JP4623737B2 - High-strength and highly conductive two-phase copper alloy - Google Patents

Description

本発明は強度と導電性に優れ、例えば電子機器用のばね材や箔材に好適に適用できる二相銅合金に関する。   The present invention relates to a two-phase copper alloy that is excellent in strength and conductivity and can be suitably applied to, for example, a spring material or a foil material for electronic equipment.

端子、コネクタ、スイッチ，リレー等の電気・電子機器用のばね材（コネクタ用材）には優れたばね特性、曲げ性、導電性が要求され、従来からりん青銅等が用いられてきたが、近年では電子部品の一層の小型化の要請から高強度高導電性の合金が開発されている。
一般に、Cuに強化元素を添加して高強度化すると導電率が低下し、一方で導電率を上昇させるためCu純度を高めると低強度となる関係がある。そこで、Cu母相中に第二相を晶出させた合金系（複相合金）が開発された。この合金は、強加工することにより第二相がファイバ状に分散され、りん青銅と同等の強度を持ちつつ、母相はCuであるため、導電率が60%IACS（international annealed copper standard、焼鈍標準軟銅に対する電気伝導度の比）を超える高導電性材が得られている。この複相合金系としては、Cu-Cr、Cu-Fe、Cu-Nb、Cu-W、Cu-Ta、Cu-Agなどが知られている（例えば、特許文献１〜７参照）。 Spring materials (connector materials) for electrical and electronic equipment such as terminals, connectors, switches, and relays are required to have excellent spring characteristics, bendability, and conductivity. Conventionally, phosphor bronze has been used. High-strength, high-conductivity alloys have been developed in response to demands for further miniaturization of electronic components.
In general, when a strengthening element is added to Cu to increase the strength, the electrical conductivity decreases, while on the other hand, increasing the Cu purity has a relationship of decreasing the strength to increase the electrical conductivity. Therefore, an alloy system (double phase alloy) was developed in which the second phase was crystallized in the Cu matrix. This alloy has a second phase dispersed in a fiber form by strong processing and has the same strength as phosphor bronze, but the parent phase is Cu, so the conductivity is 60% IACS (international annealed copper standard, annealed) A highly conductive material exceeding the ratio of electrical conductivity to standard annealed copper has been obtained. As this multiphase alloy system, Cu—Cr, Cu—Fe, Cu—Nb, Cu—W, Cu—Ta, Cu—Ag and the like are known (for example, see Patent Documents 1 to 7).

特開平9-249925号公報JP-A-9-249925 特開平10-140267号公報Japanese Patent Laid-Open No. 10-140267 特開平10-8166号公報Japanese Patent Laid-Open No. 10-8166 特開平06-192801号公報Japanese Patent Laid-Open No. 06-192801 特開平06-279894号公報Japanese Patent Laid-Open No. 06-279894 特開平10-53824号公報Japanese Patent Laid-Open No. 10-53824 特開平10-349085号公報Japanese Patent Laid-Open No. 10-349085

ところで、上記従来技術の場合、第二相をファイバ状に延伸するための強加工法として、線引き、圧延等の手段が用いられる。この場合、線材であれば、そもそも線方向の強度しか要求されないので、線引きして第二相を延伸するだけで充分な強度が確保される。
また、特許文献４〜７記載の技術は、上記複相合金により圧延材を製造したものであり、第二相が圧延方向に充分延伸されて繊維状になると、圧延直角方向（圧延材の長手方向に圧延が進むとして、圧延材の幅方向をいう）の強度も向上することが記載されている。 By the way, in the case of the said prior art, means, such as drawing and rolling, are used as a strong processing method for extending | stretching a 2nd phase to a fiber form. In this case, since the wire is only required to have a strength in the wire direction, sufficient strength can be ensured only by drawing and stretching the second phase.
In addition, the techniques described in Patent Documents 4 to 7 are produced by producing a rolled material from the above-described multiphase alloy. When the second phase is sufficiently stretched in the rolling direction to become fibrous, the direction perpendicular to the rolling direction (the length of the rolled material) It is described that as the rolling proceeds in the direction, the strength of the rolled material is also improved.

しかしながら、これら文献には、曲げ加工性について記載はない。例えば、コネクタを上記圧延材から採取する場合、コネクタの並ぶ方向を圧延材の長手方向とし、各ピンが圧延材の幅方向に延びるようにしてコネクタを打抜くのが通例であるが、上記圧延直角方向に曲げる場合には、この方向の曲げ加工性が低いと、コネクタへ曲げ加工する際、クラックが発生することがある。このような複相合金での問題は、本発明者らが初めて着目したものであり、従来の複相合金について本発明者らが圧延直角方向の曲げ加工性を調査した結果、曲げ加工性が非常に悪いことが判明した。
特に，第二相を微細に分散させて強度を高くするには強加工が必要となるが，強加工を行うほど曲げ加工性は低下する。また，曲げ加工性を確保するために焼鈍を行うと，繊維状組織が球状化してしまい，強度が低下する。したがって，強度と曲げ加工性の両立は従来困難であった。
本発明は上記の課題を解決するためになされたものであり、材料強度の異方性が低減され、曲げ加工性に優れた高強度高導電性二相銅合金の提供を目的とする。 However, these documents do not describe bending workability. For example, when a connector is taken from the rolled material, it is customary to punch the connector in such a way that the connector is aligned in the longitudinal direction of the rolled material and each pin extends in the width direction of the rolled material. When bending in a perpendicular direction, if the bending workability in this direction is low, cracks may occur when bending the connector. The problem with such a multi-phase alloy is what the present inventors have paid attention to for the first time, and as a result of investigating the bending workability in the direction perpendicular to the rolling of the conventional multi-phase alloy, the bending workability is It turned out to be very bad.
In particular, strong processing is required to increase the strength by finely dispersing the second phase, but bending workability decreases as the strength is increased. In addition, when annealing is performed to ensure bending workability, the fibrous structure is spheroidized and the strength is reduced. Therefore, it has been difficult to achieve both strength and bending workability.
The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a high-strength, high-conductivity, two-phase copper alloy with reduced material strength anisotropy and excellent bending workability.

本発明者らは種々検討した結果、Cu母相中に第二相を晶出させた合金系（以下、「複相合金」と称する）の圧延材において、圧延直角断面から見たとき、第二相の厚み及びその間隔を小さくし、さらに第二相の平均アスペクト比を規定することで、この方向の強度が向上し、曲げ加工性も改善されることを突き止めた。ここで、第二相のアスペクト比は、（第二相の伸長長さ）／（第二相の圧延厚み方向での厚さ）で表される。
圧延直角断面から見たときに圧延直角方向に第二相を延伸させる方法としては、例えば、圧延時の圧延張力を低くする、延伸後に圧延や熱処理を行わない、等が挙げられる。又、逆に圧延張力を高くし、伸び過ぎた第二相を分断させることによりアスペクト比が低減するので、結果としてアスペクト比を調整できる。 As a result of various studies, the present inventors have found that in a rolled material of an alloy system in which a second phase is crystallized in a Cu matrix (hereinafter referred to as “double phase alloy”), It was found that the strength in this direction was improved and the bending workability was improved by reducing the thickness of the two phases and the interval between them and further defining the average aspect ratio of the second phase. Here, the aspect ratio of the second phase is expressed by (extension length of the second phase) / (thickness of the second phase in the rolling thickness direction).
Examples of the method of stretching the second phase in the direction perpendicular to the rolling when viewed from the cross section perpendicular to the rolling include lowering the rolling tension during rolling, and not performing rolling or heat treatment after stretching. On the other hand, the aspect ratio is reduced by increasing the rolling tension and separating the excessively extended second phase. As a result, the aspect ratio can be adjusted.

上記の目的を達成するために、本発明の高強度高導電性二相銅合金は、質量％でFeを7％以上20％以下含有すると共にMg,Ag,Sn及びZrの群から選ばれる１種又は２種以上を合計で0.01％以上1％以下含有し残部Cu及び不可避的不純物からなり、Cu母相と第二相とからなる0.2％耐力が750MPa以上の圧延材であって、圧延直角断面から見たとき、前記第二相の厚み及び圧延面方向に隣接する第二相の間隔が3μｍ以下であり、かつ前記第二相の平均アスペクト比Ａｔが10≦Ａｔ≦80である。 In order to achieve the above object, the high-strength and highly-conductive two-phase copper alloy of the present invention contains 7% to 20% by mass of Fe and is selected from the group consisting of Mg, Ag, Sn and Zr. A rolling material with a total of 0.01% or more and 1% or less of seeds or two or more types, the balance being Cu and inevitable impurities, and a 0.2% proof stress consisting of a Cu matrix and a second phase of 750 MPa or more. When viewed from the cross section, the thickness of the second phase and the interval between the second phases adjacent in the rolling surface direction are 3 μm or less, and the average aspect ratio At of the second phase is 10 ≦ At ≦ 80.

前記第二相を前記圧延直角断面から見たときの平均アスペクト比Ａｔと、前記第二相を圧延平行断面から見たときの平均アスペクト比ＡＬとが、ＡＬ/Ａｔ<20の関係を満たすことが好ましい。   The average aspect ratio At when the second phase is viewed from the cross section perpendicular to the rolling and the average aspect ratio AL when the second phase is viewed from the cross section parallel to the rolling satisfy the relationship AL / At <20. Is preferred.

本発明によれば、材料強度の異方性が低減され、曲げ加工性に優れた高強度高導電性二相銅合金が得られる。   According to the present invention, anisotropy of material strength is reduced, and a high-strength and highly conductive two-phase copper alloy excellent in bending workability can be obtained.

以下、本発明に係る高強度高導電性二相銅合金の実施の形態について説明する。なお、本発明において％とは、特に断らない限り、質量％を示すものとする。   Embodiments of the high-strength, high-conductivity two-phase copper alloy according to the present invention will be described below. In the present invention, “%” means “% by mass” unless otherwise specified.

［化学成分］
化学成分として、上記銅合金はFeを7％以上20％以下含有する。Feが７％以上含有されるとCu母相中に第二相として晶出し、いわゆる「複相合金」を構成する。Fe含有量が７％未満であると、第二相による複合強化の効果が少ない。Fe含有量が２０％を超えると融点が上昇すると共に固液共存温度域が大きくなり、鋳造等が困難になって生産性が低下したり，得られた合金の導電性が低下する。
上記銅合金中の不可避的不純物の含有量は、ＪＩＳに規格する無酸素銅と同一であるのが好ましい。例えば、ＪＩＳ Ｈ ２１２３に規格する無酸素形銅C1011における、不純物の含有量と同等にすることができる。 [Chemical composition]
As a chemical component, the copper alloy contains 7% to 20% of Fe. When Fe is contained in an amount of 7% or more, it is crystallized as a second phase in the Cu matrix and constitutes a so-called “multiphase alloy”. When the Fe content is less than 7%, the effect of composite strengthening by the second phase is small. If the Fe content exceeds 20%, the melting point increases and the solid-liquid coexistence temperature range increases, casting becomes difficult and productivity decreases, and the conductivity of the obtained alloy decreases.
The content of inevitable impurities in the copper alloy is preferably the same as oxygen-free copper specified in JIS. For example, it can be made equivalent to the content of impurities in oxygen-free copper C1011 standardized to JIS H2123.

［第二相］
第二相は、Cu及び上記化学成分を含む合金溶湯から鋳造時に上記元素が晶出したものであり、晶出の際、第二相にFeが多く分配される。通常、第二相中のFe濃度は９０％以上である。又、第二相は，Ｃｕ母相内に例えば針状に晶出するが，晶出形態はこれに限定されない。第二相は、最終工程終了後の圧延組織の断面を研磨した後、ＳＥＭ（走査型電子顕微鏡）のＢＳＥ（反射電子）像により、母相と異なる組成として観察することができる。組織が観察しにくい場合は、エッチング又は電解研磨を行ってもよい。 [Second phase]
In the second phase, the element is crystallized at the time of casting from a molten alloy containing Cu and the chemical component, and a large amount of Fe is distributed to the second phase during the crystallization. Usually, the Fe concentration in the second phase is 90% or more. The second phase is crystallized, for example, in a needle shape in the Cu matrix, but the crystallization form is not limited to this. The second phase can be observed as a composition different from the parent phase by a BSE (backscattered electron) image of an SEM (scanning electron microscope) after polishing the cross section of the rolled structure after the final step. If the structure is difficult to observe, etching or electropolishing may be performed.

［添加元素］
上記銅合金は、さらにMg,Ag,Sn及びZrの群から選ばれる１種又は２種以上の添加元素を合計で0.01％以上1％以下含有する。添加元素を含有することにより、0.2％耐力が750MPa以上の銅合金が得られる。
詳しくは後述するが、複相合金を強化するためには，第二相の初期晶出物を微細とさせ、さらにその後の加工により第二相を変形させて互いに近接させることが重要であり、そのため第二相が変形し易いことが必要である。しかしながら、複相合金系を析出硬化させるために添加元素を添加すると、添加元素が第二相に分配され（第二相中の添加元素の濃度が高くなり）、第二相が粗大な晶出物となる場合がある等の理由から、第二相が変形し難くなる。その結果、加工により第二相が充分に引き伸ばされず母相中に粗大な介在物が存在するのと同様なこととなり、Ｃｕ母相と第二相の界面の面積が減少する。このような組織は、かえって強度低下を招くとともに、ばね材用に要求される曲げ加工性及び、圧延箔に要求される屈曲性等をも低下させる。 [Additive elements]
The copper alloy further contains one or more additive elements selected from the group consisting of Mg, Ag, Sn, and Zr in a total of 0.01% to 1%. By containing the additive element, a copper alloy having a 0.2% proof stress of 750 MPa or more can be obtained.
As will be described in detail later, in order to reinforce the multiphase alloy, it is important to make the initial crystallized product of the second phase fine and further deform the second phase by subsequent processing to bring them close to each other. Therefore, it is necessary for the second phase to be easily deformed. However, when an additive element is added to precipitate and harden the multiphase alloy system, the additive element is distributed to the second phase (the concentration of the additive element in the second phase increases), and the second phase is coarsely crystallized. For reasons such as becoming a product, the second phase is hardly deformed. As a result, the second phase is not sufficiently stretched due to processing, and coarse inclusions are present in the parent phase, and the area of the interface between the Cu parent phase and the second phase is reduced. Such a structure, on the contrary, causes a decrease in strength, and also reduces the bending workability required for the spring material, the flexibility required for the rolled foil, and the like.

そこで、本発明においては、Ｃｕ母相に多く分配される添加元素を選択することにより、上記した問題を解消し、析出硬化等により母相を強化することができる。また，添加元素がＣｕ母相に分配されると、銅母相が強化されることに伴って第二相の延伸が容易になるという効果もある。さらに、第二相中の添加元素の含有割合の最大値を0.5％以下とすることにより，第二相の変形を容易にすることができる。
添加元素の含有量の合計が0.01％未満であると上記した効果が生じない。含有量が1％を超えると、添加元素が粗大な晶出物となり、曲げ加工性や屈曲性等の加工性、及び導電率が劣化すると共に、ピンホール等の欠陥となる。 Therefore, in the present invention, by selecting an additive element distributed in a large amount in the Cu matrix, the above problems can be solved and the matrix can be strengthened by precipitation hardening or the like. Further, when the additive element is distributed to the Cu matrix, there is an effect that the extension of the second phase is facilitated as the copper matrix is strengthened. Furthermore, the deformation of the second phase can be facilitated by setting the maximum content ratio of the additive element in the second phase to 0.5% or less.
If the total content of the additive elements is less than 0.01%, the above-described effect does not occur. When the content exceeds 1%, the additive element becomes a coarse crystallized product, and the workability such as bendability and bendability and the conductivity are deteriorated, and defects such as pinholes are caused.

第二相中の添加元素の含有割合は、例えば得られた材料の表面又は断面をオージェ電子分光分析法（AES:Auger Electron Spectroscopy）により分析し、元素定量を行うことで求めることができる。第二相がある程度大きさを有する間（例えば、鋳造後の圧延初期等）に分析すれば、銅母相の影響を受けずに通常のオージェ分析が可能である。又、予め、各添加元素の純物質に対して検量線を作成しておき、定量を行えばよい。
なお、同一供試材においても、個々の晶出物によって添加元素の含有割合には、ばらつきがある。そこで、例えば１つの合金試料において50点（50の晶出物）に対し添加元素の含有割合を測定し，その最大値を第二相の添加元素の含有割合とすることができる。但し、第二相を形成する元素と添加元素とが特定の組成比で形成される金属間化合物の晶出物については、測定から除外する。例えば、第二相を形成する元素Ｆｅと添加元素とが形成する金属間化合物の組成比に近い値を示す晶出物は、Ｆｅと添加元素が形成する金属間化合物とみなし、測定から除外する。
又、第二相が二種以上の添加元素を含有している場合は、それら複数の添加元素の合計量を含有割合とする。 The content ratio of the additive element in the second phase can be determined, for example, by analyzing the surface or cross section of the obtained material by Auger Electron Spectroscopy (AES) and performing element quantification. If the analysis is performed while the second phase has a certain size (for example, the initial stage of rolling after casting), normal Auger analysis is possible without being affected by the copper matrix phase. In addition, a calibration curve may be prepared in advance for the pure substance of each additive element and quantified.
Even in the same specimen, the content ratio of the additive element varies depending on the individual crystallized substances. Therefore, for example, the content ratio of the additive element can be measured for 50 points (50 crystallized products) in one alloy sample, and the maximum value can be set as the content ratio of the additive element of the second phase. However, the crystallization product of the intermetallic compound in which the element forming the second phase and the additive element are formed at a specific composition ratio is excluded from the measurement. For example, a crystallized product showing a value close to the composition ratio of the intermetallic compound formed by the element Fe forming the second phase and the additive element is regarded as an intermetallic compound formed by Fe and the additive element, and excluded from the measurement. .
Further, when the second phase contains two or more kinds of additive elements, the total amount of these additive elements is taken as the content ratio.

なお、上記分析は、合金の最終状態（圧延材、箔等）について行うのが好ましいが、最終組織は強加工によって第二相が引き伸ばされ薄くなり、分析が困難となるので、第二相が比較的厚い圧延面側から行うとよい。又、合金の最終状態でなく、強加工（圧延）の途中で分析してもよい。さらに、分析面を予め電解研磨してから分析すると好ましい。   The above analysis is preferably performed on the final state of the alloy (rolled material, foil, etc.), but the final structure is thinned because the second phase is stretched and thinned by strong processing. It is good to carry out from the relatively thick rolling surface side. Moreover, you may analyze not in the final state of an alloy but in the middle of strong processing (rolling). Furthermore, it is preferable to analyze after analyzing the analysis surface in advance.

［第二相における添加元素の含有量の調整方法］
第二相における添加元素の含有量を調整する方法として、鋳造条件，均質化条件，熱間圧延，鍛造条件を制御することが挙げられる。例えば、鋳造条件を制御することで添加元素の含有量を大きく変化させることができる。鋳造条件の制御とは、例えば鋳塊への冷却条件を調整し、冷却水量、凝固時の温度勾配、及び過冷度を制御したりして凝固速度を高くする（凝固を早くする）ようにする。又、電磁攪拌を併用することもある。具体的には、鋳塊の凝固速度は、鋳型の材質や厚みを変化させて冷却能を変化させたり、鋳型の寸法を変えたりすることで調整可能である。
又、添加元素毎に銅母相，第二相への固溶量が異なり，また合金系の組成によっても添加元素の固溶量が大きく変化する場合もある。このような場合、鋳造時の調整が困難であれば、添加元素の濃度の調整によって第二相への添加元素の含有量を調整する。 [Method for adjusting content of additive element in second phase]
As a method for adjusting the content of the additive element in the second phase, it is possible to control casting conditions, homogenization conditions, hot rolling, and forging conditions. For example, the content of the additive element can be greatly changed by controlling the casting conditions. The control of casting conditions is, for example, adjusting the cooling conditions for the ingot, and controlling the amount of cooling water, the temperature gradient during solidification, and the degree of supercooling to increase the solidification rate (fasten solidification). To do. Moreover, electromagnetic stirring may be used together. Specifically, the solidification speed of the ingot can be adjusted by changing the cooling capacity by changing the material and thickness of the mold or changing the dimensions of the mold.
In addition, the amount of solid solution in the copper matrix phase and the second phase differs for each additive element, and the amount of solid solution in the additive element may vary greatly depending on the alloy composition. In such a case, if adjustment during casting is difficult, the content of the additive element in the second phase is adjusted by adjusting the concentration of the additive element.

［第二相の平均アスペクト比Ａｔ］
本発明に係る合金は圧延材をなし、従来の伸線材と比べて第二相の形態に特徴がある。以下に述べるように、第二相をリボン状に分散させると、特に圧延材（ばね用材料、箔）を製造する場合に有利となる。
第二相をファイバ状に延伸するための強加工法として、線引き、圧延等の手段が用いられるが、線材であれば、そもそも線方向の強度しか要求されないので、線引きして第二相を延伸するだけで充分な強度が確保される。
一方、複相合金により圧延材を製造する際、第二相が圧延方向に充分延伸されて繊維状になると、圧延直角方向（圧延材の長手方向に圧延が進むとして、圧延材の幅方向をいう）の強度も向上する。しかしながら、コネクタを上記圧延材から採取する場合、コネクタの並ぶ方向を圧延材の長手方向とし、各ピンが圧延材の幅方向に延びるようにしてコネクタを打抜くのが通例であるが、上記圧延直角方向に曲げる場合には、この方向の曲げ加工性が低いと、コネクタへ曲げ加工する際、クラックが発生することがある。このような複相合金の圧延材の曲げ加工性については従来検討されていなかったが、本発明者らの調査により、従来は圧延直角方向の曲げ加工性が非常に悪いことが判明した。この対策として、第二相をリボン状に分散させることが、圧延直角方向の曲げ加工性の向上に有効であることがわかった。 [Average aspect ratio At of second phase At]
The alloy according to the present invention forms a rolled material and is characterized by a second phase form as compared with a conventional wire drawing material. As described below, when the second phase is dispersed in a ribbon shape, it is particularly advantageous when a rolled material (spring material, foil) is produced.
As a strong processing method for drawing the second phase into a fiber shape, means such as drawing and rolling are used. However, if a wire is used, only the strength in the line direction is required in the first place. Sufficient strength is ensured just by doing.
On the other hand, when a rolled material is produced from a multiphase alloy, if the second phase is sufficiently stretched in the rolling direction to become fibrous, the direction perpendicular to the rolling direction (the rolling proceeds in the longitudinal direction of the rolled material, the width direction of the rolled material is The strength of (say) also improves. However, when the connector is taken from the rolled material, the connector is typically punched so that the direction in which the connectors are arranged is the longitudinal direction of the rolled material and each pin extends in the width direction of the rolled material. When bending in a perpendicular direction, if the bending workability in this direction is low, cracks may occur when bending the connector. Conventionally, the bending workability of the rolled material of such a multiphase alloy has not been studied. However, the investigation by the present inventors has revealed that the bending workability in the direction perpendicular to the rolling is very poor. As a countermeasure, it has been found that dispersing the second phase in a ribbon shape is effective in improving the bending workability in the direction perpendicular to the rolling direction.

図１は、本発明の合金の圧延材組織を模式的に示したものである。この図において、圧延材組織は、Cu母相２のマトリクス中に第二相４が分散されている。そして、「板幅方向を「圧延直角方向Ｔ」とし、板の長手方向を「圧延平行方向Ｌ」とする。従来の複相合金の場合、第二相は圧延直角方向には殆ど延伸されずファイバ状である。一方、本発明においては、第二相は圧延直角方向にも延伸され、例えばリボン状（舌片状）の形態を示す。なお、従来から公知の他の複相合金において、圧延直角方向にも第二相が延伸されてリボン状（舌片状）になったものが存在する場合があっても、本発明においては、好ましくは第二相の圧延直角方向の長さは従来の複相合金より長い。   FIG. 1 schematically shows the rolled material structure of the alloy of the present invention. In this figure, in the rolled material structure, the second phase 4 is dispersed in the matrix of the Cu matrix 2. Then, “the width direction of the plate is defined as“ a perpendicular direction T of rolling ”and the longitudinal direction of the plate is defined as“ the parallel direction L of rolling ”. In the case of a conventional multiphase alloy, the second phase is hardly drawn in the direction perpendicular to the rolling and is in the form of a fiber. On the other hand, in the present invention, the second phase is also stretched in the direction perpendicular to the rolling direction, and shows, for example, a ribbon shape (tongue piece shape). In addition, in other conventionally known multi-phase alloys, even if there is a case where there is a ribbon-like (tongue piece-like) shape in which the second phase is stretched also in the direction perpendicular to the rolling direction, in the present invention, Preferably, the length of the second phase in the direction perpendicular to the rolling is longer than that of the conventional double phase alloy.

次に、アスペクト比について説明する。アスペクト比は、（第二相の伸長長さ）／（第二相の圧延厚み方向での厚さ）で定義される。従って、圧延直角方向に平行な断面（圧延直角断面）から見たアスペクト比Ａｔは、図１のｔ２／ｔ１、つまり（第二相の圧延直角方向への伸長長さ）／（第二相の圧延厚み方向（圧延面方向）での厚さ）で表される。同様に、圧延平行方向に沿う断面（圧延平行断面）から見たアスペクト比ＡＬは、図１のＬ２／Ｌ１で表される。ｔ２、ｔ１、Ｌ２、Ｌ１は第二相の断面像から求めることができる。通常、圧延直角断面についてＳＥＭのＢＳＥ像を得るが、それぞれの第二相におけるｔ２、ｔ１は、第二相の像におけるｔ２、ｔ１の最大値を採用すればよい。ＡＬについても同様である。
一つの第二相のｔ２、ｔ１から算出されるＡｔを複数個（たとえば１００個）の第二相について測定し、得られたＡｔの平均値を平均アスペクト比Ａｔとした。平均アスペクト比ＡＬも同様である。 Next, the aspect ratio will be described. The aspect ratio is defined by (extension length of the second phase) / (thickness in the rolling thickness direction of the second phase). Accordingly, the aspect ratio At viewed from a cross section parallel to the rolling perpendicular direction (rolling perpendicular cross section) is t2 / t1 in FIG. 1, that is, (extension length of the second phase in the perpendicular direction of rolling) / (second phase (Thickness in the rolling thickness direction (rolling surface direction)). Similarly, the aspect ratio AL viewed from a cross section along the rolling parallel direction (rolling parallel cross section) is represented by L2 / L1 in FIG. t2, t1, L2, and L1 can be obtained from a cross-sectional image of the second phase. Usually, an SEM BSE image is obtained for a rolling cross section, and the maximum values of t2 and t1 in the second phase image may be adopted as t2 and t1 in each second phase. The same applies to AL.
At calculated from t2 and t1 of one second phase was measured for a plurality of (for example, 100) second phases, and the average value of the obtained At was defined as the average aspect ratio At. The same applies to the average aspect ratio AL.

［Ａｔの規制範囲］
本実施形態において、Ａｔは１０〜８０とする。Ａｔが１０未満であると、圧延直角方向に第二相があまり延伸されず、この方向の複合強化が不充分となって強度が向上しない。一方、Ａｔが８０を超えるのは、製造上難しい。 [Regulation of At]
In this embodiment, At is set to 10-80. When At is less than 10, the second phase is not stretched so much in the direction perpendicular to the rolling direction, the composite reinforcement in this direction is insufficient, and the strength is not improved. On the other hand, it is difficult in manufacturing that At exceeds 80.

［Ａｔの調整方法］
通常，圧延を行うと厚さ方向には板厚が減少していく。本発明においては，添加元素及びその濃度を規定することによって鋳造組織は微細化しており，圧延加工度が高くなると，従来の複相合金よりも第２相の厚みが減少する割合が大きい。従って圧延直角方向のＡｔは，加工度が高くなるにつれ、同一加工度でも従来の複相合金よりも大きくなる。したがって板厚方向の強度は，従来の複相合金よりも高い。一方，圧延の加工度が大きくなるにつれて第二相は分断されやすくなるため，圧延後又は圧延後の熱処理によって第二相のＡｔが１０未満となる可能性がある。この場合は，圧延時の張力を調整することで剪断帯の発生を防ぐことにより，又は熱処理によって第二相を焼きなますことにより，十分な延性を確保する等によってＡｔの調整は可能である。
［ＡL/Ａtの調整方法］
伸び過ぎた第二相は、総冷間圧延加工度を高くする、延伸前の熱処理により調整する、延伸後に再圧延する、延伸後に熱処理を行う、等で分断することができ、平均アスペクト比ＡLを小さくすることができる。従って、これらの因子を適宜調整することにより、第二相の平均アスペクト比ＡL、ひいてはAL/Atを調整できる。 [At adjustment method]
Usually, when rolling, the thickness decreases in the thickness direction. In the present invention, the cast structure is refined by defining the additive element and its concentration, and when the rolling degree is increased, the ratio of the decrease in the thickness of the second phase is larger than that in the conventional multiphase alloy. Therefore, At in the direction perpendicular to the rolling becomes higher as the workability becomes higher than that in the conventional multiphase alloy even at the same workability. Therefore, the strength in the plate thickness direction is higher than that of conventional double phase alloys. On the other hand, since the second phase is likely to be divided as the rolling degree increases, the At of the second phase may be less than 10 by the heat treatment after rolling or after rolling. In this case, it is possible to adjust At by ensuring sufficient ductility by preventing the occurrence of shear bands by adjusting the tension during rolling, or by annealing the second phase by heat treatment. .
[AL / At adjustment method]
The excessively extended second phase can be divided by increasing the total cold rolling degree, adjusting by heat treatment before stretching, re-rolling after stretching, performing heat treatment after stretching, etc., and the average aspect ratio AL Can be reduced. Accordingly, by appropriately adjusting these factors, the average aspect ratio AL of the second phase, and hence AL / At can be adjusted.

次に、熱処理後に冷間圧延を行うが、Ａｔを大きくするには冷間圧延時の一パスあたりの加工度η＝0.16〜0.36（15〜30％），好ましくはη＝0.29（25%）以下程度と低くし，冷間圧延時にかける張力を80MPa〜300MPa、好ましくは200MPa以下に抑えるとよい。 Next, cold rolling is performed after heat treatment. To increase At, the degree of processing per pass during cold rolling η = 0.16 to 0.36 (15 to 30%), preferably η = 0.29 (25%) lower the degree or less, cold-applied during rolling tension 80MPa~300 M Pa, it may preferably kept below 200 MPa.

［第二相の厚み及び隣接する第二相の間隔］
図１において、隣接する第二相の間隔（圧延面方向の距離）をｄとする。本発明の合金の場合、圧延直角方向から見たとき、第二相の厚みｔ１及び第二相の間隔ｄが小さくなるほど、強度が高くなる。ｄは、圧延加工度を高くすることで小さくすることができる。特に、ｔ１及びｄが３μｍ以下である場合、より高い強度が得られるだけでなく，曲げ加工性が向上する。
上記したアスペクト比Ａｔの規定は第二相そのものの形状を規定するが，それだけでは曲げ加工性は向上しない。曲げ加工の際、曲げ応力が負荷される部位の第二相の厚さ及び間隔が大きいと破断しやすくなるからである。すなわち、曲げ加工性は、圧延平行断面又は直角断面において、組織写真上の第二相の積層方向に垂直に線を引いた際、この線を通過する母相と第二相（リボン状組織）の界面の数に依存する。そして、曲げ加工の際には第二相がすべて剪断されるだけの強度がこの材料の強度を示し、上記界面の数が多いほど強度が高くなると考えられる。従って，この界面の数を増やすためには，上記アスペクト比Ａｔを有し、かつ第二相の厚さと第二相間隔が小さい（３μｍ以下）ことが必要となる。例えば、本実施例中で最も強度が高いCu-Ag系合金のｔ及びｄは600nmである。 [Thickness of second phase and spacing between adjacent second phases]
In FIG. 1, let d be the interval between the adjacent second phases (distance in the rolling surface direction). In the case of the alloy of the present invention, the strength increases as the thickness t1 of the second phase and the interval d between the second phases decrease as viewed from the direction perpendicular to the rolling. d can be reduced by increasing the rolling degree. In particular, when t1 and d are 3 μm or less, not only higher strength is obtained, but also bending workability is improved.
The above-mentioned definition of the aspect ratio At defines the shape of the second phase itself, but it does not improve the bending workability. This is because, when the bending process is performed, if the thickness and interval of the second phase of the portion to which the bending stress is applied are large, breakage tends to occur. That is, in the bending workability, when a line is drawn perpendicularly to the lamination direction of the second phase on the structure photograph in a rolled parallel section or a right-angle section, the parent phase and the second phase (ribbon-like structure) that pass through this line are drawn. Depends on the number of interfaces. And, it is considered that the strength sufficient to shear all of the second phase at the time of bending shows the strength of this material, and the strength increases as the number of the interfaces increases. Therefore, in order to increase the number of the interfaces, it is necessary to have the above aspect ratio At, and to reduce the thickness of the second phase and the interval between the second phases (3 μm or less). For example, t and d of the Cu—Ag alloy having the highest strength in this example is 600 nm.

ｔ１及びｄを小さくすると、強度が向上する理由について説明する。複相合金は複合則を利用した強化機構であり，通常、複合則では材料の強度（σ：応力）は、第一相及び第二相の体積分率（それぞれV1,V2）に依存するが（σ＝V1σ1+V2σ2）、第二相の体積分率よりはむしろ分散した第二相間の距離の方が強度への寄与が大きい。つまり、第二相同士の間隔が加工によって狭まること、つまりＣｕ母相と第二相の異相界面の面積を増大させること、すなわち、Ｃｕ母相厚みが薄くなることが最も高強度化につながる。   The reason why the strength is improved when t1 and d are reduced will be described. A multiphase alloy is a strengthening mechanism that uses a composite law. In general, the strength (σ: stress) of a material depends on the volume fractions of the first and second phases (V1 and V2 respectively). (Σ = V1σ1 + V2σ2), rather than the volume fraction of the second phase, the distance between the dispersed second phases contributes more to the strength. That is, when the interval between the second phases is reduced by processing, that is, the area of the heterophase interface between the Cu matrix and the second phase is increased, that is, the thickness of the Cu matrix is thinned, the highest strength is obtained.

そして、第二相同士の間隔を狭めるためには、個々の第二相が微細となり、その厚みも小さくなっていることが必要である。すなわち、複相合金を強化するためには，第二相の初期晶出物を微細とさせ、さらにその後の加工により第二相を変形させて互いに近接させることが重要である。このため、（１）第二相が組織中に数多く分散しているほど（同じ体積分率の場合、第二相が微細に分散しているほど）、（２）第二相が引き伸ばされやすいほど，（３）加工度が大きくなるほど、高強度化される。これらの理由から，第二相の形状として上記アスペクト比を規定するとともに，ｔ１及びｄを制御すると、より高強度が得られる。
ここで、上記（１）については，添加元素を加えることにより、溶解鋳造時の晶出物がより微細化される。例えば、実際の溶解鋳造時のデンドライトアームスペース（個々のデンドライト状の初期晶出物同士の間隔）が１μm以下となることが観察されている。
（２）については，既に述べたように、第二相が延伸し易くなるような添加元素を選定することで実現が可能である。また，銅合金に対し、３００℃〜６００℃の温度で０．５〜２０時間の熱処理をすることで，Ｃｕ母相中に数百ｎｍオーダーの析出物を微細に析出させることができる。なお、この熱処理を冷間加工後に行うと，固溶した元素の拡散が促進され，析出し易くなるので望ましい。又、加工度が大きい時点で熱処理をすると、その後に冷間加工しても強度が向上し難いため，できるだけ低加工度における熱処理が望ましい。一方，加工前に熱処理をすると固溶元素が析出しにくくなるが，１５時間程度の長時間の熱処理を行えば微細に析出し，析出強化の効果が得られるので、加工前に熱処理をしてもよい。
（３）については，高い加工度で圧延することにより実現が可能である。 And in order to narrow the space | interval of 2nd phases, it is necessary for each 2nd phase to become fine and the thickness to also become small. That is, in order to reinforce the multiphase alloy, it is important to make the initial crystallized product of the second phase fine and further deform the second phase by subsequent processing so as to be close to each other. For this reason, (2) the more the second phase is dispersed in the structure (when the volume fraction is the same, the more the second phase is dispersed), (2) the second phase is more easily stretched. (3) The higher the degree of processing, the higher the strength. For these reasons, when the aspect ratio is defined as the shape of the second phase and t1 and d are controlled, higher strength can be obtained.
Here, with respect to the above (1), by adding an additive element, the crystallized product at the time of melting and casting is further refined. For example, it has been observed that the dendrite arm space (interval between individual dendrite-like initial crystals) during actual melting and casting is 1 μm or less.
As described above, (2) can be realized by selecting an additive element that makes the second phase easy to stretch. In addition, by subjecting the copper alloy to a heat treatment at a temperature of 300 ° C. to 600 ° C. for 0.5 to 20 hours, precipitates on the order of several hundred nm can be finely precipitated in the Cu matrix. In addition, it is desirable to perform this heat treatment after cold working because diffusion of solid solution elements is promoted and precipitation is facilitated. In addition, if the heat treatment is performed at a time when the degree of work is large, it is difficult to improve the strength even if it is subsequently cold worked. On the other hand, when heat treatment is performed before processing, solid solution elements are less likely to precipitate. However, if heat treatment is performed for a long time of about 15 hours, fine precipitation occurs and the effect of precipitation strengthening can be obtained. Also good.
(3) can be realized by rolling at a high workability.

ｔ１及びｄを制御する方法としては、例えば以下の方法がある。つまり、従来の複相合金においては溶解鋳造での組織制御は殆ど行われず，単純に第二相を晶出させ，熱処理と加工度で最終組織を制御することとしているが、本発明においては，１）第二相となる元素以外に，母相に分配される元素を添加することで晶出物を微細化されている。このように鋳造組織において晶出物間隔を制御することで、低加工度でもｔ１及びｄを微細化することができ、成分組成と濃度を調整することで最終的な組織のｔ１及びｄを制御できる。２）上記の如く晶出物は組成によって大きさが左右されるが，溶解鋳造時の冷却速度にも依存する。従って、凝固の際に発生する熱量を鋳型の熱容量が上回るように調整することが望ましく，好ましくは鋳型の熱容量が大きいほど良い。３）鋳型の冷却速度が速ければ速いほど，晶出物は微細になり、従来強加工によってしか得られなかったのと同様な微細組織を溶解鋳造で得ることが容易となる。従って、その後の加工と熱処理とを組み合わせることによって，ｔ１及びｄを制御可能である。   As a method for controlling t1 and d, for example, there are the following methods. In other words, in the conventional double phase alloy, the structure control in the melt casting is hardly performed, and the second phase is simply crystallized, and the final structure is controlled by the heat treatment and the working degree. 1) In addition to the element that becomes the second phase, the crystallized product is refined by adding an element distributed to the parent phase. In this way, by controlling the crystallized interval in the cast structure, t1 and d can be refined even at a low degree of processing, and the final structure t1 and d can be controlled by adjusting the component composition and concentration. it can. 2) As described above, the size of the crystallized product depends on the composition, but it also depends on the cooling rate during melt casting. Therefore, it is desirable to adjust the amount of heat generated during solidification so that the heat capacity of the mold exceeds, and preferably the heat capacity of the mold is larger. 3) The faster the cooling rate of the mold, the finer the crystallized material, and it becomes easier to obtain the same microstructure by melt casting that has been obtained only by conventional strong working. Therefore, t1 and d can be controlled by combining subsequent processing and heat treatment.

ただし，圧延加工時の張力や熱処理によって第二相のアスペクト比が変化し，また加工度によって第二相の厚さ，第二相間隔がともに変化する。従って、高強度を得るためには、好ましくは，冷間圧延の加工度が９０％以上になるよう、低加工度で熱処理を実施するのが良い。例えば、後述の実施例では，３０％の冷間加工後に４５０℃の熱処理をし，その後９９％の冷間圧延を実施している。   However, the aspect ratio of the second phase changes depending on the tension and heat treatment during rolling, and both the thickness of the second phase and the interval between the second phases change depending on the degree of processing. Therefore, in order to obtain high strength, it is preferable to perform the heat treatment at a low workability so that the workability of cold rolling is 90% or more. For example, in the examples described later, heat treatment at 450 ° C. is performed after 30% cold working, and then 99% cold rolling is performed.

［ＡL/Ａtの比］
さらに好ましくは、平均アスペクト比ＡｔとＡＬとが1<ＡＬ/Ａｔ<20の関係を満たすのがよい。ＡＬ/Aｔの比を上記範囲に規定することで、曲げ加工性としてMBR/ｔ≦１（安全曲げ半径、日本伸銅協会技術標準JBMA T307、「銅および銅合金薄板条の曲げ加工性評価方法、電気部品用銅および銅合金板条の曲げ加工性の評価方法」）となり、強度としてYS（降伏強さ）が700MPa以上となる材料が得られ、強度と曲げ加工性をともに満足することができる。
ここで、ＡＬ/Aｔの比が２０以上である場合、圧延直角方向への第二相の延伸が充分でなく、この方向での強度や曲げ加工性が劣化する。この場合に圧延直角方向の曲げ加工を行うと、銅母相と第二相の界面で亀裂が入りやすくなる。なお、通常の圧延では，ＡＬ/Ａｔが１以下となることは殆どないので，ＡＬ/Ａｔの下限は１程度であるが、これに限定されない。 [Ratio of AL / At]
More preferably, the average aspect ratio At and AL satisfy the relationship 1 <AL / At <20. By defining the AL / At ratio within the above range, MBR / t ≦ 1 (safe bending radius, JBMA T307, Japan Copper and Brass Association Technical Standard, “Method for evaluating the bending workability of copper and copper alloy strips” , An evaluation method for bending workability of copper and copper alloy strips for electrical parts "), and a material with a YS (yield strength) of 700 MPa or more as a strength can be obtained, satisfying both strength and bending workability. it can.
Here, when the ratio of AL / At is 20 or more, the second phase is not sufficiently stretched in the direction perpendicular to the rolling, and the strength and bending workability in this direction are deteriorated. In this case, if bending in the direction perpendicular to the rolling is performed, cracks are likely to occur at the interface between the copper matrix phase and the second phase. In normal rolling, AL / At hardly becomes 1 or less, so the lower limit of AL / At is about 1, but the present invention is not limited to this.

なお、複合則を考えたとき、圧延平行方向の強度を高めるにはALをAtより極めて大きくする必要があり、直角方向の強度を高めるにはAtをALより極めて大きくする必要がある。本発明者らの検討により、圧延平行方向及び圧延直角方向の強度、並びに強度の異方性の緩和という要求をいずれもバランスよく満す範囲がAL/At<20であることが判明した。つまり、Atは圧延直角方向の曲げ加工性を改善できる指標であるが、強度，曲げ加工性の異方性についてはAL/Atを指標とした方がよい。   When considering the compound rule, AL needs to be much larger than At to increase the strength in the rolling parallel direction, and At needs to be much larger than AL to increase the strength in the perpendicular direction. As a result of the study by the present inventors, it has been found that the range satisfying both the requirements of the strength in the rolling parallel direction and the direction perpendicular to the rolling and the relaxation of strength anisotropy in a balanced manner is AL / At <20. In other words, At is an index that can improve the bending workability in the direction perpendicular to the rolling direction, but it is better to use AL / At as an index for the anisotropy of strength and bending workability.

［ＡL/Ａtの調整方法］
本発明においては，成分組成を調整することにより、加工前の鋳造組織が微細化することにより，強加工圧延が必須ではない。したがってＡＬが大きくなり過ぎることは無く，ＡＬ／Ａｔ≦２０は比較的容易に達成される。しかしながら、大型のインゴットを途中で熱処理せずに冷間圧延した場合は，加工度が大きくなり，ＡＬが大きくなり過ぎる。その場合，圧延平行方向と圧延直角方向との異方性緩和のため、圧延中にＡＬ，及びＡｔの調整を実施するのが好ましく，例えば圧延での張力を大きくして第二相を分断する，もしくは熱処理によって分断する等の工程を加えるのが望ましい。
伸び過ぎた第二相は、冷間圧延加工度の総和（総加工度）を高くする、延伸前の熱処理により調整する、延伸後に再圧延する、延伸後に熱処理を行う、等で分断することができ、これにより平均アスペクト比ＡLを小さくすることができる。
次に、熱処理後に冷間圧延を行うことができるが、Ａｔを大きくするには冷間圧延時の一パスあたりの加工度η＝0.16〜0.36（15〜30％），好ましくはη＝0.29（25%）以下程度と低くし，冷間圧延時にかける張力を80MPa〜300MPa、好ましくは80MPa〜200MPaに抑えるとよい。 [AL / At adjustment method]
In the present invention, the high strength rolling is not essential because the cast structure before processing is refined by adjusting the component composition. Therefore, AL does not become too large, and AL / At ≦ 20 is achieved relatively easily. However, when a large ingot is cold-rolled without being heat-treated in the middle, the degree of work becomes large and AL becomes too large. In that case, it is preferable to adjust AL and At during rolling in order to mitigate the anisotropy between the rolling parallel direction and the rolling perpendicular direction. For example, the second phase is divided by increasing the tension in rolling. Alternatively, it is desirable to add a process such as dividing by heat treatment.
The second phase that has been stretched too much may be divided by increasing the total cold rolling work (total work), adjusting by heat treatment before stretching, rerolling after stretching, heat treating after stretching, etc. Thus, the average aspect ratio AL can be reduced.
Next, cold rolling can be performed after the heat treatment, but in order to increase At, the processing degree η = 0.16 to 0.36 (15 to 30%) per pass during cold rolling, preferably η = 0.29 ( 25%) or less, and the tension applied during cold rolling should be 80 to 300 MPa, preferably 80 to 200 MPa.

［製造］
電気銅又は無酸素銅を主原料とし、上記化学成分その他を添加した組成を溶解炉にて溶解し、インゴットを作製する。インゴットを例えば均質化焼鈍、熱間圧延、冷間圧延、焼鈍、冷間圧延、焼鈍を順次行うことで、圧延材が得られる。冷間圧延は、例えば加工度η＝3.5以上で行うことが好ましい。 [Manufacturing]
An ingot is prepared by melting a composition in which electrolytic copper or oxygen-free copper is used as a main raw material and adding the above chemical components and the like in a melting furnace. A rolled material can be obtained by sequentially performing, for example, homogenization annealing, hot rolling, cold rolling, annealing, cold rolling, and annealing on the ingot. Cold rolling is preferably performed, for example, at a working degree η = 3.5 or more.

なお、本発明は、上記実施形態に限定されない。
本発明の銅合金は、ばね用材料（条）、箔等の種々の形態とすることができる。例えば、本発明の銅合金をばね材用の条とした場合、コネクタ等の電子機器に適用可能である。コネクタとしては、公知のあらゆる形態、構造のものに適用できるが、通常はオス（ジャック、プラグ）とメス（ソケット、レセプタクル）からなっている。端子は、例えば串状の多数のピンが並設され、他のコネクタと嵌合した際に端子同士が電気的に接触するよう、適宜折り曲げられてバネのようになっていることがある。そして、通常、コネクタの端子が上記電子機器用銅合金で構成されている。
本発明の銅合金を箔とした場合、例えば、プリント配線板、特に可撓性銅張積層板に適用可能である。 In addition, this invention is not limited to the said embodiment.
The copper alloy of the present invention can be in various forms such as spring materials (strips) and foils. For example, when the copper alloy of the present invention is used for the spring material, it can be applied to electronic devices such as connectors. The connector can be applied to all known forms and structures, but is usually composed of a male (jack, plug) and a female (socket, receptacle). For example, the terminals may be formed as a spring by being bent as appropriate so that a number of skewer-like pins are juxtaposed and the terminals are in electrical contact with each other when fitted to other connectors. And the terminal of a connector is normally comprised with the said copper alloy for electronic devices.
When the copper alloy of the present invention is used as a foil, it can be applied to, for example, a printed wiring board, particularly a flexible copper-clad laminate.

次に、実施例を挙げて本発明をさらに詳細に説明するが、本発明はこれらに限定されるものではない。
<実験例Ａ>
試料の最終板厚を0.1ｍｍとし、ばね材用試料の特性を評価したものである。 EXAMPLES Next, although an Example is given and this invention is demonstrated further in detail, this invention is not limited to these.
<Experimental example A>
The final plate thickness of the sample was 0.1 mm, and the characteristics of the spring material sample were evaluated.

１．試料の作製
電気銅に表１、表２に示す組成の元素をそれぞれ添加して真空溶解してインゴットを鋳造し、これを800℃の温度で3時間の条件で均質化焼鈍後、熱間圧延を施した。さらに面削して冷間圧延を行い、伸ばされた第二相を分断するために450℃の焼鈍を行い、仕上げ冷間圧延を行い、板厚0.1ｍｍのばね材用試料を作製した。冷間圧延の間に所定の時効処理を施した。冷間圧延の総圧延加工度を99.7％とし、1パスあたりの加工度30〜36％，張力350MPa以上（ただし、冷間圧延の初期パスでは150MPa、板厚が薄くなった後期パスでは375MPa程度）とした。
又、第二相の形態は、試料の断面ＳＥＭのＢＳＥ像から求めた。 1. Preparation of sample Ingot was cast by adding elements of the composition shown in Tables 1 and 2 to electrolytic copper, and vacuum-melting to cast an ingot. This was homogenized and annealed at 800 ° C for 3 hours, and then hot rolled. Was given. Further, chamfering was performed and cold rolling was performed. In order to divide the stretched second phase, annealing was performed at 450 ° C., finish cold rolling was performed, and a sample for a spring material having a plate thickness of 0.1 mm was produced. A predetermined aging treatment was applied during cold rolling. The total rolling degree of cold rolling is 99.7%, the degree of working per pass is 30 to 36%, and the tension is 350MPa or more (however, the initial pass of cold rolling is 150MPa, and the latter pass when the plate thickness is reduced is about 375MPa) ).
The form of the second phase was determined from the BSE image of the cross section SEM of the sample.

<試料の評価>
（１）強度の評価
JIS-Z2241に従い、試料の引張強度を測定し、０．２％耐力（ＹＳ：yielding strength）を求めた。試料はＪＩＳに従って作製した。
（２）導電性の評価
四端子法にて、試料の導電率を求めた。単位の％ＩＡＣＳ（international annealed copper standard）は、焼鈍標準軟銅に対する電気伝導度の比である。 <Sample evaluation>
(1) Strength evaluation
According to JIS-Z2241, the tensile strength of the sample was measured to obtain 0.2% yield strength (YS). The sample was produced according to JIS.
(2) Evaluation of conductivity The conductivity of the sample was determined by the four probe method. The unit% IACS (international annealed copper standard) is the ratio of electrical conductivity to annealed standard soft copper.

（３）曲げ加工性の評価
日本伸銅協会技術標準（JBMA T307）に従ってＷ曲げ試験を行った。圧延直角方向に延びる１０ｍｍ幅の試料（ｔ：試料厚さ）について最小曲げ半径（ＭＢＲ）を求めた。そして、以下の基準で各実験例及び比較例の試料を評価した。
○：ＭＢＲ／ｔの値が基準例の値より小さいもの
△：ＭＢＲ／ｔの値が基準例の値より大きいもの
×：ＭＢＲ／ｔの値が基準例の値よりかなり大きいもの
基準例のＭＢＲ／ｔは１程度である。 (3) Evaluation of bending workability A W bending test was performed according to the Japan Copper and Brass Association Technical Standard (JBMA T307). The minimum bending radius (MBR) was determined for a 10 mm wide sample (t: sample thickness) extending in the direction perpendicular to the rolling. The samples of each experimental example and comparative example were evaluated according to the following criteria.
○: MBR / t value is smaller than the reference example value Δ: MBR / t value is larger than the reference example value ×: MBR / t value is considerably larger than the reference example value MBR of the reference example / T is about 1.

得られた結果を表１、表２に示す。   The obtained results are shown in Tables 1 and 2.

各表から明らかなように、実施例１〜２０（参考例７〜９を除く）の場合、強度、導電性、曲げ加工性がいずれも優れ、性能上のバランスのよい銅合金（ばね材用）を得ることができた。 As is clear from each table, in Examples 1 to 20 (except Reference Examples 7 to 9) , the copper alloy (for spring material) has excellent strength, conductivity, and bending workability and has a good balance in performance. )

一方、Fe含有量が７％未満である比較例１の場合、第二相が晶出せず、強度が低下した。又、Fe含有量が２０％を超えた比較例２の場合、Ａｔ（第二相のアスペクト比）が１０未満となり、導電性、曲げ加工性が低下した。
添加元素の含有量が0.01％未満である比較例３、５、７、９の場合、0.2％耐力が750MPa未満となった。
添加元素の含有量が1％を超えた比較例４、６、８、１０〜１５の場合、Ａｔ（第二相のアスペクト比）が１０未満となり、曲げ加工性が低下した。
冷間圧延時の総加工度を７０％としたためにＡｔ（第二相のアスペクト比）が１０未満となり、さらに第二相の厚さ及び間隔が３μｍを超えた比較例１６〜１９の場合、0.2％耐力が750MPa未満となった。
冷間圧延時の熱処理温度を２５０℃としたためにＡｔ（第二相のアスペクト比）が１０未満となった比較例２０〜２３の場合、0.2％耐力が750MPa未満となったと共に、曲げ加工性が低下した。 On the other hand, in the case of the comparative example 1 whose Fe content is less than 7%, the second phase was not crystallized, and the strength was lowered. Further, in Comparative Example 2 in which the Fe content exceeded 20%, At (aspect ratio of the second phase) was less than 10, and conductivity and bending workability were deteriorated.
In Comparative Examples 3, 5, 7, and 9 in which the content of the additive element was less than 0.01%, the 0.2% proof stress was less than 750 MPa.
In Comparative Examples 4, 6, 8, and 10-15 in which the content of the additive element exceeded 1%, At (aspect ratio of the second phase) was less than 10, and bending workability was deteriorated.
In the case of Comparative Examples 16 to 19 in which At (aspect ratio of the second phase) was less than 10 because the total workability during cold rolling was 70%, and the thickness and interval of the second phase exceeded 3 μm, The 0.2% proof stress was less than 750 MPa.
In Comparative Examples 20 to 23 in which At (second phase aspect ratio) was less than 10 because the heat treatment temperature during cold rolling was 250 ° C., 0.2% proof stress was less than 750 MPa, and bending workability Decreased.

<実験例Ｂ>
実験例Ｂは、試料は上記実施例１〜２０、比較例１〜２３と同一であるが、最終板厚を0.05ｍｍの箔とし、箔用試料の特性を評価したものである。実験は、上記実験例Ａで得られた試料を二等分し，これをさらに０．０５ｍｍまで圧延した。したがって総加工度は９９．８８％となった。
なお、実験例Ｂでは、箔の特性評価として、以下の屈曲性評価を行った。
（４）屈曲性の評価
MIT屈曲性試験により、屈曲性の評価を行った。試験条件は、曲げ半径2.0mm，曲げ荷重500ｇ，折り曲げ角度が左右へ135°とし、試料は、板厚50μmのものを用いた。破断に至るまでの曲げ回数を数え、以下の評価をした。
○：曲げ回数が基準例より多いもの（通常、１００回を超えるもの）
△：曲げ回数が基準例と同等のもの
×：曲げ回数が基準例より少ないもの <Experiment B>
In Experimental Example B, the samples are the same as those in Examples 1 to 20 and Comparative Examples 1 to 23, but the final plate thickness is 0.05 mm foil, and the characteristics of the foil samples are evaluated. In the experiment, the sample obtained in Experimental Example A was divided into two equal parts, which were further rolled to 0.05 mm. Therefore, the total processing degree was 99.88%.
In Experimental Example B, the following flexibility evaluation was performed as the foil characteristic evaluation.
(4) Evaluation of flexibility
Flexibility was evaluated by the MIT flexibility test. The test conditions were a bending radius of 2.0 mm, a bending load of 500 g, a bending angle of 135 ° to the left and right, and a sample having a plate thickness of 50 μm. The number of times of bending until rupture was counted and evaluated as follows.
○: The number of times of bending is greater than the reference example (usually more than 100 times)
△: The number of bendings is the same as the reference example ×: The number of bendings is less than the reference example

得られた結果を表３、表４に示す。   The obtained results are shown in Tables 3 and 4.

各表から明らかなように、実施例１〜２０（参考例７〜９を除く）の場合、強度、導電性、曲げ加工性がいずれも優れ、性能上のバランスのよい銅合金（箔用）を得ることができた。 As is clear from each table, in Examples 1 to 20 (except Reference Examples 7 to 9) , the copper alloy (for foil) has excellent strength, conductivity, and bending workability and has a good balance in performance. Could get.

一方、Fe含有量が７％未満である比較例１の場合、第二相が晶出せず、強度が低下した。又、Fe含有量が２０％を超えた比較例２の場合、Ａｔ（第二相のアスペクト比）が１０未満となり、導電性、屈曲性が低下した。
添加元素の含有量が0.01％未満である比較例３、５、７、９の場合、0.2％耐力が750MPa未満となった。
添加元素の含有量が1％を超えた比較例４、６、８、１０〜１５の場合、Ａｔ（第二相のアスペクト比）が１０未満となり、屈曲性が低下した。
冷間圧延時の熱処理温度を２５０℃としたためにＡｔ（第二相のアスペクト比）が１０未満となった比較例２０〜２３の場合、0.2％耐力が750MPa未満となったと共に、屈曲性が低下した。 On the other hand, in the case of the comparative example 1 whose Fe content is less than 7%, the second phase was not crystallized, and the strength was lowered. Further, in Comparative Example 2 in which the Fe content exceeded 20%, At (aspect ratio of the second phase) was less than 10, and the conductivity and flexibility were lowered.
In Comparative Examples 3, 5, 7, and 9 in which the content of the additive element was less than 0.01%, the 0.2% proof stress was less than 750 MPa.
In Comparative Examples 4, 6, 8, and 10-15 in which the content of the additive element exceeded 1%, At (aspect ratio of the second phase) was less than 10, and flexibility was lowered.
In Comparative Examples 20 to 23 in which At (aspect ratio of the second phase) was less than 10 because the heat treatment temperature during cold rolling was 250 ° C., the 0.2% proof stress was less than 750 MPa and the flexibility was Declined.

なお、Ｓｎを0.1％添加した本発明の合金（Ｃｕ−１５Ｆｅ−０．１Ｓｎ）の圧延前のインゴットのＳＥＭのＢＳＥ像を図２に示す。図２の黒い領域が第二相、白い領域がＣｕ母相を示す。図３は、Ｓｎを添加しなかった合金（Ｃｕ−１５Ｆｅ）の圧延前のインゴットのＳＥＭのＢＳＥ像を示す。図２，３から明らかなように、Ｓｎを0.1％添加することにより、第二相が微細に晶出し、かつ第二相同士の間隔も狭くて組織中に均一に晶出したことがわかり、これを冷間圧延することによって第二相が変形してさらに微細になることが予想される。   In addition, the SEM BSE image of the ingot before rolling of the alloy (Cu-15Fe-0.1Sn) of the present invention to which 0.1% of Sn is added is shown in FIG. The black region in FIG. 2 represents the second phase, and the white region represents the Cu matrix. FIG. 3 shows an SEM BSE image of an ingot before rolling of an alloy to which Sn was not added (Cu-15Fe). As is apparent from FIGS. 2 and 3, by adding 0.1% of Sn, it can be seen that the second phase is finely crystallized, and the interval between the second phases is narrow and crystallized uniformly in the structure. It is expected that the second phase is deformed and becomes finer by cold rolling.

本発明の合金の圧延材組織を模式的に示した図である。It is the figure which showed typically the rolling material structure | tissue of the alloy of this invention. 圧延前のＣｕ−１５Ｆｅ−０．１Ｓｎ試料（インゴット）の組織のＳＥＭのＢＳＥ像を示す図である。It is a figure which shows the BSE image of SEM of the structure | tissue of the Cu-15Fe-0.1Sn sample (ingot) before rolling. 圧延前のＣｕ−１５Ｆｅ試料（インゴット）の組織のＳＥＭのＢＳＥ像を示す別の図である。It is another figure which shows the BSE image of SEM of the structure | tissue of the Cu-15Fe sample (ingot) before rolling.

符号の説明Explanation of symbols

２ Ｃｕ母材
４ 第二相 2 Cu base material 4 Second phase

Claims (2)

質量％でFeを7％以上20％以下含有すると共にMg,Ag,Sn及びZrの群から選ばれる１種又は２種以上を合計で0.01％以上1％以下含有し残部Cu及び不可避的不純物からなり、Cu母相と第二相とからなる0.2％耐力が750MPa以上の圧延材であって、圧延直角断面から見たとき、前記第二相の厚み及び圧延面方向に隣接する第二相の間隔が3μｍ以下であり、かつ前記第二相の平均アスペクト比Ａｔが10≦Ａｔ≦80である、高強度高導電性二相銅合金。 Containing not less than 7% and not more than 20% Fe by mass, and containing one or more selected from the group of Mg, Ag, Sn, and Zr in a total of not less than 0.01% and not more than 1%, with the balance being Cu and inevitable impurities A 0.2% proof stress of 750 MPa or more consisting of a Cu parent phase and a second phase, and when viewed from a cross section perpendicular to the rolling, the thickness of the second phase and the second phase adjacent to the rolling surface direction A high-strength, high-conductivity, two-phase copper alloy having an interval of 3 μm or less and an average aspect ratio At of the second phase of 10 ≦ At ≦ 80. 前記第二相を前記圧延直角断面から見たときの平均アスペクト比Ａｔと、前記第二相を圧延平行断面から見たときの平均アスペクト比ＡＬとが、ＡＬ/Ａｔ<20の関係を満たす、請求項１に記載の高強度高導電性二相銅合金。   The average aspect ratio At when the second phase is viewed from the cross-section perpendicular to the rolling and the average aspect ratio AL when the second phase is viewed from the rolling parallel section satisfy the relationship AL / At <20. The high-strength and highly conductive two-phase copper alloy according to claim 1.