

TABLE 6

TABLE 7

In the column of bending workability, "evaluation" indicates a case where the tensile strength TS satisfies B ≤ 2.0 in a sheet of 800 MPa or less, and the tensile strength TS satisfies the following formula (b) in a sheet exceeding 800 MPa. And the case where these are not satisfied was made into "x".

B≤41.2686-39.4583 × exp [-{(TS-615.675) /2358.08} ² ] ... (b)

2 is a diagram showing a relationship between tensile strength and electrical conductivity of each embodiment. As shown in Tables 4 to 7 and FIG. 2, in Examples 1 to 67 of the present invention, since the total composition of the chemical composition, the concentration ratio, and the precipitates and inclusions is within the range defined by the present invention, the tensile strength and the electrical conductivity described above ( a) was satisfied. Therefore, these alloys can be said that the balance between conductivity and tensile strength is at the same level or higher than that of the Be-added copper alloy. Thus, it can be seen that the copper alloy of the present invention is rich in changes in tensile strength and electrical conductivity. In addition, Examples 1, 6, 11, 16, 34, 36, 37, 39, 41, 64, 65, and 66 of the present invention are examples of fine adjustment of the addition amount and / or production conditions in the same ingredient system. In these alloys, there is a relationship between tensile strength and electrical conductivity indicated by "Δ" in FIG. Bending characteristics were also good.

On the other hand, in Comparative Examples 1-4, 6, 10, 12-14, 16, and 17, any one content is out of the range prescribed | regulated by this invention, its bending workability is inferior, and electrical conductivity is low, Comparative Examples 1-3 and 17 After the second rolling, the cracks were severe and the sample was impossible, and thus the evaluation of the characteristics was not achieved.

In addition, Comparative Examples 5, 9, 11, and 15 subjected to the solution treatment at 950 ° C. had poor tensile strength and poor bendability.

(Example 2)

In order to evaluate the application to the safety tool, a sample was produced by the following method, and abrasion resistance (Vickers hardness) and flame resistance were evaluated.

The alloy having the chemical composition shown in Table 8 was dissolved in the air at a high frequency furnace and cast in a mold by the Duville method. That is, the mold 1 is held in the state shown in FIG. 3 (a), the molten metal at about 1300 ° C. is poured into the mold 1 while securing a reducing atmosphere with charcoal powder, and this is shown in FIG. 3 (b). It was inclined and rotated as shown in Fig. 3 (c) to solidify to produce a cast piece. The mold 1 was made of cast iron having a thickness of 50 mm, and the pipe 1 was piped to allow air cooling by drilling a cooling hole therein. The casting piece was made wedge-shaped so that pouring might be easy, the bottom surface was 30x300 mm, the top surface was 50x400 mm, and the height was 700 mm.

From the lower end of the obtained casting piece, the part to 300 mm was extract | collected, and after surface grinding, cold rolling (30-10 mm)-heat processing (375 degreeC x 16 h) was performed, and the board of thickness 10mm was obtained. Using these plates, the total number, the tensile strength, the electrical conductivity and the bending workability of the precipitates and inclusions were examined by the above method, and the wear resistance, the thermal conductivity and the flame resistance were examined by the following method. These results are shown in Table 8.

<Wear resistance>

A test piece of width 10 mm x length 10 mm was taken from the specimens, and the surface perpendicular to the rolling surface and parallel to the rolling direction was mirror polished, and the load was 25 ° C. by the method specified in JIS Z 2244. Vickers hardness at 9.8 N was measured.

<Thermal conductivity>

Thermal conductivity [TC (W / m · K)] calculated | required said conductivity [IACS (%)] from the formula "TC = 14.804 + 3.8172 * IACS" described in FIG.

Flame resistance

The flame test according to the method prescribed | regulated to JISG 0566 was performed using the table grinder of 12000 rpm, and the presence or absence of the flame was confirmed by eye observation.

Moreover, the average cooling rate to 450 degreeC calculated | required based on the liquidus line obtained from the thermoelectric calculation was measured by inserting a thermocouple in the position of 5 mm below the mold inner wall surface of a 100 mm position from the lower end surface, and was 10 degreeC / s.

TABLE 8

As shown in Table 8, in Examples 68-70 of the present invention, the wear resistance was good, the thermal conductivity was large, and no spark was observed. On the other hand, since both the comparative examples 18 and 19 do not satisfy the chemical composition prescribed | regulated by this invention and the relationship prescribed | regulated by Formula (1), thermal conductivity is small and a flame is observed.

According to the present invention, a copper alloy having abundant product variations, excellent in high temperature strength and workability, and also excellent in performance required for safety tool materials, that is, excellent in thermal conductivity, abrasion resistance, and flame resistance, and a manufacturing method thereof. Can be provided.

Claims (13)

0.1 to 20% by mass of one or two or more selected from Zn, Sn, Ag, Mn, Fe, Co, Al, Ni, Si, Mo, V, Nb, Ta, W, Ge, Te, and Se; , The remainder consisting of copper and impurities, the particle size of the precipitates and inclusions present in the alloy having a particle size of 1 μm or more, and the total number of precipitates and inclusions satisfy the relationship shown in the following formula (1) . logN≤0.4742 + 17.629 × exp (-0.1133 × X) ... (1) However, N means the total number of precipitates and inclusions per unit area (pieces / mm 2), and X means the particle size of the precipitates and inclusions (μm). In mass%, it contains any one selected from Ti: 0.01 to 5%, Zr: 0.01 to 5% and Hf: 0.01 to 5%, and further includes Zn, Sn, Ag, Mn, Fe, Co, Al, Ni , Si, Mo, V, Nb, Ta, W, Ge, Te and Se one or two or more selected from the sum of 0.01 to 20%, the balance consists of copper and impurities, precipitates present in the alloy and A copper alloy, wherein the particle size of the inclusion having a particle size of 1 µm or more, and the total number of precipitates and inclusions satisfy the relationship shown in the following formula (1). logN≤0.4742 + 17.629 × exp (-0.1133 × X) ... (1) However, N means the total number of precipitates and inclusions per unit area (pieces / mm 2), and X means the particle size of the precipitates and inclusions (μm). By mass%, Cr: 0.01-5% is contained, and in Zn, Sn, Ag, Mn, Fe, Co, Al, Ni, Si, Mo, V, Nb, Ta, W, Ge, Te and Se 0.01-20% of the selected one or two or more kinds, the balance of copper and impurities, the particle size of the precipitate and inclusions in the alloy having a particle size of 1㎛ or more, and the total number of precipitates and inclusions are as follows The copper alloy which satisfy | fills the relationship shown by Formula (1). logN≤0.4742 + 17.629 × exp (-0.1133 × X) ... (1) However, N means the total number of precipitates and inclusions per unit area (pieces / mm 2), and X means the particle size of the precipitates and inclusions (μm). The copper according to any one of claims 1 to 3, wherein, in place of a part of the copper, O.001 to 2% by mass is included in one or two or more kinds selected from Mg, Li, Ca, and rare earth elements. alloy. The compound according to any one of claims 1 to 4, instead of part of the synonyms, and also P, B, Bi, Tl, Rb, Cs, Sr, Ba, Tc, Re, Os, Rh, In, Pd, Po, Sb, A copper alloy comprising 0.001 to 3% by mass in total of one or two or more selected from Au, Ga, S, Cd, As, and Pb. The copper alloy according to any one of claims 1 to 5, further comprising 0.1 to 5% by mass of Be instead of a part of the copper. The copper alloy according to any one of claims 1 to 6, wherein a ratio between the maximum value of the average content and the minimum value of the average content in the minute region of at least one alloy element is 1.5 or more. The grain diameter is 0.01-35 micrometers, The copper alloy in any one of Claims 1-7 characterized by the above-mentioned. The casting piece obtained by solvent-casting and casting the copper alloy which has the chemical composition of any one of Claims 1-6 is cooled 0.5 degreeC / s or more in the temperature range from the casting piece temperature immediately after casting to 450 degreeC at least. A method for producing a copper alloy, wherein the particle size of the precipitate and inclusions present in the alloy having a particle size of 1 µm or more, and the total number of precipitates and inclusions satisfy the relationship represented by the following formula (1). logN≤0.4742 + 17.629 × exp (-0.1133 × X) ... (1) However, N means the total number of precipitates and inclusions per unit area (pieces / mm 2), and X means the particle size of the precipitates and inclusions (μm). The cooling rate of 0.5 degreeC / s or more in the temperature range from the casting piece temperature after a casting structure to 450 degreeC at least from the casting piece temperature after a casting structure which melted and cast the copper alloy which has the chemical composition of any one of Claims 1-6. And the particle size of the precipitates and inclusions in the alloy having a particle size of 1 µm or more and the total number of precipitates and inclusions represented by the following formula (1): Method for producing a satisfactory copper alloy. logN≤0.4742 + 17.629 × exp (-0.1133 × X) ... (1) However, N means the total number of precipitates and inclusions per unit area (pieces / mm 2), and X means the particle size of the precipitates and inclusions (μm). The cooling rate of 0.5 degrees C / s or more in the temperature range from the casting piece temperature immediately after casting to 450 degreeC at least from the casting piece temperature which casts the copper alloy which has the chemical composition of any one of Claims 1-6, and casts. After cooling in a furnace, and processed in a temperature range of 600 ℃ or less, it is used for a heat treatment that is maintained for 30 seconds or more in a temperature range of 150 ~ 750 ℃, the particle size of the precipitates and inclusions present in the alloy is 1㎛ or more The manufacturing method of the copper alloy in which the particle diameter of a thing, and the total number of precipitates and inclusions satisfy | fill the relationship shown by following formula (1). logN≤0.4742 + 17.629 × exp (-0.1133 × X) ... (1) However, N means the total number of precipitates and inclusions per unit area (pieces / mm 2), and X means the particle size of the precipitates and inclusions (μm). The manufacturing method of the copper alloy of Claim 11 which performs the process in the temperature range of 600 degrees C or less, and the heat processing maintained for 30 second or more in the temperature range of 150-750 degreeC. The manufacturing method of the copper alloy of Claim 11 or 13 which performs processing in the temperature range of 600 degrees C or less after the last heat processing.

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