JP2011117034A - Copper-alloy material - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a copper-alloy material having excellent bending workability and high strength and suitable to parts for electric and electronic machines, for example, load frame, connector, terminal material, etc., specially, the connector, terminal material, relay, switch, etc., for fitting to an automobile. <P>SOLUTION: The copper-alloy material for electric and electronic parts excellent in the high strength and the bending workability, is the copper-alloy material composed of 0.5-5.0 mass% either one or the total of both of Ni or Co and 0.2-1.5% Si, respectively, and the balance Cu with inevitable impurities, wherein the area ratio of crystal grain Cube-orientation [001]<100> is ≥10% and the area ratio of crystal grain RDW orientation [920]<100> is ≥10%. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a copper alloy material for electrical and electronic parts, and more particularly to a copper alloy material having high strength and excellent bending workability, which is suitable for connection parts such as automobile terminals and connectors.

  In recent years, demands for downsizing and weight reduction of electronic devices have increased, and further downsizing and weight reduction have been advanced. For example, connector terminals, which are parts of electronic equipment, have been reduced in height and pitch, and as a result, copper alloy materials used for these connector terminals are required to have higher strength and superior bending workability. It is like that. Conventionally, beryllium copper has been widely used for copper alloys that require high strength and excellent bendability, but beryllium copper is very expensive and has strong toxicity to metal beryllium. Therefore, the amount of Corson alloy (Cu-Ni-Si alloy) used as an alloy that can be substituted for these materials is increasing.

Corson alloys are alloys in which the solubility limit of nickel silicide compounds (Ni ₂ Si) in copper changes with temperature, and are precipitation hardened alloys that harden by aging precipitation treatment, and have good heat resistance, electrical conductivity, and strength. is there.

  However, even in this Corson alloy, when the strength of the copper alloy material is improved, the conductivity and the bending workability are lowered. That is, in a high-strength Corson alloy, it is a very difficult task to achieve good conductivity and bending workability.

  For such a problem, as a high-strength copper alloy having excellent bending workability, Patent Document 1 improves bending workability by defining the size and distribution density of precipitates in the Corson alloy. . Moreover, in patent document 2, intensity | strength and a bending workability are improved by prescribing | regulating the crystal grain diameter of a Corson-type alloy. However, BW bending, which is performed with a bend line parallel to the rolling direction, is performed on connector materials, but these materials may not meet the strength and bending workability required by the market. There is a need for improvement.

  On the other hand, in recent years, attempts have been made to improve bending workability by controlling the texture. In Patent Document 3, bending workability is improved by controlling the area ratio of crystal grains having a Cube orientation. In Patent Document 4, bending workability is improved by increasing the (200) diffraction intensity of X-rays. In Patent Document 5, bending workability is improved by increasing the diffraction intensity of the (420) orientation of X-rays, that is, the area ratio of crystal grains having the (420) orientation. However, according to our knowledge, increasing the area ratio of crystal grains having Cube orientation, (200) orientation diffraction intensity, and (420) orientation diffraction intensity of X-rays certainly improves the bending workability. However, if these are increased, the work hardening coefficient when the material is deformed is small, and the crystal grain size becomes coarse, so that the strength may be lowered, and further improvement is demanded.

JP-A-6-184680 JP 2006-161148 A JP 2006-152392 A JP 2009-007666 A JP 2008-223136 A

  In view of the above-described problems, the object of the present invention is to provide excellent bending workability, high strength, and parts for electric and electronic equipment, such as lead frames, connectors, terminal materials, etc., particularly connectors for automobiles. It is to provide a copper alloy material suitable for a terminal material, a relay, a switch and the like.

  As a result of earnest research, we have determined the structure of precipitation type copper alloy materials (especially plate materials and strips) such as Corson, and the area ratio of crystal grains of Cube orientation and RDW (RD-Rotated-Cube orientation) orientations. It was found that excellent bending workability and high strength, which are required characteristics of terminals, connectors, etc., can be achieved at a high level by using a texture that is simultaneously increased to satisfy the values. The present invention has been made based on this finding.

That is, according to the present invention, the following means are provided.
(1) A copper alloy containing either 0.5 or 5 mass% of Ni or Co in total, 0.2 to 1.5 mass% of Si, and the balance of Cu and inevitable impurities A material having a high strength and excellent bending workability, characterized in that the area ratio of Cube-oriented crystal grains is 10% or more and the area ratio of RDW-oriented crystal grains is 10% or more. Copper alloy material for parts.

(2) 0.5 to 5.0% by mass in total of either one or both of Ni and Co, 0.2 to 1.5% by mass of Si, and 0.01 to 0.5% by mass of Cr, respectively A copper alloy material containing Cu and inevitable impurities, wherein the area ratio of the Cube-oriented crystal grains is 10% or more and the area ratio of the RDW-oriented crystal grains is 10% or more A copper alloy material for electrical and electronic parts with high strength and excellent bending workability.
(3) 0.5 to 5.0% by mass in total of either one or both of Ni and Co, 0.2 to 1.5% by mass of Si, Zn, Sn, Mg, Ag, Mn, Zr It is a copper alloy material containing one or two or more in total of 0.01 to 1.0% by mass, with the balance being Cu and inevitable impurities, and the area ratio of Cube-oriented crystal grains is 10% A copper alloy material for electrical and electronic parts having high strength and excellent bending workability, characterized in that the area ratio of crystal grains in the RDW orientation is 10% or more.
(4) 0.5 to 5.0 mass% in total of either one or both of Ni and Co, Si to 0.2 to 1.5 mass%, Cr to 0.01 to 0.5 mass%, Zn , Sn, Mg, Ag, Mn, Zr, a total of 0.01 to 1.0% by mass of one or more of Zr, each of which is a copper alloy material composed of Cu and inevitable impurities A copper alloy for electrical and electronic parts having high strength and excellent bending workability, characterized in that the area ratio of crystal grains of Cube orientation is 10% or more and the area ratio of crystal grains of RDW orientation is 10% or more material.

  The copper alloy material of the present invention has excellent bending workability and high strength, and is a component for electrical and electronic equipment, such as lead frames, connectors, terminal materials, etc., connectors and terminal materials for automobiles, relays, Suitable for switches and the like.

A preferred embodiment of the copper alloy 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. In addition, a board | plate material and a strip are demonstrated below as embodiment.
The high strength exhibited by the copper alloy material of the present invention means that the tensile strength is 500 MPa or more, preferably 650 MPa or more, more preferably 800 MPa or more.
The excellent bending workability exhibited by the copper alloy material of the present invention has the following meaning. That is, as a bending test, a BW (Bad Way: vertical direction of rolling) 90 ° bending is performed with a width w of the bending test piece being 10 mm and a bending R = 0 to 0.4 mm in 0.025 mm units. Whether the bending workability satisfies the following acceptance criteria corresponding to the level of tensile strength of the copper alloy material, with the ratio of the minimum bending radius (R) and thickness (t) at which cracks do not occur as R / t Evaluate by When the tensile strength is less than 800 MPa, R / t = 0.5 or less is accepted, when the tensile strength is 800 MPa or more and less than 900 MPa, R / t = 1.5 or less is accepted, and when the tensile strength is 900 MPa or more, R / t t = 2.0 or less is accepted.
The copper alloy material of the present invention has a high conductivity, preferably a conductivity of 35% IACS or more, more preferably 40% IACS or more, and more preferably 45% IACS or more.
First, the structure of the copper alloy material of the present invention having high strength, good bending workability, and high conductivity will be described.

  As a result of examining the mechanism in bending of a Corson-based copper alloy, the present inventors have confirmed that a shear band generated on the surface of the plate during bending is a cause of cracking. Further, the present inventors have found that this shear band can reduce the shear band and suppress the generation of cracks by increasing the Cube direction and the RDW direction. However, when the Cube orientation or RDW orientation is increased alone, the crystal grains of the Cube orientation or RDW orientation preferentially grow, the crystal grains become coarse, and the tensile strength and 0.2% proof stress decrease. I also found a point. In addition, since the Cube orientation and the RDW orientation have a small work hardening coefficient at the time of deformation, deformation occurs at a relatively low strength, and when these orientations are increased alone, the strength is also a problem.

  As a result of diligent research on a Corson alloy that has good bendability without reducing strength, we found that it is possible to achieve both strength and bending workability by simultaneously increasing the Cube orientation and RDW orientation to a predetermined range. The present invention has been completed. This makes it possible to have both higher strength and better bending workability than conventional Corson alloys.

(Gathering organization)
In particular, the texture of the copper alloy material of the present invention is an area ratio in which the deviation angle from the Cube orientation is 10 ° or less as a result of measurement from the ND direction by the SEM-EBSD method in order to achieve both strength and bending workability. Is a texture in which the area ratio of crystal grains having a deviation angle of 10 ° or less from the RDW orientation is 10% or more.
A preferable range of the area ratio of the region where the deviation angle from the Cube orientation is 10 ° or less is 12 to 45%, and a more preferable range is 15 to 30%. A preferable range of the area ratio of the region where the deviation angle from the RDW orientation is 10 ° or less is 12 to 45%, and a more preferable range is 15 to 30%.

  In the case of a copper alloy plate, a texture called a Cube orientation, a Goss orientation, a Brass orientation, a Copper orientation, an S orientation or the like is mainly formed as shown below, and there are crystal planes corresponding to them.

  The formation of these textures differs depending on the processing and heat treatment methods even in the case of the same crystal system. In the case of a texture of a plate material by rolling, it is represented by a plane and a direction, the plane is represented by {ABC}, and the direction is represented by <DEF>. The crystal orientation display method in this specification uses 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 surface normal direction (ND) is the Z axis. Using the index (hkl) of the crystal plane perpendicular to the Z axis (parallel to the rolling surface) and the index [uvw] of the crystal direction parallel to the X axis (perpendicular to the rolling surface) in each region in the material It is shown in the form of (hkl) [uvw]. 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], It uses {h k l} <u v w> using the parenthesis symbol. With the above notation, each direction is expressed as follows.

Cube orientation {001} <100>
RDW orientation {210} <100>
Goss orientation {011} <100>
Rotated-Goss orientation {011} <011>
Brass orientation {011} <211>
Copper orientation {112} <111>
S orientation {123} <634>
P direction {011} <111>

  In the texture of a normal copper alloy plate, when the composition ratio of these crystal planes changes, the elastic behavior of the plate material changes, and the workability such as bending changes.

  When the texture of the conventional Corson-based high-strength copper alloy plate is manufactured by a normal method, the S orientation {123} <634> and the Brass orientation {011} <211> are mainly used, and the ratio of the Cube orientation is reduced. The present inventors have confirmed that this is done. For this reason, in particular, in BW bending, a shear band is easily generated and bending workability is deteriorated. On the other hand, the present inventors have also confirmed that there is a problem that the strength is lowered when the integration of the Cube orientation and the RDW orientation is increased to improve the bendability.

  Therefore, the texture of the copper alloy material of the present invention is an aggregate having excellent strength and bendability in which the area ratio of the crystal grains of the Cube orientation {001} <100> and the RDW orientation {420} <100> is 10% or more respectively. It shall have an organization. However, in the present invention, if the area ratios of the crystal grains of the Cube orientation and the RDW orientation are both 10% or more, other orientations are allowed to exist as sub-azimuths.

  Cube orientation {001} <100> and RDW orientation {420} <100> orientation grain accumulation measurement of the texture of the copper alloy plate is based on the data obtained by measuring the electron microscopic structure by SEM using EBSD. Obtained by orientation analysis using the crystal orientation distribution function (ODF). Here, a sample area of 600 μm square containing 400 or more crystal grains was scanned in a 0.5 μm step, and the orientation was analyzed. Since these orientation distributions change in the plate thickness direction, it is preferable to obtain them by taking an average for some points in the plate thickness direction.

  This SEM-EBSD method is an abbreviation for Scanning Electron Microscopy-Electron Back Scattered Diffraction Pattern Method. That is, an electron beam is irradiated to individual crystal grains appearing on the SEM screen, and individual crystal orientations are identified from the diffracted electrons.

In the present invention, the area of the crystal grain having each texture orientation component of the RD-Rotated-Cube (RDW) orientation and the Cube (W) orientation and the atomic plane thereof is within the range of the predetermined deviation angle described below. It is specified by whether or not there is.
Regarding the deviation angle from the ideal orientation indicated by the index, (i) the crystal orientation of each measurement point and (ii) the RDW or Cube orientation as the ideal orientation to be considered are (i) and (ii) The rotation angle was calculated around a common rotation axis, and the deviation angle was calculated. For example, with respect to the S orientation (2 3 1) [6 -4 3], (1 2 1) [1 -1 1] is rotated by 19.4 ° with the (20 10 17) direction as the rotation axis. This angle is defined as a deviation angle. The common rotation axis is three integers of 40 or less, and the one that can be expressed by the smallest angle among them is adopted. This deviation angle is calculated for all measurement points and the first decimal place is an effective number, and the crystal has an azimuth of 10 ° or less from the deviation angle of the RDW orientation or 10 ° or less from the deviation angle of the Cube orientation. The area of the grains was divided by the total measurement area to obtain the area ratio of the atomic plane in each orientation.

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.
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 a colloidal silica abrasive after mechanical polishing. The measurement was performed from the plate surface.

(Component composition of copper alloy material)
Next, the reason for limiting the chemical composition in the copper alloy material of the present invention, which is a precondition for increasing the strength and having good bending workability even in bending, will be described (all the content% described is mass). %).

(Ni: 0.5-5.0%)
Ni is an element that is contained together with Si to be described later, forms a Ni ₂ Si phase precipitated by aging treatment, and contributes to improving the strength of the copper alloy material. If the content of Ni is too small, the Ni 2 _Si phase is insufficient, it is impossible to increase the tensile strength of the copper alloy material. On the other hand, when there is too much content of Ni, electrical conductivity will fall. Moreover, hot rolling workability deteriorates. Therefore, the Ni content is in the range of 0.5 to 5.0%, preferably 1.5 to 4.0%.

(Co: 0.5-5.0%)
Co is an element that is contained together with Si and contributes to improving the strength of the copper alloy material by forming a Co ₂ Si phase precipitated by aging treatment. When the content of Co is too small, the Co ₂ Si phase is insufficient, and the tensile strength of the copper alloy material cannot be increased. On the other hand, when there is too much content of Co, electrical conductivity will fall. Moreover, hot rolling workability deteriorates. Therefore, the Co content is in the range of 0.5 to 5.0%, preferably 0.8 to 3.0%.

These Ni and Co may contain both, but the total content thereof is 0.5 to 5.0%. When both Ni and Co are contained, both Ni ₂ Si and Co ₂ Si precipitate during the aging treatment, and the aging strength can be increased. When the total of these contents is too small, the tensile strength cannot be increased, and when it is too large, the conductivity and hot rolling processability are lowered. Therefore, the total content of Ni and Co is in the range of 0.5 to 5.0%, preferably in the range of 0.8 to 4.0%.

(Si)
Si is contained together with the Ni and Co, and forms a Ni ₂ Si or Co ₂ Si phase precipitated by aging treatment, thereby contributing to an improvement in the strength of the copper alloy material. The Si content is 0.2 to 1.5%, preferably 0.2 to 1.0%. The balance between conductivity and strength is best when the Si content is stoichiometrically Ni / Si = 4.2 and Co / Si = 4.2. Therefore, the Si content is preferably Ni / Si, Co / Si, and (Ni + Co) / Si in the range of 3.2 to 5.2, more preferably 3.5 to 4.8. is there.

When the Si is excessively contained outside this range, the tensile strength of the copper alloy material can be increased, but the excess amount of Si is dissolved in the copper matrix, and the conductivity of the copper alloy material is increased. Decreases. Moreover, when Si is contained excessively, the castability in casting, the hot and cold rolling processes are also reduced, and casting cracks and rolling cracks are likely to occur. On the other hand, if it is out of this range and the Si content is too small, the precipitated phase of Ni ₂ Si or Co ₂ Si is insufficient and the tensile strength of the material cannot be increased.

(Cr)
In addition to the above composition, Cr may be contained in an amount of 0.01 to 0.5 mass%. Cr has an effect of refining crystal grains in the alloy, and contributes to improvement of the strength and bending workability of the copper alloy material. If the amount is too small, the effect is small. If the amount is too large, a crystallized product is formed during casting, and the aging strength is lowered.

(Other alloy elements)
In addition to the above basic composition, the copper alloy material of the present invention includes, as an additive element, mass%, Sn: 0.05 to 1.0%, Zn: 0.01 to 1.0%, Ag: 0.01 to 1.0%, Mn: 0.01 to 1.0%, Zr: 0.1 to 1.0%, Mg: 0.01 to 1.0%, or a total of 0.01 to 1.0% It may be contained as needed in an amount of 1.0%. All of these elements have a common effect of improving any of the high strength, electrical conductivity, or good bending workability that the copper alloy material of the present invention is intended to achieve, or in addition to or in place of this. Furthermore, it is an element that improves other properties (such as stress relaxation resistance). Below, the characteristic effect of each element and the significance of the content range are described.

(Sn)
Sn is an element mainly improving the strength of the copper alloy material, and is selectively contained when used for applications in which these characteristics are important. When there is too little content of Sn, the strength improvement effect will be small. On the other hand, when Sn is contained, the electrical conductivity of the copper alloy material is lowered. In particular, if there is too much Sn, it will be difficult to make the conductivity of the copper alloy material 20% IACS or more. Therefore, when it contains, content of Sn shall be 0.01 to 1.0% of range.

(Zn)
Addition of Zn can improve the heat-resistant peelability and migration resistance of the solder. The effect is small when there is too little content of Zn. On the other hand, if Zn is contained, the electrical conductivity of the copper alloy material is lowered, and if there is too much Zn, it becomes difficult to make the electrical conductivity of the copper alloy material 20% IACS or more. Therefore, the Zn content is in the range of 0.01 to 1.0%.

(Ag)
Ag contributes to an increase in strength. If the content of Ag is too small, the effect is small. On the other hand, even if Ag is contained in excess of 1.0%, the effect is only saturated. Therefore, when it contains, content of Ag shall be 0.01 to 1.0% of range.

(Mn)
Mn mainly improves the workability in hot rolling. If the Mn content is too small, the effect is small. On the other hand, when there is too much Mn, the hot water flow property at the time of ingot-making of a copper alloy will deteriorate, and ingot-making yield will fall. Therefore, when it contains, the content of Mn is made 0.01 to 1.0% of range.

(Zr)
Zr mainly refines the crystal grains to improve the strength and bending workability of the copper alloy material. If the Zr content is too small, the effect is small. On the other hand, when there is too much Zr, a compound will be formed and workability, such as rolling of a copper alloy material, will fall. Therefore, when it contains, content of Zr shall be 0.01 to 1.0% of range.

(Mg)
Mg improves stress relaxation resistance. Therefore, when the stress relaxation resistance is required, it is selectively contained in the range of 0.01 to 1.0%. When the amount is too small, the added effect is small, and when the amount is too large, the electrical conductivity decreases.
Note that Mg, Sn, and Zn are all added to Cu—Ni—Si, Cu—Ni—Co—Si, and Cu—Co—Si copper alloys to improve the stress relaxation resistance. The stress relaxation resistance is further improved by a synergistic effect when each of them is added together than when they are added alone. In addition, there is an effect of remarkably improving solder embrittlement.

(Production conditions)
Next, preferable production conditions for the copper alloy material of the present invention will be described below. The copper alloy material of the present invention is manufactured through, for example, the steps of casting, hot rolling, cold rolling 1, intermediate annealing, cold rolling 2, solution heat treatment, aging heat treatment, finish cold rolling, and low temperature annealing. Is done. The copper alloy material of the present invention can be manufactured with almost the same equipment as a conventional Corson alloy. In order to obtain a predetermined texture, it is necessary to appropriately adjust the manufacturing conditions in each step. In this regard, the copper alloy material of the present invention is manufactured by performing at least one of treatment or processing under a predetermined condition, either a treatment after hot rolling, a cold rolling before solution treatment, or an intermediate annealing. be able to.

  Casting is performed by casting a molten copper alloy whose components are adjusted to the above composition range. Then, after chamfering the ingot, heating or homogenizing heat treatment is performed at 800 to 1000 ° C. and then hot rolling is performed. Here, in a normal method for producing a Corson alloy, it is rapidly cooled by a method such as water cooling immediately after hot rolling. On the other hand, in the first preferred embodiment of the method for producing a copper alloy material of the present invention, rapid cooling is not performed in order to increase the number of crystal grains having a (100) orientation in the RD direction after hot rolling. To do. The cooling rate at the time of slow cooling is preferably 5 K / second or less. Crystal grains having a (100) orientation in the RD direction cause a recovery phenomenon at a lower temperature than other orientations, and the area of the {h k l} <100> orientation in the hot rolled structure when analyzed from the ND direction. The rate can be increased. When the orientation grains having {h k l} <100> are increased in this hot rolled structure, the orientation of the Cube orientation {001} <100> or RDW {420} <100> is obtained in the subsequent solution treatment step. The area ratio of the crystal grains having can be increased. Since the structure does not change when the temperature at the time of cooling is less than 350 ° C., after the temperature is cooled to less than 350 ° C., it may be rapidly cooled by a method such as water cooling in order to shorten the production time.

  Next, after the hot rolling and cooling are completed, the surface is chamfered and cold rolling 1 is performed. If the rolling rate of the cold rolling 1 is too low, the Brass orientation, the S orientation, and the like develop even if the final product is manufactured thereafter, and it becomes difficult to increase the area ratio of the Cube orientation and the RDW orientation. Therefore, the rolling rate of the cold rolling 1 is preferably 70% or more.

  After cold rolling 1, intermediate annealing is performed at 300 to 800 ° C. for 5 seconds to 2 hours. After the intermediate annealing, cold rolling 2 with a rolling rate of 5 to 50% is performed. When this intermediate annealing and cold rolling 2 are repeated, the Cube orientation and the area ratio of RDW can be further increased. Therefore, in a second preferred embodiment of the method for producing a copper alloy material of the present invention, the intermediate annealing and the cold rolling 2 are repeated twice or more. Here, since an intensity | strength will fall when a crystal grain coarsens too much, it is preferable not to make a crystal grain coarsen to 20 micrometers or more. If the cold rolling rate after the intermediate annealing is too low, the crystal grains become coarse, so it is preferable to perform cold rolling at a rolling rate of 5 to 50% or more.

  The solution treatment is performed at 600 to 1000 ° C. for 5 to 300 seconds. Since necessary temperature conditions vary depending on the Ni and Co concentrations, it is necessary to select appropriate temperature conditions according to the Ni and Co concentrations. If the solution temperature is too low, the strength is insufficient in the aging treatment step, and if the solution temperature is too high, the material softens more than necessary and shape control becomes difficult.

  The aging treatment is performed at 400 to 600 ° C. for 0.5 to 8 hours. Since necessary temperature conditions vary depending on the Ni and Co concentrations, it is necessary to select appropriate temperature conditions according to the Ni and Co concentrations. When the temperature of the aging treatment is too low, the amount of aging precipitation is lowered and the strength is insufficient. Moreover, when the temperature of an aging treatment is too high, a precipitate will coarsen and intensity | strength will fall.

  The processing rate of finish cold rolling after the solution treatment is preferably 50% or less. By appropriately regulating the processing rate in this way, it is possible to suppress the azimuth rotation of the Cube azimuth and RDW azimuth to the Brass, S, Copper azimuth, etc., and achieve the texture state defined in the present invention. it can.

  The low temperature annealing is performed at 300 to 700 ° C. for 2 seconds to 5 hours. This annealing causes rearrangement of dislocations and changes to a more thermally stable atomic arrangement, thereby improving the stress relaxation resistance.

  In a more preferable manufacturing method for obtaining the copper alloy material of the present invention, the steps of both the first embodiment and the second embodiment are performed, that is, until a temperature range of at least less than 350 ° C. is obtained after hot rolling. Is not rapid quenching but slow cooling (preferably at a cooling rate of 5 K / sec or less), and intermediate annealing and cold rolling 2 are repeated twice or more.

  In order to ensure that the copper alloy material of the present invention produced by the above method has a predetermined property, it is sufficient to verify whether the structure of the copper alloy material is within a specified range by EBSD analysis.

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

  Copper alloy plates were produced by casting copper alloys having the compositions shown in Tables 1 and 2 below, and properties such as strength, electrical conductivity, and bending workability were evaluated.

First, it cast by DC (Direct Chill) method, and obtained the ingot of thickness 30mm, width 100mm, and length 150mm. Next, these ingots were heated to 950 ° C., held at this temperature for 1 hour, hot-rolled to a thickness of 14 mm, gradually cooled at a cooling rate of 1 K / second, and cooled to water at 300 ° C. or lower. Next, both surfaces were chamfered by 2 mm or more to remove the oxide film, and then cold rolling 1 with a rolling rate of 90 to 95% was performed. After that, cold rolling 2 was performed at 350 to 700 ° C. for 30 minutes with an intermediate annealing and a cold rolling rate of 10 to 30%. Thereafter, solution treatment was performed at 700 to 950 ° C. under various conditions for 5 seconds to 10 minutes, and immediately cooled at a cooling rate of 15 K / second or more. Next, an aging treatment was performed at 400 to 600 ° C. for 2 hours in an inert gas atmosphere, and then finish rolling with a rolling rate of 20% or less was performed, so that the final plate thickness was adjusted to 0.2 mm. After the finish rolling, low temperature annealing was performed at 400 ° C. for 30 seconds to obtain copper alloy sheet materials having various alloy compositions.
In addition, regarding Comparative Examples 9 to 12 in Table 2, the rolling rate is 60% or more in the temperature range of 700 ° C. or more and 950 ° C. or less and the rolling rate in the temperature range of 400 ° C. or more and less than 700 ° C. in the above hot rolling. 40% or more, without performing intermediate annealing after 85% or more of cold rolling, a solution heat treatment is performed to reach a temperature of 700 to 850 ° C. in a temperature rising time of 100 to 700 ° C. within 20 seconds. Then, intermediate rolling at a rolling rate of 0 to 50%, followed by aging precipitation heat treatment at 400 to 500 ° C., finish rolling at a rolling rate of 0 to 40%, and low temperature annealing at 150 to 550 ° C. were performed.

  With respect to the copper alloy plate thus manufactured, in each example, a sample cut out from the copper alloy plate subjected to the low-temperature annealing treatment was used, and the following tests and evaluations were performed.

(1) Area ratio of each crystal orientation grain About the structure of the copper alloy plate sample, the area ratio of the crystal grains of the Cube orientation and the RDW orientation when the EBSD analysis was performed from the ND direction was determined as follows. The measurement was performed by the EBSD method in a measurement area of about 600 μm square under the condition that the scan step was 0.5 μm. The measurement area was adjusted based on the inclusion of 400 or more crystal grains. As described above, for the atomic plane of a crystal grain having a deviation angle of 10 ° or less from each ideal orientation, the area of the atomic plane having each orientation is obtained, and the crystal grain in each orientation is divided by the total measurement area The area ratio was obtained. Here, the crystal grains having a deviation angle of 10 ° or less from the Cube orientation and a deviation angle of 10 ° or less from the RDW orientation were set to the same orientation.

(2) Tensile strength Tensile strength was determined in accordance with JIS Z 2241 by cutting out No. 5 test piece described in JIS Z 2201 from each specimen. The tensile strength is shown rounded to an integral multiple of 5 MPa.
(3) Electrical conductivity Electrical conductivity was determined according to JIS H 0505.
(4) Bending workability The bending work test is performed by performing a BW (Bad Way: vertical direction of rolling) 90 ° bending with a width w of a bending test piece of 10 mm and a bending R = 0 to 0.4 mm in 0.025 mm units. went. Bending workability was evaluated by setting the ratio of the minimum bending radius (R) and thickness (t) at which no cracks occurred to R / t. The acceptance criteria were as follows according to the level of tensile strength of the test material. When the tensile strength is less than 800 MPa, R / t = 0.5 or less is accepted, when the tensile strength is 800 MPa or more and less than 900 MPa, R / t = 1.5 or less is accepted, and when the tensile strength is 900 MPa or more, R / t t = 2.0 or less was accepted.
These results are shown in Tables 1 and 2.

  Table 1 shows examples of the present invention. In Examples 1 to 31, the texture was within the range of the present invention, and the tensile strength, conductivity, and bending workability were all excellent.

  Table 2 shows a comparative example for the present invention. Comparative Examples 1, 2, and 5 were inferior in tensile strength because the contents of Ni and / or Co and the content of Si were less than the scope of the present invention. In Comparative Examples 3, 4, 6, and 7, production was stopped because the content of Ni and / or Co was large and cracking occurred during hot rolling. In Comparative Example 8, the conductivity was inferior because the amount of Si added was too large. Comparative Examples 2-2 and 2-3 are examples using the same ingot as in Example 2. Comparative Example 2-2 is an example in which water cooling is performed immediately after hot rolling, intermediate annealing and cold rolling 2 are omitted, and the others are produced in the same manner as in Example 2. However, the area ratio of the Cube orientation and the RDW The area ratio was low, and the bending workability was remarkably inferior compared with the examples of the present invention. Comparative Example 2-3 is an example prepared in the same manner as in Example 2 except that water cooling is performed immediately after hot rolling, but the area ratio of RDW does not satisfy the scope of the present invention, and bending workability is improved. It was greatly inferior to the examples. Comparative Examples 9 to 12 had a low cube orientation area ratio and were inferior in bending workability.

  Table 3 shows another embodiment.

Examples 10-2, 18-2, and 25-2 were water-cooled immediately after hot rolling using the same ingots as Examples 10, 18 and 25 of Table 1, respectively, and intermediate annealing and cold rolling 2 These are repeated twice, and the others are prepared in the same manner as in the examples of Table 1, and the characteristics are evaluated in the same manner. These have a high area ratio of crystal grains of Cube orientation and RDW orientation, are within the scope of the present invention, and are excellent in strength, bending workability, and electrical conductivity.
In Examples 10-3, 18-3, and 25-3, using the same ingot as each of Examples 10, 18, and 25 in Table 1, intermediate annealing and cold rolling 2 were repeated twice, and the others were This is an example in which each of the examples in Table 1 was produced in the same manner and each characteristic was similarly evaluated. These had particularly high area ratios in the Cube orientation and RDW orientation, were excellent in strength and conductivity, and exhibited particularly excellent bending workability.

Claims (4)

  A copper alloy material containing either 0.5 or 5.0% by mass of Ni or Co in total, 0.2 to 1.5% by mass of Si, and the balance being Cu and inevitable impurities An electrical and electronic component having high strength and excellent bending workability, characterized in that the area ratio of Cube orientation crystal grains is 10% or more and the area ratio of RDW orientation crystal grains is 10% or more Copper alloy material.   The total of either one or both of Ni and Co is 0.5 to 5.0% by mass, Si is 0.2 to 1.5% by mass, Cr is 0.01 to 0.5% by mass, The balance is a copper alloy material composed of Cu and inevitable impurities, wherein the area ratio of Cube orientation crystal grains is 10% or more, and the area ratio of RDW orientation crystal grains is 10% or more. Copper alloy material for electrical and electronic parts that is strong and has excellent bending workability.   The total of either one or both of Ni and Co is 0.5 to 5.0 mass%, Si is 0.2 to 1.5 mass%, one of Zn, Sn, Mg, Ag, Mn, and Zr, or A total of 0.01 to 1.0% by mass of two or more, each of which is a copper alloy material composed of Cu and inevitable impurities, the area ratio of Cube-oriented crystal grains is 10% or more, and A copper alloy material for electrical and electronic parts having high strength and excellent bending workability, wherein the area ratio of crystal grains of RDW orientation is 10% or more.   The total of either or both of Ni and Co is 0.5 to 5.0 mass%, Si is 0.2 to 1.5 mass%, Cr is 0.01 to 0.5 mass%, Zn, Sn, A copper alloy material containing one or more of Mg, Ag, Mn, and Zr in a total amount of 0.01 to 1.0% by mass, with the balance being Cu and inevitable impurities, and having a Cube orientation A copper alloy material for electrical and electronic parts having high strength and excellent bending workability, wherein the area ratio of crystal grains is 10% or more and the area ratio of crystal grains in the RDW orientation is 10% or more.