JP5261691B2 - Copper-base alloy with excellent press punchability and method for producing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a copper alloy for connectors, lead frames, switches, relays, etc., which is excellent in press-blanking property. <P>SOLUTION: The copper alloy is obtained by: performing homogenizing anneal of an ingot of the copper alloy composed of 0.01-30 wt.% of at least one element chosen from the group consisting of Sn, Ni, P, Zn, Si, Fe, Co, Mg, Ti, Cr, Zr and Al and the balance being Cu and unavoidable impurities; repeating cold rolling and annealing; and performing cold-rolling at a reduction ratio Z% satisfying the relation: Z&ge;100-10X-Y [wherein Z is the cold-rolling reduction ratio (%); X is the content of Sn (wt.%) among the elements; and Y is the total content of elements other than Sn (wt.%)] and subsequently performing low-temperature anneal at a temperature below the recrystallization temperature. The obtained copper alloy has an X-ray diffracted intensity ratio S<SB>ND</SB>at the surface being S<SB>ND</SB>&ge;10, provided that S<SB>ND</SB>is represented by the formula: S<SB>ND</SB>=Iä220}&divide;Iä200} [wherein Iä220} is the X-ray diffracted intensity at ä220}; and Iä200} is the X-ray diffracted intensity at ä200}], shows a good balance among conductivity, strength, spring characteristic, hardness, bendability, etc. and is excellent in press-blanking property. <P>COPYRIGHT: (C)2009,JPO&amp;INPIT

Description

  The present invention relates to a copper-based alloy having excellent punchability and a method for producing the same, and more specifically, a consumer product, for example, an information / communication narrow pitch connector master, a semiconductor lead frame master and a small switch, The present invention relates to a copper-based alloy excellent in press punching properties that constitutes a relay original plate and the like, and a method for producing the same.

With the high-density mounting of home appliances, information communication devices, and automobile parts, connectors, switches, relays, and the like have been miniaturized, and the copper-based alloy materials that make up these components tend to be thinner and thinner.
These parts are often stamped by a high-speed press using a mold, and during the pressing process, the material undergoes shear deformation by the punch of the mold, and then breaks and deforms due to the generation of cracks from the blade edge. Is punched into a predetermined shape.
However, as the number of shots in the press increases, wear of the edge of the die punch advances, and as a result, the generation of cracks from the edge becomes uneven, the fracture shape is disturbed, specifically the shear band and the fracture band. The difference becomes large, large burrs are generated, and large waste of material generated by fracture is generated, so that a predetermined product shape cannot be maintained.
Conventionally, measures to improve the mold life have been dealt with by improving the material of the punch, improving the lubricity by press lubricant, and setting the clearance suitable for each copper base alloy. Could not be realized.
JP-A-5-279825 JP 63-266049 A

As a result of intensive studies to solve the problems of the conventional technology as described above, in the material of the narrow pitch connector and semiconductor lead frame that are punched into a predetermined shape by high-speed press molding using a mold, Thinning and narrowing of pin terminals, specifically, the pin thickness tends to be 0.10 to 0.25 mm and the pin width is 0.10 to 0.30 mm. Therefore, the balance of pin terminal strength and bendability was maintained. Above, the excellent press punchability has emerged as an important problem in the characteristics to be solved.
The present invention provides a copper-based alloy having excellent press punchability by controlling the crystal orientation of the material and a method for producing the same.
The pin terminal strength can be substituted by 0.2% proof stress of the material, and the pin terminal bendability is uniaxially deformed when W / t ≦ 4 when the thickness of the pin itself is tmm and the pin width is Wmm. Therefore, the elongation obtained by the tensile test can be substituted.

  The present invention is a copper-based alloy material, particularly by performing X-ray diffraction focusing on the ND surface (plate material surface; hereinafter referred to as ND surface), and by controlling the strength in a specific direction among the obtained crystal orientations, It was made based on the knowledge that a copper-based alloy with improved press punchability can be obtained. Specifically, for a copper-based alloy ingot containing a predetermined amount of elements such as Sn and Ni, it is cold-worked. This is realized by performing cold rolling at a processing rate equal to or higher than a predetermined value calculated from the content of alloy component elements other than copper, after rolling and then annealing. Note that the X-ray diffraction intensity indicates the integrated intensity of the crystal orientation of the material measured by, for example, the X-ray diffraction method.

That is, the present invention relates to 0.5 to 1.0 mass% Si, 0.3 to 3.0 mass% Sn, 0.4 to 4.0 mass% Ni, and 0.03 to 0.0 mass%. 50% by mass of Zn, optionally further 0.01 to 0.10% by mass of Mg, the balance being made of Cu and inevitable impurities, and the surface X-ray diffraction intensity ratio S _ND is S _ND ≧ 10 where S _ND = [I {220} + I {111} + I {311}] ÷ I {200}. I {220} is the X-ray diffraction intensity of {220}, I {111} is the X-ray diffraction intensity of {111}, I {311} is the X-ray diffraction intensity of {311}, and I {200} is {200} X-ray diffraction intensity when I {111} and I {311} exceed 1/10 of I {220}. The present invention provides a copper-based alloy having excellent press punching characteristics .
Moreover, 0.5-1.0 mass% Si, 0.3-3.0 mass% Sn, 0.4-4.0 mass% Ni, and 0.03-1.00 mass% Ingot of copper-based alloy containing the balance of Cu and inevitable impurities, or 0.5 to 1.0 mass% of Si, 0.3 to 3.0 mass% of Sn, 0 A copper group containing 0.4 to 4.0% by mass of Ni, 0.03 to 0.50% by mass of Zn, and 0.01 to 0.10% by mass of Mg with the balance being Cu and inevitable impurities The ingot of the alloy is subjected to a combination process consisting of cold rolling and then annealing at least once, and then cold rolling at a processing rate Z that satisfies the following formula (1).
Z ≧ 100−10X−Y (1)
[However, Z is the cold rolling ratio (%), X is the Sn content (mass%), Y is the total content (mass%) of elements other than Sn, Cu, and inevitable impurities. In some cases, the present invention provides a method for producing a copper-base alloy characterized by performing low-temperature annealing below the recrystallization temperature.
Prior to performing the combination step, at least one selected from homogenization annealing and hot rolling can be performed on the ingot in advance.

  The present invention reduces the wear of the punch edge due to press punching, improves press punchability, and has excellent balance of electrical conductivity, 0.2% proof stress, spring property, hardness and bendability, for connectors, switches and relays The copper base alloy has been obtained, and the cost has been reduced due to the thinning and thinning of the material and the improvement of the die life of the press due to the recent high-density mounting of home appliances, information communication equipment and automotive parts. The present invention provides a copper-based alloy that can realize a significant down.

The contents of the present invention will be specifically described below.
The present invention improves the press punching workability by controlling X-ray diffraction of a copper-based alloy, particularly focusing on the material surface, and controlling the strength of a specific orientation among the obtained crystal orientations.

First, in press working, it is important to align the crystal orientation to a certain orientation in order to achieve good fracture deformation by making the material shear deformation and crack generation from the punch blade edge uniform after shear deformation. It is. A Cu-based polycrystalline material having a crystal structure of FCC (face-centered cubic lattice) has a slip surface {111} and a slip direction <110> (where {} represents equivalent surfaces collectively, <> Is a combination of equivalent directions (orientations)), that is, 12 slip systems {111} <110>, and one or more slip systems are activated during deformation. In the case of press shear deformation, a slip system having the smallest angle with the punching direction is activated.
Now, with the surface of the plate as the ND surface, paying attention to the four main types of planes, {110} plane, {111} plane, {311} plane, and {100} plane, the punch punching direction coincides with the press shear deformation. The {110} plane having two slip systems is most effective in improving the press punchability, and then the {111} plane, {311} plane having a slip system having a relatively small angle with the punching direction of the punch, On the other hand, the {100} plane with an angle of 45 ° among the 8 slip systems out of 12 slip systems with respect to the punching direction of the punch deteriorates the press punchability most. Specifically, the stress applied to the cutting edge of the punch is large, the wear of the cutting edge is promoted, the metal powder generated at the time of breaking deformation increases, and adheres between the molds (between the punch and the die). Promoting the wear of the cutting edge, resulting in an increased burr height of the material after fracture.
Here, in the case of a metal having an FCC (face-centered cubic lattice) crystal structure such as a copper-based alloy, X of the {110} plane, {111} plane, {311} plane, and {100} plane is obtained by X-ray diffraction. Line diffraction intensities (hereinafter referred to as diffraction intensities) are generated as I {220}, I {111}, I {311}, and I {200}, respectively.

As a result of diligent research to solve the conventional problems in consideration of the above, the diffraction intensity I {220} of the {220} plane, the diffraction intensity I {111} of the {111} plane, and the diffraction intensity of the {311} plane Measure the diffraction intensity I {200} of I {311}, {200} plane,
S _ND = I {220} ÷ I {200}
By introducing the parameter S _ND and controlling the structure using this parameter, it was possible to improve press punchability. That is, when S _ND ≧ 10, the shape of the terminal punched out by the press was good.
On the other hand, when S _ND <10, as the number of press shots increased, wear of the cutting edge advanced and the shape of the punched terminal deteriorated.

Depending on the type of copper-based alloy, the diffraction intensity I {311} of the {311} plane exceeds 1/10 of the diffraction intensity I {220} of the {220} plane, or the diffraction intensity I {111 of the {111} plane } Exceeds 1/10 of the diffraction intensity I {220} of the {220} plane, or the diffraction intensity I {111} of the {111} plane and the diffraction intensity I {311} of the {311} plane are {220} planes When it exceeds 1/10 of the diffraction intensity I {220} of
S _ND = I {220} ÷ I {200}
Each
S _ND = [I {220} + I {311}] ÷ I {200}
Or
S _ND = [I {220} + I {111}] ÷ I {200}
Or
S _ND = [I {220} + I {111} + I {311}] ÷ I {200}
It is desirable to deal with.

  Next, the total composition of at least one element selected from Sn, Ni, P, Zn, Si, Fe, Co, Mg, Ti, Cr, Zr, and Al is included in the component composition range of the copper-based alloy according to the present invention. The content of 0.01 to 30 wt%, with the balance consisting of Cu and inevitable impurities, maintains the balance of electrical conductivity, tensile strength, 0.2% proof stress, elongation and bendability of the material, and also provides press punchability. It is for improving.

When the total content of at least one element selected from Sn, Ni, P, Zn, Si, Fe, Co, Mg, Ti, Cr, Zr, and Al is less than 0.01 wt%, the conductivity is Although higher, it is difficult to obtain properties such as tensile strength, 0.2% proof stress and press punchability. In addition, the tensile strength and 0.2% proof stress can be improved by increasing the rolling rate to 98%, but the press punchability cannot be significantly improved, and the bending workability deteriorates. On the other hand, if the total content of at least one element selected from Sn, Ni, P, Zn, Si, Fe, Co, Mg, Ti, Cr, Zr, and Al exceeds 30 wt%, Strength and 0.2% yield strength can be improved, but the electrical conductivity is lowered, and the bending workability is further deteriorated.
Accordingly, the component composition range of the copper-based alloy according to the present invention is at least one element selected from Sn, Ni, P, Zn, Si, Fe, Co, Mg, Ti, Cr, Zr, and Al as a total amount. It was defined as a copper-based alloy containing 0.01 to 30 wt% with the balance being Cu and inevitable impurities. In addition to the above elements defined in the present invention, for example, at least one element selected from the elements of Ag, Au, Bi, In, Mn, La, Pb, Pd, Sb, Se, Te, and Y If the total amount of elements is 2 wt% or less, further inclusion in the above-mentioned elements defined in the present invention will play a role of improving press punchability and will not hinder the obtained effect.
Next, the main additive elements defined in the present invention will be described.

(1) Sn
Sn is an essential element for achieving both press punchability, strength and elasticity.
Sn can be dissolved in a Cu matrix to reduce press punchability and greatly reduce the degree of integration of {200} planes. Furthermore, in combination with thermomechanical treatment, {220} planes, {111} planes, I {311 } The integration degree of the surface can be greatly increased, and as a result, the press punchability can be improved. At the same time, strength and elasticity can be improved. However, if the Sn content is less than 0.01 wt%, the effect cannot be obtained sufficiently. On the other hand, if the Sn content exceeds 10 wt%, the electrical conductivity decreases significantly, and the castability and hot workability are also adversely affected. Effect. Moreover, since Sn is expensive, it becomes economically disadvantageous. Therefore, the Sn content is 0.01-10 wt%, preferably 0.3-3.0 wt%.

(2) Ni
Ni dissolves in the Cu matrix to improve strength, elasticity, and solderability. Furthermore, P or, in some cases, forms a compound with Si to disperse and precipitate to improve electrical conductivity. Improve. It is also an element that contributes to the improvement of heat resistance and stress relaxation resistance. However, when the Ni content is less than 0.01 wt%, the above effects cannot be sufficiently obtained.On the other hand, when the Ni content exceeds 4.0 wt%, the electrical conductivity is significantly reduced even in the presence of P or Si. It becomes economically disadvantageous. Therefore, the Ni content is 0.01 to 4.0 wt%, preferably 0.40 to 3.0 wt%.

(3) P
P acts as a deoxidizer for molten metal during melting and casting, and improves electrical conductivity by forming a compound with Ni or, optionally, Fe, Mg, or Co, and further improving strength and elasticity. Let However, if the P content is less than 0.01 wt%, the above effects cannot be sufficiently obtained.On the other hand, if it exceeds 0.20 wt%, the electrical conductivity is remarkably lowered even in the presence of Ni, or in some cases Fe, Mg, or Co. Solder weather resistance is significantly deteriorated. It also adversely affects hot workability. Therefore, the P content is 0.01 to 0.20 wt%, preferably 0.02 to 0.10 wt%.

(4) Zn
Zn dissolves in the Cu matrix and has the effect of improving strength and elasticity. In addition to the effect of increasing the deoxidation effect of the molten metal and reducing the solute oxygen element in the Cu matrix, solder weather resistance and migration resistance Has the effect of improving the performance. However, if it is less than 0.01 wt%, the above effect cannot be obtained.On the other hand, if it exceeds 30 wt%, not only the electric conductivity is lowered, but also the solderability is lowered, and even when combined with other elements, it is resistant. Stress corrosion cracking susceptibility is increased, which is not preferable. Therefore, the Zn content is 0.01-30 wt%, preferably 0.01-10 wt%, more preferably 0.03-3.0 wt%.

(5) Si
Si precipitates in the Cu matrix in the state of coexisting with Ni to form a compound and has the effect of improving strength and elasticity without significantly reducing the conductivity. If Si is less than 0.01 wt%, the above effects cannot be obtained. On the other hand, if it exceeds 1.0 wt%, hot workability is remarkably lowered. Therefore, the Si content is set to 0.01 to 1.0 wt%.

(6) Fe, Co, Mg, Ti, Cr, Zr, Al
These elements have the effect of forming a compound by solid solution or precipitation in the Cu matrix to improve the strength, elasticity and heat resistance, and further improve the press punchability. However, if it is less than 0.01 wt%, the above effects cannot be obtained.On the other hand, if it exceeds 3.0 wt%, the electrical conductivity is remarkably lowered, and the heat treatment temperature at the time of production is high, which is economically disadvantageous. Become. Therefore, the total content of the at least one element is 0.01 to 3.0 wt%.

(7) Oxygen When a large amount of oxygen is contained, Fe, Mg, P, etc. may form oxides, which may deteriorate various characteristics of the copper-based alloy according to the present invention including plating reliability. The oxygen content is 20 ppm or less.

Next, the reason why the processing steps including the heat treatment of the copper base alloy according to the present invention are limited as described above will be described.
The material of the present invention can be manufactured through the following steps. That is, after the ingot of the copper-based alloy having the above component composition is made into a predetermined plate thickness by repeating cold rolling and annealing, it is specifically processed at a processing rate equal to or higher than a predetermined value obtained based on the content of the element. In this case, cold rolling at a cold rolling processing rate Z (%) satisfying the expression (1) is performed, and a material having a desired plate thickness is obtained by combining low temperature annealing below the recrystallization temperature.

The effect of homogenizing the solute element distribution by removing the micro or macro segregation of solute elements that occurred during casting by pre-homogenizing annealing or hot rolling before cold rolling the ingot. In particular, by hot rolling, the crystal orientation of the ingot can be made random, the crystal grains can be made uniform and fine, and the rolling rate can be increased, which is economically advantageous. Therefore, at least one of homogenization annealing and hot rolling is preferably performed before cold rolling the ingot. These homogenization annealing and hot rolling are preferably performed at 700 ° C. to 900 ° C. for 30 minutes to 2 hours.
Cold rolling processing rate Z (%) ≧ 100−10X−Y (1)
X: Sn content (wt%)
Y: Content of the element other than Sn (wt%)

The cold rolling processing rate Z (%) is determined as in the formula (1) because each additional element is pressed on the ND surface by cold rolling at a rolling processing rate that satisfies the formula (1). The degree of integration of {200} faces that degrade punchability is greatly reduced, while the degree of integration of {220} faces, {111} faces, {311} faces, especially {220} faces that improve press punchability The press punchability improved. At this time, S _ND satisfied S _ND ≧ 10. Furthermore, the tensile strength and 0.2% proof stress could be improved, and the elongation that had decreased with the increase of the rolling rate could be improved. Further, when low temperature annealing below the recrystallization temperature is performed after cold rolling, the accumulation ratio of {200} plane, {220} plane, {111} plane, {311} plane hardly changes, and the tensile strength is 0.2 Since% proof stress can be maintained, press punchability similar to that of rolled material can be maintained. Furthermore, elongation, that is, bendability can be improved by low-temperature annealing.
Therefore, it is most desirable to combine cold rolling with a cold rolling processing rate Z (%) satisfying the expression (1) and low-temperature annealing below the recrystallization temperature. The low-temperature annealing condition at this time is preferably 30 to 2 hours at a temperature lower by 50 ° C. to 250 ° C. than the recrystallization temperature of the copper-based alloy. For example, the temperature is 250 ° C. to 350 ° C., 30 minutes to 1 hour. Even under these conditions, the characteristics can be expressed as long as the combination of temperature and time can give the same amount of heat to the material.

On the other hand, at the rolling processing rate not satisfying the formula (1), the {200} plane integration degree hardly decreased, the {220} plane integration degree did not increase much, and the press punchability could not be improved. The S _ND at this time was S _ND <10. Furthermore, at the rolling processing rate not satisfying the formula (1), the tensile strength and 0.2% proof stress improved with the increase of the processing rate, but the elongation deteriorated and as a result, the bendability deteriorated. In addition, when low temperature annealing below the recrystallization temperature is performed after cold rolling, the accumulation ratio of {200} plane, {220} plane, {111} plane, {311} plane is hardly changed, and the press punchability We cannot expect improvement. Furthermore, when trying to improve the bending workability, the tensile strength and 0.2% proof stress deteriorated, and the balance between the two could not be maintained.

As a representative example of the above phenomenon, FIG. 1 shows the relationship between the rolling rate of Cu-1.0 wt% Ni-0.90 wt% Sn-0.05 wt% P and the degree of integration of each crystal orientation on the ND plane, and FIG. The relationship between the rolling rate of 1.0wt% Ni-0.90wt% Sn-0.05wt% P and the tensile strength, 0.2% proof stress, and elongation is shown. At this time, the cold rolling processing rate satisfying the expression (1) is Z (%) ≧ 89.95%. From Fig. 1, when Z (%) ≥ 89.95%, the integration of {200} faces that deteriorates press punchability is significantly reduced, and at the same time, the integration of {220} faces that improve press punchability is greatly increased. I understand that The S _ND at this time was S _ND = 22 in S _ND = 12,92.5% 90% rolling ratio. From FIG. 2, it is worth noting that the tensile strength and 0.2% proof stress can be improved and the elongation can be further improved.

  Examples of the present invention will be described below.

[Example 1]
Copper base alloys Nos. 1 to 4, Nos. 6 to 9, and Nos. 11 to 16 whose chemical composition values (wt%) are shown in Table 1 are dissolved in an Ar atmosphere. A x80 x 1000 (mm) ingot was cast, and the resulting ingot was subjected to a homogenization heat treatment at 900 ° C for 1 hour. Thereafter, the plate materials No. 1 to 4, No. 6 to 9, and No. 11 to 16 were hot-rolled from a plate thickness of 20 mm to 6.0 mm, followed by water quenching and pickling after rolling. By cold rolling the obtained plate material with a thickness of 6.0 mm, No.1, 7, and 8 are up to 2.5 mm thick, No.2, 3, and 16 are up to 2.0 mm thick, No.4, 6, 15 Is up to 1.0mm, No.9 is up to 3.5mm, No.11 is up to 0.6mm, No.12 is up to 0.5mm, No.13 is up to 0.3mm, No.14 Each was rolled to a thickness of 0.23 mm.
On the other hand, copper base alloys No. 5, 10, 17, and 18 were melted in an Ar atmosphere, and a 10 × 80 × 1000 (mm) ingot was cast using a horizontal continuous casting machine. Homogenization heat treatment was performed at 800 ° C for 1 hour. After that, cold rolling, annealing, and cold rolling were repeated until No. 5 was up to 0.6 mm thick, No. 10 was up to 0.3 mm thick, No. 17 was up to 0.25 mm thick, No. 18 was the board Each was rolled to a thickness of 0.24 mm.
The plate materials No. 1 to 18 obtained as described above were heat-treated at 550 ° C. for 1 hour. The crystal grain size of the sheet material after the heat treatment is 5 to 20 [mu] m, the result of measuring the S _ND subjected to X-ray diffraction analysis sheet surface (ND plane), which are made by those that were 0.5 ≦ S _ND <2.0 .
Here, the measurement conditions of the X-ray diffraction intensity are as follows.
Tube: Cu, tube voltage: 40 kV, tube current: 30 mA, sampling width: 0.020 °, monochromator used, sample holder: Al
Note that the X-ray diffraction measurement conditions are not limited to the above conditions, and are appropriately changed depending on the type of the sample.

Cold rolling was performed on No. 1 to 18 obtained in this way, finishing to a plate thickness of 0.20 mm, and finally, a heat treatment of 300 ° C. for 30 minutes that is less than the recrystallization temperature was performed, A sample for evaluation was used.
For a sample of No.1~18 obtained in this manner it was first measured S _ND evaluation. Subsequently, the electrical conductivity, 0.2% proof stress, 180 ° bendability, and press punchability were evaluated. Electrical conductivity and 0.2% proof stress were measured and evaluated in accordance with JIS H 0505 and JIS Z 2241, respectively. The bendability is determined by a 180 ° bend test (based on JIS H3110). A test piece with a pin width of 0.50 mm is punched out in a direction parallel to the rolling direction. The ratio was R / t, and the evaluation was performed with the minimum R / t at which no cracks occurred on the surface of the bent portion. The press punchability was evaluated by measuring the maximum burr height of the material after punching 50,000 shots by SEM observation after carrying out continuous press processing of a pin shape with a pin width of 0.50 mm.

From the results in Table 1, the following is clear.
Alloy N O.1～10 is, S satisfies _ND ≧ 10 cold rolling ratio Z (%) ≧ 100-10X-Y is satisfied, burr height after punching is at 10μm or less It is a copper-based alloy material excellent in press punchability. Furthermore, the balance of conductivity, 0.2% proof stress, and bendability was excellent.
On the other hand, Comparative Examples Nos. 11 to 18 in which the cold rolling reduction rate is lower than the ideal cold rolling reduction rate (Z (%) ≧ 100−10X−Y) are S _ND <10 and the burr height after press punching Was over 10 μm. Moreover, among No.15-18, whose burr height was relatively close to 10 μm, No.15 and 16 were excellent in the balance between conductivity and 0.2% proof stress, but the bendability was deteriorated. 17 and 18 were excellent in the balance between 0.2% proof stress and bendability, but the conductivity was as low as 15% IACS or less.

[Example 2]
Table 1 shows to alloy in No.1 of Example 1 (thickness 0.20 mm) and a commercial phosphor bronze alloy (C5191 temper H, thickness 0.20mm: 6.5wt% Sn, 0.2wt% P, balance Cu ) And copper base alloy (C7025 grade H, thickness 0.20mm: 3.2wt% Ni, 0.70wt% Si, 0.15wt% Mg, balance Cu), conductivity, 0.2% proof stress, spring limit, Vickers hardness The press workability and bending workability were evaluated.
Measurements of electrical conductivity, 0.2% proof stress, spring limit value, and Vickers hardness were performed in accordance with JIS H 0505, JIS Z 2241, JIS H 3130, and JIS Z 2244, respectively. The press workability is the same as in Example 1. The terminal with a pin width of 0.50 mm is continuously punched, and the press work is stopped when the burr height of the material exceeds 25 μm. Rated as a number. At this time, the punch material of the press was super steel, the material of the die was die steel, the clearance between the punch and the die was 8 μm, and the rotational speed of the press was 250 rpm. For bending workability, a 180 ° bending test (conforming to JIS H 3110) was used to punch out a test piece with a pin width of 0.50 mm, and the ratio of the inner bending radius R to the thickness t of the obtained test piece was R / t. The evaluation was performed with the minimum R / t at which cracks did not occur on the surface of the bent part. The results are shown in Table 2.

From the results shown in Table 2, the No. 1 copper-based alloy has conductivity, 0.2% proof stress, spring limit value, compared with the conventional copper-based alloys C5191 and C7025 for typical connectors, switches and relays. It can be seen that it has an excellent balance of Vickers hardness, press workability, and bending workability, and has the 0.2% proof stress in the 90 ° direction, the spring limit value, and the bending workability that are particularly necessary for pinched pitch connectors.

It is a figure which shows the relationship between a cold rolling processing rate, orientation density, and _SND . It is a figure which shows the relationship between a cold rolling process rate, tensile strength, 0.2% yield strength, and elongation.

Claims (7)

0.5 to 1.0% by mass of Si, 0.3 to 3.0 % by mass of Sn, 0.4 to 4.0 % by mass of Ni, and 0.03 to 1.00% by mass of Zn The balance is made of Cu and inevitable impurities, and the surface X-ray diffraction intensity ratio S _ND is S _ND ≧ 10 [where S _ND = [I {220} + I {111} + I {311}] ÷ I {200}. I {220} is the X-ray diffraction intensity of {220}, I {111} is the X-ray diffraction intensity of {111}, I {311} is the X-ray diffraction intensity of {311}, and I {200} is {200} X-ray diffraction intensity when I {111} and I {311} exceed 1/10 of I {220}. ] A copper-based alloy having excellent press punching characteristics. 0.5 to 1.0 mass% Si, 0.3 to 3.0 mass% Sn, 0.4 to 4.0 mass% Ni, and 0.03 to 0.50 mass% Zn And 0.01 to 0.10 % by mass of Mg, the balance is made of Cu and inevitable impurities, and the surface X-ray diffraction intensity ratio S _ND is S _ND ≧ 10 [where S _ND = [I {220} + I {111} + I {311}] ÷ I {200}. I {220} is the X-ray diffraction intensity of {220}, I {111} is the X-ray diffraction intensity of {111}, I {311} is the X-ray diffraction intensity of {311}, and I {200} is {200} X-ray diffraction intensity when I {111} and I {311} exceed 1/10 of I {220}. ] A copper-based alloy having excellent press punching characteristics. 0.50 to 0.70% by mass of Si, 0.30 to 0.52% by mass of Sn, 2.00 to 3.20% by mass of Ni, and 0.50 to 1.00% by mass of Z n is contained, the balance is made of Cu and inevitable impurities, and the surface X-ray diffraction intensity ratio S _ND is 12 to 20 [where S _ND = [I {220} + I {111} + I {311}] ÷ I {200}. I {220} is the X-ray diffraction intensity of {220}, I {111} is the X-ray diffraction intensity of {111}, I {311} is the X-ray diffraction intensity of {311}, and I {200} is {200} X-ray diffraction intensity when I {111} and I {311} exceed 1/10 of I {220}. ] A copper-based alloy having excellent press punching characteristics. 0.50 to 0.70 mass% Si, 0.30 to 0.52 mass% Sn, 2.00 to 3.20 mass% Ni, and 0.50 to 1.00 mass% Zn And 0.01 to 0.10% by mass of Mg, the balance is made of Cu and inevitable impurities, and the surface X-ray diffraction intensity ratio S _ND is 12 to 20 [where S _ND = [I { 220} + I {111} + I {311}] ÷ I {200}. I {220} is the X-ray diffraction intensity of {220}, I {111} is the X-ray diffraction intensity of {111}, I {311} is the X-ray diffraction intensity of {311}, and I {200} is {200} X-ray diffraction intensity when I {111} and I {311} exceed 1/10 of I {220}. ] A copper-based alloy having excellent press punching characteristics. 0.5 to 1.0% by mass of Si, 0.3 to 3.0 % by mass of Sn, 0.4 to 4.0 % by mass of Ni, and 0.03 to 1.00% by mass of Zn Ingot of copper-based alloy containing Cu and inevitable impurities, or 0.5 to 1.0% by mass of Si, 0.3 to 3.0 % by mass of Sn, 0.4 to 4.0 mass% of Ni, 0.03 to 0.50 mass% of Zn, and containing 0.01 to 0.10 mass% of Mg, the balance being copper base alloy consisting of Cu and unavoidable impurities After performing the combined process consisting of cold rolling and then annealing the ingot at least once, then cold rolling at a processing rate Z satisfying the following formula (1) Z ≧ 100−10X−Y (1 )
[However, Z is the cold rolling ratio (%), X is the Sn content (mass%), Y is the total content (mass%) of elements other than Sn, Cu, and inevitable impurities. ] A method for producing a copper-based alloy. 0.5 to 1.0% by mass of Si, 0.3 to 3.0 % by mass of Sn, 0.4 to 4.0 % by mass of Ni, and 0.03 to 1.00% by mass of Zn Ingot of copper-based alloy containing Cu and inevitable impurities, or 0.5 to 1.0% by mass of Si, 0.3 to 3.0 % by mass of Sn, 0.4 to 4.0 mass% of Ni, 0.03 to 0.50 mass% of Zn, and containing 0.01 to 0.10 mass% of Mg, the balance being copper base alloy consisting of Cu and unavoidable impurities The ingot is cold rolled and then annealed at least once, and then cold rolled at a processing rate Z that satisfies the following formula (1): Z ≧ 100−10X−Y (1 )
[However, Z is the cold rolling ratio (%), X is the Sn content (mass%), Y is the total content (mass%) of elements other than Sn, Cu, and inevitable impurities. Next, a method for producing a copper-base alloy, characterized by performing low-temperature annealing below the recrystallization temperature. The method according to claim 5 or 6 , wherein at least one selected from homogenization annealing and hot rolling is performed on the ingot in advance prior to performing the combination step.

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