JP4809935B2 - Copper alloy sheet having low Young's modulus and method for producing the same - Google Patents

Description

  The present invention relates to a copper alloy sheet material having high strength and high electrical conductivity suitable as a material for electrical and electronic parts such as connectors, and having a low Young's modulus, and a method for producing the same.

  In recent years, with the development of the electronics industry, the wiring of various electric / electronic devices has become more complex and highly integrated, and accordingly, the opportunity to use copper alloys for electric / electronic parts is increasing. In particular, electrical and electronic parts such as connectors are required to have a narrow pitch, a low profile, high reliability, and low cost. Therefore, in order to satisfy these requirements, the copper alloy plate material used for electrical and electronic parts such as connectors is thinned and pressed into a complicated shape, so it has high strength and conductivity, and at the same time It is required to have excellent press formability.

  In order to use as a terminal, the tensile strength in the rolling direction (RD) is 500 MPa or more as the strength that does not deform with respect to insertion / extraction or bending, and the conductivity is 30% IACS in order to suppress the generation of Joule heat due to energization. The above is preferable.

  Conventionally, it has been required that the connector material is made small and the Young's modulus of the connector material is large so that a large stress can be obtained with a small displacement. However, the dimensional accuracy of the terminal itself has become strict, and management standards such as mold technology and press operation management, or variations in the thickness and residual stress of connector materials have become strict, resulting in an increase in cost. Therefore, recently, there has been a demand for a design that uses a connector material having a low Young's modulus and has a structure that allows a large displacement of the spring, and that can tolerate variation in dimensions. Therefore, it has been demanded that the Young's modulus in the rolling direction is 110 GPa or less, preferably 100 GPa or less.

  So far, brass, phosphor bronze and the like have been generally used as connector materials. For both brass and phosphor bronze, the Young's modulus in the rolling direction is about 110 to 120 GPa, which is smaller than that of pure copper, 128 GPa, and is widely used as a low Young's modulus material. However, these copper alloys have a conductivity of 30% IACS or less, have a low conductivity, and cannot be used as connectors for applications where a large current flows. Therefore, a Corson alloy having a medium conductivity has been attracting attention and its amount of use has increased. This Corson alloy has a Young's modulus of about 130 GPa, and in this respect, the connector material has a low Young's modulus. It has been demanded. In addition, some connector designers may design a connector with a bending deflection coefficient (longitudinal elastic modulus at the time of a bending test) instead of a Young's modulus, and a low bending deflection coefficient is required. In general, the Young's modulus represents the longitudinal elastic modulus under tensile stress, the bending deflection coefficient represents the longitudinal elastic modulus under complex compression and tension stresses during bending, and the Young's modulus and bending deflection coefficient values are Although it is different, if the Young's modulus is low, the bending deflection coefficient tends to be low.

  Low Young's modulus and low bending deflection coefficient can be achieved not only by adding zinc (Zn) or phosphorus (P) to copper, but also by controlling the crystal orientation. For example, as described in Patent Document 1 and Patent Document 2, when pure copper is subjected to heat treatment after rolling at a high processing rate and recrystallized, Cube orientation (100) <100 with respect to the rolling normal direction (ND) of the plate material. > Increases, the Young's modulus decreases, and the flexibility becomes good. However, in the Corson alloy, simply increasing the cold rolling rate before recrystallization does not increase the Cube orientation, and it is difficult to control the Young's modulus.

JP 55-55454 A Japanese Patent No. 3009383

  The present invention relates to a copper alloy sheet for electrical and electronic parts such as connectors that can simultaneously satisfy the high strength, high electrical conductivity, and low Young's modulus required for electrical and electronic parts materials such as connectors due to the development of the electronics industry. And its manufacturing method.

According to the present invention, the following means are provided.
(1) An alloy composition comprising 0.5 to 5.0 mass% of Ni or Co in total, or 0.2 to 1.5 mass% of Si, with the balance being Cu and inevitable impurities. A copper for electric and electronic parts, characterized by having a 0.2% proof stress in the rolling direction of 500 MPa or more, an electrical conductivity of 30% IACS or more, a Young's modulus of 110 GPa or less, and a bending deflection coefficient of 105 GPa or less. Alloy plate material.
(2) The electrical / electronic component according to (1), wherein the area ratio of the (100) plane facing in the rolling direction obtained by analyzing the copper alloy sheet using EBSD is 30% or more Copper alloy plate material.
(3) The area ratio of the (111) plane facing in the rolling direction obtained by analyzing using the EBSD of the copper alloy sheet is 15% or less, as described in (1) or (2) Copper alloy sheet for electrical and electronic parts.
(4) The copper alloy sheet for electrical / electronic parts according to any one of (1) to (3), further containing 0.05 to 0.5 mass% of Cr.
(5) Further, it contains 0.01 to 1.0% by mass in total of one or more selected from the group consisting of Zn, Sn, Mg, Ag, Mn and Zr (1) The copper alloy sheet for electric / electronic parts according to any one of to (4).
(6) The copper alloy sheet for electrical / electronic parts according to any one of (1) to (5), which is a connector material.
(7) A connector comprising the copper alloy sheet for electric / electronic parts according to any one of (1) to (6).

  The copper base alloy material according to the present invention or the copper alloy material obtained by the production method according to the present invention has higher strength and higher strength required for materials for electrical and electronic parts such as connectors as compared to conventional Corson alloys. It has a low Young's modulus without impairing electrical conductivity, and is suitable as a copper alloy material for electrical and electronic parts such as connectors.

A preferred embodiment of the copper alloy sheet material of the present invention will be described in detail. Here, the “copper alloy material” means a material obtained by processing a copper alloy material into a predetermined shape (for example, a plate, a strip, a foil, a bar, a wire, or the like). Among them, the plate material refers to a material having a specific thickness and stable in shape and having a spread in the surface direction, and in a broad sense, includes a strip material. Here, in the plate material, “material surface layer” means “plate surface layer”, and “material depth position” means “position in the plate thickness direction”. The thickness of the plate material is not particularly limited, but it is preferably 8 to 800 μm, and more preferably 50 to 70 μm, considering that the effects of the present invention are better manifested and suitable for practical applications.
Note that the copper alloy sheet of the present invention is characterized by the accumulation ratio of atomic planes in a predetermined direction of the rolled sheet. However, this copper alloy sheet may have the characteristics of the present invention as a copper alloy sheet. The shape of the copper alloy plate material is not limited to the plate material or the strip material, and in the present invention, the pipe material can be interpreted and handled as a plate material.
Regarding the copper alloy material of the present invention which is a precipitation type copper alloy material such as Corson type having a low Young's modulus and a low bending deflection coefficient (a typical shape is a plate material), first, its alloy composition and then its Describe your organization.

(Component composition of copper alloy material)
The reason for limiting the chemical component composition in the copper alloy material of the present invention, which is a premise for having high strength, will be described (all contents “%” described here are “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 it is desired to increase the conductivity, it is preferable to contain Co alone without containing Ni. 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%, and more preferably 1.1 to 1.7%.

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. If the total content is too small, the tensile strength cannot be increased. If the total content is too large, the electrical 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 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 and the hot and cold rolling processability are also lowered, 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, 0.05 to 0.5 mass% of Cr may be contained. 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: 0.01 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 can be contained as needed in an amount of 1.0%. Any of these elements has a common effect of improving either the high strength and electrical conductivity or low Young's modulus that the copper alloy material of the present invention intends to play, in addition to or instead of this, Further, 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, when there is too much Sn, it becomes difficult to make the electrical conductivity of the copper alloy material 30% 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, when Zn is contained, the electrical conductivity of the copper alloy material is lowered, and when there is too much Zn, it is difficult to make the electrical conductivity of the copper alloy material 30% 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 a large amount of Ag is contained, the strength increasing 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%. If the amount is too small, the added effect is small, and if the amount is too large, the electrical conductivity decreases. Therefore, when it contains, content of Mg shall be 0.01 to 1.0% of range.
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.

The conductivity realized by the copper alloy sheet of the present invention is 30% IACS or more, a preferred range is 35% IACS or more, and a more preferred range is 45% IACS or more. Although there is no particular upper limit, it is practical that it is 60% IACS or less.
Moreover, a preferable range as the 0.2% yield strength in the rolling direction realized by the copper alloy material of the present invention is 500 MPa or more, preferably 650 MPa or more, and more preferably 800 MPa or more. Although there is no upper limit in particular, it is practical that it is 1100 MPa or less.
The bending deflection coefficient is preferably 105 GPa or less, and more preferably 100 GPa or less. Although there is no particular lower limit, it is practical that it is 60 GPa or more.
The Young's modulus is 110 GPa or less, and more preferably 100 GPa or less. Although there is no particular lower limit, it is practical that it is 70 GPa or more.

(Gathering organization)
The texture of the copper alloy material of the present invention is an analysis result from the rolling direction (RD) by the SEM-EBSD method in order to realize a low Young's modulus and a low bending deflection coefficient. It is preferable to have a texture with an area ratio of 30% or more. Note that all crystal grains having an orientation in which the angle between the plate material rolling direction (RD) and the normal to the surface is 10 ° or less have a (100) surface facing the RD.

  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. The crystal orientation display method in this specification takes a rectangular coordinate system in which the rolling direction (RD) of the material is the X axis, the sheet width direction (TD) is the Y axis, and the rolling normal direction (ND) is the Z axis. Using the index (hkl) of the crystal plane 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 ( hkl) [uvw]. In addition, as for (1 3 2) [6 -4 3] and (2 3 1) [3 -4 6], etc. It uses {hkl} <uvw> as a parenthesis to represent. With the above notation, each direction is expressed as follows.

As typical crystal orientations found in FCC metals, components represented by the following indices are common.
Cube orientation {001} <100>
Rotated-Cube orientation {012} <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, the elastic behavior of the plate material changes when the composition ratio of these crystal faces changes.

  In copper alloys, it is known that the above-mentioned orientation appears. However, as a result of intensive studies, increasing the area ratio of the (100) plane facing the RD decreases the Young's modulus and the bending deflection coefficient. It was found to be particularly effective. The orientation component whose (100) plane faces the RD includes the above-mentioned Cube orientation, Rotated-Cube orientation, Goss orientation, and the like. When the texture of a conventional Corson-based high-strength copper alloy plate is manufactured by a known method, the S orientation {123} <634> or the Brass orientation {011} <211 other than the Cube orientation {001} <100>. The present inventors confirmed that the ratio of Cube orientation decreased, the Young's modulus and the bending deflection coefficient increased. In particular, when there are many (111) planes in the RD direction, it was confirmed that the Young's modulus and the bending deflection coefficient increase.

  Therefore, in the texture of the copper alloy plate of the present invention, the angle formed by the two vectors of the plane orientation (for example, the (100) plane normal) and the RD of the crystal planes facing the RD is 10 ° or less. The area ratio of the crystal plane is preferably 30% or more, and thereby, it can have a texture with a low Young's modulus and a low bending deflection coefficient. The area ratio of the (100) plane facing the RD is more preferably 40% or more, and more preferably 50% or more. If the area ratio of the (100) plane facing the RD is increased in this way, the Young's modulus can be made 110 GPa or less and the bending deflection coefficient can be made 105 GPa or less. This is because the area ratio of the crystal plane toward the RD having a low Young's modulus and a low bending deflection coefficient (100) increases. In addition, the Young's modulus can be lowered by decreasing the area ratio of the crystal plane facing the (111) RD having a high Young's modulus and bending deflection coefficient. The area ratio of the (111) plane facing the RD is preferably 15% or less, and more preferably 10% or less.

  Measurement of the area ratio of the (100) plane facing the RD in the texture of the copper alloy plate can be obtained by analyzing the electron microscope structure by SEM using EBSD. Here, a range including 400 or more crystal grains (for example, an 800 μm square sample area) was scanned in 1 μm steps, 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, each crystal grain appearing on the SEM screen is irradiated with an electron beam, and each crystal orientation is identified from the diffracted electrons.

The crystal orientation display method in the present specification takes a rectangular coordinate system in which the rolling direction (RD) of the material is the X axis, the sheet width direction (TD) is the Y axis, and the rolling normal direction (ND) is the Z axis. The ratio of the area where the (100) plane faces is defined by the area ratio. Calculate the angle of the angle between two vectors of (100) plane normal and RD of each crystal grain in the measurement region, and sum the areas for those having an atomic plane whose angle is 10 ° or less. The value obtained by dividing by the total measurement area was defined as the area ratio (%) of the region having an atomic plane in which the angle formed by the normal of the (100) plane and the RD was 10 ° or less.
That is, in the present invention, regarding the accumulation of atomic planes facing in the rolling direction (RD) of the rolled sheet, the region having an atomic plane whose angle formed by the normal of the (100) plane and the RD is 10 ° or less, The (100) plane itself, which is normal to the rolling direction (RD) of the rolled sheet, which is the ideal orientation, with respect to the accumulation of atomic planes facing the rolling direction (RD) of the rolled sheet, that is, facing the RD, and (100) plane Is a region (sum of these areas) in which the normal line of RD and each of the atomic planes whose angle formed by RD is 10 ° or less are combined. Hereinafter, these surfaces are collectively referred to as a (100) plane facing the RD, and these regions are also simply referred to as an atomic plane region facing the RD to the (100) plane. The same applies to the (111) plane facing the RD.

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

(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 includes, for example, steps of casting, hot rolling, gradual cooling, cold rolling 1, intermediate annealing, cold rolling 2, solution heat treatment, aging heat treatment, finish cold rolling, and low temperature annealing. It is manufactured through. 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 predetermined physical properties and further a texture, it is necessary to appropriately adjust the manufacturing conditions of each step. In this regard, the copper alloy material of the present invention is manufactured by performing processing or processing at least one of processing after hot rolling or cold rolling and intermediate annealing before solution treatment under predetermined conditions. Can do.

  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 the copper alloy material of the present invention, the method is characterized in that rapid cooling is not performed in order to increase the (100) plane facing the RD after hot rolling, but the cooling is performed slowly. And The cooling rate at the time of slow cooling is preferably 5 K / second or less. The orientation with the (100) plane facing the RD causes a recovery phenomenon at a lower temperature than the other orientations, and the area ratio of the orientation with the (100) plane facing the RD in the hot rolled structure can be increased. When the ratio of grains having an orientation in which the (100) plane faces the RD in this hot-rolled structure is increased, the area ratio of the orientation in which the (100) plane faces in the RD in the solution forming process, which is a subsequent process, is increased. 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, etc. develop even if the final product is manufactured thereafter, making it difficult to increase the (100) area ratio. 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 3 to 60% is performed. When this intermediate annealing and cold rolling 2 are repeated, the area ratio of the (100) plane facing RD 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.

  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, the crystal grains having the (100) orientation such as the Cube orientation are prevented from rotating to the Brass, S, Copper orientation, etc., and the physical properties of the obtained copper alloy material In addition, a preferable state of the texture can be achieved.

  Low temperature annealing is performed at 300 to 700 ° C. for 10 seconds to 2 hours. This annealing can improve the stress relaxation resistance and the spring limit value required for the connector material.

  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 verified by EBSD analysis whether the physical properties and further the texture of the copper alloy material are within a predetermined range. do it.

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

  A copper alloy plate was produced by casting a copper alloy having each composition shown in Tables 1 and 2 below, and properties such as strength (0.2% proof stress), conductivity, Young's modulus and the like 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., kept at this temperature for 1 hour, hot-rolled to a thickness of 14 mm, gradually cooled at a cooling rate of 1 K / s, and cooled to 300 ° C. or less with water. Next, both sides were chamfered 2 mm each 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 ° C./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 50% or less was performed, so that the final plate thickness was adjusted to 0.15 mm. After the finish rolling, a low temperature annealing treatment was performed at 400 ° C. for 30 seconds to obtain a copper alloy sheet having each alloy composition.

  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 crystal orientation grains For the structure of the copper alloy sheet sample, the area ratio of the (100) plane facing the RD was determined as follows.
That is, a crystal grain having a crystal orientation with an angle of 10 ° or less with respect to an angle formed by the normal of the (100) plane when the EBSD analysis is performed from the RD direction and the RD is a grain having a (100) plane facing the RD. . Specifically, the area ratio of the (100) plane facing the RD was determined as follows. By the EBSD method, measurement was performed in a sample measurement area of about 800 μm square under the condition that the scan step was 1 μm. The measurement area was adjusted based on the inclusion of 400 or more crystal grains. As described above, the sum of the areas of the (100) plane of the crystal grain having the normal line of the (100) plane such that the angle formed with the rolling direction (RD) of the plate material sample is 10 ° or less is obtained, By dividing the sum of the areas by the total measurement area, the area ratio (%) of the (100) plane facing the RD was obtained. Here, the crystal grains having an angle of 10 ° or less were set to the same orientation.
Moreover, it calculated | required similarly about the area ratio (%) of the (111) surface which faces RD.
(2) 0.2% proof stress 0.2% proof stress was obtained in accordance with JIS Z 2241 by cutting out No. 5 test piece described in JIS Z 2201 from each specimen. The 0.2% yield strength is shown rounded to an integer multiple of 5 MPa.
(3) Electrical conductivity Electrical conductivity was determined according to JIS H 0505.
(4) Young's modulus The Young's modulus was measured using a strain gauge with a tensile tester using a strip-shaped test piece with a width of 20 to 30 mm and a strength region of 0.2% proof stress or less. In addition, the test piece was extract | collected in parallel with respect to the rolling direction.
(5) Bending Deflection Coefficient The bending deflection coefficient was measured according to the Japan Copper and Brass Association (JCBA) technical standard. The width of the test piece was 10 mm, the length was 15 mm, a cantilever bending test was performed, and the deflection coefficient was measured from the load and deflection displacement.
These results are shown in Tables 1 and 2.

  Table 1 shows examples of the present invention. In Examples 1 to 29, the texture was within the preferred range of the present invention, and the 0.2% proof stress, conductivity, Young's modulus, and bending deflection coefficient were all excellent.

Table 2 shows a comparative example for the present invention. In Comparative Examples 1, 2, and 5, the Ni and / or Co content and the Si content were too much less than the scope of the present invention, so the 0.2% yield strength was inferior. In Comparative Examples 3, 4, 6, and 7, since the content of Ni and / or Co was too large, the production was stopped because cracks occurred during hot rolling. In Comparative Example 8, the conductivity was inferior because the Si concentration was too high.
The following comparative example is an example 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 manufactured in the same manner as in Example 2, but the (100) plane is suitable for RD. And the area ratio of the (111) plane was high, and the Young's modulus and bending deflection coefficient were higher than those of 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 the (100) plane facing the RD is low, and the Young's modulus is an example of the present invention. Higher than.

  Table 3 shows another embodiment.

Examples 10-2, 18-2, and 25-2 in Table 3 were water-cooled immediately after hot rolling using the same ingots as Examples 10, 18, and 25 in Table 1, respectively, and were subjected to intermediate annealing and cooling. This is an example in which the inter-rolling 2 was repeated twice, and the others were produced in the same manner as in the examples of Table 1 and the characteristics were evaluated in the same manner. These have an area ratio of the (100) plane facing the RD within the preferable range of the present invention, and are excellent in strength, electrical conductivity, Young's modulus, and bending deflection coefficient.
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 a particularly high area ratio of the (100) plane facing RD, a particularly low Young's modulus of 100 GPa or less, a particularly low bending deflection coefficient of 90 GPa, and excellent 0.2% proof stress and electrical conductivity. .

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

(Comparative Example 101) ... Conditions of JP2009-007666 A metal element similar to that of Invention Example 1-1 is blended, and an alloy composed of Cu and inevitable impurities is melted in a high-frequency melting furnace. This was cast at a cooling rate of 0.1 to 100 ° C./second to obtain an ingot. This was held at 900 to 1020 ° C. for 3 minutes to 10 hours, then hot worked, then water quenched, and chamfered to remove oxide scale. In the subsequent steps, the copper alloy c01 was manufactured by performing the processes of steps A-3 and B-3 described below.
The manufacturing process includes one or more solution heat treatments, and here, the process is classified before and after the last solution heat treatment, and the process up to the intermediate solution is A-3 process, It was set as B-3 process in the process after intermediate solution.

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

  The obtained specimen c01 differs from the above examples in terms of production conditions in the presence or absence of slow cooling to 350 ° C. after hot rolling, the area ratio of the (111) plane facing the RD is high, Young's modulus and bending As a result, the deflection coefficient did not meet the required characteristics.

(Comparative Example 102) ... Conditions of Japanese Patent Application Laid-Open No. 2006-283059 The copper alloy having the composition of Example 1-1 of the present invention was melted in the atmosphere under charcoal coating in an electric furnace to determine whether casting was possible. . The molten ingot was hot-rolled to a thickness of 15 mm. Subsequently, the hot rolled material is subjected to cold rolling and heat treatment (cold rolling 1 → solution annealing, cold rolling 2 → aging treatment → cold rolling 3 → short annealing) to a predetermined thickness. A copper alloy sheet (c02) was produced.

  The obtained specimen c02 differs from Example 1 above in terms of the production conditions with or without slow cooling to 350 ° C. after hot rolling, and with or without intermediate annealing and cold rolling before solution treatment. The area ratio of the (111) surface facing the surface was high, and the Young's modulus and bending deflection coefficient did not satisfy the requirements.

(Comparative Example 103) ... Conditions of Japanese Patent Application Laid-Open No. 2006-152392 The alloy having the composition of the present invention example 1-1 was melted under a charcoal coating in the atmosphere in a kryptor furnace and cast into a cast iron book mold. Thus, an ingot having a thickness of 50 mm, a width of 75 mm, and a length of 180 mm was obtained. Then, after chamfering the surface of the ingot, it was hot-rolled at a temperature of 950 ° C. until the thickness became 15 mm, and rapidly cooled into water from a temperature of 750 ° C. or higher. Next, after removing the oxide scale, cold rolling was performed to obtain a plate having a predetermined thickness.

  Subsequently, after using a salt bath furnace and performing a solution treatment by heating at a temperature for 20 seconds, the solution was rapidly cooled in water, and then cold-rolled sheets having various thicknesses were obtained by finish cold rolling in the latter half. At this time, as shown below, the cold-rolled sheet (c03) was obtained by variously changing the cold rolling processing rate (%). As shown below, these cold-rolled sheets were subjected to aging treatment at various temperatures (° C.) and times (hr).

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

  The obtained specimen c03 differs from the above Example 1 in terms of the production conditions with or without slow cooling to 350 ° C. after hot rolling, and with or without intermediate annealing and cold rolling before solution treatment. The area ratio of the (111) surface facing the surface was high, and the Young's modulus and bending deflection coefficient did not satisfy the requirements.

(Comparative Example 104) ... Conditions of JP-A-2008-223136 The copper alloy shown in Example 1 was melted and cast using a vertical continuous casting machine. A sample with a thickness of 50 mm was cut out from the obtained slab (thickness 180 mm), heated to 950 ° C., extracted, and hot rolling was started. At that time, the pass schedule was set so that the rolling rate in the temperature range of 950 to 700 ° C. was 60% or more and the rolling was performed in the temperature range of less than 700 ° C. The final pass temperature of hot rolling is between 600-400 ° C. The total hot rolling rate from the slab is about 90%. After hot rolling, the surface oxide layer was removed (faced) by mechanical polishing.

  Subsequently, after performing cold rolling, it used for the solution treatment. The temperature change during the solution treatment was monitored by a thermocouple attached to the sample surface, and the temperature raising time from 100 ° C. to 700 ° C. in the temperature raising process was determined. The ultimate temperature is adjusted within the range of 700 to 850 ° C. according to the alloy composition so that the average crystal grain size after solution treatment (the twin boundary is not regarded as a grain boundary) is 10 to 60 μm. The holding time in the temperature range of 850 ° C. was adjusted in the range of 10 sec to 10 mim. Subsequently, the plate material after the solution treatment was subjected to intermediate cold rolling at a rolling rate and then subjected to an aging treatment. The aging treatment temperature was adjusted to a material temperature of 450 ° C., and the aging time was adjusted to a time when the hardness peaked at 450 ° C. according to the alloy composition. The optimum solution treatment conditions and aging treatment time according to such an alloy composition have been grasped by preliminary experiments. Next, finish cold rolling was performed at a rolling rate. About what performed finish cold rolling, the low temperature annealing which puts it in a 400 degreeC furnace for 5 minutes after that was given after that. In this way, a test material c04 was obtained. If necessary, chamfering was performed in the middle, and the thickness of the specimen was adjusted to 0.2 mm. The main production conditions are described below.

[Conditions of JP-A-2008-223136 Example 1]
Hot rolling rate at less than 700 ° C to 400 ° C: 56% (1 pass)
Before solution treatment Cold rolling rate: 92%
Intermediate cold rolling Cold rolling rate: 20%
Finish cold rolling Cold rolling rate: 30%
Temperature rising time from 100 ° C to 700 ° C: 10 seconds

  The obtained specimen c04 differs from the above-mentioned Example 1 in terms of production conditions with or without slow cooling to 350 ° C. after hot rolling, and with or without intermediate annealing and cold rolling before solution treatment. The area ratio of the (111) surface facing the surface was high, and the Young's modulus and bending deflection coefficient did not satisfy the requirements.

Claims (7)

  It has an alloy composition containing 0.5 to 5.0 mass% of Ni or Co in total, or 0.2 to 1.5 mass% of Si, and the balance of Cu and inevitable impurities. A copper alloy sheet for electrical and electronic parts, characterized in that the 0.2% proof stress in the rolling direction is 500 MPa or more, the electrical conductivity is 30% IACS or more, the Young's modulus is 110 GPa or less, and the bending deflection coefficient is 105 GPa or less.   2. The copper alloy for electrical and electronic parts according to claim 1, wherein an area ratio of a (100) plane facing in a rolling direction obtained by analyzing the copper alloy sheet using EBSD is 30% or more. Board material.   3. The electric / electronic component according to claim 1, wherein an area ratio of a (111) plane facing in a rolling direction obtained by analyzing the copper alloy sheet using EBSD is 15% or less. Copper alloy sheet.   Furthermore, 0.05-0.5 mass% of Cr is contained, The copper alloy board | plate material for electrical / electronic components in any one of Claims 1-3 characterized by the above-mentioned.   Furthermore, 0.01-1.0 mass% in total containing 1 type, or 2 or more types chosen from the group which consists of Zn, Sn, Mg, Ag, Mn, and Zr is characterized by the above-mentioned The copper alloy sheet material for electrical / electronic parts according to any one of the above.   It is a material for connectors, The copper alloy board | plate material for electrical / electronic components of any one of Claims 1-5 characterized by the above-mentioned.   The connector which consists of a copper alloy board | plate material for electrical / electronic components of any one of Claims 1-6.