JP4948678B2 - Copper alloy sheet, connector using the same, and copper alloy sheet manufacturing method for manufacturing the same - Google Patents

Description

  The present invention relates to a copper alloy plate material, and more specifically, a copper alloy plate material applied to lead frames, connectors, terminal materials, relays, switches, sockets, etc. for in-vehicle components and electrical / electronic devices, and a connector using the same, and The present invention relates to a method for producing a copper alloy sheet for producing the same.

Copper alloy sheet materials used for applications such as lead frames, connectors, terminal materials, relays, switches, sockets, etc. for automotive parts and electrical / electronic equipment are characterized by electrical conductivity, yield strength (yield stress), and tensile properties. Strength, bending workability, and stress relaxation resistance are required. In recent years, the level required for these characteristics has increased with the reduction in size, weight, functionality, and high-density mounting of electric and electronic devices and the increase in the use environment. Some typical cases are shown.
In view of the reduction of mineral resources and the weight reduction of parts, the material is becoming thinner, and in order to maintain the spring contact pressure, a material having higher strength than the conventional material is used. At that time, since bending workability is generally in a trade-off relationship with strength, when a high-strength material is processed with a conventional bending radius, there is a problem that cracks occur. In particular, in-vehicle terminals and connectors for use in electronic devices often require a U-shaped bend design of 180 °. However, since a large stress is applied to the outside of the bent portion, a material with poor bending workability is used. Cracks occur, and conduction failure due to a decrease in connector contact pressure becomes a problem. As countermeasures, there are cases where a plurality of notches are made on the inner side to bend 180 °, or a design change that increases the inner bending radius from the design of close contact bending, etc., but the bending part design reduces the press cost. There is a problem that it cannot be compatible with downsizing of electronic device parts.
In addition, the use environment is increasing in temperature. For example, in automobile parts, the body weight has been reduced in order to reduce the amount of carbon dioxide generated, and electronic devices such as ECUs for engine control, which have been installed on doors in the past, are installed in the engine room or near the engine. The movement to shorten the wire harness between the electronic device and the engine is progressing. In addition, when the use of high current increases with the shift to electric vehicles, Joule heat becomes a problem. When the contact material used for the connector is lengthened to a high temperature of 100 ° C. or higher, the displacement within the elastic limit becomes a plastic displacement, and there is a problem that the contact pressure of the terminal fitting portion is lowered. Therefore, development of a copper alloy sheet material excellent in stress relaxation resistance is desired.
In order to solve the above problems, there is a demand for a copper alloy material that is excellent in stress relaxation resistance and has improved bending workability.

Several proposals have been made to solve the demand for improving the bending workability of the copper alloy material by controlling the crystal orientation.
In Patent Document 1, in a Cu—Ni—Si based copper alloy, the crystal grain size and the X-ray diffraction intensity from the {311}, {220}, {200} planes satisfy a certain condition. It has been found that bending workability is excellent. Further, in Patent Document 2, 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. Has been found. In Patent Document 3, it has been found that in a Cu—Ni—Si based copper alloy, bending workability is excellent by appropriately controlling the ratio of the Cube orientation {100} <001>.
In addition, in response to the demand for improved stress relaxation resistance, generally, the larger the crystal grain size, the more difficult it is to relax the stress. Patent Document 4 and the like show that both the bending workability and the bending workability are compatible.

JP 2006-009137 A JP 2008-013836 A JP 2006-283059 A JP 2008-106356 A

  By the way, in the inventions described in Patent Documents 1, 2, and 4, the measurement of crystal orientation by X-ray diffraction from a specific surface is performed by measuring only a part of specific surfaces in a distribution of crystal orientation having a certain spread. It is only related to Moreover, only the crystal plane in the plate surface direction is measured, and since it has not been evaluated which crystal plane is oriented in the rolling direction or the plate width direction, the control of the crystal orientation is insufficient, In some cases, the improvement of bending workability was insufficient. Further, in the X-ray measurement of the plate surface shown in these documents, since the penetration length of the X-ray is several tens of microns, the internal crystal orientation has not been controlled. In the invention described in Patent Document 3, the effectiveness of the Cube orientation is pointed out, but the distribution in the plate thickness direction and other crystal orientation components were not controlled. As described above, in the prior art, the improvement in bending workability may be insufficient, and in particular, the level at which bending can be performed without cracking at a high stress of 180 ° contact bending may be insufficient.

  In view of the problems as described above, the object of the present invention is to provide excellent bending workability, excellent strength, excellent stress relaxation resistance, lead frames for electrical / electronic devices, connectors, terminal materials, etc. Another object of the present invention is to provide a copper alloy sheet material suitable for connectors, terminal materials, relays, switches and the like for automobiles. Moreover, it aims at provision of the manufacturing method of the connector using the said copper alloy board | plate material, and the copper alloy board | plate material which manufactures this suitably.

  The present inventors have made various studies, studied copper alloys suitable for electric / electronic component applications, and controlled the plate thickness surface layer and the Cube orientation area ratio at 1/4 position of the plate thickness to obtain 180 °. It has been found that the close contact bending characteristics can be remarkably improved, and that the above problem can be solved by controlling the crystal grain size within a specific range. It has also been found that the reduction of the Brass orientation further contributes to bending workability. In addition, it has been found that the use of a specific additive element in the copper alloy can improve strength and stress relaxation characteristics without impairing electrical conductivity and bending workability. The present inventors have made the present invention based on these findings.

That is, the present invention provides the following means.
(1) A plate material comprising a copper alloy composition containing 0.5 to 5.0 mass% in total of at least one of Ni and Co, 0.1 to 1.2 mass% of Si, and the balance of Cu and inevitable impurities. Then, in the crystal orientation analysis in the electron backscattering diffraction measurement, the area ratio of the Cube orientation {0 0 1} <1 0 0> of the material surface layer is W0, and the Cube at the 1/4 position of the whole at the depth position of the material. When the orientation area ratio is W4, the ratio of W0 / W4 is 0.8 to 1.5, W0 is 5 to 48%, and the average crystal grain size is 12 to 100 μm, 180 ° Copper alloy sheet with excellent adhesion bending workability and stress relaxation resistance.
(2) Further, 0.005 to 2.0 mass% in total of at least one selected from the group consisting of Sn, Zn, Ag, Mn, B, P, Mg, Cr, Fe, Ti, Zr, and Hf is contained. The copper alloy sheet according to (1).
(3) The copper alloy sheet material according to (1) or (2), wherein the area ratio of the Brass orientation {1 1 0} <1 1 2> is 20% or less.
(4) A connector comprising the copper alloy sheet according to any one of (1) to (3).
(5) A method for producing a copper alloy sheet according to any one of (1) to (3),
After the copper alloy ingot having the composition described in (1) or (2) is subjected to at least the following steps I, II, III , IV , and V in that order, the processing rate is 5 to 40%. A method for producing a copper alloy sheet material comprising performing finish rolling.
[Step I: Hot rolling step with a pass processing rate of 30% or less and a holding time between passes of 20 to 30 seconds]
[Step II: Cold rolling step with a processing rate of 80% to 99%]
[Step III: An intermediate heat treatment step at a temperature of 300 to 700 ° C. for 10 seconds to 5 hours and a cold rolling step performed thereafter at a processing rate of 5 to 50%]
[Step IV: Solution heat treatment step performed at 800 to 1000 ° C.]
[Step V: Aging precipitation heat treatment step at 350 to 600 ° C. for 5 minutes to 20 hours and finish cold rolling step with a processing rate of 5 to 40%]

  The copper alloy sheet material of the present invention is excellent in bending workability and has excellent strength, such as lead frames, connectors and terminal materials for electric and electronic equipment, connectors and terminal materials for automobiles, relays, switches, etc. It is suitable for. Moreover, according to the manufacturing method of the copper alloy plate material of this invention, the copper alloy plate material which has said outstanding characteristic can be manufactured suitably.

It is explanatory drawing which showed the calculation method of the rotation angle from Cube azimuth | direction. It is explanatory drawing of the test method of the stress relaxation characteristic in an Example, (a) shows the state before heat processing, (b) shows the state after heat processing, respectively.

A preferred embodiment of the copper alloy sheet material of the present invention will be described in detail. Here, the “copper alloy material” means a material obtained by processing a copper alloy material into a predetermined shape (for example, a plate, a strip, a foil, a bar, a wire, or the like). Among them, the plate material refers to a material having a specific thickness and stable in shape and having a spread in the surface direction, and in a broad sense, includes a strip material. Here, in the plate material, “material surface layer” means “plate surface layer”, and “material depth position” means “position in the plate thickness direction”. The thickness of the plate material is not particularly limited, but it is preferably 8 to 800 μm, and more preferably 50 to 70 μm, considering that the effects of the present invention are better manifested and suitable for practical applications.
In addition, although the copper alloy plate material of this invention prescribes | regulates the characteristic with the integration rate of the atomic surface in the predetermined direction of a rolled sheet, this should just have such a characteristic as a copper alloy plate material. Therefore, the shape of the copper alloy sheet is not limited to a sheet or a strip, and in the present invention, the pipe can be interpreted and handled as a sheet.

(Regulation by EBSD measurement)
In order to clarify the cause of the occurrence of cracks during bending of the material, the present inventors analyzed the metal structure of the cross section after bending deformation by an electron microscope and electron backscatter diffraction measurement (hereinafter also referred to as EBSD). We investigated in detail. As a result, it was observed that the base material was not uniformly deformed, but non-uniform deformation progressed, in which the deformation was concentrated only in a region having a specific crystal orientation. Then, it was found that due to the non-uniform deformation, wrinkles and cracks having a depth of several μm were generated on the surface of the base material after bending.
Furthermore, in 90 ° bending, strain is applied to the outermost layer in the plate thickness direction, whereas in 180 ° bending, not only the outermost layer in the plate thickness direction of the thin plate but also greatly distorted to the position of the plate thickness ¼, It was found that not only the crystal grains in the vicinity of the surface layer but also the crystal grains up to the depth of the plate thickness ¼ position are involved in the local deformation region developed from the surface layer. And the local deformation | transformation zone | band was not observed so much in Cube direction grain, and it turned out that Cube direction has the effect which suppresses nonuniform deformation. As a result, it was found that wrinkles generated on the plate surface were reduced and cracks were suppressed. In addition, it was found that the Brass orientation is often accompanied by local deformation after bending deformation, and adversely affects bendability.

180 ° when the area ratio W0 of the Cube orientation of the plate surface layer is 5 to 48% and the ratio of W0 / W4, which is the ratio of the Cube orientation area ratio W4 at the ¼ depth position, is 0.8 or more. Excellent adhesion bendability. Preferably, W0 is 10 to 40% and W0 / W4 is 0.9 or more. By setting W0 / W4 in the above range, the bending workability can be particularly improved, and both the bending workability and the material strength can be suitably achieved.
The Brass surface area ratio of the plate surface layer is preferably 20% or less, more preferably 15% or less, and further preferably 10% or less. Similarly, it is preferable to set the Brass azimuth area ratio within the above range from the viewpoint of achieving both high bending workability and material strength.

The crystal orientation display method in the present specification takes a rectangular coordinate system in which the rolling direction (RD) of the material is the X axis, the sheet width direction (TD) is the Y axis, and the rolling normal direction (ND) is the Z axis. Using the index (hkl) of the crystal plane in which each region is perpendicular to the Z axis (parallel to the rolling surface) and the index [uvw] of the crystal direction parallel to the X axis, (hkl) [uvw] Shown in shape. For the equivalent orientations under the cubic symmetry of the copper alloy, such as (1 3 2) [6 -4 3] and (2 3 1) [3 -4 6], The parenthesis is used to indicate {hkl} <uvw>.
The Cube orientation is a state in which the (100) plane faces the rolling surface normal direction (ND) and the (100) plane faces the rolling direction (RD), and an index of {0 0 1} <1 0 0> Indicated by
The Brass orientation is a state in which the (110) plane faces the rolling surface normal direction (ND) and the (112) plane faces the rolling direction (RD), and an index of {1 1 0} <1 1 2> Indicated by

The EBSD method is used for the analysis of the crystal orientation in the present invention. EBSD is an abbreviation for Electron Back Scatter Diffraction (Electron Backscatter Diffraction). Reflected Electron Kikuchi Line Diffraction (Kikuchi pattern) generated when a sample is irradiated with an electron beam in a Scanning Electron Microscope (SEM). This is the crystal orientation analysis technology used. In the present invention, a 500 μm square sample area containing 200 or more crystal grains is scanned in steps of 0.5 μm and the orientation is analyzed.
The area ratio of the Cube azimuth and the Brass azimuth is calculated by dividing the area of the region whose deviation angle from each ideal azimuth (the Cube azimuth or the Brass azimuth) is within 10 ° by the measurement area.
Regarding the deviation angle from the ideal orientation, the rotation angle was calculated around the common rotation axis, and was taken as the deviation angle. FIG. 1 shows an example of an orientation whose deviation angle from the Cube orientation is within 10 °. Here, although the azimuth | direction within 10 degrees is shown regarding the rotation axis of (100) and (110) and (111), the rotation angle with Cube azimuth | direction was calculated about all the rotation axes. The rotation axis that can be expressed at the smallest angle is adopted. The deviation angle is calculated for all measurement points, and the first decimal place is an effective number, and the area of the crystal grains having an orientation within 10 ° from each of the Cube orientation and the Brass orientation is divided by the total measurement area. And the area ratio.
The information obtained in the azimuth analysis by EBSD includes azimuth information up to a depth of several tens of nanometers at which the electron beam penetrates into the sample. It was described as an area ratio. The orientation distribution was measured from the plate surface.

In the EBSD measurement, in order to obtain a clear Kikuchi line diffraction image, it is preferable to perform the measurement after mirror polishing the surface of the substrate using colloidal silica abrasive grains after mechanical polishing.
In the EBSD measurement at the plate thickness 1/4 position, the surface layer portion up to the 1/4 position was dissolved by electrolytic polishing, and then the surface was mirror-polished and measured in the same manner as in the case of the above plate surface layer.

  Here, the characteristics of the EBSD measurement will be described as contrast with the X-ray diffraction measurement. First, the first point is a crystal orientation that cannot be measured by X-ray diffraction measurement, and these are the S orientation and the BR orientation. In other words, by using EBSD, information on the S orientation and the BR orientation is obtained for the first time, and the relationship between the alloy structure and the action specified thereby becomes clear. Second, X-ray diffraction measures the amount of crystal orientation included in about ± 0.5 ° of ND // {hkl}. On the other hand, EBSD measures the amount of crystal orientation included within ± 10 ° from the orientation. Therefore, according to the EBSD measurement, information on an extremely wide range of alloy structure is comprehensively obtained, and it becomes clear that it is difficult to specify the entire alloy material by X-ray diffraction. As described above, contents and properties of information obtained by EBSD measurement and X-ray diffraction measurement are different. In addition, unless otherwise indicated in this specification, the result of EBSD was performed with respect to the ND direction of a copper alloy board | plate material.

(Alloy composition, etc.)
Copper-based materials suitably used as connector materials are classified into pure copper-based and high-strength copper-based materials, and high-strength copper-based materials are further classified into a solid solution type and a precipitation type. In this invention, the precipitation type copper alloy which has the electroconductivity, mechanical strength, and heat resistance which are requested | required of a connector is preferable. In particular, in order to achieve both high strength and high conductivity, Cu—Ni—Si, Cu—Ni—Co—Si, and Cu—Co—Si alloys are preferable.

・ Ni, Co, Si
In the present invention, nickel (Ni), cobalt (Co), and silicon (Si), which are the first additive element group to be added to copper (Cu), are controlled by controlling the addition amount of Ni—Si, Co. It is possible to improve the strength of the copper alloy by precipitating a compound of -Si and Ni-Co-Si. The amount of addition is one or two of Ni and Co in total, preferably 0.5 to 5.0 mass%, more preferably 0.6 to 4.5 mass%, more preferably 0.8 to 4.0 mass%. As content of Si, Preferably it is 0.1-1.5 mass%, More preferably, it is 0.2-1.2 mass%. If the amount of these elements is too large, the electrical conductivity tends to decrease, and if the amount is too small, the strength tends to be insufficient. In addition, when it is desired to increase the electrical conductivity, it is preferable to add Co. In this case, the amount of Co added is 0.4 to 1.5 mass%, more preferably 0.6 to 2.0 mass%. It is. In addition, since Co is a rare element and increases the solution temperature by addition, it is preferable not to add it when there is no need to significantly increase the conductivity depending on the application.

-Average particle diameter An average crystal grain diameter shall be 12-100 micrometers. If it is too small, the stress relaxation resistance is inferior, and if it is too large, the bending workability is inferior. Further, in order to control the crystal grain size to a range smaller than 12 μm, it is necessary to control the ultimate temperature in the final solution heat treatment as will be described later. May become insufficient and may be accompanied by a decrease in age precipitation hardening. From this viewpoint, the average crystal grain size is 12 μm or more. More preferably, it is 22-80 micrometers.
In addition, the average crystal grain diameter in the present invention is a value measured according to JIS H 0501 (cutting method).

-Other elements The copper alloy sheet material of the present invention is selected from the group consisting of Sn, Zn, Ag, Mn, B, P, Mg, Cr, Fe, Ti, Zr and Hf together with the first additive element group. You may contain at least 1 sort. The average crystal grain size in this composition and its preferred range are also the same as above.
At least one selected from the group consisting of Sn, Zn, Ag, Mn, B, P, Mg, Cr, Fe, Ti, Zr and Hf in order to fully exhibit the additive effect and not lower the electrical conductivity The total content of additive elements is 0.005 to 2.0 mass%, preferably 0.1 to 1.5 mass%, and more preferably 0.7 to 1.2 mass%. If the total amount of these additive elements is too large, the conductivity is lowered. If the amount is too small, the effect of adding these elements is hardly exhibited.

  The effect of adding each element is shown below. When Mg, Sn, and Zn are added to Cu—Ni—Si, Cu—Ni—Co—Si, and Cu—Co—Si copper alloys, the stress relaxation resistance is improved. The stress relaxation resistance is further improved by a synergistic effect when added together than when they are added. In addition, there is an effect of remarkably improving solder embrittlement. A preferable range of the total of Mg, Sn, and Zn is 0.12 to 1.0 mass% in total.

  When Mn, Ag, B, and P are added, the hot workability is improved and the strength is improved. A preferable range of the total of Mn, Ag, B, and P is 0.12 to 0.5 mass% in total.

  Cr, Fe, Ti, Zr, and Hf are finely precipitated as a single additive or a compound with Ni, Co, or Si as main additive elements, and contribute to precipitation hardening. Moreover, it precipitates with the magnitude | size of 50-500 nm as a compound, and there exists an effect which makes a crystal grain size fine by suppressing grain growth, and makes bending workability favorable. A preferable total range of Cr, Fe, Ti, Zr, and Hf is 0.12 to 0.5 mass% in total.

(Manufacturing method etc.)
Next, a method for controlling the area ratio of the Cube orientation and the Brass orientation in the vicinity of the plate thickness surface layer and the 1/4 thickness position will be described. Here, a plate material (strip material) of a precipitation-type copper alloy will be described as an example, but the present invention can be applied to a solid solution alloy material, a dilute alloy material, and a pure copper material.
In general, a precipitation-type copper alloy is obtained by thinning a homogenized heat-treated ingot at each step of hot rolling and cold rolling, and performing a final solution heat treatment in a temperature range of 700 to 1020 ° C. to re-solidify solute atoms. Then, it is manufactured so as to satisfy the required strength by aging precipitation heat treatment and finish cold rolling. The conditions for the aging precipitation heat treatment and the finish cold rolling are adjusted according to characteristics such as desired strength and conductivity. The texture is roughly determined by recrystallization occurring during the final solution heat treatment in this series of steps, and finally determined by the orientation rotation occurring during finish rolling.
The hot rolling is for utilizing low deformation resistance and high deformability at high temperatures, and has a great advantage of reducing energy required for processing as compared with cold. On the other hand, in precipitation hardening type alloys, precipitation may occur depending on the hot rolling temperature. However, precipitates at this high temperature are generally coarse, so they are not completely dissolved in the final solution heat treatment. As a result, precipitation hardening in the aging precipitation heat treatment may be insufficient. Alternatively, if the final solution heat treatment is heated to a high temperature and the precipitates in hot rolling are completely dissolved, the crystal grains become coarse, and this time the bending workability may deteriorate. For this reason, in order to suppress precipitation as much as possible during hot rolling, the number of passes is reduced by increasing the one-pass processing rate as much as possible, and no holding is taken between passes. It is a design guideline for a general hot rolling process that rolling is finished in a short time at a high temperature, and after hot rolling, it is rapidly cooled by a method such as water cooling to keep it close to a supersaturated solid solution.

In the general hot rolling and a series of manufacturing methods as described above, the area ratios of the Cube orientation and the Brass orientation in the vicinity of the thickness surface layer and the 1/4 thickness position are stably controlled within the range defined by the present invention. This is difficult to achieve and has been confirmed to be achieved by the manufacturing method shown below.
・ Process conditions I
First, the hot rolling is preferably one in which the one-pass processing rate is 30% or less, and the rolling direction for the material is alternately changed for each pass by reverse rolling. This is because by changing the rolling direction alternately in each rolling for the surface layer to which a large shear stress is applied, the shear strain is canceled and the rotation of the crystal on the plate surface layer is controlled, and the compressive stress is applied. This is considered to be due to the effect of suppressing the formation of a different structure from the inside. Under the above conditions, the fluctuation of the structure in the thickness direction can be reduced. Also, the holding time between passes is 20 to 100 seconds (preferably 20 to 50 seconds, more preferably 20 to 30 seconds), and the temperature drop between passes is 5 to 100 ° C. Is good. By controlling the time and temperature between the passes, static recrystallization and recovery occur in the material, and the variation of the structure in the thickness direction can be reduced. The temperature between passes is measured with a radiation thermometer or a contact thermocouple thermometer. In controlling the pass and the temperature of the pass, it is heated by a burner or the like, and cooled by air cooling or water cooling.
Note that when the pass and the holding time of the pass exceed 100 seconds, the material temperature is excessively lowered, so that surface cracks and edge cracks occur during rolling, which is not preferable.
・ Process condition II
Second, cold rolling performed after hot rolling and subsequent scale removal is preferably 90% to 99% and lubricated rolling. If it is less than 90%, the surface layer formed by hot rolling and the internal structure may be affected. If it exceeds 99%, edge cracks may occur.

・ Process condition III
Third, before the final solution heat treatment, it is preferable to introduce an annealing heat treatment (intermediate heat treatment) and then cold rolling with a low processing rate, and then perform the final solution heat treatment. This introduced annealing heat treatment is performed at a temperature of 300 to 700 ° C. for 10 seconds to 5 hours, and the subsequent cold rolling has a working rate of 5 to 50%.
・ Process condition IV
Fourth, the final solution heat treatment is preferably performed at a relatively high temperature such that the average crystal grain size is 12 to 100 μm. This is because the precipitate generated between the hot rolling passes and the precipitate generated in the annealing heat treatment before the final solution heat treatment are dissolved. In the above general process, when the temperature of the final solution heat treatment is increased, the bending workability is lowered due to the coarsening of the crystal grains, but when the Cube orientation area ratio is increased as in the present invention, the crystal orientation is increased. The deterioration of bendability is slight due to the effect. The temperature for controlling the average crystal grain size to 12 to 100 μm varies depending on the alloy components, but a temperature of 800 ° C. to 1000 ° C. is preferable.

  Among the above four, the production methods shown in the first (condition I), the third (condition III) and the fourth (condition IV) are different from the conventional production methods for precipitation type copper alloys. It is extremely important for the present invention. A more preferable state can be obtained by using the second production method in combination.

Previous literature on hot rolling in the Cu—Ni—Si system describes precipitation during hot rolling as a phenomenon that should be suppressed as much as possible. Therefore, as a method for suppressing the precipitation of Ni and Si that causes a decrease in bending workability and strength, and the coarsening of the precipitate, for example, in paragraph [0025] of Japanese Patent No. 4209749, a method of shortening the hot rolling time Is disclosed. Further, for example, in Japanese Patent No. 4444143, a twin roll casting method is disclosed as a method in which hot rolling itself is not performed.
In order to achieve the difficult task of reducing the structural difference in the sheet thickness direction, the novel manufacturing method in the present invention takes a long holding time between passes as in process condition I, and on the other hand, as a countermeasure against precipitation that occurs during that time. The high temperature is positively adopted as in the process condition IV.

By satisfy | filling the said content, the characteristic requested | required of the copper alloy board | plate material for connectors, for example can be satisfied. In one preferred embodiment of the copper alloy sheet according to the present invention, the 0.2% proof stress is 500 MPa or more, and the conductivity is 30% IACS or more. Particularly preferably, 0.2% proof stress is 700 MPa or more, bending workability is possible without cracking in a 180 ° contact bending test with a test piece width of 1 mm, conductivity is 35% IACS or more, stress relaxation Regarding the characteristics, it is a copper alloy sheet material having good characteristics of 30% or less by a measuring method that is held at a temperature of 150 ° C. for 1000 hours, which will be described later, and it is one advantage of the present invention that such characteristics can be realized. . In the present invention, the 0.2% yield strength is a value based on JIS Z 2241. Moreover, said% IACS represents the electrical conductivity when the resistivity 1.7241 × 10 ⁻⁸ Ωm of universal standard annealed copper (International Annealed Copper Standard) is 100% IACS.

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

Example 1
As shown in the composition of the column of alloy components in Table 1-1 and Table 1-2, an alloy containing Ni, Co, Si and the balance consisting of Cu and inevitable impurities is melted in a high frequency melting furnace, and this is cast. As a result, an ingot was obtained. With this state as the providing material, the test materials of the copper alloy sheet materials of Invention Examples 1-1 to 1-12 and Comparative Examples 1-1 to 1-8 were produced in any of the following steps A to G. . Table 1-1 and Table 1-2 show which step A to G was used. The final thickness of the alloy plate was 150 μm unless otherwise specified.
In addition, although not shown in A to G, when a prototype was produced under conditions where the pass and the holding time of the pass exceeded 100 seconds, the material temperature was too low, and surface cracks and edge cracks occurred during rolling. Prototype was stopped.

(Process A)
After a homogenization heat treatment at a temperature of 900 to 1020 ° C. for 3 minutes to 10 hours, after hot working, it was cooled with water and chamfered to remove oxide scale. In the hot rolling, reverse rolling with a 1-pass processing rate of 10 to 30% was performed for a total of 4 to 12 passes, and the holding time between passes was set to 20 to 100 seconds. Thereafter, cold rolling at a processing rate of 90 to 99% was performed, heat treatment was performed at a temperature of 300 to 700 ° C. for 10 seconds to 5 hours, and cold rolling at a processing rate of 5 to 50% was performed. Thereafter, a solution heat treatment is performed at a temperature of 800 ° C. or higher for 5 seconds or more, an aging precipitation heat treatment is performed at a temperature of 350 to 600 ° C. for 5 minutes to 20 hours, a finish rolling of 5 to 40% is performed, and 300 Temper annealing was performed at a temperature of ˜700 ° C. for 10 seconds to 2 hours.

(Process B)
After a homogenization heat treatment at a temperature of 900 to 1020 ° C. for 3 minutes to 10 hours, after hot working, it was cooled with water and chamfered to remove oxide scale. In the hot rolling, reverse rolling with a 1-pass processing rate of 10 to 30% was performed for a total of 4 to 12 passes, and the holding time between passes was set to 20 to 100 seconds. Thereafter, cold rolling at a processing rate of 80 to 89% was performed, heat treatment was performed at a temperature of 300 to 700 ° C. for 10 seconds to 5 hours, and cold rolling at a processing rate of 5 to 50% was performed. Thereafter, a solution heat treatment is performed at a temperature of 800 ° C. or higher for 5 seconds or more, an aging precipitation heat treatment is performed at a temperature of 350 to 600 ° C. for 5 minutes to 20 hours, a finish rolling of 5 to 40% is performed, and 300 Temper annealing was performed at a temperature of ˜700 ° C. for 10 seconds to 2 hours.

(Process C)
After a homogenization heat treatment at a temperature of 900 to 1020 ° C. for 3 minutes to 10 hours, after hot working, it was cooled with water and chamfered to remove oxide scale. In the hot rolling, reverse rolling with a 1-pass processing rate of 10 to 30% was performed for a total of 4 to 12 passes, and the holding time between passes was set to 20 to 100 seconds. Thereafter, cold rolling at a processing rate of 90 to 99% was performed, heat treatment was performed at a temperature of 300 to 700 ° C. for 10 seconds to 5 hours, and cold rolling at a processing rate of 5 to 50% was performed. Thereafter, a solution heat treatment is performed at a temperature of 800 ° C. or higher for 5 seconds or more, an aging precipitation heat treatment is performed at a temperature of 350 to 600 ° C. for 5 minutes to 20 hours, a finish rolling of 40 to 50% is performed, and 300 Temper annealing was performed at a temperature of ˜700 ° C. for 10 seconds to 2 hours.

(Process D)
After a homogenization heat treatment at a temperature of 900 to 1020 ° C. for 3 minutes to 10 hours, after hot working, it was cooled with water and chamfered to remove oxide scale. In the hot rolling, a total of 2 to 8 passes of tandem unidirectional rolling with a one-pass working rate exceeding 30% was performed, and the holding time between passes was set to less than 20 seconds. Thereafter, cold rolling at a processing rate of 80 to 89% was performed, heat treatment was performed at a temperature of 300 to 700 ° C. for 10 seconds to 5 hours, and cold rolling at a processing rate of 5 to 50% was performed. Thereafter, a solution heat treatment is performed at a temperature of 800 ° C. or higher for 5 seconds or more, an aging precipitation heat treatment is performed at a temperature of 350 to 600 ° C. for 5 minutes to 20 hours, a finish rolling of 5 to 40% is performed, and 300 Temper annealing was performed at a temperature of ˜700 ° C. for 10 seconds to 2 hours.

(Process E)
After a homogenization heat treatment at a temperature of 900 to 1020 ° C. for 3 minutes to 10 hours, after hot working, it was cooled with water and chamfered to remove oxide scale. In the hot rolling, a total of 2 to 8 passes of tandem unidirectional rolling with a one-pass working rate exceeding 30% was performed, and the holding time between passes was set to less than 20 seconds. Thereafter, cold rolling at a working rate of 80 to 89% is performed, solution heat treatment is performed at a temperature of 800 ° C. or higher for 5 seconds or more, and aging precipitation heat treatment is performed at a temperature of 350 to 600 ° C. for 5 minutes to 20 hours. Then, finish rolling of 5 to 40% was performed, and temper annealing was performed at a temperature of 300 to 700 ° C for 10 seconds to 2 hours.

(Process F)
After a homogenization heat treatment at a temperature of 900 to 1020 ° C. for 3 minutes to 10 hours, after hot working, it was cooled with water and chamfered to remove oxide scale. In the hot rolling, reverse rolling with a 1-pass processing rate of 10 to 30% was performed for a total of 4 to 12 passes, and the holding time between passes was set to 20 to 100 seconds. Thereafter, cold rolling at a processing rate of 90 to 99% was performed, heat treatment was performed at a temperature of 300 to 700 ° C. for 10 seconds to 5 hours, and cold rolling at a processing rate of 5 to 50% was performed. Solution heat treatment is performed at a temperature of 650 to 750 ° C. for 2 hours, aging precipitation heat treatment is performed at a temperature of 350 to 600 ° C. for 5 minutes to 20 hours, finish rolling is performed at 5 to 40%, and 300 to 700 ° C. Refining annealing was performed at a temperature of 10 seconds to 2 hours.

(Process G)
After a homogenization heat treatment at a temperature of 900 to 1020 ° C. for 3 minutes to 10 hours, after hot working, it was cooled with water and chamfered to remove oxide scale. In the hot rolling, reverse rolling with a 1-pass processing rate of 10 to 30% was performed for a total of 4 to 12 passes, and the holding time between passes was set to 20 to 100 seconds. Thereafter, cold rolling at a processing rate of 80 to 89% was performed, heat treatment was performed at a temperature of 300 to 700 ° C. for 10 seconds to 5 hours, and cold rolling at a processing rate of 5 to 50% was performed. A solution heat treatment is performed at a temperature of 730 to 770 ° C. for 5 to 30 seconds, an aging precipitation heat treatment is performed at a temperature of 350 to 600 ° C. for 5 minutes to 20 hours, a finish rolling of 5 to 40% is performed, and 300 to Temper annealing was performed at a temperature of 700 ° C. for 10 seconds to 2 hours.

(Process H)
The same conditions as in Step A were adopted except that the intermediate heat treatment during the cold rolling (at a temperature of 300 to 700 ° C. for 10 seconds to 5 hours) was not performed.

  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.

Each characteristic was measured and evaluated for this specimen as follows. Here, the thickness of the test material was 0.15 mm. The results are shown in Table 1-1 and Table 1-2.
a. Cube orientation area ratio [W0, W0 / W4]:
By the EBSD method, measurement was performed in a measurement region of about 500 μm square under the condition that the scan step was 0.5 μm. The measurement area was adjusted based on the inclusion of 200 or more crystal grains. As described above, with respect to the deviation angle from the ideal orientation, the rotation angle is calculated around the common rotation axis, and is set as the deviation angle. The rotation angle with the Cube orientation was calculated for all rotation axes. The rotation axis that can be expressed at the smallest angle is adopted. The deviation angle is calculated for all measurement points, the first decimal place is an effective number, the area of crystal grains with an orientation within 10 ° from the Cube orientation is divided by the total measurement area, and the area ratio is calculated. did. W0 is a measurement result from the plate surface, W4 is a measurement result at a 1/4 depth position in the plate thickness direction, and W0 / W4 is a ratio thereof.

b. Area ratio of Brass orientation [B0]:
It measured from the plate | board surface similarly to the area ratio of the above-mentioned Cube azimuth | direction.
c. Average crystal grain size [GS]:
Measured based on JIS H 0501 (cutting method). Measurements were taken on a cross section parallel to the rolling direction and a cross section perpendicular to the rolling direction, and the average of the two was taken. The metal structure was observed by chemically edging the mirror-polished material surface and observing with an optical microscope.

d. 180 ° adhesion bending workability [bending workability]:
GW (Good Way) obtained by punching with a press perpendicularly to the rolling direction to a width of 1 mm and a length of 25 mm, and W bent so that the axis of bending is perpendicular to the rolling direction is W to be parallel to the rolling direction. The bent one was designated as BW (Bad Way). Bending was performed according to JIS Z 2248. Preliminary bending was performed using a 0.4 mm R 90 ° bending mold, and then contact bending was performed using a compression tester. The presence or absence of cracks on the outside of the bent part was observed by visual observation with a 50 × optical microscope, and the presence or absence of cracks was investigated. Bending parts were evaluated as “A” when there were no cracks and slight wrinkles, “B” when there were no cracks but large wrinkles, and “C” when there were cracks.

e. 0.2% yield strength [YS]:
Three test pieces of JIS Z2201-13B cut out from the rolling parallel direction were measured according to JIS Z2241, and the average value was shown. Here, the YS value of 550 MPa or more was assumed to be excellent in strength.
f: Conductivity [EC]:
The specific resistance was measured by a four-terminal method in a constant temperature bath maintained at 20 ° C. (± 0.5 ° C.) to calculate the conductivity. In addition, the distance between terminals was 100 mm. Here, the one having an EC value of 35% IACS or more is considered to have excellent conductivity.
g. Stress relaxation rate [SR]:
In accordance with JCBA T309: 2001 (corresponding to the former Japan Electronic Materials Industry Association Standard EMAS-3003), which is a provisional standard of the Japan Copper and Brass Association, as shown below, measurement was performed under conditions after holding at 150 ° C. for 1000 hours. . An initial stress of 80% of the proof stress was applied by the cantilever method. Here, the SR value of 30% or less was assumed to be excellent in stress relaxation resistance.

FIG. 2 is an explanatory view of a stress relaxation characteristic test method, in which (a) shows a state before heat treatment and (b) shows a state after heat treatment. As shown in FIG. 2A, the position of the test piece 1 when an initial stress of 80% of the proof stress is applied to the test piece 1 held in a cantilever manner on the test stand 4 is a distance of δ ₀ from the reference. is there. This is held in a thermostatic bath at 150 ° C. for 1000 hours (heat treatment in the state of the test piece 1), and the position of the test piece 2 after removing the load is determined from the reference H _t as shown in FIG. Is the distance. 3 is a test piece when no stress is applied, and its position is a distance H ₁ from the reference. From this relationship, the stress relaxation rate (%) was calculated as (H _t −H ₁ ) / (δ ₀ −H ₁ ) × 100. In the equation, δ ₀ is the distance from the reference to the test piece 1, H ₁ is the distance from the reference to the test piece 3, and H _t is the distance from the reference to the test piece 2.

As shown in Table 1-2, the sample of the comparative example resulted in inferior properties.
That is, in Comparative Example 1-1, since the total amount of Ni and Co was small, the density of precipitates contributing to precipitation hardening was lowered and the strength was inferior. Further, Si that does not form a compound with Ni or Co was excessively dissolved in the metal structure, resulting in poor conductivity. Moreover, the stress relaxation resistance was also inferior. Since Comparative Example 1-2 had a large total amount of Ni and Co, the conductivity was inferior. Comparative Example 1-3 was inferior in strength due to a small amount of Si. Comparative Example 1-4 was inferior in electrical conductivity because of a large amount of Si.
Comparative Example 1-5 had a low W0 / W4 and was inferior in 180 ° contact bending workability. In Comparative Example 1-6, W0 / W4 and W0 were low, and the 180 ° contact bending workability was inferior. In Comparative Example 1-7, W0 and the average crystal grain size were high, and the 180 ° contact bending workability was inferior. In Comparative Example 1-8, the average crystal grain size was small and the stress relaxation resistance was inferior.
On the other hand, as shown in Table 1-1, Examples 1-1 to 1-12 of the present invention were excellent in any of 180 ° contact bending workability, yield strength, electrical conductivity, and stress relaxation characteristics. In particular, Examples 1-1, 1-2, 1-4, 1-6, 1-7, 1-8, 1-9, 1-11, 1- 1 of the present invention having a Brass layer area ratio of 20% or less on the surface layer. In No. 12, at least one of GW and BW showed very excellent bending workability with no cracks and slight wrinkles.

Example 2
In the composition shown in the column of alloy components in Table 2, with respect to the copper alloy consisting of Cu and inevitable impurities, the same as Example 1, Invention Examples 2-1 to 2-8 and Comparative Examples 2-1 to 2 -3 copper alloy sheet materials were produced, and each characteristic was measured and evaluated in the same manner as in Example 1. The results are shown in Table 2.

Comparative Example 3
The alloy composition of Example 1-1 of the present invention was adopted, and a copper alloy sheet was produced through process H. About this, the result of having performed evaluation similar to said each Example is as follows.

  The copper alloy sheet produced without the intermediate heat treatment as described above had a small W0 and poor 180 ° contact bending workability even when the predetermined alloy composition, hot rolling conditions and solution heat treatment conditions were adopted.

As shown in Table 2, Comparative Examples 2-1, 2-2, and 2-3 are Sn, Zn, Ag, Mn, B, P, Mg, Cr, Fe, Ti, Zr and other elements shown as other elements. The conductivity was inferior because the total amount of Hf added was too large.
On the other hand, Invention Example 2-1 to Invention Example 2-8 were excellent in all of bending workability, yield strength, conductivity, and stress relaxation characteristics.
Thus, the copper alloy plate material of the present invention has excellent characteristics suitable for a connector material.

  Subsequently, in order to clarify the difference from the copper alloy sheet material according to the present invention, the copper alloy sheet material produced under the conventional production conditions, the copper alloy sheet material is produced under the conditions, and the same characteristic items as described above are evaluated. Went. 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) ... Conditions of JP2009-007666 A metal element similar to that of Invention Example 1-1 is blended, and an alloy composed of Cu and inevitable impurities is melted in a high-frequency melting furnace. This was cast at a cooling rate of 0.1 to 100 ° C./second to obtain an ingot. This was held at 900 to 1020 ° C. for 3 minutes to 10 hours, then hot worked, then water quenched, and chamfered to remove oxide scale. In the subsequent steps, the copper alloy c01 was manufactured by performing the processes of steps A-3 and B-3 described below. In addition, about the said hot working, detailed conditions are not clear from the said gazette, Temperature: 800-1020 degreeC which was general conditions at the time of this-application application: 1 pass processing rate 35-40%, each pass Holding time in between: The conditions of 3 to 7 seconds were adopted.
The manufacturing process includes one or more solution heat treatments, and here, the process is classified before and after the last solution heat treatment, and the process up to the intermediate solution is A-3 process, It was set as B-3 process in the process after intermediate solution.

Step A-3: A cold working with a cross-sectional reduction rate of 20% or more is performed, a heat treatment is performed at 350 to 750 ° C. for 5 minutes to 10 hours, a cold working with a cross-sectional reduction rate of 5 to 50% is performed, and 800 A solution heat treatment is performed at ˜1000 ° C. for 5 seconds to 30 minutes.
Step B-3: cold working with a cross-section reduction rate of 50% or less, heat treatment at 400 to 700 ° C. for 5 minutes to 10 hours, and cold working with a cross-section reduction rate of 30% or less, 200 to Temper annealing is performed at 550 ° C. for 5 seconds to 10 hours.

  The obtained specimen c01 was different from the above example in terms of manufacturing conditions in terms of hot working conditions, and did not satisfy the required characteristics for 180 ° contact bending workability.

(Comparative Example 102) ... Conditions of JP-A-2006-009137 A copper alloy having the same composition as that of Example 1-1 of the present invention was melted in a high-frequency melting furnace, and a thickness of 30 mm, a width of 100 mm, and a length were measured by a DC method. Cast into a 150 mm 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. In addition, the conditions of the hot rolling refer to paragraph [0027] of the same publication, the temperature is in the range of 900 to 1000 ° C., and the cold rolling after hot rolling is set to a processing rate of 90% or more. The processing rate for one pass and the holding time between each pass were performed under the conditions of 35 to 40% and 3 to 7 seconds, which were general conditions at the time of filing this application.
Next, the hot-rolled plate was cut at 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 (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), which was the final plastic working, was performed, and the final plate thickness was made uniform. After the final plastic working, a low temperature annealing was subsequently performed at 375 ° C. for 2 hours to produce a copper alloy sheet (sample c02).

  The obtained test body c02 was different from the above examples in terms of manufacturing conditions in terms of hot rolling conditions and the presence or absence of intermediate heat treatment, and did not satisfy the 180 ° contact bending workability.

(Comparative Example 103) ... Conditions of Japanese Patent Application Laid-Open No. 11-335756 A copper alloy having the same composition as that of Example 1-1 of the present invention is dissolved in the atmosphere under a charcoal coating in a kryptor furnace and cast into a book mold. An ingot of 50 mm × 80 mm × 200 mm was produced. The ingot was heated to 930 ° C., hot-rolled to a thickness of 15 mm, and immediately quenched in water. In order to remove the oxide scale on the surface of the hot rolled material, the surface was cut with a grinder. This was cold-rolled, then heat treated at 750 ° C. for 20 seconds, cold-rolled at 30%, and subjected to precipitation annealing at 480 ° C. for 2 hours to obtain a material with adjusted sheet thickness, which was subjected to the test (c02 ). In the hot rolling, the processing rate of one pass and the holding time between the passes are the one-pass processing rate of 35 to 40%, which was a general condition at the time of filing of the present application, and the holding time between the passes: 3 to 3. The condition of 7 seconds was adopted.

  The obtained test body c02 was different from the above examples in terms of manufacturing conditions in terms of hot rolling conditions and the presence or absence of intermediate heat treatment, and did not satisfy the 180 ° contact bending workability.

(Comparative Example 104) ... Conditions of Japanese Patent Application Laid-Open No. 2006-283059 The copper alloy having the composition of Example 1-1 of the present invention was melted under charcoal coating in the atmosphere in an electric furnace, and castability was judged. . The molten ingot was hot-rolled to a thickness of 15 mm. Subsequently, the hot rolled material is subjected to cold rolling and heat treatment (cold rolling 1 → solution annealing, cold rolling 2 → aging treatment → cold rolling 3 → short annealing) to a predetermined thickness. A copper alloy sheet (c04) was produced. In addition, the solution treatment was performed under the condition of referring to paragraph [0027] of the same publication and maintaining the body temperature at 800 to 950 ° C. for 30 seconds or less. There is no detailed disclosure about hot rolling, which was a general condition at the time of filing this application, adopting the conditions of 1-pass processing rate of 35-40% and holding time between each pass of 3-7 seconds It was.

  The obtained specimen c04 differs from the above Example 1 in terms of manufacturing conditions in terms of hot rolling conditions and the presence or absence of intermediate heat treatment, and did not satisfy the 180 ° contact bending workability.

(Comparative Example 105) ... Conditions of Japanese Patent Application Laid-Open No. 2006-152392 The alloy having the composition of Invention Example 1-1 was melted under a charcoal coating in the atmosphere in a kryptor furnace and cast into a cast iron book mold. Thus, an ingot having a thickness of 50 mm, a width of 75 mm, and a length of 180 mm was obtained. Then, after chamfering the surface of the ingot, it was hot-rolled at a temperature of 950 ° C. until the thickness became 15 mm, and rapidly cooled into water from a temperature of 750 ° C. or higher. Next, after removing the oxide scale, cold rolling was performed to obtain a plate having a predetermined thickness. In hot rolling, the processing rate of one pass and the holding time between each pass are 35 to 40% of the one-pass processing rate, which was a general condition at the time of filing the present application, and the holding time between each pass is 3%. The condition of ˜7 seconds was adopted.

  Subsequently, after using a salt bath furnace and performing a solution treatment by heating at a temperature for 20 seconds, the solution was rapidly cooled in water, and then cold-rolled sheets having various thicknesses were obtained by finish cold rolling in the latter half. At this time, as shown below, the cold-rolled sheet (c05) was obtained by variously changing the cold rolling processing rate (%). As shown below, these cold-rolled sheets were subjected to aging treatment at various temperatures (° C.) and times (hr).

Cold working rate: 95%
Solution treatment temperature: 900 ° C
Artificial age hardening temperature x time: 450 ° C x 4 hours Thickness: 0.6mm

  The obtained specimen c05 differs from the above Example 1 in terms of manufacturing conditions in terms of hot rolling conditions and the presence or absence of intermediate heat treatment, and did not satisfy the 180 ° contact bending workability.

(Comparative Example 106) ... Conditions of JP-A-2008-223136 The copper alloy shown in Example 1 was melted and cast using a vertical continuous casting machine. A sample with a thickness of 50 mm was cut out from the obtained slab (thickness 180 mm), heated to 950 ° C., extracted, and hot rolling was started. At that time, the pass schedule was set so that the rolling rate in the temperature range of 950 ° C. to 700 ° C. was 60% or more and the rolling was performed even in the temperature range of less than 700 ° C. The final pass temperature of hot rolling is between 600 ° C and 400 ° C. The total hot rolling rate from the slab is about 90%. After hot rolling, the surface oxide layer was removed (faced) by mechanical polishing. In the hot rolling, the holding time between the passes was set to 3 to 7 seconds, which was a common condition at the time of filing the present application.

  Subsequently, after performing cold rolling, it used for the solution treatment. The temperature change during the solution treatment was monitored by a thermocouple attached to the sample surface, and the temperature raising time from 100 ° C. to 700 ° C. in the temperature raising process was determined. The ultimate temperature is adjusted within the range of 700 to 850 ° C. according to the alloy composition so that the average crystal grain size after solution treatment (the twin boundary is not regarded as a grain boundary) is 10 to 60 μm. The holding time in the temperature range of 850 ° C. was adjusted in the range of 10 sec to 10 min. Subsequently, the plate material after the solution treatment was subjected to intermediate cold rolling at a rolling rate and then subjected to an aging treatment. The aging treatment temperature was adjusted to a material temperature of 450 ° C., and the aging time was adjusted to a time when the hardness peaked at 450 ° C. according to the alloy composition. The optimum solution treatment conditions and aging treatment time according to such an alloy composition have been grasped by preliminary experiments. Next, finish cold rolling was performed at a rolling rate. About what performed finish cold rolling, the low temperature annealing which puts it in a 400 degreeC furnace for 5 minutes after that was given after that. In this way, a test material was obtained. If necessary, chamfering was performed in the middle, and the thickness of the specimen was adjusted to 0.2 mm. The main production conditions are described below.

[Conditions of Comparative Example 1 of JP2008-223136A]
Hot rolling ratio at less than 700 ° C to 400 ° C: 17% (1 pass)
Before solution treatment Cold rolling rate: 90%
Intermediate cold rolling Cold rolling rate: 20%
Finish cold rolling Cold rolling rate: 30%
Temperature rising time from 100 ° C to 700 ° C: 10 seconds

  The obtained specimen c05 differs from the above Example 1 in terms of manufacturing conditions in terms of hot rolling conditions and the presence or absence of intermediate heat treatment, and did not satisfy the 180 ° contact bending workability.

DESCRIPTION OF SYMBOLS 1 Test piece when initial stress was applied 2 Test piece after removing load 3 Test piece when stress was not applied 4 Test stand

Claims (5)

  A plate material composed of a copper alloy composition containing at least one of Ni and Co in a total amount of 0.5 to 5.0 mass%, Si of 0.1 to 1.2 mass%, and the balance of Cu and inevitable impurities, In the crystal orientation analysis in the backscatter diffraction measurement, the area ratio of the Cube orientation {0 0 1} <1 0 0> of the material surface layer is W0, and the Cube orientation area ratio at the 1/4 position of the whole at the depth position of the material. W0 / W4 ratio is 0.8 or more and 1.5 or less, W0 is 5 to 48%, and average crystal grain size is 12 to 100 μm, where W4 is W4. Copper alloy sheet with excellent heat resistance and stress relaxation resistance.   Furthermore, 0.005-2.0 mass% in total containing at least 1 sort (s) chosen from the group which consists of Sn, Zn, Ag, Mn, B, P, Mg, Cr, Fe, Ti, Zr, and Hf is contained. The copper alloy sheet material described in 1.   The copper alloy sheet material according to claim 1 or 2, wherein the area ratio of the Brass orientation {1 1 0} <1 1 2> is 20% or less. The connector which consists of a copper alloy board | plate material of any one of Claims 1-3. It is a manufacturing method of the copper alloy sheet material according to any one of claims 1 to 3,
A copper alloy ingot having the composition according to claim 1 or 2 is subjected to at least the following steps I, II, III , IV , and V in that order, and then finished at a processing rate of 5 to 40%. A method for producing a copper alloy sheet comprising rolling.
[Step I: Hot rolling step with a pass processing rate of 30% or less and a holding time between passes of 20 to 30 seconds]
[Step II: Cold rolling step with a processing rate of 80% to 99%]
[Step III: An intermediate heat treatment step at a temperature of 300 to 700 ° C. for 10 seconds to 5 hours and a cold rolling step performed thereafter at a processing rate of 5 to 50%]
[Step IV: Solution heat treatment step performed at 800 to 1000 ° C.]
[Step V: Aging precipitation heat treatment step at 350 to 600 ° C. for 5 minutes to 20 hours and finish cold rolling step with a processing rate of 5 to 40%]

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