JP2006009137A - Copper alloy - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a copper alloy having excellent strength, electrical conductivity, bending workability or the like as the material for a terminal, a connector, a switch or the like. <P>SOLUTION: The copper alloy for electronic machinery and tools having excellent bending workability contains Ni 2.0 to 4.5 mass%, and Si 0.3 to 1.0 mass%, with the balance being Cu and unavoidable impurities, which satisfies the following expression: Iä311}×A/(Iä311}+Iä220}+Iä200})<1.5 wherein Iä311} represents an X-ray diffraction intensity from a ä311} plane at a sheet surface; Iä220} represents an X-ray diffraction intensity from a ä220} plane at the sheet surface; Iä200} represents an X-ray diffraction intensity from a ä200} plane at the sheet surface; and A (μm) represents a crystalline grain size. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a high-strength copper alloy suitable as a material for terminals, connectors, switches, and the like.

  With the recent miniaturization and high performance of electrical and electronic equipment, more stringent improvements in characteristics have been demanded for materials such as connectors used there. Specifically, for example, the thickness of the plate material used for the spring contact portion of the connector has become very thin, and it has become difficult to ensure the contact pressure. That is, in the spring contact portion of the connector, the plate material (spring material) is usually bent, and the contact pressure necessary for electrical connection is obtained by the reaction force, but the same contact pressure is obtained when the plate material is thinned. In order to obtain it, it is necessary to increase the amount of bending, and in this case, the plate material may be plastically deformed beyond the elastic limit. For this reason, the plate material is required to further improve the elastic limit.

  In addition, the material of the spring contact portion of the connector is required to have various characteristics such as stress relaxation characteristics, thermal conductivity, bending workability, heat resistance, plating adhesion, and migration characteristics. Among them, strength, stress relaxation characteristics, thermal / electrical conductivity, and bending workability are important. By the way, phosphor bronze has been conventionally used in a large amount for the spring contact portion of the connector. However, phosphor bronze cannot completely satisfy the above requirements, and in recent years it has higher strength and stress relaxation characteristics. The switch to low beryllium copper (JIS-C1753 alloy), which is excellent and has good conductivity, is in progress.

  In addition, there is an example of a Cu—Ni—Si alloy having relatively high strength as a material having characteristics equivalent to that of low beryllium copper and being inexpensive and high in safety (for example, Patent Document 1). Furthermore, the contact part material includes an example of a copper alloy in which the stress relaxation characteristics of the Cu—Ni—Si based alloy are improved by adding Mg (for example, Patent Document 2). There is also an example of a copper alloy having a strength equivalent to low beryllium copper by increasing the concentration of Ni and Si in the Cu—Ni—Si alloy (see, for example, Patent Document 3).

  However, there is a problem that low beryllium copper is very expensive and metal beryllium is toxic. Therefore, attempts have been made to increase the strength of Cu-Ni-Si alloys. However, if the concentration of Ni and Si is excessively high, bending workability, which is one of the required characteristics of the connector, deteriorates. This limits the use of connectors that can be used. Specifically, when bending is performed, grain boundary embrittlement cracking occurs and bending workability is reduced. Therefore, no Cu-Ni-Si-based alloy has ever been comparable in strength, conductivity, and bending workability to low beryllium copper, and the stress relaxation properties do not reach that of low beryllium copper even when Mg is added. .

JP-A 63-130739 JP-A-5-59468 JP 2002-180161 A

  An object of the present invention is to provide a copper alloy having good strength, conductivity, bending workability, stress relaxation characteristics, plating adhesion, and the like as materials for terminals, connectors, switches, and the like.

The object of the present invention is realized by the following means.
[1] A copper alloy containing 2.0 to 4.5% by mass of Ni and 0.3 to 1.0% by mass of Si, with the balance being Cu and inevitable impurities, from the {311} plane on the plate surface X-ray diffraction intensity is I {311}, diffraction intensity from the {220} plane is I {220}, diffraction intensity from the {200} plane is I {200}, and crystal grain size is A (μm) The copper alloy for electronic devices excellent in bending workability characterized by satisfy | filling following formula (1).
I {311} × A / (I {311} + I {220} + I {200}) <1.5 (1)
[2] Copper alloy comprising 2.0 to 4.5% by mass of Ni, 0.3 to 1.0% by mass of Si, S exceeding 0 and less than 0.005% by mass, the balance being Cu and inevitable impurities The X-ray diffraction intensity from the {311} plane on the plate surface is I {311}, the diffraction intensity from the {220} plane is I {220}, and the diffraction intensity from the {200} plane is I {200}. A copper alloy for electronic equipment having excellent bending workability, characterized by satisfying the following formula (1) when the crystal grain size is A (μm).
I {311} × A / (I {311} + I {220} + I {200}) <1.5 (1)
[3] The copper alloy according to [1] or [2], wherein the alloy composition further includes 0.2 to 1.5 mass% of Zn.
[4] The copper alloy according to any one of [1] to [3], wherein the composition of the alloy further includes 0.01 to 0.2% by weight of Mg.
[5] The copper alloy according to any one of [1] to [4], wherein the alloy composition further includes 0.05 to 1.5 mass% of Sn.
[6] Ni is 2.0 to 4.5 mass%, Si is 0.3 to 1.0 mass%, Mg is 0.01 to 0.2 mass%, Sn is 0.05 to 1.5 mass% , A copper alloy containing 0.2 to 1.5 mass% of Zn, limiting S to less than 0.005 mass%, the balance being Cu and inevitable impurities, and X from the {311} plane on the plate surface When the line diffraction intensity is I {311}, the diffraction intensity from the {220} plane is I {220}, the diffraction intensity from the {200} plane is I {200}, and the crystal grain size is A (μm), A copper alloy for electronic equipment excellent in bending workability characterized by satisfying the formula (1).
I {311} × A / (I {311} + I {220} + I {200}) <1.5 (1)
[7] The alloy composition is further selected from the group consisting of 0.005 to 0.3% by mass of Zr, 0.05 to 2.0% by mass of Co, and 0.001 to 0.02% by mass of B. The copper alloy according to any one of [1] to [5], containing one or more elements in a total amount of 0.001 to 2.0 mass%.

[8] 2.0 to 4.5% by mass of Ni, 0.3 to 1.0% by mass of Si, 0.1 to 0.5% by mass of Cr, less than 0.005% by mass of S, and the balance Is a copper alloy composed of Cu and inevitable impurities, the X-ray diffraction intensity from the {311} plane on the plate surface is I {311}, the diffraction intensity from the {220} plane is I {220}, {200} plane A copper alloy characterized by satisfying the following formula (2) when the diffraction intensity from is I {200}.
I {311} / (I {311} + I {220} + I {200}) <0.15 (2)
[9] Ni is 2.0 to 4.5 mass%, Si is 0.3 to 1.0 mass%, Cr is 0.1 to 0.5 mass%, S is less than 0.005 mass%, and the balance is A copper alloy comprising Cu and inevitable impurities, wherein the X-ray diffraction intensity from the {311} plane on the plate surface is I {311}, the diffraction intensity from the {220} plane is from I {220}, {200} plane A copper alloy characterized by satisfying the following formula (3) when the diffraction intensity is I {200} and the crystal grain size is A (μm).
I {311} × A / (I {311} + I {220} + I {200}) <1.5 (3)
[10] The copper alloy according to [8] or [9], wherein the composition of the alloy further contains 0.2 to 1.5% by mass of Zn.
[11] The copper alloy according to any one of [8] to [10], wherein the alloy composition further includes 0.01 to 0.2% by mass of Mg.
[12] The copper alloy according to any one of [8] to [11], wherein the alloy composition further includes 0.05 to 1.5 mass% of Sn. And [13] the composition of the alloy is further Zr 0.005-0.3 mass%, Co 0.05-2.0 mass%, Ti 0.005-0.3 mass%, Ag 0 The copper according to any one of [8] to [12], comprising 0.005 to 0.3% by mass and B containing one or more selected from the group of 0.001 to 0.02% by mass alloy.

  The copper alloy of the present invention is excellent in strength, conductivity, bending workability (first embodiment described below), stress relaxation characteristics (second embodiment described below) and the like in addition to these. The copper alloy material obtained by processing this can cope with miniaturization and high performance of electric / electronic equipment parts. The copper alloy of the present invention is suitable for applications such as terminals, connectors, and switches, but is also suitable as a general conductive material for other switches and relays.

The present invention includes a first embodiment (means [1] to [7] for solving the above problems) and a second embodiment (means [8] to solving the above problems). [13]).
[First Embodiment]
In this embodiment, in a copper alloy having moderate strength and conductivity in which a compound of Ni and Si is precipitated in a Cu matrix, bending workability is improved by strictly controlling the degree of integration of crystal orientation and the crystal grain size. can do.

The relationship of the crystal orientation of the copper alloy (hereinafter simply referred to as the first copper alloy) in the first embodiment will be described below. In a copper alloy containing Ni and Si, the degree of integration of crystal orientation can be identified by limiting the X-ray diffraction intensity, and it has been found that bending workability and strength are improved by a function derived therefrom. That is, the X-ray diffraction intensity from the {311} plane on the plate surface is I {311}, the diffraction intensity from the {220} plane is I {220}, and the diffraction intensity from the {200} plane is I {200}, Furthermore, when the crystal grain size is A (μm), bending workability and strength are improved by satisfying the following formula (1).
I {311} × A / (I {311} + I {220} + I {200}) <1.5 (1)

  In the formula (1), the crystal orientation and crystal grain size are defined as less than 1.5, preferably less than 1.2. If it is 1.5 or more, it becomes impossible to achieve both bending workability and strength. If the copper alloy containing Ni and Si is recrystallized and the grain size increases, the accumulation ratio of {200} and {311} faces on the plate surface increases, and if the processing rate is increased in cold rolling, The accumulation rate of {220} planes increases as the value increases. The relationship between the degree of crystal orientation integration and the X-ray diffraction intensity is such that the higher the X-ray diffraction intensity, the higher the degree of crystal orientation integration. Here, the accumulation ratio of X-ray diffracting surfaces (accumulation degree of crystal orientation) refers to the ratio of crystal growth in each diffracting surface direction and can be evaluated by the ratio of X-ray diffraction intensity (I) of each diffracting surface. Is possible. In the present invention, evaluation is performed on the left side of the formula (1) (in this case, A = 1). The first copper alloy includes, for example, steps of “hot rolling”, “cold rolling”, “solution treatment”, “aging treatment”, and “finishing cold rolling” and “strain relief annealing” as necessary. Manufactured by. The degree of integration of crystal orientation and the crystal grain size vary depending on the combination of the pre-solution processing rate, the solution conditions, and the cold processing rate. In the present invention, in particular, the grain boundary embrittlement at the time of bending processing when the concentration of Ni and Si is increased is suppressed, and the degree of integration of these crystal orientations and the crystal grain size are defined for the purpose of improving bending workability. An appropriate range is obtained by equation (1).

The composition elements of the first copper alloy will be described below. When Ni and Si are added to Cu, a Ni—Si based compound (Ni ₂ Si phase) is precipitated in the Cu matrix and the strength and conductivity are improved. The reason for prescribing the Ni content to 2.0 to 4.5% by mass is that if it is less than 2.0% by mass, strength equal to or higher than that of low beryllium copper cannot be obtained. This is because not only does precipitation not contribute to strength improvement occur during hot working and the strength corresponding to the amount added cannot be obtained, but also hot workability and bending workability deteriorate, resulting in a problem of adverse effects. Preferably it is 2.2-4.2 mass%, More preferably, it is 3.0-4.0 mass%.

Since Si forms a Ni and Ni ₂ Si phase, the amount of Si added is determined when the amount of Ni is determined. S
If the amount of i is less than 0.3% by mass, the strength equal to or higher than that of low beryllium copper cannot be obtained in the same manner as when the amount of Ni is small. Occurs. Preferably it is 0.5-0.95 mass%, More preferably, it is 0.7-0.9 mass%.
The strength changes depending on the amounts of Ni and Si, and the stress relaxation characteristics change accordingly. Therefore, in order to obtain a stress relaxation characteristic equal to or higher than that of low beryllium copper, it is necessary to surely control the contents of Ni and Si within the range of this embodiment. Further, Mg, Sn and Zn described later are required. The content, crystal grain size and crystal grain shape are appropriately controlled.

  Mg, Sn, and Zn are important alloy elements constituting the present invention. These elements are related to each other and realize good characteristics in a balanced manner.

Mg greatly improves the stress relaxation properties, but adversely affects bending workability. For improvement of stress relaxation characteristics, the Mg content is preferably as large as 0.01% by mass or more, but if it exceeds 0.20% by mass, the bending workability does not satisfy the required characteristics. In the present invention, the amount of strengthening due to the precipitation of the Ni ₂ Si phase is markedly greater than that of conventional Cu—Ni—Si alloys, so that the bending workability is liable to deteriorate, so the Mg amount needs to be strictly controlled. Preferably it is 0.05-0.15 mass%.

  Sn correlates with Mg to further improve the stress relaxation characteristics. However, the effect is not as great as Mg. If Sn is less than 0.05% by mass, the effect is not sufficiently exhibited, and if it exceeds 1.5% by mass, the conductivity is greatly lowered. Preferably it is 0.1-0.7 mass%.

  Zn slightly improves the bending workability. By defining the amount of Zn to 0.2 to 1.5 mass%, even if Mg is added up to a maximum of 0.20 mass%, bending workability at a level where there is no practical problem can be obtained. In addition, Zn improves the adhesion and migration characteristics of Sn plating and solder plating. If the amount of Zn is less than 0.2% by mass, the effect cannot be sufficiently obtained, and if it exceeds 1.5% by mass, the conductivity is lowered. Preferably it is 0.3-1.0 mass%.

  Next, subcomponent elements of Co and Zr effective for strength improvement will be described. Co, like Ni, forms a compound with Si to improve the strength. The reason why the Co content is specified to be 0.05 to 2.0% by mass is that the effect is not sufficiently obtained when the content is less than 0.05% by mass, and the bending workability is lowered when the content exceeds 2.0% by mass. Because. Preferably it is 0.1-1.0 mass%.

  Zr precipitates finely in copper and contributes to the improvement of strength, and at the same time has the effect of lowering the degree of crystal orientation integration of formula (1). If it is less than 0.005% by mass, the effect cannot be sufficiently obtained, and if it exceeds 0.3% by mass, the bending workability deteriorates. From these viewpoints, the optimum content of Zr is set to 0.005 to 0.3% by mass. Preferably it is 0.05-0.2 mass%.

  The total content in the case of adding two or more of Co, Zr, and B is determined in the range of 0.005 to 2.0 mass% depending on the required characteristics. B forms a compound with Ni and lowers the degree of crystal orientation integration in formula (1). If the content of B is less than 0.001% by weight, the effect is not sufficiently obtained, and if it exceeds 0.02% by mass, hot workability is deteriorated. From these viewpoints, the optimum content of B is set to 0.001 to 0.02% by mass. Preferably it is 0.005-0.01 mass%.

  Although a trace amount of S is contained in the copper alloy, since the hot workability is deteriorated at 0.005 mass% or more, the content is specified to be less than 0.005 mass%. In particular, less than 0.002 mass% is desirable.

  In the present invention, Fe, P, Mn, Ti, V, Pb, Bi, Al, or the like may be added as long as the properties such as strength and conductivity are not deteriorated. For example, Mn has an effect of improving hot workability, and it is effective to add 0.01 to 0.5% by mass so as not to deteriorate the conductivity.

  The copper alloy containing Ni and Si recrystallizes, and as the grain size increases, the accumulation ratio of {200} and {311} faces on the plate surface increases, and rolling increases the accumulation ratio of {220} faces To do.

  The copper alloy is manufactured by, for example, processes of hot rolling, cold rolling, solution treatment, aging treatment, and further finish cold rolling and strain relief annealing as necessary. In this manufacturing process, each condition of hot rolling (temperature and time), subsequent cold rolling, volumeification treatment (temperature and time), and subsequent cold rolling process (working rate) is narrower than general conditions. By strictly controlling the range, the accumulation ratio and the crystal grain size can be controlled to satisfy the formula (1).

  In the production of a copper alloy, specifically, the hot rolling temperature is in the range of 900 to 1000 ° C, the cold rolling after hot rolling is performed at a processing rate of 90% or more, and the solution treatment temperature is 20 to 820 to 930 ° C. Within a second, the cold rolling is adjusted in the range of 30% or less to satisfy the formula (1).

  The final plastic working direction refers to the rolling direction when the last plastic working is rolling, and the drawing direction when drawing (drawing). The plastic processing is rolling processing or drawing processing, and does not include processing for the purpose of correction (straightening) such as a tension leveler.

[Second Embodiment]
In this embodiment, a Cu—Ni—Si based alloy was improved to satisfy recent needs by the following means, and in a copper alloy in which a compound of Ni and Si precipitated in a Cu matrix, the Cr content and the crystal orientation By controlling the degree of integration, bending workability and strength are improved.
Each component element of the copper alloy of the second embodiment (hereinafter simply referred to as the second copper alloy) will be described.
It is known that when Ni and Si are added to Cu, a Ni—Si based compound (Ni ₂ Si phase) is precipitated in the Cu matrix and the strength and conductivity are improved. In this invention, content of Ni is 2.0-4.5 mass%, Preferably it is 2.2-4.2 mass%, More preferably, it is 3.0-4.0 mass%.
The reason for defining the Ni content in this way is that if the amount is less than the lower limit, strength equal to or higher than beryllium copper cannot be obtained, and if the upper limit is exceeded, precipitation that does not contribute to strength improvement occurs during casting or hot working. This is because not only the strength suitable for the above can be obtained, but also the hot workability and bending workability are adversely affected.
Since Si forms a Ni and Ni ₂ Si phase, the optimum Si addition amount is determined when the Ni amount is determined. The amount of Si is 0.3 to 1.0 mass%, preferably 0.5 to 0.95 mass%, more preferably 0.7 to 0.9 mass%. If the amount of Si is small, strength equal to or higher than that of beryllium copper cannot be obtained in the same manner as when the amount of Ni is small, and if the amount of Si exceeds the above upper limit, the same problem as when the amount of Ni is large occurs.

By limiting the content and the X-ray diffraction intensity of Cr, the bending workability and strength of the alloy sheet are improved.
That is, by setting Cr to 0.1 to 0.5 mass% and satisfying the following formula (2) or formula (3), it is possible to achieve both bending workability and strength.
In addition, Cr is an Cr compound such as Cr—Si or Cr—Ni—Si in the alloy, and suppresses the coarsening of the crystal grain size during solution treatment, and has the effect of lowering the degree of crystal orientation accumulation in the prescribed formula. . However, if the amount of Cr is too small, the effect cannot be obtained sufficiently, and if it is too large, the bending workability deteriorates. From these viewpoints, the Cr content is 0.1 to 0.5 mass%, preferably 0.15 to 0.4 mass%.

Mg, Sn, and Zn are important alloy elements constituting the present invention. These elements are related to each other and realize good properties in a well-balanced manner. Mg improves stress relaxation properties but adversely affects bending workability. For improvement of stress relaxation characteristics, the higher the amount of Mg, the better. However, if it exceeds 0.20 mass%, the bending workability does not satisfy the required characteristics. In the present invention, the amount of strengthening due to the precipitation of the Ni ₂ Si phase is markedly greater than that of conventional Cu—Ni—Si alloys, so that the bending workability is liable to deteriorate, so the Mg amount needs to be strictly controlled. Preferably it is 0.05-0.15 mass%.
Sn correlates with Mg to further improve the stress relaxation characteristics. Sn is 0.0
If the amount is less than 5% by mass, the effect is not sufficiently exhibited. If the amount exceeds 1.5% by mass, the conductivity is significantly lowered. Preferably it is 0.1-0.7 mass%.

Zn improves bending workability. By defining the amount of Zn to 0.2 to 1.5 mass%, even if Mg is added up to a maximum of 0.20 mass%, bending workability at a level where there is no practical problem can be obtained. In addition, Zn improves the adhesion and migration characteristics of Sn plating and solder plating. If the amount of Zn is too small, the effect cannot be obtained sufficiently, and if it exceeds the specified amount, the conductivity is lowered. Preferably it is 0.3-1.0 mass%.

Zr, Co, Ti, Ag, and B all have the effect of lowering the degree of crystal orientation integration in the prescribed formula described later.
Zr has the effect of lowering the degree of crystal orientation integration in the following formula, and at the same time contributes to strength improvement. If it is less than 0.005% by mass, the effect cannot be sufficiently obtained, and if it exceeds 0.3% by mass, the bending workability deteriorates. From these viewpoints, the Zr content is set to 0.005 to 0.3 mass%. Preferably it is 0.05-0.2 mass%.
Co, like Ni, forms a compound with Si to improve the strength and has the effect of lowering the degree of crystal orientation integration in the specified formula. The reason why the Co content is specified to be 0.05 to 2.0% by mass is that the effect is not sufficiently obtained when the content is less than 0.05% by mass, and the bending workability is deteriorated when the content exceeds 2.0% by mass. Because. Preferably it is 0.1-1.0 mass%.
Co, like Cr, Zr, Ti, Ag, etc., has the effect of suppressing the coarsening of the crystal grain size and lowering the crystal orientation integration degree of the prescribed formula.

B has the effect of reducing the degree of crystal orientation integration in the formula. If the content of B is less than 0.001% by mass, sufficient effects cannot be obtained, and if it exceeds 0.02% by mass, hot workability deteriorates. From these viewpoints, the optimum content of B is set to 0.001 to 0.02% by mass. Preferably it is 0.005-0.1 mass%.
Ti has the effects of improving heat resistance and strength, suppressing the coarsening of the crystal grain size, and lowering the degree of crystal orientation integration in the prescribed formula. If the amount of Ti is less than 0.005% by mass, the effect cannot be sufficiently obtained. If the amount of Ti is 0.3% by mass or more, undissolved Ti remains, and the effect cannot be obtained. . From these viewpoints, the amount of Ti added is set to 0.005 to 0.3% by mass, preferably 0.05 to 0.2% by mass.

Ag improves heat resistance and strength, and at the same time, suppresses the coarsening of the crystal grain size and lowers the crystal orientation integration degree of the prescribed formula. If the amount of Ag is less than 0.005% by mass, the effect cannot be sufficiently obtained, and even if added in excess of 0.3% by mass, the properties are not adversely affected but the cost is increased. From these viewpoints, the Ag content is set to 0.005 to 0.3% by mass, preferably 0.05 to 0.2% by mass.
The total content when two or more of Co, Zr, Ti, Ag, and B are added simultaneously is determined in the range of 0.005 to 2.0 mass% depending on the required characteristics.

Although a small amount of S is contained in the copper alloy, if 0.005% by mass or more, hot workability is deteriorated, the content is specified to be less than 0.005% by mass. In particular, less than 0.002 mass% is desirable.
In the present invention, Fe, P, Mn, V, Pb, Bi, Al, or the like may be added as long as the properties such as strength and conductivity are not deteriorated. For example, Mn has an effect of improving hot workability, and it is effective to add 0.01 to 0.5% by mass so as not to deteriorate the conductivity.

Next, the crystal orientation of the second copper alloy will be described.
In a copper alloy containing Ni and Si, the crystals recrystallize, and as the grain size increases, the accumulation ratio of {200} and {311} faces on the plate surface increases, and when rolled, {220} faces accumulate The rate increases.
The second copper alloy is manufactured by, for example, hot rolling, cold processing, aging treatment, and further, if necessary, finishing cold rolling and strain relief annealing. In this manufacturing process, for example, hot rolling is performed. (Temperature and time), then cold rolling to be performed, solution treatment (temperature and time) subsequent cold rolling step (working rate) by controlling each condition strictly in a narrower range than the general conditions, This accumulation ratio and crystal grain size can be controlled.

It has been found that when the crystal orientation integration degree obtained from the X-ray diffraction intensity indicating the integration ratio is in a specific range, bending workability and strength are improved. Here, the accumulation ratio of X-ray diffracting surfaces (accumulation degree of crystal orientation) refers to the ratio of crystal growth in each diffracting surface direction and can be evaluated by the ratio of X-ray diffraction intensity (I) of each diffracting surface. Is possible. Specifically, the X-ray diffraction intensity from the {311} plane on the plate surface is I {311}, the diffraction intensity from the {220} plane is I {220}, and the diffraction intensity from the {200} plane is I {200}. When the following formula (2) is satisfied and the above-mentioned limited Cr amount is obtained, bending workability and strength are improved.
I {311} / (I {311} + I {220} + I {200}) <0.15 (2)
In the formula (2), the value of the degree of crystal orientation integration is 0.15 or less, preferably 0.12 or less. If this value is too large, it becomes impossible to achieve both bending workability and strength.
Similarly, the X-ray diffraction intensity from the {311} plane on the plate surface is I {311}, the diffraction intensity from the {220} plane is I {220}, and the diffraction intensity from the {200} plane is I {200}. Further, when the crystal grain size is A (μm), bending workability and tensile strength are improved by satisfying the following formula (3).
I {311} × A / (I {311} + I {220} + I {200}) <1.5 (3)
In the formula (3), the definition obtained from the crystal orientation integration degree and the crystal grain size is 1.5 or less, preferably 1.2 or less. If this value is too large as described above, it becomes impossible to achieve both bending workability and strength. For this reason, the smaller the crystal grain size, the better. Specifically, it is preferably less than 10 μm, more preferably 5 to 8 μm.

  In the production of the second copper alloy, specifically, the hot rolling temperature is in the range of 900 to 1000 ° C., the cold rolling after the hot rolling is performed at a working rate of 90% or more, and the solution treatment temperature is set to 820 to 930. Within 20 seconds at 0 ° C., cold rolling is adjusted in the range of 30% or less to satisfy the formula (2) or (3).

  The present invention will be described below in more detail based on examples, but the present invention is not limited thereto. In the examples, Examples 1 and 2 are examples of the first embodiment, and Examples 3 and 4 are examples of the second embodiment.

Example 1
The copper alloys (ingot Nos. A to V, WA to WH, X, and Z) having the prescribed compositions shown in Table 1 were melted in a high frequency melting furnace, and were 30 mm thick, 100 mm wide, and 150 mm long by the DC method. Cast into ingot. Next, these ingots were heated to 1000 ° C., held at this temperature for 1 hour, hot-rolled to a thickness of 12 mm, and quickly cooled.
Next, the hot-rolled plate was cut by 1.5 mm on both sides to remove the oxide film, and then processed into a thickness of 0.15 to 0.25 mm by cold rolling (a), and then the solution treatment temperature was 825. The temperature was changed in the temperature range of 925 ° C. and heat-treated for 15 seconds, and then immediately cooled at a cooling rate of 15 ° C./second or more. Next, an aging treatment was performed at 475 ° C. for 2 hours in an inert gas atmosphere, and then cold rolling (c) as the final plastic working was performed, so that the final plate thickness was adjusted to 0.15 mm. After the final plastic working, low temperature annealing was subsequently performed at 375 ° C. for 2 hours to produce a copper alloy sheet (sample No. 1, 5-41).

(Example 2)
A copper alloy sheet having a thickness of 0.15 mm was manufactured by processing a copper alloy (ingot No. J) having a prescribed composition shown in Table 1 under the following conditions. That is, the manufacturing conditions are the same as in Example 1 until the oxide film is removed after hot rolling, then processed to a thickness of 0.15 to 0.5 mm by cold rolling (ii), and then solutionized. It heat-processes for 15 second in the temperature range of process temperature 825 degreeC-925 degreeC, and it cools with the cooling rate of 15 degreeC / second or more immediately after that.
Thereafter, cold rolling (b) of 50% or less is performed, and then after the aging treatment in an inert gas atmosphere under the same conditions as in Example 1, the final plastic working (cold rolling (c), final plate thickness: 0.15 mm) was subjected to low-temperature annealing to produce copper alloy sheet materials (Sample Nos. 2 to 4).

  Each copper alloy sheet produced above was evaluated for (1) crystal grain size, (2) crystal orientation, (3) tensile strength, (4) conductivity, and (5) bending workability. The crystal grain size of (1) was measured based on JISH0501 (cutting method). (2) As for crystal orientation, X-rays were made incident on the surface of the copper alloy plate in the final product state (0.15 mm thickness), and the intensity from each diffraction plane was measured. Among them, the diffraction intensities of {200}, {220} and {311} planes having strong correlation with bending workability are compared, and the crystal orientation intensity ratio ([I {311} × A / (I {311} + I {220 } + I {200})]). The X-ray irradiation conditions are X-ray type CuKα1, tube voltage 40 kV, and tube current 20 mA. (3) Tensile strength was obtained according to JISZ2241 using a No. 5 test piece described in JISZ2201. (4) The electrical conductivity was determined according to JISH0505. The evaluation of the bending workability of (5) was based on the method described in JISH3110. The test piece width was 10 mm, and it was bent with a load of 1000 kgf. The specimen collection direction is GW (bending axis is perpendicular to the rolling direction) and BW (bending axis is parallel to the rolling direction), and the ratio R / of the minimum bending radius R and the specimen thickness t where no crack occurs. Evaluation was made at t.

As is clear from Table 2, sample no. 1, 5 to 19 (Example 1), Sample Nos. 2 to 4 (Example 2) have a bending workability (R / t) of less than 2, a tensile strength of 800 MPa or more, and a conductivity of 35% IACS or more. All are satisfied and have excellent properties. Sample No. Nos. 34 to 41 have excellent properties, although the tensile strength is slightly inferior, the bending workability (R / t) is less than 2, and the electrical conductivity satisfies 35% IACS or more.
On the other hand, sample Nos. 20 to 25 (comparative examples) are examples in which the value of the formula (1) is not specified and the bending workability is inferior. This is probably because the solution treatment temperature was too high.
No. Since No. 26 (Comparative Example) had a large amount of Ni and Si, cracks occurred during hot working and could not be produced normally.
No. 27 (Comparative Example of Claim 3) satisfies the value of the formula (1) and has excellent bending workability, but the conductivity is inferior because of the large amount of Zn.
No. 28 (Comparative Example of Claim 4) is inferior in bending workability because of a large amount of Mg.
No. 29 (Comparative Example of Claim 5) has a large amount of Sn, and therefore cracks occurred during cold rolling, and could not be produced.
Since No. 31 (Comparative Example of Claim 7) contains a large amount of B, cracking occurred during hot working, and it could not be manufactured normally.
Since No. 32 (Comparative Example of Claim 2) has a high S content, cracking occurred during hot working and production was stopped.
No. 33 is inferior in strength due to the small amount of Ni and Si, and does not reach that of beryllium copper.

Example 3
Copper alloys (ingot Nos. A to O, PA to PH, Q to S, Z, A-1) having the composition shown in Table 3 were melted in a high-frequency melting furnace, 30 mm thick and 100 mm wide by the DC method. And cast into an ingot having a length of 150 mm. Next, these ingots were heated to 1000 ° C., held at this temperature for 1 hour, hot-rolled to a thickness of 12 mm, and quickly cooled.
Next, the hot-rolled plate was cut by 1.5 mm on both sides to remove the oxide film, and then processed to a thickness of 0.15 to 0.25 mm by cold rolling (ii), and then the solution treatment temperature was 825 ° C. The temperature was changed in a temperature range of ˜925 ° C. and heat-treated for 15 seconds, and then immediately cooled at a cooling rate of 15 ° C./second or more. Next, an aging treatment was performed for 2 hours at 475 ° C. in an inert gas atmosphere, and then cold rolling (c) as the final plastic working was performed, so that the final plate thickness was adjusted to 0.15 mm. After the final plastic working, low temperature annealing was subsequently performed at 375 ° C. for 2 hours to produce copper alloy sheet materials (Sample Nos. 0-2, 1-1, 5-30).

Example 4
A copper alloy (ingot No. B) having the composition shown in Table 3 was processed under the following conditions to produce a copper alloy sheet having a thickness of 0.15 mm. That is, the manufacturing conditions are the same as in Example 3 until the oxide film is removed after hot rolling, then processed to a thickness of 0.15-0.5 mm by cold rolling (ii), and then solution treatment. Heat treatment is performed at a temperature range of 825 ° C. to 925 ° C. for 15 seconds, and then immediately cooled at a cooling rate of 15 ° C./second or more. Thereafter, cold rolling (b) of 50% or less is performed, and then aging treatment is performed in an inert gas atmosphere under the same conditions as in Example 3, and the final plastic working (cold rolling (c), final plate thickness is performed. : 0.15 mm), low-temperature annealing was performed to produce copper alloy sheet materials (Sample Nos. 3 and 4).

For each copper alloy sheet produced in Examples 3 and 4, (1) crystal grain size, (2) crystal orientation, (3) bending workability, (4) tensile strength, (5) conductivity, (6) Stress relaxation characteristics were measured and evaluated.
(1) The crystal grain size was measured based on JIS H 0501 (cutting method).
(2) For crystal orientation, X-rays were made incident on the surface of the copper alloy plate in the final product state (0.15 mm thickness), and the intensity from each diffraction plane was measured. Among them, the diffraction intensity of {200}, {220} and {311} planes is compared, and the degree of crystal orientation accumulation ([I {311} / (I {311} + I {220} + I {200})]), And I {311} × A / (I {311} + I {220} + I {200}). The X-ray irradiation conditions are X-ray type: CuKα1, tube voltage: 40 kV, tube current: 20 mA.
(3) Evaluation of bending workability was based on the method described in JIS H 3110. The test piece was 10 mm wide and bent under a load of 1000 kgf. The specimen collection direction is GW (bending axis is perpendicular to the rolling direction) and BW (bending axis is parallel to the rolling direction), and the ratio R / Evaluation was made at t.
(4) Tensile strength was determined based on JIS Z 2241 using No. 5 test piece described in JIS Z 2201.
(5) The conductivity was determined according to JIS H 0505.
(6) The stress relaxation characteristics are based on the Japan Electronic Materials Manufacturers Standard (EMAS-3003) cantilever block type, and the load stress is set so that the maximum surface stress is 80% YS (0.2% proof stress). Then, the relaxation rate (S.R.R.) was obtained by holding in a thermostatic bath at 150 ° C. for 1000 hours.
The measured values obtained are shown in Table 4.

As apparent from Table 4, the sample No. 0-2, 1-1, 5-11 (Example 3) and Sample Nos. 3 and 4 (Example 4) have a bending workability (R / t) of less than 2, a tensile strength of 810 MPa or more, and conductivity. Satisfies 35% IACS or more and a relaxation rate of 10% or less. Sample No. 23 to 30 have some inferior tensile strength and relaxation rate, bending workability (R / t) of less than 2, electrical conductivity of 35% IACS or more, and excellent characteristics is doing.
In contrast, sample no. Nos. 12 and 13 (comparative examples) are examples in which the value of the formula (2) or (3) is out of the range and the bending workability is inferior. This is probably because the solution treatment temperature was too high.
No. 14 (Comparative Example) was inferior in bending workability due to a large amount of Cr.
No. No. 15 (Comparative Example) could not be produced because of the large amount of Ni and Si, causing cracks during hot working.
No. No. 16 (Comparative Example of Claim 10) was inferior in electrical conductivity because of a large amount of Zn.
No. 17 (Comparative Example of Claim 11) is excellent in stress relaxation properties due to a large amount of Mg, but inferior in bending workability.
No. No. 18 (Comparative Example of Claim 12) could not be produced because of a large amount of Sn and cold work cracking.
No. 19 (Comparative Example of Claim 13) was inferior in bending workability due to the large amount of Zr and Co.
No. Since 20 (Comparative Example) contained a large amount of S, cracks occurred during hot working and could not be produced.
No. Since No. 21 (Comparative Example of Claim 13) had a large amount of B and Ti, cracks occurred during hot working and could not be produced.
No. 22 (Comparative Example) was inferior in strength and stress relaxation rate due to the small amount of Ni and Si.

Claims (13)

X-ray from {311} plane on the plate surface, comprising a copper alloy containing 2.0 to 4.5% by mass of Ni and 0.3 to 1.0% by mass of Si with the balance being Cu and inevitable impurities When the diffraction intensity is I {311}, the diffraction intensity from the {220} plane is I {220}, the diffraction intensity from the {200} plane is I {200}, and the crystal grain size is A (μm), A copper alloy for electronic equipment excellent in bending workability characterized by satisfying (1).
I {311} × A / (I {311} + I {220} + I {200}) <1.5 (1) A copper alloy comprising 2.0 to 4.5% by mass of Ni, 0.3 to 1.0% by mass of Si, S exceeding 0 and less than 0.005% by mass, with the balance being Cu and inevitable impurities. X-ray diffraction intensity from the {311} plane on the plate surface is I {311}, diffraction intensity from the {220} plane is I {220}, diffraction intensity from the {200} plane is I {200}, crystal grains A copper alloy for electronic equipment with excellent bending workability, characterized by satisfying the following formula (1) when the diameter is A (μm).
I {311} × A / (I {311} + I {220} + I {200}) <1.5 (1)   The copper alloy according to claim 1 or 2, wherein the alloy composition further contains 0.2 to 1.5 mass% of Zn.   The copper alloy according to any one of claims 1 to 3, wherein the alloy composition further includes 0.01 to 0.2 mass% of Mg.   The copper alloy according to any one of claims 1 to 4, wherein the alloy composition further includes 0.05 to 1.5 mass% of Sn. Ni is 2.0 to 4.5 mass%, Si is 0.3 to 1.0 mass%, Mg is 0.01 to 0.2 mass%, Sn is 0.05 to 1.5 mass%, Zn is X-ray diffraction intensity from the {311} plane on the plate surface containing 0.2 to 1.5% by mass, S limited to less than 0.005% by mass, the balance being Cu and inevitable impurities Where I {311}, the diffraction intensity from the {220} plane is I {220}, the diffraction intensity from the {200} plane is I {200}, and the crystal grain size is A (μm). ) Copper alloy for electronic equipment with excellent bending workability.
I {311} × A / (I {311} + I {220} + I {200}) <1.5 (1) The alloy composition is further selected from the group consisting of 0.005 to 0.3 mass% Zr, 0.05 to 2.0 mass% Co, and 0.001 to 0.02 mass% B or The copper alloy according to any one of claims 1 to 5, comprising two or more elements in a total amount of 0.001 to 2.0 mass%. It contains 2.0 to 4.5% by mass of Ni, 0.3 to 1.0% by mass of Si, 0.1 to 0.5% by mass of Cr, less than 0.005% by mass of S, the balance being Cu and A copper alloy composed of unavoidable impurities, the X-ray diffraction intensity from the {311} plane on the plate surface is I {311}, the diffraction intensity from the {220} plane is I {220}, and the diffraction from the {200} plane A copper alloy characterized by satisfying the following formula (2) when the strength is I {200}.
I {311} / (I {311} + I {220} + I {200}) <0.15 (2) It contains 2.0 to 4.5% by mass of Ni, 0.3 to 1.0% by mass of Si, 0.1 to 0.5% by mass of Cr, less than 0.005% by mass of S, the balance being Cu and A copper alloy composed of unavoidable impurities, the X-ray diffraction intensity from the {311} plane on the plate surface is I {311}, the diffraction intensity from the {220} plane is I {220}, and the diffraction from the {200} plane A copper alloy characterized by satisfying the following formula (3) when the strength is I {200} and the crystal grain size is A (μm).
I {311} × A / (I {311} + I {220} + I {200}) <1.5 (3)   The copper alloy according to claim 8 or 9, wherein the alloy composition further contains 0.2 to 1.5 mass% of Zn.   The copper alloy according to any one of claims 8 to 10, wherein the alloy composition further contains 0.01 to 0.2 mass% of Mg.   The copper alloy according to any one of claims 8 to 11, wherein the composition of the alloy further includes 0.05 to 1.5 mass% of Sn. The composition of the alloy is further 0.005 to 0.3% by mass of Zr, 0.05 to 2.0% by mass of Co, 0.005 to 0.3% by mass of Ti, and 0.005 to 0 of Ag. The copper alloy according to any one of claims 8 to 12, comprising one or more selected from a group of .3% by mass and B from 0.001 to 0.02% by mass.