JP5261582B2 - Copper alloy sheet and manufacturing method thereof - Google Patents

Abstract

{Problems} To provide a copper alloy sheet material and a method of producing the same, which sheet material is excellent in a bending property, and has an excellent mechanical strength, and which is suitable for lead frames, connectors, terminal materials, and the like in electrical/electronic equipments, for connectors, for example, to be mounted on automotive vehicles, and for terminal materials, relays, switches, and the like. {Means to solve} A copper alloy sheet material, containing Ti in an amount of 1.0 to 5.0 mass%, with the balance being copper and unavoidable impurities, wherein an area ratio of Cube orientation {0 0 1} <1 0 0> is 5 to 50%, in crystal orientation analysis by an EBSD analysis in the sheet thickness of the sheet material; and a method of producing the same.

Description

  TECHNICAL FIELD The present invention relates to a copper alloy plate material and a method for manufacturing the same, and more particularly to a copper alloy plate material applied to in-vehicle components and components for electric and electronic devices, such as lead frames, connectors, terminal materials, relays, switches, sockets, motors and the like. And a manufacturing method thereof.

  Characteristic items required for copper alloy sheets used in automotive parts and lead frames, connectors, terminal materials, relays, switches, sockets, etc. for electric components, electrical conductivity, yield strength, Has tensile strength, bending workability, and stress relaxation resistance. In recent years, the required characteristics have been increased with the downsizing, weight reduction, high functionality, high density mounting, and high usage environment of electric / electronic devices.

  Conventionally, as an electric / electronic device material, copper alloy materials such as phosphor bronze, red brass, brass and the like are widely used in addition to iron-based materials. These copper 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 high strength is obtained by adding a high cold work rate, so that bending workability and stress relaxation resistance are insufficient.

  An alternative strengthening method is precipitation strengthening in which a fine second phase is precipitated in the material. This strengthening method has a merit 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 devices and automobiles, the copper alloy sheet used has been bent to a higher strength copper alloy material with a smaller radius. Therefore, there is a strong demand for a copper alloy sheet material excellent in bending workability. In the conventional Cu-Ti system, in order to obtain high strength, the rolling process rate was increased and large work hardening was obtained. However, as described above, this method deteriorates bending workability, and high strength and good. It was not possible to achieve both 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 disclosures have been made on Cu—Ni—Si based copper alloys. In Patent Document 1, in a Cu—Ni—Si based copper alloy, the crystal grain size and the crystal orientation satisfying a certain condition of X-ray diffraction intensity I from {311}, {220}, {200} planes Furthermore, 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. Further, in Patent Document 3, it has been found that in a Cu—Ni—Si based copper alloy, bending workability is excellent by controlling the ratio of the Cube orientation {100} <001>.

Moreover, there is the following disclosure in the Cu—Ti based copper alloy. In Patent Document 4, the (311) plane is developed, and the press punchability is improved by satisfying I (311) / I (111) ≧ 0.5. In Patent Document 5, the amount of addition of Ti and the third element other than Ti, the temperature and rolling rate in each stage of hot rolling performed in two stages, the processing rate of cold rolling, solution treatment conditions, and aging precipitation conditions are set. By changing, it has a crystal orientation that satisfies the average crystal grain size and the X-ray diffraction intensity I {420} / I ₀ {420}> 1.0 on the plate surface of the copper alloy sheet, and has high strength and bending after notching We have proposed copper alloy sheet materials with excellent workability. In Patent Document 6, in addition to the homogenization conditions, the final pass temperature of hot rolling, the average degree of processing of each pass of hot rolling, solution treatment conditions performed in two stages, cold rolling performed after each solution treatment By changing the workability and aging conditions, a copper alloy having high strength, excellent bending workability and high dimensional stability is proposed. In Patent Document 7, an attempt is made to achieve both strength and bending workability by obtaining a recrystallized texture having a {200} crystal plane as a main orientation component.

  In addition, as one of the characteristic items required for a copper alloy sheet used for electrical / 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 copper alloy sheet material, the influence of dimensional variation on the contact contact pressure can be reduced, so that the design is facilitated.

JP 2006-009137 A JP 2008-013836 A JP 2006-283059 A JP 2006-249565 A JP 2010-126777 A JP 2007-270267 A JP 2011-26635 A

By the way, in the invention described in Patent Document 1 or Patent Document 2, the analysis of crystal orientation by X-ray diffraction from a specific surface is performed by analyzing only a part of specific surfaces in a distribution of crystal orientation having a certain spread. It is about. In the invention described in Patent Document 3, the strength and bending workability are both achieved by increasing the Cube orientation area ratio to 50% or more for the Cu—Ni—Si based alloy. Here, the control of the crystal orientation is realized by reducing the rolling rate after the solution heat treatment. In the invention described in Patent Document 4, the (311) plane is developed by cold rolling in a state where the solute atoms are completely in solid solution, and I (311) / I (111) ≧ 0.5. This improves press punchability. In the manufacturing process, orientation control is performed by cold rolling, recrystallization annealing, and subsequent processes. In Patent Document 5, bending workability after notching is improved by controlling the texture having an average crystal grain size of 5 to 25 μm and a {420} crystal plane as a main orientation component. In the production method, there are descriptions regarding hot rolling conditions, cold rolling conditions, solution heat treatment conditions, and aging precipitation conditions, but hot rolling is performed in two stages, and intermediate annealing before solution heat treatment and Solution treatment is performed without subsequent cold rolling. In Patent Document 6, the wavelength and amplitude of the titanium concentration wave (so-called modulation structure) formed in the parent phase are stabilized by precipitating the third element group as second phase particles. Furthermore, by controlling the number density of the second phase particles, both strength and bending workability are achieved, and the dimensional accuracy of press working is also increased. In the production method, the cold rolling processing rate before the final solution treatment is as high as 70 to 99%, and the heat history is defined by the present invention in both the first and last two stages of solution treatment. Is completely different. In Patent Document 7, the average grain size of recrystallized grains is controlled by solution heat treatment, and a recrystallized texture having a {200} crystal plane as a main orientation component is obtained, thereby achieving both strength and bending workability. Yes. In the process, intermediate annealing after cold rolling is performed at 450 to 600 ° C. for 1 to 20 hours, which is greatly different from the conditions of the present invention. Although bending workability is improved by increasing the diffraction intensity of I {200}, there is no description regarding bending wrinkle reduction, Young's modulus, and deflection coefficient.
On the other hand, in connection with the recent miniaturization, high functionality, high density mounting, etc. of electrical / electronic devices, copper alloy sheet materials for electrical / electronic devices have been disclosed in the inventions described in the aforementioned patent documents. There has been a demand for higher bending workability than expected bending workability and further reduction of bending wrinkles on the bent surface portion.

  Cu-Ti needs to be cast in an inert gas or in a vacuum melting furnace to prevent oxidation of Ti. Nevertheless, the ingot contains coarse crystallized products and precipitates composed of oxides. There is a possibility that dislocations and strains are introduced around these during strong processing (cold rolling) of 80% or more, and the orientation rotation may be hindered by recrystallization solution heat treatment for growing the Cube orientation. .

  In view of the problems as described above, the object of the present invention is to provide superior bending workability, excellent strength, and lead frames, connectors, terminal materials, etc. for electrical and electronic devices, such as connectors for automobiles and terminals. An object of the present invention is to provide a copper alloy sheet suitable for materials, relays, switches, and the like, and a method for manufacturing the same.

  In order to greatly improve bending workability, strength, conductivity, and stress relaxation resistance in Cu-Ti-based copper alloys, the present inventors have studied copper alloy sheet materials suitable for electric / electronic component applications. , Discovered that there is a correlation between the Cube orientation accumulation ratio and the bending workability, and after intensive studies, by controlling to a specific orientation texture in a specific copper alloy composition, these desired characteristics are remarkably improved. I found that I can do it. In addition, in the copper alloy sheet having the crystal orientation and characteristics, an additional element 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 additive element which has the function to make it discovered was discovered. Moreover, the manufacturing method which has a specific process for implement | achieving the above crystal orientations was discovered. The present invention has been made based on these findings.

That is, according to the present invention, the following means are provided.
(1) A copper alloy plate material containing 1.0 to 5.0 mass% of Ti and the balance being substantially made of copper and inevitable impurities. In the crystal orientation analysis in EBSD measurement, the Cube orientation {0 0 1} < A copper alloy sheet characterized in that the area ratio of 1 0 0> is 10 to 50%;
(2) The copper alloy sheet is heated at a temperature rising rate of 10 to 30 ° C./second and reaches 600 to 800 ° C. (except 600 ° C.) in the intermediate annealing in the cold rolling process at the time of manufacture. The copper alloy sheet material according to (1), wherein
( 3 ) The copper alloy further contains at least one selected from the group consisting of Sn, Zn, Ag, Mn, B, P, Mg, Cr, Zr, Si, Fe and Hf in a total amount of 0.005 to 1. The copper alloy sheet material according to (1) or (2) , characterized by containing 0.0 mass%,
( 4 ) The 0.2% proof stress is 850 MPa or more, the bending workability is 90 ° W, there is no crack in the bending test, and the minimum bending radius (r, mm) that can be bent with small bending wrinkles is set to the thickness (t , Mm), the copper alloy sheet according to any one of (1) to (3), wherein the value (r / t) is 1 or less,
( 5 ) The Young's modulus measured by a tensile test showing a displacement amount when a certain stress is applied to the plate material is 90 to 120 GPa, and the deflection coefficient measured by the deflection test is 80 to 110 GPa. The copper alloy sheet material according to any one of ( 4 ),
( 6 ) A method for producing a copper alloy sheet according to any one of (1) to ( 5 ), wherein 0.1 to 0.1 is applied to a copper alloy material having an alloy component composition that gives the copper alloy sheet. Casting at a cooling rate of 100 ° C./sec [Step 1], homogenizing heat treatment at 800 to 1020 ° C. for 3 minutes to 10 hours [Step 2], hot rolling at 1020 to 700 ° C. [Step 3], water cooling [Step 4] , Cold rolling with a processing rate of 80 to 99.8% [Step 6], heating at a heating rate of 10 to 30 ° C / sec, reaching 600 to 800 ° C, and then rapidly cooling at 200 ° C / sec or more [Step 7], cold rolling with a processing rate of 2 to 50% [Step 8], and intermediate solution heat treatment at 600 to 1000 ° C. for 5 seconds to 1 hour [Step 9]
A method for producing a copper alloy sheet, characterized in that, in this order,
( 7 ) After the intermediate solution heat treatment [Step 9], aging precipitation heat treatment [Step 10] at 400 to 700 ° C. for 5 minutes to 10 hours, finish cold rolling with a processing rate of 3 to 25% [Step 11] And temper annealing [Step 12] at 200 to 600 ° C. for 5 seconds to 10 hours in this order, wherein the treatment temperature of the aging precipitation heat treatment [Step 10] is the intermediate solution heat treatment [Step 9]. lower than the processing temperature of, treatment temperature of the temper annealing [step 12] is characterized by lower than the processing temperature of the intermediate solution heat treatment [step 9] (6) a copper alloy according to item Manufacturing method of plate material,
( 8 ) A copper alloy part comprising the copper alloy sheet according to any one of (1) to ( 5 ), and ( 9 ) the copper alloy according to any one of (1) to ( 5 ). Connector made of plate material.

  The copper alloy sheet material of the present invention is excellent in bending workability and exhibits excellent strength. For lead frames, connectors, terminal materials, etc. for electrical and electronic equipment, connectors and terminal materials for automobiles, relays, switches, etc. It has particularly suitable properties. Moreover, according to the manufacturing method of this invention, the said copper alloy board | plate material can be manufactured suitably.

  The copper alloy sheet material of the present invention contains 1.0 to 5.0 mass% of Ti, and the balance is composed of copper and inevitable impurities. In the crystal orientation analysis in EBSD measurement, the Cube orientation {0 0 1} < Since the area ratio of 1 0 0> is 5 to 50%, the copper alloy is excellent in strength, bending workability, electrical conductivity, and stress relaxation resistance, and suitable for use in automobiles and electrical / electronic devices. Can be provided.

  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 schematic diagram showing an example in which the deviation angle from the {001} <100> Cube orientation is within 10 °. 2A and 2B are explanatory diagrams of a stress relaxation characteristic test method. FIG. 2A shows a state before heat treatment, and FIG. 2B shows a state after heat treatment. FIG. 3 is an explanatory diagram of a stress relaxation test method based on JCBA T309: 2001 (provisional).

A preferred embodiment of the copper alloy sheet material of the present invention will be described in detail. Here, “copper alloy material” means a copper alloy material (before processing and having a predetermined alloy composition) processed into a predetermined shape (for example, plate, strip, foil, bar, wire, etc.) Means. Among them, the plate material refers to a material having a specific thickness and being stable in shape and having a spread in the surface direction, and in a broad sense, includes a strip material. In the present invention, the thickness of the plate material is not particularly limited, but considering the fact that the effect of the present invention is better manifested and suitable for practical use, it is preferably 0.01 to 1.0 mm. 0.05 to 0.5 mm is more preferable.
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 strip. In the present invention, the pipe material can also be interpreted and handled as a plate material.

[Area ratio of Cube orientation]
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, it has been found that it is effective to increase the ratio of crystal orientation in which work hardening hardly occurs in bending deformation. That is, in the crystal orientation analysis in the EBSD measurement in the thickness direction of the plate material, it was found that when the area ratio of the Cube orientation {001} <100> is 5% to 50%, good bending workability is exhibited. The present invention has been completed based on the findings. When the area ratio of the Cube orientation is equal to or greater than the lower limit, the above-described effects are sufficiently exhibited. Moreover, it is preferable that it is below the said upper limit, since the cold rolling after a recrystallization process does not need to be performed with a low processing rate, and an intensity | strength does not fall remarkably. From the above viewpoint, the preferable range of the area ratio of the Cube orientation {001} <100> is 7 to 47%, more preferably 10 to 45%.

[Direction other than Cube direction]
In addition to the Cube orientation in the above range, S orientation {2 3 1} <3 4 6>, Copper orientation {1 2 1} <1 1 1>, D orientation {4 11 4} <11 8 11>, Brass orientation {1 1 0} <1 1 2>, Goss orientation {1 1 0} <0 0 1>, R1 orientation {3 5 2} <3 5 8>, RDW orientation {1 0 2} <0 1 0 > Etc. occur. In the present invention, if the area ratio of the Cube azimuth is within the above range with respect to the observed area of all azimuths, it is allowed to include these azimuth components.

[EBSD method]
In the present specification, the crystal orientation display method is as follows: the longitudinal direction (LD) of the copper alloy plate material (equal to the rolling direction (RD) of the plate material) is the X axis, the plate width direction (TD) is the Y axis, and the thickness direction of the plate material. Takes a rectangular coordinate system whose Z axis is {equal to the rolling normal direction (ND) of the plate material}, and is perpendicular to the Z axis (parallel to the rolling surface (XY surface)) in each region in the copper alloy plate material Using the index of the face (h k l) and the index [u v w] of the crystal plane perpendicular to the X axis (parallel to the YZ plane), it is expressed in the form of (h k l) [u v w] . In addition, as for (1 3 2) [6 -4 3] and (2 3 1) [3 -4 6], etc. It uses {h k l} <u v w> to represent parenthesis symbols.
The EBSD method was used for the analysis of the crystal orientation in the present invention. The EBSD method is an abbreviation of Electron Backscatter Diffraction (electron backscatter diffraction), which is a crystal orientation analysis technique using reflected electron Kikuchi line diffraction that occurs when a sample is irradiated with an electron beam in a scanning electron microscope (SEM). It is. A sample area of 1 micron square containing 200 or more crystal grains was scanned in steps of 0.5 micron and the orientation was analyzed. The measurement area and scan step were adjusted according to the crystal grain size of the sample. The area ratio of each orientation is the ratio of the area within ± 10 ° from the ideal orientation of the Cube orientation {0 0 1} <1 0 0> to the total measured area. 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. Further, since the azimuth distribution changes in the plate thickness direction, it is preferable that the azimuth analysis by EBSD takes an average for any number of points in the plate thickness direction.
The area ratio of each azimuth is calculated by dividing the area of a region whose deviation angle from each ideal azimuth is within 10 ° by the measurement area.
Regarding the deviation angle from the ideal orientation, the rotation angle is calculated around a common rotation axis, and is set 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 can be calculated about all rotation axes. The rotation axis is the smallest one that can be expressed at any angle. The deviation angle is calculated for all measurement points, and the total area of crystal grains with orientations within 10 ° from each orientation is the total measurement area. Divided by 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, but is too small for the measured width. Use rate. The azimuth distribution is measured from the surface of the copper alloy sheet, and when the azimuth distribution changes in the sheet thickness direction, the azimuth analysis by EBSD refers to a value obtained by averaging several points in the sheet thickness direction.

Here, the characteristics of the EBSD measurement will be described as contrast with the X-ray diffraction measurement.
The first point is that ND // (111), (200), (220) that can be measured by the X-ray diffraction method satisfies the Bragg diffraction conditions and provides sufficient diffraction intensity. ), (311), and (420) planes, and the deviation angle from the Cube orientation corresponds to 15 to 30 °, such as ND // (511) plane and ND // (951) plane. The crystal orientation expressed by a high index cannot be measured. That is, by adopting EBSD measurement, for the first time, information on the crystal orientation expressed by these high indices can be obtained, and the relationship between the specified metal structure and the action becomes clear.
Second, X-ray diffraction measures the amount of crystal orientation contained within about ± 0.5 ° of ND // {hkl}, whereas the EBSD measurement uses the Kikuchi pattern. Information on a wide range of metal structures, not limited to a specific crystal plane, is obtained comprehensively, and it becomes clear that the entire alloy material is difficult to identify 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 measurement of EBSD was performed with respect to the ND direction of a copper alloy board | plate material.

[X-ray diffraction intensity]
In the present invention, when the X-ray diffraction intensity from the {200} plane on the surface of the alloy plate is I {200} and the X-ray diffraction intensity from the {200} plane of the pure copper standard powder is I ₀ {200}, It is preferable to satisfy the formula (a), and it is more preferable to have a crystal orientation that satisfies the formula (b) below.
I {200} / I ₀ {200} ≧ 1.3 Formula (a)
I {200} / I ₀ {200} ≧ 2.5 Formula (b)

[Ti]
In the present invention, by controlling the amount of titanium (Ti) added to copper (Cu), the Cu—Ti compound can be precipitated and the strength of the copper alloy can be improved. The Ti content is 1.0 to 5.0 mass%, preferably 2.0 to 4.0 mass%. If this element is added in an amount greater than this specified range, the electrical conductivity is lowered, and if it is less, the strength is insufficient. In addition, what contains Ti as a 2nd alloy component like the copper alloy which concerns on this invention may be called "Ti type copper alloy."

[Sub-additive elements]
Next, the effect of the secondary additive element on this alloy will be described. Preferred secondary additive elements include Sn, Zn, Ag, Mn, B, P, Mg, Cr, Zr, Si, Fe, and Hf. The content of these sub-added elements is 1% by mass or less in the total amount of at least one selected from the group consisting of Sn, Zn, Ag, Mn, B, P, Mg, Cr, Zr, Si, Fe and Hf It is preferable because it does not cause a harmful effect of lowering the conductivity. In order to fully utilize the additive effect and not lower the electrical conductivity, the total amount is preferably 0.005 to 1.0% by mass, more preferably 0.01 to 0.9% by mass, It is especially preferable that it is 0.03 mass%-0.8 mass%. Below, the example of the addition effect of each element is shown.

(Mg, Sn, Zn)
Addition of Mg, Sn and Zn improves the stress relaxation resistance. The stress relaxation resistance is further improved by the synergistic effect when each of them is added together than when they are added alone. In addition, the solder embrittlement is remarkably improved.

(Mn, Ag, B, P)
When Mn, Ag, B, and P are added, the hot workability is improved and the strength is improved.

(Cr, Zr, Si, Fe, Hf)
Cr, Zr, Si, Fe, and Hf are finely precipitated as a compound or a simple substance, 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.

[Method for producing copper alloy sheet]
Next, preferable production conditions for the copper alloy sheet of the present invention will be described.
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 water cooling [Step] 4], chamfering [Step 5], cold rolling [Step 6] in this order to make a thin plate, intermediate solution heat treatment [Step 9] in a temperature range of 700-1000 ° C. to re-solidify solute atoms After that, the required strength is satisfied by aging precipitation heat treatment [Step 10] and finish cold rolling [Step 11]. In this series of steps, the texture of the copper alloy sheet is roughly determined by recrystallization that occurs during the intermediate solution heat treatment [Step 9], and the final rotation is caused by the rotation of the orientation that occurs during the finish rolling [Step 11]. To be determined.

  In contrast to the conventional method described above, in one embodiment of the present invention, after hot rolling [Step 3], water cooling [Step 4], chamfering [Step 5], and cold rolling [Step 6] are performed at a rolling rate of 80. % Annealing is performed at a temperature rising rate of 10 to 30 ° C./second until reaching 600 to 800 ° C., and then rapidly cooled at 200 ° C./second or more [process] 7] and further cold rolling [Step 8] at a processing rate of 2 to 50% increases the area ratio of the Cube orientation in the recrystallized texture of the intermediate solution heat treatment [Step 9]. Further, 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] may be performed.

Hereinafter, an embodiment of the present invention in which the conditions of each step are set in more detail will be described.
At least 1.0 to 5.0% by mass of Ti, other elements added as appropriate, are added as appropriate, and the copper alloy material consisting of Cu and inevitable impurities is melted in a high-frequency melting furnace. Then, this is cast [Step 1] at a cooling rate of 0.1 to 100 ° C./sec to obtain an ingot. This is subjected to homogenization heat treatment [Step 2] at 800 to 1020 ° C. for 3 minutes to 10 hours, followed by hot working [Step 3] at 1024 to 700 ° C. and then water quenching (corresponding to water cooling [Step 4]). . Thereafter, if necessary, chamfering [Step 5] may be performed to remove oxide scale. Thereafter, cold rolling with a processing rate of 80 to 99.8% [Step 6], then heating at a heating rate of 10 to 30 ° C./second, reaching 600 to 800 ° C., and then 200 ° C./second or more Intermediate annealing [Step 7] is performed, followed by cold rolling [Step 8] at a processing rate of 2 to 50%, and intermediate solution heat treatment [Step 9] at 600 to 1000 ° C. for 5 seconds to 1 hour. ]I do. Thereafter, an aging precipitation heat treatment at 400 to 700 ° C. for 5 minutes to 10 hours [Step 10], finish cold rolling with a processing rate of 3 to 25% [Step 11], and 200 to 600 ° C. for 5 seconds to 10 hours. Conditioning annealing [Step 12] may be performed. By the above method, the copper alloy sheet of the present invention can be obtained.

In the present embodiment, in the hot rolling [Step 3], in the temperature range from the reheating temperature to 700 ° C., the processing for breaking the cast structure and segregation into a uniform structure and the dynamic recrystallization are performed. Processing for miniaturization 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, and then cold rolling [Step 8] is performed at a processing rate of 2 to 50%. In the recrystallized texture, the area ratio of the Cube orientation increases. Here, when the heat treatment arrival temperature of the intermediate annealing [Step 7] before the intermediate solution [Step 9] is higher than the specified value of the present invention, an oxide scale is formed, which is not preferable. Therefore, in the intermediate annealing [Step 7] The heat treatment ultimate temperature is 600 to 800 ° C. Among them, although it is difficult to determine unambiguously, it is possible to determine the Cube orientation area ratio by specifying the annealing temperature in intermediate annealing [Step 7] and adjusting the processing rate in cold rolling [Step 8]. There is a tendency to increase. That is, in the intermediate annealing [Step 7], the temperature is not maintained at the annealing reaching temperature, but is heated at a predetermined temperature increase rate, and when the target annealing temperature is reached, the cooling is immediately performed at the predetermined cooling rate.
Here, when the rate of temperature increase in the intermediate annealing [Step 7] is slower than 10 ° C./second, grain growth proceeds, the crystal grains become coarse, and bending wrinkles increase. When the rate of temperature rise is faster than 30 ° C./second, the Cube orientation does not develop sufficiently and the bending workability is poor. Further, when the ultimate temperature is lower than 600 ° C., the Cube orientation does not develop and the bending workability is inferior, and when it is higher than 800 ° C., the grain growth progresses, the crystal grains become coarse and bending wrinkles become large, resulting in poor characteristics. Further, as described above, dislocation occurs around coarse crystallized products and precipitates generated by casting by performing strong processing such as cold rolling [Step 6] at a processing rate of 80 to 99.8%. In the intermediate solution heat treatment [Step 9] in which strain is introduced and the Cube orientation is grown, there is a possibility that the orientation rotation is inhibited. However, by performing the intermediate annealing [Step 7], the dislocation, Therefore, the inhibition of Cube orientation growth is suppressed in the intermediate solution heat treatment [Step 9].

Next, cold rolling [Step 8] is performed at a processing rate of 2 to 50%. Here, if the processing rate is lower than 2%, the processing strain is small, the crystal grain size becomes coarse in the intermediate solution heat treatment [Step 9], the bending wrinkles become large, and the characteristics are inferior. When the processing rate is higher than 50%, the Cube orientation is not sufficiently developed and the bending workability is inferior.
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. Here, the treatment temperature of the aging precipitation heat treatment [Step 10] is lower than the treatment temperature of the intermediate solution heat treatment [Step 9]. Further, the treatment temperature of the temper annealing [Step 12] is lower than the treatment temperature of the intermediate solution heat treatment [Step 9].
In order to increase the area ratio of the Cube orientation in the recrystallized texture, the finish cold working [Step 11] is performed. In addition, it contributes to the development of the Cube orientation by controlling the crystal orientation to a certain direction.
By adding further processing strain by cold rolling [Step 6] and applying intermediate heat treatment [Step 7], a heating rate of 10 to 30 ° C./second, an ultimate temperature of 600 to 800 ° C., and a rapid cooling process after the arrival. The Cube orientation area ratio increases in the recrystallized texture produced in the intermediate solution treatment [Step 9]. The purpose of the intermediate annealing [Step 7] is to obtain a sub-annealed structure that is not completely recrystallized but partially recrystallized. The purpose of cold rolling [Step 8] is to introduce microscopically non-uniform strain by rolling at a processing rate of 2 to 50%. The effect of the intermediate annealing [Step 7] and cold rolling [Step 8] enables the growth of the Cube orientation in the intermediate solution treatment [Step 9]. Usually, the heat treatment such as the intermediate solution treatment [Step 9] is mainly aimed at reducing the strength by recrystallizing the copper alloy plate material in order to reduce the load in the next step. Is different.

The processing rate in each of the rolling processes (also referred to as rolling reduction and cross-sectional reduction rate. The rolling ratio in the following comparative examples is also synonymous) is the thickness t ₁ before the rolling process and the thickness t after the rolling process. ₂ is used to mean a value calculated as in the following equation.
Processing rate (%) = ((t ₁ −t ₂ ) / t ₁ ) × 100
If necessary, the surface of the material may be subjected to chamfering for scale, acid cleaning, or the like. If the shape after rolling is not good, correction with a tension leveler or the like may be performed as necessary.
After each heat treatment and rolling, even if acid cleaning or surface polishing is performed according to the state of oxidation or roughness of the plate material, and correction is performed with a tension leveler according to the shape, the Cube orientation {0 0 1} <1 0 0 If the area ratio of> is within the range of the present invention, there is no problem.

[Characteristics of copper alloy sheet]
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 the present invention, the copper alloy sheet preferably has the following characteristics.
-It is preferable that 0.2% yield strength is 850 Mpa or more. More preferably, it is 950 MPa or more. The upper limit of 0.2% proof stress is not particularly limited, but is usually 1000 MPa or less. The detailed measurement conditions are as described in the examples unless otherwise specified.
The bending workability is 90 ° W. The value (r / t) obtained by dividing the minimum bending radius (r) that can be bent with small wrinkles by the plate thickness (t) is 1 or less in a 90 ° W bending test. It is preferable. Regarding bending wrinkles, the wrinkle spacing is preferably 20 μm or less for GW and 25 μm or less for BW. More preferably, the wrinkle spacing is 15 μm or less for GW and 20 μm or less for BW. The detailed measurement conditions are as described in the examples unless otherwise specified. Here, in the specimen cut out perpendicular to the rolling direction, W-bent so that the bending axis is perpendicular to the rolling direction is GW (Good Way), and the bending axis is parallel to the rolling direction. W bent is called BW (Bad Way).
-It is preferable that electrical conductivity is 5% IACS or more. More preferably, the electrical conductivity is 10% IACS or more. The upper limit value of the conductivity is not particularly limited, but is usually 30% IACS or less. The detailed measurement conditions are as described in the examples unless otherwise specified.
-The Young's modulus is preferably 90 to 120 GPa and the deflection coefficient is preferably 80 to 110 GPa. More preferably, the Young's modulus is 100 to 110 GPa and the deflection coefficient is 90 to 100 GPa. The detailed conditions are as described in the examples unless otherwise specified.
-Good stress relaxation characteristics of 5% or less can be realized by the present invention. The detailed conditions are as described in the examples unless otherwise specified.

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

Example 1
Inventive Example 2 to Inventive Example 21, Comparative Example 1 to Comparative Example 17, so as to have the composition shown in Table 1, the main raw materials Cu and Ti, depending on the test example, other auxiliary additive elements are blended, Melted and cast. That is, an alloy composed of Ti and the like shown in Table 1 and the balance consisting of Cu and inevitable impurities is melted in a high-frequency melting furnace and cast at a cooling rate of 0.1 to 100 ° C./second [Step 1]. As a result, an ingot was obtained. This was subjected to a homogenization heat treatment [Step 2] at 800 to 1020 ° C. for 3 minutes to 10 hours, followed by hot working [Step 3] at 1020 to 700 ° C. Thereafter, water quenching (corresponding to water cooling [step 4]) was performed, and chamfering [step 5] was performed to remove oxide scale. Thereafter, cold rolling with a processing rate of 80 to 99.8% [Step 6], then heating at a heating rate of 10 to 30 ° C./second, reaching 600 to 800 ° C., and then rapidly cooling at 200 ° C./second or more. Intermediate annealing [Step 7] is performed, and further cold rolling [Step 8] with a processing rate of 2 to 50% and intermediate solution treatment [Step 9] at 600 to 1000 ° C. for 5 seconds to 1 hour are performed. . Next, an aging precipitation heat treatment [Step 10] is performed at 400 to 700 ° C. for 5 minutes to 1 hour, and finish cold rolling [Step 11] at a rolling rate of 3 to 25%, and 200 to 600 ° C. for 5 seconds to 10 seconds. Tempering annealing [Step 12] was performed to obtain a specimen. In the comparative example, as shown in Table 2, there are those carried out by removing from the above conditions by intermediate annealing [Step 7] and cold rolling [Step 8]. Tables 1 and 2 show the compositions of these test materials, the conditions in the intermediate annealing [Step 7] and the cold rolling [Step 8], and the properties obtained for the present invention example and the comparative example. 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. In addition, the processing temperature in the hot processing [Step 3] was measured with a radiation thermometer installed on the entry side and the exit side of the rolling mill.

  The following characteristics were investigated for these test materials. Here, the thickness of the test material was 0.15 mm. The evaluation results are shown in Table 2.

a. Area ratio of Cube orientation and S orientation Measurement was performed by EBSD method under the conditions of a measurement area of 0.08 to 0.15 μm ² and a scan step of 0.5 to 1 μm. The measurement area was adjusted based on the inclusion of 200 or more crystal grains. The scan step was adjusted according to the crystal grain size. When the average crystal grain size was 15 μm or less, the scan step was performed at 0.5 μm step, and when it was 30 μm or less, the scan step was performed at 1 μm step. The electron beam was generated from thermionic electrons from the W filament of the scanning electron microscope.
As a measuring device of the EBSD method, OIM5.0 (trade name) manufactured by TSL Solutions Co., Ltd. was used.
b. Bending workability GW (Good Way) is obtained by cutting W to be 10 mm wide and 35 mm long perpendicular to the rolling direction, and bending it so that the bending axis is perpendicular to the rolling direction, and the bending axis is parallel to the rolling direction. BW (Bad Way) was obtained by bending W so that the bent portion was observed with a 50 × optical microscope, and the presence or absence of cracks was investigated. Those having no cracks were judged as ◯ (“good”), and those with cracks were judged as × (“poor”). The bending angle of each bent portion was 90 °, and the inner radius of each bent portion was 0.15 mm. That is, the minimum bending radius (r) was 0.15 mm, the plate thickness (t) was 0.15 mm, and the ratio (r / t) was 1.
c. Judgment of bending wrinkles Judgment of bending wrinkles on the surface of the bent portion of the sample subjected to the 90 ° W bending test and the 180 ° adhesion bending test was performed. The sample was filled with resin, and the bending cross section was observed by SEM. The size of the wrinkles was measured from the size between the grooves of the wrinkles, which was observed by cross-sectional observation. With respect to bending wrinkles, if the wrinkle spacing was 20 μm or less for GW and 25 μm or less for BW, it was determined to be acceptable.

d. 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.
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.
f. Young's modulus The test piece was cut out from the rolling parallel direction and processed so that the width was 20 mm, the length was 150 mm, and the parallelism was 0.05 mm or less per 50 mm. The Young's modulus is a value calculated from the slope of the elastic region of the stress-strain diagram obtained by a tensile test.
g. Deflection coefficient The test piece was cut out from the rolling parallel direction, the width was 10 mm, the plate thickness was 0.1 to 0.65 mm, and the length was 100 times or more of the plate thickness according to the Japan Copper and Brass Association technical standard. In accordance with JIS H 3130, the inclination in the elastic region in the stress-strain diagram when the beam (cantilever) is bent is measured twice for each front and back of each test piece, and the average value is calculated. Indicated.
h. X-Ray Diffraction Intensity The diffraction intensity around one rotation axis was measured with respect to the sample by the reflection method. Copper was used for the target, and Kα X-rays were used. Measurement was performed under the conditions of a tube current of 20 mA and a tube voltage of 40 kV. After removing the background of the diffraction intensity in the diffraction angle and diffraction intensity profile, an integrated diffraction intensity obtained by combining Kα1 and Kα2 of each peak was obtained, and I {200 } And I ₀ {200} diffraction intensity ratio I {200} / I ₀ {200}.

i. Stress relaxation rate [SRR]
In accordance with the former Japan Electronic Materials Industry Association Standard (EMAS-3003), the measurement was performed under the conditions of 150 ° C. × 1000 hours as shown below. An initial stress of 80% of the proof stress was applied by the cantilever method.
2A and 2B are explanatory diagrams of a stress relaxation characteristic test method. FIG. 2A shows a state before heat treatment, and FIG. 2B 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 was held for 1000 hours in a thermostat at 0.99 ° C., the position of the test piece 2 after removing the load, the distance from the reference H _t as shown in FIG. 1 (b). 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 × 100.
As a similar test method, the following method is also applicable; “JCBA T309: 2001 (provisional); copper and copper alloy sheet strip, which is the technical standard proposal of the Japan Copper and Brass Association (JCBA)” Stress relaxation test method by bending "American Society for Testing and Materials" ASTM E328; Standard Test Methods for Stress Test, etc .;
FIG. 3 is an explanatory diagram of a stress relaxation test method using a downward deflection type cantilever-type deflection displacement load test jig based on the above-mentioned JCBA T309: 2001 (provisional). Since the principle of this test method is the same as that of the test method using the test stand of FIG. 2, the value of the stress relaxation rate is almost the same.
In this test method, first, a test piece 11 is attached to a test jig (test apparatus) 12, given displacement is given at room temperature, unloaded after being held for 30 seconds, and the bottom surface of the test jig 12 is used as a reference surface 13, and this surface 13 and the distance between the deflection load point of the specimen 11 is measured as H _i. When a predetermined time elapses, the test jig 12 is taken out from the thermostat or heating furnace to room temperature, and the flexible load bolt 14 is loosened and unloaded. After cooling the specimens 11 to room temperature, to measure the distance H _t of the deflection load point of the reference plane 13 and the specimen 11. After the measurement, the deflection displacement is given again. In the figure, 11 represents a test piece at the time of unloading, and 15 represents a test piece at the time of bending load. Obtaining a permanent deflection displacement [delta] _t by the following equation.
δ _t = _H i -H _t
From this relationship, the stress relaxation rate (%) was calculated as δ _t / δ ₀ × 100.
Δ ₀ is the initial deflection displacement of the test piece necessary to obtain a predetermined stress, and is calculated by the following equation.
δ ₀ = σl _s ² /1.5Eh
Here, σ: surface maximum stress (N / mm ² ) of the test piece; h: plate thickness (mm), E: deflection coefficient (N / mm ² ), l _S : span length (mm).

As shown in Table 2, in the production methods of Invention Example 2 to Invention Example 21, intermediate annealing [Step 7] is a heating rate of 10 to 30 ° C./second, an ultimate temperature of 600 to 800 ° C., and water after reaching the temperature. It was heat-treated by quenching by quenching (cooling rate of 200 ° C./second or more). Thereafter, it was subjected to a treatment in cold rolling [Step 8] at a processing rate of 2 to 50%. In Comparative Example 1 to Comparative Example 17, the case where the regulation in the production method of the present invention was not satisfied was shown. In Comparative Examples 5, 6, 16, and 17, the Ti component is out of range, and the intermediate annealing [Step 7] in Comparative Examples 1 to 17 is performed in Comparative Examples 1, 4, 6, 8, 11, 12, 16, 17, the temperature rising rate was out of range, and in Comparative Examples 3-6, 10, 11, 14-17, the ultimate temperature was out of range. Moreover, in Comparative Examples 2, 6, 7, 9, 12, 13, 15 to 16, the processing rate of the cold rolling [Step 8] was out of the range. Further, as shown in Table 1, in Comparative Example 10, the amount of the third element added was large beyond the specified range of 0.005 to 1.0%.

As shown in Table 2, Invention Example 2 to Invention Example 21 were excellent in bending workability and yield strength. However, as shown in Comparative Examples 1 to 17, when the conditions of the present invention were not satisfied, the characteristics were inferior. Invention Example 2 to Invention Example 21 promotes the crystal orientation rotation of titanium copper by heat treatment in a temperature range lower than the solid solution temperature, finally greatly increases the Cube orientation area ratio and improves bendability. did. Invention Example 2 to Invention Example 21 all had a Cube orientation of 5% or more. Bending surface part wrinkles of Invention Example 2 to Invention Example 21 had a size of GW ≦ 20 μm and BW ≦ 25 μm, had no cracks, and had small bending wrinkles, and was excellent in bending workability. The Young's modulus and the deflection coefficient were also within the specified ranges.

On the other hand, in Comparative Examples 1 to 7, Comparative Examples 9 and 10, Comparative Examples 12 to 14, and Comparative Examples 16 and 17, cracks were generated on the bending surface. The Cube azimuth | direction area ratio of Comparative Examples 1-17 was outside the range of 5 to 50% which is a regulation value. Among them, Comparative Example 5 having a low Cube orientation area ratio was inferior in bending workability, and Comparative Example 8 having a high Cube orientation area ratio was inferior in yield strength.
The X-ray diffraction integrated intensity ratio I {200} / I ₀ {200} was 1.3 or less of the specified value in all of Comparative Examples 1 to 17 except for Comparative Example 8 and Comparative Example 11. . Comparative Example 8 and Comparative Example 11 showed 1.3 or more, but the proof stress was inferior.
The Ti contents of Comparative Examples 5, 6, 16, and 17 were outside the specified range of 1.0 to 5.0%.
In Comparative Examples 1 to 17, any one of the temperature increase rate, ultimate temperature, and cold rolling rate of intermediate annealing was out of the specified value range, and the characteristics were out of the specified range. In comparative example 1, comparative example 3, comparative example 4, comparative examples 7-9, comparative example 11, and comparative examples 13-17, it was outside the range of 90-120 GPa which is a regulation value of Young's modulus. Moreover, in Comparative Example 1, Comparative Examples 3-8, Comparative Examples 10-11, and Comparative Examples 13-17, it was outside the range of 80-110 GPa which is a regulation value of a deflection coefficient. Further, in Comparative Example 10, the amount of the third element added was larger than the specified value, and the conductivity was lowered. In Comparative Example 14, the amount of the third element added was smaller than the specified value, Since the temperature reached in annealing was too high, cracks and wrinkles were generated in the bending process, the yield strength (strength) was low, and the Young's modulus and deflection coefficient were too high. In Comparative Example 15, both GW and BW are bent without cracks, and the proof stress satisfies the specified value, but wrinkles on the bent surface are large, the Young's modulus and deflection coefficient exceed the upper limit of the specified value, and the characteristics are inferior. It was. In Comparative Examples 16 and 17, both the Ti content and the manufacturing process were out of the specified range, and both the Cube orientation area ratio and the I {200} diffraction intensity were out of the specified range.
Comparative Example 3～6,9,14～17 is outside the area ratio of the Cube orientation, in order to further (increase the stress relaxation resistance) element is not added, the present invention Example 2-21 In comparison, the stress relaxation resistance was inferior.

  In the present invention, by controlling the rate of temperature rise in intermediate annealing [Step 7], the ultimate temperature, the processing rate of cold rolling [Step 8], a target structure can be obtained, and both bendability and strength can be achieved, Furthermore, it is possible to obtain a titanium-copper alloy plate material that satisfies the wrinkle size, Young's modulus, and deflection coefficient of the bent surface portion.

(Conventional example)
Except for not performing intermediate annealing [Step 7] and subsequent cold rolling [Step 8] for the alloy composition shown in Table 3 (the balance is copper (Cu)), the same as in Example 1 above. A copper alloy sheet was prepared. 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 also shown in Table 3.

  As is apparent from Table 3, the copper alloy sheet materials of Conventional Examples 1 to 3 manufactured without intermediate annealing [Step 7] and subsequent cold rolling [Step 8] have a predetermined alloy composition and these two Even when manufacturing conditions other than the process (each process and condition) were adopted, the area ratio of the Cube orientation was small, the bending workability was inferior, and cracks or remarkably large wrinkles were generated.

  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) ... Japanese Patent Application Laid-Open No. 2011-26635 Condition of Invention Example 1 A vertical semi-continuous casting machine that melts a copper alloy having a composition containing 3.25% by mass of Ti and the balance being Cu. Was used for casting.
The obtained slab is heated to 950 ° C., hot-rolled while lowering the temperature from 950 ° C. to 400 ° C., made into a plate material having a thickness of about 9 mm, and then rapidly cooled by water cooling, and then the surface oxide layer Was removed (face cut) by mechanical polishing. The thickness of the plate material is determined from the relationship between the rolling ratio of each subsequent cold rolling and the final plate thickness. Subsequently, after performing the first cold rolling at a rolling rate of 84%, it was subjected to an intermediate annealing treatment. Intermediate annealing (heat treatment) was performed at 550 ° C. for 6 hours. The electrical conductivity before and after the intermediate annealing was Eb and Ea, the Vickers hardness was Hb and Ha, respectively, and Ea / Eb was 3.3 and Ha / Hb was 0.72. Thereafter, the second cold rolling was performed at a rolling rate of 86%.
Next, a solution treatment is performed by holding at 900 ° C. for 15 seconds in accordance with the composition of the alloy so that the average crystal grain size (by the cutting method of JIS H0501) on the surface of the rolled plate is greater than 5 μm and less than 25 μm. It was.
Subsequent intermediate rolling was omitted and not performed.
Next, an aging treatment was performed at 450 ° C. The aging treatment time was adjusted to a time at which the hardness peaked with aging at 450 ° 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 15%. Further, low-temperature annealing was performed in an annealing furnace at a furnace temperature of 450 ° C. for a holding time of 1 min. 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 differs from the above-described example according to the present invention in terms of manufacturing conditions in that the processing temperature of the intermediate annealing treatment is low and the processing time is long, and in the second cold rolling after the intermediate annealing treatment. The difference is that the rolling rate is large, and the Cube orientation is less than 5%, and the bending property in the vertical direction of rolling does not satisfy the required characteristics of the present invention.

(Comparative Example 102) ... Conditions of JP 2010-126777 A Example 1 3. Using a vertical semi-continuous casting machine, melting a copper alloy containing 3.18% by mass of Ti and the balance being Cu. To obtain a cast piece having a thickness of 60 mm.
The slab was heated to 950 ° C. and extracted, and hot rolling was started. In this hot rolling, the pass schedule was set so that the rolling rate in the temperature range of 750 ° C. or higher was 60% or higher and the rolling was performed in the temperature range of less than 700 ° C. In addition, the hot rolling rate in less than 700 degreeC-500 degreeC was 42%, and the final pass temperature of hot rolling was between 600 degreeC and 500 degreeC. The total hot rolling rate from the slab was about 95%. After hot rolling, the surface oxide layer was removed (faced) by mechanical polishing.
Next, after cold rolling at a rolling rate of 98%, solution treatment was performed. In this solution treatment, an average crystal grain size after solution treatment (a twin boundary is not regarded as a grain boundary) is 5 to 25 μm in a temperature range of 750 to 1000 ° C. according to the alloy composition. The temperature was set at 30 ° C. or more higher than the solid solution wire of the alloy composition, and the heat treatment was performed by adjusting the holding time in the range of 5 seconds to 5 minutes. Specifically, heat treatment was performed at 900 ° C. for 15 seconds.
Next, the sheet material after the solution treatment was cold-rolled at a rolling rate of 15%. As a preliminary experiment, the sheet material obtained in this way was aged in a temperature range of 300 to 550 ° C. for up to 24 hours. performing processing experiments, the maximum becomes hardness aging treatment conditions depending on the alloy composition (aging temperature T _{M (°} C.), aging time t _{M (min),} maximum hardness H _{M (HV))} was grasped. The aging temperature is set to a temperature within the range of T _M ± 10 ° C., the aging time is shorter than t _M , and the hardness after aging is in the range of 0.90 H _{M to} 0.95 H _M. Set to time.
Next, the plate material after the aging treatment was subjected to finish cold rolling at a rolling rate of 10%, and then subjected to low-temperature annealing that was held in a 450 ° C. annealing furnace for 1 minute.
In this way, a copper alloy sheet was obtained. If necessary, chamfering was performed in the middle, and the thickness of the copper alloy sheet was adjusted to 0.15 mm. This was designated as sample c02.
The obtained specimen c02 differs from the above-described example according to the present invention in terms of manufacturing conditions in that hot rolling is performed in two stages, and intermediate annealing before the solution treatment [Step 7] and cold rolling. The solution treatment is performed without performing [Step 8], the heat treatment after the cold rolling [Step 6] is different from the cold rolling step, the Cube orientation is less than 5%, and the vertical direction of the rolling is The bending workability did not satisfy the required characteristics of 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. 2010-195120 filed in Japan on August 31, 2010, the contents of which are incorporated herein by reference. Capture as part.

1 Test piece when initial stress is applied 2 Test piece after removing load 3 Test piece when stress is not applied 4 Test stand 11 Test piece (when unloaded)
12 Test Jig 13 Reference Surface 14 Deflection Load Bolt 15 Test Piece (When Deflection Load)

Claims (9)

A copper alloy plate material containing 1.0 to 5.0 mass% of Ti and the balance of copper and inevitable impurities, and in the crystal orientation analysis in EBSD measurement, the area of Cube orientation {0 0 1} <1 0 0> A copper alloy sheet having a rate of 10 to 50%. The copper alloy sheet is heated at a temperature rising rate of 10 to 30 ° C./second and reaches 600 to 800 ° C. (excluding 600 ° C.) in the intermediate annealing in the cold rolling process at the time of manufacture. The copper alloy sheet according to claim 1, wherein: The copper alloy further comprises 0.005 to 1.0 mass% in total of at least one selected from the group consisting of Sn, Zn, Ag, Mn, B, P, Mg, Cr, Zr, Si, Fe, and Hf. copper alloy sheet according to claim 1 or 2, characterized in that it contains. 0.2% proof stress is 850 MPa or more, and bending workability is 90 ° W. The minimum bending radius (r, mm) that can be bent with little cracks in the bending test is 90 mm. The copper alloy sheet material according to any one of claims 1 to 3, wherein a divided value (r / t) is 1 or less. Shows the displacement amount at the time of adding the constant stress to the plate material, rate Young measured by tensile test is 90～120GPa, bending coefficient was measured by bending test is 80～110GPa, any claim 1-4 The copper alloy sheet material according to claim 1. It is a method of manufacturing the copper alloy sheet | seat of any one of Claims 1-5 , Comprising: It is 0.1-100 degree-C / sec cooling to the copper alloy raw material which consists of an alloy component composition which gives the said copper alloy sheet | seat material. Casting at a speed [Step 1], homogenizing heat treatment at 800 to 1020 ° C. for 3 minutes to 10 hours [Step 2], hot rolling at 1020 to 700 ° C. [Step 3], water cooling [Step 4], processing rate 80 to 99 .8% cold rolling [step 6], intermediate annealing that heats at a heating rate of 10 to 30 ° C./second, reaches 600 to 800 ° C., and then rapidly cools at 200 ° C./second or more [step 7], 2 A method for producing a copper alloy sheet comprising: cold rolling with a processing rate of ˜50% [Step 8] and intermediate solution heat treatment [Step 9] at 600 to 1000 ° C. for 5 seconds to 1 hour in this order. . After the intermediate solution heat treatment [Step 9], aging precipitation heat treatment [Step 10] at 400 to 700 ° C. for 5 minutes to 10 hours, finish cold rolling with a processing rate of 3 to 25% [Step 11], and Refining annealing [Step 12] is performed in this order at 200 to 600 ° C. for 5 seconds to 10 hours. Here, the treatment temperature of the aging precipitation heat treatment [Step 10] is the treatment of the intermediate solution heat treatment [Step 9]. The method for producing a copper alloy sheet according to claim 6 , wherein the temperature of the temper annealing [Step 12] is lower than the temperature of the intermediate solution heat treatment [Step 9]. . The copper alloy component which consists of a copper alloy board | plate material of any one of Claims 1-5 . The connector which consists of a copper alloy board | plate material of any one of Claims 1-5 .

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