JP6133178B2 - Copper alloy sheet and manufacturing method thereof - Google Patents

Description

  The present invention is a copper alloy suitable for lead frames, relays, switches, sockets, etc., as well as connectors for in-vehicle components and peripheral infrastructure, solar power generation systems, etc., centering on EVs (Electronic Vehicles) and HEVs (Hybrid Electric Vehicles). It is related with a board | plate material and its manufacturing method.

Copper alloys are generally used in applications such as in-vehicle components such as EVs and HEVs, connectors for peripheral infrastructure, solar power generation systems, and other lead frames, relays, switches, sockets, and the like. In recent years, high current density of circuits has progressed due to high voltage of circuit power supply and miniaturization of electronic equipment, and there is concern about resistance heat generation during energization and concomitant deterioration of circuit connection reliability. A material with a high rate is required.
In addition, when a connector is repeatedly inserted and removed or a switch is switched, or when vibration is applied to a component, circuit disconnection due to fatigue failure of the material also becomes a problem. Fatigue properties are also required.
In addition to the increase in resistance heat generation during energization, the use environment is also increasing in temperature. From the viewpoint of circuit connection reliability, a material that also has stress relaxation resistance is preferable.
However, in general, in order to improve the fatigue resistance and stress relaxation resistance of a material, it is necessary to add an alloy component to the copper alloy material, and as a result, the electrical conductivity decreases. Was difficult.

  Cu—Cr-based copper alloys are known to have moderate strength and high conductivity. In Document 1, fatigue resistance is improved by controlling the number of specific inclusions in a Cu—Cr—Zr copper alloy. In Document 2, the stress relaxation resistance is improved by adding Zr, Sn, and Mg and controlling the size and number of precipitates. However, these only focus on improving each of fatigue resistance and stress relaxation characteristics, and no copper alloy sheet material that has been improved at the same time has been found so far.

Japanese Patent No. 4130593 JP 2012-12644 A

  In applications such as EV, HEV and other in-vehicle components, connectors for peripheral infrastructure, solar power generation systems, and other lead frames, relays, switches, sockets, etc., conductivity and fatigue resistance, in addition to this, In spite of the demand for copper alloy sheets having stress relaxation properties, there has been no invention that improves these properties at the same time.

  In view of the above circumstances, the object of the present invention is to provide strength and conductivity suitable for in-vehicle components such as EVs and HEVs, peripheral infrastructure, connectors for solar power generation systems, other lead frames, relays, switches, sockets, and the like. Another object of the present invention is to provide a copper alloy sheet material having fatigue resistance or further having stress relaxation characteristics and a method for producing the same.

  The inventors of the present invention have studied copper alloy sheet materials suitable for electric / electronic component applications, and have Cr of 0.10 to 0.50 mass%, Mg of 0 to 0.20 mass%, and at least of Zr and Ti. One type contains 0 to 0.20 mass% in total, and at least one of Zn, Sn, Ag, Si, and Fe contains 0 to 0.40 mass% in total, and the balance consists of Cu and inevitable impurities In the homogenization heat treatment of the copper alloy sheet, it is possible to more efficiently dissolve the compound in the copper matrix by controlling the rate of temperature increase from room temperature to 500 ° C and from 500 ° C to the final temperature. I found it. Furthermore, the water cooling after hot working is performed at a cooling rate of 0.1 to 10 ° C./second up to 750 ° C., and the material after cold rolling is subjected to aging heat treatment under specific conditions, thereby increasing strength, conductivity, It has been found that a copper alloy sheet material having both fatigue characteristics and stress relaxation resistance characteristics can be obtained. The present invention has been made based on this finding.

The above object of the present invention is achieved by the following means.
(1) Cr is 0.10 to 0.50 mass%, Mg is 0 to 0.20 mass%, and at least one of Zr and Ti is 0 to 0.20 mass% in total, Zn, Sn, Ag, It is a copper alloy sheet containing at least one of Si and Fe in a total of 0 to 0.40 mass%, the balance being Cu and inevitable impurities, and particles observed when a parallel section in the processing direction is observed. There are 1 × 10 ¹ to 1 × 10 ³ particles / mm ^{2 in} which the aspect ratio a / b obtained by dividing the major axis a by the minor axis b is more than 2 and less than 5, and the minor axis b is 100 nm or more. A copper alloy sheet characterized by the above.
(2) The copper matrix phase contains 1 × 10 ⁹ to 1 × 10 ¹² particles / mm ^{2 of} an alloy component having a particle size of 5 to 50 nm or a compound containing an alloy component. Item 4. The copper alloy sheet according to Item 1.
(3) The copper alloy sheet according to (1) or (2), wherein Mg is contained in the copper matrix phase in an amount of 0.01 to 0.20 mass%.
(4) The copper according to any one of (1) to (3), wherein the copper matrix contains at least one of Zr and Ti in a total amount of 0.01 to 0.20 mass%. Alloy plate material.
(5) In any one of (1) to (4), the copper matrix phase contains at least one of Zn, Sn, Ag, Si, and Fe in a total amount of 0.01 to 0.40 mass%. The copper alloy sheet material according to claim 1.
(6) A method for producing a copper alloy sheet according to any one of (1) to (5), wherein (a) homogenization heat treatment is performed at room temperature on an ingot obtained by melting and casting a copper alloy component. From 500 ° C. to 500 ° C./min or less, then at a rate of 2 ° C./min or more, the temperature is raised to 900 to 1050 ° C. and reached for 0.5 to 12 hours (b) Processing is performed in a temperature range of 850 to 1000 ° C. (c) After hot working, it is cooled to 750 ° C. at a cooling rate of 0.1 to 10 ° C./second, then cooled with water, and face-cut, (d) 70 to 70 After cold working at a processing rate of 90% (e) aging heat treatment is performed at 400 to 500 ° C. for 10 minutes to 24 hours, and (f) the total processing rate of the material after the chamfering is 70 to 90% The manufacturing method of a copper alloy sheet | seat material which performs a finishing process so that it may become 0-50%.

  The copper alloy sheet material of the present invention is excellent in strength, conductivity, fatigue resistance and stress relaxation characteristics, and is equipped with EV, HEV and other in-vehicle components, peripheral infrastructure, connectors for solar power generation systems, other lead frames, relays, etc. Suitable for switches, sockets and the like.

  A preferred embodiment of the copper alloy sheet material of the present invention will be described in detail. Here, the “copper alloy plate” means a copper alloy material (before processing and having a predetermined alloy composition) processed into a predetermined shape (for example, a plate, a strip, a foil, etc.). Below, although a board | plate material and a strip are demonstrated as embodiment, the shape is not limited to this.

The copper alloy sheet of the present invention has an aspect ratio (a / b) of 2 <a / b <5 when the major axis a of the particle diameter is divided by the minor axis b when observing a parallel section in the processing direction. 1 × 10 ¹ to 1 × 10 ³ particles / mm ^{2 of} particles A having a minor axis b of 100 nm or more exist. In some cases, particles B having a particle diameter of 5 to 50 nm are contained in an amount of 1 × 10 ⁹ to 1 × 10 ¹² particles / mm ² .
The configuration of the copper alloy sheet of the present invention will be described in detail below.

<Particle A>
The particle A is a particle having an aspect ratio a / b obtained by dividing the major axis a of the particle diameter by the minor axis b and more than 2 and less than 5 (2 <a / b <5), and the minor axis b is 100 nm or more. In the copper alloy sheet of the present invention, the particle A contained in the copper alloy matrix is 1 × 10 ¹ to 1 × 10 ³ particles / mm ² , preferably 1 × 10 ¹ to 1 × 10 ² particles / mm ² . Thus, the parallel direction (RD) without impairing the fatigue resistance when the beam having the longitudinal direction (Transverse Direction; TD) as the longitudinal direction is vibrated with respect to the rolling direction (RD) of the copper alloy sheet material. It is possible to improve the fatigue resistance when a beam having a longitudinal length of) is vibrated. When the amount of particles A contained in the copper matrix is less than 1 × 10 ¹ particles / mm ² , improvement in fatigue resistance cannot be expected. On the other hand, when the number is more than 1 × 10 ³ pieces / mm ^{2, the} fatigue resistance when a beam having a longitudinal direction as a longitudinal direction with respect to the rolling direction is vibrated decreases. For particles having an aspect ratio of 2 or less, or particles having a minor axis of less than 100 nm, improvement in fatigue resistance cannot be expected. Further, particles having an aspect ratio of 5 or more tend to lower fatigue resistance when a beam having a longitudinal direction as a longitudinal direction with respect to the rolling direction is vibrated. The particles A are obtained by stretching coarse precipitates formed in the copper matrix phase in the hot working process from the homogenizing heat treatment process described later in the cold working process and the finishing process, which are the lower processes.

  In addition, the component of the particle | grains A in the copper alloy board | plate material of this invention consists of the alloy element mainly contained in a copper alloy board | plate material. That is, it contains an intermetallic compound having Cr, Mg, Zr, Ti, Zn, Sn, Ag, Si, Fe, and the like as essential elements or optional elements. The particles A are usually precipitates, but may be crystallized substances as long as the requirements defined in the present invention are satisfied.

<Particle B>
The particle B is a particle having a particle diameter of 5 nm or more and 50 nm or less. In the copper alloy sheet of the present invention, the particle B contained in the copper alloy matrix is 1 × 10 ⁹ to 1 × 10 ¹² particles / mm ² , preferably 1 × 10 ¹⁰ to 1 × 10 ¹² particles / mm ² . As a result, the strength and fatigue resistance of the copper alloy can be improved. When the amount of particles B contained in the copper matrix is less than 1 × 10 ⁹ particles / mm ² , improvement in strength and stress relaxation resistance cannot be expected. On the other hand, when it is more than 1 × 10 ¹² pieces / mm ² , the fatigue resistance of the material is lowered. With particles smaller than 5 nm, improvement in strength and stress relaxation resistance cannot be expected. Moreover, although the particle | grains B are obtained by making it precipitate in a copper parent phase in the aging heat treatment process mentioned later, in the manufacturing range of this invention, a thing larger than 50 nm is hardly formed.

  In addition, the component of the particle | grains B in the copper alloy board | plate material of this invention consists of the alloy element mainly contained in a copper alloy board | plate material. That is, it contains an intermetallic compound having Cr, Mg, Zr, Ti, Zn, Sn, Ag, Si, Fe, and the like as essential elements or optional elements. In addition, although the particle | grains B are precipitation normally, if the requirements prescribed | regulated by this application are satisfy | filled, a crystallization thing etc. may be sufficient.

<Cr>
By precipitating Cr in the copper alloy matrix, Cr can improve strength, fatigue resistance, and stress relaxation characteristics without impairing electrical conductivity. In the present invention, Cr is contained in an amount of 0.10 to 0.50 mass%, preferably 0.15 to 0.40 mass%. When the amount of Cr is less than 0.10 mass%, the amount of Cr or a compound containing Cr in the copper matrix decreases, so that desired strength, fatigue resistance, and stress relaxation characteristics cannot be obtained. On the other hand, if it exceeds 0.50 mass%, problems such as a decrease in conductivity, a decrease in strength and fatigue resistance due to the generation of coarse compounds in the copper matrix, and an adverse effect on workability arise.

<Mg>
Mg can be improved in strength, fatigue resistance, and stress relaxation characteristics by being present as a solid solution element in the copper matrix. In the present invention, Mg may be contained in an amount of 0 to 0.20 mass%, preferably 0.05 to 0.15 mass%. When the content is less than 0.05 mass%, the effect of improving the characteristics cannot be sufficiently obtained. When the content is more than 0.20 mass%, problems such as a decrease in conductivity and an adverse effect on workability occur.

<Ti, Zr>
By precipitating Ti and Zr in the copper matrix, the strength, fatigue resistance, and stress relaxation characteristics can be improved. In the present invention, at least one of Ti and Zr may be contained in a total of 0 to 0.20 mass%, preferably 0.05 to 0.15 mass%. When the content is less than 0.05 mass%, the effect of improving the characteristics cannot be sufficiently obtained. When the content is more than 0.20 mass%, problems such as a decrease in conductivity and an adverse effect on workability occur.

<Zn, Fe, Sn, Ag, Si>
By adding Zn, Fe, Sn, Ag, and Si, material properties such as strength, fatigue resistance, stress relaxation resistance, pressability, and plating properties can be improved. In the present invention, at least one of Zn, Fe, Sn, Ag, and Si may be contained in a total amount of 0 to 0.40 mass%, preferably 0.01 to 0.30 mass%. If the content is less than 0.01 mass%, the above-mentioned property improvement effect cannot be obtained sufficiently. If the content is more than 0.40 mass%, problems such as decreased conductivity, adverse effects on workability, and increased raw material costs arise. .

Next, the manufacturing method of the copper alloy sheet | seat material of this invention is demonstrated.
The copper alloy sheet of the present invention is usually subjected to homogenization heat treatment → hot working → face milling → cold working → aging heat treatment to the ingot obtained by melt casting, and then finish processing as necessary. Manufactured by performing strain relief annealing as necessary.

<Homogenization heat treatment>
The homogenization heat treatment is performed in order to solidify the compound contained in the ingot in the copper matrix and to homogenize the ingot components. If most of the compound remains in the ingot in this step, the amount of particles A and B cannot be controlled in the steps after hot working described later, and desired properties cannot be obtained in the final product. The coarser the compound contained in the ingot, the more difficult it is to dissolve in the copper matrix. Conventionally, during the temperature increase of the homogenization heat treatment, the solid solution element contained in the copper alloy matrix until the compound contained in the ingot reaches a temperature near the final temperature at which the solid solution starts in the copper matrix. Precipitating with the compound that originally existed as a nucleus coarsened the compound, increasing the difficulty of solid solution.

  On the other hand, in the present invention, by controlling the rate of temperature increase from room temperature (about 25 ° C.) to 500 ° C. and from 500 ° C. to the final temperature, the compound is dissolved more efficiently in the copper matrix. I found out that That is, in the present invention, by setting the rate of temperature increase from room temperature to 500 ° C. to 5 ° C./min or less, fine compounds are once precipitated and grown in the copper matrix during the temperature increase to 500 ° C. Reduce the amount of dissolved elements in the matrix. Thereafter, by raising the temperature to the final temperature at a rate of 2 ° C./min or more, the temperature can be raised to the vicinity of the final temperature while suppressing the growth of the compound originally present in the copper matrix phase. For this reason, compared with the conventional homogenization heat treatment, the compound is easily dissolved in the copper matrix phase, and the number of compounds remaining in the copper matrix phase after the heat treatment is reduced. As a result, the number of the compound B in the final product is also reduced. Decrease. When the rate of temperature increase from room temperature to 500 ° C. is greater than 5 ° C./min, fine precipitates that precipitate in the copper matrix do not grow sufficiently during temperature increase, and the solid solution elements in the copper matrix decrease. Since the amount is small, the growth of the originally existing compound is not suppressed in the subsequent temperature increase to the final temperature. Even if the rate of temperature increase from room temperature to 500 ° C is 5 ° C / min or less, if the rate of temperature increase from 500 ° C to the final temperature is less than 2 ° C / min, the temperature is increased to 500 ° C. The fine compound precipitated at this time is again dissolved in the copper matrix and the growth of the originally existing compound is not suppressed.

  In the present invention, after the temperature rise, heat treatment is performed at a final temperature (900 to 1050 ° C.) for 0.5 to 12 hours. When the final ultimate temperature is lower than 900 ° C., the coarse compound does not completely dissolve in the copper matrix, but partially remains, and when it is higher than 1050 ° C., the plate shape after processing deteriorates. When the homogenization heat treatment time is shorter than 0.5 hour, the coarse compound cannot be completely dissolved in the copper matrix and partially remains. The upper limit of the homogenization heat treatment time is about 12 hours, at which the solid solution of the coarse compound is almost saturated.

<Hot processing>
The ingot immediately after the homogenization heat treatment is hot-worked (hot rolled or the like) at a working rate of 15 to 95% in a temperature range of 850 to 1000 ° C. Conventionally, after hot working, water cooling is performed in consideration of the formation of coarse precipitates during cooling. However, in the present invention, water cooling is performed after cooling to 750 ° C. at a cooling rate of 0.1 to 10 ° C./second. The particle size and amount of coarse precipitates that become particles A in the final product can be controlled. When the cooling rate to 750 ° C. is smaller than 0.1 ° C./second, the growth of coarse precipitates is remarkable, and the amount of alloy elements in a solid solution state remaining in the copper matrix phase is reduced. Since a sufficient amount of particles B cannot be obtained, sufficient strength, fatigue resistance, and stress relaxation characteristics cannot be obtained in the final product. On the other hand, when the temperature is higher than 10 ° C./second, coarse precipitates are hardly formed, the amount of particles A in the final product is reduced, and improvement in fatigue resistance cannot be expected.

<Chamfer>
The oxide film formed on the surface of the material after hot working is removed by chamfering. The chamfering can be performed by a known method.

<Cold processing>
The material after chamfering is cold-worked (cold rolling or the like) at a processing rate of 70 to 90%. In this step, the strength of the material is increased, the plate thickness is reduced, and coarse precipitates precipitated in the copper matrix after hot working are stretched.

<Aging heat treatment>
The material after cold rolling is subjected to an aging heat treatment at 400 to 500 ° C. for 10 minutes to 24 hours. By the aging heat treatment, fine precipitates are precipitated in the copper matrix, and the strength, conductivity, fatigue resistance, and stress relaxation characteristics are improved. When the treatment is performed at a low temperature for a short time, the amount of precipitation is small, and the particle diameter of the precipitated compound is too fine, so that improvement in strength, conductivity, fatigue resistance, and stress relaxation resistance cannot be expected. In addition, when treated at a high temperature for a long time, the deposited compounds become coarse and the number of compounds per unit volume is reduced, so that the conductivity is improved, but the improvement in strength, fatigue resistance, and stress relaxation characteristics cannot be expected. . Further, in some cases, recrystallization of the structure proceeds and the strength is significantly reduced. Moreover, it is preferable that the cooling rate to 300 degreeC after an aging heat processing shall be 1-2 degreeC / min. By setting the cooling rate to 300 ° C. within this range, the strength, conductivity, fatigue resistance, and stress relaxation characteristics can be further improved.

<Finish processing>
Finishing processing (such as finish rolling) may be performed on the material after aging heat treatment at a processing rate of 0 to 50%. Here, the processing rate of 0% means that finish processing is not performed. Finishing improves strength and fatigue resistance, but decreases conductivity and stress relaxation characteristics. In addition, coarse precipitates stretched by cold working are further stretched by finishing. When the processing rate of finishing is larger than 50%, the conductivity and the stress relaxation resistance are remarkably deteriorated. By adjusting the total processing rate of the material from chamfering to finish rolling to 70 to 90%, the aspect ratio of coarse precipitates generated by cooling after hot working is adjusted to a range defined by particles A. be able to. When the total processing rate is less than 70%, the aspect ratio of the coarse precipitates after processing is small, so that the fatigue resistance is improved when a beam whose longitudinal direction is parallel to the rolling direction is vibrated. In addition, it is difficult to obtain a desired strength. When the total processing rate is greater than 90%, the aspect ratio of the coarse precipitate after processing becomes large, and the fatigue resistance characteristics when the beam whose longitudinal direction is perpendicular to the rolling direction is vibrated are impaired.

<Strain relief annealing>
The material after finishing may be subjected to strain relief annealing at 300 to 600 ° C. for 10 seconds to 12 hours. When strain relief annealing is performed, the strength decreases, but the conductivity and stress relaxation resistance are restored. Even if it is processed at a low temperature for a short time, these characteristics hardly change, and when it is processed at a high temperature for a long time, the strength is remarkably lowered.

  The copper alloy sheet of the present invention has strength, conductivity, fatigue resistance, and stress relaxation characteristics, and includes automotive parts such as EV and HEV, peripheral infrastructure, connectors for solar power generation systems, and other lead frames. Suitable for relays, switches, sockets and the like.

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

  The raw material was melted and cast to produce an ingot, 60% hot processing was performed at 850 ° C. to 1000 ° C. immediately after a predetermined homogenization heat treatment, and the cooling rate was controlled to 750 ° C., followed by water cooling. After cooling with water, the oxide film of the material was removed by chamfering, followed by cold working, aging heat treatment, and cooling at a cooling rate of 1 ° C./min. After cooling, finish rolling with a processing rate of 25% and continuous strain relief annealing at 350 ° C. for 30 minutes were performed to obtain a material. By keeping the conditions of each step within a specified range, a sample of the invention example having a target material structure was obtained. As a comparative example, materials with different ingot components and production conditions were produced.

  In addition, after each heat treatment and rolling, acid cleaning and surface polishing were performed according to the state of oxidation and roughness of the material surface.

  The following evaluation was performed on the specimens thus prepared.

(Measurement of particle A)
Particles A were observed with a scanning electron microscope (SEM), and the number was confirmed. After the final product is wet-polished and buffed in a cross section parallel to the rolling direction (RD), and the polished surface is corroded for several seconds with a liquid mixed at a ratio of chromic acid: water = 1: 1 (volume ratio). , And observed and measured with a SEM at a magnification of 50 to 5000 times.
Regarding the aspect ratio, in the observed compound, the major axis a having the largest diameter and the minor axis b having the smallest diameter passing through the center of gravity of the particle were measured, and a / b was calculated. did. A compound having an aspect ratio of more than 2 and less than 5 and a minor axis b of 100 nm or more was designated as particle A, and the number of particles A contained in a range of 0.1 mm ² was counted and further converted to the number of particles per mm ² . The particle component was confirmed by an energy dispersive X-ray spectrometer (EDS) attached to the SEM.

(Measurement of particle B)
Particle B was observed with a transmission electron microscope (TEM), and the number thereof was confirmed. The material immediately after the aging heat treatment in which the number of particles B in the copper matrix is determined and the strain amount is the smallest is electropolished with a methanol solution of 20% nitric acid to obtain a sample for observation. Observation and measurement were performed at a magnification of × 100,000. A compound having a particle diameter of 5 to 50 nm was defined as particle B, and the number of particles B contained in a range of 0.25 μm ² was counted and further converted to the number of particles per 1 mm ² . The particle component was confirmed by EDS attached to TEM.

(Tensile strength)
Three test pieces of JIS Z2201-13B cut out from the rolling parallel direction were measured according to JIS Z2241, and the average value was shown.

(conductivity)
In a constant temperature bath maintained at 20 ° C. (± 0.5 ° C.), the specific resistance was measured by the four probe method, and the conductivity was calculated. In addition, the distance between terminals was 100 mm.

(Fatigue resistance)
In accordance with Japan Copper and Brass Association JCBA T308: 2001 (provisional) "Fatigue property test method for copper and copper alloy sheet strip", a double-bending plane bending fatigue test was performed. Set the maximum bending stress to be applied, perform the test 4 times, and if the average number of vibrations when the test piece breaks is 10 ⁶ or more, fatigue resistance is good (○), and the case is less than 10 ⁶ (X) was judged. The test piece was a strip having a width of 10 mm. Fatigue resistance in the rolling parallel direction when the rolling parallel direction matches the length direction of the test piece, and fatigue resistance in the rolling vertical direction when the rolling parallel direction and the length direction of the test piece are in a vertical relationship Characteristic. The maximum bending stress to be applied was 300 MPa in the rolling parallel direction and 250 MPa in the rolling vertical direction.

(Stress relaxation rate)
In accordance with Japan Copper and Brass Association JCBA T309: 2004 “Stress Relaxation Test Method by Bending Copper and Copper Alloy Sheet Strips”, the measurement was carried out at 150 ° C. for 1000 hours as shown below. By the cantilever method (using a cantilever block type jig), 80% of the proof stress was applied as the initial maximum stress. The test piece was a strip having a width of 10 mm, and the parallel direction of rolling and the length direction of the test piece were matched.

  Table 1 summarizes the alloy components of the produced ingots. Alloys 1-26 are within the scope of the present invention, and alloys 27-37 are out of range.

  Table 2 shows the inventive examples in which the production method is within the scope of the present invention and the components are also within the scope of the present invention, and the comparative examples in which the components are outside the scope of the present invention. The invention example in which both the component and the production method are within the scope of the present invention is a copper alloy sheet having the material structure defined in the present invention and excellent in conductivity and fatigue resistance in the rolling parallel direction. By adding alloy components, tensile strength ≧ 500 MPa, conductivity ≧ 75% IACS, stress relaxation rate ≦ 30%, and good fatigue resistance in the rolling parallel direction, strength, conductivity, stress relaxation It is possible to produce a copper alloy sheet having both properties and fatigue resistance. On the other hand, in the comparative example in which the addition amount of the alloy component is less than the range specified in the present invention, the effect of adding the alloy component is not sufficient, and the material characteristics are almost the same as those of the non-added invention example. Moreover, in the comparative example in which the addition amount exceeds the upper limit of the range specified in the present invention, any of conductivity, fatigue resistance, and workability was inferior.

  Table 3 shows an invention example in which the components are within the scope of the present invention and the production conditions are also within the scope of the present invention, and a comparative example in which the production conditions are outside the scope of the present invention. Inventive examples whose components and production methods are both within the scope of the present invention have the material structure defined in the present invention, and have strength, conductivity, stress relaxation resistance, and fatigue resistance characteristics in both the parallel and vertical directions of rolling. Is a copper alloy sheet material. On the other hand, the comparative example whose manufacturing conditions are outside the scope of the present invention is inferior in conductivity, fatigue resistance, and workability, and has strength, conductivity, stress relaxation resistance, fatigue resistance, and workability. I can't.

  All copper alloy sheets within the scope of the present invention are excellent in electrical conductivity and fatigue resistance, and can have strength, electrical conductivity, stress relaxation resistance, and fatigue resistance by adding alloy elements, It is suitable for in-vehicle components such as EV and HEV, connectors for peripheral infrastructure and solar power generation systems, other lead frames, relays, switches, sockets and the like.

Claims (6)

Cr is 0.10 to 0.50 mass%, Mg is 0 to 0.20 mass%, and at least one of Zr and Ti is 0 to 0.20 mass% in total, Zn, Sn, Ag, Si, Fe A copper alloy sheet material containing a total of at least one of 0 to 0.40 mass%, the balance being Cu and inevitable impurities,
When observing a parallel section in the processing direction, particles having an aspect ratio a / b obtained by dividing the major axis “a” of the particle diameter by the minor axis “b” is greater than 2 and less than 5, and the minor axis “b” is 100 nm or more. A copper alloy sheet characterized by the presence of ¹ to 1 × 10 ³ / mm ² . The copper matrix phase contains 1 × 10 ⁹ to 1 × 10 ¹² particles / mm ^{2 of} an alloy component having a particle diameter of 5 to 50 nm or a compound containing an alloy component. The copper alloy sheet material described.   The copper alloy sheet according to claim 1, wherein Mg is contained in the copper matrix phase in an amount of 0.01 to 0.20 mass%.   The copper alloy sheet according to any one of claims 1 to 3, wherein the copper matrix phase contains at least one of Zr and Ti in a total amount of 0.01 to 0.20 mass%.   The copper matrix phase contains at least one of Zn, Sn, Ag, Si, and Fe in a total amount of 0.01 to 0.40 mass%, according to any one of claims 1 to 4. Copper alloy sheet material. It is a manufacturing method of the copper alloy sheet material according to any one of claims 1 to 5,
The ingot obtained by melting and casting the copper alloy component is subjected to (a) homogenization heat treatment at a temperature rising rate from room temperature to 500 ° C. of 5 ° C./min or less, and then 900 ° C. at a rate of 2 ° C./min or more. (B) Hot working is performed in the temperature range of 850 to 1000 ° C. (c) After hot working, 0.1 to 750 ° C. After cooling at a cooling rate of 10 ° C./second, water cooling, chamfering, (d) after cold working at a processing rate of 70-90% (e) aging at 400-500 ° C. for 10 minutes to 24 hours (F) A method for producing a copper alloy sheet material, wherein heat treatment is performed, and (f) finishing is performed in an amount of 0 to 50% so that the total processing rate of the material after the chamfering is 70 to 90%.