JP2011190469A - Copper alloy material, and method for producing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a copper alloy material which allows to reduce the influence of mechanical strength caused by cooling velocity after solution treatment, and has high mechanical strength and excellent bending workability in combination, and a method for producing the same. <P>SOLUTION: The copper alloy material has a composition comprising 2.0 to 4.0 mass% Ni by the mass ratio (Ni/Si) of 3.0 to 4.5 to 0.5 to 1.5 mass% Si, and the balance Cu with inevitable impurities, ¾(the 0.2% proof stress of a quenched material)-(the 0.2% proof stress of an annealed material)¾≤50 MPa is satisfied, tensile strength is ≥800 MPa, 0.2% proof stress is ≥770 MPa, and the value (R/t) obtained by dividing the bending minimum radius R at which cracks are not generated in a W bending test by sheet thickness t is ≤1.0. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a copper alloy material and a manufacturing method thereof, and more particularly to a copper alloy material applied to electric / electronic component applications and a manufacturing method thereof.

  In recent years, various electric and electronic devices have been made thinner and lighter. Along with this, miniaturization of parts used in electrical and electronic equipment is also progressing.

  In order to reduce the size of this type of component, for example, electrical / electronic components such as terminals and connectors tend to require a narrow pitch between electrodes. Due to such downsizing, materials used for electric / electronic parts tend to be required to be thinner than before.

  On the other hand, even if the material used is thin, it is necessary to maintain the reliability of the electrical connection in the electric / electronic device, and therefore, a material having higher spring property than before is required. In order to ensure this high spring property, it is necessary to sufficiently increase the tensile strength and yield strength (hereinafter also referred to as “mechanical strength”) of the material.

  Further, along with such miniaturization, there is an increasing demand for manufacturing a component having a smaller and more complicated shape than the conventional one by integral molding. Therefore, there is a strong demand for a material having high bending workability that can be applied to bending work under severer conditions than before.

  Furthermore, at the same time as electrical / electronic devices are becoming smaller, thinner and lighter, performance is also increasing. Due to the increase in the number of electrodes and the increase in energization current accompanying the improvement in performance of this electric / electronic device, the generated Joule heat tends to increase, and the demand for a material having better conductivity than before is increasing.

  Conventionally, phosphor bronze and beryllium copper have been widely used as materials for electrical and electronic parts that require high spring properties. However, in the case of phosphor bronze, the electrical conductivity is limited to about 20% IACS, and thus there is a problem that it cannot cope with the increase in the Joule heat described above. On the other hand, in the case of beryllium copper, although it has both high spring properties and good electrical conductivity, it is expensive and has a limit to be widely applied to general-purpose parts.

  Therefore, a copper alloy material such as a Cu (copper) -Ni (nickel) -Si (silicon) system has been used as a low-cost material because of demands for high spring properties and good electrical conductivity (for example, patent documents). 1, Patent Document 2, Patent Document 3 and Patent Document 4).

The copper alloy material mainly composed of Cu—Ni—Si is a precipitation strengthening type alloy having Ni ₂ Si as a precipitation strengthening phase, and has a conductivity of around 40% IACS. Therefore, it is possible to cope with an increase in Joule heat. Further, this copper alloy material can be manufactured at a lower cost than beryllium copper, and can be provided at low cost as electrical / electronic parts such as terminals, connectors, and lead frames.

Japanese Patent No. 2572042 Japanese Patent No. 2977745 Japanese Patent Laid-Open No. 2008-1937 JP 2008-75152 A

  For demands of high spring properties and high mechanical strength, Sn (tin), Mg (magnesium), Fe (iron), Co (cobalt), Ti (titanium), Cr based on the Cu-Ni-Si system This has been addressed by adding elements such as (chromium). However, the mechanical strength is sensitively influenced by the cooling rate after the solution treatment. Specifically, when the cooling rate is slow, the mechanical strength of the Cu—Ni—Si based copper alloy material is greatly reduced. there were. For this reason, the yield in mass production has not improved.

  Accordingly, the present invention has been made to solve the above-described conventional problems, and a specific object thereof is to reduce the influence of mechanical strength due to the cooling rate after solution treatment. Another object of the present invention is to provide a copper alloy material having both high mechanical strength and excellent bending workability, and a method for producing the same.

  In order to solve the above-described conventional problems, the present inventors have conducted extensive studies on the influence of the cooling rate after solution treatment on the mechanical strength. As a result, the quenching susceptibility of the copper alloy becomes a characteristic of the copper alloy material. The knowledge that it contributes greatly was acquired. That is, when the quenching sensitivity is high, it becomes a cause that the characteristics of the Cu—Ni—Si based copper alloy material cannot be sufficiently exhibited in the mass production process in which the cooling rate tends to be slower than that of the small scale trial manufacture. Since the volume of the mass-produced Cu—Ni—Si based copper alloy material is relatively large, the cooling rate differs between the surface side and the core side, and the mechanical properties of the manufactured Cu—Ni—Si based copper alloy material The strength cannot be maintained, and the variation tends to occur. On the contrary, when quenching sensitivity is low, not only the average value of mechanical strength is high, but also its variation is less likely to occur.

In order to suppress this quenching sensitivity to a low level, it was found that the following conditions (i) to (d) should be satisfied. In other words, if the following conditions are satisfied, the influence of the mechanical strength due to the cooling rate after the solution treatment before commercialization can be kept low, and the high mechanical strength and excellent bending workability, etc. As a result, it has been found that practical problems do not occur as electronic / electrical parts as final products, and the present invention has been achieved.
(B) Absolute value of the value obtained by subtracting the 0.2% proof stress of the quenched material rapidly cooled (water cooled) after solution treatment and before cold rolling, and the 0.2% proof stress of the gradually cooled (air cooled) material. Stipulated below a certain value,
(B) Specifying each of the tensile strength of the slow cooling material and the 0.2% yield strength of the slow cooling material within a certain range,
(C) The value (R / t) obtained by dividing the minimum bending radius R, which does not cause cracks in the W-bending test of the slow-cooled material, by the sheet thickness t (R / t) is specified in a certain range.
(D) By the above (a) to (c), the basic composition content of the copper alloy material and the sub-composition content of the copper alloy material are defined within a certain range.

[1] That is, in order to achieve the above object, the present invention provides 2.0 to 4.0% by mass of Ni to 3.0 to 4.5% by mass of Si to 0.5 to 1.5% by mass of Si. A slow cooling material that is contained in a mass ratio (Ni / Si), the balance is made of Cu and inevitable impurities, and is slowly cooled after solution treatment, satisfies the following requirements (1) to (4): It is in copper alloy material.
(1) | (0.2% yield strength of quenched material after solution treatment) − (0.2% yield strength of annealed material after solution treatment) | ≦ 50 MPa
(2) The annealed material has a tensile strength of 800 MPa or more,
(3) The 0.2% proof stress of the slow cooling material is 770 MPa or more,
(4) The value (R / t) obtained by dividing the minimum bending radius R at which no crack is generated in the W-bending test of the gradually cooled material by the thickness t is 1.0 or less.

[2] The copper alloy material according to the above [1] further contains at least one of 0.01 to 0.05% by mass of Sn and 0.02 to 0.1% by mass of Mg. It is said.

[3] The copper alloy material according to [1] or [2] is further 0.01 to 0.7 mass% Mn, 0.01 to 0.5 mass% Ag, 0.1 to 2.0. It is characterized by containing one or more kinds of Zn of mass%.

[4] In order to achieve the above object, the present invention further provides 2.0 to 4.0% by mass of Ni to 3.0 to 4.5% by mass of Si to 0.5 to 1.5% by mass of Si. (Ni / Si), 0.01 to 0.05% by mass of Sn, 0.02 to 0.1% by mass of Mg, and the balance being Cu, and inevitable The minimum bending radius R, which is composed of mechanical impurities and is slowly cooled after solution treatment, has a tensile strength of 800 MPa or more, 0.2% proof stress of the slow cooling material is 770 MPa or more, and does not generate cracks in the W bending test of the slow cooling material. In producing a copper alloy material having a value (R / t) divided by the thickness t of 1.0 or less, the 0.2% proof stress of the slow-cooled material and the 0.2% proof stress of the quenched material rapidly cooled after solution treatment Satisfies the following formula 1 in a method for producing a copper alloy material.
｜ (0.2% yield strength of quenched material) − (0.2% yield strength of annealed material) | ≦ 50 MPa …… Formula 1

[5] According to the method for producing a copper alloy material according to [4] above, the quenching material is rapidly cooled at a cooling rate of 100 ° C./second or more after the solution treatment of the copper alloy, , And cooling at a cooling rate of 10 ° C./sec or less.

[6] According to the method for producing a copper alloy material according to [4] above, 0.01 to 0.7% by mass of Mn, 0.01 to 0.5% by mass of Ag, 0.0. It is characterized by comprising adding at least one of 1 to 2.0% by mass of Zn.

[7] In order to achieve the above object, the present invention further provides 2.0 to 4.0% by mass of Ni to 3.0 to 4.5% by mass of Si to 0.5 to 1.5% by mass of Si. (Ni / Si), 0.01 to 0.05% by mass of Sn, 0.02 to 0.1% by mass of Mg, and the balance being Cu and unavoidable A step of preparing a copper alloy composed of mechanical impurities, a step of rolling the copper alloy, a step of solution treatment of the copper alloy after rolling in a temperature range of 750 to 950 ° C., and a solution treatment A step of cooling the copper alloy after cooling to 300 ° C. or less at a cooling rate of 10 ° C./second or more, a step of performing cold rolling on the copper alloy after cooling at a processing rate of 30% or less, The copper alloy after hot rolling has a step of performing an aging treatment for 1 to 50 hours in a temperature range of 370 to 500 ° C. To provide a method of manufacturing a copper alloy material to symptoms.

[8] In order to achieve the above object, the present invention further comprises 2.0 to 4.0% by mass of Ni, 0.5 to 1.5% by mass of Si, and a mass ratio (Ni / Si) of 3 In a Cu-Ni-Si alloy containing 0.0 to 4.5, with the balance being Cu and inevitable impurities, 0.01 to 0.05 mass% Sn, 0.02 to 0.1 mass 1% or more of Mg is added, and the annealed material that is annealed at a cooling rate of 10 ° C / second or less after the solution treatment satisfies the following requirements (1) to (3). A copper alloy material is provided.
(1) Tensile strength of the slow cooling material is 800 MPa or more,
(2) 0.2% proof stress of the slow cooling material is 770 MPa or more,
(3) The value (R / t) obtained by dividing the minimum bending radius R at which no crack is generated in the W-bending test of the gradually cooled material by the plate thickness t is 1.0 or less.

[9] In order to achieve the above object, the present invention further provides 2.0 to 4.0% by mass of Ni to 3.0 to 4.5% by mass of Si to 0.5 to 1.5% by mass of Si. (Ni / Si), 0.01 to 0.05% by mass of Sn, 0.02 to 0.1% by mass of Mg, and tensile strength of 800 MPa or more The 0.2% proof stress is 770 MPa or more, and the value (R / t) obtained by dividing the minimum bending radius R, which does not cause cracks in the W bending test, by the plate thickness t (R / t) is 1.0 or less. A copper alloy material is provided.

[10] In the copper alloy material according to [9], the copper alloy material further includes 0.01 to 0.7 mass% Mn, 0.01 to 0.5 mass% Ag, 0.1 to 0.1 mass%. It is characterized by containing any one or more of 2.0% by mass of Zn.

  According to the present invention, the mechanical strength due to the difference in cooling rate between the surface portion and the core portion of the copper alloy material, which is likely to occur in the mass production process, is reduced by reducing the influence of the mechanical strength due to the cooling rate after the solution treatment. It becomes possible to stabilize by reducing the variation in strength, and further to have mechanical strength and bending workability superior to those of conventional copper alloy materials.

It is the flowchart which showed the process of manufacturing the copper alloy material which concerns on suitable embodiment of this invention.

  Hereinafter, preferred embodiments of the present invention will be specifically described.

(Composition of copper alloy material)
The composition of the copper alloy material in this embodiment is as follows. The mass ratio of Ni is 2.0 to 4.0 mass% with respect to 0.5 mass% to 1.5 mass% Si (Ni / Si), 0.01 to 0.05% by mass of Sn, 0.02 to 0.1% by mass of Mg and at least one of Mg and inevitable impurities. . Preferably, any one of 0.01 to 0.7% by mass of Mn (manganese), 0.01 to 0.5% by mass of Ag (silver), 0.1 to 2.0% by mass of Zn (zinc) It is preferable to further contain one or more kinds. This Cu—Ni—Si based copper alloy material can be effectively used as a material used for electric / electronic parts such as terminals, connectors, switches, relays, and lead frames.

  The reasons for adding and limiting the alloy components of the copper alloy material according to the embodiment configured as described above will be described below.

(Ni and Si)
Ni and Si are elements added to precipitate and disperse intermetallic compounds containing these as main components in the material. This intermetallic compound increases the mechanical strength and springiness of the material, and can maintain good electrical conductivity. When the contents of Ni and Si are small, the intermetallic compound cannot be sufficiently dispersed, and high mechanical strength cannot be obtained. On the other hand, when there is too much content of Ni and Si, castability will fall and manufacture will become difficult.

  In this embodiment, the Ni content is 2.0 to 4.0 mass%, the Si content is 0.5 to 1.5 mass%, and the mass ratio Ni / Si is 3.0. To 4.5, more preferably, the Ni content is specified to be 2.0 to 3.5% by mass, the Si content is specified to be 0.5 to 0.9% by mass, and the mass ratio is It is preferable to define Ni / Si to 4.0 to 4.5. Thereby, it is possible to effectively achieve both high mechanical strength and excellent bending workability.

(Sn and Mg)
Sn and Mg are elements added for strengthening the solid solution of the Cu matrix. If the amount of Sn and Mg added is small, sufficient mechanical properties and spring properties cannot be obtained. If the added amount of Sn and Mg is too large, Sn and Mg form an intermetallic compound with the main component of the Cu-Ni-Si-based copper alloy, and act as Ni and Si precipitation nuclei, resulting in high quenching sensitivity, Cause sensitization.

  In this embodiment, Sn is 0.01 to 0.05% by mass and Mg is 0.02 to 0.1% by mass. More preferably, Sn is 0.01 to 0.03%. It is preferable to prescribe | regulate to mass% and to prescribe Mg to 0.02-0.08 mass%. Thereby, high intensity | strength and low quenching sensitivity are realizable.

(Mn)
Mn is an element added to improve bending workability. An excessive amount of Mn is not preferable because it causes a decrease in electrical conductivity. Furthermore, when there is too much addition amount of Mn, it becomes a cause which raises quenching sensitivity.

  In this embodiment, Mn is set to 0.01 to 0.7% by mass, but it is more preferable to define Mn to 0.01 to 0.1% by mass. Thereby, favorable bending workability is realizable with high mechanical strength and high electrical conductivity.

(Ag)
Ag is an element added to increase heat resistance and to obtain high mechanical strength even at low Ni and Si concentrations. When the amount of Ag added is too large, it is not preferable because it causes sensitization of quenching sensitivity.

  According to this embodiment, Ag is set to 0.01 to 1.0% by mass, but it is preferable to define Ag to 0.01 to 0.5% by mass. More preferably, it is desirable to define Ag to 0.1 to 0.5% by mass. Thereby, high heat resistance and high mechanical strength are realizable.

(Zn)
Zn is an element added to improve secondary characteristics required for the material for terminals and connectors, such as plating adhesion, solder wettability, and migration resistance. If the amount of Zn added is too large, it is not preferable because it causes a decrease in electrical conductivity and sensitization of quenching sensitivity.

  In this embodiment, Zn is 0.1 to 2.0% by mass, but it is more preferable that Zn is 0.5 to 0.15% by mass. Thereby, secondary characteristics, such as plating adhesiveness, can be made favorable with favorable electrical conductivity and low quenching sensitivity.

(Evaluation of mechanical properties)
As for the copper alloy material having the above composition, it is important to evaluate the respective mechanical properties (quenching sensitivity) of the rapidly cooled (water-cooled) quenched material and the gradually cooled (air-cooled) slowly cooled material after the solution treatment. Further, the mechanical characteristics may be evaluated based on a variation (standard deviation) of 0.2% proof stress in the same material or a difference between the maximum value and the minimum value of 0.2% proof stress.

  In this embodiment, the quenching sensitivity is determined by measuring the tensile strength, 0.2% proof stress and elongation of the quenched material and slow-cooled material, the evaluation result of the W-bending test of the quenched material and the slowly-cooled material, and 0.2 of the quenched material. The difference between the% proof stress and the 0.2% proof stress of the slow-cooled material is calculated and judged from the evaluation result of the variation in mechanical characteristics. It is desirable that the quenching sensitivity is low. When quenching sensitivity is low, the 0.2% proof stress, the absolute value of the difference between them, and the value of tensile strength increase. By evaluating the quenching sensitivity, the contents of Cu, Ni, and Sn, which are the basic composition of the copper alloy material, can be defined within a specific range, and Mg, Mn, and Ag that are the sub-composition of the copper alloy material , Zn and the like can be defined within a specific range.

(Evaluation of 0.2% yield strength of quenching material and 0.2% yield strength of slow cooling material)
By using a copper alloy material having the composition configured as described above, 0.2% proof stress of a rapidly cooled material rapidly cooled at a cooling rate of 100 ° C./second or more after solution treatment, and a solution treatment It is preferable that the relationship with the 0.2% proof stress of a slow-cooled material that is subsequently cooled at a cooling rate of 10 ° C./second or less satisfies the following formula 1.
| (0.2% yield strength of quenched material)-(0.2% yield strength of annealed material) |

  Here, in the above formula 1, the value of 50 MPa is obtained by subtracting the 0.2% proof stress of the quenching material and the 0.2% proof stress of the slow cooling material in the Cu—Ni—Si based copper alloy material of this embodiment. The absolute value of the value is less than half the absolute value of the value obtained by subtracting the 0.2% proof stress of the quenched material and the 0.2% proof stress of the slow-cooled material in the conventional Cu-Ni-Si based copper alloy material. is there. By reducing this value, it becomes possible to reduce variations in mechanical strength due to a difference in cooling rate between the surface portion and the core portion of the copper alloy material that is likely to occur in the mass production process. Furthermore, even in a large-scale mass production process in which the cooling rate tends to be relatively slow, the mechanical characteristics of a small-scale trial can be approached.

(Evaluation of tensile strength, 0.2% proof stress, and R / t of annealed material)
By performing processing and heat treatment under appropriate conditions using a copper alloy material having the above composition, the annealed material has a tensile strength of 800 MPa or more, and the annealed material has a 0.2% proof stress of 770 MPa or more. A material in which the value (R / t) obtained by dividing the minimum bending radius R by which the crack is not generated in the W bending test by the thickness t (R / t) is 0 or more and 1.0 or less can be obtained.

  Here, that the tensile strength is 800 MPa or more and the 0.2% proof stress is 770 MPa or more means that it has a strength comparable to low beryllium copper. These values are sufficient as strength to ensure high spring properties that do not cause practical problems as electronic / electrical parts.

  The W bending test is a test method for evaluating the bending workability of copper alloy strips defined in JIS H3110, JIS H3130, and the technical standard JCBA T307 of the Japan Copper and Brass Association. If there is a bending workability in which the value R / t obtained by dividing the minimum bending radius R at which the crack is observed on the surface of the bent portion by the thickness t is 0 or more and 1.0 or less, the copper alloy material is an electronic / electrical component. It is evaluated as a material with good bending workability that does not cause any practical problems. Desirably, the value of R / t is in the range of 0 to 0.5.

(Manufacturing method of copper alloy material)
The copper alloy material according to this embodiment is effectively manufactured by sequentially performing the processes as shown in FIG. For example, a copper alloy having the above composition is cast as a raw material according to a conventional method (step S1), followed by hot rolling (step S2), solution treatment (step S3), rapid cooling (step S4), or slow cooling. It has a cooling (quenching) process, a cold rolling process (step S6), and an aging process (step S7).

(Casting and hot rolling)
In the hot rolling process (step S2 in FIG. 1), the obtained ingot (step S1 in FIG. 1) is heated and hot-rolled according to a conventional method to produce a copper alloy having a desired thickness.

(Solution treatment)
In the solution treatment (step S3 in FIG. 1), it is necessary to heat at a sufficiently high temperature to dissolve the alloy elements, and to cool rapidly in order to prevent the metal compound from re-depositing during the cooling process. is there. Therefore, the temperature of the copper alloy manufactured in steps S1 and S2 in FIG. 1 is first raised to 750 to 950 ° C. Preferably, the temperature rising holding temperature is in the temperature range of 800 to 900 ° C. This is because, at low temperatures, the alloy elements are not sufficiently dissolved, and ultimately high mechanical strength cannot be obtained, and at high temperatures, the mechanical strength decreases due to coarsening of the crystal grains of the parent phase. is there. After raising the temperature to the maximum temperature, the temperature is maintained for about 0.5 to 2 minutes. Then, it cools to 300 degreeC with the speed | rate of 10 degreeC / second or more (step S5 of FIG. 1).

(Cold rolling)
In the cold rolling process (step S6 in FIG. 1) after the solution treatment, for example, the cold rolling is performed to a target final plate thickness. The purpose of this cold rolling is to introduce lattice defects into the copper alloy appropriately, and to use it as a dislocation strengthening and precipitate generation site, to disperse more precipitates, and by the action of the precipitates The purpose is to improve the mechanical strength.

  If the cold rolling processing rate is too high, there is a problem that the elongation of the finally obtained copper alloy material is greatly reduced. Since this decrease in elongation leads to cracking during bending, it is necessary to keep the processing rate of cold rolling low. In this embodiment, the processing rate is defined as 30% or less. Desirably, it is preferable to define it to 15% or less. Thereby, the fall of elongation can be suppressed.

(Aging treatment)
The aging treatment (step S7 in FIG. 1) is performed to precipitate fine intermetallic compounds that contribute to strengthening. It is preferable to heat at a low temperature for a long time, but at an extremely low temperature, it takes a lot of time to precipitate an intermetallic compound, so that it is not suitable for a large-scale mass production process.

  On the other hand, when the temperature is raised to promote precipitation, the size of the intermetallic compound that precipitates becomes coarse, and high mechanical strength cannot be obtained. In this embodiment, the temperature range of the aging treatment is regulated to 370 to 500 ° C. More preferably, it is desirable to perform the aging treatment in a temperature range of 400 to 470 ° C. for about 1 to 50 hours. Thereby, high mechanical strength and excellent bending workability can be obtained.

(Rapid cooling treatment and slow cooling treatment)
The purpose of the rapid cooling process (step S4 in FIG. 1) and the slow cooling process (step S5 in FIG. 1) is that the quenching sensitivity of the quenched material that has rapidly cooled the cooling rate after the solution treatment, and the after-solution treatment. The purpose is to evaluate the quenching sensitivity of the slow-cooled material with a slow cooling rate. In the evaluation, the quenching material and the slow cooling material after the solution treatment are first subjected to aging treatment, and then mechanical properties and bending workability are evaluated. Thereby, each condition of the solution treatment, quenching treatment, cold rolling, and aging treatment is set.

  In the rapid cooling treatment, the solutionized copper alloy is rapidly cooled at a cooling rate of 10 to 1000 ° C./second. In the slow cooling treatment, the copper alloy is slowly cooled at a cooling rate of 1 to 10 ° C./second. Using this processed and heat-treated quenched and annealed material, the ratio of the minimum bending radius R to the thickness t where cracks do not occur in the tensile strength, 0.2% proof stress, elongation, and W bending test of the quenched and annealed material / T and the quality evaluation is performed based on the quenching sensitivity based on the difference between the 0.2% proof stress of the quenched material and the 0.2% proof stress of the gradually cooled material (step S8 in FIG. 1).

  The quenching treatment of the quenching material and the slow cooling material is performed respectively, and the difference between the 0.2% proof stress of the quenching material and the 0.2% proof stress of the slow cooling material is | (0.2% proof stress of the quenching material) − (0. 2% yield strength) | ≦ 50 MPa, whether the tensile strength of the annealed material is 800 MPa or more, whether the 0.2% yield strength of the annealed material is 770 MPa or more, the W-bending test of the annealed material Whether or not the value (R / t) obtained by dividing the minimum bending radius R at which cracks do not occur by the plate thickness t (R / t) is 1.0 or less is determined. If these conditions are satisfied, even if the cooling rate is slowed down using a large-scale mass production facility, the difference in mechanical characteristics, bending workability, and variation is reduced, so that variations among manufacturing facilities are reduced.

(Effect of embodiment)
According to the above embodiment, the following various effects can be achieved.
(1) It is possible to suppress the mechanical strength to a small extent without being influenced by the mechanical strength resulting from the cooling rate after solution treatment. Mechanical properties can be obtained.
(2) A copper alloy material for electrical and electronic equipment parts having both a high tensile strength of 800 MPa or more, a high 0.2% proof stress of 770 MPa or more, and excellent bending workability due to the exceptional effect of (1) above. Can be effectively obtained.
(3) Due to the special effects of (1) and (2) above, it is possible to reduce variations in mechanical properties due to the difference in cooling rate between the surface portion and the core portion of the copper alloy material that is likely to occur in the mass production process. As a result, it is possible to effectively obtain a copper alloy material for electric / electronic device parts having stable mechanical characteristics.
(4) Due to the special effects of (1) and (2) above, electrical / electronic equipment parts using copper alloy materials can be easily reduced in size, and the design flexibility can be greatly expanded. .
(5) It can be manufactured at a manufacturing cost equivalent to that of a conventional copper alloy material without using a special manufacturing method or apparatus. Therefore, it becomes possible to improve the manufacturing technology for electrical / electronic device parts at low cost, and can greatly contribute to the development.

  The present invention naturally includes a technical range that can be easily changed by those skilled in the art from the above-described embodiments.

  Hereinafter, examples and comparative examples will be described in detail as more specific embodiments of the present invention. These examples give typical examples of the above-described embodiments, and the present invention is of course not limited to these examples and comparative examples.

  The copper alloy materials of Examples 1 to 12 and Comparative Examples 1 to 11 were produced under the conditions described in detail below, and the compositions of the obtained copper alloy materials were compared and evaluated. Table 1 shows the composition of each copper alloy material. In Table 1, inevitable impurities are included in Cu.

[Example 1]
In order to produce the copper alloy material of Example 1, first, 2.5% by mass of Ni, 0.6% by mass of Si, and 0.05% by mass of Mg are contained, and the balance is made up of Cu and inevitable impurities. The resulting copper alloy was melted in a high-frequency melting furnace (Ar atmosphere) using oxygen-free copper as a base material, and cast into an ingot having a diameter of 30 mm and a length of 250 mm. The obtained ingot was heated to 900 ° C. and extruded (hot processing) to produce a plate-like copper alloy having a width of 20 mm and a thickness of 8 mm.

  This plate-like copper alloy was cold-rolled to a thickness of about 0.25 mm (rolled without applying heat from the outside), and held in a salt bath at about 850 ° C. for about 1 minute for solution treatment. Thereafter, the copper alloy was water-cooled (cooling rate: 500 to 1000 ° C./second) or air-cooled (cooling rate: 1 to 10 ° C./second) to produce a rapid cooling material or a slow cooling material.

  Next, the rapid cooling material or the slow cooling material was cold-rolled (rolled without applying heat from the outside) to a thickness of about 0.2 mm. At this time, only the processing heat is applied to the material. Thereafter, an aging treatment was performed on the rapidly cooled material or the slowly cooled material at a temperature of about 450 ° C. for about 4 hours.

  About the copper alloy material of Example 1 manufactured as mentioned above, the tension test and W bending test of the quenching material and the slow cooling material were implemented. The tensile test was performed by a method based on JIS Z2241, and the tensile strength, 0.2% proof stress, and elongation were measured. On the other hand, the W bending test is performed by a method according to JIS H3110 and JIS H3130 using a test piece taken so that the bending axis is parallel to the rolling direction of the copper alloy material, and the surface of the test piece is cracked. Evaluation was based on the ratio R / t between the minimum bending radius R (mm) that did not occur and the thickness t (mm) of the test piece. And the 0.2% yield strength of the slow cooling material was subtracted from the 0.2% yield strength of the quenched material, and the quenching sensitivity was evaluated.

  As a result, the tensile strength of the annealed material was 803 MPa, the 0.2% yield strength of the annealed material was 779 MPa, and the elongation of the annealed material was 7.2 and R / t = 0. The difference between the 0.2% yield strength of the quenched material and the 0.2% yield strength of the slow-cooled material was 11 MPa. A copper alloy material having excellent quenching sensitivity, which is an initial object in this embodiment, and having high mechanical strength and good bending workability was obtained. Table 2 summarizes the measurement results of the tensile strength, 0.2% proof stress, and elongation of the quenched material and slow-cooled material, and the evaluation results of the W-bending test.

[Examples 2 to 12]
The copper alloy material of Examples 2-12 shown in Table 1 was manufactured using the manufacturing method and process similar to the said Example 1. FIG.

  The copper alloy materials of Examples 2 to 5 exemplify an example in which the addition amount of Ni and Si is changed within a mass ratio of Ni / Si of 4.0 to 4.5. On the other hand, the copper alloy material of Example 6 is an example in which the mass ratio of Ni / Si is changed to 3.08.

  The copper alloy materials of Examples 7 and 8 exemplify an example in which the additive amount ratio of Ni and Si is set to 4 and the Mg additive amount is changed to 0.03 as in Example 2 above.

  The copper alloy material of Example 9 illustrates an example in which 0.03% by mass of Sn is added instead of Mg.

  The copper alloy material of Example 10 is an example in which 0.2% by mass of Mn is further added to the same composition as in Example 2 above, and the copper alloy material of Example 11 is 0 in the same composition as in Example 1 above. This is an example in which 2% by mass of Ag is added. The copper alloy material of Example 12 illustrates an example in which 0.2% by mass of Zn is added to the same composition as in Example 2 above.

  Even in the copper alloy materials of Examples 2 to 12 manufactured as described above, as in Example 1, the tensile strength, 0.2% proof stress, and elongation of the quenching material and the slow cooling material were evaluated. The results of the W bending test were evaluated. In Table 2, the measurement results of the tensile strength, 0.2% proof stress, and elongation of the copper alloy materials of Examples 2 to 12 and the evaluation results of the W bending test are collectively shown.

  As is apparent from Table 2, all of the copper alloy materials of Examples 2 to 12 are excellent in quenching sensitivity, which is the initial purpose of the present invention, and have both high mechanical strength and good bending workability. The material was found to be obtained.

[Comparative example]
The copper alloy materials of Comparative Examples 1 to 11 shown in Table 1 were manufactured using the same manufacturing method and process as in Example 1 above. For these copper alloy materials, as in Example 1, the tensile strength, 0.2% proof stress, and elongation of the quenched and annealed materials were evaluated, and the results of the W bending test were evaluated. In Table 2, the measurement results of the tensile strength, 0.2% proof stress, and elongation of the copper alloy materials of Comparative Examples 1 to 11 and the evaluation results of the W bending test are collectively shown.

[Comparative Example 1]
The copper alloy material of Comparative Example 1 exemplifies an example in which Mg, which is a subsidiary component, is not added to the same basic composition component as in Example 2 above. As is clear from Table 2, in the copper alloy of Comparative Example 1, the difference in 0.2% proof stress between the quenched material and the slow-cooled material was within 50 MPa as compared with each of the above examples, and showed a good value. However, it was found that sufficient tensile strength and 0.2% proof stress cannot be obtained.

[Comparative Examples 2 and 3]
The copper alloys of Comparative Examples 2 and 3 exemplify an example in which the addition amount of the basic composition component Si and the Ni / Si mass ratio are outside the specified range. As is clear from Table 2, in the copper alloy materials of Comparative Examples 2 and 3, the difference in 0.2% proof stress between the quenched material and the slow-cooled material is within 50 MPa, which is a good value as compared with the above examples. However, it was found that sufficient tensile strength and 0.2% yield strength could not be obtained.

[Comparative Examples 4 and 5]
The copper alloys of Comparative Examples 4 and 5 are examples in which Mg, which is a subcomponent, is added to the same basic composition component as in Example 2 in an addition amount outside the specified range. As is clear from Table 2, when the amount of Mg added is small as in Comparative Example 4, the difference in 0.2% proof stress between (quenched material) and (gradually cooled material) as compared with each of the above examples, Although it was within 50 MPa and showed a good value, it was found that sufficient tensile strength and 0.2% yield strength could not be obtained. When the amount of Mg added is large as in Comparative Example 5, there is a large difference between the 0.2% proof stress of the quenching material and the 0.2% proof stress of the slow cooling material, and it is difficult to say that the quenching sensitivity is good.

[Comparative Example 6]
The copper alloy of Comparative Example 6 is an example in which Sn, which is a subcomponent, is added to the same basic composition component as in Example 2 in an addition amount not more than a specified range. As is apparent from Table 2, the difference in 0.2% yield strength between the quenched material and the slow-cooled material was within 50 MPa and showed good values, but the tensile strength and 0.2% yield strength showed good values. It's hard to say.

[Comparative Example 7]
The copper alloy material of Comparative Example 7 is an example in which Sn, which is a subcomponent, is added to the same basic composition component as in Example 2 in an addition amount of a specified range or more. As is clear from Table 2, it is difficult to say that the tensile strength, 0.2% proof stress, and the difference between the 0.2% proof stress of the quenched material and the slowly cooled material are good.

[Comparative Examples 8 to 11]
The copper alloy material of Comparative Example 8 exemplifies an example in which Mn, which is a subcomponent, is added to the same composition component as in Example 2 in an addition amount of a specified range or more. The copper alloy material of Comparative Example 9 is an example in which Ag, which is a subcomponent, is added to the same composition component as in Example 1 in an addition amount of a specified range or more. The copper alloy material of Comparative Example 10 is an example in which Ag, which is a subcomponent, is added to the same composition component as in Example 2 in an addition amount of a specified range or more. The copper alloy material of Comparative Example 11 is an example that was prototyped with reference to Patent Document 3 described above. As is apparent from Table 2, all of the copper alloy materials of Comparative Examples 8 to 11 have high quenching sensitivity, and the 0.2% proof stress of the slow-cooled material is greatly reduced compared to the 0.2% proof stress of the quenched material. I found out that

(About reduction of quenching sensitivity and variation of 0.2% proof stress)
Hereinafter, quenching sensitivity and 0.2% proof stress will be specifically described based on Tables 2 and 3. Tables 2 and 3 list typical examples of the 0.2% proof stress in the above examples and comparative examples, and the present invention is not limited to these examples and comparative examples.

  First, as can be seen from Tables 1 and 2, it can be seen that the quenching sensitivity evaluated by the difference in 0.2% proof stress between the quenched material and the slowly cooled material can be controlled by Sn, Mg, Mn, Zn and Ag. That is, Sn is 0.05% by mass, Mg is 0.03% by mass, Mn is 0.7% by mass, Ag is 0.5% by mass, and Zn exceeds any upper limit of 2.0% by mass. And quenching sensitivity becomes high.

  Table 3 shows that the variation in 0.2% yield strength of the same copper alloy material after aging treatment differs depending on the difference in quenching sensitivity, that is, the difference in 0.2% yield strength between the quenched material and the slow-cooled material. . Details will be described below.

  In Example 7 and Comparative Example 5 illustrated in Table 3, as shown in Table 1, Ni, Si, and Mg, which are the same composition components, are added to Cu, but in the copper alloy material of Comparative Example 5, , Mg addition amount exceeds the specified range.

  Ten specimens (N = 10) of these copper alloy materials are sampled in the longitudinal direction to prepare tensile test pieces, and 0.2% proof stress at each longitudinal position is obtained according to the conditions in accordance with the tensile test specified in JIS Z2241. Measurements were made. And the average value of 0.2% yield strength and the standard deviation of 0.2% yield strength were calculated | required. The results are summarized in Table 3.

  As is clear from Table 3, the average value of the 0.2% proof stress of the copper alloy in Comparative Example 5 is approximately the same as that of the copper alloy material of Example 7.

  However, the copper alloy material of Example 7 has low quenching sensitivity and small 0.2% proof stress variation (standard deviation).

  On the other hand, in the copper alloy material of Comparative Example 5, the 0.2% yield strength variation (standard deviation) is large as compared with the copper alloy material of Example 7 having high quenching sensitivity and low quenching sensitivity.

  From the above, by controlling the addition amount of Mg, Sn, Ag, Zn, and Mn as in the above Examples 1 to 12, quenching sensitivity is suppressed to a low level, and variation in 0.2% yield strength within the same material is reduced. I was able to confirm that I can do it.

Claims (10)

2.0 to 4.0 mass% Ni is contained in a ratio of 3.0 to 4.5 mass (Ni / Si) with respect to 0.5 to 1.5 mass% Si, the balance being Cu, A copper alloy material, characterized in that a slow cooling material comprising inevitable impurities and gradually cooled after solution treatment satisfies the following requirements (1) to (4).
(1) | (0.2% yield strength of quenched material after solution treatment) − (0.2% yield strength of annealed material after solution treatment) | ≦ 50 MPa
(2) The annealed material has a tensile strength of 800 MPa or more,
(3) The 0.2% proof stress of the slow cooling material is 770 MPa or more,
(4) The value (R / t) obtained by dividing the minimum bending radius R at which no crack is generated in the W-bending test of the gradually cooled material by the thickness t is 1.0 or less.   2. The copper alloy material according to claim 1, further comprising at least one of 0.01 to 0.05 mass% of Sn and 0.02 to 0.1 mass% of Mg. Copper alloy material.   The copper alloy material further contains at least one of 0.01 to 0.7% by mass of Mn, 0.01 to 0.5% by mass of Ag, and 0.1 to 2.0% by mass of Zn. The copper alloy material according to claim 1 or 2, characterized in that: 2.0 to 4.0 mass% Ni is contained at a mass ratio (Ni / Si) of 3.0 to 4.5 with respect to 0.5 to 1.5 mass% Si, and 0.01 to Tensile strength of slow-cooled material containing 0.05% by mass of Sn or 0.02 to 0.1% by mass of Mg, the balance being Cu and unavoidable impurities, and gradually cooled after solution treatment The value (R / t) obtained by dividing the minimum bending radius R by which the strength is 800 MPa or more, the 0.2% proof stress of the slow cooling material is 770 MPa or more, and no crack is generated in the W bending test of the slow cooling material by the thickness t (1.0). In producing the following copper alloy material,
A method for producing a copper alloy material, wherein the 0.2% proof stress of the slow-cooled material and the 0.2% proof strength of the quenched material quenched after the solution treatment satisfy the following formula 1.
｜ (0.2% yield strength of quenched material) − (0.2% yield strength of annealed material) | ≦ 50 MPa …… Formula 1   The quenching material is rapidly cooled after the solution treatment of the copper alloy at a cooling rate of 100 ° C / sec or more, and the slow cooling material is slowly cooled at a cooling rate of 10 ° C / sec or less. The method for producing a copper alloy material according to claim 4.   Adding at least one of 0.01 to 0.7% by mass of Mn, 0.01 to 0.5% by mass of Ag, and 0.1 to 2.0% by mass of Zn to the copper alloy. The manufacturing method of the copper alloy material of Claim 4 characterized by the above-mentioned. 2.0 to 4.0% by mass of Ni is added at a mass ratio (Ni / Si) of 3.0 to 4.5 with respect to 0.5 to 1.5% by mass of Si, and 0.01 to Adding one or more of 0.05% by mass of Sn and 0.02 to 0.1% by mass of Mg, and preparing a copper alloy consisting of Cu and inevitable impurities in the balance;
Rolling the copper alloy;
A step of subjecting the copper alloy after the rolling process to a solution treatment in a temperature range of 750 to 950 ° C .;
Cooling the copper alloy after the solution treatment to 300 ° C. or lower at a cooling rate of 10 ° C./second or more;
A step of cold rolling the copper alloy after cooling at a processing rate of 30% or less;
The manufacturing method of the copper alloy material characterized by having the process of performing the aging treatment for 1 to 50 hours in the temperature range of 370-500 degreeC for the said copper alloy after cold rolling. It contains 2.0 to 4.0 mass% Ni, 0.5 to 1.5 mass% Si in a mass ratio (Ni / Si) in the range of 3.0 to 4.5, with the balance being Cu. In addition, one or more of 0.01 to 0.05% by mass of Sn and 0.02 to 0.1% by mass of Mg are added to a Cu—Ni—Si alloy composed of inevitable impurities to form a solution. A copper alloy material, characterized in that a slow-cooled material that is gradually cooled at a cooling rate of 10 ° C / second or less after the processing satisfies the following requirements (1) to (3).
(1) Tensile strength of the slow cooling material is 800 MPa or more,
(2) 0.2% proof stress of the slow cooling material is 770 MPa or more,
(3) The value (R / t) obtained by dividing the minimum bending radius R at which no crack is generated in the W-bending test of the gradually cooled material by the plate thickness t is 1.0 or less.   2.0 to 4.0 mass% Ni is contained at a mass ratio (Ni / Si) of 3.0 to 4.5 with respect to 0.5 to 1.5 mass% Si, and 0.01 to It contains any one or more of 0.05% by mass of Sn and 0.02 to 0.1% by mass of Mg, has a tensile strength of 800 MPa or more, 0.2% proof stress of 770 MPa or more, W A copper alloy material characterized in that a value (R / t) obtained by dividing a minimum bending radius R at which bending does not occur in a bending test by a sheet thickness t (R / t) is 1.0 or less.   The copper alloy material further contains at least one of 0.01 to 0.7% by mass of Mn, 0.01 to 0.5% by mass of Ag, and 0.1 to 2.0% by mass of Zn. The copper alloy material according to claim 9.

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