JP5028657B2 - High-strength copper alloy sheet with little anisotropy and method for producing the same - Google Patents

Description

本発明は、コネクター、リードフレーム、リレー、スイッチなどの電気・電子部品に適した銅合金材料であって、特に高強度および優れた曲げ加工性を維持しながら、それらの特性についての「異方性」を改善した銅合金板材に関する。   The present invention is a copper alloy material suitable for electrical and electronic parts such as connectors, lead frames, relays, switches, etc., and particularly with respect to their properties while maintaining high strength and excellent bending workability. The present invention relates to a copper alloy sheet having improved properties.

電気・電子部品を構成するコネクター、リードフレーム、リレー、スイッチなどの通電部品に使用される材料には、通電によるジュール熱の発生を抑制するために良好な「導電性」が要求されるとともに、電気・電子機器の組立時や作動時に付与される応力に耐え得る高い「強度」が要求される。また、電気・電子部品は一般に曲げ加工により成形されることから優れた「曲げ加工性」も要求される。しかし、「強度」と「導電性」、あるいは特に「強度」と「曲げ加工性」の間にはトレードオフの関係がある。従来、このような通電部品には、用途に応じて「導電性」、「強度」あるいは「曲げ加工性」の良好な材料が適宜選択されて使用されている。   The materials used for current-carrying parts such as connectors, lead frames, relays, and switches that make up electrical and electronic parts are required to have good "conductivity" to suppress the generation of Joule heat due to current flow. High “strength” is required to withstand the stress applied during assembly and operation of electrical and electronic equipment. In addition, since electric / electronic parts are generally formed by bending, excellent “bending workability” is also required. However, there is a trade-off relationship between “strength” and “conductivity” or particularly “strength” and “bending workability”. Conventionally, materials having good “conductivity”, “strength” or “bending workability” are appropriately selected and used for such energized parts depending on the application.

近年、電気・電子部品は高集積化、小型化および軽量化が進む傾向にあり、それに伴って素材である銅および銅合金には薄肉化の要求が高まっている。そのため、素材に要求される強度レベルは一層厳しいものとなっている。また、電気・電子部品の小型化（省スペース化、部品形状の複雑化）に対応するには部品の設計自由度を拡大することが重要であり、そのためには材料の「曲げ加工性」の向上が不可欠である。   In recent years, electrical and electronic parts have been increasingly integrated, miniaturized and lightened, and accordingly, copper and copper alloys as materials have been required to be thin. For this reason, the strength level required for the material is more severe. Also, in order to cope with the miniaturization of electrical and electronic parts (space saving, complexity of part shape), it is important to expand the degree of design freedom of parts. Improvement is essential.

銅合金の一般的な強化機構として、固溶強化、析出強化、加工硬化が挙げられる。このうち固溶強化は導電性の低下を招きやすい。銅合金の導電性を高レベルに維持しながら高強度化を達成するには析出強化を利用することが有利である。一方、加工硬化は伝統的な強化手法であり、圧延によって顕著な強化効果が得られ導電性の低下も小さいことから、生産性が高くコスト面でも有利な方法であると言える。したがって、析出強化型銅合金でも顕著な高強度化を狙う場合は、仕上げ冷間圧延（調質処理）による加工硬化を併用することが有効かつ一般的な方法である。   Common strengthening mechanisms for copper alloys include solid solution strengthening, precipitation strengthening, and work hardening. Among these, solid solution strengthening tends to cause a decrease in conductivity. In order to achieve high strength while maintaining the conductivity of the copper alloy at a high level, it is advantageous to use precipitation strengthening. On the other hand, work hardening is a traditional strengthening method, and a remarkable strengthening effect is obtained by rolling, and the decrease in conductivity is small. Therefore, it can be said that it is a highly productive and cost-effective method. Therefore, when aiming at a remarkable increase in strength even for precipitation strengthened copper alloys, it is an effective and general method to use work hardening by finish cold rolling (tempering treatment) in combination.

しかしながら、冷間圧延を行うと、圧延方向に対して平行方向（ＬＤ）と直角方向（ＴＤ）とで機械的性質に差（異方性）が生じることが通常、避けられない。例えば、引張強さは一般にＴＤの方がＬＤより高くなり、曲げ加工性はＴＤにおいて（すなわち曲げ軸がＬＤとなる場合に）低下しやすい。部品の設計自由度拡大を図るにはこの異方性の低減が重要である。板材の異方性が大きくなると、強度レベルと導電性レベルが高くても電気・電子部品に使用できなくなる場合がある。   However, when cold rolling is performed, it is usually unavoidable that a difference (anisotropy) occurs in mechanical properties between the direction parallel to the rolling direction (LD) and the direction perpendicular to the direction (TD). For example, the tensile strength is generally higher in TD than in LD, and the bending workability tends to decrease in TD (that is, when the bending axis is LD). It is important to reduce this anisotropy in order to increase the degree of design freedom of parts. If the anisotropy of the plate material is increased, it may be impossible to use it for electric / electronic parts even if the strength level and the conductivity level are high.

強度と導電性のバランスに優れた銅合金としてＣｕ−Ｎｉ−Ｓｉ系合金（いわゆるコルソン合金）が近年注目されている。この系の銅合金は、溶体化処理、冷間圧延、時効処理、仕上げ冷間圧延、低温焼鈍を基本とする工程により、強度を顕著に向上させることができる。しかし、これに伴って異方性が生じ、しばしば問題となる。   In recent years, a Cu—Ni—Si based alloy (so-called Corson alloy) has attracted attention as a copper alloy having an excellent balance between strength and conductivity. This type of copper alloy can remarkably improve the strength by processes based on solution treatment, cold rolling, aging treatment, finish cold rolling, and low temperature annealing. However, this causes anisotropy, which is often a problem.

そこで、Ｃｕ−Ｎｉ−Ｓｉ系合金において、組織状態を制御する手法が種々提案されている（特許文献１〜４）。なかでも特許文献２、４には、Ｃｕ−Ｎｉ−Ｓｉ系合金の圧延集合組織をＸ線回折強度比によって規定することが記載されている。   Thus, various techniques for controlling the structure state of Cu—Ni—Si based alloys have been proposed (Patent Documents 1 to 4). In particular, Patent Documents 2 and 4 describe that the rolling texture of a Cu—Ni—Si alloy is defined by the X-ray diffraction intensity ratio.

特開２００２−３８２２８号公報JP 2002-38228 A 特開２００６−９１０８号公報JP 2006-9108 A 特開平５−２７９８２５号公報JP-A-5-279825 特開２０００−８０４２８号公報JP 2000-80428 A

圧延材の異方性は、主に圧延集合組織（冷間圧延することにより成長する集合組織）に起因するものである。ｆｃｃ構造の銅合金の場合、圧延集合組織は、添加元素の種類および添加量並びに圧延率によって多少相違するが、基本的に｛１１０｝＜１１２＞を主方位成分とするものである。すなわち冷間圧延すると、圧延板は｛１１０｝結晶面が圧延面に平行になり、＜１１２＞結晶方向が圧延方向に平行になるような結晶配向をとろうとする。   The anisotropy of the rolled material is mainly caused by a rolling texture (a texture that grows by cold rolling). In the case of a copper alloy having an fcc structure, the rolling texture is somewhat different depending on the type and amount of additive elements and the rolling rate, but basically has {110} <112> as the main orientation component. That is, when cold rolling is performed, the rolled plate tends to take a crystal orientation such that the {110} crystal plane is parallel to the rolled surface and the <112> crystal direction is parallel to the rolling direction.

特許文献２では、この圧延集合組織を抑制することを異方性低減の手段の１つとしている。しかし、昨今の厳しい部品設計に対応するには、曲げ加工性レベルの更なる向上が望まれる。特許文献４では、｛２００｝面、｛３１１｝面および｛２２０｝面のＸ線回折強度が特定範囲になる結晶配向を異方性低減の手段としている。しかし、この場合も昨今のニーズを考慮すると、より安定的に優れた曲げ加工性が得られ、かつ、更に高い強度レベルが得られることが望まれる。また特許文献２、４いずれの場合も、引張強さの異方性を低減させることに関し、十分な配慮がなされていない。   In Patent Document 2, suppressing the rolling texture is one of the means for reducing the anisotropy. However, further improvement in the level of bending workability is desired in order to cope with the recent severe part design. In Patent Document 4, the crystal orientation in which the X-ray diffraction intensities of the {200} plane, {311} plane, and {220} plane are in a specific range is used as a means for reducing anisotropy. However, in this case as well, considering recent needs, it is desired that a superior bending workability can be obtained more stably and a higher strength level can be obtained. In both cases of Patent Documents 2 and 4, sufficient consideration is not given to reducing the anisotropy of tensile strength.

このように、諸特性のバランスに比較的優れるＣｕ−Ｎｉ−Ｓｉ系銅合金において、更なる高強度化を図りながら異方性を顕著に改善する技術は未だ確立されていない。
本発明は、この合金系において、特に引張強さと曲げ加工性を高レベルに維持しながら、それらの特性についての異方性を顕著に改善した銅合金板材を提供することを目的とする。 As described above, a technique for remarkably improving anisotropy while further increasing the strength of a Cu—Ni—Si based copper alloy having a relatively excellent balance of various properties has not yet been established.
An object of the present invention is to provide a copper alloy sheet material in which the anisotropy of these characteristics is remarkably improved while maintaining the tensile strength and bending workability at a high level in this alloy system.

前述のように、銅合金板材を圧延した際に発達する圧延集合組織は基本的に｛１１０｝＜１１２＞を主方位成分とするものである。このような集合組織が発達するに伴い、ＴＤの引張強さがＬＤよりも大きくなるとともにＴＤの曲げ加工性が低下する。一方、｛１００｝＜００１＞を主方位成分とする純銅型再結晶集合組織を持つ銅合金板材では、上記と反対の異方性を呈する。つまり、このとき引張強さはＬＤの方が高くなり、曲げ加工性はＬＤの方が低下する。発明者らは詳細な検討の結果、これら２種類の集合組織の中間的な結晶配向を持つ組織状態にコントロールしたとき、互いの集合組織で優勢な異方性が相殺され、引張強さ、曲げ加工性ともＬＤとＴＤの差を顕著に低減させることが可能になることを見出した。   As described above, the rolling texture developed when a copper alloy sheet is rolled basically has {110} <112> as the main orientation component. As such a texture develops, the tensile strength of TD becomes larger than that of LD, and the bending workability of TD decreases. On the other hand, a copper alloy sheet having a pure copper-type recrystallized texture with {100} <001> as the main orientation component exhibits the anisotropy opposite to the above. That is, at this time, the tensile strength is higher in the LD, and the bending workability is lower in the LD. As a result of detailed studies, the inventors have controlled the texture state having an intermediate crystal orientation of these two types of textures to cancel the dominant anisotropy in each other's textures, and to improve the tensile strength and bending. It has been found that the difference between LD and TD can be remarkably reduced in terms of workability.

｛１００｝＜００１＞を主方位成分とする再結晶集合組織は、Ｃｕ−Ｎｉ−Ｓｉ系銅合金の場合、特定範囲に組成調整した上で、６０％以上、望ましくは８５以上という大きな圧延率で冷間圧延を行った材料に対して溶体化処理を施すことにより実現できることがわかった。この「再結晶集合組織」をもつ材料に仕上げ冷間圧延を施すと、次第に｛１１０｝＜１１２＞を主方位成分とする「圧延集合組織」が発達していき、上記２種類の集合組織の中間的な結晶配向となったときにＬＤとＴＤの特性差が非常に小さい状態が実現できる。また、この仕上げ冷間圧延により強度レベルも向上する。このため、引張強さ７００ＭＰａ以上の高強度化と異方性低減が一挙に達成される。本発明はこのような知見に基づいて完成したものである。   In the case of a Cu—Ni—Si based copper alloy, the recrystallization texture whose main orientation component is {100} <001> is a large rolling ratio of 60% or more, preferably 85 or more after adjusting the composition within a specific range. It was found that this can be realized by subjecting the material subjected to cold rolling to solution treatment. When finish cold rolling is performed on a material having this “recrystallized texture”, a “rolled texture” having {110} <112> as a main orientation component gradually develops, and the two types of textures described above are developed. A state in which the difference in characteristics between LD and TD is very small when an intermediate crystal orientation is obtained can be realized. The strength level is also improved by this finish cold rolling. For this reason, an increase in tensile strength of 700 MPa or more and a reduction in anisotropy are achieved at once. The present invention has been completed based on such findings.

すなわち本発明では、質量％で、Ｎｉ：０.７〜２.５％、Ｓｉ：０.２〜０.７％を含有し、さらに必要に応じてＳｎ：１.０％以下、Ｍｇ：０.３％以下の範囲で含有し、残部実質的にＣｕの組成を有し、下記（１）式および（２）式を満たす結晶配向を有する銅合金板材が提供される。上記組成において、さらにＺｎ、Ｃｏ、Ｃｒ、Ｂ、Ｆｅ、Ｚｒ、Ｔｉ、Ｍｎの１種以上を合計３％以下の範囲で含有することができる。
３.０≦Ｉ｛２２０｝／Ｉ₀｛２２０｝≦６.０ ……（１）
１.５≦Ｉ｛２００｝／Ｉ₀｛２００｝≦２.５ ……（２）
ここで、Ｉ｛２２０｝およびＩ｛２００｝はそれぞれ当該板材の板面における｛２２０｝結晶面および｛２００｝結晶面のＸ線回折強度であり、Ｉ₀｛２２０｝およびＩ₀｛２００｝はそれぞれ純銅標準粉末の｛２２０｝結晶面および｛２００｝結晶面のＸ線回折強度である。「板面」は板の厚さ方向に垂直な表面（圧延面）である。 That is, in the present invention, by mass%, Ni: 0.7 to 2.5%, Si: 0.2 to 0.7% are contained, and Sn: 1.0% or less, Mg: 0 if necessary. There is provided a copper alloy sheet material that is contained in the range of .3% or less, the balance is substantially Cu, and has a crystal orientation that satisfies the following formulas (1) and (2). In the above composition, one or more of Zn, Co, Cr, B, Fe, Zr, Ti, and Mn can be further contained within a total range of 3% or less.
3.0 ≦ I {220} / I ₀ {220} ≦ 6.0 (1)
1.5 ≦ I {200} / I ₀ {200} ≦ 2.5 (2)
Here, I {220} and I {200} are the X-ray diffraction intensities of the {220} crystal plane and {200} crystal plane on the plate surface of the plate, respectively, and I ₀ {220} and I ₀ {200}. Are the X-ray diffraction intensities of the {220} crystal plane and {200} crystal plane of pure copper standard powder, respectively. The “plate surface” is a surface (rolled surface) perpendicular to the thickness direction of the plate.

「残部実質的にＣｕ」とは、本発明の効果を阻害しない範囲で上記以外の元素の混入が許容されることを意味し、「残部がＣｕおよび不可避的不純物」である場合が含まれる。   “Remainder substantially Cu” means that mixing of elements other than the above is allowed within a range that does not impair the effects of the present invention, and includes the case where “remainder is Cu and inevitable impurities”.

この銅合金板材は、板面において圧延方向に対し平行方向をＬＤ、直角方向をＴＤと呼ぶとき、引張強さについてＬＤとＴＤの差の絶対値が３０ＭＰａ以下、９０°Ｗ曲げ試験での最小曲げ半径Ｒ（ｍｍ）と板厚ｔ（ｍｍ）の比Ｒ／ｔについてＬＤとＴＤの差の絶対値が０.５以下である特性を有する。   In this copper alloy sheet, when the parallel direction to the rolling direction is called LD and the perpendicular direction is called TD on the plate surface, the absolute value of the difference between LD and TD is 30 MPa or less in terms of tensile strength, and the minimum in a 90 ° W bending test. The ratio R / t of the bending radius R (mm) and the plate thickness t (mm) has a characteristic that the absolute value of the difference between LD and TD is 0.5 or less.

９０°Ｗ曲げ試験はＪＩＳ Ｈ３１１０に準拠した試験法が採用される。ＬＤのＲ／ｔ値は試験片長手方向がＬＤ、曲げ軸がＴＤとなる場合の値を意味し、ＴＤのＲ／ｔ値は試験片長手方向がＴＤ、曲げ軸がＬＤとなる場合の値を意味する。   For the 90 ° W bending test, a test method based on JIS H3110 is adopted. The R / t value of LD means the value when the test piece longitudinal direction is LD and the bending axis is TD, and the TD R / t value is the value when the test piece longitudinal direction is TD and the bending axis is LD. Means.

上記銅合金板材の製造法として、上記のように組成調整された銅合金の熱間圧延材または焼鈍材に対し、６０％以上望ましくは８５以上の冷間圧延、溶体化処理、４００〜５００℃の時効処理、１０〜６５％望ましくは２５〜６０％の仕上げ冷間圧延を前記の順で施す工程を有する製造法が提供される。その仕上げ冷間圧延後に、２５０〜５００℃の加熱処理を施すことができる。   As a method for producing the copper alloy sheet, 60% or more, preferably 85 or more cold rolling, solution treatment, 400 to 500 ° C. with respect to the hot-rolled or annealed material of the copper alloy whose composition is adjusted as described above. A aging treatment of 10 to 65%, preferably 25 to 60% of finish cold rolling is provided in the order described above. After the finish cold rolling, heat treatment at 250 to 500 ° C. can be performed.

本発明によれば、コネクター、リードフレーム、リレー、スイッチなどの電気・電子部品に必要な基本特性を具備するＣｕ−Ｎｉ−Ｓｉ系銅合金の板材において、引張強さ７００ＭＰａ以上あるいはさらに７２０ＭＰａ以上の高強度と、９０°Ｗ曲げ試験における最小曲げ半径Ｒと板厚ｔの比Ｒ／ｔが１以下の優れた曲げ加工性を呈し、かつこれらの特性についての異方性が顕著に低減された。このような高強度レベルにおいて引張強さと曲げ加工性の異方性の安定して顕著に低減することは、従来のＣｕ−Ｎｉ−Ｓｉ系銅合金製造技術では困難であった。本発明は、今後ますます進展が予想される電気・電子部品の小型化、薄肉化のニーズに対応し得るものである。   According to the present invention, a Cu—Ni—Si based copper alloy plate material having basic characteristics required for electrical / electronic components such as connectors, lead frames, relays, switches, etc., has a tensile strength of 700 MPa or more, or even 720 MPa or more. High strength, excellent bending workability with a ratio R / t of the minimum bending radius R to the sheet thickness t in the 90 ° W bending test of 1 or less, and anisotropy with respect to these properties were significantly reduced. . It has been difficult for the conventional Cu—Ni—Si copper alloy manufacturing technology to stably and significantly reduce the anisotropy of tensile strength and bending workability at such a high strength level. The present invention can meet the needs for downsizing and thinning of electric and electronic parts, which are expected to make further progress in the future.

〔合金組成〕
本発明ではＣｕ−Ｎｉ−Ｓｉ系銅合金を採用する。Ｃｕ−Ｎｉ−Ｓｉの３元系基本成分にＳｎ、Ｚｎその他の合金元素を添加した銅合金も、本明細書では包括的にＣｕ−Ｎｉ−Ｓｉ系銅合金と称している。 [Alloy composition]
In the present invention, a Cu—Ni—Si based copper alloy is employed. A copper alloy obtained by adding Sn, Zn or other alloy elements to a Cu—Ni—Si ternary basic component is also referred to as a Cu—Ni—Si copper alloy in this specification.

ＮｉおよびＳｉは、析出物を形成し、強度上昇および導電性・熱伝導度向上に寄与する。Ｎｉ含有量が０.７質量％未満またはＳｉ含有量が０.２質量％未満では、上記効果を有効に引き出すことが難しい。一方、Ｎｉ含有量が２.５質量％を超える場合やＳｉ含有量が０.８質量％を超える場合は粗大な析出物が生成しやすいので、板材の曲げ加工性がＬＤとＴＤともに低下しやすい。また、溶体化処理において後述する｛１００｝＜００１＞を主方位成分とする再結晶集合組織を発達させることが難しくなり、最終的に異方性が十分低された板材を得ることが困難になる。このためＮｉ含有量は０.７〜２.５質量％、Ｓｉ含有量は０.２〜０.８質量％とする。より好ましいＮｉ含有量範囲は１.２〜２.２質量％、より好ましいＳｉ含有量範囲は０.３〜０.６質量％である。   Ni and Si form precipitates and contribute to an increase in strength and an improvement in conductivity and thermal conductivity. When the Ni content is less than 0.7% by mass or the Si content is less than 0.2% by mass, it is difficult to effectively bring out the above effects. On the other hand, when the Ni content exceeds 2.5% by mass or the Si content exceeds 0.8% by mass, coarse precipitates are likely to be formed, so that the bending workability of the plate material decreases for both LD and TD. Cheap. Further, it becomes difficult to develop a recrystallized texture having {100} <001> as a main orientation component, which will be described later, in the solution treatment, and finally it is difficult to obtain a plate material with sufficiently low anisotropy. Become. Therefore, the Ni content is set to 0.7 to 2.5% by mass, and the Si content is set to 0.2 to 0.8% by mass. A more preferable Ni content range is 1.2 to 2.2% by mass, and a more preferable Si content range is 0.3 to 0.6% by mass.

ＮｉとＳｉによって形成されるＮｉ−Ｓｉ系析出物はＮｉ₂Ｓｉを主体とする金属間化合物であると考えられる。ただし、合金中のＮｉおよびＳｉは時効処理によってすべてが析出物になるとは限らず、ある程度はＣｕマトリックス中に固溶した状態で存在する。固溶状態のＮｉおよびＳｉは、若干の強度上昇をもたらすものの析出状態と比べてその効果は小さく、また導電率を低下させる要因になる。このためＮｉとＳｉの含有量の比はできるだけ析出物Ｎｉ₂Ｓｉの組成比に近づけることが望ましい。したがって本発明では質量％で表したＮｉ／Ｓｉ比を３.５〜６.０の範囲に調整することが望ましく、３.５〜５.０とすることが一層好ましい。 The Ni—Si based precipitate formed by Ni and Si is considered to be an intermetallic compound mainly composed of Ni ₂ Si. However, Ni and Si in the alloy are not necessarily all precipitated by the aging treatment, and to some extent, exist in a solid solution state in the Cu matrix. Although Ni and Si in a solid solution state cause a slight increase in strength, the effect thereof is small as compared with a precipitated state, and it causes a decrease in conductivity. For this reason, it is desirable that the ratio of the Ni and Si contents be as close as possible to the composition ratio of the precipitate Ni ₂ Si. Therefore, in the present invention, it is desirable to adjust the Ni / Si ratio expressed in mass% to the range of 3.5 to 6.0, and more preferably 3.5 to 5.0.

Ｓｎは、固溶強化作用を有し、析出強化および加工硬化を組み合わせると効果的である。その作用を十分に発揮させるには、０.１質量％以上のＳｎ含有量を確保することが望ましい。ただし、Ｓｎ含有量が１.０質量％を超えると導電率が著しく低下してしまう。このため、Ｓｎを添加する場合は１.０質量％以下の範囲で行う。   Sn has a solid solution strengthening action, and is effective when combined with precipitation strengthening and work hardening. In order to fully exhibit the action, it is desirable to secure an Sn content of 0.1% by mass or more. However, when Sn content exceeds 1.0 mass%, electrical conductivity will fall remarkably. For this reason, when adding Sn, it carries out in the range of 1.0 mass% or less.

Ｍｇは、Ｎｉ−Ｓｉ系析出物の粗大化を防止する作用を有する。また、耐応力緩和性を向上させる作用も有する。これらの作用を十分に発揮させるには０.０１質量％以上のＭｇ含有量を確保することが望ましい。ただし、Ｍｇ含有量が０.３質量％を超えると鋳造性、熱間加工性が著しく低下し、問題となりやすい。このため、Ｍｇを添加する場合は０.３質量％以下の範囲で行う。   Mg has an effect of preventing the coarsening of Ni—Si based precipitates. It also has an effect of improving stress relaxation resistance. In order to fully exhibit these actions, it is desirable to secure an Mg content of 0.01% by mass or more. However, if the Mg content exceeds 0.3% by mass, the castability and hot workability are remarkably lowered, which tends to cause a problem. For this reason, when adding Mg, it carries out in the range of 0.3 mass% or less.

その他の元素として、必要に応じてＺｎ、Ｃｏ、Ｃｒ、Ｂ、Ｆｅ、Ｚｒ、Ｔｉ、Ｍｎ等を含有させることができる。例えば、Ｚｎ、Ｃｏ、Ｃｒ、Ｂ、Ｆｅ、Ｚｒ、Ｔｉ、Ｍｎは合金強度をさらに高め、かつ応力緩和を小さくする作用を有する。Ｃｏ、Ｃｒ、Ｚｒ、Ｔｉ、Ｍｎは不可避的不純物として存在するＳ、Ｐｂなどと高融点化合物を形成しやすく、また、Ｂ、Ｚｒ、Ｔｉは鋳造組織の微細化効果を有し、熱間加工性の改善に寄与しうる。   As other elements, Zn, Co, Cr, B, Fe, Zr, Ti, Mn and the like can be contained as necessary. For example, Zn, Co, Cr, B, Fe, Zr, Ti, and Mn have the effect of further increasing the alloy strength and reducing the stress relaxation. Co, Cr, Zr, Ti, and Mn are easy to form a high melting point compound with S, Pb, etc. present as inevitable impurities, and B, Zr, and Ti have the effect of refining the cast structure, It can contribute to improvement of sex.

Ｚｎ、Ｃｏ、Ｃｒ、Ｂ、Ｆｅ、Ｚｒ、Ｔｉ、Ｍｎの１種または２種以上を含有させる場合は、各元素の作用を十分に得るためにこれらの総量が０.０１質量％以上となるように含有させることが望ましい。ただし、総量が３質量％を超えると熱間または冷間加工性が低下する場合がある。また、経済的にも不利になる。したがって、その総量は３質量％以下の範囲とすることが望ましく、２質量％以下の範囲がより好ましく、１質量％以下の範囲がより一層好ましく、０.５質量％以下の範囲がさらに一層好ましい。   When one or more of Zn, Co, Cr, B, Fe, Zr, Ti, and Mn are contained, the total amount of these elements becomes 0.01% by mass or more in order to sufficiently obtain the action of each element. It is desirable to contain. However, when the total amount exceeds 3% by mass, hot workability or cold workability may be deteriorated. It is also economically disadvantageous. Accordingly, the total amount is preferably in the range of 3% by mass or less, more preferably in the range of 2% by mass or less, still more preferably in the range of 1% by mass or less, and still more preferably in the range of 0.5% by mass or less. .

〔結晶方位〕
本発明のＣｕ−Ｎｉ−Ｓｉ系銅合金は、ＬＤの方がＴＤより引張強さが高く曲げ加工性が低い｛１００｝＜００１＞を主方位成分とする再結晶集合組織から、ＴＤの方がＬＤより引張強さが高く曲げ加工性が低い｛１１０｝＜１１２＞を主方位成分とする圧延晶集合組織を発達させていくことにより、両者の中間的な組織状態を実現し、それによってＬＤとＴＤの「引張強さの差」および「曲げ加工性の差」を小さくする。発明者らは種々検討の結果、その中間的な組織状態は、仕上げ冷間圧延を伴う銅合金板材の製造工程を採用する場合、下記（１）式および（２）式によって表すことができることを見出した。 (Crystal orientation)
In the Cu—Ni—Si based copper alloy of the present invention, the LD has a higher tensile strength than the TD and a lower bending workability. From the recrystallized texture having {100} <001> as the main orientation component, the TD Has developed a rolled crystal texture whose main orientation component is {110} <112>, which has higher tensile strength and lower bending workability than LD, thereby realizing an intermediate structure state between the two. Decrease “difference in tensile strength” and “difference in bending workability” between LD and TD. As a result of various studies, the inventors have shown that the intermediate structure state can be expressed by the following formulas (1) and (2) when adopting a manufacturing process of a copper alloy sheet with finish cold rolling. I found it.

３.０≦Ｉ｛２２０｝／Ｉ₀｛２２０｝≦６.０ ……（１）
１.５≦Ｉ｛２００｝／Ｉ₀｛２００｝≦２.５ ……（２）
ここで、
Ｉ｛２２０｝：当該銅合金板材の板面における｛２２０｝結晶面のＸ線回折強度、
Ｉ｛２００｝：当該銅合金板材の板面における｛２００｝結晶面のＸ線回折強度、
Ｉ₀｛２２０｝：純銅標準粉末の｛２２０｝結晶面のＸ線回折強度、
Ｉ₀｛２００｝：純銅標準粉末の｛２００｝結晶面のＸ線回折強度、
である。ただし、Ｘ線回折試験の条件は、当該銅合金板材と純銅標準粉末とで同一とする。 3.0 ≦ I {220} / I ₀ {220} ≦ 6.0 (1)
1.5 ≦ I {200} / I ₀ {200} ≦ 2.5 (2)
here,
I {220}: X-ray diffraction intensity of {220} crystal plane in the plate surface of the copper alloy sheet,
I {200}: X-ray diffraction intensity of {200} crystal plane in the plate surface of the copper alloy sheet,
I ₀ {220}: X-ray diffraction intensity of {220} crystal plane of pure copper standard powder,
I ₀ {200}: X-ray diffraction intensity of {200} crystal plane of pure copper standard powder,
It is. However, the conditions of the X-ray diffraction test are the same for the copper alloy sheet and the pure copper standard powder.

Ｉ｛２２０｝／Ｉ₀｛２２０｝が小さすぎる場合は加工硬化不足によりＬＤ、ＴＤともに十分な強度が得られにくい。Ｉ｛２２０｝／Ｉ₀｛２２０｝が大きすぎる場合やＩ｛２００｝／Ｉ₀｛２００｝が小さすぎる場合は｛１１０｝＜１１２＞を主方位成分とする圧延晶集合組織の持つ性質が相対的に優勢であり、従来材のようにＴＤの強度が高く曲げ加工性が悪いという異方性が生じる。Ｉ｛２００｝／Ｉ₀｛２００｝が大きすぎると｛１００｝＜００１＞を主方位成分とする再結晶集合組織の持つ性質が相対的に優勢であり、ＬＤの強度が高く曲げ加工性が悪いという異方性が生じる。 When I {220} / I ₀ {220} is too small, it is difficult to obtain sufficient strength for both LD and TD due to insufficient work hardening. When I {220} / I ₀ {220} is too large or I {200} / I ₀ {200} is too small, the properties of the rolled crystal texture having {110} <112> as the main orientation component are present. It is relatively dominant, and anisotropy occurs in which the strength of TD is high and bending workability is poor as in the case of conventional materials. If I {200} / I ₀ {200} is too large, the properties of the recrystallized texture having {100} <001> as the main orientation component are relatively dominant, the strength of the LD is high, and the bending workability is high. Anisotropy of bad occurs.

上記（１）式に替えて下記（１）’式を満たすことがより好ましく、下記（１）’’式を満たすことが一層好ましい。
３.０＜Ｉ｛２２０｝／Ｉ₀｛２２０｝≦６.０ ……（１）’
３.５≦Ｉ｛２２０｝／Ｉ₀｛２２０｝≦５.５ ……（１）’’
また、上記（２）式に替えて下記(２）’式を満たすことがより好ましい。
１.６≦Ｉ｛２００｝／Ｉ₀｛２００｝≦２.３ ……（２）’ It is more preferable to satisfy the following expression (1) ′ instead of the above expression (1), and it is even more preferable to satisfy the following expression (1) ″.
3.0 <I {220} / I ₀ {220} ≦ 6.0 (1) ′
3.5 ≦ I {220} / I ₀ {220} ≦ 5.5 (1) ″
It is more preferable to satisfy the following expression (2) ′ instead of the above expression (2).
1.6 ≦ I {200} / I ₀ {200} ≦ 2.3 (2) ′

〔特性〕
電気・電子部品の更なる小型化、薄肉化に対応するには、素材である銅合金板材の引張強さはＬＤ、ＴＤいずれにおいても７００ＭＰａ以上であることが好ましく、７２０ＭＰａ以上であることが一層好ましい。曲げ加工性はＬＤ、ＴＤいずれにおいても９０°Ｗ曲げ試験における最小曲げ半径Ｒと板厚ｔの比Ｒ／ｔが１.０以下であることが好ましく、０.８以下であることが一層好ましい。 〔Characteristic〕
In order to cope with further downsizing and thinning of electric / electronic parts, the tensile strength of the copper alloy sheet material is preferably 700 MPa or more in both LD and TD, and more preferably 720 MPa or more. preferable. For both LD and TD, the ratio R / t of the minimum bending radius R to the sheet thickness t in the 90 ° W bending test is preferably 1.0 or less, and more preferably 0.8 or less. .

さらに、異方性に関しては、部品に加工する際の設計自由度の拡大等を考慮すると、引張強さのＬＤとＴＤの差の絶対値が３０ＭＰａ以下であることが好ましく、２０ＭＰａ以下であることがより好ましく、１５ＭＰａ以下であることが一層好ましい。また、９０°Ｗ曲げ試験での最小曲げ半径Ｒと板厚ｔの比Ｒ／ｔのＬＤとＴＤの差の絶対値が０.５以下であることが好ましく、０.３以下であることが一層好ましい。   Furthermore, regarding the anisotropy, in consideration of the expansion of design freedom when processing into a part, the absolute value of the difference between the tensile strength LD and TD is preferably 30 MPa or less, and 20 MPa or less. Is more preferable, and it is still more preferable that it is 15 MPa or less. Further, the absolute value of the difference between LD and TD in the ratio R / t of the minimum bending radius R to the sheet thickness t in the 90 ° W bending test is preferably 0.5 or less, and is 0.3 or less. Even more preferred.

〔製造工程〕
以上のような本発明の銅合金板材は、例えば以下のような製造工程により作ることができる。
「溶解・鋳造→熱間圧延→冷間圧延→溶体化処理→時効処理→仕上げ冷間圧延→加熱処理」
ただし、製造条件のコントロールが必要である。上記工程中には記載していないが、熱間圧延後には必要に応じて面削が行われ、熱処理後には必要に応じて酸洗、研磨、あるいはさらに脱脂が行われる。以下、各工程について説明する。 〔Manufacturing process〕
The copper alloy sheet material of the present invention as described above can be produced, for example, by the following manufacturing process.
“Melting / Casting → Hot Rolling → Cold Rolling → Solution Treatment → Aging Treatment → Finish Cold Rolling → Heat Treatment”
However, it is necessary to control the manufacturing conditions. Although not described in the above steps, chamfering is performed as necessary after hot rolling, and pickling, polishing, or further degreasing is performed as necessary after heat treatment. Hereinafter, each step will be described.

〔溶解・鋳造〕
一般的な銅合金の溶製方法に従うことができる。連続鋳造、半連続鋳造等により鋳片を製造すればよい。 [Melting / Casting]
A general copper alloy melting method can be followed. The slab may be manufactured by continuous casting, semi-continuous casting, or the like.

〔熱間圧延〕
鋳片を熱間加工することで鋳造過程で生じる晶出相を消失させると同時に、再結晶によって鋳造組織を破壊し再結晶粒組織の均一化を図る。この熱間圧延は析出物の固溶温度域で行うことが望ましい。熱間圧延終了後は直ちに水冷等により急冷することが望ましい。６５０℃未満の温度域ではＮｉとＳｉの粗大な化合物の生成により熱間割れが生じやすくなるので９５０〜６５０℃の範囲で熱間圧延を行い、最終パス終了後に水冷することが好ましい。熱間圧延率は概ね６５〜９０％とすればよい。熱間加工後は必要に応じて面削や酸洗を行うことができる。 (Hot rolling)
By hot working the slab, the crystallization phase generated in the casting process disappears, and at the same time, the cast structure is destroyed by recrystallization to make the recrystallized grain structure uniform. This hot rolling is desirably performed in the solid solution temperature range of the precipitate. It is desirable to quench immediately after the hot rolling by water cooling or the like. In the temperature range below 650 ° C., hot cracking is likely to occur due to the formation of a coarse compound of Ni and Si. Therefore, it is preferable to perform hot rolling in the range of 950 to 650 ° C. and water-cool after the final pass. The hot rolling rate may be approximately 65 to 90%. After hot working, chamfering or pickling can be performed as necessary.

〔冷間圧延〕
溶体化処理前に行う冷間圧延では圧延率を６０％以上確保する。このような高い圧延率で加工された材料に対し、次工程で溶体化処理を施すことにより、｛１００｝＜００１＞を主方位成分とする再結晶集合組織を得ることができる。この冷間圧延率が低すぎると上記再結晶集合組織の形成が不十分となり、本発明の目的を達成することが難しくなる。すなわち、再結晶集合組織は再結晶前の冷間圧延率に依存する。具体的には、｛１００｝＜００１＞の方位関係を持つ溶体化処理後の結晶配向は、冷間圧延率が６０％未満の場合には十分生成しない。冷間圧延率が６０％以上になると冷間圧延率の増加に伴って溶体化処理後の上記結晶配向は増大し、冷間圧延率が約８０％を超えると急激な増加に転じる。上記方位関係が十分に優勢な結晶配向を得るには冷間圧延率を６０％以上とする必要があり、８５％以上とすることがより効果的である。９０％以上とすることが一層好ましい。なお、冷間圧延率の上限はミルパワー等により必然的に制約を受けるので、特に規定する必要はないが、概ね９８％以下で良好な結果を得やすい。
熱間圧延後、溶体化処理前に、中間焼鈍を挟んで複数回の冷間圧延を実施する場合は、溶体化処理の直前に行われる冷間圧延での冷間圧延率を上記のように調整する。 (Cold rolling)
In the cold rolling performed before the solution treatment, a rolling rate of 60% or more is secured. A recrystallized texture having {100} <001> as the main orientation component can be obtained by subjecting the material processed at such a high rolling ratio to a solution treatment in the next step. If this cold rolling rate is too low, the formation of the recrystallized texture becomes insufficient, making it difficult to achieve the object of the present invention. That is, the recrystallization texture depends on the cold rolling rate before recrystallization. Specifically, the crystal orientation after the solution treatment having an orientation relationship of {100} <001> is not sufficiently generated when the cold rolling rate is less than 60%. When the cold rolling rate reaches 60% or more, the crystal orientation after the solution treatment increases with an increase in the cold rolling rate, and when the cold rolling rate exceeds about 80%, it starts to increase rapidly. In order to obtain a crystal orientation in which the orientation relationship is sufficiently dominant, it is necessary to set the cold rolling rate to 60% or more, and it is more effective to set it to 85% or more. More preferably, it is 90% or more. The upper limit of the cold rolling rate is inevitably restricted by the mill power or the like, so it is not necessary to define it in particular, but good results are likely to be obtained at approximately 98% or less.
After hot rolling and before solution treatment, when performing cold rolling multiple times with intermediate annealing, the cold rolling rate in cold rolling performed immediately before solution treatment is as described above. adjust.

〔溶体化処理〕
ここでの溶体化処理は、「溶質元素のマトリックス中への再固溶」および「再結晶化」という２つの目的を兼ねる熱処理である。上記のように高い圧延率で加工された材料を対象としていることから、溶体化処理後には｛１００｝＜００１＞を優先方位とする再結晶集合組織が得られる。この溶体化処理は、再結晶粒径が１５〜６０μｍとなるように温度・時間を調整して行うことが望ましく、２０超え〜４０μｍ、あるいはさらに２５超え〜４０μｍとなるように調整することが一層好ましい。再結晶粒径が微細になりすぎると再結晶集合組織が弱くなりことにより、仕上げ圧延時時に圧延集合組織が優勢となりやすく、異方性の改善が難しくなる。具体的には、７００〜８００℃×１０ｓｅｃ〜１０ｍｉｎの加熱条件が採用できる。温度が低すぎると再結晶は不完全で溶質元素の固溶も不十分となり、温度が高すぎると結晶粒が粗大化してしまう。このような場合、最終的に異方性の少ない高強度材を得ることは困難である。 [Solution treatment]
The solution treatment here is a heat treatment that serves the two purposes of “re-solution of solute elements in the matrix” and “recrystallization”. Since the target is a material processed at a high rolling rate as described above, a recrystallized texture having {100} <001> as the preferred orientation is obtained after the solution treatment. This solution treatment is desirably performed by adjusting the temperature and time so that the recrystallized grain size is 15 to 60 μm, and further adjusting to be 20 to 40 μm, or further 25 to 40 μm. preferable. If the recrystallized grain size becomes too fine, the recrystallized texture becomes weak, so that the rolled texture tends to become dominant during finish rolling, and it becomes difficult to improve anisotropy. Specifically, heating conditions of 700 to 800 ° C. × 10 sec to 10 min can be employed. If the temperature is too low, the recrystallization is incomplete and the solute elements are not sufficiently dissolved, and if the temperature is too high, the crystal grains become coarse. In such a case, it is difficult to finally obtain a high strength material with little anisotropy.

〔時効処理〕
溶体化処理に引き続き、時効処理を施す。Ｃｕ−Ｎｉ−Ｓｉ系合金の一般的な製造法では、溶体化処理後に中間での冷間圧延を施し、その後、時効処理を施す工程がしばしば採用される。この場合、その中間での冷間圧延によって圧延集合組織が発達していくので、時効処理後の引張強さはＬＤとＴＤで同等になるか、あるいはＴＤの方が大きくなる。ところが、時効処理前に行う冷間圧延は、時効処理後に行う冷間圧延より強度の向上効果が小さい。このため、例えば引張強さが７００ＭＰａ以上といった高強度材を得るには、時効処理前に冷間圧延を行ったとしても、更に時効処理後に仕上げ冷間圧延を施す必要が生じる。そうすると、結局その仕上げ冷間圧延によって異方性が生じてしまう。したがって、本発明の銅合金板材を得るためには、溶体化処理後に中間の冷間圧延を行わず、直接時効処理に供する。この時効処理前の冷間圧延を省略することは生産性の向上の点でも有利である。 [Aging treatment]
An aging treatment is performed following the solution treatment. In a general manufacturing method of a Cu—Ni—Si based alloy, a step of performing an intermediate cold rolling after a solution treatment and then an aging treatment is often employed. In this case, since the rolling texture is developed by cold rolling in the middle, the tensile strength after the aging treatment is equal between LD and TD, or TD is larger. However, the cold rolling performed before the aging treatment is less effective in improving the strength than the cold rolling performed after the aging treatment. For this reason, for example, in order to obtain a high strength material having a tensile strength of 700 MPa or more, even if cold rolling is performed before the aging treatment, it is necessary to perform finish cold rolling after the aging treatment. If it does so, anisotropy will arise by the finish cold rolling after all. Therefore, in order to obtain the copper alloy sheet material of the present invention, it is directly subjected to an aging treatment without performing intermediate cold rolling after the solution treatment. Omitting the cold rolling before the aging treatment is also advantageous in terms of improving productivity.

時効処理では、当該合金の導電性と強度の向上に有効な条件の中で、あまり温度を上げすぎないようにする。時効処理温度が高温になると溶体化処理によって発達させた｛１００｝＜００１＞を優先方位とする結晶配向が弱められ、結果的に十分な異方性改善効果が得られない場合がある。具体的には４００〜５００℃で行うことが望ましく、４２０〜４８０℃とすることがより好ましい。時効処理時間は概ね１〜１０ｈ程度で良好な結果が得られる。   In the aging treatment, the temperature is not excessively raised under conditions effective for improving the conductivity and strength of the alloy. When the aging treatment temperature becomes high, the crystal orientation with {100} <001> developed by solution treatment as the preferred orientation is weakened, and as a result, a sufficient anisotropy improving effect may not be obtained. Specifically, it is desirable to carry out at 400-500 degreeC, and it is more preferable to set it as 420-480 degreeC. An aging treatment time is about 1 to 10 hours, and good results are obtained.

〔仕上げ冷間圧延〕
以上の工程により、板材の集合組織は｛１００｝＜００１＞を主方位成分とするものになっており、引張強さはＬＤの方が大きい状態になっている。この仕上げ冷間圧延では、強度レベルの向上を図るとともに、｛１１０｝＜１１２＞方位の圧延集合組織を発達させていく。仕上げ冷間圧延の圧延率が低すぎると強度上昇効果が十分に得られず、逆に圧延率が高すぎると｛１１０｝＜１１２＞方位の圧延集合組織が優勢となって、異方性の相殺された中間的な結晶配向が実現できない。種々検討の結果、仕上げ圧延率は１０〜６５％の範囲とする必要があるが、２５〜６０％の範囲がより好ましい。通常、３０〜５０％程度で良好な結果が得られやすい。
最終的な板厚としては概ね０.１〜１.０ｍｍが適用され、０.１〜０.５ｍｍとすることが一層好ましい。 (Finish cold rolling)
Through the above steps, the texture of the plate material has {100} <001> as the main orientation component, and the tensile strength of LD is larger. In this finish cold rolling, the strength level is improved and a rolling texture of {110} <112> orientation is developed. If the rolling rate of the finish cold rolling is too low, the effect of increasing the strength cannot be sufficiently obtained. Conversely, if the rolling rate is too high, the rolling texture of the {110} <112> orientation becomes dominant and the anisotropic An offset intermediate crystal orientation cannot be realized. As a result of various studies, the finish rolling ratio needs to be in the range of 10 to 65%, but more preferably in the range of 25 to 60%. Usually, good results are easily obtained at about 30 to 50%.
The final plate thickness is generally about 0.1 to 1.0 mm, and more preferably 0.1 to 0.5 mm.

〔加熱処理（低温焼鈍）〕
仕上げ冷間圧延後には、板条材の残留応力の低減、ばね限界値と耐応力緩和特性向上を目的として、低温焼鈍を施すことができる。加熱温度は２５０〜５００℃とすることが望ましい。これにより板材内部の残留応力が低減され、強度低下をほとんど伴わずに曲げ加工性と破断伸びを上昇させることができる。また、導電率を上昇させることもできる。この加熱温度が高すぎると短時間で軟化し、バッチ式でも連続式でも特性のバラツキが生じやすくなる。逆に加熱温度が低すぎると上記特性の改善効果が十分に得られない。加熱時間は５ｓｅｃ以上確保することが望ましく、通常１ｈ以内の範囲で良好な結果が得られる。 [Heat treatment (low temperature annealing)]
After the finish cold rolling, low-temperature annealing can be performed for the purpose of reducing the residual stress of the strip material and improving the spring limit value and stress relaxation resistance. The heating temperature is preferably 250 to 500 ° C. As a result, the residual stress inside the plate material is reduced, and bending workability and elongation at break can be increased with almost no decrease in strength. In addition, the conductivity can be increased. If this heating temperature is too high, it softens in a short time, and variations in characteristics are likely to occur in both batch and continuous systems. Conversely, if the heating temperature is too low, the effect of improving the above characteristics cannot be obtained sufficiently. It is desirable to secure a heating time of 5 sec or more, and good results are usually obtained within a range of 1 h.

表１に示す銅合金を溶製し、縦型連続鋳造機を用いて鋳造した。得られた鋳片を９５０℃に加熱し、９５０〜６５０℃の温度範囲で熱間圧延を行うことにより厚さ１０ｍｍの板にし、その後急冷（水冷）した。熱間圧延後、表層の酸化層を機械研磨により除去（面削）した。次いで、種々の圧延率で冷間圧延を行った後、溶体化処理を施した。溶体化処理では圧延板表面を研磨・エッチングした面における平均結晶粒径（ＪＩＳ Ｈ０５０１の線分法）が２５μｍ超え〜４０μｍとなるように保持温度を合金組成に応じて７００〜８００℃の範囲内で調整した。保持時間は１０ｓｅｃ〜１０ｍｉｎの範囲とした。続いて、上記溶体化処理後の板材に対して時効処理を施した。時効処理温度は４５０℃とし、時効時間は合金組成に応じて４５０℃の時効で硬さがピークになる時間に調整した。このような合金組成に応じて最適な溶体化処理条件や時効処理時間は予備実験により把握してある。次いで、種々の圧延率で仕上げ冷間圧延を行い、その後、４００℃×５ｍｉｎの加熱処理（低温焼鈍）を行うことによって供試材を得た。なお、必要に応じて途中で面削を行い、供試材の板厚は０.２ｍｍに揃えた。   The copper alloys shown in Table 1 were melted and cast using a vertical continuous casting machine. The obtained slab was heated to 950 ° C., and hot-rolled in a temperature range of 950 to 650 ° C. to obtain a plate having a thickness of 10 mm, and then rapidly cooled (water cooled). After hot rolling, the surface oxide layer was removed (faced) by mechanical polishing. Next, after cold rolling at various rolling rates, solution treatment was performed. In the solution treatment, the holding temperature is in the range of 700 to 800 ° C. depending on the alloy composition so that the average crystal grain size (line segment method of JIS H0501) on the polished and etched surface of the rolled plate exceeds 25 μm to 40 μm. Adjusted. The holding time was in the range of 10 sec to 10 min. Subsequently, an aging treatment was performed on the plate material after the solution treatment. The aging treatment temperature was 450 ° C., and the aging time was adjusted to a time when the hardness peaked at 450 ° C. according to the alloy composition. The optimum solution treatment conditions and aging treatment time according to such an alloy composition have been grasped by preliminary experiments. Next, finish cold rolling was performed at various rolling rates, and then heat treatment (low temperature annealing) at 400 ° C. × 5 min was performed to obtain a test material. If necessary, chamfering was performed in the middle, and the thickness of the specimen was adjusted to 0.2 mm.

各供試材から試料を採取し、Ｘ線回折強度、導電率、引張強さ、破断伸び、曲げ加工性を以下の方法で調べた。   Samples were collected from each test material, and X-ray diffraction strength, electrical conductivity, tensile strength, elongation at break, and bending workability were examined by the following methods.

〔Ｘ線回折強度〕
Ｘ線回折装置（ＸＲＤ）を用いて、Ｍｏ−Ｋα線、管電圧２０ｋＶ、管電流２ｍＡの条件で、供試材の板面（圧延面）および無方向性試料（純銅標準粉末）について｛２２０｝面および｛２００｝面の反射回折面強度を測定し、前記（１）式中および（２）式中に示されるＸ線回折強度比を求めた。 [X-ray diffraction intensity]
Using an X-ray diffractometer (XRD), the plate surface (rolled surface) and non-directional sample (pure copper standard powder) of the test material under the conditions of Mo-Kα ray, tube voltage 20 kV, tube current 2 mA {220 } And {200} plane reflection diffraction surface intensities were measured, and X-ray diffraction intensity ratios shown in the above formulas (1) and (2) were determined.

〔導電率〕
ＪＩＳ Ｈ０５０５に従って各供試材の導電率を測定した。
〔引張強さ、破断伸び〕
各供試材からＬＤおよびＴＤの引張試験片（ＪＩＳ ５号）を採取し、各方向ｎ＝３でＪＩＳ Ｚ２２４１に準拠した引張試験行い、ｎ＝３の平均値によってＬＤの引張強さσ_LD、ＴＤの引張強さσ_TD、ＬＤの破断伸びε_LD、ＴＤの破断伸びε_TDを求めた。また、ＬＤとＴＤの引張強さの差の絶対値｜σ_LD−σ_TD｜を算出した。 〔conductivity〕
The electrical conductivity of each test material was measured according to JIS H0505.
[Tensile strength, elongation at break]
LD and TD tensile test specimens (JIS No. 5) were taken from each sample material, subjected to a tensile test according to JIS Z2241 in each direction n = 3, and the tensile strength σ _{LD of LD according} to the average value of n = 3 , TD tensile strength σ _TD , LD breaking elongation ε _LD , and TD breaking elongation ε _TD were determined. Further, the absolute value | σ _LD −σ _TD | of the difference in tensile strength between LD and TD was calculated.

〔曲げ加工性〕
各供試材から長手方向がＬＤおよびＴＤの曲げ試験片（幅１０ｍｍ）を採取し、ＪＩＳ Ｈ３１１０に準拠した９０°Ｗ曲げ試験を行った。試験後の試験片について曲げ加工部の表面および断面を光学顕微鏡にて１００倍の倍率で観察することにより、割れが発生しない最小曲げ半径Ｒを求め、これを供試材の板厚ｔで除することによりＬＤ、ＴＤそれぞれのＲ／ｔ値（それぞれＲ／ｔ_LD、Ｒ／ｔ_TDと表記）を求めた。また、ＬＤとＴＤのＲ／ｔ値の差の絶対値｜Ｒ／ｔ_LD−Ｒ／ｔ_TD｜を算出した。
これらの結果を表２に示す。 [Bending workability]
Bending test pieces (width 10 mm) having a longitudinal direction of LD and TD were sampled from each test material, and a 90 ° W bending test based on JIS H3110 was performed. By observing the surface and cross section of the bent portion of the test piece after the test with an optical microscope at a magnification of 100 times, the minimum bending radius R at which no crack is generated is obtained, and this is divided by the thickness t of the specimen. Thus, R / t values of LD and TD (represented as R / t _LD and R / t _TD , respectively) were obtained. Also, the absolute value | R / t _LD −R / t _TD | of the difference between the R / t values of LD and TD was calculated.
These results are shown in Table 2.

表２から判るように、本発明例のものはいずれもＸ線回折強度比が（１）式および（２）式を満たす結晶配向を有し、引張強さがＬＤ、ＴＤとも７００ＭＰａ以上という高強度を呈するとともに、Ｒ／ｔ値がＬＤ、ＴＤとも１.０以下という優れた曲げ加工性を有する。さらに、｜σ_LD−σ_TD｜が１５ＭＰａ以下、かつ｜Ｒ／ｔ_LD−Ｒ／ｔ_TD｜が０.５以下であり、引張強さと曲げ加工性についての異方性が極めて小さい。 As can be seen from Table 2, all of the examples of the present invention have a crystal orientation in which the X-ray diffraction intensity ratio satisfies the expressions (1) and (2), and the tensile strength is as high as 700 MPa or more for both LD and TD. In addition to exhibiting strength, the R / t value has excellent bending workability of both LD and TD of 1.0 or less. Furthermore, | σ _LD −σ _TD | is 15 MPa or less, and | R / t _LD −R / t _TD | is 0.5 or less, and the anisotropy of tensile strength and bending workability is extremely small.

これに対し、比較例Ｎｏ.２１は冷間圧延率と仕上げ圧延率ともに低すぎたことにより強度レベルが低かった。Ｎｏ.２２、２３は溶体化処理前の冷間圧延率が低すぎたことにより溶体化処理で｛１００｝＜００１＞を主方位成分とする再結晶集合組織が十分に発達せず、最終的に（２）式を満たす結晶配向が得られなかった。その結果、特に曲げ加工性についての異方性が大きかった。   On the other hand, Comparative Example No. 21 had a low strength level because both the cold rolling rate and the finish rolling rate were too low. In Nos. 22 and 23, since the cold rolling ratio before the solution treatment was too low, the recrystallization texture having {100} <001> as the main orientation component was not sufficiently developed in the solution treatment, and the final No crystal orientation satisfying the formula (2) was obtained. As a result, the anisotropy was particularly great with respect to bending workability.

Ｎｏ.２４はＮｉとＳｉ含有量が低すぎ析出物の量が少なかったことにより、強度レベルが低かった。Ｎｏ.２５はＮｉとＳｉ含有量が高すぎたことにより、溶体化処理後の冷間圧延率が適正であっても（１）式と（２）式を満たす結晶配向が得られず、引張強さは高いものの異方性が大きく、またＴＤの曲げ加工性が非常に悪かった。Ｎｏ.２６はＮｉおよびＳｉ含有量がさらに高すぎたものである。溶体化処理前の冷間圧延率と仕上げ冷間圧延率を適正とすることにより（１）式と（２）式を満たす結晶配向は得られたものの、曲げ加工性がＬＤ、ＴＤとも非常に悪かった。   No. 24 had a low strength level because the contents of Ni and Si were too low and the amount of precipitates was small. In No. 25, since the Ni and Si contents were too high, even if the cold rolling rate after the solution treatment was appropriate, the crystal orientation satisfying the formulas (1) and (2) was not obtained, Although the strength was high, the anisotropy was large, and the bending workability of TD was very poor. No. 26 has a Ni and Si content that is too high. Although the crystal orientation satisfying the formulas (1) and (2) was obtained by making the cold rolling rate and the finish cold rolling rate before solution treatment appropriate, the bending workability was very good for both LD and TD. It was bad.

Ｎｏ.２７は仕上げ圧延率が低すぎたことにより（１）式と（２）式を満たす結晶配向が得られず、引張強さが非常に低く、その異方性にも劣った。Ｎｏ.２８は仕上げ圧延率が高すぎたことにより（１）式と（２）式を満たす結晶配向が得られず、ＴＤの曲げ加工性が非常に悪いとともに、引張強さおよび曲げ加工性の異方性にも劣った。   In No. 27, the finish rolling rate was too low, so that the crystal orientation satisfying the formulas (1) and (2) was not obtained, the tensile strength was very low, and the anisotropy was also inferior. In No. 28, since the finish rolling ratio was too high, crystal orientation satisfying the formulas (1) and (2) was not obtained, the bending workability of TD was very poor, and the tensile strength and bending workability were low. Also inferior in anisotropy.

Claims (7)

質量％で、Ｎｉ：０．７〜２．５％、Ｓｉ：０．２〜０．７％、残部がＣｕおよび不可避的不純物の組成を有し、引張強さが７００ＭＰａ以上であって、板面において圧延方向に対し平行方向をＬＤ、直角方向をＴＤと呼ぶとき、引張強さについてＬＤとＴＤの差の絶対値が３０ＭＰａ以下、９０°Ｗ曲げ試験での最小曲げ半径Ｒと板厚ｔの比Ｒ／ｔについてＬＤとＴＤの差の絶対値が０．５以下であり、下記（１）式および（２）式を満たす結晶配向を有する銅合金板材。
３．０≦Ｉ｛２２０｝／Ｉ₀｛２２０｝≦６．０ …… （１）
１．５≦Ｉ｛２００｝／Ｉ₀｛２００｝≦２．５ …… （２）
ここで、Ｉ｛２２０｝およびＩ｛２００｝はそれぞれ当該板材の板面における｛２２０｝結晶面および｛２００｝結晶面のＸ線回折強度であり、Ｉ₀｛２２０｝およびＩ₀｛２００｝はそれぞれ純銅標準粉末の｛２２０｝結晶面および｛２００｝結晶面のＸ線回折強度である。 In mass%, Ni: 0.7-2.5%, Si: 0.2-0.7%, the balance has the composition of Cu and inevitable impurities , the tensile strength is 700 MPa or more, In the plane, when the parallel direction to the rolling direction is called LD and the perpendicular direction is called TD, the absolute value of the difference between LD and TD in terms of tensile strength is 30 MPa or less, and the minimum bending radius R and thickness t in the 90 ° W bending test A copper alloy sheet having a crystal orientation in which the absolute value of the difference between LD and TD is 0.5 or less and the following formulas (1) and (2) are satisfied.
3.0 ≦ I {220} / I ₀ {220} ≦ 6.0 (1)
1.5 ≦ I {200} / I ₀ {200} ≦ 2.5 (2)
Here, I {220} and I {200} are the X-ray diffraction intensities of the {220} crystal plane and {200} crystal plane on the plate surface of the plate, respectively, and I ₀ {220} and I ₀ {200}. Are the X-ray diffraction intensities of the {220} crystal plane and {200} crystal plane of pure copper standard powder, respectively. 質量％で、Ｎｉ：０．７〜２．５％、Ｓｉ：０．２〜０．７％、残部がＣｕおよび不可避的不純物の組成を有し、引張強さが７００ＭＰａ以上、９０°Ｗ曲げ試験での最小曲げ半径Ｒと板厚ｔの比Ｒ／ｔが１以下であって、板面において圧延方向に対し平行方向をＬＤ、直角方向をＴＤと呼ぶとき、引張強さについてＬＤとＴＤの差の絶対値が３０ＭＰａ以下、前記Ｒ／ｔについてＬＤとＴＤの差の絶対値が０．５以下であり、下記（１）式および（２）式を満たす結晶配向を有する銅合金板材。
３．０≦Ｉ｛２２０｝／Ｉ₀｛２２０｝≦６．０ …… （１）
１．５≦Ｉ｛２００｝／Ｉ₀｛２００｝≦２．５ …… （２）
ここで、Ｉ｛２２０｝およびＩ｛２００｝はそれぞれ当該板材の板面における｛２２０｝結晶面および｛２００｝結晶面のＸ線回折強度であり、Ｉ₀｛２２０｝およびＩ₀｛２００｝はそれぞれ純銅標準粉末の｛２２０｝結晶面および｛２００｝結晶面のＸ線回折強度である。 In mass%, Ni: 0.7-2.5%, Si: 0.2-0.7%, the balance is Cu and inevitable impurities , tensile strength is 700 MPa or more, 90 ° W bending When the ratio R / t of the minimum bending radius R to the sheet thickness t in the test is 1 or less, the parallel direction to the rolling direction on the plate surface is called LD, and the perpendicular direction is called TD, the tensile strength is expressed as LD and TD. A copper alloy sheet material having an absolute value of difference of 30 MPa or less, an absolute value of difference of LD and TD of R / t of 0.5 or less, and a crystal orientation satisfying the following formulas (1) and (2).
3.0 ≦ I {220} / I ₀ {220} ≦ 6.0 (1)
1.5 ≦ I {200} / I ₀ {200} ≦ 2.5 (2)
Here, I {220} and I {200} are the X-ray diffraction intensities of the {220} crystal plane and {200} crystal plane on the plate surface of the plate, respectively, and I ₀ {220} and I ₀ {200}. Are the X-ray diffraction intensities of the {220} crystal plane and {200} crystal plane of pure copper standard powder, respectively. さらにＳｎ：１．０％以下を含む組成を有する請求項１または２に記載の銅合金板材。   Furthermore, the copper alloy sheet | seat material of Claim 1 or 2 which has a composition containing Sn: 1.0% or less. さらにＭｇ：０．３％以下を含む組成を有する請求項１〜３のいずれかに記載の銅合金板材。   Furthermore, Mg: The copper alloy board | plate material in any one of Claims 1-3 which has a composition containing 0.3% or less. さらにＺｎ、Ｃｏ、Ｃｒ、Ｂ、Ｆｅ、Ｚｒ、Ｔｉ、Ｍｎの１種以上を合計３％以下の範囲で含む組成を有する請求項１〜４のいずれかに記載の銅合金板材。   Furthermore, the copper alloy board | plate material in any one of Claims 1-4 which has a composition which contains 1 or more types of Zn, Co, Cr, B, Fe, Zr, Ti, and Mn in the range of 3% or less in total. 組成調整された銅合金材料に対し、６０％以上の冷間圧延、再結晶粒径２５超え〜４０μｍとする溶体化処理、４００〜５００℃の時効処理、２５〜６０％の仕上げ冷間圧延、２５０〜５００℃の加熱処理を順次施す工程を有する請求項１〜５のいずれかに記載の銅合金板材の製造法。 60% or more of cold-rolled composition-adjusted copper alloy material, solution treatment with recrystallized grain size exceeding 25 to 40 μm , aging treatment at 400 to 500 ° C., finish cold rolling at 25 to 60% , The method for producing a copper alloy sheet according to any one of claims 1 to 5, further comprising a step of sequentially performing a heat treatment at 250 to 500 ° C. 組成調整された銅合金材料に対し、６０％以上の冷間圧延、再結晶粒径２５超え〜４０μｍとする溶体化処理、４００〜５００℃の時効処理、２５〜６０％で結晶配向を調整する仕上げ冷間圧延、２５０〜５００℃の加熱処理を順次施す工程を有する請求項１〜５のいずれかに記載の銅合金板材の製造法。 60% or more cold rolling, recrystallization grain size 25 to 40 μm solution treatment, aging treatment at 400 to 500 ° C. , crystal orientation adjusted at 25 to 60% for the copper alloy material whose composition is adjusted The manufacturing method of the copper alloy sheet | seat material in any one of Claims 1-5 which has the process of performing a finish cold rolling and heat processing of 250-500 degreeC sequentially.