WO2023157806A1

WO2023157806A1 - Copper alloy material, and resistor resistance material and resistor using copper alloy material

Info

Publication number: WO2023157806A1
Application number: PCT/JP2023/004822
Authority: WO
Inventors: 紳悟川田; 貴大佐々木; 俊太秋谷; 優樋口
Original assignee: 古河電気工業株式会社
Priority date: 2022-02-18
Filing date: 2023-02-13
Publication date: 2023-08-24
Also published as: JP7354481B1; TW202342774A; JPWO2023157806A1

Abstract

Provided are: a copper alloy material having excellent press punching workability and sufficiently high volume resistivity, as well as a small absolute value of thermoelectromotive force (EMF) relative to copper; and a resistor resistance material and a resistor using the copper alloy material.　The copper alloy material has an alloy composition containing 20.0-35.0 mass% of Mn, 6.5-17.0 mass% of Ni, 0-800 mass ppm of O, 0-800 mass ppm of C, and 60-800 mass ppm in total of O and C, with the remainder comprising Cu and inevitable impurities.

Description

Copper alloy material, resistance material for resistor and resistor using copper alloy material

The present invention relates to a copper alloy material, and a resistance material for a resistor and a resistor using the copper alloy material.

The metal materials used for resistors are required to have a stable resistance value even when the environmental temperature changes. In this regard, Cu--Mn--Ni alloys and Cu--Mn--Sn alloys are widely used as alloy materials constituting resistor materials because their resistance values do not easily change even when the environmental temperature changes.

However, these Cu--Mn--Ni alloys and Cu--Mn--Sn alloys are used in resistors designed to have a predetermined resistance value by forming circuits (patterns) using resistive materials, for example. , the volume resistivity is as low as less than 50×10 ⁻⁸ (Ω·m), so it is necessary to increase the resistance value of the resistor by reducing the cross-sectional area of the resistive material. In such resistors, when a large current is temporarily passed through the circuit, or when a large current is constantly passed through the circuit, the Joule heat generated in the resistive material with a small cross-sectional area increases and heats up. As a result, there is a problem that the resistance material is easily broken (melted) by heat.

Therefore, in order to suppress the reduction of the cross-sectional area of the resistor material, a resistor material with a higher volume resistivity is desired.

For example, in Patent Document 1, in a copper alloy containing Mn in the range of 23% by mass or more and 28% by mass or less and Ni in the range of 9% by mass or more and 13% by mass or less, the mass fraction of Mn and By configuring the mass fraction of Ni so that the thermoelectromotive force with respect to copper is less than ±1 ^μV /°C at 20°C, a high electrical resistance (volume resistivity ρ ) can be obtained, the thermoelectromotive force for copper (thermoelectromotive force for copper, EMF) is small, the temperature coefficient of electrical resistance is low, and the inherent electrical resistance is highly stable with respect to time (time invariance) It is possible to obtain a copper alloy having

Further, in Patent Document 2, a copper alloy containing Mn in the range of 21.0% by mass or more and 30.2% by mass or less and Ni in the range of 8.2% by mass or more and 11.0% by mass or less , the temperature coefficient of resistance (TCR) value x [ppm/°C] in the temperature range from 20°C to 60°C is in the range of -10 ≤ x ≤ -2 or 2 ≤ x ≤ 10, and the volume resistivity ρ is 80×10 ⁻⁸ [Ω・m] or more and 115×10 ⁻⁸ [Ω・m] or less, the cross-sectional area of the circuit of a resistor such as a chip resistor using a resistive material is reduced. In addition, it is possible to suppress an increase in the Joule heat of the resistance material.

Japanese Patent Publication No. 2016-528376 JP 2017-053015 A

In recent years, as electrical and electronic components have become smaller and more highly integrated, resistors and the resistive materials used in them have also become smaller. Resistance materials used for resistors are generally formed by cutting such as press punching, so in order to reduce the variation in resistance value, the copper alloy material must have excellent press punching workability. is required. In order to provide a copper alloy material with excellent press-punching workability, it is necessary to improve the dimensional accuracy of the cut surface during press-punching.

Furthermore, in recent years, resistors such as shunt resistors and chip resistors for the electrical system of electric vehicles have been required to have a high volume resistivity ρ, as well as high-precision resistors that can withstand high-temperature environments. High-precision copper alloys that can withstand high-temperature environments are also required for the copper alloys used in such resistors. More specifically, there is a demand for a copper alloy material that has a high volume resistivity ρ, a low electromotive force with copper even at high temperatures, and a small absolute value of the copper thermoelectromotive force (EMF).

Accordingly, an object of the present invention is to provide a copper alloy material having excellent press-punchability, sufficiently high volume resistivity, and a small absolute value of thermoelectromotive force (EMF) against copper, and the copper alloy The object of the present invention is to provide a resistance material for a resistor and a resistor using a material.

The present inventors contain Mn: 20.0 mass% or more and 35.0 mass% or less and Ni: 6.5 mass% or more and 17.0 mass% or less, and O: 0 mass ppm or more and 800 mass ppm or less and C: 0 mass ppm or more and 800 mass ppm or less and a copper alloy material having an alloy composition containing 60 mass ppm or more and 800 mass ppm or less in total of O and C, with the balance being Cu and inevitable impurities, For example, it has a sufficiently high volume resistivity ρ as a resistance material, and has a small absolute value of thermoelectromotive force (EMF) against copper in a temperature range from normal temperature (eg, 5 ° C. to 35 ° C.) to high temperature (eg, 80 ° C.), In addition, the present inventors have found that a copper alloy material having excellent press-punching workability can be obtained, and have completed the present invention.

In order to achieve the above object, the gist and configuration of the present invention are as follows.
(1) Mn: 20.0% by mass or more and 35.0% by mass or less and Ni: 6.5% by mass or more and 17.0% by mass or less, O: 0 mass ppm or more and 800 mass ppm or less and C: A copper alloy material having an alloy composition containing 0 mass ppm or more and 800 mass ppm or less, a total of 60 mass ppm or more and 800 mass ppm or less of O and C, and the balance being Cu and unavoidable impurities.
(2) Of the precipitated particles containing at least one of oxides and carbides observed within a viewing area of 10000 μm ² when viewed in a cross section orthogonal to the stretching direction during processing of the copper alloy material, the maximum The copper alloy material according to (1) above, wherein the number of coarse precipitated particles, which are precipitated particles having a size of more than 20 μm, is 3 or less.
(3) The alloy composition is Fe: 0.01% by mass or more and 0.50% by mass or less, Co: 0.01% by mass or more and 2.00% by mass or less, Sn: 0.01% by mass or more and 5.00% by mass. % or less, Zn: 0.01% by mass or more and 5.00% by mass or less, Cr: 0.01% by mass or more and 0.50% by mass or less, Ag: 0.01% by mass or more and 0.50% by mass or less, Al: 0.01% by mass or more and 1.00% by mass or less, Mg: 0.01% by mass or more and 0.50% by mass or less, Si: 0.01% by mass or more and 0.50% by mass or less, and P: 0.01% by mass % or more and 0.50% by mass or less, the copper alloy material according to (1) or (2) above, further containing at least one component selected from the group consisting of 0.50% by mass or less.
(4) A resistance material for a resistor, comprising the copper alloy material according to any one of (1) to (3) above.
(5) A resistor comprising the resistance material for a resistor according to (4) above.

According to the present invention, there is provided a copper alloy material having excellent press-punching workability, sufficiently high volume resistivity, and a small absolute value of thermoelectromotive force (EMF) against copper, and the copper alloy material. The resistive material for the resistor used and the resistor can be provided.

FIG. 2 is a schematic diagram showing a cut surface when the copper alloy material of the present invention is press-punched. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic diagram of an apparatus for measuring copper thermoelectromotive force (EMF) for test materials of the present invention examples and comparative examples. 1 shows an example of an optical microscope photograph of a cross section perpendicular to the stretching direction during working of the copper alloy material of Inventive Example 9, observed within a visual field area of 10000 μm ² . FIG. 10 shows a scanning electron microscope (SEM) photograph of a cut surface of the copper alloy material of Example 11 of the present invention, which is subjected to press punching, when viewed in a cross section including the thickness direction and the width direction. 1 shows a scanning electron microscope (SEM) photograph of a cut surface of the copper alloy material of Comparative Example 1 subjected to press-punching, viewed in a cross section including the thickness direction and the width direction.

A preferred embodiment of the copper alloy material of the present invention will be described in detail below. In addition, in the component composition of the alloy of the present invention, "% by mass" may be simply indicated as "%". Also, "mass ppm" may be simply indicated as "ppm".

The copper alloy material according to the present invention contains Mn: 20.0 mass% or more and 35.0 mass% or less and Ni: 6.5 mass% or more and 17.0 mass% or less, and O: 0 mass ppm or more and 800 mass ppm. ppm or less and C: 0 mass ppm or more and 800 mass ppm or less and an alloy composition containing 60 mass ppm or more and 800 mass ppm or less in total of O and C, with the balance being Cu and unavoidable impurities.

The copper alloy material of the present invention contains Mn in the range of 20.0% by mass to 35.0% by mass and Ni in the range of 6.5% by mass to 17.0% by mass. , the volume resistivity ρ is increased, and the absolute value of the thermoelectromotive force against copper (EMF, hereinafter sometimes simply referred to as “thermoelectromotive force against copper”) generated between the temperature environment of 0 ° C. and 80 ° C. becomes smaller, it is possible to improve the performance of the resistor even in a high-temperature environment.

In this regard, the copper alloys described in

Patent Documents

1 and 2 described above have a single phase with a face-centered cubic structure that is highly ductile. There is a problem that the resistance value of the resulting resistor varies.

However, the copper alloy material according to the present invention contains Mn in the range of 20.0% by mass or more and 35.0% by mass or less, and contains 60 ppm by mass or more of O and C in total, so that O and C When one or both of them combine with Mn to form an oxide or carbide, it is possible to increase the ratio of the shear plane in the cross section when the copper alloy material is press-punched. The larger the ratio of the sheared surface, the smaller the area of the sag and the fractured surface in the cross section. Therefore, the flatness of the cut surface can be improved, and the processing accuracy in press punching can be improved. As a result, it is possible to improve the accuracy of the resistor obtained from the copper alloy.

Further, the copper alloy material according to the present invention contains Mn in the range of 20.0% by mass or more and 35.0% by mass or less, and Ni in the range of 6.5% by mass or more and 17.0% by mass or less. At the same time, by containing O and C in a total amount of 800 mass ppm or less, embrittlement of the copper alloy material is made difficult to occur, so that the copper alloy material can be made stronger and easier to manufacture. .

As a result, the copper alloy material according to the present invention has excellent press-punching workability, has a sufficiently high volume resistivity ρ, and has a small absolute value of the copper thermoelectromotive force (EMF). It is possible to provide a material, a resistance material for a resistor using the same, and a resistor.

[1] Composition of copper alloy material <essential ingredients>
The alloy composition of the copper alloy material of the present invention contains, as essential components, Mn: 20.0% by mass or more and 35.0% by mass or less and Ni: 6.5% by mass or more and 17.0% by mass or less. be.

(Mn: 20.0% by mass or more and 35.0% by mass or less)
Mn (manganese) is an element that increases the volume resistivity ρ. In order to exhibit this effect and obtain a homogeneous copper alloy material, the Mn content is preferably 20.0% by mass or more, more preferably 22.0% by mass or more, and 24.0% by mass. % or more is more preferable. Here, by increasing the Mn content to 22.0% by mass or more or 24.0% by mass or more, the volume resistivity ρ of the copper alloy material can be further increased. On the other hand, when the Mn content exceeds 35.0% by mass, the melting point of the copper alloy material is lowered, making it difficult to control the production of the copper alloy material, especially the hot working, so that uniform properties can be obtained. becomes difficult. Therefore, the Mn content should be in the range of 20.0% by mass or more and 35.0% by mass or less.

(Ni: 6.5% by mass or more and 17.0% by mass or less)
Ni (nickel) is an element that adjusts the thermoelectromotive force (EMF) against copper in the positive direction. In order to exhibit this effect, Ni is preferably contained in an amount of 6.5% by mass or more. On the other hand, if the Ni content exceeds 17.0% by mass, it becomes difficult to obtain a uniform structure, and there is a risk that the volume resistivity ρ and the copper thermoelectromotive force (EMF) will change. In particular, the Ni content is in the range of 6.5% by mass or more and 17.0% by mass or less, from the viewpoint of obtaining a copper alloy material having desired properties and from the viewpoint of obtaining a copper alloy material that is easy to manufacture. It is preferably in the range of 12.0% by mass or more and more preferably in the range of 6.5% by mass or more and 9.0% by mass or less.

(One or two of O and C: 60 mass ppm or more and 800 mass ppm or less in total)
O (oxygen) and C (carbon) form oxides and carbides with Mn, thereby increasing the proportion of the sheared surface in the cross section when the copper alloy material is press-punched, thereby improving the press-punching process. At least one of these elements is essential because it has a property-enhancing effect. In order to exhibit this effect, the total content of O and C is preferably 60 ppm by mass or more, more preferably 100 ppm by mass or more. On the other hand, if the total amount of one or two of O and C exceeds 800 ppm by mass, the copper alloy material becomes embrittled and production becomes difficult. Therefore, from the viewpoint of achieving high strength and improving press punching workability, the total content of one or two of O and C is in the range of 60 mass ppm or more and 800 mass ppm or less, preferably 100 The range is from mass ppm to 800 mass ppm. The total content of one or two of O and C may be in the range of 60 mass ppm or more and 600 mass ppm or less, or in the range of 100 mass ppm or more and 600 mass ppm or less.

(O and C: 0 mass ppm or more and 800 mass ppm or less, respectively)
Here, the content of O is set in the range of 0 mass ppm or more and 800 mass ppm or less from the viewpoint of achieving high strength without embrittlement of the copper alloy material. Also, from the same viewpoint, the content of C should be in the range of 0 mass ppm or more and 800 mass ppm or less. One or both of the O content and the C content may be in the range of 0 mass ppm or more and 600 mass ppm or less.

<Optional Addition Ingredients>
The copper alloy material of the present invention contains, as optional additive components, Fe: 0.01% by mass or more and 0.50% by mass or less, Co: 0.01% by mass or more and 2.00% by mass or less, Sn: 0.01% by mass. 5.00% by mass or less, Zn: 0.01% by mass or more and 5.00% by mass or less, Cr: 0.01% by mass or more and 0.50% by mass or less, Ag: 0.01% by mass or more and 0.50% by mass % or less, Al: 0.01% by mass or more and 1.00% by mass or less, Mg: 0.01% by mass or more and 0.50% by mass or less, Si: 0.01% by mass or more and 0.50% by mass or less, and P : at least one component selected from the group consisting of 0.01% by mass or more and 0.50% by mass or less.

(Fe: 0.01% by mass or more and 0.50% by mass or less)
Fe (iron) is an element that adjusts the thermoelectromotive force (EMF) against copper in the positive direction. In order to exhibit this effect, Fe is preferably contained in an amount of 0.01% by mass or more. On the other hand, when the Fe content exceeds 0.50% by mass, it becomes difficult to obtain a uniform structure, which tends to cause variations in electrical performance. Therefore, the Fe content is preferably in the range of 0.01% by mass or more and 0.50% by mass or less.

(Co: 0.01% by mass or more and 2.00% by mass or less)
Co (cobalt) is an element that positively adjusts the thermoelectromotive force (EMF) against copper. In order to exhibit this effect, Co is preferably contained in an amount of 0.01% by mass or more. On the other hand, if the Co content exceeds 2.00% by mass, it becomes difficult to obtain a uniform structure, which tends to cause variations in electrical performance. Therefore, the Co content is preferably in the range of 0.01% by mass or more and 2.00% by mass or less.

(Sn: 0.01% by mass or more and 5.00% by mass or less)
Sn (tin) is a component that can be used to adjust the volume resistivity ρ. In order to exhibit this effect, it is preferable to contain 0.01% by mass or more of Sn. On the other hand, by setting the Sn content to 5.00% by mass or less, it is possible to make it difficult for the copper alloy material to become embrittled and reduce the manufacturability.

(Zn: 0.01% by mass or more and 5.00% by mass or less)
Zn (zinc) is a component that can be used to adjust the volume resistivity ρ. In order to exhibit this effect, it is preferable to contain 0.01% by mass or more of Zn. On the other hand, the Zn content may adversely affect the stability of the electrical performance of the resistor, such as the volume resistivity ρ and copper thermoelectric force (EMF), so it should be kept at 5.00% by mass or less. preferably.

(Cr: 0.01% by mass or more and 0.50% by mass or less)
Cr (chromium) is a component that can be used to adjust the volume resistivity ρ. In order to exhibit this effect, it is preferable to contain 0.01% by mass or more of Cr. On the other hand, the Cr content may adversely affect the stability of the electrical performance of the resistor, such as the volume resistivity ρ and copper thermoelectromotive force (EMF), so it is set to 0.50% by mass or less. preferably.

(Ag: 0.01% by mass or more and 0.50% by mass or less)
Silver (Ag) is a component that can be used to adjust the volume resistivity ρ. In order to exhibit this effect, it is preferable to contain 0.01% by mass or more of Ag. On the other hand, the Ag content may adversely affect the stability of the electrical performance of the resistor, such as the volume resistivity ρ and copper thermoelectromotive force (EMF), so it is set to 0.50% by mass or less. preferably.

(Al: 0.01% by mass or more and 1.00% by mass or less)
Al (aluminum) is a component that can be used to adjust the volume resistivity ρ. In order to exhibit this effect, it is preferable to contain 0.01% by mass or more of Al. On the other hand, the Al content is preferably 1.00% by mass or less because it may embrittle the copper alloy material.

(Mg: 0.01% by mass or more and 0.50% by mass or less)
Mg (magnesium) is a component that can be used to adjust the volume resistivity ρ. In order to exhibit this effect, it is preferable to contain 0.01% by mass or more of Mg. On the other hand, the Mg content is preferably 0.50% by mass or less because it may embrittle the copper alloy material.

(Si: 0.01% by mass or more and 0.50% by mass or less)
Si (silicon) is a component that can be used to adjust the volume resistivity ρ. In order to exhibit this effect, it is preferable to contain 0.01% by mass or more of Si. On the other hand, the Si content is preferably 0.50% by mass or less because it may embrittle the copper alloy material.

(P: 0.01% by mass or more and 0.50% by mass or less)
P (phosphorus) is a component that can be used to adjust the volume resistivity ρ. In order to exhibit this action, it is preferable to contain 0.01% by mass or more of P. On the other hand, since the P content may embrittle the copper alloy material, it is preferable to set it to 0.50% by mass or less.

(Total amount of optional additive components: 0.01% by mass or more and 5.00% by mass or less)
At least one (optionally added) component selected from the group consisting of Fe, Co, Sn, Zn, Cr, Ag, Al, Mg, Si and P, in order to obtain the effect of the above-described optional added component, It is preferable to contain 0.01% by mass or more. On the other hand, if the content of these optional additive components is too large, the electrical characteristics become unstable and the production of the copper alloy material becomes difficult, so the total content should be 5.00 mass % or less. is preferred.

<Remainder: Cu and inevitable impurities>
The remainder consists of Cu (copper) and unavoidable impurities other than the essential ingredients and optional additive ingredients described above. Incidentally, the "unavoidable impurities" referred to here generally refer to those present in the raw materials of copper-based products and those that are unavoidably mixed in during the manufacturing process. It is an impurity that is allowed because it does not affect the properties of copper-based products. Components that can be cited as inevitable impurities include, for example, nonmetallic elements such as sulfur (S) and metallic elements such as antimony (Sb). In addition, the upper limit of the content of these components can be 0.05% by mass for each of the above components, and 0.10% by mass for the total amount of the above components.

[2] Shape and metallographic structure of copper alloy material The shape of the copper alloy material of the present invention is not particularly limited, but the process of hot or cold stretching described later, press punching, etc. A plate material is preferable from the viewpoint of facilitating cutting. Here, in the case of a copper alloy material formed by rolling, such as a sheet material, the rolling direction can be the stretching direction. On the other hand, the copper alloy material of the present invention may be in the form of a strip such as a ribbon material, a wire such as a rectangular wire or a round wire, in addition to a plate or bar. By forming the shape of , it is possible to facilitate cutting of the end. In particular, in copper alloy materials having these shapes formed by wire drawing, drawing, or extrusion, any one of the wire drawing direction, the drawing direction, and the extrusion direction can be set as the drawing direction.

Here, the copper alloy material is observed in a cross section orthogonal to the drawing direction (drawing direction, drawing direction, extrusion direction) during processing, and oxides and carbides observed within a viewing area of 10000 μm ² Among the precipitated particles containing at least one of them, the number of coarse precipitated particles, which are precipitated particles having a maximum dimension of more than 20 μm, is preferably 3 or less. As a result, the oxides and carbides of manganese are dispersed more uniformly in the copper alloy material, and when the copper alloy material is press-punched, the proportion of the sheared surface in the cross section can be increased. It is possible to improve the punching workability and improve the dimensional accuracy of the copper alloy material after press punching. In particular, precipitated particles with a maximum dimension of more than 20 μm tend to form regions where oxides and carbides are sparse around the particles, which tends to make the cross section uneven when press-punched. It is preferable that the number contained in the alloy material is small. Therefore, from the viewpoint of improving the processing accuracy in press punching by making the cross section uniform when press punching, the number of coarse precipitated particles observed in the visual field area of 10000 μm ² is 3 or less. It is preferably 1 or less, and most preferably 0.

Measurement of the number of coarse precipitated particles containing oxides or carbides in this specification is performed by embedding in resin so that the cross section perpendicular to the stretching direction during processing of the copper alloy material is exposed. After that, the cross section perpendicular to the stretching direction is polished, and the exposed crystal is observed with an optical microscope with a 100 μm × 100 μm square as one field of view. This can be done by measuring the particle size of precipitated particles containing carbide.

[3] An example of a method for producing a copper alloy material The copper alloy material described above can be realized by controlling a combination of the alloy composition and the production process, and the production process is not particularly limited. Among them, the following method can be given as an example of a manufacturing process capable of obtaining the copper alloy material described above.

As an example of the method for producing a copper alloy material of the present invention, a copper-based material having substantially the same alloy composition as that of the copper alloy material described above is subjected to at least a casting step [step 1], a homogenization heat treatment step [step 2], a hot working step [step 3], a first cold working step [step 4], and a first annealing step [step 5].

(i) Casting step [Step 1]
In the casting step [step 1], a high-frequency melting furnace is used to melt a copper-based material having the above-described alloy composition in an inert gas atmosphere, which is a non-oxidizing atmosphere, or in a vacuum. An ingot having a predetermined shape (for example, thickness of 30 mm, width of 50 mm, and length of 300 mm) is produced. In addition, the alloy composition of the copper-based material may not always match completely with the alloy composition of the copper-based material manufactured by adhering or volatilizing in the melting furnace depending on the additive components in each manufacturing process. However, it has substantially the same alloy composition as that of the copper alloy material.

Here, in the casting step [Step 1], a copper-based material containing at least one of copper, manganese, nickel, graphite, and copper oxide, or copper, manganese, nickel, graphite, copper oxide, and the optional additive components described above is used. , melting and casting. Here, manganese has the feature of easily forming oxides and carbides, so by reacting with carbon constituting graphite and oxygen contained in copper oxide, oxides and carbides with few coarse precipitated particles are formed. Containing precipitated particles can be obtained. Therefore, the copper alloy material obtained through the above-described manufacturing method can contain oxides and carbides within the range of the alloy composition described above. can be improved.

In this casting step [Step 1], the molten copper-based material is held at a melting temperature in the range of 1100 ° C. or higher and 1250 ° C. or lower for a holding time of 2 hours or less, and then an average cooling rate of 0.5 ° C. or more per second. It is preferable to obtain an ingot by cooling to 600° C. or less. As a result, fine oxides and carbides can be dispersed in the ingot with high uniformity. On the other hand, if the melting temperature is increased, if the retention time at the melting temperature is increased, or if the cooling rate during casting is slow, coarse oxides or carbides may increase. Therefore, from the viewpoint of improving press punchability by reducing the precipitation of coarse oxides and carbides and dispersing the oxides and carbides with high uniformity, the melting temperature in the casting process [step 1] and the melting temperature The holding time in and the cooling rate during casting are preferably within the above ranges. In particular, the retention time at the melting temperature is more preferably within 1 hour.

(ii) Homogenization heat treatment step [step 2]
The homogenization heat treatment step [step 2] is a step of subjecting the ingot after the casting step [step 1] to a heat treatment for homogenization. Here, the heat treatment conditions in the homogenization heat treatment step [step 2] are such that the heating temperature is in the range of 750 ° C. or higher and 900 ° C. or lower and the holding time at the heating temperature is 10 from the viewpoint of suppressing the coarsening of the crystal grains. It is preferable to set the time in the range of 1 minute to 10 hours.

(iii) hot working step [step 3]
In the hot working process [Step 3], the ingot that has been subjected to the homogenization heat treatment is subjected to stretching such as hot rolling and wire drawing until it reaches a predetermined thickness and size, and the hot worked material is obtained. This is the manufacturing process. Here, the hot working step [step 3] includes both the hot rolling step and the hot drawing (wire drawing) step. As for the conditions of the hot working step [step 3], the working temperature is preferably in the range of 750° C. or higher and 900° C. or lower, and may be the same as the heating temperature in the homogenization heat treatment step [step 2]. Moreover, the working rate in the hot working step [Step 3] is preferably 10% or more.

Here, the "processing rate" is the value obtained by subtracting the cross-sectional area after processing from the cross-sectional area before stretching such as rolling or wire drawing, dividing the value by the cross-sectional area before processing, multiplying by 100, and percent is a value expressed by the following formula.
[Processing rate] = {([cross-sectional area before processing] - [cross-sectional area after processing]) / [cross-sectional area before processing]} x 100 (%)

It is preferable to cool the hot-worked material after the hot working step [Step 3]. Here, the means for cooling the hot-worked material is not particularly limited, but from the viewpoint of making coarsening of crystal grains difficult to occur, it is preferable to use a means for increasing the cooling rate as much as possible, such as water cooling. It is preferable to set the cooling rate to 10° C./second or more by means of .

Here, the surface of the hot-worked material after cooling may be chamfered. Chamfering can remove surface oxide films and defects generated in the hot working step [step 3]. The conditions for facing are not particularly limited as long as they are the conditions that are commonly used. The amount to be removed from the surface of the hot-worked material by chamfering can be appropriately adjusted based on the conditions of the hot-working step [Step 3], for example, about 0.5 to 4 mm from the surface of the hot-worked material. be able to.

(v) First cold working step [Step 4]
In the first cold working step [step 4], the hot worked material after the hot working step [step 3] is cold rolled at an arbitrary working rate according to the thickness and size of the product. It is a process of applying drawing processing such as wire drawing. Here, the first cold working step [Step 4] includes both the cold rolling step and the cold drawing (wire drawing) step. The conditions for stretching such as rolling and wire drawing in the first cold working step [step 4] can be set according to the size of the hot-worked material. In particular, in the first annealing step [step 5] described later, from the viewpoint of promoting uniform precipitation of crystal grains by recrystallization, the total working rate in the first cold working step [step 4] may be 50% or more. preferable.

(vi) First annealing step [Step 5]
The first annealing step [step 5] is an annealing step in which the cold-rolled material after the first cold working step [step 4] is heat-treated and recrystallized. Here, the heat treatment conditions in the first annealing step [step 5] are such that the heating temperature is in the range of 600° C. or higher and 800° C. or lower, and the holding time at the heating temperature is in the range of 1 minute or longer and 2 hours or shorter. On the other hand, when the heating temperature is less than 600° C. or when the holding time is less than 1 minute, it becomes difficult to recrystallize the copper alloy material. In addition, when the heating temperature exceeds 800° C. or when the holding time exceeds 2 hours, crystal grains may become coarse, resulting in poor workability.

Here, it is preferable to repeatedly perform the cold working step and the annealing step once or more on the cold-rolled material that has undergone the first annealing step [step 5]. For example, the cold-rolled material after the first annealing step [step 5] may be subjected to a second cold working step and annealing step. A second cold working step [step 6] and a second annealing step [step 7] can be performed, respectively. By repeating the cold working process and the annealing process one or more times in this manner, the copper alloy material becomes a plate material, bar material, strip material, or wire material having a desired shape, and coarse crystal grains are less likely to be formed. Therefore, it is possible to obtain a copper alloy material exhibiting desired characteristics in terms of workability, volume resistivity, and copper thermoelectromotive force.

At this time, the total working rate in the second cold working process [Step 6] can be 50% or more. The heat treatment conditions in the second annealing step [Step 7] are such that the heating temperature is in the range of 600° C. or more and 800° C. or less, and the holding time at the heating temperature is in the range of 1 minute or more and 2 hours or less.

[4] Uses of copper alloy material The copper alloy material of the present invention is extremely useful as a resistance material for resistors used in resistors such as shunt resistors or chip resistors. That is, it is preferable that the resistive material for a resistor is made of the copper alloy material described above. Also, resistors such as shunt resistors or chip resistors preferably have a resistive material for resistors made of the copper alloy material described above.

Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and includes various aspects within the scope of the present invention, including all aspects included in the concept of the present invention and the scope of claims. can be modified to

Next, in order to further clarify the effects of the present invention, examples of the present invention and comparative examples will be described, but the present invention is not limited to these examples.

(Invention Examples 1 to 17 and Comparative Examples 1 to 6)
As a copper-based material, copper, manganese, nickel, graphite, copper oxide and optional additive components are blended according to the alloy composition ratio shown in Table 1, melted in a high-frequency melting furnace in a non-oxidizing atmosphere, and melted from the melt. A casting step [Step 1] of cooling to 600° C. and casting was performed to obtain an ingot. Here, among the components listed in Table 1, the optionally added components marked with a horizontal line "-" are not added as raw materials to the copper-based material. Table 1 shows the temperature for melting the copper-based material (melting temperature), the holding time at the melting temperature, and the cooling rate of the molten metal after the holding time.

This ingot is subjected to a homogenization heat treatment step [Step 2] in which heat treatment is performed at a heating temperature of 800 ° C. and a holding time of 5 hours. A hot-worked material was obtained by performing a hot-working step [Step 3] of rolling along the longitudinal direction so that the thickness before working was 30 mm and the thickness after working was 10 mm. After that, the substrate was cooled to room temperature by water cooling, and was chamfered to remove the oxide film formed on the surface. The thickness of the hot worked material after facing was 8 mm.

After the hot working step [Step 3], the hot-worked material is rolled along the longitudinal direction at a total working rate of 88% (thickness before working is 8 mm, thickness after working is 1 mm). A cold working step [step 4] was performed. Next, the cold-rolled material after the first cold working step [step 4] is heat-treated at a heating temperature of 600° C. or higher and 800° C. or lower for a holding time in the range of 1 minute or more and 2 hours or less. The first annealing step [step 5] was performed.

Furthermore, for the hot-worked material after performing the first annealing step [step 5], in the longitudinal direction at a total working rate of 70% (thickness before working is 1 mm, thickness after working is 0.3 mm) A second cold working step [step 6] was carried out, rolling along. Next, the cold-rolled material after the second cold working step [step 6] is heat-treated at a heating temperature of 600° C. or higher and 800° C. or lower for a holding time in the range of 1 minute or more and 2 hours or less. The second annealing step [step 7] was performed. In this manner, copper alloy sheet materials of Inventive Examples 1 to 17 and Comparative Examples 1 to 6 were produced.

In Table 1, a horizontal line "-" is written in the column of the component not included in the alloy composition of the copper-based material, and the corresponding component is not included, or even if it is included, it is less than the detection limit value. clarified.

[Various measurement and evaluation methods]
Using the copper alloy materials (copper alloy sheet materials) according to the examples of the present invention and the comparative examples, the following characteristics were evaluated. Evaluation conditions for each property are as follows.

[1] Measurement of the number of coarse precipitated particles containing oxides or carbides After preparing the sample, the cross section perpendicular to the stretching direction was polished. Next, the cross section of the test material after polishing is observed using an optical microscope (manufactured by Olympus, model number: GX71) with a 100 μm × 100 μm square as one field of view, and the oxides and carbides that appear black in the microscope image. Of the precipitated particles containing at least one of the above, coarse precipitated particles, which are precipitated particles with a maximum dimension of more than 20 µm, were counted. In the present invention example and the comparative example, after observing the cross section of the test material after polishing, the cross section perpendicular to the stretching direction of the test material was further polished, and the cross section of the test material at different positions in the stretching direction was measured. By repeating exposing and counting the coarse precipitated particles in the cross section in the same manner, the average value of the number of coarse precipitated particles in 5 fields of view was obtained, and the obtained average value was taken as the number of coarse precipitated particles. Table 2 shows the results.

[2] Evaluation method for press punchability The press punchability of the produced copper alloy material is described in the shear test method for copper and copper alloy thin strips specified in the Japan Copper and Brass Association Technical Standard JCBA T310: 2019. A shear test was performed. That is, for the copper alloy material, the clearance between the upper die (punch) and the lower die (die) is adjusted to 10 μm, and the size along the stretching direction y is 2 mm, and the width is perpendicular to the stretching direction y. A rectangular shape with a size of 10 mm was punched along the direction (x direction in FIG. 1) intersecting with , and a test material of a copper alloy material 1 having a cut surface 2 on the outer periphery was produced.

FIG. 1 is a schematic diagram showing a cut surface when press punching is performed on the copper alloy material of the present invention. A copper alloy material 1 shown in FIG. 1 shows a cut surface 2 after being subjected to press punching, which is performed by lowering an upper die (punch) while being fixed on a lower die (not shown). be. Here, on the cut surface 2, a droop 3, a sheared surface 4 and a fractured surface 5 are formed in order from the upper surface 1a side of the copper alloy material 1 punched by press. Moreover, burrs 6 are often formed on the lower edge of the cut surface 2 so as to extend outward from the fractured surface 5 . Therefore, the cross section including the thickness direction and the width direction of the copper alloy material 1 includes the sag 3 , the sheared surface 4 , the fractured surface 5 and the burr 6 .

In this embodiment, of the formed cut surface 2, a section including the thickness direction z and the width direction x, which is a surface along the direction perpendicular to the stretching direction y, is scanned with a scanning electron microscope (SEM ) (SSX-550 manufactured by Shimadzu Corporation) was used for observation at a magnification of 200 times. Then, from a scanning electron microscope (SEM) photograph of the cut surface 2, the ratio of the cross-sectional area of the sheared surface 4 to the cross-sectional area of the cross section including the thickness direction and the width direction was calculated.

If the ratio of the cross-sectional area of the sheared surface 4 to the calculated cross-sectional area including the thickness direction and the width direction is 40% or more, it is evaluated as excellent in press punching workability. did. In addition, when the ratio of the cross-sectional area of the shear surface 4 to the cross-sectional area including the thickness direction and the width direction is 35% or more and less than 40%, it is considered that the press punchability is good. evaluated. On the other hand, when this ratio was less than 35%, it was evaluated as "x" because the press punchability was poor. Table 2 shows the results.

[3] Measurement of Volume Resistivity Regarding the produced copper alloy material, the obtained plate material with a thickness of 0.3 mm was cut into a width of 10 mm and a length of 300 mm to produce a test material.

The volume resistivity ρ is measured by setting the distance between the voltage terminals to 200 mm, the measurement current to 100 mA, and measuring the voltage at room temperature of 20°C by the four-terminal method according to the method specified in JIS C2525. A volume resistivity ρ [μΩ·cm] was obtained.

Regarding the measured volume resistivity ρ, when the volume resistivity ρ was 80 μΩ·cm or more, the volume resistivity ρ was sufficiently large, and it was evaluated as "◎" as being excellent as a resistive material. In addition, when the volume resistivity ρ was 70 μΩ·cm or more and less than 80 μΩ·cm, the volume resistivity ρ was large and was evaluated as “good” as a good resistance material. On the other hand, when the volume resistivity ρ was less than 70 μΩ·cm, the volume resistivity ρ was small, and it was evaluated as “×” as a poor resistance material. In this example, "⊚" and "◯" were evaluated as pass levels. Table 2 shows the results.

[4] Measurement method of copper thermoelectromotive force (EMF) For the produced copper alloy material, the obtained plate material with a thickness of 0.3 mm was cut into a width of 10 mm and a length of 1000 mm to produce a test material.

The measurement of the copper thermoelectromotive force (EMF) of the test material was performed according to JIS C2527. More specifically, as shown in FIG. The temperature measuring junction _P1 , to which one end of the test material 11 and standard copper wire 21 is connected, is immersed in hot water kept warm in a constant temperature bath 41 at 80 ° C., and the test material 11 and The electromotive force when the reference contacts _P21 and _P22 , in which the other ends of the standard copper wire 21 are connected to the

copper wires

31 and 32, respectively, are immersed in 0°C ice water insulated by the freezing point device 42 is , was measured by the voltage measuring device 43 . By dividing the obtained electromotive force by 80 [° C.], which is the temperature difference, the thermoelectromotive force EMF (μV/° C.) against copper was obtained.

Regarding the measured thermoelectromotive force against copper (EMF), when the absolute value is 0.6 μV / ° C. or less, the absolute value of the thermoelectromotive force against copper (EMF) is small and it is considered to be good as a resistive material. 0” was evaluated. On the other hand, when the absolute value of the thermoelectromotive force (EMF) to copper is greater than 0.6 μV/° C., the absolute value of the thermoelectromotive force (EMF) to copper is large, and it is regarded as being unsatisfactory as a resistive material, and is marked as “x”. evaluated. Table 2 shows the results.

[5] Comprehensive evaluation Of the three evaluation results regarding press punchability, volume resistivity ρ, and copper thermoelectromotive force (EMF), both the evaluation results of press punchability and volume resistivity ρ were given “◎”. When evaluated and the copper thermoelectromotive force (EMF) is evaluated as “○”, the three characteristics of press punchability, volume resistivity ρ and copper thermoelectromotive force (EMF) are considered to be excellent. ◎”. In addition, among these three evaluation results, one or both of the evaluation results of press punchability and volume resistivity ρ, and the copper thermoelectromotive force (EMF) are evaluated as "○", and the rest are evaluated as "◎". When evaluated as "A", these three characteristics were evaluated as "good" at least. On the other hand, when at least one of press punching workability, volume resistivity ρ, and copper thermoelectromotive force (EMF) is evaluated as “×”, at least one of these three characteristics is evaluated. It was evaluated as "×" as being unacceptable. Table 2 shows the results.

From the results in Tables 1 and 2, the copper alloy materials of Examples 1 to 17 of the present invention have an alloy composition within the appropriate range of the present invention, and when viewed in a cross section perpendicular to the stretching direction, oxide and the number of coarse precipitated particles containing at least one of carbide and carbide was 3 or less in each case. there were. In addition, the copper alloy materials of Examples 1 to 17 of the present invention were all evaluated as "good" with respect to copper thermoelectromotive force (EMF).

On the other hand, the copper alloy material of Comparative Example 1 had a small total amount of O and C, and the alloy composition was outside the proper range of the present invention. Therefore, the copper alloy material of Comparative Example 1 was evaluated as "poor" in press punching workability.

Also, the copper alloy material of Comparative Example 2 had a large total amount of O and C, which was outside the appropriate range of the present invention. Therefore, the copper alloy material of Comparative Example 2 was cracked during rolling in the hot working process [process 3].

In addition, the copper alloy material of Comparative Example 3 had a low Mn content, and the alloy composition was outside the appropriate range of the present invention. Therefore, the copper alloy material of Comparative Example 3 was evaluated as "x" in volume resistivity ρ.

In addition, the copper alloy material of Comparative Example 4 had a large Mn content, and the alloy composition was outside the appropriate range of the present invention. Therefore, the copper alloy material of Comparative Example 4 was evaluated as "x" in terms of copper thermoelectromotive force (EMF).

In addition, the copper alloy material of Comparative Example 5 had a large Ni content, and the alloy composition was outside the appropriate range of the present invention. Therefore, the copper alloy material of Comparative Example 5 was evaluated as "x" in terms of copper thermoelectromotive force (EMF).

In addition, the copper alloy material of Comparative Example 6 had a low Ni content, and the alloy composition was outside the appropriate range of the present invention. Therefore, the copper alloy material of Comparative Example 6 was evaluated as "x" in terms of copper thermoelectromotive force (EMF).

From this result, it was confirmed that the copper alloy material of the present invention example has at least good volume resistivity ρ and copper thermoelectromotive force (EMF) when the alloy composition is within the proper range of the present invention. . At the same time, it was confirmed that the copper alloy material of the example of the present invention has at least good press-punching workability.

FIG. 3 shows an example of an optical microscope photograph of a cross section perpendicular to the stretching direction during working of the copper alloy material of Inventive Example 9, observed within a viewing area of 10000 μm ² . In this optical micrograph, precipitated particles containing oxides and/or carbides appear as black dots. From the optical micrograph of FIG. 3, it was confirmed that coarse precipitated particles, which are precipitated particles having a maximum dimension of more than 20 μm, were not precipitated within the field of view as precipitated particles containing at least one of oxides and carbides. .

4 and 5 show the cross sections including the thickness direction and the width direction of the cut surfaces of the copper alloy materials of the present invention example and the comparative example when the press punching process is performed using a scanning electron microscope. (SEM) Photographs are shown. Here, FIG. 4 is a SEM photograph of a cut surface when the copper alloy material of Example 11 of the present invention was punched by press, and FIG. 5 is a photograph of the cut surface when the copper alloy material of Comparative Example 1 was punched by press. It is an SEM photograph of a cut surface when the film is cut. 4 and 5, the boundary between the sheared surface 4, 400 and the fractured surface 5, 500 is indicated by a dashed line. From these SEM photographs, the ratio of the cross-sectional area of the shear plane 4 to the cross-sectional area of the cross section including the thickness direction and the width direction of the copper alloy material 1 of the example of the present invention is 400 It was confirmed that it is larger than the ratio of the cross-sectional area of

1 Copper alloy material 1a Upper surface of copper alloy material 1b Lower surface of copper alloy material 2, 200 Cut surface 3, 300 Sagging 4, 400 Shear surface 5, 500 Fracture surface 6, 600 Burr 7 Boundary line 10 Copper thermoelectromotive force (EMF ) Measuring device 11 Sample material 21

Standard copper wire

31, 32 Copper wire 41 Thermostatic bath 42 Freezing point device 43 Voltage measuring device 100 Copper alloy material of comparative example 100a Upper surface of copper alloy material of comparative example 100b Copper alloy material of comparative example Lower surface _P1 temperature measuring junction _P21 , _P22 reference junction x width direction y stretching direction z thickness direction

Claims

Mn: 20.0% by mass or more and 35.0% by mass or less and Ni: 6.5% by mass or more and 17.0% by mass or less,
O: 0 mass ppm or more and 800 mass ppm or less and C: 0 mass ppm or more and 800 mass ppm or less and an alloy containing 60 mass ppm or more and 800 mass ppm or less in total of O and C, and the balance being Cu and inevitable impurities A copper alloy material having a composition.
Among the precipitated particles containing at least one of oxides and carbides observed in a viewing area of 10000 μm 2 when viewed in a cross section perpendicular to the stretching direction during processing of the copper alloy material, the maximum dimension is 20 μm. 2. The copper alloy material according to claim 1, wherein the number of coarse precipitated particles, which are super precipitated particles, is 3 or less.
The alloy composition is
Fe: 0.01% by mass or more and 0.50% by mass or less,
Co: 0.01% by mass or more and 2.00% by mass or less,
Sn: 0.01% by mass or more and 5.00% by mass or less,
Zn: 0.01% by mass or more and 5.00% by mass or less,
Cr: 0.01% by mass or more and 0.50% by mass or less,
Ag: 0.01% by mass or more and 0.50% by mass or less,
Al: 0.01% by mass or more and 1.00% by mass or less,
Mg: 0.01% by mass or more and 0.50% by mass or less,
Si: 0.01% by mass or more and 0.50% by mass or less, and P: 0.01% by mass or more and 0.50% by mass or less. The copper alloy material according to .
A resistance material for a resistor, comprising the copper alloy material according to any one of claims 1 to 3.
A resistor comprising the resistance material for a resistor according to claim 4.