KR20140053376A - Cu-ni-si alloy and method for manufacturing same - Google Patents

Abstract

A Cu-Ni-Si alloy having excellent strength and bending workability, which is preferable as a conductive spring material for connectors, terminals, relays, switches and the like, and a method for producing the same. 1.0 to 4.5% by mass of Ni and 0.2 to 1.0% by mass of Si, and the balance of copper and inevitable impurities, and subjected to EBSD (Electron Back-Scatter Diffraction) The area ratio of the Cube orientation {0 0 1} <1 0 0> is not less than 5%, the area ratio of the Brass orientation {1 1 0} <1 1 2> is not more than 20% } A Cu-Ni-Si alloy having an area ratio of <1 1 1> of 20% or less and a work hardening index of 0.2 or less.

Description

[0001] The present invention relates to a Cu-Ni-Si alloy and a method of manufacturing the same.

The present invention relates to a copper alloy having excellent strength and bending workability, which is preferable as a conductive spring material for connectors, terminals, relays, switches and the like, and a manufacturing method thereof.

BACKGROUND ART [0002] In recent years, with the miniaturization of electronic devices, miniaturization of electric / electronic parts has been progressing. The copper alloy used for these parts is required to have good strength and electrical conductivity.

In the case of a vehicle-use terminal, a copper alloy to be used along with miniaturization is required to have good strength and conductivity. Further, in many cases, the vehicle arm terminal is subjected to a lancing process called a notching process on the bending inner surface before the press bending process. This is a process performed to improve the shape accuracy after press bending. With the miniaturization of products, the notching process tends to deepen in order to further improve the shape accuracy of the terminal. Therefore, the copper alloy used for the female terminal for vehicle use is required to have good strength and conductivity as well as good bending workability. Further, in the relay terminal, the bending workability is required for the material because the contact bending is performed in order to obtain the desired strength of the material with the miniaturization.

In response to this demand, precipitation hardening type copper alloys such as a Korson alloy having high strength and electrical conductivity have been used instead of conventional solid solution copper alloys such as phosphor bronze and brass, and their demand is increasing. Among the Korson alloys, the Cu-Ni-Si alloy has high strength and relatively high conductivity. The strengthening mechanism improves the strength and the conductivity by depositing Ni-Si intermetallic compound particles in the Cu matrix.

Generally, strength and bending workability are opposite to each other, and it is desired to improve the bending workability of Cu-Ni-Si alloy while maintaining high strength.

As a method for improving the bending workability of a Cu-Ni-Si alloy, there is a method of controlling the crystal orientation as described in Patent Documents 1 to 3. [ In Patent Document 1, by setting the area ratio of {0 0 1} <1 0 0> of the EBSD analysis measurement result to 50% or more, the area of {0 0 1} <1 0 0> The area ratio of {1 1 0} <1 1 2> of the EBSD analysis measurement result is not more than 20% and the area ratio of {1 2 1} <1 2> is not more than 50% 1 1 1> is not more than 20%, and the area ratio of {0 0 1} <1 0 0> is 5 to 60%, the bending workability is improved.

In Patent Document 4, the bending formability is improved by setting the work hardening index to 0.05 or more.

Patent Document 1: JP-A-2006-283059 Patent Document 2: JP-A-2006-152392 Patent Document 3: JP-A-2011-017072 Patent Document 4: JP-A-2002-266042

The present inventors conducted a verification test on the effects of the above-described prior art. As a result, when the bending workability was evaluated by W bending with a bending radius of 0.15 mm (bending radius / plate thickness = 1) with respect to the technique of Patent Document 3, a certain improvement effect was recognized, but a bending radius of 0.075 mm / Plate thickness = 0.5), it was found that the improvement of the bending workability was insufficient due to the occurrence of cracks. It is therefore an object of the present invention to provide a Cu-Ni-Si based alloy having excellent strength and bending workability, which is preferable as a conductive spring material for connectors, terminals, relays, switches and the like, and a method for producing the same.

In the prior art, the bending workability of the Cu-Ni-Si alloy is improved by controlling the crystal orientation of the copper alloy. However, not only the crystal orientation control but also the work hardening index (n value) is controlled to obtain excellent bending workability I found out.

The present invention has been completed with the above background in view. In one aspect of the present invention, there is provided a method of manufacturing a semiconductor device, comprising: 1.0 to 4.5% by mass of Ni and 0.2 to 1.0% by mass of Si; the balance of copper and inevitable impurities; Scatter Diffraction (electron backscattering diffraction) measurements were carried out to analyze the crystal orientation, the area ratio of the Cube orientation {0 0 1} <1 0 0> was 5% or more and the Brass orientation {1 1 0} <1 1 2 > Is a Cu-Ni-Si alloy having an area ratio of 20% or less, an area ratio of copper orientation {1 1 2} <1 1 1> of 20% or less and a work hardening index of 0.2 or less.

In one embodiment, the Cu-Ni-Si alloy according to the present invention contains at least one of Sn, Zn, Mg, Fe, Ti, Zr, Cr, Al, P, Mn, 0.005 to 2.5% by mass.

According to another aspect of the present invention, there is provided an ingot comprising 1.0 to 4.5% by mass of Ni and 0.2 to 1.0% by mass of Si, the remainder being copper and inevitable impurities, and the ingot is hot-rolled then, subjected to cold-rolling and softening even after subjected to the heat treatment of 0.25 to 0.75, formability 7 and subjected to 50% cold rolling, and then, after subjected to a solution treatment, aging treatment and a deformation rate 1 × 10 ^{- 4} (1 / sec) or less in an arbitrary order according to the method of manufacturing a Cu-Ni-Si alloy according to the present invention.

A method of producing a Cu-Ni-Si alloy according to the present invention is a method of manufacturing a Cu-Ni-Si alloy according to one embodiment of the present invention, wherein the ingot is at least one of Sn, Zn, Mg, Fe, Ti, Zr, Cr, Al, P, Mn, And 0.005 to 2.5% by mass of at least one of them.

According to another aspect of the present invention, there is provided a new copper alloy product (copper alloy product) comprising the copper alloy.

According to another aspect of the present invention, there is provided an electronic device part comprising the copper alloy.

According to the present invention, it is possible to provide a Cu-Ni-Si alloy having excellent strength and bending workability, which is preferable as a conductive spring material for a connector, a terminal, a relay, a switch and the like, and a manufacturing method thereof.

1 is a graph showing the relationship between the annealing temperature and the tensile strength when the Cu-Ni-Si alloy according to the present invention is annealed at various temperatures.

(Ni and Si concentration)

Ni and Si are precipitated as intermetallic compounds such as Ni ₂ Si by aging treatment. This compound improves the strength and improves the conductivity by precipitating Ni and Si dissolved in the Cu matrix. However, if the Ni concentration is less than 1.0% by mass or the Si concentration is less than 0.2% by mass, desired strength can not be obtained. Conversely, if the Ni concentration exceeds 4.5% by mass or if the Si concentration exceeds 1.0% by mass, do. Therefore, in the Cu-Ni-Si based alloy according to the present invention, the Ni concentration is controlled to 1.0 to 4.5 mass% and the Si concentration to 0.2 to 1.0 mass%. The Ni concentration is preferably 1.3 to 4.0 mass%, and the Si concentration is preferably 0.3 to 0.9 mass%.

(Other added elements)

The addition of Sn, Zn, Mg, Fe, Ti, Zr, Cr, Al, P, Mn, Co, Cr and Ag contributes to the strength increase. Zn is effective for improving the heat peelability of Sn plating, Mg for improving stress relaxation property, and Zr, Cr and Mn for improving hot workability. If the total concentration of Sn, Zn, Mg, Fe, Ti, Zr, Cr, Al, P, Mn, Co, Cr and Ag is less than 0.005 mass%, the above effect can not be obtained. Conversely, And thus it can not be used as a material for electric / electronic parts. Therefore, in the Cu-Ni-Si alloy according to the present invention, the total amount of these elements is preferably 0.005 to 2.5 mass%, more preferably 0.1 to 2.0 mass%.

(Crystal orientation)

In a copper alloy, uneven deformation is suppressed and the bendability is improved when the Cube orientation is large and the Brass orientation and the Copper orientation are small. Here, the Cube bearing is a state in which the (001) plane faces the rolling plane normal direction ND and the (1 0 0) plane faces the rolling direction RD, and the index of {0 0 1} <1 0 0> Respectively. The Brass bearing is a state in which the (1 1 0) plane is directed to ND and the (1 1 2) plane is oriented to RD, and is expressed by the exponent of {1 1 0} <1 1 2>. Copper bearing indicates the (1 1 2) plane in ND and the (1 1 1) plane in RD, and is expressed by the exponent of {1 1 2} <1 1 1>.

The area ratio of the Cube orientation in the Cu-Ni-Si based alloy according to the present invention is controlled to 5% or more. When the area ratio of the Cube orientation is less than 5%, the bending workability deteriorates sharply. The upper limit value of the area ratio of the Cube orientation is not regulated in terms of the bending property. However, in the case of the Cu-Ni-Si based alloy according to the present invention, when the area ratio of the Cube orientation exceeds 80% none.

The Cu-Ni-Si alloy according to the present invention is controlled so that the area ratio of the copper orientation and the brass orientation is respectively 20% or less. If either the area ratio of the copper orientation or the area ratio of the brass orientation is more than 20%, the bending workability deteriorates sharply. Although the lower limit value of the area ratio of the copper orientation and the brass orientation is not regulated in terms of the bendability, in the case of the Cu-Ni-Si based alloy according to the present invention, the area ratio of the copper orientation or the Brass orientation Either one of the area ratios is not less than 1%.

(Work hardening coefficient)

When the metal is plastic-deformed, deformation is deposited, work hardening occurs, and the tensile strength of the metal is increased. The work hardening coefficient (hereinafter referred to as n value) is a value used as an index of work hardening. The larger the value of n, the greater the increase in tensile strength due to work hardening.

In order to form the material into an electronic component such as a connector, press bending must be performed. When the material is subjected to press bending, the material is work-hardened and its tensile strength is increased.

In general, the tensile strength and the bending workability of the material are in a trade-off relationship, and the higher the tensile strength, the worse the bending workability.

Therefore, if increase in tensile strength due to work hardening due to press bending of the material is suppressed, cracks are less likely to occur during press bending. In other words, the smaller the value of n, the better the bending workability is obtained.

The n value of the Cu-Ni-Si based alloy according to the present invention is controlled to 0.2 or less. The value of n is preferably 0.1 or less, more preferably 0.05 or less. When the value of n exceeds 0.2, the bending workability deteriorates sharply. The lower limit of the value of n is not regulated in terms of bendability. However, in the case of the Cu-Ni-Si alloy according to the present invention, the value of n does not become less than 0.01 regardless of how the manufacturing method is changed.

(Manufacturing method)

In the manufacturing method of the present invention, first, a raw material such as electric copper, Ni, Si or the like is dissolved in a melting furnace to obtain a molten metal having a desired composition. Then, the molten metal is cast into an ingot. Thereafter, the steel sheet is finished with a hot rolled steel sheet, a first cold rolling sheet, a heat treatment, a second cold rolling, a solution treatment, an aging treatment and a third cold rolling in the order of a desired thickness and properties . After the heat treatment, the solution treatment and the aging treatment, the surface may be pickled or polished to remove the surface oxide film formed during heating. The order of the aging treatment and the third cold rolling may be changed. For high strength, cold rolling may be performed between the solution treatment and the aging. Further, deformation removing annealing may be performed after the third cold rolling in order to recover the lowering of the spring limit value by the third cold rolling.

In the present invention, before the solution treatment, heat treatment (hereinafter referred to as preliminary annealing) and second cold rolling with relatively low cost are performed to obtain the crystal orientation. The preliminary annealing is performed under the condition that the softness S is 0.25 to 0.75.

Fig. 1 illustrates the relationship between the annealing temperature and the tensile strength when the Cu-Ni-Si alloy according to the present invention is annealed at various temperatures. The sample equipped with the thermocouple was put into a furnace heated to a predetermined temperature, and when the sample temperature measured at the thermocouple reached a predetermined temperature, the sample was taken out from the furnace and cooled down to measure the tensile strength. The recrystallization proceeded at a sample arrival temperature of 500 to 700 ° C, and the tensile strength rapidly dropped. The gradual reduction of the tensile strength on the high temperature side is due to the growth of the recrystallized grains.

The degree of softening S in the preliminary annealing is defined by the following equation.

S = (? _{0 -} ?) / (? _{0 -} ? ₉₀₀ )

Where? ₀ is the tensile strength before pre-annealing,? And? ₉₀₀ are the tensile strength after pre-annealing and after annealing at 900 占 폚, respectively. The temperature of 900 占 폚 is adopted as a reference temperature for determining the tensile strength after recrystallization in that the Cu-Ni-Si based alloy according to the present invention is annealed at 900 占 폚 to be stably completely recrystallized.

When S is less than 0.25, the area ratio of the copper orientation increases to exceed 20%, accompanied by a decrease in the area ratio of the Cube orientation.

If S exceeds 0.75, the area ratio of the Brass orientation increases to exceed 20%, accompanied by a decrease in the area ratio of the Cube orientation.

The temperature, time and cooling rate of the preliminary annealing are not particularly limited, and it is important to adjust S to the above range. Generally, when a continuous annealing furnace is used, the furnace temperature is in the range of 400 to 700 ° C for 5 seconds to 10 minutes, and in the batch annealing furnace, the furnace temperature is in the range of 350 to 600 ° C for 30 minutes to 20 hours.

The adjustment of the softening degree S from 0.25 to 0.75 can be carried out in the following order.

(1) Measure the tensile test strength (σ ₀ ) of the pre-annealed material.

(2) The material before the pre-annealing is annealed at 900 占 폚. Specifically, the material with the thermocouple is inserted into the tubular furnace at 950 ° C., and when the sample temperature measured at the thermocouple reaches 900 ° C., the sample is taken out of the furnace and cooled.

(3) The tensile strength (? ₉₀₀ ) of the material after the 900 占 폚 annealing is obtained.

(4) For example, when σ ₀ is 800 MPa and σ ₉₀₀ is 300 MPa, tensile strengths corresponding to softenings of 0.25 and 0.75 are 675 MPa and 425 MPa, respectively.

(5) Annealing conditions are determined so that the tensile strength after annealing is 425 to 675 MPa.

Specifically, when the sample temperature measured at the thermocouple reaches 900 DEG C in the step (2), the sample is taken out from the furnace and cooled. Specifically, for example, the sample is suspended in a wire in a furnace, By cutting the wire at a point of time when the temperature reaches 900 DEG C and dropping it in a water tank provided below, or by a method in which the sample is rapidly taken out from the furnace immediately after the sample temperature reaches 900 DEG C and immersed in a water bath Conduct.

After the annealing, the second cold rolling is performed so that the degree of processing R is 7 to 50% prior to the solution treatment. The processing degree R (%)

R = (t ₀ - t) / t ₀ 100

(t _0: plate thickness before rolling, t: plate thickness after rolling)

.

If the processing degree R deviates from this range, the area ratio of the Cube orientation becomes less than 5%.

Further, in order to control the value of n to 0.2 or less, the deformation speed of the third cold rolling is controlled to be 1 x 10 ^-4 (1 / sec) or less. The deformation rate of the present invention is specified as the rolling speed / roll contact arc length. In order to lower the deformation rate, it is effective to decrease the rolling speed or to increase the number of pass passes to increase the roll contact arc length. The lower limit of the deformation rate is not limited in terms of the value of n, but rolling is performed at a rate lower than 1 x 10 ^-5 (1 / sec), which is industrially undesirable because of the long rolling time. The deformation rate of rolling in general industry is about 2 x 10 ^-4 to 5 x 10 ^-4 (1 / sec).

The process for producing the alloy according to the present invention is as follows in the order of the process.

(1) Casting of ingots

(2) Hot rolling (at a temperature of 800 to 1000 占 폚 and a thickness of about 5 to 20 mm)

(3) Cold rolling (30 to 99% of processing degree)

(4) Preliminary annealing (softening degree S = 0.25 to 0.75)

(5) Light rolling (7 to 50% processing)

(6) Solution treatment (700 to 900 ° C for 5 to 300 seconds)

(7) Cold rolling (processing degree is 1 to 60%, deformation speed is 1 × 10 ^-4 (1 / sec) or less)

(8) Aging treatment (2 ~ 20 hours at 350 ~ 550 ℃)

(9) Cold rolling (processing degree is 1 to 50%, deformation speed is 1 x 10 ^-4 (1 / sec) or less)

(10) Deformation removal annealing (at a temperature of 300 to 700 ° C for 5 seconds to 10 hours)

Here, the degree of working of cold-rolled (3) is preferably 30 to 99%. In order to partially recrystallize the preliminary annealing 4, it is necessary to introduce deformation in the cold rolling 3, and effective deformation is obtained at a processing degree of 30% or more. On the other hand, if the degree of processing exceeds 99%, cracks may be generated on the edge of the rolled material, and the material during rolling may be broken.

Cold rolling (7) and (9) are carried out arbitrarily for the purpose of high strength and control of the value of n, and the strength is increased while the rolling process degree is increased, while the bendability is decreased. The effects of the present invention are obtained regardless of the degree of processing of the cold rolling (7) and (9). However, it is not preferable from the viewpoint of bending property that the degree of processing in each of the cold rolling (7) and (9) exceeds the upper limit value, and the degree of processing is lower than the lower limit value, not. In order to control the value of n, it is necessary to perform cold rolling at least one of cold rolling (7) and cold rolling (9).

The deformation removing annealing 10 is carried out arbitrarily in order to recover the spring limit value or the like which is lowered by the cold rolling in the case of cold rolling 9. The effect of the present invention is obtained regardless of the presence or absence of the deformation removing annealing 10. [ Deformation removal annealing 10 may or may not be performed.

For the steps (2), (6), and (8), a general manufacturing condition of a Cu-Ni-Si alloy may be selected.

The Cu-Ni-Si based alloy according to the present invention can be processed into various kinds of new products, for example, plates, rods, and foils. The Cu- , Terminals, relays, switches, and foil for secondary batteries.

The final thickness (product thickness) of the Cu-Ni-Si alloy according to the present invention is not particularly limited, but is generally 0.05 to 1.0 mm in the case of the product application.

Example

Examples of the present invention will be described below with reference to comparative examples, but these examples are provided to better understand the present invention and its advantages, and are not intended to limit the invention.

(Example 1)

An alloy containing 2.6% by mass of Ni, 0.58% by mass of Si, 0.5% by mass of Sn and 0.4% by mass of Zn and the balance of copper and inevitable impurities was used as an experimental material, and preliminary annealing, The effects of the degree of processing of the rolling, the deformation rate of the third cold rolling, the crystal orientation and the n value, and further, the crystal orientation and the n value, on the bending properties of the product were examined.

In a high-frequency melting furnace, 2.5 kg of electric copper was dissolved in an argon atmosphere using a graphite crucible having an inner diameter of 60 mm and a depth of 200 mm. An alloy element was added so that the alloy composition was obtained, the molten metal temperature was adjusted to 1300 캜, and a molten metal was injected into the cast iron mold to prepare an ingot having a thickness of 30 mm, a width of 60 mm and a length of 120 mm. The ingot was heated at 950 占 폚 for 3 hours and hot-rolled to a thickness of 10 mm. The oxide scale on the surface of the hot-rolled plate was ground by a grinder and removed. The thickness after grinding was 9 mm. Thereafter, rolling and heat treatment were carried out in the following process order to prepare a product sample having a thickness of 0.15 mm.

(1) Cold rolling to a predetermined thickness according to the rolling process of the first cold rolling and the second cold rolling.

(2) Preliminary annealing: Two methods of inserting a sample into an electric furnace adjusted to a predetermined temperature, holding the sample for a predetermined time, cooling the sample (cooling) by putting the sample in a water bath, or allowing the sample to stand in the air to cool Lt; / RTI &gt;

(3) Second cold rolling: Cold rolling was carried out to various thicknesses of 0.18 mm in thickness by various rolling processes.

(4) Solution treatment: A sample was inserted into an electric furnace adjusted to 800 DEG C and held for 10 seconds, and then the sample was placed in a water bath and cooled.

(5) Aging treatment: Heating was carried out in an Ar atmosphere at 450 캜 for 5 hours using an electric furnace.

(6) Third cold rolling: Cold-rolled at various deformation rates from 0.18 mm to 0.15 mm at a processing rate of 17%.

(7) Deformation removal annealing: A sample was inserted into an electric furnace adjusted to 400 DEG C, held for 10 seconds, and left to stand in the atmosphere for cooling.

The following evaluations were carried out on the sample after the pre-annealing and the product sample (in this case, the deformation annealing was completed).

(Softness evaluation in preliminary annealing)

The tensile strength of the specimen before and after the pre-annealing was measured in parallel with the rolling direction in accordance with JIS Z 2241 using a tensile tester, and the respective values were defined as? ₀ and?. The 900 占 폚 annealing sample was prepared in the above procedure (inserted into the furnace at 950 占 폚 and cooled when the sample reached 900 占 폚), and the tensile strength was measured in parallel with the rolling direction to obtain? ₉₀₀ . From the values of σ ₀ , σ, and σ ₉₀₀ , softening degree S was requested by the following equation.

S = (? _{0 -} ?) / (? _{0 -} ? ₉₀₀ )

(Measurement of crystal orientation of product)

The area ratio of Cube orientation, Copper orientation and Brass orientation was measured by Electron Back-Scatter Diffraction (EBSD).

In the EBSD measurement, a sample area of 500 μm square containing 200 or more crystal grains was scanned at a step of 0.5 μm and the orientation was analyzed. With regard to the deviation angle from the ideal azimuth, the rotation angle was calculated around the common rotation axis to obtain the deviation angle. For example, with respect to the S orientation (2 3 1) [6 -4 3], (1 2 1) [1 -1 1] is rotated by 19.4 ° with the (20 10 17) , And this angle was regarded as a deviation angle. And the common rotation axis can be expressed by the smallest shift angle. This deviation angle was calculated for all the measurement points, and the area of the crystal grains having an orientation up to 10 degrees from each of the Cube orientation, Copper orientation and Brass orientation was regarded as an effective number up to one decimal place, . The information obtained from the orientation analysis by the EBSD includes orientation information up to a depth of several tens of nm at which the electron beam enters the sample, but is described as the area ratio because it is small enough for the area to be measured.

(Tensile test of the product)

A tensile test was carried out using a tensile tester in parallel with the rolling direction in accordance with JIS Z 2241 to obtain a stress-strain curve. Tensile strength and 0.2% proof stress were obtained from this curve. Also, the stress-strain curves were converted to true stress-strain curves and n values were read.

(Bending test of the product)

The minimum bending radius (MBR, unit: mm) at which cracking does not occur when the W bending test described in JIS H 3130 is performed in a direction parallel to the rolling direction is determined and the ratio of the plate thickness (t, unit: mm) MBR / t) was measured.

Table 1 shows test conditions and evaluation results. The inventive example is manufactured under the conditions specified by the present invention, and the crystal orientation and n value satisfy the requirements of the present invention, and MBR / t is 0.5 or less, whereby good bending workability is obtained.

In Comparative Example 1, since the degree of softening in the preliminary annealing was less than 0.25, the area ratio of the copper orientation exceeded 20% and the area ratio of the Cube orientation became less than 5%. In Comparative Example 2, since the degree of softening in the preliminary annealing exceeded 0.75, the area ratio of the Brass orientation exceeded 20% and the area ratio of the Cube orientation became less than 5%. In Comparative Examples 3 and 4, the degree of processing of the second rolling was deviated from the specification of the present invention, and the area ratio of the Cube orientation was less than 5%. In Comparative Example 5, the deformation rate of the third rolling was deviated from the specification of the present invention, and the value of n exceeded 0.2. In the above comparative example, MBR / t was 1, and bending workability was bad.

In addition, Comparative Example 5 was carried out within the range of the conditions recommended by Patent Document 3, and its crystal orientation satisfied the requirements of Patent Document 2.

(Example 2)

It was examined whether the improvement effect of the bending property shown in Example 1 can be obtained also in Cu-Ni-Si based alloys with different components and manufacturing conditions.

Casting, hot rolling and surface grinding were carried out in the same manner as in Example 1 to obtain a plate having a thickness of 9 mm and having the components shown in Table 2. This plate was subjected to rolling and heat treatment in the following process order to prepare a product sample having a plate thickness of 0.15 mm.

(1) Cold rolling to a predetermined thickness according to the rolling process of the first cold rolling and the second cold rolling.

(2) Preliminary annealing: Two methods of inserting a sample into an electric furnace adjusted to a predetermined temperature and keeping it for a predetermined time, cooling the sample (cooling) by putting the sample into a water bath, or allowing the sample to stand in the air to cool Lt; / RTI &gt;

(3) Second cold rolling: Cold rolling was carried out to various thicknesses of 0.18 mm in thickness by various rolling processes.

(4) Solution treatment: A sample was inserted into an electric furnace adjusted to a predetermined temperature and held for 10 seconds, and then the sample was placed in a water bath and cooled. The temperature was selected so that the average diameter of recrystallized grains was in the range of 5 to 25 mu m.

(5) Aging treatment: Heating was carried out in an Ar atmosphere at a predetermined temperature for 5 hours using an electric furnace. The temperature was chosen so that the tensile strength after aging was at a maximum.

(6) Third cold rolling: Cold-rolled at various deformation rates from 0.18 mm to 0.15 mm at a processing rate of 17%.

(7) Deformation removal annealing: After inserting a sample into an electric furnace adjusted to a predetermined temperature and holding it for 10 seconds, the sample was allowed to stand in the air and cooled.

The samples and the product samples after the pre-annealing were evaluated in the same manner as in Example 1. Tables 2 and 3 show test conditions and evaluation results, respectively. In the case where deformation removal annealing was not performed, "no" was marked in the column of the temperature.

The alloy of the present invention contains Ni and Si at the concentrations specified by the present invention and is produced under the conditions specified by the present invention. When the crystal orientation and n value satisfy the requirements of the present invention and MBR / t is 0.5 or less Good bending workability was obtained.

On the other hand, in Comparative Example 6, since the deformation rate of the third rolling was out of the specification of the present invention, the n value exceeded 0.2, and the bending workability was bad. In Comparative Examples 7, 8 and 9, since the degree of softening in the preliminary annealing is out of the specification of the present invention, in Comparative Examples 10 and 11, since the degree of processing of the second rolling is out of the specification of the present invention, The bending workability was bad, deviating from the specification of the present invention. In Comparative Example 12, the Ni and Si concentrations were lower than those of the present invention, and the bending workability was good, but the 0.2% proof strength did not reach 500 MPa.

Claims (6)

1.0 to 4.5% by mass of Ni and 0.2 to 1.0% by mass of Si, and the balance of copper and inevitable impurities, and subjected to EBSD (Electron Back-Scatter Diffraction) The area ratio of the Cube orientation {0 0 1} <1 0 0> is not less than 5%, the area ratio of the Brass orientation {1 1 0} <1 1 2> is not more than 20% } A Cu-Ni-Si alloy having an area ratio of <1 1 1> of 20% or less and a work hardening index of 0.2 or less. The method according to claim 1,
Cu-Ni-Si alloy containing 0.005 to 2.5 mass% of at least one of Sn, Zn, Mg, Fe, Ti, Zr, Cr, Al, P, Mn, Co, Cr and Ag in a total amount. An ingot containing 1.0 to 4.5 mass% of Ni and 0.2 to 1.0 mass% of Si and the balance of copper and inevitable impurities was prepared. The ingot was hot-rolled, then cold-rolled, To 0.75, followed by cold rolling at a working rate of 7 to 50%, followed by solution treatment, followed by cold rolling at an aging treatment and a deformation rate of 1 x 10 &lt; ^-4 &gt; (1 / sec) The method for producing a Cu-Ni-Si based alloy according to any one of claims 1 to 3, which is carried out in an arbitrary order. The method of claim 3,
Wherein the ingot is a Cu-Ni-Si alloy containing 0.005 to 2.5 mass% of at least one of Sn, Zn, Mg, Fe, Ti, Zr, Cr, Al, P, Mn, Gt; A novelty product comprising the copper alloy according to any one of claims 1 to 3. An electronic device part having the copper alloy according to claim 1 or 2.

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