JP5261619B2 - Copper alloy sheet and manufacturing method thereof - Google Patents

Abstract

Provided is a copper alloy sheet material which has a composition containing 1.0-5.0 mass% Ni and 0.1-2.0 mass% Si, with the remainder comprising copper and incidental impurities. The copper alloy sheet material, in analysis for crystal orientation by electron backscatter diffractometry, contains crystal grains having an orientation that is offset at 15º or less from the cube orientation {001}<100>, in an areal proportion of 5-50%, wherein the number of such crystal grains having an orientation that is offset at 15º or less from the cube orientation {001}<100> which have been dispersed per area 60 µm square is 40-100. Also provided is a process for producing the copper alloy sheet material. This copper alloy sheet material has excellent bendability and excellent strength, has reduced anisotropy in various properties between the direction parallel to the rolling direction and the direction perpendicular to the rolling direction, and is suitable for use in applications such as lead frames, connectors, terminal materials, etc. for electrical/electronic appliances and connectors, terminal materials, relays, switches, etc. for mounting on motor vehicles, etc.

Description

  The present invention relates to a copper alloy plate material applied to a lead frame, a connector, a terminal material, a relay, a switch, a socket, and the like for an electric / electronic device and a manufacturing method thereof.

  Characteristic items required for copper alloy materials used for electric / electronic equipment applications include conductivity, yield strength (yield stress), tensile strength, bending workability, stress relaxation resistance, and the like. In recent years, with the miniaturization, lightening, high functionality, high density mounting, and high temperature of the usage environment of electric / electronic devices, the required level of these characteristics is increasing.

  Conventionally, as materials for electric and electronic devices, copper-based materials such as phosphor bronze, red brass, brass and the like are widely used in addition to iron-based materials. These alloys have improved strength by a combination of solid solution strengthening of Sn and Zn and work hardening by cold working such as rolling and wire drawing. In this method, the electrical conductivity is insufficient, and a high strength is obtained by applying cold working at a high rolling rate, so that bending workability and stress relaxation resistance are insufficient.

  As an alternative strengthening method, there is a precipitation strengthening method in which a fine second phase is precipitated in the material. This strengthening method has the advantage of improving the conductivity at the same time in addition to increasing the strength, and is therefore performed in many alloy systems. However, with the recent miniaturization of parts used in electronic equipment and automobiles, copper alloys have been subjected to bending with a smaller radius on higher-strength materials. There is a strong demand for alloy sheets. Furthermore, it is not preferable that there is a difference in properties between the rolling parallel direction and the rolling vertical direction even in a plate material having high strength, high spring property and good bending workability, and it is important to show good properties in any direction. is there. In particular, when used as an ultra-compact terminal, it is important that fine processing is applied to the pin type with a narrow width, and here also shows good characteristics in any direction. In the conventional Cu-Ni-Si-based copper alloy, in order to obtain high strength, the rolling rate was increased and a large work hardening was obtained. However, this method deteriorates the bending workability as described above, and high It was difficult to achieve both strength and good bending workability.

  Several proposals have been made to solve this demand for improvement in bending workability by controlling the crystal orientation. For example, the following proposals have been made for Cu—Ni—Si based copper alloys. Patent Document 1 discloses that in a Cu—Ni—Si based copper alloy, the crystal grain size and the crystal orientation such that the X-ray diffraction intensity I from the {311}, {220}, and {200} planes satisfies a certain condition are satisfied. In some cases, it is disclosed that bending workability is excellent. Patent Document 2 discloses that in a Cu—Ni—Si-based copper alloy, bending workability is excellent when the crystal orientation satisfies the condition that the X-ray diffraction intensity from the {200} plane and the {220} plane is satisfied. It is disclosed. Patent Document 3 discloses that in a Cu—Ni—Si-based copper alloy, bending workability is excellent by controlling the ratio of the cube orientation {001} <100> to 50% or less. In Patent Document 4, in a Cu—Ni—Si based copper alloy, a crystal structure in a distorted state by strong cold working is recrystallized to change to a crystal structure having a small anisotropy and to improve elongation. It is disclosed that bending workability is improved. In Patent Document 5, in a Cu—Ni—Si based copper alloy, the strength of anisotropy is small by controlling the crystal grain size and the ratio of cube orientation {001} <100> to 20 to 60%. Is disclosed to be superior. In Patent Document 6, in a Cu—Ni—Si based copper alloy, the mechanical strength, electrical conductivity and bending workability are controlled by controlling the crystal grain size and the ratio of the cube orientation {001} <100> to 5 to 50%. It is disclosed to improve fatigue characteristics without impairing the resistance.

  In the inventions described in Patent Document 1 and Patent Document 2, the analysis of crystal orientation by X-ray diffraction from a specific surface relates to a very small number of specific surfaces in the distribution of crystal orientation having a certain spread. It is. In the invention described in Patent Document 3, the crystal orientation is controlled by reducing the rolling rate after solution heat treatment. Further, the area and dispersibility of the cube-oriented crystal grains are not described, and the bending workability and the strength anisotropy are not disclosed. In the invention described in Patent Document 4, the crystal structure in a distorted state by strong cold rolling is recrystallized to realize a crystal structure with small anisotropy, and good bending workability is achieved by improving the elongation. Although realized, the characteristics are not improved by controlling the crystal orientation. In the invention described in Patent Document 5, the cube orientation is accumulated by adjusting processes such as the rolling reduction in cold rolling before the solution treatment, the heating rate in the solution treatment, and the strength and bending work. The anisotropy in sex is reduced. However, in Patent Document 5, since the temperature rising rate in the solution treatment is slow, the temperature rising time is long. As a result, the cube oriented crystal grains are coarse and the uniform dispersibility of the cube oriented crystal grains is inferior. The anisotropy of strength is also great. Moreover, in the invention described in Patent Document 6, cold rolling before the solution treatment is performed at a high reduction ratio of 85 to 99.8%, and the heating temperature and the holding time in the subsequent solution treatment are adjusted. As a result, the cube orientation is accumulated and the fatigue characteristics are improved. However, in Patent Document 6, the cube-oriented crystal grains obtained as a result of the solution treatment are coarse, the uniform dispersibility of the cube-oriented crystal grains is inferior, and the strength anisotropy is large.

  In addition, as one of the characteristic items required for copper alloy materials used for electric / electronic equipment applications, a low Young's modulus (longitudinal elastic modulus) is required. In recent years, with the progress of miniaturization of electronic parts such as connectors, the dimensional accuracy of terminals and the tolerance of press working have become severe. By reducing the Young's modulus of the material, the influence of dimensional variation on the contact contact pressure can be reduced, so that the design becomes easy. The Young's modulus is measured from a method of calculating from the slope of the elastic region of the stress-strain diagram obtained by a tensile test, and from the slope of the elastic region of the stress-strain diagram when the beam (cantilever) is bent. There are two ways to do this.

JP 2006-009137 A JP 2008-013836 A JP 2006-283059 A JP 2005-350695 A JP 2011-162848 A JP 2011-012321 A

  In view of the problems of the prior art as described above, the present invention is excellent in bending workability, has excellent strength, and has little anisotropy between the rolling parallel direction and the rolling vertical direction of each characteristic. It is an object of the present invention to provide a copper alloy plate material suitable for equipment such as lead frames, connectors, terminal materials for automobiles, connectors and terminal materials for automobiles, relays, switches, and the like. Another object is to provide a production method suitable for obtaining the copper alloy sheet.

  The present inventors have conducted intensive research on copper alloys suitable for electric / electronic component applications, and in order to greatly improve bending workability, strength, and conductivity in Cu—Ni—Si based copper alloy sheet materials, It was found that there was a correlation between the orientation accumulation ratio and bending workability. Moreover, in the copper alloy sheet having the crystal orientation and characteristics, an alloy composition that works to further improve the strength is found, and in addition, the strength is improved without impairing the conductivity and bending workability in this alloy system. The copper alloy sheet material which added the element which has a function was discovered. In addition, in order to realize the crystal orientation as described above, a manufacturing method having a specific process has been found based on the fact that there is a correlation between the accumulation ratio of the cube orientation and the bending workability. The present invention has been made as a result of studies based on these findings.

That is, according to the present invention, the following means are provided.
(1) Ni is contained in an amount of 1.0% by mass or more and 5.0% by mass or less, Si is contained in an amount of 0.1% by mass or more and 2.0% by mass or less, and the balance is composed of copper and inevitable impurities.
In the crystal orientation analysis by the electron backscatter diffraction method, the area ratio of crystal grains having an orientation whose deviation from the cube orientation {001} <100> is within 15 ° is 5% or more and 50% or less, and the cube orientation {001 } A copper alloy plate material, wherein crystal grains having an orientation with a deviation from <100> within 15 ° are dispersed in a range of 40 to 100 in a 60 μm square.
(2) Ni is 1.0 mass% or more and 5.0 mass% or less, Si is 0.1 mass% or more and 2.0 mass% or less, Sn, Zn, Ag, Mn, B, P, Mg, Cr, Zr , Containing at least one selected from the group consisting of Fe and Hf in a total of 0.005 mass% to 1.0 mass%, with the balance being composed of copper and inevitable impurities,
In the crystal orientation analysis by the electron backscatter diffraction method, the area ratio of crystal grains having an orientation whose deviation from the cube orientation {001} <100> is within 15 ° is 5% or more and 50% or less, and the cube orientation {001 } A copper alloy plate material, wherein crystal grains having an orientation with a deviation from <100> within 15 ° are dispersed in a range of 40 to 100 in a 60 μm square.
(3) cube orientation {001} the average grain area of crystal grains deviation has a direction is within 15 ° from the <100> is 1.8 .mu.m ² or more 45.0Myuemu ² or less (1) or (2) The copper alloy sheet material according to item.
(4) The copper alloy sheet according to any one of (1) to (3), wherein an average crystal grain area of crystal grains of the base material is 50 μm ² or less.
(5) The difference between the deflection coefficient in the rolling parallel direction and the deflection coefficient in the rolling vertical direction is 10 GPa or less in absolute value, and the difference between the proof stress in the rolling parallel direction and the proof stress in the rolling vertical direction is 10 MPa or less in absolute value. The copper alloy sheet material of any one of (4).
(6) An intermediate solution in which the ingot obtained by casting a copper alloy material is subjected to homogenization heat treatment and hot rolling, further formed into a thin plate by cold rolling, and then re-dissolved solute atoms in the thin plate A method for producing a copper alloy sheet material that is subjected to hydrothermal treatment,
The copper alloy material has an alloy composition of the copper alloy sheet according to the item (1) or (2),
The homogenization heat treatment is performed at 800 ° C. or more and 1020 ° C. or less for 3 minutes to 10 hours,
After performing the cold rolling at a rolling rate of 80% or more and 99.8% or less, intermediate annealing is performed for 5 seconds to 20 hours at a temperature of 400 ° C. or more and 700 ° C. or less which is less than the recrystallization temperature,
Further, after heating to 100 ° C. or more and 400 ° C. or less and performing an intermediate warm rolling at a rolling rate of 5% or more and 50% or less at that temperature,
The intermediate solution heat treatment is performed at 600 to 1000 ° C. for 5 seconds to 1 hour,
A method for producing a copper alloy sheet comprising the steps of performing an aging precipitation heat treatment at 400 ° C. to 700 ° C. for 5 minutes to 10 hours in this order.

According to the copper alloy sheet material of the present invention, it is possible to provide a copper alloy sheet material that is excellent in bending workability, exhibits excellent strength, and has little anisotropy in the rolling parallel direction and the rolling vertical direction. Accordingly, it is possible to provide a copper alloy plate material having properties particularly suitable for connectors, terminal materials, relays, switches, and the like for automobiles and the like, such as lead frames, connectors, and terminal materials for electric and electronic devices.
Moreover, according to the manufacturing method of this invention, the said copper alloy board | plate material can be manufactured suitably.

  The above and other features and advantages of the present invention will become more apparent from the following description, with reference where appropriate to the accompanying drawings.

FIG. 1 is a diagram for explaining equal dispersibility in a case where four adjacent blocks are one group and there are at least four groups.

  A preferred embodiment of the copper alloy sheet material of the present invention will be described. The “plate material” in the present invention includes “strip material”.

The copper alloy sheet of the present invention has a composition containing Ni in an amount of 1.0% by mass or more and 5.0% by mass or less, Si in an amount of 0.1% by mass or more and 2.0% by mass or less, with the balance being copper and inevitable impurities. Have. Preferably, Ni is 3.0% by mass or more and 5.0% by mass or less, and Si is 0.5% by mass or more and 2.0% by mass or less. Particularly preferably, Ni is 4.0% by mass or more and Si is 1.0% by mass or more.
In the crystal orientation analysis by the electron backscattering diffraction method, the area ratio of the cube orientation {001} <100> (hereinafter sometimes referred to as the cube orientation area ratio) is 5% or more and 50% or less, preferably It is 10% or more and 45% or less, more preferably 15% or more and 40% or less, and particularly preferably 20% or more and 35% or less.
Or a copper alloy board | plate material contains 1.0 mass% or more and 5.0 mass% or less of Ni, 0.1 mass% or more and 2.0 mass% or less of Si, Sn, Zn, Ag, Mn, B, P, A total of at least one selected from the group consisting of Mg, Cr, Zr, Fe and Hf may be 0.005 mass% or more and 1.0 mass% or less. The total of at least one selected from the group consisting of Sn, Zn, Ag, Mn, B, P, Mg, Cr, Zr, Fe and Hf is preferably 0.01% by mass or more and 0.9% by mass or less, More preferably, it is 0.03 mass% or more and 0.8 mass% or less, Most preferably, it is 0.05 mass% or more and 0.5 mass% or less. Also in this case, the preferable content of Ni and Si, the particularly preferable content, and the preferable range and particularly preferable range of the cube orientation area ratio are the same as those described above.

In each copper alloy sheet, the average grain area of crystal grains having an orientation deviation is within 15 ° from the cube orientation {001} <100> is preferably 1.8 .mu.m ² or more 45.0Myuemu ² below There, more preferably 3.8 .mu.m ² or more 36.0Myuemu ² or less. More preferably 6.0 .mu.m ² or more 28.8Myuemu ² or less, particularly preferably 10.0 [mu] m ² or more 25.0 ² below.
In this document, the average grain area of the crystal grains having an orientation whose deviation from the cube orientation {001} <100> is within 15 ° is omitted, and the cube orientation area ratio or the cube orientation {001} <100> area It may be rate. Further, a crystal grain having an orientation whose deviation from the cube orientation {001} <100> is within 15 ° may be omitted, and a cube orientation crystal grain or a crystal grain having a cube orientation {001} <100> may be referred to. .

The average crystal grain area of the base material containing the crystal grains of the cube orientation is preferably 40 μm ² or less, more preferably 5 to 30 μm ² . The average value of the crystal grain area was calculated from the EBSD measurement result in the range of 300 × 300 μm on the plate material plane, and was defined as the average crystal grain area.
Furthermore, in crystal orientation analysis by electron backscatter diffraction, 40 to 100 crystal grains having a cube orientation {001} <100> are distributed within 60 μm square and have equal dispersibility. The crystal grains of the cube orientation {001} <100> have an equal dispersibility in a 60 μm square, preferably 45 to 95 particles, particularly preferably 50 to 90 particles and the like. It has dispersibility.

Furthermore, as a bending workability in the rolling parallel direction and the rolling vertical direction, it is preferable that cracks do not occur on the bending surface in 180 ° U contact bending in a narrow bending process of 1 mm width or less.
Furthermore, the difference between the deflection coefficient in the rolling parallel direction (//) and the deflection coefficient in the rolling vertical direction (⊥) is an absolute value, preferably 10 GPa or less, more preferably 8 GPa or less, and particularly preferably 5 GPa. It is as follows. The difference between the proof stress in the rolling parallel direction and the proof stress in the vertical direction of rolling is an absolute value, preferably 10 MPa or less, more preferably 8 MPa or less, and particularly preferably 5 MPa or less. These differences are preferably smaller, meaning that the isotropic property is higher. Ideally, these differences are all 0 (zero), that is, it is most preferable that the values in the rolling parallel direction and the rolling vertical direction are the same.

  The copper alloy sheet material of the present invention has an area ratio of the cube orientation {001} <100> and its average crystal grain area, and more preferably the average crystal grain area of the base material is within the above range. The 180 ° U contact bending does not generate a crack at the apex of the bent portion, and good bending characteristics are obtained, and the deflection anisotropy and the proof stress anisotropy are reduced. On the other hand, if the area ratio is too small or the average crystal grain area is too large, or if the average crystal grain area of the base material is too large, cracks are likely to occur at the apex of the bent portion, and good bending characteristics are obtained. Cannot be obtained, and the deflection anisotropy and the proof stress anisotropy are increased.

The copper alloy sheet of the present invention contains 1.0 mass% to 5.0 mass% Ni and 0.1 mass% to 2.0 mass% Si. As a result, a Ni—Si based compound (Ni ₂ Si phase) is precipitated in the Cu matrix and the strength and conductivity are improved. On the other hand, if the Ni content is too low, strength cannot be obtained, and if it is too high, precipitation that does not contribute to strength improvement during casting or hot working occurs, and the strength corresponding to the added amount cannot be obtained. And bending workability is lowered. Since Si forms a Ni and Ni ₂ Si phase, the amount of Si added is determined when the amount of Ni is determined. However, if the amount of Si is too small, the strength cannot be obtained, and if the amount of Si is too large, the amount of Ni is large. Similar problems arise. Therefore, the addition amount of Ni and Si is preferably within the above range.

Next, the area ratio of the cube orientation {001} <100> will be described.
In order to improve the bending workability of the copper alloy sheet, the present inventors investigated the cause of the occurrence of cracks in the bent portion. As a result, it was confirmed that the plastic deformation was locally developed to form a shear deformation band, and the generation and connection of microvoids occurred due to local work hardening, reaching the forming limit. As a countermeasure, the present inventors have found that it is effective to increase the proportion of crystal orientation in which work hardening hardly occurs in bending deformation. That is, as described above, it was found that excellent bending workability is exhibited when the area ratio of the cube orientation {001} <100> is 5% or more and 50% or less.
When the area ratio of the cube orientation {001} <100> is within the above range, the above-described effects are sufficiently exhibited. Moreover, it exists in the said range, since intensity | strength does not fall remarkably even if it does not perform the cold rolling process after a recrystallization process by a low rolling rate, it is preferable. That is, the cold rolling process after the recrystallization process can be performed at a high rolling rate without significantly reducing the strength. On the other hand, when the area ratio of the cube orientation {001} <100> is too low, the bending workability deteriorates. Conversely, when the area ratio of the cube orientation {001} <100> is too high, the strength decreases. Therefore, from the above viewpoint, the area ratio of the cube orientation {001} <100> is 5% or more and 50% or less, but this preferable range is 10% or more and 45% or less, and a more preferable range is 15% or more and 40%. The particularly preferable range is 20% or more and 35% or less.

  Next, another orientation of the cube orientation in the above range will be described. In the copper alloy sheet of the present invention, the S orientation {3 2 1} <4 3 6>, the copper orientation {1 2 1} <1 -1 1>, the D orientation {4 11 4} <11 -8 11>, A brass orientation {1 1 0} <1 −1 2>, a Goss orientation {1 1 0} <0 0 1>, an RDW orientation {1 0 2} <0 1 0>, and the like are generated. These azimuth | direction components are accept | permitted if the cube azimuth | direction area ratio is in said range with respect to the area of all the directions observed.

As described above, the electron backscatter diffraction (hereinafter referred to as EBSD) method is used for the analysis of the crystal orientation in the present invention. The EBSD method is an abbreviation of Electron BackScatter Diffraction, and uses a backscattered electron diffraction pattern (EBSP) generated when an electron beam is irradiated to one point on the sample surface in a scanning electron microscope (SEM). This is a crystal orientation analysis technique for analyzing the crystal orientation and crystal structure in the local region.
The crystal orientation was analyzed by scanning the sample area of 1 mm square containing 200 or more crystal grains in 0.1 μm steps. From the size of the crystal grains of the sample, the measurement area was set to 300 μm × 300 μm. The area ratio of each orientation is the ratio of the area of crystal grains having orientations within 15 ° of the cube orientation {001} <100> from the ideal orientation to the total measured area. The information obtained in the azimuth analysis by the EBSD method includes azimuth information up to a depth of several tens of nanometers at which the electron beam penetrates into the sample, but is sufficiently small with respect to the measured width. Then, it described as an area ratio. Further, since the azimuth distribution changes in the plate thickness direction, it is preferable that the azimuth analysis by the EBSD method takes an average for any number of points in the plate thickness direction. In the present application, unless otherwise specified, the area ratio of a crystal plane having a certain crystal orientation is referred to as measured in this way.

Next, the equal dispersibility of the crystal grains having the cube orientation {001} <100> will be described.
In order to investigate the dispersibility of cube-oriented crystal grains, a 300 μm × 300 μm range was scanned in 0.1 μm steps by crystal orientation analysis by the EBSD method, of which 60 μm square was one block, and a total of 25 blocks were analyzed It was. The area ratio, number of cube-oriented crystal grains per block, average crystal grain area, and average crystal grain area of the base material containing cube-oriented grains were confirmed, and the dispersibility was investigated. As described above, the cube orientation area ratio is 5% or more and 50% or less, the number of cube orientation crystal grains is 40 or more and 100 or less, and the average grain area per cube orientation crystal grain is 1. 8 [mu] m ² or more 45.0Myuemu ² or less, more cube where oriented grains is equal to or less than the average crystal grain area 50 [mu] m ² of base material that contains, the cube oriented crystal grains per 1 field of view in the present invention (300μm × 300μm) equal Quantified as dispersibility. The equal dispersibility is obtained by multiplying the area of one block (60 μm × 60 μm = 3600 μm ² ) by the cube orientation area ratio of the block to obtain the total area of cube orientation crystal grains per block, and the value of the total area is 1 block. The average area per cube oriented crystal grain in one block is calculated by dividing by the number of cube oriented crystal grains. The obtained value is the average crystal grain area. Here, “equal dispersibility” defines the average grain area and number of cube-oriented grains per block, and even if the distribution of cube-oriented grains is biased, 25 blocks are accumulated. The same dispersibility can be confirmed when viewed as a whole of 300 × 300 μm. For example, when the bending portion of the narrow pin (0.25 mm = 250 μm) of the microminiature connector is 250 × 250 μm, the cube orientation group is included in at least four blocks, and it can be said that there is equal dispersibility. . As shown in FIG. 1, even if the cube orientation is accumulated at the corners of four adjacent blocks, the dispersibility is equal and the anisotropy in the rolling parallel and vertical directions is small. Here, the equal dispersibility (in the case of at least four groups including four adjacent blocks as one group) can be further defined by setting the area of one block smaller. For example, the area of one block is 30 μm square, and 10 to 25 cube orientation {001} <100> crystal grains exist in one block, and the crystal grain area ratio of cube orientation {001} <100> Is 5 to 50%, and the average crystal grain area of the crystal grains of the cube orientation {001} <100> is preferably 1.8 to 45.0 μm ² . In this case, the average crystal grain area of the crystal grains of the base material is preferably 40 μm ² or less.

When the average crystal grain area of the cube orientation crystal grains is too small, the solution heat treatment is insufficient, an unrecrystallized structure remains, and the strength and bending workability may be reduced. On the other hand, when the average crystal area of the cube-oriented crystal grains is too large, there is a high possibility that cracks will occur at the portion of the crystal grains having an orientation other than the cube-oriented crystal grains during bending. Also, anisotropy may occur depending on the bending direction. Therefore, the average crystal area of the cube-oriented crystal grains is preferably set in the above range.
In addition, since the cube-oriented crystal grains are distributed in the range of 40 to 100 in a square of 60 μm and have equal dispersibility, good bending characteristics can be obtained without causing cracks at the apex of the bent portion. Anisotropy and yield anisotropy are reduced. On the other hand, if the number of cube-oriented crystal grains distributed in a 60 μm square is too small, cracks are generated at the apex of the bent portion, and good bending characteristics cannot be obtained, and the flexural anisotropy and yield anisotropy increase. . On the other hand, when the number of the crystal grains is too large, the bending workability, the flexural anisotropy and the proof stress anisotropy are excellent, but the strength is lowered.

In particular, in the case of a narrow pin (for example, 0.25 mm width) for a microminiature connector made of the above-described copper alloy plate material, the area is within the range of the cube orientation {001} <100> crystal grain area ratio effective for improving the bending workability. Even if the rate is increased, if the average grain area of the cube-oriented crystal grains is large and the distribution of the cube-oriented crystal grains is non-uniform, the grains having an orientation other than the cube-oriented crystal grains during bending There is a high possibility that cracks will occur at the part. Also, anisotropy may occur depending on the bending direction. Therefore, in the crystal orientation analysis by the EBSD method, it is preferable that 40 or more and 100 or less cube-oriented crystal grains are distributed within 60 μm square and have equal dispersibility.
Therefore, in the copper alloy sheet of the present invention, the average crystal grain area and dispersibility of the cube-oriented crystal grains are controlled. Specifically, in the intermediate warm rolling before recrystallization solution heat treatment, heating to a temperature at which recrystallization does not occur, and rolling at a rolling rate of 5% or more at that temperature introduces strain throughout the rolled material. It is possible to control the opening to an appropriate state. Thereby, equal dispersibility of the cube orientation can be realized. At the same time, the average grain area of each crystal orientation can be controlled. By controlling the dispersibility, the bending workability of the narrow pin is enhanced, and the strength anisotropy such as the deflection anisotropy and the proof stress anisotropy is reduced.

Next, the auxiliary additive element added to the copper alloy sheet of the present invention will be described.
As described above, in a preferred embodiment, the copper alloy sheet material of the present invention includes Sn, Zn, Ag, Mn, B, P, Mg, Cr as secondary additive elements in addition to the main additive elements of Ni and Si. , Zr, Fe and Hf may be included, and the content thereof is 0.005% by mass or more and 1.0% by mass or less, and preferably 0% by total of the sub-addition elements. It is 0.01 mass% or more and 0.9 mass% or less, More preferably, it is 0.03 mass% or more and 0.8 mass% or less, Especially preferably, it is 0.05 mass% or more and 0.5 mass% or less. When the total amount of these sub-added elements is 1.0% by mass or less, it is difficult to cause an adverse effect of lowering the conductivity. Moreover, if it is the said range, the following addition effect will fully be utilized and electrical conductivity will not fall remarkably. If it is in the especially preferable range, a high addition effect and high electrical conductivity can be obtained. On the other hand, when the content of the secondary additive element is too small, the effect of addition is not sufficiently exhibited. On the other hand, when there is too much content of a secondary additive element, electrical conductivity becomes low and is not preferable. Below, the addition effect of each sub-addition element is demonstrated.

  Among the auxiliary additive elements, Mg, Sn, and Zn improve the stress relaxation resistance of the copper alloy sheet. The stress relaxation resistance is further improved by a synergistic effect when each of them is added together than when they are added alone. In addition, the solder embrittlement is remarkably improved. The stress relaxation resistance is measured under the conditions of 150 ° C. and 1000 hours in accordance with the Japan Electronic Materials Industries Association standard EMAS-3003. An initial stress of 80% of the proof stress is applied by the cantilever method, and the displacement after the test at 150 ° C. for 1000 hours is defined as the stress relaxation property.

  Among the auxiliary additive elements, Mn, Ag, B, and P improve the hot workability of the copper alloy sheet and improve the strength.

  Among the auxiliary additive elements, Cr, Zr, Fe, and Hf are finely precipitated on the base material as a compound or as a simple substance. As a simple substance, it preferably deposits at 75 nm to 450 nm, more preferably 90 nm to 400 nm, and particularly preferably 100 nm to 350 nm, which contributes to precipitation hardening. Moreover, it precipitates with the magnitude | size of 50 nm to 500 nm as a compound. In any case, there is an effect of making the crystal grain fine by suppressing the growth of the crystal grain, and bending workability is improved by improving the dispersion state of the crystal grain of the cube orientation {001} <100>. Improve well.

Next, the bending workability of the copper alloy sheet material of the present invention will be described.
Regarding the bending workability, it is preferable that a test piece subjected to 90 ° W bending is subjected to 180 ° contact bending using a compression tester, and no crack is generated at the apex of the bent portion.
In other words, the copper alloy sheet material of the present invention is cracked on the surface of the bending process by 180 ° U contact bending in a bending process of a narrow width of 1 mm or less as a bending processability in the rolling parallel direction and the rolling vertical direction. It is preferable that no occurs.

Next, the anisotropy of the deflection coefficient and the anisotropy of the proof stress will be described.
The difference between the deflection coefficient in the rolling parallel direction (//) and the deflection coefficient in the rolling vertical direction (⊥) is preferably 10 GPa or less in absolute value. In this case, the anisotropy of the deflection coefficient is small. The difference between the proof stress in the rolling parallel direction and the proof stress in the vertical direction of rolling is preferably 10 MPa or less in absolute value. In this case, the anisotropy of the proof stress is small.

Next, a preferred embodiment of the method for producing a copper alloy sheet according to the present invention will be described.
In order to produce the copper alloy plate material of the present invention, the ingot obtained by casting the copper alloy material is subjected to heat treatment (homogenization treatment) and hot rolling, and further formed into a thin plate by cold rolling, Intermediate annealing below the recrystallization temperature of the thin plate, and heating to 100 ° C. or more and 400 ° C. or less, followed by warm rolling (hereinafter referred to as intermediate warm rolling) with a rolling rate of 5% or more at that temperature, and thereafter. This is a production method in which an intermediate solution heat treatment for re-dissolving solute atoms in a thin plate is performed.
The copper alloy material is made of 1.0 to 5.0% by mass of Ni, 0.1 to 1.0% by mass of Si, and Sn, Zn, Ag, Mn, B, Containing at least one selected from the group consisting of P, Mg, Cr, Zr, Fe and Hf in a total of 0.005 mass% to 1.0 mass%, with the balance being composed of copper and inevitable impurities It is.

Here, the rolling rate is a value expressed as a percentage by dividing the value obtained by subtracting the cross-sectional area after rolling from the cross-sectional area before rolling by the cross-sectional area before rolling and multiplying by 100. That is, it is represented by the following formula.
[Rolling ratio] = {([Cross sectional area before rolling] − [Cross sectional area after rolling]) / [Cross sectional area before rolling]} × 100 (%)

Specifically, the following production method can be given as a preferred example.
The copper alloy material is cast [Step 1] to obtain an ingot. The ingot is subjected to homogenization heat treatment [Step 2], hot-rolled [Step 3], and then immediately cooled (for example, water-cooled and water-quenched) [Step 4]. Next, chamfering [Step 5] is performed to remove the oxide film on the surface. Thereafter, cold rolling [Step 6] is performed to obtain a thin plate by rolling to a rolling rate of 80% or more.
And after performing intermediate annealing [step 7] for 5 seconds to 20 hours at a temperature of 400 ° C. or more and 700 ° C. or less, which is a temperature at which the thin plate is partially recrystallized, after heating to 100 ° C. or more and 400 ° C. or less Intermediate warm rolling at a rolling rate of 5% or more and 50% or less is performed on the thin plate as intermediate warm rolling [step 8] under temperature.
Thereafter, an intermediate solution heat treatment [Step 9] for re-dissolving the solute atoms is performed. In the recrystallization texture of the thin plate in this intermediate solution heat treatment, the cube orientation area ratio increases.
After this intermediate solution heat treatment [Step 9], an aging precipitation heat treatment [Step 10], finish cold rolling [Step 11], and temper annealing [Step 12] are performed in this order.

On the other hand, in the conventional method for producing a precipitation-type copper alloy, a copper alloy material is cast [Step 1] to obtain an ingot, which is subjected to homogenization heat treatment [Step 2], hot rolling [Step 3], and cooling. (Water cooling) [Step 4], chamfering [Step 5], cold rolling [Step 6] are performed in this order to reduce the thickness. Then, after performing an intermediate solution heat treatment [Step 9] in a temperature range of 700 ° C. to 1000 ° C. to re-dissolve the solute atoms, an aging precipitation heat treatment [Step 10] and finish cold rolling [Step 11] and necessary Thus, the required strength is satisfied by temper annealing [Step 12]. In this series of steps, the texture of the material is roughly determined by recrystallization that occurs during the intermediate solution heat treatment, and finally determined by the orientation rotation that occurs during finish rolling.
Compared with the production method of the present invention, the two steps of the intermediate annealing [Step 7] and the intermediate warm rolling [Step 8] have not been performed conventionally.

Next, an embodiment in which the conditions of each step in the production method of the present invention are set in more detail will be described.
In casting [step 1], at least Ni is contained in an amount of 1.0% by mass or more and 5.0% by mass or less, Si is contained in an amount of 0.1% by mass or more and 1.0% by mass or less, and other auxiliary additive elements are necessary. The element is mixed so that it is contained appropriately, and the alloy material consisting of Cu and inevitable impurities is melted in a high-frequency melting furnace, and this is cooled at a cooling rate of 0.1 ° C./second to 100 ° C./second. Get an ingot. The ingot is subjected to a homogenization heat treatment [Step 2] at 800 ° C. or higher and 1020 ° C. or lower for 3 minutes to 10 hours. Thereafter, hot rolling [Step 3] is performed, and further water quenching (corresponding to cooling [Step 4]) is performed. Then, the oxide film is removed by chamfering [Step 5]. Thereafter, cold rolling [Step 6] at a rolling rate of 80% to 99.8% is performed to obtain a thin plate.

  Next, intermediate annealing is performed at 400 ° C. to 700 ° C. for 5 seconds to 20 hours [Step 7]. Further, after heating under the conditions of 100 ° C. to 400 ° C., the rolling rate is 5% to 50%. Intermediate warm rolling [Step 8] is performed. Here, warm rolling means rolling at a temperature of 100 ° C. or more and 400 ° C. or less.

Thereafter, an intermediate solution heat treatment [Step 9] is performed at 600 ° C. to 1000 ° C. for 5 seconds to 1 hour. Thereafter, preferably an aging precipitation heat treatment [Step 10] for 5 minutes to 10 hours at 400 ° C. or higher and 700 ° C. or lower in an inert gas atmosphere such as nitrogen or argon, and finish cooling with a rolling rate of 3% or higher and 25% or lower. Cold rolling [Step 11] and temper annealing [Step 12] at 200 ° C. to 600 ° C. for 5 seconds to 10 hours are performed in this order to obtain the copper alloy sheet material of the present invention.
In the production method of the present invention, when there is no particular need for the properties of the obtained plate material, 1 of each step of the face milling [Step 5], finish cold rolling [Step 11], and temper annealing [Step 12]. It is not necessary to omit one or more.

  In this embodiment, in the hot rolling [Step 3], in the temperature range of 700 ° C. or higher and the reheat temperature (1020 ° C.) or lower, processing for breaking the cast structure and segregation into a uniform structure, Processing for crystal grain refinement is performed.

In the intermediate annealing [Step 7], heat treatment is performed to such an extent that the entire structure in the alloy is not recrystallized. Thereafter, it is heated to a temperature range not recrystallizing, preferably 100 ° C. or more and 400 ° C. or less, more preferably 120 ° C. or more and 380 ° C. or less, particularly preferably 140 ° C. or more and 360 ° C. or less, and at that temperature, preferably 5% Intermediate warm rolling [Step 8] is performed at a rolling rate of 50% or less, more preferably 7% or more and 45% or less, and particularly preferably 10% or more and 40% or less, to control the introduction and release of processing strain.
If the rolling rate in the intermediate warm rolling [Step 8] is too low, the working strain is small, the crystal grains become coarse in the intermediate solution heat treatment [Step 9] in the next step, the bending wrinkles become large, and the characteristics are inferior. On the other hand, if the rolling rate in the intermediate warm rolling [Step 8] is too high, the cube orientation grown in the recrystallization solution heat treatment [Step 9] rotates to another orientation, and the cube orientation area ratio decreases. Further, when the heating temperature in the intermediate warm rolling [Step 8] is lower than 100 ° C., the release of processing strain is reduced, and conversely, when the heating temperature is higher than 400 ° C., the release of processing strain proceeds and recrystallization proceeds. Therefore, in the intermediate solution heat treatment [Step 9] in the next step, the uniform dispersibility of the cube-oriented crystal grains due to strain-induced grain boundary movement becomes insufficient. As a result, in both cases where the heating temperature in intermediate warm rolling [Step 8] is too high or too low, bending anisotropy as bending anisotropy and proof anisotropy as strength anisotropy Occurs.

  In the intermediate solution heat treatment [Step 9], the cube orientation area ratio increases in the recrystallized texture. Here, when the heat treatment temperature of the intermediate annealing [Step 7] before the intermediate solution heat treatment [Step 9] is higher than the temperature in the above range, an oxide film is formed, which is not preferable. For this reason, the heat treatment temperature in this intermediate annealing [Step 7] is preferably 400 ° C. or more and 700 ° C. or less. In particular, it is difficult to uniquely determine, but by setting the heat treatment temperature to the above temperature range in the intermediate annealing [Step 7], the cube orientation area ratio tends to increase in the intermediate solution heat treatment [Step 9]. .

  After the intermediate solution heat treatment [Step 9], an aging precipitation heat treatment [Step 10], finish cold rolling [Step 11], and temper annealing [Step 12] are performed. In order to increase the cube orientation area ratio due to strain-induced grain boundary migration in the recrystallized texture formed in the intermediate solution heat treatment [Step 9], a predetermined process may be performed in the intermediate warm rolling [Step 8]. It is valid. In addition, by controlling the crystal orientation in a certain direction in the intermediate warm rolling [Step 8], it contributes to the development of cube-oriented crystal grains. Furthermore, the mechanical strength can be increased by precipitation strengthening by precipitating the additive element from the solid solution by performing the aging precipitation heat treatment [Step 10]. Moreover, you may finally adjust plate | board thickness by performing finish cold rolling [process 11]. Furthermore, you may finally adjust the tempering of a board | plate material by performing temper annealing [process 12].

  Further, further processing strain is added by cold rolling [step 6], heat treatment is performed at 400 ° C. to 700 ° C. for 5 seconds to 20 hours in intermediate annealing [step 7], and further intermediate warm rolling [step 8]. As a result, the cube orientation area ratio is remarkably increased in the recrystallized texture in the intermediate solution treatment [Step 9].

  The intermediate annealing [Step 7] is intended to obtain a sub-annealed structure that is not completely recrystallized but partially recrystallized. In the intermediate warm rolling [Step 8], the purpose is to promote the introduction and release of microscopically non-uniform strain by rolling at a heating temperature of 100 ° C. to 400 ° C. and a rolling rate of 5% or more. .

  The effect of the intermediate annealing [Step 7] and the intermediate warm rolling [Step 8] enables the growth of the cube orientation crystal grains, the refinement of the cube orientation crystal grains, and the equal dispersion in the intermediate solution treatment [Step 9]. . In intermediate warm rolling [Step 8], strain is introduced by rolling and strain is released by heating. By appropriately controlling both of these, strain induction of intermediate solution heat treatment [Step 9] is induced. Development of cube-oriented crystal grains due to grain boundary movement, refinement of cube-oriented crystal grains, and equal dispersibility can be improved. In other words, by introducing strain, the cube-oriented crystal grains can be developed, and by releasing the strain, the cube-oriented crystal grains can be refined and equidispersed. In the conventional normal method, the main purpose of the heat treatment such as the intermediate solution treatment [Step 9] is to recrystallize the material and reduce the strength in order to reduce the load in the next step. Its purpose is completely different.

  Although there is no restriction | limiting in particular in the board thickness of the copper alloy board | plate material of this invention, Usually, it is 0.03-0.50 mm, Preferably, it is 0.05-0.35 mm.

The copper alloy sheet material of the present invention preferably satisfies the following requirements and satisfies, for example, the following characteristics required for a copper alloy sheet material for connectors.
One of the characteristics of the bending workability is that the bending surface portion is preferably free from cracks in the 180 ° contact U-bending test. The detailed conditions are as described in the examples.
One deflection coefficient of the characteristics is preferably 130 GPa or less. The detailed conditions are as described in the examples. Although there is no restriction | limiting in particular in the lower limit of the bending coefficient which the copper alloy board | plate material of this invention shows, Usually, it is 90 GPa or more.
One proof stress of the characteristic is preferably 700 MPa or more. More preferably, it is 750 MPa or more. The detailed measurement conditions are as described in the examples. Although there is no restriction | limiting in particular in the upper limit of the yield strength which the copper alloy board | plate material of this invention shows, Usually, it is 900 Mpa or less.
One of the characteristics of the conductivity is preferably 5% IACS (International Annealed Copper Standard) or more. More preferably, it is 10% IACS or more, and particularly preferably 20% IACS or more. The detailed measurement conditions are as described in the examples. Although there is no restriction | limiting in particular in the upper limit of the electrical conductivity which the copper alloy board | plate material of this invention shows, Usually, it is 50% IACS or less.

  Hereinafter, the present invention will be described in more detail based on examples, but the present invention is not limited thereto.

(Examples 1-14 and Comparative Examples 1-4)
Each of the alloys shown in Table 1 containing Ni, Si, and secondary additive elements, with the balance consisting of Cu and inevitable impurities, was melted in a high-frequency melting furnace, and this was dissolved at 0.1 ° C./sec to 100 ° C. / After cooling at a cooling rate of 2 seconds, casting [Step 1] was performed to obtain an ingot.
This ingot is subjected to a homogenization heat treatment [Step 2] at 800 ° C. or higher and 1020 ° C. or lower for 3 minutes to 10 hours, and then hot-rolled as hot working at 700 ° C. or higher and below the reheating temperature (1020 ° C.) [Step 3] and water quenching (equivalent to cooling [step 4]) to obtain a hot rolled sheet. Next, the surface of the hot-rolled sheet was chamfered [Step 5] to remove the oxide film. Thereafter, cold rolling [Step 6] at a rolling rate of 80% to 99.8% was performed to obtain a thin plate.
Next, intermediate annealing of the thin plate is performed by heat treatment at 400 ° C. to 700 ° C. for 5 seconds to 20 hours [Step 7], and after heating to 100 ° C. to 400 ° C., the temperature is 5% to 50%. Intermediate warm rolling [Step 8] was performed at a rolling rate.
Thereafter, an intermediate solution treatment [Step 9] was performed at 600 ° C. to 1000 ° C. for 5 seconds to 1 hour. Next, an aging precipitation heat treatment [Step 10] is performed for 5 minutes to 1 hour at 400 ° C. or higher and 700 ° C. or lower in an inert gas atmosphere, and cold rolling is finished at a rolling rate of 3% to 25% [Step 11]. The temper annealing [Step 12] was performed at 200 ° C. to 600 ° C. for 5 seconds to 10 hours to prepare copper alloy sheet materials (Examples 1 to 14 and Comparative Examples 1 to 4). The final plate thickness of each test material was 0.08 mm.

The compositions and characteristics of Examples 1 to 14 and Comparative Examples 1 to 4 are as shown in Table 1 and Table 2.
After each heat treatment and rolling, acid cleaning and surface polishing were performed according to the state of oxidation and roughness of the material surface, and correction with a tension leveler was performed according to the shape. Moreover, the processing temperature in the hot processing [Step 3] was measured by a radiation thermometer installed on the entry side and the exit side of the rolling mill.

The following characteristics were investigated for each sample material.
(A) Cube orientation area ratio A measurement area of 0.09 mm ² (300 μm × 300 μm) was measured by the EBSD method under the condition that the scan step was 0.1 μm. In this measurement area, 60 μm × 60 μm is one block, and a total of 25 blocks (5 blocks × 5 blocks) can be measured in one field of view. The scan step in this case was set to a 0.1 μm step as described above in order to measure fine crystal grains. In the analysis, the EBSD measurement result in the measurement area of 300 μm × 300 μm is divided into the 25 blocks described above, and the cube orientation area ratio of each block, the average crystal grain area, the number of crystal grains, and the base material including the cube orientation grains The average grain area was confirmed. The electron beam was generated from thermionic electrons from a tungsten filament of a scanning electron microscope.

(B) 180 degree adhesion U bending test It processed by the punching with a press so that a width | variety may be set to 0.25 mm perpendicularly to a rolling direction, and length may be 1.5 mm. The JIS (Good Way) is W-bent so that the axis of bending is perpendicular to the rolling direction, and BW (Bad Way) is W-bent so that it is parallel to the rolling direction. After 90 ° W bending in accordance with standard JCBA-T307 (2007), 180 ° contact bending was performed without an inner radius using a compression tester. The bent surface was observed with a 100 × scanning electron microscope to investigate the presence of cracks. Those having no cracks were represented by “◯ (good)”, and those having cracks were represented by “× (poor)”. As for the size of the crack, the maximum width is 30 μm to 100 μm, and the maximum depth is 10 μm or more.

(C) Deflection coefficient The test piece was processed by punching with a press so that the width was 0.25 mm perpendicular to the rolling direction and the length was 1.5 mm parallel to the rolling direction. The front and back of the test piece were measured 10 times each with a cantilever beam, and the average value was shown.
The deflection coefficient E (GPa) is expressed by the following formula (1).
E = 4a / b × (L / t) ³ (1)
Here, a is the gradient of the displacement f and stress w, b is the width of the specimen, L is the distance between the fixed end and the load point, and t is the thickness of the specimen.
In this test, the anisotropy of deflection in the rolling parallel direction and the rolling vertical direction was confirmed.

(D) Yield strength [Y]
In the measurement of the deflection coefficient, the yield strength Y (MPa) was calculated from the following formula (2) from the indentation amount (displacement) up to the elastic limit of each test piece.
Y = {(3E / 2) × t × (f / L) × 1000} / L (2)
E is the deflection coefficient, t is the plate thickness, L is the distance between the fixed end and the load point, and f is the displacement (indentation depth).
In this test, the anisotropy of the proof stress in the rolling parallel direction and the rolling vertical direction was confirmed.

(E) Conductivity [EC]
The specific resistance was measured by a four-terminal method in a thermostat kept at 20 ° C. (± 0.5 ° C.) to calculate the conductivity. In addition, the distance between terminals was 100 mm.

For Examples 1 to 14 and Comparative Examples 1 to 4 of the present invention, the main raw material Cu, Ni, Si, and auxiliary additive elements were blended, dissolved, and cast so as to have the compositions shown in Table 1.
As shown in Table 2, under the production conditions of Examples 1 to 14, the intermediate warm rolling [Step 8] was performed at a rolling rate of 5% or more after heating to 100 ° C. or more and 400 ° C. or less. Tissue, 50% cube orientation area ratio of 5% or more of Example 14 from Example 1 below, the average grain area of cube orientation grains 1.8 .mu.m ² or more 45.0Myuemu ² or less, 1 block (60 [mu] m × 60 [mu] m The number of cube-oriented crystal grains per unit area) was 40 to 100, and the average crystal grain area of the base material including the cube-oriented grains was 50 μm ² or less. With respect to the characteristics of Examples 1 to 14, all showed excellent results of 180 ° U-contact bending, deflection anisotropy, and proof stress anisotropy.
In Comparative Example 1 to Comparative Example 4, the case of not satisfying the stipulation in the production method of the present invention did not satisfy the cube orientation area ratio and the number of cube orientation grains per block.

As shown in Tables 1 and 2, the scope of the present invention, that is, Ni is 1.0 mass% or more and 5.0 mass% or less, Si is 0.1 mass% or more and 2.0 mass% or less, Sn if necessary. Contains at least one selected from the group consisting of Zn, Ag, Mn, B, P, Mg, Cr, Zr, Fe and Hf in a total of 0.005% by mass to 1.0% by mass, with the balance being copper and In the crystal orientation analysis by the electron backscattering diffraction method, the area ratio of the cube orientation {001} <100> is 5% or more and 50% or less in addition to these, preferably in addition to the cube orientation. characteristics of the average grain area of crystal grains is at 1.8 .mu.m ² or more 45.0Myuemu ² or less, if the further satisfy the average crystal grain area of crystal grains of the base material is 50 [mu] m ² or less, the bending having , Characteristics of deflection coefficient, Any of the properties of the force was good. In the bending characteristics, no crack occurred at the top of the bend. Further, in the characteristics of the deflection coefficient, the anisotropy of the deflection coefficient was within 10 GPa, and in the characteristics of the proof stress, the proof stress anisotropy was within 10 MPa, both of which were small.
Therefore, the copper alloy plate material of the present invention can be provided as a copper alloy plate material suitable for a lead frame, a connector, a terminal material, etc. for an electric / electronic device, a connector, a terminal material, a relay, a switch, etc. for automobile use. it can.

Further, as shown in Table 2, any of the characteristics was inferior in the sample of the comparative example.
That is, Comparative Examples 1, 2, and 4 were inferior in the BW bending characteristics, the deflection coefficient anisotropy, and the proof stress anisotropy because the average crystal grain area of the cube-oriented crystal grains was too large. Comparative Example 3 was inferior in bending characteristics (GW, BW), flexural anisotropy and proof stress anisotropy because the cube orientation area ratio was too small.
The conductivity was 30 to 45% IACS in all cases.

(Conventional example)
The alloy composition shown in the following Table 3 (the balance is copper (Cu)) is the same as in Example 1 except that heating is not performed in intermediate annealing [Step 7] and intermediate warm rolling [Step 8]. Thus, a copper alloy sheet was produced. The test material of the copper alloy sheet obtained as a result was evaluated in the same manner as in Example 1. The results are shown in Table 4.

As is apparent from Tables 3 and 4, the alloy composition defined in the present invention is not satisfied, intermediate annealing [Step 7] is not performed, and heating in the subsequent intermediate warm rolling [Step 8] is not performed. Even if the produced copper alloy sheet materials of the conventional examples 1 and 2 adopt manufacturing conditions (each process and conditions) other than these two processes, the average crystal grain area of the cube orientation is large in each block. The number of cube grains is small, and the anisotropy of the deflection coefficient and the proof stress is large.
Further, the copper alloy sheet material of Conventional Example 3 that satisfies the alloy composition defined in the present invention, but is produced without performing intermediate annealing [Step 7] and without subsequent heating in intermediate warm rolling [Step 8]. Even if the manufacturing conditions other than these two steps (each step and conditions) are adopted, the average crystal grain area in the cube orientation is large, the number of cube grains per block is small, and the bending characteristics It is inferior to (BW), and the anisotropy of the deflection coefficient and the proof stress is large.

  Separately from these, in order to clarify the difference from the copper alloy sheet material according to the present invention for the copper alloy sheet material produced under the conventional production conditions, a copper alloy sheet material was produced under the conventional production conditions, and the same as described above. The characteristic items were evaluated. In addition, the processing rate was adjusted so that the thickness of each board | plate material might become the same thickness as the said Example unless there is particular notice.

(Comparative Example 101) ... JP 2011-162848 A Condition of Invention Example 1 3.2 mass% Ni, 0.7 mass% Si, 1.0 mass% Zn, 0.2 mass% A copper alloy composed of Sn was melted and cast. The obtained ingot is subjected to face grinding, hot rolling is performed so that the end temperature becomes 550 to 850 ° C. after homogenization heat treatment, and after rapid cooling by water cooling, the surface oxide layer is removed by mechanical polishing (face grinding). )did. Next, after cold rolling to a predetermined plate thickness, cold rolling is further performed at a processing rate of 90% or more, and heating is performed at a heating rate of 0.1 ° C./s or less to a temperature of 800 to 900 ° C. The solution treatment was performed.
Next, an aging treatment was performed at 500 ° C. The aging treatment time was adjusted to a time when the hardness reached a peak due to aging at a temperature of 460 ° C. according to the composition of the copper alloy. As for the aging treatment time, an optimum aging treatment time was determined by a preliminary experiment according to the composition of the alloy of Example 1 of the present invention.
Next, the plate material after the aging treatment was further subjected to finish cold rolling at a rolling rate of 40%. Further, low-temperature annealing was performed at 480 ° C. for 30 seconds. In addition, grinding | polishing and chamfering were performed in the middle as needed, and plate | board thickness was arranged to 0.10 mm.
This was designated as sample c01.

The obtained specimen c01 was not subjected to intermediate annealing [Step 7] as compared with the above-described example according to the present invention, and was not heated at the heating temperature before solution heat treatment [Step 9]. Intermediate warm rolling [Step 8] is also not performed. Further, since the temperature increase rate of the solution heat treatment was slow, the grain growth became remarkable near the ultimate temperature, and the crystal grains became coarse. In the obtained structure, the area of the cube-oriented crystal grains was as large as 150 μm ² or more. Moreover, the anisotropy of the deflection coefficient and the strength was also greater than 10 GPa and greater than 15 MPa, respectively, and the results did not satisfy the required characteristics in the present invention.

(Comparative Example 102) ... Conditions of Examples 1 and 4 of JP2011-12321A Copper alloy having a composition composed of 2.8 mass% Ni and 0.9 mass% Si (Example of the publication) 1), and a copper alloy having a composition of 2.8% by mass of Ni, 0.9% by mass of Si, 0.1% by mass of Zn, 0.1% by mass of Mg, and 0.1% by mass of Sn ( Each alloy of Example 4) of the publication is melted in the atmosphere under a charcoal coating in a coreless furnace (high frequency induction melting furnace), cast into a mold surrounded by a copper mold on four sides, a thickness of 250 mm, a width of 620 mm, An ingot having a length of 2500 mm was produced.
Next, a SUS rod having a diameter of 3 mm was inserted in the vertical direction from the molten metal surface at the upper end of the mold at the intersection of the position of the width 155 mm and the thickness 125 mm of the mold, and the depth of the unsolidified portion was measured. A value obtained by subtracting the mold length (copper mold length) from the depth of the obtained unsolidified portion was defined as the distance from the mold lower end depth to the solidification end depth. Specifically, they were 300 mm (Example 1 of the publication) and 260 mm (Example 4 of the publication). The casting speed was adjusted in the range of 50 to 200 mm / min so that this distance was 250 mm or more, and casting was performed to obtain an ingot.
A 250 × 620 × 300 mm block of a stationary part was cut out from the obtained ingot, and a slice (250 × 15 × 300 mm) having a cross section parallel to the casting direction was collected from a central part of 620 mm width. This was immersed in nitric acid for 0.5 to 1 hour, and the direction of the [100] axis of the columnar crystal was obtained from the macrostructure obtained by etching. The angle at which the plane perpendicular to the casting direction and the direction of the [100] axis of the columnar crystal intersect was measured. Specifically, they were 13 ° (Example 1 of the publication) and 11 ° (Example 4 of the publication).
Further, after the ingot is homogenized, the temperature is adjusted to 500 to 1000 ° C., rolling is performed at a total processing rate of 60 to 96%, and then the obtained rolled material is directly cooled with water to form a coil having a thickness of about 10 mm. . The surface of the rolled material was milled to remove oxide scale. At this time, the ratio of the cube orientation of the rolled material was set to 5 to 95%. Then, cold rolling at a working rate of 85 to 99.8%, solution heat treatment at 700 to 1020 ° C. for 5 seconds to 1 hour, finish cold rolling at a working rate of 1 to 60%, and 200 to 600 ° C. for 5 seconds to The temper annealing for 10 hours was performed in the order of description, and a specimen having a thickness of 0.15 mm was obtained.
These were designated as sample d01 (Example 1 of the publication) and d02 (Example 4 of the publication), respectively.

The obtained specimens d01 and d02 were not subjected to the intermediate annealing [Step 7] as compared with the above-described examples according to the present invention, and were subjected to the heating temperature before the solution heat treatment [Step 9]. Also, the intermediate warm rolling in [Step 8] is not performed. In the obtained structure, the area ratio of the cube-oriented crystal grains was 35% in the sample d01 (Example 1 of the publication) and 7% in the sample d02 (Example 4 of the publication), respectively. becomes remarkable, 254 micrometers ² and the sample d02 (example 4 of the publication) the average grain area of each sample d01 grain laden base material of cube orientation (example 1 of the publication) in 201Myuemu ² coarse It was something. Moreover, the anisotropy of the deflection coefficient and the strength was also greater than 10 GPa and greater than 15 MPa, respectively, and the results did not satisfy the required characteristics in the present invention.

  While this invention has been described in conjunction with its embodiments, we do not intend to limit our invention in any detail of the description unless otherwise specified and are contrary to the spirit and scope of the invention as set forth in the appended claims. I think it should be interpreted widely.

  This application claims priority based on Japanese Patent Application No. 2011-102996, filed in Japan on May 2, 2011, which is incorporated herein by reference. Capture as part.

Claims (6)

Ni is contained in an amount of 1.0% by mass or more and 5.0% by mass or less, Si is contained in an amount of 0.1% by mass or more and 2.0% by mass or less, and the balance is composed of copper and inevitable impurities.
In the crystal orientation analysis by the electron backscatter diffraction method, the area ratio of crystal grains having an orientation whose deviation from the cube orientation {001} <100> is within 15 ° is 5% or more and 50% or less, and the cube orientation {001 } A copper alloy plate material, wherein crystal grains having an orientation with a deviation from <100> within 15 ° are dispersed in a range of 40 to 100 in a 60 μm square. Ni is 1.0 mass% or more and 5.0 mass% or less, Si is 0.1 mass% or more and 2.0 mass% or less, Sn, Zn, Ag, Mn, B, P, Mg, Cr, Zr, Fe and Containing at least one selected from the group consisting of Hf in a total of 0.005% by mass or more and 1.0% by mass or less, with the balance being composed of copper and inevitable impurities,
In the crystal orientation analysis by the electron backscatter diffraction method, the area ratio of crystal grains having an orientation whose deviation from the cube orientation {001} <100> is within 15 ° is 5% or more and 50% or less, and the cube orientation {001 } A copper alloy plate material, wherein crystal grains having an orientation with a deviation from <100> within 15 ° are dispersed in a range of 40 to 100 in a 60 μm square. cube orientation {001} copper alloy according to claim 1 or 2, the average grain area of crystal grains is 1.8 .mu.m ² or more 45.0Myuemu ² or less with orientation deviation is within 15 ° from the <100> Board material. The copper alloy sheet according to any one of claims 1 to 3, wherein an average crystal grain area of crystal grains of the base material is 50 µm ² or less.   The difference between the deflection coefficient in the rolling parallel direction and the deflection coefficient in the rolling vertical direction is 10 GPa or less in absolute value, and the difference between the proof stress in the rolling parallel direction and the proof stress in the rolling vertical direction is 10 MPa or less in absolute value. The copper alloy sheet material according to any one of the above items. An ingot obtained by casting a copper alloy material is subjected to homogenization heat treatment and hot rolling, further formed into a thin plate by cold rolling, and then subjected to intermediate solution heat treatment to re-dissolve the solute atoms in the thin plate. A method for producing a copper alloy sheet,
The copper alloy material has an alloy composition of the copper alloy sheet according to claim 1 or 2,
The homogenization heat treatment is performed at 800 ° C. or more and 1020 ° C. or less for 3 minutes to 10 hours,
After performing the cold rolling at a rolling rate of 80% or more and 99.8% or less, intermediate annealing is performed for 5 seconds to 20 hours at a temperature of 400 ° C. or more and 700 ° C. or less which is less than the recrystallization temperature,
Further, after heating to 100 ° C. or more and 400 ° C. or less and performing an intermediate warm rolling at a rolling rate of 5% or more and 50% or less at that temperature,
The intermediate solution heat treatment is performed at 600 to 1000 ° C. for 5 seconds to 1 hour,
A method for producing a copper alloy sheet comprising the steps of performing an aging precipitation heat treatment at 400 ° C. to 700 ° C. for 5 minutes to 10 hours in this order.

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