JPWO2020004034A1 - Copper alloy plate material, method for manufacturing copper alloy plate material, and connector using copper alloy plate material - Google Patents

Abstract

(EN) Provided are a copper alloy plate material excellent in press workability, a method for manufacturing the copper alloy plate material, and a connector using the copper alloy material. In a cross section 10 including the rolling parallel direction and the plate thickness direction, a quadrangular first region 11 partitioned by the rolling parallel direction dimension of 100 μm and the plate thickness dimension is further divided at intervals of 10 μm in the rolling parallel direction and the sheet thickness direction. Then, it is subdivided into a plurality of square second regions 12 having a size of 10 μm square, and out of the plurality of second regions 12 forming the first region 11, an outer second region 13 forming four sides of the first region 11. When the average value of KAM is measured by the electron backscattering diffraction method (EBSD) in each of the inner second regions 14 except for, the difference (Δθ) between the maximum value and the minimum value of the measured average values of KAM is 25°. The following copper alloy sheet 1.

Description

TECHNICAL FIELD The present invention relates to a copper alloy plate material having excellent press workability, which is used for a connector for electronic devices, a connector for automobile parts, and the like, a method for manufacturing the copper alloy plate material, and a connector formed using the copper alloy plate material.

BACKGROUND ART Copper alloy plate materials used for connectors for electronic devices, connectors for in-vehicle components, etc. are generally subjected to press working such as thickness reduction and punching. With the recent miniaturization of electronic devices and parts mounted on automobiles, the shape uniformity of pressed products has been required more and more.

It is known that the shape uniformity of the pressed product is influenced by the crystal grain size and the precipitation state of the copper alloy sheet material, and it has been attempted to improve the shape uniformity of the pressed product by controlling their microstructure. For example, in Patent Document 1, Co: 0.5 to 3.0 mass% and Si: 0.1 to 1.0 mass% are contained for the purpose of improving dimensional stability when pressed. A copper alloy for electronic materials, the balance of which is Cu and unavoidable impurities, 0.2% proof stress in the rolling parallel direction of 500 MPa or more, conductivity of 60% IACS or more, and an average crystal grain size in the rolling parallel cross section of 10 μm or less. Yes, X-ray diffraction integrated intensity I{200} from the {200} crystal plane, X-ray diffraction integrated intensity I{220} from the {220} crystal plane, and X-ray diffraction from the {311} crystal plane on the surface A technique is disclosed in which the integrated strength I{311} and the copper alloy for electronic materials satisfy the relationship of (I{220}+I{311})/I{200}≧5.0. However, it cannot be said that the press workability of the copper alloy sheet according to the related art, such as Patent Document 1, sufficiently satisfies the required characteristics of the market.

Note that Patent Documents 2 and 3 disclose a technique for improving the surface smoothness of the processed surface after etching by controlling the average KAM value in the crystal grains of the Cu—Ni—Si alloy. However, in these patent documents, only the KAM value itself in the crystal grain is focused on, and the variation (that is, strain distribution) of the KAM value in the entire copper alloy sheet and the crystal grain not only in the crystal grain The entire copper alloy sheet including boundaries and the like is not described, and the shape uniformity of the pressed product was insufficient.

Patent No. 6306632 Japanese Patent No. 6154565 Japanese Patent No. 6152212

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a copper alloy sheet having excellent press workability, a method for manufacturing the copper alloy sheet, and a connector using the copper alloy.

In the cross section including the rolling parallel direction and the plate thickness direction, the present inventors defined a rectangular first region defined by the rolling parallel direction dimension of 100 μm and the plate thickness dimension as 10 μm in the rolling parallel direction and the plate thickness direction. It is further divided at intervals and subdivided into a plurality of square second regions of 10 μm square, and out of the plurality of second regions forming the first region, an outer second region forming four sides of the first region is divided. When the average value of KAM is measured by electron backscatter diffraction (EBSD) in each of the removed inner second regions, the difference (Δθ) between the maximum value and the minimum value of KAM is 25° or less. By using an alloy sheet material, it was found that the variation in strain amount released with time after press punching was suppressed, and a copper alloy sheet material with excellent press workability was obtained, and the present invention was completed. It was In the present specification, “excellent in press workability” means that a press work product having a desired shape can be obtained. For example, the press work product obtained by press work is excellent in shape uniformity. Say that.

That is, the gist of the present invention is as follows.
(1) In a cross section including the rolling parallel direction and the plate thickness direction, a quadrangular first region partitioned by the rolling parallel direction dimension of 100 μm and the plate thickness dimension is further provided at intervals of 10 μm in the rolling parallel direction and the plate thickness direction. Of the plurality of second regions forming the first region, the outer second region forming four sides of the first region is divided into a plurality of square second regions of 10 μm square. When the average value of KAM is measured by electron backscatter diffraction (EBSD) in each of the removed inner second regions, the difference (Δθ) between the maximum value and the minimum value of the measured KAM average values is 25° or less. A copper alloy sheet material.

(2) The copper alloy sheet material according to (1), wherein the difference Δθ between the maximum value and the minimum value of the KAM average value is 4° or more and 20° or less.

(3) Co: 0.20 mass% or more and 2.00 mass% or less, Si: 0.05 mass% or more and 0.50 mass% or less, at least 1 selected from the group consisting of Sn, Zn, Mg, Mn, and Cr. Species: Total 0 mass% or more and 1.00 mass% or less, the mass ratio of Co to Si (Co/Si) is 2.5 or more and 5.0 or less, and the balance is copper and unavoidable impurities. The copper alloy sheet material according to (1) or (2), which has a component composition.

(4) The copper alloy material according to (3), which contains at least one selected from the group consisting of Sn, Zn, Mg, Mn, and Cr in a total amount of 0.01% by mass or more and 1.00% by mass or less.

(5) In a cross section including a Si compound containing Si and at least one element selected from the group consisting of Sn, Zn, Mg, Mn, Cr and Co, and including the rolling parallel direction and the plate thickness direction, The density D of the Si compound having a diameter L of 0.05 μm or more and 5 μm or less is 10 ³ pieces/mm ² or more and 10 ⁵ pieces/mm ² or less. (1) to (4) Copper alloy plate material.

(6) In the cross section including the rolling parallel direction and the plate thickness direction, the crystal grain size has a rolling parallel direction dimension (r _(RD) ) of 3 μm or more and 35 μm or less and a plate thickness direction dimension (r _(ND) ) of 1 μm. The copper alloy plate material according to any one of (1) to (5) having a thickness of 15 μm or less.

(7) The ratio (Ra _(RD) /Ra _(TD) ) of the arithmetic mean roughness Ra _{(RD) in} the rolling parallel direction to the arithmetic mean roughness Ra _(TD) in the direction perpendicular to the rolling on the surface of the copper alloy sheet is , 0.5 or more and 2.0 or less, the copper alloy sheet material according to any one of (1) to (6).

(8) The copper alloy plate material according to any one of (1) to (7), which is a copper alloy plate material for a connector.

(9) A connector formed using the copper alloy plate material according to any one of (1) to (8).

(10) The method for producing a copper alloy sheet material according to any one of (1) to (8), wherein the copper alloy material is cast [step 1], homogenized heat treatment [step 2], chamfered [ Step 5], cold rolling [Step 6], intermediate heat treatment [Step 10], finish cold rolling [Step 12], and temper annealing [Step 13] are performed in this order, and the cold rolling [Step 6] The roll diameter φ of the rolling mill is 50 mm or more and 200 mm or less, the rolling rate R of the finish cold rolling [step 12] is 5% or more and 30% or less, and the annealing temperature in the temper annealing [step 13] is T (° C.), where F (N/mm ² ) is the applied tension in the rolling parallel direction, the annealing temperature (T) is 200° C. or higher and 400° C. or lower, and the applied rolling parallel direction is The tensile strength (F) of the copper alloy plate material satisfying the following formula (1) in relation to the annealing temperature.
−0.1×T+45≦F≦−0.1×T+80 (1)

The copper alloy sheet material of the present invention has Δθ of 25° or less and suppresses the variation in the amount of strain released over time after performing press working such as press punching, and thus is excellent in press workability. Therefore, by using the copper alloy sheet material of the present invention, it is possible to obtain a pressed product with high shape uniformity. Further, the copper alloy sheet material of the present invention can also have high tensile strength. Therefore, the copper alloy plate material of the present invention is suitable as a copper alloy plate material for a connector such as a connector for electronic equipment or a connector for a vehicle-mounted part.

It is a figure explaining the measuring method of (DELTA)(theta) in this invention. It is a figure which shows the relationship between the annealing temperature T and tension F of temper annealing in this invention. It is a schematic diagram which looked at the sample obtained by press punching from the above.

Specific embodiments (hereinafter, referred to as “this embodiment”) will be described in detail with reference to the drawings. The present invention is not limited to the following embodiments, and various modifications can be made without changing the gist of the present invention.

In the cross section including the rolling parallel direction and the plate thickness direction, the copper alloy sheet material according to the present embodiment has a rectangular first region defined by the rolling parallel dimension of 100 μm and the sheet thickness dimension as the rolling parallel direction. It is further divided in the plate thickness direction at intervals of 10 μm and subdivided into a plurality of square second regions of 10 μm square, and among the plurality of second regions forming the first region, four sides of the first region are formed. When the average value of KAM is measured by electron backscatter diffraction (EBSD) in each of the inner second regions excluding the outer second region, the difference Δθ between the maximum value and the minimum value of the measured KAM average values (hereinafter It is a copper alloy sheet having a value of 25° or less).

The EBSD method is a crystal orientation analysis technique that utilizes backscattered electron Kikuchi line diffraction that occurs when a sample is irradiated with an electron beam in a scanning electron microscope (SEM). The information obtained in the analysis of crystal grains by EBSD includes information up to a depth of several tens nm where the electron beam penetrates the sample.

Further, KAM is an average value of crystal orientation differences between a measurement point and all its adjacent measurement points. The KAM value has a correlation with the dislocation density and corresponds to the lattice strain amount of the crystal, which is also described in Patent Document 3 and the like.

In the present embodiment, Δθ is limited to 25° or less. In other words, in the present embodiment, the uneven distribution of the internal strain of the copper alloy plate material as a whole is suppressed and made uniform. As a result, it is possible to suppress variations in the amount of strain that is released with time after performing press working such as press punching on the copper alloy sheet. Therefore, the press workability is improved, and particularly the press punching workability is excellent. For example, the pin pitch variation of the press work product obtained by the press punching process is suppressed, and the shape uniformity of the obtained press work product is improved. To do.

On the other hand, when Δθ is larger than 25°, there is a large deviation in the distribution state of the KAM value of the copper alloy sheet material, which means that the distribution of strain amount is also uneven. When the copper alloy sheet is pressed, the strain is released after the pressing, but if there is a large deviation in the distribution of the KAM value before the pressing and there is a deviation in the strain distribution, the copper alloy sheet is pressed. After that, a large difference occurs in the amount of strain released with time. If there is a difference in the amount of strain released, the uniformity of the shape of the pressed product obtained by pressing will be impaired. For example, it appears as a variation in the pitch interval of the pressed product.

In addition, the copper alloy sheet materials manufactured by the conventional methods such as Patent Documents 2 and 3 do not control the distribution of internal strain of the entire copper alloy sheet material at all, and therefore the variation of the released strain amount. As a result, pressed products have large variations in shape, and press workability cannot be said to sufficiently satisfy market needs. Further, even if the KAM value itself in the crystal grain is made small, the press workability is insufficient because the grain boundary is not taken into consideration.

Δθ is preferably 4° or more and 20° or less from the viewpoint that the press workability can be further improved.

In the present embodiment, the average value of KAM measured by EBSD in each of the inner second regions 14 is not particularly limited, and may be the same as the value of a normal copper alloy sheet material. For example, it is 4° or more and 40° or less, more preferably 6° or more and 30° or less.

In the present embodiment, as will be described in detail later, processing such as cold rolling, manufacturing conditions such as annealing temperature in temper annealing, tension in the rolling parallel direction, and the like, and the component composition and the like are specified, Preferably, Δθ can be set to 25° or less, further 4° or more and 20° or less by controlling the crystal grain size, the precipitate size, the precipitate density, and the surface roughness.

Δθ is obtained by the following method.
[How to obtain Δθ]
FIG. 1 is a diagram for explaining a method of measuring Δθ in the present invention, FIG. 1(a) is a perspective view of a copper alloy plate material 1, and FIG. 1(b) is a first region 11 of FIG. 1(a). FIG.
First, as shown in FIG. 1A, a cross section 10 of the copper alloy sheet 1 including the rolling parallel direction and the sheet thickness direction, that is, the copper alloy sheet 1 is cut along a plane including the rolling parallel direction and the sheet thickness direction. In the cross section 10 obtained in this manner, a rectangular area (cross section indicated by diagonal lines in FIG. 1) defined by the rolling parallel dimension of 100 μm and the plate thickness dimension is defined as a first area 11.
Next, as shown in FIG. 1(b), the first region 11 is further divided into 10 μm square-shaped second regions 12 each having 10 μm intervals in the rolling parallel direction and the plate thickness direction. Subdivide.
Of the plurality of second regions 12, those forming the four sides of the first region 11 are referred to as outer second regions 13, and regions excluding the outer second regions 13 are referred to as inner second regions 14. FIG. 1B shows an example in which the first region 11 is composed of 32 outer second regions 13 forming four sides of the first region 11 and 48 inner second regions 14. ing.
Then, with respect to each inner second region 14, an average value of KAM (Kernel Average Misorientation) values is measured at a pitch of 0.1 μm by an electron backscatter diffraction method (EBSD).
The difference between the maximum value and the minimum value among the measured average values of KAM in each inner second region 14 is Δθ.
In addition, when the first region 11 is divided into the second regions 12 and a small piece region whose dimension (length) in the plate thickness direction is less than 10 μm occurs at the end in the plate thickness direction, The small area is excluded and is not treated as the first area 11 or the second area. That is, when the first region 11 is divided and subdivided into the second regions 12, a small piece region whose dimension in the plate thickness direction is less than 10 μm occurs at the end in the plate thickness direction, for example, a copper alloy A multiple of 10 μm in each of the vertical direction from the center of the plate material 1 in the plate thickness direction is defined as the first region 11, and the small piece regions less than 10 μm generated at both ends in the plate thickness direction are not treated as the first region 11. To do.

<Ingredient composition>
The copper alloy sheet material according to the present embodiment is, for example, a Cu—Co—Si system, Co: 0.20 mass% or more and 2.00 mass% or less, Si: 0.05 mass% or more and 0.50 mass% or less. , Sn, Zn, Mg, Mn, and Cr at least one kind: a total of 0 mass% or more and 1.00 mass% or less, and a mass ratio of Co to Si (Co/Si) is 2 It is 0.5 or more and 5.0 or less, and the balance has a composition of copper and inevitable impurities. Hereinafter, each component of the Cu-Co-Si system will be described.

(1) Cu-Co-Si system [Co component]
The Co content is 0.20 mass% or more and 2.00 mass% or less. When the Co content is less than 0.20% by mass or more than 2.00% by mass, Δθ becomes larger than 25° and the press workability becomes poor. Further, when the Co content is less than 0.20 mass %, sufficient strength cannot be obtained, the sagging of the pressed product becomes large, and the shape of the pressed product deteriorates. The sagging refers to a portion where the upper surface side of the press cut surface of the pressed product is roundly deformed, and is caused by poor maintenance of the press machine or reduction in strength of the press material. The sagging causes deterioration of the spring characteristics of small connectors and the like, and deteriorates the basic characteristics. Further, when the Co content is more than 2.00 mass %, Co cannot be dissolved as a solid solution during the solution heat treatment and does not contribute to the strengthening of the copper alloy. Would also increase the cost of the copper alloy sheet. Therefore, the Co content is preferably 0.60 mass% or more and 2.00 mass% or less, and more preferably 0.70 mass% or more and 2.00 mass% or less.

[Si component]
The Si content is 0.05% by mass or more and 0.50% by mass or less. When the Si content is less than 0.05% by mass or more than 0.50% by mass, Δθ becomes larger than 25° and the press workability deteriorates. Further, when the Si content is less than 0.05 mass %, the strength of the copper alloy cannot be obtained similarly to Co, the sagging of the pressed product becomes large, and the shape deteriorates. When the Si content is more than 0.50 mass%, the conductivity is lowered. The Si content is preferably 0.10% by mass or more and 0.45% by mass or less.

[Mass ratio of Co to Si (Co/Si)]
The mass ratio of Co to Si (Co/Si) is 2.5 or more and 5.0 or less. When the mass ratio Co/Si is less than 2.5 or larger than 5.0, Δθ becomes larger than 25° and the press workability becomes poor. Further, when the mass ratio Co/Si is less than 2.5, Si is excessively solid-solved with Co in the solution heat treatment and remains in the matrix even after precipitation by the aging heat treatment. As a result, the conductivity increases and the conductivity decreases. When the mass ratio Co/Si is larger than 5.0, Co is excessively solid-dissolved in Si in the solution heat treatment, and the conductivity also decreases after the aging heat treatment. The mass ratio Co/Si is preferably 2.5 or more and 4.5 or less, more preferably 2.6 or more and 4.4 or less.

[Sn, Zn, Mg, Mn, Cr]
The Cu-Co-Si-based copper alloy plate material of the present invention contains Co and Si described above as indispensable contained components, but at least selected from the group consisting of Sn, Zn, Mg, Mn and Cr, if necessary. One kind may be contained as an optional additive component in a range of 1.00 mass% or less in total. The content of at least one selected from the group consisting of Sn, Zn, Mg, Mn, and Cr is preferably 0.01% by mass or more and 1.00% by mass or less, more preferably 0.02% by mass or more, It is 1.00 mass% or less.
Addition of at least one of Sn, Zn, Mg, Mn, and Cr has the effect of increasing the tensile strength, reducing the sagging of the pressed product, and improving the press workability. However, when the total content of at least one of Sn, Zn, Mg, Mn, and Cr is more than 1.00 mass %, Δθ becomes larger than 25° and the press workability becomes poor. Further, since these elements hinder the movement of dislocations, the release of strain after pressing is hindered. As a result, it is assumed that the shape of the pressed product varies due to the non-uniform strain distribution.

[Inevitable impurities]
The unavoidable impurities mean impurities at a content level that can be unavoidably included in the manufacturing process. Examples of the unavoidable impurities include Bi, Se, As, Ag and the like. The content of the unavoidable impurities is, for example, 0.10 mass% or less in terms of the total amount of the unavoidable impurity components.

Although the component composition for the Cu—Co—Si system has been described above, in the present embodiment, a component composition other than the Cu—Co—Si system may be used as long as Δθ satisfies the predetermined range. .. Below, Cu-Ni-Si system, phosphor bronze system, and titanium copper system, which are component compositions other than Cu-Co-Si system, will be explained.

(2) Cu-Ni-Si system In Cu-Ni-Si system, Ni: 2.00 mass% or more and 4.30 mass% or less, Si: 0.10 mass% or more and 0.90 mass% or less, Sn, Zn , Mg, Mn, and Cr, at least one selected from the group consisting of: 0 mass% or more and 1.00 mass% or less, with the balance being copper and inevitable impurities.

[Ni component]
The content of Ni is 2.00 mass% or more and 4.30 mass% or less. When the Ni content is less than 2.00% by mass or more than 4.30% by mass, Δθ becomes larger than 25° and the press workability becomes poor. Further, if the Ni content is less than 2.00 mass %, sufficient material strength cannot be obtained, and if it is 4.30 mass% or more, the contribution to the material strength is small.

[Si component]
In the Cu-Ni-Si system, the Si content is 0.10 mass% or more and 0.90 mass% or less. When the Si content is less than 0.10% by mass or more than 0.90% by mass, Δθ becomes larger than 25° and the press workability becomes poor.

[Sn, Zn, Mg, Mn, Cr]
The Cu-Ni-Si-based copper alloy plate material of the present invention contains Ni and Si described above as essential components, but at least selected from the group consisting of Sn, Zn, Mg, Mn, and Cr, if necessary. One kind may be contained as an optional additive component in a range of 1.00 mass% or less in total. The content of at least one selected from the group consisting of Sn, Zn, Mg, Mn, and Cr is preferably 0.01 mass% or more and 1.00 mass% or less, and more preferably 0.02 mass% or more. , 1.00 mass% or less.

Addition of Sn, Zn, Mg, Mn or Cr has the effect of increasing the tensile strength, reducing the sagging of the pressed product, and improving the press workability. However, when the total content of Sn, Zn, Mg, Mn, and Cr is more than 1.00 mass %, Δθ becomes large. Further, since these elements hinder the movement of dislocations, the release of strain after pressing is hindered. As a result, the strain distribution becomes non-uniform, resulting in variations in the shape of the pressed product. Further, when the total content of Sn, Zn, Mg, and Mn is less than 0.01% by mass, the effect of increasing the strength cannot be obtained and does not contribute to the improvement of press workability.

The unavoidable impurities are the same as in the Cu-Co-Si system.

(3) Phosphor bronze (Cu-Sn) system Phosphor bronze contains Sn: 0.05% by mass or more and 1.00% by mass or less, P: 0.01% by mass or more and 0.45% by mass or less, and the balance. It has a component composition consisting of copper and inevitable impurities.

[Sn component]
The content of Sn is 0.05% by mass or more and 1.00% by mass or less. When the Sn content is more than 1.00% by mass, it is not preferable because it inhibits the release of strain after press working.

[P component]
The content of P is 0.01% by mass or more and 0.45% by mass or less.

The unavoidable impurities are the same as in the Cu-Co-Si system.

(4) Titanium Copper (Cu-Ti) System Titanium copper has a composition in which Ti: 1.00 mass% or more and 3.00 mass% or less is contained, and the balance is copper and inevitable impurities.

[Ti component]
The content of Ti is 1.00 mass% or more and 3.00 mass% or less. At higher concentrations, the contribution to material strength is small.

The unavoidable impurities are the same as in the Cu-Co-Si system.

<About organization>
[Diameter and Density of Si Compound]
The copper alloy sheet material of the present embodiment preferably contains a Si compound containing Si. In the Cu-Co-Si system, the Si compound contained in the copper alloy sheet material is a Si compound containing Si and at least one element selected from the group consisting of Sn, Zn, Mg, Mn, Cr and Co. It is preferable to have. Further, in the Cu-Ni-Si system, the Si compound contained in the copper alloy sheet material contains Ni, at least one element selected from the group consisting of Sn, Zn, Mg, Mn, and Cr, and Si. It is preferably a Si compound.

Then, in the cross section including the rolling parallel direction and the plate thickness direction (the cross section including the rolling parallel direction and the plate thickness direction used in the above KAM value), the Si compound having a diameter L of 0.05 μm or more and 5 μm or less The density D of the compound is preferably 10 ³ pieces/mm ² or more and 10 ⁵ pieces/mm ² or less.

When the diameter L of the Si compound is 0.05 μm or more and 5 μm or less, press workability can be further improved. If the diameter L is less than 0.05 μm, the effect of improving press workability is small, and if the diameter L exceeds 5 μm, the contribution of the Si compound to both material strengthening and pressability improvement is very small.

When the density D of the Si compound having a diameter L of 0.05 μm or more and 5 μm or less is 10 ³ pieces/mm ² or more and 10 ⁵ pieces/mm ² or less, press workability and tensile strength are compatible at a high level. You can If the density D of the Si compound having a diameter L of 0.05 μm or more and 5 μm or less is less than 10 ³ pieces/mm ^{2, the} number of crack initiation points at the time of press punching is small, so that the press workability is improved. Is small. When the density D of the Si compound having a diameter L of 0.05 μm or more and 5 μm or less exceeds 10 ⁵ pieces/mm ² , the diameter L that has a relatively small contribution to the strength is smaller than that of the Si compound having a diameter L of less than 0.05 μm. The Si compound having a thickness of 0.05 μm or more and 5 μm or less tends to occupy a large proportion of the whole, so that the strength cannot be increased and the properties required for the product cannot be obtained. The density D of the Si compound having a diameter L of 0.05 μm or more and 5 μm or less is preferably 5×10 ³ pieces/mm ² or more and 5×10 ⁴ pieces/mm ² or less.

[Crystal grain size]
In the cross section including the rolling parallel direction and the plate thickness direction (cross section including the rolling parallel direction and the plate thickness direction used in the above KAM value), the copper alloy sheet material of the present embodiment has a crystal grain size in the rolling parallel direction dimension ( It is preferable that r _(RD) ) is 3 μm or more and 35 μm or less, and the plate thickness direction dimension (r _(ND) ) is 1 μm or more and 15 μm or less. When the crystal grain size is less than 3 μm in the rolling parallel direction (r _(RD) ) or less than 1 μm in the plate thickness direction (r _(ND) ), it is necessary to lower the temperature in the solution heat treatment, and Co Si cannot be sufficiently dissolved as a solid solution, and the amount of precipitation is reduced in the subsequent aging heat treatment, which may reduce the strength of the copper alloy sheet. On the other hand, when the grain size in the rolling parallel direction (r _(RD) ) is greater than 35 μm or the dimension in the plate thickness direction (r _(ND) ) is greater than 15 μm, the strength decreases and sagging during press working occurs. Tends to be larger. The crystal grain size is preferably 5 μm or more and 33 μm or less in the rolling parallel direction dimension (r _(RD) ) and 2 μm or more and 14 μm or less in the plate thickness direction dimension (r _(ND) ).
In addition, it is preferable that the dimension (r _(RD) ) in the rolling parallel direction is larger than the dimension r _{(ND) in the} plate thickness direction.

[Surface roughness]
Ratio (Ra _(RD) /Ra _{(TD) )} of the arithmetic mean roughness Ra _{(RD) in} the rolling parallel direction to the arithmetic mean roughness Ra _(TD) in the direction perpendicular to the rolling on the surface of the copper alloy sheet material of the present embodiment. ) Is preferably 0.5 or more and 2.0 or less. When the Ra _(RD) /Ra _(TD) ratio is 0.5 or more and 2.0 or less, the strain distribution in the rolling parallel direction and the rolling vertical direction can be made more uniform, and the shape of the pressed product can be made uniform. It is possible to improve the sex. The amount of strain introduced during rolling is larger in the convex portions and concave portions on the surface of the copper alloy plate material, and unevenness occurs, so the Ra _(RD) /Ra _(TD) ratio is controlled within the above range. Therefore, it is preferable to make the amount of strain uniform. The Ra _(RD) /Ra _(TD) ratio is more preferably 0.6 or more and 1.9 or less.

[Copper alloy plate thickness]
The form of the copper alloy plate material of the present embodiment is not particularly limited, and examples thereof include a copper alloy plate and a copper alloy strip. The plate thickness of the copper alloy plate material is preferably 0.03 mm to 0.6 mm, for example. The copper alloy plate material having a plate thickness of 0.03 mm to 0.6 mm particularly exerts the effect in the present embodiment, and, for example, the effect of suppressing the press pitch variation due to the uniform strain distribution appears remarkably.

[Tensile strength of copper alloy sheet]
The copper alloy sheet material of the present embodiment can have high tensile strength, and for example, the tensile strength TS can be 400 MPa or more, further 500 MPa or more, and more preferably 600 MPa or more.

<About manufacturing method>
In the method for manufacturing a copper alloy sheet according to the present embodiment, a copper alloy material having the composition of the copper alloy sheet is cast [step 1], homogenized heat treatment [step 2], chamfered [step 5], Cold rolling [step 6], intermediate heat treatment [step 10], finish cold rolling [step 12], and temper annealing [step 13] are performed in this order, and the roll diameter of the rolling mill for cold rolling [step 6] is performed. φ is 50 mm or more and 200 mm or less, the rolling work rate R of finish cold rolling [step 12] is 5% or more and 30% or less, and the annealing temperature in temper annealing [step 13] is T (° C.). When the tension in the rolling direction is F (N/mm ² ), the annealing temperature (T) is 200° C. or higher and 400° C. or lower, and the applied tension (F) in the rolling direction is the same as the annealing temperature. It can be manufactured by a manufacturing method satisfying the following formula (1). On the other hand, with the manufacturing method that does not satisfy the above conditions, the copper alloy sheet material according to the present embodiment cannot be manufactured.
−0.1×T+45≦F≦−0.1×T+80 (1)

For example, casting [step 1], homogenization heat treatment [step 2], hot rolling [step 3], cooling [step 4], chamfering [step 5], cold rolling [step 6], solution heat treatment [step] 7], cooling [step 8], cold rolling [step 9], intermediate heat treatment [step 10], aging heat treatment [step 11], finish cold rolling [step 12], temper annealing [step 13] in this order. Give. Each step will be described below.

Casting [Process 1]
In the casting step [step 1], a raw material (copper alloy material) of a copper alloy plate material such as Cu and Si is melted and cast in a casting machine (inner wall) preferably made of carbon, for example, a graphite crucible. The atmosphere inside the casting machine during melting is preferably vacuum or an inert gas atmosphere such as nitrogen or argon in order to prevent the formation of oxides. The casting method is not particularly limited, and for example, a horizontal continuous casting machine or an upcast method can be used.

Homogenization heat treatment [Process 2]
Since solidification segregation and crystallized substances generated at the time of ingot in the casting [step 1] are coarse, in the homogenizing heat treatment step [step 2], the solidification is made as small as possible by forming a solid solution in the matrix phase and eliminated as much as possible. Specifically, for example, the homogenized heat treatment is performed at a temperature of 800 to 1000° C. for 1 to 24 hours in an inert gas or the like.

Hot rolling [Process 3]
In the hot rolling [step 3], for example, rolling is performed at a processing temperature of about 850° C. to 1000° C. so as to obtain a desired plate thickness. The hot working is not limited to rolling or extrusion. The hot rolling [step 3] after the homogenizing heat treatment can be omitted.

Cooling [Step 4]
In the cooling step [step 4], the hot-rolled copper alloy sheet material is cooled. It is preferable to cool immediately after hot rolling. The cooling [step 4] can be omitted if the hot rolling [step 3] is not performed.

Chamfering [Process 5]
In the chamfering step [step 5], the oxide film and the altered layer on the skin of the copper alloy sheet are removed. It can be performed by a generally known method, for example, mechanical polishing.

Cold rolling [Process 6]
In the present embodiment, the roll diameter (diameter) φ of the rolling mill used in cold rolling [step 6] is 50 mm or more and 200 mm or less. When the roll diameter φ is less than 50 mm, the biting angle at the time of rolling becomes small, the amount of rolling oil introduced becomes small, the oil film may break, and seizure may occur on the roll material, resulting in reduced productivity. I will end up. On the other hand, when the roll diameter φ is larger than 200 mm, conversely, the biting angle is large, the amount of rolling oil introduced increases, the roll roughness becomes difficult to be transferred, and the surface roughness of the copper alloy sheet cannot be controlled appropriately. As a result, oil pits are generated and the surface becomes rough, resulting in a non-uniform strain distribution in the finish cold rolling [step 12] in the subsequent stage.

In the cold rolling [step 6], cold rolling with a rolling work rate of, for example, 30 to 99% is performed. In the present specification, the rolling rate is a value obtained by the following formula.
Rolling rate (%)=(plate thickness before rolling (mm)-plate thickness after rolling (mm))/plate thickness before rolling (mm)×100

Solution heat treatment [Process 7]
In the solution heat treatment step [Step 7], the solution heat treatment is performed by setting an appropriate solution temperature condition according to the concentration of the contained element. The solution temperature is, for example, 650 to 1000°C. The solution heat treatment [step 7] can be omitted.

Cooling [Process 8]
In the cooling step, the solution heat treated copper alloy sheet material is cooled. It is preferable to cool immediately after the solution heat treatment. The cooling [step 8] can be omitted if the solution heat treatment [step 7] is not performed.

Cold rolling [Process 9]
In the cold rolling, cold rolling is performed at a rolling rate of 1.0 to 90%, for example. The second cold rolling can be omitted.

Intermediate heat treatment [Process 10]
In the intermediate heat treatment [Step 10], for example, by performing heat treatment at a temperature lower than the solution heat treatment temperature, it is possible to obtain a partially recrystallized subannealed structure without completely recrystallizing the material. The intermediate heat treatment is performed at 20° C. to 500° C. for 0.5 to 2 hours, for example.

Aging heat treatment [Process 11]
In the aging heat treatment [step 11], for example, the aging heat treatment is performed at 400° C. to 500° C. for 1 to 3 hours. The aging heat treatment [Step 11] can be omitted.

Finish cold rolling [Process 12]
In the present embodiment, in the finish cold rolling [step 12], cold rolling with a rolling work ratio R of 5% or more and 30% or less is performed. When the rolling rate R is less than 5%, sufficient material strength cannot be obtained, and when the rolling rate R is more than 30%, the increase in the strengthening of the copper alloy is slowed down even if it is further processed, and the time required for the rolling step is reduced. It becomes long and only the manufacturing cost rises. The rolling rate R in finish cold rolling is a value obtained by the following formula.
Rolling rate R (%) = (plate thickness before rolling (mm)-plate thickness after rolling (mm))/plate thickness before rolling (mm) x 100

Tempering annealing [Process 13]
In the present embodiment, when the annealing temperature in temper annealing is T (° C.) and the applied tension in the rolling parallel direction is F (N/mm ² ), the annealing temperature (T) is 200° C. or higher and 400° C. or higher. The tension (F) in the rolling parallel direction, which is equal to or lower than 0° C., satisfies the following formula (1) in relation to the annealing temperature. That is, as shown in FIG. 2, which is a diagram showing the relationship between the annealing temperature T and the tension F of the temper annealing in the present embodiment, the formula of F=−0.1×T+45 which is the left side of the formula (1). In the region surrounded by the lower straight line representing the above, the upper straight line representing F=−0.1×T+80, which is the right side of the formula (1), and the dotted line representing the temperature range. 13] is performed.
−0.1×T+45≦F≦−0.1×T+80 (1)

When the annealing temperature T is lower than 200°C, the elongation of the copper alloy is impaired and workability deteriorates, and when it is higher than 400°C, the material softens.

Then, the higher the annealing temperature T, and especially the higher the tension F, the more the release of strain is promoted, which affects Δθ. Therefore, in order to obtain the copper alloy sheet material of the present embodiment, the formula (1) is satisfied. As described above, it is necessary to control the tension F with respect to the annealing temperature T in an appropriate balance.

Here, although the tension F in the rolling parallel direction applied in the temper annealing has not been studied in detail in the related art, the tension F has been found to have an effect in the present invention. Based on this knowledge, an experiment was performed in which the annealing temperature T of the temper annealing [step 13] and the tension F at that time were variously changed, and the relationship of the formula (1) was derived. In order to obtain the copper alloy sheet material of the present embodiment, it is necessary to control so as to satisfy the expression (1). For example, when the tension F is less than −0.1×T+45, the amount of released strain is small, and the effect of equalizing the strain distribution cannot be exhibited. On the other hand, when the tension F is larger than −0.1×T+80, the strain in the rolling parallel direction is likely to be released due to the increase in the tension in the rolling direction, and the strain amount in the rolling parallel direction becomes smaller than that in the rolling vertical direction. Uniformity is reduced.

<Applications of copper alloy sheet materials>
The copper alloy plate material according to the present embodiment is excellent in press workability such as press punching property, and for example, it is necessary to form a connector for electronic equipment or a connector for automobile vehicle parts having excellent pin shape uniformity. You can

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

[Examples 1 to 20 and Comparative Examples 1 to 19]
The alloy components shown in Tables 1 and 2 were melted in a high-frequency melting furnace in the atmosphere and cast [Step 1] to obtain an ingot having a thickness of 30 mm, a width of 100 mm and a length of 150 mm. Next, it is heated at 1000° C. for 1 hour in an inert gas atmosphere, and immediately after being subjected to homogenizing heat treatment [step 2], hot rolling [step 3] is performed to obtain a plate thickness of 0.3 mm and immediately followed by cooling [step 4]. ]did. Then, chamfering [step 5] and cold rolling [step 6] were performed to obtain 0.1 to 0.2 mm. Then, immediately after the solution heat treatment [step 7] at 700° C. to 950° C., cooling is performed [step 8], cold rolling [step 9], and intermediate heat treatment at 20° C. to 500° C. for 1 hour [step 10]. , Aging heat treatment at 400° C. to 500° C. for 2 hours [step 11], finish cold rolling [step 12], and temper annealing [step 13] in this order to obtain a copper alloy sheet with a thickness of 0.100 mm. Obtained. In the aging heat treatment [Step 11], the temperature was set so that the strength was the highest. In Example 18 and Comparative Example 17, hot rolling [step 3], cooling [step 4], solution heat treatment [step 7], cooling [step 8] and aging heat treatment [step 11] were not performed. .. In each of Examples 1 to 20 and Comparative Examples 1 to 19, the roll diameter φ of the rolling mill used in the cold rolling [step 6], the rolling rate R in the finish cold rolling [step 12], and the temper annealing [step]. 13], temperature T and tension F in the rolling direction are shown in Tables 3 and 4.

Regarding the obtained copper alloy sheet material, Δθ, density L of Si compound having diameter L of 0.05 μm or more and 5 μm or less, crystal grain size (rolling parallel direction dimension (r _(RD) ), sheet thickness direction dimension (r _(ND)) )), the arithmetic mean roughness Ra and the tensile strength TS on the surface of the copper alloy sheet and the press punching workability were evaluated by the following methods. The results are shown in Tables 5 and 6.

[Δθ]
According to the above [Method of obtaining Δθ], Δθ was obtained using SEM-EBSD (JSM-7001FA manufactured by JEOL Ltd.). The results are shown in Tables 5 and 6. The analysis software OIM Analysis (trade name) manufactured by TSL was used to analyze the EBSD measurement data.

[Measurement of density D of Si compound having diameter L of 0.05 to 5 μm]
In a cross section including the rolling parallel direction and the plate thickness direction, a rolling parallel direction dimension of 100 μm and a rectangular region (the first region 11 used in the above KAM value) having a plate thickness dimension (100 μm in the example) are SEM ( The average value of the longest straight line and the shortest straight line connecting the two outer edges of each Si compound observed from the obtained secondary electron image is defined as the diameter L of each Si compound by observing with a Scanning Electron Microscope). Then, the density D (pieces/mm ² ) was calculated from the number of Si compounds having a diameter L of 0.05 μm or more and 5 μm or less. The results are shown in the “Density D of Si compound” column in Tables 5 and 6. In addition, the Si compound was judged by EDX attached to the SEM depending on whether Si is contained as a constituent element.

[Measurement of crystal grain size (dimension (r _(RD) ) in the rolling parallel direction, grain size direction (r _(ND) )) of the crystal grain boundary in the cross section 10]
The cross section 10 including the rolling parallel direction and the plate thickness direction (the cross section including the rolling parallel direction and the plate thickness direction used in the above KAM value) was acid-etched to facilitate observation of crystal grain boundaries with an optical microscope, and then an optical microscope was used. Photographs were taken at 500 times at any three locations. From the photograph, the crystal grain size was measured in the rolling parallel direction and the plate thickness direction (rolling vertical direction) based on the crystal grain size measuring method (cutting method) specified in JIS H0501-1986.

[Measurement of Arithmetic Average Roughness Ra on Surface of Copper Alloy Sheet (Arithmetic Average Roughness Ra _(RD) in Rolling Parallel Direction, Arithmetic Average Roughness Ra _(TD) in Rolling Right Direction)]
The arithmetic mean roughness Ra on the surface of the copper alloy sheet was calculated according to JIS B0601-1994 using a surf coder SGA31 manufactured by Kosaka Laboratory Ltd. The measurement conditions were a cutoff value of 0.8 mm, a reference length of 0.8 mm, an evaluation length of 4.0 mm, a measurement speed of 0.1 mm/s, and a stylus tip radius of 2 μm. Tables 5 and 6 show the ratio Ra _(RD) /Ra _(TD) of the arithmetic mean roughness on the surface.

[Evaluation of press punching workability (evaluation of press pitch variation)]
Press punching was performed on the obtained copper alloy sheet material to evaluate the press punching workability. The press punching method and the press punching workability evaluation method will be described with reference to FIG.

FIG. 3 is a schematic view of a sample (press-processed product) obtained by press-punching, viewed from above, and FIG. 3A shows an ideal sample after press-punching without variations in pin pitch. 3(b) shows a state in which the pin pitch varies. Then, as shown in FIG. 3, the tip spacing of the pins and the pin ^d T [mm], the root gap ^d B [mm], the pin length L [mm], the pin width is W [mm], press punching V, which is an index showing the variation in pitch, is defined by the following formula.
V=|100−(d ^T /d ^B )×100|/L

The press punching process has a clearance of 6%, and when the shape of the pressed material is an ideal sample with no variation in the pin pitch, d ^T =d ^B =0.4 mm, L=1.0 mm, W= A mold having a size of 0.3 mm was used.

In the sample obtained by press punching, 100,000 consecutive Vs of adjacent pins were calculated, the ratio at which V was 10 [mm ⁻¹ ] or less was obtained, and the pitch variation was evaluated according to the following criteria. ⊚ indicates that there are few pitch variations, and x indicates that there are many pitch variations.
◎: 95% to 100% ◯: 90% to less than 95% ×: less than 90%

[Tensile strength]
Three test pieces of No. 13B of JIS Z2241 cut out from the direction parallel to the rolling of the test piece were measured according to JIS Z2241, and the average values thereof are shown in Tables 5 and 6.

As shown in Table 1 and Table 2, Examples 1 to 14 and Comparative Examples 1 to 14 are Cu-Co-Si-based, Examples 15 to 17 and Comparative Examples 15 to 16 are Cu-Ni-Si-based, and Examples. 18 and Comparative Example 17 are Cu-Sn based, and Examples 19 to 20 and Comparative Examples 18 to 19 are Cu-Ti based.
In Examples 1 to 20 in which the component composition and the manufacturing conditions were within the above-described predetermined ranges and Δθ was 25° or less, the pitch variation was small and the press punching workability was excellent. Then, among the Cu-Co-Si-based Examples 1 to 14, Examples 2, 6, 7, 10 and 11 satisfying Δθ of 4° or more and 20° or less are evaluated as ⊚, and particularly press punching is performed. It was excellent. In the examples other than the Cu-Co-Si system, even if Δθ satisfies 4° or more and 20° or less, the evaluation is ◯, and the degree of influence of Δθ and the like on the pitch variation depends on the alloy system. It was different.
On the other hand, in Comparative Examples 1 to 14 in which the component composition and manufacturing conditions were out of the predetermined ranges and Δθ was larger than 25°, the pitch variation was large and the press punching workability was poor.

1 Copper Alloy Sheet Material 10 Cross Section Including Rolling Parallel Direction and Plate Thickness Direction of Copper Alloy Sheet Material 11 First Region 12 Second Region 13 Outer Second Region 14 Inner Second Region

Claims (10)

In the cross section including the rolling parallel direction and the plate thickness direction,
A square first region defined by a rolling parallel dimension of 100 μm and a plate thickness dimension is further divided at intervals of 10 μm in the rolling parallel direction and the plate thickness direction to form a plurality of square second regions of 10 μm square. Electron backscattering diffraction method in each of the inner second regions excluding the outer second regions forming the four sides of the first region among the plurality of second regions that are subdivided into A copper alloy sheet material having a difference (Δθ) between the maximum and minimum values of the measured KAM average of 25° or less when the average KAM is measured by (EBSD). The copper alloy plate material according to claim 1, wherein a difference Δθ between the maximum value and the minimum value of the KAM is 4° or more and 20° or less. Co: 0.20 mass% or more and 2.00 mass% or less, Si: 0.05 mass% or more and 0.50 mass% or less, at least one selected from the group consisting of Sn, Zn, Mg, Mn, and Cr: total. A component composition containing 0 mass% or more and 1.00 mass% or less, a mass ratio of Co to Si (Co/Si) of 2.5 or more and 5.0 or less, and the balance being copper and inevitable impurities. The copper alloy plate material according to claim 1 or 2. The copper alloy material according to claim 3, containing at least one selected from the group consisting of Sn, Zn, Mg, Mn, and Cr in a total amount of 0.01% by mass or more and 1.00% by mass or less. A Si compound containing at least one element selected from the group consisting of Sn, Zn, Mg, Mn, Cr and Co, and Si,
In a cross section including the rolling parallel direction and the plate thickness direction, the density D of the Si compound having a diameter L of 0.05 μm or more and 5 μm or less is 10 ³ pieces/mm ² or more and 10 ⁵ pieces/mm ² or less. The copper alloy plate material according to any one of 1 to 4. In the cross section including the rolling parallel direction and the plate thickness direction, the crystal grain size has a rolling parallel direction dimension (r _(RD) ) of 3 μm or more and 35 μm or less and a sheet thickness direction dimension (r _(ND) ) of 1 μm or more and 15 μm or less. The copper alloy sheet material according to any one of claims 1 to 5. The ratio (Ra _(RD) /Ra _(TD) ) of the arithmetic mean roughness Ra _{(RD) in} the rolling parallel direction to the arithmetic mean roughness Ra _(TD) in the direction perpendicular to the rolling on the surface of the copper alloy sheet is 0. It is 5 or more and 2.0 or less, The copper alloy plate material of any one of Claims 1-6. The copper alloy plate material according to any one of claims 1 to 7, which is a copper alloy plate material for a connector. A connector formed using the copper alloy plate material according to claim 1. It is a manufacturing method of the copper alloy plate material according to any one of claims 1 to 8,
Casting [step 1], homogenizing heat treatment [step 2], chamfering [step 5], cold rolling [step 6], intermediate heat treatment [step 10], finish cold rolling [step 12] on copper alloy material, And temper annealing [step 13] in this order,
The roll diameter φ of the rolling mill in the cold rolling [step 6] is 50 mm or more and 200 mm or less,
The rolling rate R of the finish cold rolling [step 12] is 5% or more and 30% or less,
When the annealing temperature in the temper annealing [step 13] is T (° C.) and the tension applied in the rolling parallel direction is F (N/mm ² ), the annealing temperature (T) is 200° C. or higher and 400° C. A method for producing a copper alloy sheet material, which has the following value and in which the applied tension (F) in the direction parallel to the rolling satisfies the following expression (1) in relation to the annealing temperature.
−0.1×T+45≦F≦−0.1×T+80 (1)

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