TWI494450B - Carbene alloy and its manufacturing method - Google Patents

Description

Carson alloy and its manufacturing method

The present invention relates to a Carson alloy having a conductive spring material suitable for use as a connector, a terminal, a relay, a switch, or the like, or a lead wire for a semiconductor device such as an integrated circuit (IC). The frame material has excellent strength, bending workability, stress relaxation resistance, and electrical conductivity.

In recent years, with the miniaturization of electrical and electronic components, the copper alloy used for these components requires good strength, electrical conductivity, and bending workability. It is required to increase the demand for precipitation-strengthened copper alloys such as Carson alloys having high strength and electrical conductivity in place of the solid solution-strengthened copper alloys such as phosphor bronze or brass. The Carson alloy is an alloy obtained by depositing an intermetallic compound such as Ni-Si, Co-Si, or Ni-Co-Si in a Cu matrix, and has high strength, high electrical conductivity, and good bending workability. In general, the strength and bending workability are opposite, and it is expected that the Carson alloy maintains high strength and improves bending workability.

When the copper alloy sheet is press-formed into an electrical or electronic component such as a connector, in order to improve the dimensional accuracy of the bent portion, the surface of the copper alloy sheet may be subjected to a slit process called a notch process in advance, and may be bent along the slit. Copper alloy plate (hereinafter also referred to as notched bending). This notch bending is often used, for example, for press working of a female terminal for a vehicle. The copper alloy is hardened by the notch processing and loses ductility, so the copper alloy is prone to cracking in the subsequent bending process. Therefore, it is especially required for copper alloys used for notch bending. Has good bending processability.

In recent years, as a technique for improving the bendability of the Caston alloy, a method of controlling the area ratio of the Cube orientation ({001}<100>) has been proposed. For example, in Patent Document 1 (JP-A-2006-283059), (1) casting, (2) hot rolling, (3) cold rolling (processing degree: 95% or more), and (4) solid solution are sequentially performed. Treatment, (5) cold rolling (degree of processing is 20% or less), (6) ageing treatment, (7) cold rolling (processing degree: 1 to 20%), (8) short-time annealing step, The area ratio of the Cube orientation is controlled to 50% or more, thereby improving the bending workability.

Further, in Patent Document 2 (JP-A-2010-275622), (1) casting, (2) hot rolling (the temperature is lowered from 950 ° C to 400 ° C), and (3) cold rolling are sequentially performed. (Processing degree is 50% or more), (4) Intermediate annealing (conductivity is adjusted to 1.5 times or more at 450 to 600 ° C, and hardness is adjusted to 0.8 times or less), (5) Cold rolling (processing degree is 70%) Above), (6) solution treatment, (7) cold rolling (working degree 0 to 50%), (8) aging treatment, and {200} (synonymous with {001}) X-ray diffraction intensity control The X-ray diffraction intensity of the copper powder standard sample is improved to improve the bending workability.

Further, in Patent Document 3 (JP-A-2011-17072), the area ratio of the Cube orientation is controlled to 5 to 60%, and the area ratios of the Brass orientation and the Copper orientation are controlled to 20% or less, thereby improving the bending process. Sex. For this manufacturing step, (1) casting, (2) hot rolling, (3) cold rolling (processing degree: 85 to 99%), and (4) heat (5 minutes to 20 hours at 300~700°C), (5) cold rolling (5~35% processing), (6) solution treatment, (7) aging treatment, (8) cold rolling (processing) The best bendability is obtained when the degree is 2 to 30%) and (9) the step of quenching and tempering.

On the other hand, in Patent Document 4 (WO2011/068126), the bending workability is improved by reducing the (111) plane toward the width direction instead of controlling the Cube orientation. The manufacturing steps for this are proposed by (1) casting, (2) hot rolling (water cooling after processing 30 to 98% at 500 to 1020 °C), and (3) cold rolling (processing degree is 50 to 99%). (4) Intermediate heat treatment (maintaining 10 to 5 minutes at 600 to 900 ° C to become uneven recrystallized structure), (5) cold rolling (degree of processing is 5 to 55%), and (6) intermediate recrystallization heat treatment (maintained at a temperature lower than the solute solution temperature by 10 to 200 ° C for 1 second to 20 hours to become a recrystallized structure), and (7) solution treatment (for a temperature of 10 to 150 ° C higher than the solute solution temperature for 1 second) ~10 minutes), (8) aging treatment, (9) cold rolling (degree of processing 2 to 45%), (10) steps of quenching and tempering.

[Patent Document 1] Japanese Patent Laid-Open Publication No. 2006-283059

[Patent Document 2] Japanese Patent Laid-Open Publication No. 2010-275622

[Patent Document 3] Japanese Patent Laid-Open Publication No. 2011-17072

[Patent Document 4] WO2011/068126

The inventors conducted a verification test on the effects of the above prior invention. As a result, when the bending workability was evaluated by the W bending test, a certain improvement effect was observed. However, for the notch bending, it is impossible to obtain sufficient Bending workability. Accordingly, an object of the present invention is to provide a Carson alloy having both high strength and high notch bendability and a method for producing the same.

In the prior art, for example, the crystal orientation of the copper alloy was analyzed by the EBSD method, and the characteristics of the copper alloy were improved based on the obtained data. Here, EBSD (Electron Back Scatter Diffraction) is a reflection electron electron mirror line diffraction generated when an electron beam is irradiated to a sample in an SEM (Scanning Electron Microscope) ( The technique of analyzing the crystal orientation by the Kikuchi pattern). Generally, the information obtained when the electron beam is irradiated onto the surface of the copper alloy is that the electron beam intrudes into the azimuth information of the depth of 10 nm, that is, the orientation information of the surface layer.

On the other hand, the inventors have found that it is necessary to control the crystal orientation of the inside of the copper alloy sheet for the notch bending. The reason for this is that the inner corner of the bend moves toward the inside of the panel due to the notch processing. Further, the crystal orientation of the central portion in the thickness direction is curved with respect to the notch, and the manufacturing method for obtaining the crystal orientation is clarified.

The present invention, which is completed in the context of the above findings, is a Carson alloy which contains one or more of Ni and Co: 0.8 to 5.0% by mass, Si: 0.2 to 1.5% by mass, and the balance is copper and The rolled material composed of the unavoidable impurities is aligned with the Cube orientation when the EBSD measurement is performed in parallel with the thickness direction of the center portion in the thickness direction of the cross-sectional position of 45 to 55% of the sheet thickness. The area ratio of the crystal of 001}<100> is 5% or more, and the area ratio of the crystal in the width direction (TD) of the rolled material in the <111> direction is 50% or less.

In one embodiment, the Carson alloy of the present invention is relative to the thickness of the plate. When the EBSD measurement is performed in parallel with the thickness direction of the center portion of the 45 to 55% cross-sectional position and the crystal orientation is analyzed, the area ratio of the crystals oriented to the Cube orientation {001}<100> is 5 to 70%. .

In another embodiment, the Carson alloy of the present invention contains 0.005 to 3.0% by mass of total of Sn, Zn, Mg, Fe, Ti, Zr, Cr, Al, P, Mn, Co, Cr, and Ag. One or more of them.

In still another embodiment of the Carson alloy of the present invention, the bending deformation coefficient in the rolling direction is 106 to 119 GPa.

Further, in another aspect of the invention, a method for producing a Carson alloy is provided, which comprises one or more of Ni and Co: 0.8 to 5.0% by mass, Si: 0.2 to 1.5% by mass, and the balance being copper and not An ingot composed of impurities is subjected to hot rolling at a temperature of 800 to 1000 ° C to adjust the thickness to 5 to 20 mm, and the conductivity is adjusted to 30% IACS or more, followed by The processing degree is 30~99.5% cold rolling, softening degree is 0.20~0.80, pre-annealing, processing degree is 3~50% cold rolling, 700~950°C 5~300 seconds solution treatment, processing degree is 0~60% cold rolling, aging treatment at 350~600 °C for 2~20 hours, processing degree is 0~50% cold rolling; wherein softness is set to S, the following formula indicates the above softness: S= (σ ₀ -σ)/(σ ₀ -σ ₉₅₀ )

(here, σ ₀ is the tensile strength before pre-annealing, and σ and σ ₉₅₀ are tensile strengths after pre-annealing and annealing at 950 ° C, respectively).

In a preferred embodiment of the method for producing a Carson alloy according to the present invention, the ingot contains 0.005 to 3.0% by mass of Sn, Zn, and Mg, based on the total amount. One or more of Fe, Ti, Zr, Cr, Al, P, Mn, Co, Cr, and Ag.

In another aspect of the invention, there is provided a copper-clad product having the above-described Carson alloy.

In another aspect, the invention is an electronic machine component provided with the above-described Carson alloy.

According to the present invention, a Carson alloy having both high strength and high notch bending property and a method for producing the same can be provided.

(addition of Ni, Co and Si)

Ni, Co, and Si are precipitated as an intermetallic compound such as Ni-Si, Co-Si, or Ni-Co-Si by performing an appropriate aging treatment. By the action of the precipitate, the strength is increased, and Ni, Co, and Si which are dissolved in the Cu matrix are reduced by precipitation, and thus the electrical conductivity is improved. However, if the total amount of Ni and Co is less than 0.8% by mass or Si is less than 0.2% by mass, the desired strength cannot be obtained. On the other hand, if the total amount of Ni and Co exceeds 5.0% by mass or Si exceeds 1.5% by mass, Then, the notch bendability is remarkably deteriorated. Therefore, in the Carson alloy of the present invention, the addition amount of one or more of Ni and Co is set to 0.8 to 5.0% by mass, and the addition amount of Si is set to 0.2 to 1.5% by mass. The addition amount of one or more of Ni and Co is preferably 1.0 to 4.0% by mass, and the addition amount of Si is more preferably 0.25 to 0.90% by mass.

(other added elements)

Sn, Zn, Mg, Fe, Ti, Zr, Cr, Al, P, Mn, Co, Cr, and Ag contribute to the improvement of strength. Further, Zn is resistant to heat removal of Sn plating The improvement of the effectiveness is effective, and Mg is effective for improving the stress relaxation property, and Zr, Cr, and Mn are effective for improving the hot workability. If the total amount of Sn, Zn, Mg, Fe, Ti, Zr, Cr, Al, P, Mn, Co, Cr, and Ag is less than 0.005% by mass, the above effect cannot be obtained, and if it exceeds 3.0% by mass, the notch is bent. Significantly reduced sex. Therefore, in the Carson alloy of the present invention, it is preferred to contain the elements in an amount of 0.005 to 3.0% by mass, more preferably 0.01 to 2.5% by mass based on the total amount.

(crystal orientation)

If the Cube orientation is increased, uneven deformation is suppressed and the bendability is improved. Here, the Cube orientation refers to a state in which the (001) plane faces the normal direction (ND) of the rolling surface and the (100) plane faces the rolling direction (RD), and is expressed by an index of {001}<100>.

If the area ratio of the Cube orientation in the central portion of the thickness is less than 5%, the notch bending property is drastically lowered. Therefore, the area ratio of the crystal of the Cube orientation which is aligned to the central portion of the thickness is 5% or more, and more preferably 10% or more.

The upper limit of the area ratio of the crystal of the Cube orientation of the center portion of the sheet thickness is not particularly limited in terms of the notch curvature of the object of the present invention. However, if the Cube azimuth area ratio in the central portion of the plate thickness exceeds 70%, the bending deformation coefficient is remarkably lowered. When the bending deformation coefficient is lowered, when the connector is processed into a connector, sufficient contact force at the contact is not obtained, and the contact resistance is increased. Therefore, the Cube azimuth area ratio is preferably 70% or less. When the Cube azimuth area ratio is controlled to 70% or less, a sufficiently high bending deformation coefficient of 116 GPa or more can be obtained. Carson alloy of the invention The bending deformation coefficient is typically 106 to 119 GPa.

In addition to the above-described control of the Cube orientation, the crystallization of the width direction of the alloy rolled material of the present invention (the method perpendicular to ND and RD, hereinafter referred to as TD) for the <111> direction can be made by the center portion of the plate thickness The area ratio is controlled to be 50% or less, and more preferably controlled to 30% or less, which makes it possible to bend the notch.

The lower limit of the area ratio of the TD crystal in the <111> direction of the central portion of the plate thickness is not limited in terms of the notch bending property, but the area ratio is not reached in the alloy of the present invention produced under the following conditions. 1% is less.

Here, the central portion of the plate thickness means a cross-sectional position of 45 to 55% with respect to the thickness of the plate.

(Production method)

In the general manufacturing process of the Carson alloy, first, electrolytic copper, Ni, Co, Si, and the like are melted in a melting furnace to obtain a melt of a desired composition. The melt is then cast into an ingot. Thereafter, it is processed into a strip or foil having a desired thickness and characteristics in the order of hot calendering, cold calendering, solution treatment, and aging treatment. After the heat treatment, in order to remove the surface oxide film formed during the heat treatment, pickling or polishing of the surface may be performed. Further, in order to increase the strength, cold rolling may be performed between the solution treatment and the aging or after the aging.

In the present invention, in order to obtain the crystal orientation described above, heat treatment (hereinafter also referred to as pre-annealing) and cold rolling (hereinafter also referred to as light calendering) with a relatively low degree of work are performed before the solution treatment, and further, after the hot rolling is completed Conductivity Adjust to a specific range.

Pre-annealing is performed in order to form a recrystallized grain portion in a rolled structure formed by cold rolling after hot rolling. The proportion of recrystallized grains in the calendered structure has an optimum value, and the above crystal orientation cannot be obtained with too little or too much. The optimum ratio of recrystallized grains is obtained by adjusting the pre-annealing conditions so that the softening degree S defined below becomes 0.20 to 0.80.

The relationship between the annealing temperature and the tensile strength of the alloy of the present invention when annealed at various temperatures is illustrated in FIG. A sample in which a thermocouple was attached was inserted into a tubular furnace at 1000 ° C, and when the temperature of the sample measured by the thermocouple reached a specific temperature, the sample was taken out from the furnace and water-cooled to measure the tensile strength. The sample is recrystallized at a limit temperature of 500 to 700 ° C, and the tensile strength is rapidly lowered. The slow decrease in tensile strength on the high temperature side is caused by the growth of recrystallized grains.

The softness S in the pre-annealing is defined according to the following formula.

S=(σ ₀ -σ)/(σ ₀ -σ ₉₅₀ )

Here, σ ₀ is the tensile strength before annealing, and σ and σ ₉₅₀ are tensile strengths after pre-annealing and annealing at 950 ° C, respectively. When the alloy of the present invention is annealed at 950 ° C, it can be stably completely recrystallized, so that a temperature of 950 ° C is used as a reference temperature for knowing the tensile strength after recrystallization.

When S is less than 0.20, the area ratio of the Cube orientation in the center portion of the sheet thickness is less than 5%, and the area ratio of the crystal in the <111> direction to the TD is increased.

When S exceeds 0.80, the area ratio of the Cube orientation in the center portion of the sheet thickness is less than 5%, and the area ratio of the crystal in the <111> direction to the TD is increased.

The temperature and time of pre-annealing are not particularly limited. It is important to adjust the S Into the above range. Generally, in the case of using a continuous annealing furnace, the furnace temperature is 400 to 750 ° C for 5 seconds to 10 minutes, and when the batch annealing furnace is used, the furnace temperature is 350 to 600 ° C for 30 minutes. ~20 hours range.

Furthermore, the setting of the pre-annealing conditions can be performed by the following sequence.

(1) The tensile strength (σ ₀ ) of the material before pre-annealing was measured.

(2) The material before pre-annealing was annealed at 950 °C. Specifically, the material to which the thermocouple was attached was inserted into a tubular furnace at 1000 ° C, and when the temperature of the sample measured by the thermocouple reached 950 ° C, the sample was taken out from the furnace and water-cooled.

(3) The tensile strength (σ ₉₅₀ ) of the material after annealing at 950 ° C was determined.

(4) For example, when σ ₀ is 800 MPa and σ ₉₅₀ is 300 MPa, the tensile strengths corresponding to the softening degrees of 0.20 and 0.80 are 700 MPa and 400 MPa, respectively.

(5) The conditions of the pre-annealing were determined so that the tensile strength after annealing became 400 to 700 MPa.

After the pre-annealing described above, a light calendering degree of 3 to 50% is performed before the solution treatment. The degree of processing R (%) is defined by the following formula.

R=(t ₀ -t)/t ₀ ×100 (t ₀ : plate thickness before rolling, t: plate thickness after rolling)

If the degree of processing exceeds this range, the Cube azimuth area ratio is less than 5%, and the area ratio of the crystals in the <111> direction aligned with TD also increases.

In addition to the above-described pre-annealing and light calendering, the conductivity after the end of hot rolling can be adjusted to 30% IACS or more, and more preferably adjusted to 32% IACS or more to obtain the crystal orientation of the present invention. If the conductivity is less than 30% IACS, the Cube azimuth area ratio is less than 5%, and the area ratio of the crystallization of the TD in the <111> direction increases.

The usual calendering of the Carson alloy is carried out under the conditions of solid solution of Ni, Co and Si (solid solution in Cu) in order to reduce the load during subsequent solution heat treatment. Therefore, the electrical conductivity of the Carson alloy after the usual hot rolling is about 25% IACS. In order to solid-dissolve Ni, Co, and Si, it is necessary to suppress precipitation of Ni-Si, Co-Si, Ni-Co-Si, etc. at the time of cooling after completion of hot rolling, so that the material after hot rolling is water-cooled or the like. Irritable cooling.

The present invention is intended to precipitate Ni, Co, and Si as much as possible in hot rolling, and to heat the ingot heated to 800 to 1000 ° C to a thickness of 5 to 20 mm, for example, by air cooling or the like, thereby slowly cooling. The above conductivity can be obtained. The hot rolled material can be immediately inserted into a heat-insulating container, heated by a burner, or inserted into a heating furnace to be cooled in the furnace, and the cooling can be actively delayed, thereby further promoting the precipitation of Ni, Co, and Si. . However, if the conductivity is increased above 50% IACS, the cooling takes a long time and the production efficiency is extremely lowered. Therefore, it is preferable to set the upper limit of the conductivity to 50% IACS. Further, the conductivity is more preferably less than 40% in terms of controlling the Cube azimuth area ratio at the central portion of the thickness to 70% or less.

If the manufacturing method of the alloy of the present invention is listed in the order of the steps, it is as follows.

(1) Casting of ingots (thickness 20~300mm)

(2) Hot rolling (temperature to 800~1000 °C, thickness to 5~ 20mm, conductivity is 30% IACS or more)

(3) Cold rolling (processing degree is 30~99.5%)

(4) Pre-annealing (softening degree: S=0.20~0.80)

(5) Light rolling (processing degree is 3~50%)

(6) Solution treatment (5~300 seconds at 700~950°C)

(7) Cold rolling (processing degree is 0~60%)

(8) Aging treatment (2~20 hours at 350~600°C)

(9) Cold rolling (processing degree is 0~50%)

(10) Strain annealing (5 to 10 hours at 300~700 °C)

Here, the degree of processing of the cold rolling (3) is preferably set to 30 to 99.5%. In order to partially form the recrystallized grains in the pre-annealing (4), it is necessary to introduce strain into the cold rolling (3), and an effective strain can be obtained by using a working degree of 30% or more. On the other hand, when the degree of work exceeds 99.5%, cracking occurs at the edge of the rolled material or the like, and the material in the rolling is broken.

Cold rolling (7) and (9) are arbitrarily carried out in order to achieve high strength. However, there is a tendency that the strength increases as the degree of calendering increases, and on the other hand, the area ratio of the crystals in the <111> direction aligned with TD increases, and the Cube azimuth area ratio decreases. When the degree of processing of each of the cold rollings (7) and (9) exceeds the above upper limit value, the area ratio of the crystal in the <111> direction of the center portion of the sheet thickness to the TD exceeds the specification of the present invention, and when the notch is bent There will be a break.

Strain annealing (10) is for the case of cold rolling (9) In the case where the elastic limit value which is lowered by the cold rolling is restored, it is arbitrarily performed. The effect of the present invention in which the notch bendability is improved by controlling the crystal orientation of the central portion of the thickness of the sheet can be obtained with or without strain relief annealing (10). The strain relief annealing (10) may or may not be performed.

Further, in the steps (6) and (8), the general manufacturing conditions of the Carson alloy may be selected.

The Carson alloy of the invention can be processed into various copper products, such as plates, strips and foils, and the Carson alloy of the invention can be used for lead frames, connectors, pins, terminals, relays, switches, foils for secondary batteries Such as electronic machine parts and so on.

[Examples]

In the following, the embodiments and comparative examples of the present invention are disclosed, but the embodiments are provided to more fully understand the present invention and its advantages, and are not intended to limit the present invention.

(Example 1)

Pre-annealing conditions and light calendering were studied using an alloy containing Ni: 2.6 mass%, Si: 0.58 mass%, Sn: 0.5 mass%, and Zn: 0.4 mass%, and the remainder consisting of copper and unavoidable impurities as experimental materials. The relationship between the electrical conductivity and the crystal orientation after the end of the hot rolling, and the influence of the crystal orientation on the bendability and mechanical properties of the product.

In a high-frequency melting furnace, a graphite crucible having an inner diameter of 60 mm and a depth of 200 mm was used to melt 2.5 kg of electrolytic copper in an argon atmosphere. The alloying element is added in such a manner that the above alloy composition can be obtained, the temperature of the melt is adjusted to 1300 ° C, and then cast into a mold made of cast iron to produce a thickness of 30 mm. An ingot having a width of 60 mm and a length of 120 mm. Thereafter, the ingot was processed in the following procedure, and a product sample having a thickness of 0.15 mm was produced.

(1) Hot rolling: The ingot was heated at 950 ° C for 3 hours and calendered to a thickness of 10 mm. In order to change the conductivity after the end of the hot rolling, the calendered material is immediately cooled by the following three methods.

(A) Put into the water tank (water-cooled).

(B) placed in the atmosphere (air cooled).

(C) After being inserted into an electric furnace heated to 300 ° C or 400 ° C, the furnace is turned off and cooled in the furnace (cooling in the furnace).

(2) Grinding: The scale formed by hot calendering was removed by a grinder. The thickness after grinding was 9 mm.

(3) Cold rolling: cold rolling to a specific thickness according to the calendering degree of light rolling.

(4) Pre-annealing: After inserting a sample into an electric furnace adjusted to a specific temperature and holding it for a certain period of time, the sample is placed in a water tank for cooling.

(5) Light calendering: cold rolling was performed at various calendering degrees until the thickness became 0.18 mm.

(6) Solution treatment: The sample was inserted into an electric furnace adjusted to 800 ° C and held for 10 seconds, and then the sample was placed in a water bath to be cooled. The crystal grain size after the solution treatment was about 10 μm.

(7) Aging treatment: heating in an electric furnace at 450 ° C for 5 hours in an argon atmosphere.

(8) Cold rolling: cold rolling from 0.18mm to 17% processing degree 0.15mm.

(9) Strain annealing: The sample was inserted into an electric furnace adjusted to 400 ° C, and after holding for 10 seconds, the sample was placed in the atmosphere and cooled.

The sample after hot rolling, the sample after pre-annealing, and the sample of the product (in this case, the end of strain relief annealing) were evaluated as follows.

(Measurement of electrical conductivity after hot rolling)

The surface of the sample after hot rolling was mechanically ground to remove the scale and planarize it. Conductivity was measured at a frequency of 60 kHz using SIGMATEST D2.068 manufactured by FOERSTER Co., Ltd. on its surface.

(Evaluation of softening degree of pre-annealing)

The tensile strength of each of the samples before pre-annealing and after pre-annealing was measured in parallel with the rolling direction using a tensile tester in accordance with JIS Z 2241, and the respective values were set to σ ₀ and σ, respectively. Further, an annealing sample was produced at 950 ° C in the above-described order (inserted into a furnace at 1000 ° C and water-cooled when the sample reached 950 ° C), and the tensile strength was measured in parallel with the rolling direction to obtain σ ₉₅₀ . The softening degree S is obtained from σ ₀ , σ, and σ ₉₅₀ .

S=(σ ₀ -σ)/(σ ₀ -σ ₉₅₀ )

(Measurement of crystal orientation of products)

The area ratio of the {100}<001> direction in the center portion of the thickness direction and the thickness direction of the plate thickness direction and the area ratio of the TD crystal in the <111> direction were measured.

As a sample for analyzing the crystal orientation of the surface layer, the surface of the sample was mechanically polished to remove fine irregularities generated by a rolled pattern or the like, and then processed into a mirror surface by electrolytic polishing. The depth of the surface The degree is in the range of 2 to 3 μm.

Further, the sample for analyzing the crystal orientation of the central portion of the thickness is removed from one surface to the center portion of the thickness by etching using a ferric chloride solution, and then processed into a mirror surface by mechanical polishing and electrolytic polishing. . The thickness of the processed sample is in the range of 45 to 55% with respect to the original thickness.

In the EBSD measurement, the area of the sample containing 200 or more crystal grains and 500 μm square was scanned in a step of 0.5 μm to measure the crystal orientation distribution. Next, the crystal orientation density function is analyzed, and the area of the region having an orientation difference of 15° or less from the {100}<001> orientation is obtained, and the area is divided by the total measurement area as the "alignment to the Cube orientation {001}< 100>The area ratio of the crystal".

Further, the area of the region in which the angle between the <111> direction of the crystal and the TD is 15° or less is obtained, and the area is divided by the entire measurement area as the area ratio of the crystal of the TD in the <111> direction.

The information obtained by the azimuth analysis performed by EBSD includes the electron beam intrusion into the azimuth information of the sample length of 10 nm, but is described as the area ratio because it is sufficiently small with respect to the measured width.

( tensile test of the product)

The tensile strength was measured in parallel with the rolling direction in accordance with JIS Z 2241 using a tensile tester.

(W bending test of product)

According to JIS H 3100, the inner bending radius was set to t (thickness), and the W bending test was performed in the Good Way direction (the bending axis and the rolling direction were orthogonal). Next, the bending profile is studied by mechanical grinding and polishing. It was ground into a mirror surface and observed by an optical microscope for cracking. The case where no crack was observed was evaluated as ○, and the case where visible cracking was evaluated as ×.

(notch bending test of product)

The test sequence is shown in Figure 2. A notch processing having a depth of 1/2 t is applied to the plate thickness t. The angle of the front end of the notch was set to 90 degrees, and a flat portion having a width of 0.1 mm was set at the front end. Next, according to JIS H 3100, the inner bending radius was set to t, and the W bending test was performed in the Good Way direction (the bending axis and the rolling direction were orthogonal). Next, the curved section was polished by mechanical polishing and polishing to form a mirror surface, and the presence or absence of cracking was observed by an optical microscope. The case where no crack was observed was evaluated as ○, and the case where visible cracking was evaluated as ×.

(Measurement of bending deformation coefficient)

The bending deformation coefficient in the rolling direction is measured in accordance with the JCBA technical standard "Method for Measuring Bending Deformation Coefficient of Cantilever Beam Using Copper and Copper Alloy Strips".

A sample having a short strip shape having a thickness t, a width w (= 10 mm), and a length of 100 mm was obtained in such a manner that the longitudinal direction of the sample was parallel to the rolling direction. One end of the sample was fixed, and a load of P (= 0.15 N) was applied at a position from the fixed end L (= 100 t), and according to the bending d at this time, the Young's modulus E was obtained by the following formula.

E=4×P×(L/t) ³ /(w×d)

The test conditions and evaluation results are shown in Table 1.

Inventive examples 1 to 11 are all pre-annealed, lightly rolled, and hot-rolled under the conditions specified in the present invention, and the crystal orientation of the central portion of the thickness of the sheet satisfies the requirements of the present invention, and is not observed when W is bent or notched. When cracking occurs, a high tensile strength of more than 800 MPa can be obtained. However, in the invention example 11 in which the Cube azimuth area ratio at the central portion of the plate thickness exceeded 70%, the bending deformation coefficient was remarkably lower than that of the other examples. Since such a bending deformation coefficient is lowered when the connector is processed into a connector, the contact force of the contact is lowered, so that the contact force is not preferable.

In Comparative Example 1, since the softening degree in the pre-annealing was less than 0.20, the Cube azimuth area ratio in the central portion of the thickness was less than 5%.

In Comparative Example 2, since the softening degree in the pre-annealing exceeded 0.80, the Cube azimuth area ratio in the central portion of the thickness was less than 5%.

In Comparative Example 3, since the softening degree in the pre-annealing was more than 0.80 and was too large, the Cube azimuth area ratio in the central portion of the thickness was less than 5%, and the area ratio of the TD crystal in the <111> direction of the central portion of the thickness was aligned. More than 50%.

In Comparative Examples 4 and 5, the degree of processing of the light rolling was beyond the specification of the present invention, and the Cube azimuth area ratio at the center portion of the sheet thickness was less than 5%.

In Comparative Example 6, since the conductivity after the end of the hot rolling was less than 30% IACS, the Cube azimuth area ratio at the center portion of the sheet thickness was less than 5%, and the <111> direction at the center portion of the sheet thickness was aligned with the crystallization of TD. The area ratio is over 50%. Further, Comparative Example 6 is manufactured under the conditions recommended by Patent Document 3.

Comparative Example 7 is a manufacturer under the conditions recommended by Patent Document 4. Since the water is cooled immediately after the end of the hot rolling, the electrical conductivity after the end of the hot rolling is not reached. 30% IACS. The pre-annealing is carried out under the condition that the entire surface is not subjected to recrystallization, and the degree of softness is occasionally within the scope of the present invention. The heat treatment was added before the solution treatment, and it was heated at 650 ° C (temperature lower than the solute solid solution temperature of 10 to 200 ° C) for 1 hour to recrystallize. In the same manner as in the other examples, the solution treatment was carried out at 800 ° C (temperature higher than the solute solid solution temperature of 10 to 150 ° C) for 10 seconds. In Comparative Example 7, the area ratio of the crystal in which the <111> direction is aligned with TD is lower than the thickness of the surface layer portion, but is more than 50% in the central portion of the thickness. Further, the Cube azimuth area ratio was not satisfied by 5% in the surface layer portion and the center portion of the sheet thickness.

In the above comparative example, although cracking did not occur at the time of W bending, cracking occurred when the notch was bent.

In Comparative Example 8, after hot rolling and water-cooling, surface polishing was carried out, and rolling was carried out from a thickness of 9 mm to a thickness of 0.18 mm without pre-annealing and light rolling. This step is equivalent to the general manufacturing method of the previous Carson alloy. In the central portion and the surface layer of the plate thickness, the Cube azimuth area ratio is less than 5%, and the area ratio of the <111> direction to the TD crystal is more than 50%. As a result, cracking occurred both when W was bent and when the notch was bent.

(Example 2)

In order to further verify that the center portion of the thickness of the sheet was properly measured as the crystal orientation for controlling the notch bendability, the crystal orientation of the sheet thickness of the samples of Comparative Examples 1 and 3 was measured. That is, after etching by using a ferric chloride solution, the surface is removed from a surface to a depth of 1/4 (0.038 mm), and then processed into a mirror surface by mechanical polishing and electrolytic polishing. The measurement was carried out. As a result, the following values which are very close to the measured values of the surface layer can be obtained:

[Comparative Example 1] Cube: 10%, {111} direction is aligned with TD: 21%

[Comparative Example 3] Cube: 7%, {111} direction is aligned with TD: 19%

From this, it was confirmed that the measurement of the 1/4 position of the sheet thickness could not evaluate the notch bending property, and the measurement of the center portion of the sheet thickness was required.

(Example 3)

In Example 3, it was investigated whether or not the improvement of the notch bending property as shown in Example 1 can be obtained by using a Carson alloy having different compositions and manufacturing conditions.

First, casting was carried out in the same manner as in Example 1 to obtain an ingot having the composition of Table 2.

(1) Hot rolling: The ingot was heated at 950 ° C for 3 hours and calendered to a thickness of 10 mm. The calendered material is immediately cooled by water cooling or air cooling.

(2) Grinding: The scale generated by the hot pressing delay is removed by a grinder. The thickness after grinding was 9 mm.

(3) Cold rolling

(4) Pre-annealing: After inserting a sample into an electric furnace adjusted to a specific temperature and holding it for a certain period of time, the sample is placed in a water tank for cooling.

(5) Light rolling

(6) Solution treatment: The sample was inserted into an electric furnace adjusted to a specific temperature, and after holding for 10 seconds, the sample was placed in a water tank to be cooled. This temperature is selected within a range in which the average diameter of the recrystallized grains is in the range of 5 to 25 μm.

(7) Cold rolling (calendering 1)

(8) Aging treatment: use electric furnace to add in specific temperature and argon atmosphere Heat for 5 hours. This temperature is selected such that the tensile strength after aging is maximized.

(9) Cold rolling (calendering 2)

(10) De-strain annealing: The sample was inserted into an electric furnace adjusted to a specific temperature, and after holding for 10 seconds, the sample was placed in the atmosphere to be cooled.

The same evaluation as in Example 1 was carried out on the sample after hot rolling, the sample after pre-annealing, and the sample of the product. The test conditions and evaluation results are shown in Tables 2 and 3. In the case where any of calendering 1, rolling, and strain relief annealing is not performed, it is referred to as "none" in each of the processing degrees or temperature columns.

Inventive Examples 12 to 29 are all containing Ni, Co, and Si having the concentrations specified in the present invention, and pre-annealing, light rolling, and hot rolling are carried out under the conditions specified in the present invention, and the crystal orientation of the central portion of the thickness of the sheet satisfies the present invention. It is stipulated that the notch can be bent and a high tensile strength exceeding 650 MPa can be obtained.

In Comparative Examples 10 and 17, the degree of processing of the rolling 2 exceeded 50%, and in Comparative Example 11, the degree of processing of the rolling 1 exceeded 60%. In these comparative examples, the crystal orientation of the central portion of the plate thickness exceeded the specifications of the invention, and cracking occurred when the notch was bent.

In Comparative Examples 9 and 16, the degree of processing of the light rolling did not satisfy the requirements of the present invention. In Comparative Examples 12 and 14, the softening degree of the pre-annealing did not satisfy the requirements of the present invention. In Comparative Examples 13 and 15, the electrical conductivity after the end of hot rolling was less than 30% IACS. In the comparative examples, similarly to the alloy of the comparative example of Example 1, the crystal orientation of the central portion of the thickness was exceeded in the specification of the invention, and cracking occurred when the notch was bent.

In Comparative Example 18, the total concentration of Ni and Co and the concentration of Si were lower than the specifications of the present invention, and the notch bending property was good, but the tensile strength was also less than 500 MPa.

In Comparative Example 19, the total concentration of Ni and Co exceeded the specification of the present invention, and the crystal orientation of the central portion of the thickness of the sheet satisfies the requirements of the present invention, but cracks occur when the notch is bent.

Fig. 1 is a graph showing the relationship between the annealing temperature and the tensile strength when the alloy of the present invention is annealed at various temperatures.

Fig. 2 is a view showing a test procedure of a notch bending test in the examples.

Claims (12)

A Carson alloy containing one or more of Ni and Co: 0.8 to 5.0% by mass, Si: 0.2 to 1.5% by mass, and the remainder consisting of a rolled material composed of copper and unavoidable impurities, relative to the thickness of the sheet When the EBSD measurement is performed in parallel with the thickness direction of the center portion in the thickness direction of the 45 to 55% cross-sectional position, and the crystal orientation is analyzed, the area ratio of the crystals oriented to the Cube orientation {001}<100> is 5% or more. Further, the area ratio of the crystal in the width direction (TD) of the rolled material in the <111> direction is 50% or less. For example, the Carson alloy of claim 1 contains 0.005 to 3.0% by mass of total of Sn, Zn, Mg, Fe, Ti, Zr, Cr, Al, P, Mn, Co, Cr and Ag. One or more of them. In the case of the Carson alloy of the first aspect of the invention, in the center portion in the thickness direction of the cross-sectional position of 45 to 55% of the sheet thickness, when the EBSD measurement is performed in parallel with the thickness direction and the crystal orientation is analyzed, The area ratio of the crystals assigned to the Cube orientation {001}<100> is 5 to 70%. For example, the Carson alloy of claim 3 contains 0.005 to 3.0% by mass of total of Sn, Zn, Mg, Fe, Ti, Zr, Cr, Al, P, Mn, Co, Cr and Ag. One or more of them. For example, the Carson alloy of the first application of the patent scope, wherein the bending deformation coefficient of the rolling direction is 106 to 119 GPa. For example, the Carson alloy of claim 2, wherein the bending deformation coefficient in the rolling direction is 106 to 119 GPa. For example, the Carson alloy of the third application patent scope, wherein the bending deformation coefficient of the rolling direction is 106 to 119 GPa. For example, the Carson alloy of the fourth application patent scope, wherein the bending deformation coefficient of the rolling direction is 106 to 119 GPa. A method for producing a Carson alloy, which comprises forming an ingot containing one or more of Ni and Co: 0.8 to 5.0% by mass, Si: 0.2 to 1.5% by mass, and the balance being composed of copper and unavoidable impurities. The ingot is hot rolled from 800 to 1000 ° C to adjust the thickness to 5 to 20 mm, and the conductivity is adjusted to 30% IACS or more, followed by cold rolling and softening with a processing degree of 30 to 99.5%. Pre-annealing of 0.20~0.80, cold rolling of 3~50%, solid solution treatment of 5~300 seconds at 700~950°C, cold rolling of 0~60%, 350~600 The aging treatment of °C for 2~20 hours, the processing degree is 0~50% cold rolling; wherein the softness is set to S, the following formula indicates the softness: S=(σ ₀ -σ)/(σ ₀ -σ ₉₅₀ ) (here, σ ₀ is the tensile strength before pre-annealing, and σ and σ ₉₅₀ are tensile strengths after pre-annealing and annealing at 950 ° C, respectively). The method for producing a Carson alloy according to Item 9 of the patent application, wherein the ingot contains 0.005 to 3.0% by mass of total of Sn, Zn, Mg, Fe, Ti, Zr, Cr, Al, P, One or more of Mn, Co, Cr, and Ag. A copper-strength article comprising a Carson alloy having any one of claims 1 to 8. An electronic machine part comprising the Carson alloy of any one of claims 1 to 8.