JP6900137B1 - Copper alloy plate material and its manufacturing method, and members for electrical and electronic parts - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a copper alloy plate material having excellent burring workability even when burring is performed under difficult processing conditions while sufficiently exhibiting strength and conductivity, a method for producing the same, and a member for electric / electronic parts. A copper alloy plate contains 0.10-0.80% by mass of Cr, the balance has a composition of Cu and unavoidable impurities, has a tensile strength of 350-800 MPa, a conductivity of 55-90% IACS, and in the rolling direction. On the other hand, the average crystal grain size A0 °, A45 ° and A90 ° in the plate thickness direction of the cross section cut out in the 0 °, 45 ° and 90 ° directions are all 10.0 μm or less, the standard deviation of A0 ° and A45. The average value of the standard deviation of ° and the standard deviation of A90 ° is 2.0 μm or less, Bm = 100 (Am-C) / C (m is 0 °, 45 °, 90 °, C is A0 ° and A45 °. And the average value of A90 °), the deviation of A0 ° is B0 °, the deviation of A45 ° is B45 °, and the deviation of A90 ° is B90 °, which is 10.0% or less. [Selection diagram] Fig. 1

Description

The present invention relates to a copper alloy plate material, a method for producing the same, and a member for electric / electronic parts.

In general, copper alloy plate materials used for connectors for electronic devices and shield cases for automobiles are subjected to press working such as punching, bending, drawing, and overhanging, and burring (hole flange processing).

In addition, with the recent improvement in the performance of electronic devices and in-vehicle devices, the mechanical and electrical characteristics of copper alloy plates used for members for electrical and electronic components that make up electrical and electronic devices, as well as electrical and electronic components. With the weight reduction and complicated shape of the members, it is required that the workability of the copper alloy plate material to the target shape is compatible at a higher level.

For example, Patent Document 1 contains 0.1 to 0.6% by mass of Cr, 0.01 to 0.30% by mass in total of one or two of Zr and Ti, and the balance is copper and unavoidable. Described is a copper alloy plate in which ^{1000 to 10000,000 second phase particles having a particle size of 0.1 μm or more are present / mm 2} among the second phase particles which are composed of target impurities and are present in the matrix phase.

In Patent Document 1, by controlling the number of second phase particles of a Cu—Cr alloy, it has high strength, high conductivity, and bendability. However, the burring process for enlarging a circular hole is completely different from the bending process. Therefore, in a copper alloy plate in which the number of second phase particles of a Cu—Cr alloy as in Patent Document 1 is controlled, the copper alloy plate is used. Insufficient burring workability.

Further, with respect to the copper alloy plate material manufactured by the conventional method, although the burring process can be performed under difficult conditions, it is necessary to sacrifice the mechanical properties and the electrical properties. Machining under difficult conditions means, for example, to increase the hole flange height of the burring hole, to increase the hole expansion rate of the burring hole, or to shorten the punch stroke to improve productivity. , The tip angle of the hole expansion punch is increased with respect to the punch stroke.

In this way, it is excellent even if burring is performed under difficult conditions in the process of processing to the target shape without sacrificing the balance of strength and conductivity required for members for electrical and electronic parts in recent years. There is a demand for a copper alloy plate material having burring workability.

JP-A-2018-154910

An object of the present invention is to obtain a copper alloy plate material having excellent burring workability and a manufacturing method thereof, and a member for electric / electronic parts, even if burring processing is performed under difficult processing conditions while sufficiently exhibiting strength and conductivity. To provide.

The gist structure of the present invention is as follows.
[1] It contains Cr in an amount of 0.10% by mass or more and 0.80% by mass or less, has an alloy composition in which the balance is Cu and unavoidable impurities, has a tensile strength of 350 MPa or more and 800 MPa or less, and a conductivity of 55% IACS or more. _{90% IACS or less, average crystal grain size A 0 ° in the plate thickness direction in the cross section S 0 °} cut out in the 0 ° direction with respect to the rolling direction, average in the plate thickness direction in _{the cross section S 45 °} cut out in the 45 ° direction _{The average crystal grain size A 90 °} in the plate thickness direction in the crystal grain size A _{45 ° and the cross section S 90 °} cut out in the 90 ° direction is 10.0 μm or less, and the standard deviation of _{A 0 ° , A 45.} mean value of the standard deviation of the standard deviation and a _{90 °} of _° is, 2.0 .mu.m or less, represented by the following formula (1), wherein the average crystal grain size a ₀ anisotropically degree B _{0 °} of _°, the average crystal A copper alloy plate material characterized in that the heterogeneity B _{45 ° having} a particle size A _{45 ° and the heterogeneity B 90 ° having} an average crystal particle size A _{90 ° are both 10.0% or less.}
B _m = 100 × ( _Am −C) / C ・ ・ ・ Equation (1)
However, in the above formula (1), m is 0 °, 45 ° or 90 °, and C is the average value of _{A 0 °} , A _{45 °} and A _{90 ° ((A 0 °} + A _{45 °} + A _{90). °} ) / 3).
[2] The sectional S ₀ mean crystal grain size D _{0 °} in the rolling direction in _° is less than 15.0 .mu.m, the copper alloy sheet according to [1].
[3] The average KAM value E _{0 °} in the cross-section S _{0 °,} the average KAM value _{E 45 °} in the cross-section _{S 45 °,} and the average KAM value _{E 90 °} in the cross-section _{S 90 °} are both 10.0 ° Below, _{the average value of the standard deviation of E 0 °,} the standard deviation of E _{45 °} , and the standard deviation of E _{90 °} is 3.0 ° or less, and the average KAM value E represented by the following equation (2). ₀ anisotropic degree F _{0 °} of _°, the average KAM value anisotropic degree _{F 45 °} of _{E 45 °,} and the average KAM value anisotropic degree _{F 90 °} of _{E 90 °} are both 10.0% below The copper alloy plate material according to the above [1] or [2].
F _m = 100 × (E _m −G) / G ・ ・ ・ Equation (2)
However, in the above equation (2), m is 0 °, 45 ° or 90 °, and G is the average value of _{E 0 °} , E _{45 °} and E _{90 ° ((E 0 °} + E _{45 °} + E _{90). °} ) / 3).
[4] It contains Cr in an amount of 0.10% by mass or more and 0.80% by mass or less, has an alloy composition in which the balance is Cu and unavoidable impurities, has a tensile strength of 350 MPa or more and 800 MPa or less, and a conductivity of 55% IACS or more. 90% IACS or less, relative to the rolling direction, 0 ° mean KAM value E _{0 °} in cross-section S _{0 °} cut in a direction, the average KAM value _{E 45 °} in the cross-section _{S 45 °} cut in the direction of 45 °, and 90 ° mean KAM value _{E 90 °} in the cross-section _{S 90 °} cut in the direction are both 10.0 ° below and E ₀ standard deviation _°, the average value of the standard deviation and the standard deviation of _{E 90 °} of _{E 45 °} Is 3.0 ° or less, which is represented by the following formula (2), that is, the average KAM value E _{0 °} of the _{eccentricity F 0 °} , the average KAM value E _{45 °} of the _{eccentricity F 45 °} , and the above. A copper alloy plate material characterized in that the average KAM value E _{90 ° and} the heterogeneity F _{90 ° are all 10.0% or less.}
F _m = 100 × (E _m −G) / G ・ ・ ・ Equation (2)
However, in the above equation (2), m is 0 °, 45 ° or 90 °, and G is the average value of _{E 0 °} , E _{45 °} and E _{90 ° ((E 0 °} + E _{45 °} + E _{90). °} ) / 3).
[5] The alloy composition further comprises 0.05% by mass or more and 2.50% by mass or less in total of one or more elements selected from the group consisting of Mg, Ti, Co, Zr, Zn, Sn and Si. The copper alloy plate material according to any one of the above [1] to [4], which is contained.
[6] The copper alloy plate material according to any one of the above [1] to [5], which has a thickness of 0.05 mm or more and 0.50 mm or less.
[7] The method for producing a copper alloy plate according to any one of the above [1] to [6], wherein a casting step (step 1), a homogenizing heat treatment step (step 2), and a homogenizing heat treatment step (step 2) are applied to the copper alloy material. Hot rolling process (process 3), surface milling process (process 4), cold rolling process (process 5), intermediate heat rolling process (process 6), finishing cold rolling process (process 7) and tempering annealing process (process). 8) is applied in this order, and the ratio (T6) of the maximum temperature T6 (° C.) of the heat-treated material in the intermediate heat treatment step (step 6) to the processing rate R5 (%) of the rolled material in the cold rolling step (step 5). / R5) is 8.0 or more and 20.0 or less, the maximum temperature T6 is 400 ° C. or more and 650 ° C. or less, and the following in a pair of work rolls provided in each pass of the finish cold rolling step (step 7). The ratio (T8 / M7) of the maximum temperature T8 (° C.) of the annealed material in the tempering and annealing step (step 8) to the average value M7 of each pass of the roll gap shape ratio represented by the formula (3) is 10. A method for producing a copper alloy plate, characterized in that the maximum temperature T8 is 250 ° C. or higher and 700 ° C. or lower.
M7 = 3 × {r (h ₁ −h ₂ )} ^1/2 / {n (h ₁ + 2h ₂ )} ... Equation (3)
However, in the formula (3), r is the radius (mm) of the work roll, and h ₁ is the thickness (mm) of the rolled material before each pass in the finish cold rolling step (step 7). Yes, h ₂ is the thickness (mm) of the rolled material after each pass of the finish cold rolling step (step 7), and n is the total number of passes of the finish cold rolling step (step 7). Is.
[8] A member for an electric / electronic component, wherein the copper alloy plate material according to any one of the above [1] to [6] has a burring hole.
[9] The burring hole is the member for electrical / electronic parts according to the above [8], wherein the hole expansion ratio λ represented by the following formula (4) is 20% or more.
λ = 100 × (dd ₀ ) / d ₀ ... Equation (4)
However, in the above formula (4), d ₀ is the diameter (mm) of the hole before the hole expansion process, and d is the diameter (mm) of the burring machined hole after the hole expansion process.

According to the present invention, a copper alloy plate material having excellent burring workability, a manufacturing method thereof, and a member for electric / electronic parts can be obtained even if burring is performed under difficult processing conditions while sufficiently exhibiting strength and conductivity. Can be provided.

FIG. 1 is a diagram for explaining a _{cross section S 0 °} , a cross section S _{45 °,} and a cross section S _{90 ° of a copper alloy plate material.} FIG. 2 is a diagram for explaining an average value M7 of the roll gap shape ratio in the finish cold rolling step (step 7). FIG. 3 is a schematic cross-sectional view showing an example of punching in burring. FIG. 4 is a schematic cross-sectional view showing an example of hole expansion in burring.

Hereinafter, the present invention will be described in detail based on the embodiments.

As a result of intensive research, the present inventors have determined the strength and the KAM value corresponding to the crystal grain size and the amount of local strain of the copper alloy plate, and their uniformity and heterogeneity with high precision. It has been found that excellent burring workability can be obtained even if burring processing is performed under difficult processing conditions without impairing the balance of conductivity, and the present invention has been completed based on such findings.

The copper alloy plate material of the embodiment has an alloy composition containing Cr in an amount of 0.10% by mass or more and 0.80% by mass or less, the balance being Cu and unavoidable impurities, a tensile strength of 350 MPa or more and 800 MPa or less, and conductivity. in the 55% IACS or more 90% IACS or less, relative to the rolling direction, 0 ° direction average plate thickness direction in the cross section S _{0 °} cut in the grain size a _{0 °,} sectional _{S 45 °} cut in the 45 ° direction The average crystal grain size A _{45 °} in the plate thickness direction and the average crystal grain size A _{90 ° in the plate thickness direction in the cross section S 90 °} cut out in the 90 ° direction are both 10.0 μm or less and A _{0 °} . standard deviation, the mean value of the standard deviation of the standard deviation and _{a 90 °} of _{a 45 °} is, 2.0 .mu.m or less, represented by the following formula (1), wherein the average crystal grain size a ₀ anisotropically of _{B 0} of _{° °,} the average crystal grain anisotropically size _{B 45 °} of diameter _{a 45 °,} and the average grain anisotropy of the diameter _{a 90 ° B 90 °} are both less 10.0%.

B _m = 100 × ( _Am −C) / C ・ ・ ・ Equation (1)

In the above formula (1), m is 0 °, 45 ° or 90 °, and C is the average value of _{A 0 °} , A _{45 °} and A _{90 ° ((A 0 °} + A _{45 °} + A _{90 °} )). / 3).

Further, the copper alloy plate material of the embodiment has an alloy composition containing Cr in an amount of 0.10% by mass or more and 0.80% by mass or less, the balance being Cu and unavoidable impurities, and having a tensile strength of 350 MPa or more and 800 MPa or less. The conductivity is 55% IACS or more and 90% IACS or less, the average KAM value in _{the cross section S 0 ° cut out in the 0 ° direction with respect to the rolling direction E 0 °} , and the average KAM value in _{the cross section S 45 °} cut out in the 45 ° direction. E _{45 °,} and 90 ° is an average KAM value _{E 90 °} in the cross-section _{S 90 °} cut in a direction, either 10.0 ° or less, and the standard deviation of E _{0 °,} the standard deviation and _{E E 45 ° 90} mean value of _° the standard deviation of, 3.0 ° or less, represented by the following formula (2), the average KAM value E ₀ anisotropic degree F _{0 °} of _°, anisotropic in the average KAM value _{E 45 °} degrees _{F 45 °,} and the average KAM value anisotropic degree _{F 90 °} of _{E 90 °} are both less 10.0%.

F _m = 100 × (E _m −G) / G ・ ・ ・ Equation (2)

In the above equation (2), m is 0 °, 45 ° or 90 °, and G is the average value of _{E 0 °} , E _{45 °} and E _{90 ° ((E 0 °} + E _{45 °} + E _{90 °} )). / 3).

First, the alloy composition of the copper alloy plate material will be described.

The copper alloy plate material of the above embodiment has an alloy composition in which Cr is contained in an amount of 0.10% by mass or more and 0.80% by mass or less, and the balance is Cu and unavoidable impurities.

<Cr: 0.10% by mass or more and 0.80% by mass or less>
Cr (chromium) is an element necessary for increasing the strength of the copper alloy plate material, and it is necessary to contain Cr in an amount of 0.10% by mass or more and 0.80% by mass or less. When the Cr content is 0.10% by mass or more, the strength of the copper alloy plate material is increased and the burring workability is improved. Further, when the Cr content is 0.80% by mass or less, coarse crystallized products containing Cr are less likely to be generated during the casting process, and the burring workability is improved. Therefore, the lower limit of the Cr content is 0.10% by mass, preferably 0.2% by mass, more preferably 0.3% by mass, and the upper limit of the Cr content is 0.80% by mass. %, Preferably 0.7% by mass, more preferably 0.6% by mass.

<Auxiliary component of copper alloy plate: 0.05% by mass or more and 2.50% by mass or less>
The alloy composition of the copper alloy plate further comprises 0.05% by mass or more and 2.50% by mass or less in total of one or more elements selected from the group consisting of Mg, Ti, Co, Zr, Zn, Sn and Si. Can be contained. That is, the copper alloy plate material is one kind selected from the group consisting of Mg, Ti, Co, Zr, Zn, Sn and Si as a sub-component which is an optional component in addition to Cr which is an essential basic component. The above components can be contained in a total amount of 0.05% by mass or more and 2.50% by mass or less. When the content of the auxiliary component is 0.05% by mass or more, the strength of the copper alloy plate material is improved, and the effect of delaying recrystallization in the hot rolling process and recrystallization in the intermediate heat treatment process is exhibited, and copper is exhibited. The crystal grain size and KAM value, which are the crystalline states of the alloy plate material, and their uniformity and heterogeneity can be easily controlled within a predetermined range, and the burring workability can be improved. Further, when the content of the sub-component is 2.50% by mass or less, the decrease in the conductivity of the copper alloy plate material can be suppressed. Therefore, the lower limit of the content of the sub-component is preferably 0.05% by mass, more preferably 0.30% by mass, still more preferably 0.50% by mass, and the upper limit of the content of the sub-component is. It is preferably 2.50% by mass, more preferably 2.20% by mass, and even more preferably 1.90% by mass.

<Mg: 0.05% by mass or more and 0.20% by mass or less>
When the content of Mg (magnesium) is 0.05% by mass or more, the effect of solid solution strengthening the copper alloy plate material is exhibited. When the Mg content is 0.20% by mass or less, a decrease in the conductivity of the copper alloy plate material can be suppressed. Therefore, the lower limit of the Mg content is preferably 0.05% by mass, and the upper limit of the Mg content is preferably 0.20% by mass.

<Ti: 0.05% by mass or more and 0.20% by mass or less>
When the Ti (titanium) content is 0.05% by mass or more, it dissolves in the copper alloy plate material and raises the recrystallization temperature of the copper alloy plate material, thereby causing dynamic recrystallization in the hot rolling process. It has the effect of suppressing grain coarsening. When the Ti content is 0.20% by mass or less, the amount of decrease in the conductivity of the copper alloy plate material can be suppressed to a level at which the heat dissipation required for the shield case or the like can be secured at the minimum. Therefore, the lower limit of the Ti content is preferably 0.05% by mass, and the upper limit of the Ti content is preferably 0.20% by mass.

<Co: 0.05% by mass or more and 1.50% by mass or less>
When the Co (cobalt) content is 0.05% by mass or more, the strength of the copper alloy plate material increases. If the Co content is more than 1.50% by mass, the conductivity of the copper alloy plate material is lowered and the metal cost is increased. Therefore, the lower limit of the Co content is preferably 0.05% by mass, and the upper limit of the Co content is preferably 1.50% by mass.

<Zr: 0.05% by mass or more and 0.20% by mass or less>
When the Zr (zirconium) content is 0.05% by mass or more, coarsening of dynamically recrystallized grains during hot rolling is suppressed, which contributes to improvement in the strength of the copper alloy plate material. If the Zr content is more than 0.20% by mass, coarse crystallization may occur during the casting process, which may be the starting point of fracture during the burring process. Therefore, the lower limit of the Zr content is preferably 0.05% by mass, and the upper limit of the Zr content is preferably 0.20% by mass.

<Zn: 0.05% by mass or more and 0.60% by mass or less>
When the Zn (zinc) content is 0.05% by mass or more, the adhesion and migration characteristics of Sn plating and solder plating can be improved. When the Zn content is 0.60% by mass or less, a decrease in the conductivity of the copper alloy plate material can be suppressed, and sufficient heat dissipation can be obtained. Therefore, the lower limit of the Zn content is preferably 0.05% by mass, and the upper limit of the Zn content is preferably 0.60% by mass.

<Sn: 0.05% by mass or more and 0.30% by mass or less>
When the Sn (tin) content is 0.05% by mass or more, the effect of solid solution strengthening the copper alloy plate material is exhibited. When the Sn content is 0.30% by mass or less, a decrease in the conductivity of the copper alloy plate material can be suppressed. Therefore, the lower limit of the Sn content is preferably 0.05% by mass, and the upper limit of the Sn content is preferably 0.30% by mass.

<Si: 0.02% by mass or more and 0.40% by mass or less>
When the content of Si (silicon) is 0.02% by mass or more, other additive elements such as Co, Mg, Cr, and Si compounds are formed, and the strength of the copper alloy plate material is increased. When the Si content is 0.40% by mass or less, it is possible to suppress a decrease in the thermal conductivity of the copper alloy plate material, and sufficient heat dissipation can be obtained. Therefore, the lower limit of the Si content is preferably 0.02% by mass, and the upper limit of the Si content is preferably 0.40% by mass.

<Remaining: Cu and unavoidable impurities>
The rest other than the components mentioned above are Cu (copper) and unavoidable impurities. The unavoidable impurity is unavoidably mixed in the manufacturing process and is originally unnecessary, but it is an allowable impurity component because it is a trace amount and does not affect the characteristics of the copper alloy plate material. The smaller the content of unavoidable impurities, the more preferable. Examples of unavoidable impurities include Bi (bismuth), Se (selenium), As (arsenic), Ag (silver) and the like. The upper limit of the content of these components is preferably 0.03% by mass for each of the above components, and preferably 0.10% by mass for the total amount of the above components.

Next, the tensile strength of the copper alloy plate material will be described.

The tensile strength of the copper alloy plate material is 350 MPa or more and 800 MPa or less. When the tensile strength of the copper alloy plate material is 350 MPa or more, the strength is improved, so that it can also protect electrical and electronic devices such as a shield case, a camera module, and a battery pack case provided with the copper alloy plate material. Heat dissipation is improved. Further, when the tensile strength of the copper alloy plate material is 800 MPa or less, deterioration of heat dissipation and workability of the copper alloy plate material can be suppressed. Therefore, the lower limit of the tensile strength is 350 MPa, preferably 370 MPa, more preferably 400 MPa, and the upper limit of the tensile strength is 800 MPa, preferably 750 MPa, more preferably 700 MPa.

The tensile strength of the copper alloy plate material can be measured by performing a tensile test based on JIS Z 2241: 2011 using a JIS 13B test piece. The tensile strength of the copper alloy plate material shall be the tensile strength in the direction parallel to rolling.

Next, the conductivity of the copper alloy plate material will be described.

The conductivity of the copper alloy plate is 55% IACS or more and 90% IACS or less. Thermal conductivity can be calculated from conductivity according to Wiedemann-Franz law, and if the temperature is constant, it may be proportional to conductivity regardless of the type of metal. Are known. Therefore, when the conductivity of the copper alloy plate material is 55% IACS or more, it is possible to have a high thermal conductivity. As a result, electric / electronic devices such as a shield case, a camera module, and a battery pack case provided with the copper alloy plate material. Has excellent heat dissipation. Further, when the conductivity of the copper alloy plate material is 90% IACS or less, the strength of the copper alloy plate material required as a member for electric / electronic parts mounted on those electric / electronic devices can be secured at the minimum. .. Therefore, the lower limit of conductivity is 55% IACS, preferably 60% IACS, and the upper limit of conductivity is 90% IACS. As described above, the higher the conductivity of the copper alloy plate material, the more preferable it is.

The conductivity of the copper alloy plate material can be calculated by measuring the specific resistance by the 4-terminal method in a constant temperature bath kept at 20 ° C. (± 0.5 ° C.) with a distance between terminals of 100 mm.

Next, the average crystal grain size A and the anisotropy B of the copper alloy plate material will be described.

As shown in FIG. 1, the average crystal grain size A _{0 ° in the plate thickness direction in the cross section S 0 °} cut out in the 0 ° direction with respect to the rolling direction of the copper alloy plate material 10 is 10.0 μm or less. Further, the average crystal grain size A _{45 ° in the plate thickness direction in the cross section S 45 °} cut out in the 45 ° direction with respect to the rolling direction is 10.0 μm or less. Further, the average crystal grain size A _{90 ° in the plate thickness direction in the cross section S 90 °} cut out in the 90 ° direction with respect to the rolling direction is 10.0 μm or less. When the average crystal grain size A _{0 °} , the average crystal grain size A _{45 °,} or the average crystal grain size A _{90 °} is larger than 10.0 μm, the sheared surface and the fracture surface in the fracture surface of the through hole formed by press punching The interface becomes non-uniform and induces cracks during hole expansion. From the viewpoint of improving burring workability, the average crystal grain size A _{0 °} , the average crystal grain size A _{45 °,} and the average crystal grain size A _{90 °} are all 10.0 μm or less, preferably 8.0 μm or less, and more. It is preferably 5.0 μm or less. As described above, the smaller the average crystal grain size is, the more preferable.

The average value of the standard deviation of the average crystal particle diameter A _{0 °} , the standard deviation of the average crystal particle diameter A _{45 °} , and the standard deviation of the average crystal particle diameter A _{90 °} is 2.0 μm or less. When the average value calculated by averaging the standard deviations of these average crystal grain sizes is larger than 2.0 μm, the variation in crystal grain size is large, and the shear surface and fracture surface of the fracture surface of the through hole formed by press punching are large. The interface with and is non-uniform, which induces cracks during hole expansion. From the viewpoint of improving the burring workability, the average value of the standard deviations of the average crystal grain size is 2.0 μm or less, preferably 1.8 μm or less, and more preferably 1.0 μm or less. As described above, the smaller the average value of the above standard deviations is, the more preferable it is.

Further, the anisotropy B _{0 ° of the average crystal grain size A 0 °} represented by the above formula (1) is 10.0% or less. The anisotropy B _{45 ° of the average crystal grain size A 45 °} represented by the above formula (1) is 10.0% or less. The anisotropy B _{90 ° of the average crystal grain size A 90 °} represented by the above formula (1) is 10.0% or less. When the anisotropy B _{0 °} , the anisotropy B _{45 °} or the anisotropy B _{90 °} is greater than 10.0%, the interface between the sheared surface and the fracture surface in the fracture surface of the through hole formed by press punching becomes. It becomes non-uniform and induces cracks during hole expansion. From the viewpoint of improving the burring workability, the anisotropy B _{0 °} , the _{anisotropy B 45 °} and the anisotropy B _{90 °} are all 10.0% or less, preferably 8.0% or less, more preferably. Is 5.0% or less. As described above, the smaller the anisotropy is, the more preferable it is.

Further, as shown in FIG. 1, the average crystal grain size D _{0 °} in the rolling direction of the copper alloy plate 10 in the cross section S _{0 °} cut out in the 0 ° direction with respect to the rolling direction is preferably 15.0 μm or less. More preferably, it is 13.0 μm or less. When the average crystal grain size D _{0 °} is larger than 15.0 μm, deep wrinkles in the rolling direction are likely to occur at the base (bent portion) of the hole flange formed after the hole expansion process, and cracks are induced. As described above, the smaller the average crystal grain size D _{0 °} is, the more preferable.

The crystal grain size is analyzed from the crystal orientation data continuously measured using the EBSD detector attached to the high-resolution scanning analytical electron microscope (JSM-7001FA, manufactured by Nippon Denshi Co., Ltd.), and the analysis software (OIM Analysis, manufactured by TSL). ) Can be obtained from the crystal orientation analysis data calculated using. "EBSD" is an abbreviation for Electron Backscatter Diffraction, which is a crystal orientation analysis technique using reflected electron Kikuchi line diffraction generated when a copper alloy plate as a sample is irradiated with an electron beam in a scanning electron microscope (SEM). That is. "OIM Analysis" is data analysis software measured by EBSD. As shown in FIG. 1, the measurement areas are a cross section S _{0 ° cut out in the 0 ° direction with respect to the rolling direction, a cross section S 45 °} cut out in the 45 ° direction with respect to the rolling direction, and 90 ° with respect to the rolling direction. _{The cross section S 90 °} cut out in the direction is a surface mirror-finished by electrolytic polishing. The measurement is performed with a step size of 0.1 μm in a field of view having a total plate thickness of 150 μm in width. A crystal grain boundary with an orientation difference of 15 ° or more is defined, and a crystal grain consisting of 2 pixels or more is the target of analysis.

Then, in the obtained IPF image (Inverse Pole Figure), two lines parallel to the plate thickness direction and crossing the plate thickness are drawn at intervals of 50 μm, and the crystal grain size is measured by the cutting method and averaged. The average crystal grain size A is _{0 °} , the average crystal grain size is A _{45 °} , and the average crystal grain size is A _{90 °} . Further, in the obtained IPF image, two vertical lines having a length of 150 μm with respect to the plate thickness direction are drawn at intervals of 25 μm, the crystal grain size is measured by a cutting method, and the average crystal grain size is D _{0. Let °} be. The standard deviation of each average crystal grain size is calculated for each crystal grain on each line.

Next, the average KAM value E and the anisotropy F of the copper alloy plate material will be described.

As shown in FIG. 1, the average KAM value E _{0 ° in the cross section S 0 °} cut out in the 0 ° direction with respect to the rolling direction of the copper alloy plate 10 is 10.0 ° or less. Further, the average KAM value E _{45 ° in the cross section S 45 °} cut out in the 45 ° direction with respect to the rolling direction is 10.0 ° or less. Further, the average KAM value E _{90 ° in the cross section S 90 °} cut out in the 90 ° direction with respect to the rolling direction is 10.0 ° or less. When the average KAM value E _{0 °} , the average KAM value E _{45 °,} or the average KAM value E _{90 °} is larger than 10.0 °, it means that a large amount of strain is accumulated in the copper alloy plate material, and the burring workability is improved. descend. From the viewpoint of improving burring workability, the average KAM value E _{0 °} , the average KAM value E _{45 °,} and the average KAM value E _{90 °} are all 10.0 ° or less, preferably 7.0 ° or less, more preferably. Is 3.0 ° or less. Further, from the viewpoint of material strength, the average KAM value E _{0 °} , the average KAM value E _{45 °,} and the average KAM value E _{90 °} are all preferably 1.0 ° or more.

The average value of the standard deviation of the average KAM value E _{0 °} , the standard deviation of the average KAM value E _{45 °} , and the standard deviation of the average KAM value E _{90 °} is 3.0 ° or less. If the average value calculated by averaging the standard deviations of these average KAM values is larger than 3.0 °, the strain distribution will vary and deformation will tend to concentrate locally during hole expansion, resulting in cracks. Trigger. From the viewpoint of improving the burring workability, the average value of the standard deviations of the average KAM values is 3.0 ° or less, preferably 1.0 ° or less, and more preferably 0.5 ° or less. As described above, the smaller the average value of the above standard deviations is, the more preferable it is.

Further, the anisotropy F _{0 ° of the average KAM value E 0 °} represented by the above formula (2) is 10.0% or less. The anisotropy F _{45 ° of the average KAM value E 45 °} represented by the above formula (2) is 10.0% or less. The anisotropy F _{90 ° of the average KAM value E 90 °} represented by the above formula (2) is 10.0% or less. If the anisotropy F _{0 °} , the anisotropy F _{45 °,} or the anisotropy F _{90 °} is greater than 10.0%, the circumferential anisotropy of the strain distribution is large, and when performing circular hole expansion processing. Induces cracks in. From the viewpoint of improving the burring workability, the anisotropy F _{0 °} , the _{anisotropy F 45 °} and the anisotropy F _{90 °} are all 10.0% or less, preferably 5.0% or less.

The KAM (Kernel Average Measurement) value is an average value of crystal orientation differences between a measurement point and all adjacent measurement points. The KAM value correlates with the dislocation density and corresponds to the amount of lattice strain of the crystal.

The KAM value is analyzed from crystal orientation data continuously measured using the EBSD detector attached to a high-resolution scanning analytical electron microscope (JSM-7001FA, manufactured by Nippon Denshi Co., Ltd.) (OIM Analysis, manufactured by TSL). It can be obtained from the crystal orientation analysis data calculated using. As shown in FIG. 1, the measurement areas are a cross section S _{0 ° cut out in the 0 ° direction with respect to the rolling direction, a cross section S 45 °} cut out in the 45 ° direction with respect to the rolling direction, and 90 ° with respect to the rolling direction. _{The cross section S 90 °} cut out in the direction is a surface mirror-finished by electrolytic polishing. The measurement is performed with a step size of 0.1 μm in a field of view having a total plate thickness of 150 μm in width. A crystal grain boundary with an orientation difference of 15 ° or more is defined, and a crystal grain consisting of 2 pixels or more is the target of analysis.

Then, in the obtained KAM image, two lines parallel to the plate thickness direction and crossing the plate thickness are drawn at intervals of 50 μm, and the KAM values in the crystal grains on each line are measured and averaged, and averaged. The KAM value E is _{0 °} , the average KAM value is E _{45 °} , and the average KAM value is E _{90 °} . The standard deviation of each average KAM value is calculated for each crystal grain on each line.

As described above, the copper alloy plate material in which the average crystal grain size A and its anisotropy B are controlled within predetermined ranges has good burring workability. Further, the copper alloy plate material in which the average KAM value E and its anisotropy F are controlled within predetermined ranges has good burring workability. Further, the copper alloy plate material in which the average crystal grain size A and its anisotropy B are controlled within the predetermined ranges and the average KAM value E and the anisotropy F are controlled within the predetermined ranges can be further improved in burring. Has sex.

Further, regarding the thickness of the copper alloy plate material, the upper limit value is preferably 0.50 mm, and the lower limit value is preferably 0.05 mm. When the plate thickness of the copper alloy plate material is larger than 0.50 mm, deep wrinkles are likely to be formed on the outside and inside of the base portion of the hole flange formed after the burring process, and cracks may be generated and propagated. Further, if the plate thickness of the copper alloy plate material is smaller than 0.05 mm, the rigidity of the copper alloy plate material decreases.

Next, a method for manufacturing the copper alloy plate material of the embodiment will be described. The method for producing the copper alloy plate material of the embodiment is as follows: casting step (step 1), homogenizing heat treatment step (step 2), hot rolling step (step 3), surface milling step (step 4), and cooling on the copper alloy material. The inter-rolling step (step 5), the intermediate heat treatment step (step 6), the finishing cold rolling step (step 7), and the tempering annealing step (step 8) are performed in this order, and the rolled material in the cold rolling step (step 5) is performed. The ratio (T6 / R5) of the maximum temperature T6 (° C.) of the heat-treated material in the intermediate heat treatment step (step 6) to the processing rate R5 (%) of is 8.0 or more and 20.0 or less, and the maximum temperature T6 is 400 ° C. At 650 ° C or lower, in a pair of work rolls provided in each pass of the finish cold rolling step (step 7), the roll gap shape ratio represented by the following formula (3) is adjusted with respect to the average value M7 of each pass. The ratio (T8 / M7) of the maximum temperature T8 (° C.) of the annealed material in the quality rolling step (step 8) is 10.0 or more and 100.0 or less, and the maximum temperature T8 is 250 ° C. or more and 700 ° C. or less.

M7 = 3 × {r (h ₁ −h ₂ )} ^1/2 / {n (h ₁ + 2h ₂ )} ... Equation (3)

In the above formula (3), r is the radius (mm) of the work roll, and h ₁ is the thickness (mm) of the rolled material before each pass of the finish cold rolling step (step 7). h ₂ is the thickness (mm) of the rolled material after each pass of the finish cold rolling step (step 7), and n is the total number of passes of the finish cold rolling step (step 7). ..

In the casting step (step 1), a copper alloy ingot having a predetermined shape is obtained by melting the alloy component and casting. For example, melting is performed in the atmosphere using a high frequency melting furnace. The type of alloy component, casting conditions, etc. are set as appropriate.

In the homogenization heat treatment step (step 2), the copper alloy ingot obtained in the casting step (step 1) is subjected to homogenization heat treatment under predetermined heating conditions (for example, 1000 ° C. or lower for 1 hour). The homogenizing heat treatment step (step 2) is performed, for example, in the atmosphere.

In the hot rolling step (step 3), cooling is performed immediately after the plate thickness is set to a predetermined value (for example, 15 mm).

In the face-cutting step (step 4), a face-cutting of a predetermined thickness (for example, 2.5 mm or more and 5.0 mm or less) is performed from the surface of the hot-rolled plate to remove the oxide film.

In the cold rolling step (step 5), cold rolling is performed so that the processing rate R5 of the rolled material is 25% or more and 70% or less.

In the intermediate heat treatment step (step 6), the heat treatment is performed with the maximum temperature T6 of the heat treatment material being 400 ° C. or higher and 650 ° C. or lower, and the holding time at the maximum temperature T6 being 1 minute or more and 10 hours or less. The intermediate heat treatment step (step 6) is performed in a non-oxidizing atmosphere such as argon. The lower limit of the maximum temperature T6 of the heat-treated material in the intermediate heat treatment step (step 6) is 400 ° C. When the maximum temperature T6 of the heat-treated material in the intermediate heat treatment step (step 6) is 400 ° C. or higher, the recovery of the heat-treated material improves the burring workability, and Cr particles are precipitated to increase the strength and conductivity. .. On the other hand, when the maximum temperature T6 is higher than 650 ° C., softening of the material proceeds.

The ratio (T6 / R5) of the maximum temperature T6 (° C.) of the heat-treated material in the intermediate heat treatment step (step 6) to the processing rate R5 (%) of the rolled material in the cold rolling process (step 5) is 8.0 or more. It is 20.0 or less. When the ratio (T6 / R5) is within the above range, strength and conductivity can be exhibited in a well-balanced manner.

The higher the processing ratio R5, the lower the driving force for the Cr-containing compound to be generated in the copper alloy plate as the second phase, and thereby the strength of the copper alloy plate due to the formation of the second phase. The maximum temperature T6 in the intermediate heat treatment step (step 6) at which the amount of increase peaks is lowered. Further, the higher the maximum temperature T6 in the intermediate heat treatment step (step 6), the more the formation of the second phase is promoted, and the conductivity of the copper alloy plate material is improved. On the other hand, if the maximum temperature T6 is too high, the crystal grains become coarse after recrystallization, and the burring processability deteriorates. Therefore, the balance between the processing rate R5 and the maximum temperature T6 is important, and the control of the maximum temperature T6 itself is also important.

In the finish cold rolling step (step 7), cold rolling is performed by a pair of work rolls provided in each pass. The maximum temperature of the rolled material during finish cold rolling is, for example, 75 ° C. or higher and 150 ° C. or lower. The finish cold rolling step (step 7) is performed for processing to a predetermined plate thickness, improving the strength of the copper alloy plate material, and controlling the crystal state such as the crystal grain size and the KAM value.

The average value M7 of each pass of the roll gap shape ratio represented by the formula (3) in the finish cold rolling step (step 7) will be described with reference to FIG.

M7 = 3 × {r (h ₁ −h ₂ )} ^1/2 / {n (h ₁ + 2h ₂ )} ... Equation (3)

As shown in FIG. 2, in the finish cold rolling step (step 7), a pair of work rolls 20 are provided in each pass. A pair of work rolls 20 having a radius r rotate in opposite directions. When the rolled material moves in the rolling direction, _{the rolled material 21 before each pass having a thickness h 1} is cooled and rolled by the rotation of the work roll 20 to the rolled material 22 after each pass having _{a thickness h 2.} It will be processed.

In the tempering annealing step (step 8), heat treatment is performed with the maximum temperature T8 of the annealed material being 250 ° C. or higher and 700 ° C. or lower, and the holding time at the maximum temperature T8 being 10 seconds or more and 1 hour or less. The temper annealing step (step 8) under such heat treatment conditions is performed in order to restore the elongation of the copper alloy plate material and to reduce the anisotropy of the mechanical properties including the elongation. The temper annealing step (step 8) is performed in a non-oxidizing atmosphere such as argon.

Regarding the ratio (T8 / M7) of the maximum temperature T8 (° C.) of the annealed material in the temper annealing step (step 8) to the average value M7 of the roll gap shape ratio in each pass in the finish cold rolling step (step 7). The lower limit is 10.0 and the upper limit is 100.0. When the ratio (T8 / M7) is within the above range, the anisotropy of the KAM value and the KAM value is controlled, and the burring workability is improved. Further, by controlling the ratio (T6 / R5) and the ratio (T8 / M7), the crystal grain size, its anisotropy, and the standard deviation can be controlled.

Generally, in a rolled material, the deformed structure is different due to the difference in metal flow (forging line) between the vicinity of the surface layer which is close to the work roll and the inside which is far from the work roll. The average value M7 of the roll gap shape ratio can be appropriately adjusted to control the crystal grain size and KAM value after heat treatment in the temper annealing step (step 8), and their anisotropy and standard deviation.

When the average value M7 of the roll gap shape ratio in the finish cold rolling step (step 7) is large, that is, when the rolling reduction amount per pass is large or the radius of the work roll is large, the entire surface to the inside of the rolled material is large. The copper alloy plate material that has been strain-removed by the tempering annealing step (step 8) tends to have a uniform deformed structure. Therefore, the holding time at the maximum temperature T8 and the maximum temperature T8 of the temper annealing step (step 8) is determined from the balance between strain removal and softening. For example, if the ratio (T8 / M7) is larger than 100.0, the inside of the strain-removed copper alloy plate material is softened.

Further, in the method for producing a copper alloy plate material of the above embodiment, a cold rolling step (step A1) and an intermediate heat treatment step (step A2) are performed between the face cutting step (step 4) and the cold rolling step (step 5). ) Is further preferable. Specifically, the cold rolling step (step A1) is performed after the face cutting step (step 4), and the intermediate heat treatment step (step A2) is performed after the cold rolling step (step A1), and cold rolling is performed. The step (step 5) is performed after the intermediate heat treatment step (step A2).

The intermediate heat treatment step (step A2) is a step performed to easily adjust the processing rate of the rolled material in the cold rolling step (step 5). For example, the maximum temperature of the heat treatment material is set to 300 ° C. or higher and 1000 ° C. or lower. The heat treatment is performed so that the holding time at the maximum temperature is 10 seconds or more and 3 hours or less. Further, in the cold rolling step (process A1), the processing rate of the rolled material is appropriately adjusted so that the rolled material has a predetermined processing rate in the cold rolling step (step 5). When the intermediate heat treatment step (step A2) is not performed, the cold rolling step (step A1) is not performed and can be concentrated in the cold rolling step (step 5). The cold rolling step (step A1) and the intermediate heat treatment step (step A2) can be omitted depending on the plate thickness at the time of the process and the plate thickness of the copper alloy plate material to be manufactured.

Next, the members for electric / electronic parts of the embodiment will be described. The member for electric / electronic parts of the embodiment has a burring hole in the copper alloy plate material of the above embodiment.

The burring holes formed by the burring process will be described with reference to FIGS. 3 to 4.

First, as shown in FIG. 3, by performing punching punching the copper alloy sheet 32 by punching a punch 31 towards the punching direction, opening the through hole 33 of diameter d ₀ of the copper alloy sheet 32. Subsequently, as shown in FIG. 4, a hole expansion punch 34 is inserted into the through hole 33 in the insertion direction, and a hole expansion process is performed in which the periphery of the through hole 33 is plastically deformed so as to expand the through hole 33. Therefore, it is possible to form a convex burring hole 35 having a diameter d that protrudes in the insertion direction of the hole punch 34. In this way, it is possible to obtain the member 30 for electrical / electronic parts in which the burring hole 35 is formed in the copper alloy plate member 32.

Here, an example of burring processing in which punching processing and hole expansion processing are performed is shown, but burring processing is not particularly limited as long as a burring machined hole can be formed. For example, the burring process may be performed by performing only hole expansion processing on a copper alloy plate material having already formed through holes without performing punching processing.

Further, the hole expansion ratio λ represented by the following formula (4) of the burring machined hole is preferably 20% or more. When the hole expansion ratio λ is 20% or more, it is possible to sufficiently design the shape when the member for an electric / electronic component is used as a component of an electric / electronic device or the like.

λ = 100 × (dd ₀ ) / d ₀ ... Equation (4)

In the above formula (4), d ₀ is the diameter (mm) of the hole before the hole expansion process, and d is the diameter (mm) of the burring machined hole after the hole expansion process. That is, d ₀ is the diameter of the through hole formed by the punching process, and d is the diameter of the burring machined hole formed by expanding the through hole by the hole expanding process.

The above-mentioned members for electrical and electronic parts are required to have excellent strength and conductivity as well as high burring workability. Connector, lead frame, relay, switch, socket, shield case, shield can, liquid crystal reinforcing plate for electronic equipment. , LCD chassis, reinforcing plates for organic EL displays, camera modules, battery pack cases, connectors for automobiles, shield cases, shield cans, and other electrical and electronic devices.

According to the embodiment described above, a copper alloy plate material having a predetermined tensile strength and conductivity and being controlled so that the crystal grain size, KAM value, standard deviation and anisotropy are within a predetermined range is produced. can do. The copper alloy plate material thus obtained is superior in strength, conductivity, and burring workability as compared with the conventional copper alloy plate material in which the crystal grain size, KAM value, standard deviation, and heterogeneity are not controlled. There is. Therefore, the members for electric / electronic parts in which the burring holes are formed in the copper alloy plate material can be used for various electric / electronic devices that require a balance of strength and conductivity and high burring workability.

Although the embodiments have been described above, the present invention is not limited to the above-described embodiments, but includes all aspects included in the concept of the present invention and the scope of claims, and various modifications are made within the scope of the present invention. be able to.

Next, Examples and Comparative Examples will be described, but the present invention is not limited to these Examples.

(Examples 1 to 17 and Comparative Examples 1 to 11)
Each alloy component was melted in the air by a high-frequency melting furnace, and this was cast by a mold to obtain a copper alloy ingot having a thickness of 30 mm having the alloy composition shown in Table 1. Next, after homogenizing heat treatment at 1000 ° C. for 1 hour in the air, it was immediately hot-rolled to a thickness of 15 mm and water-cooled. Next, the oxide film was removed from the surface layer of the rolled plate by face cutting of 2.5 mm or more and 5.0 mm or less to make the thickness 5.0 mm or more and 10.0 mm or less. Next, cold rolling was performed so that the thickness was 1.25 mm or more and 2.50 mm or less, and intermediate heat treatment was performed at 300 ° C. or more and 1000 ° C. or less for 10 seconds. Next, as shown in Table 2, cold rolling (step 5) having a processing ratio of R5 and a thickness of 0.25 mm or more and 1.25 mm or less is performed, and the holding time at the maximum temperature T6 and the maximum temperature T6 in an argon atmosphere. Intermediate heat treatment (step 6) is performed for 1 minute or more and 360 minutes or less, and finish cold rolling (step 7) is performed with an average value M7 of each pass of the roll gap shape ratio. In an argon atmosphere, the maximum temperature T8 and the maximum temperature T8 The heat-treated annealing (step 8) was carried out in the above-mentioned holding time of 1 minute or more and 60 minutes or less. In this way, a copper alloy plate having the thickness shown in Table 2 was obtained. The copper alloy plate material shown in Table 1 contains Bi, Se, As, and Ag as unavoidable impurities, and the content of the unavoidable impurities is 0.03% by mass or less for each component, and the total amount of the components is 0.10. It was less than% by mass.

[Measurement and evaluation]
The copper alloy plates obtained in the above Examples and Comparative Examples were measured and evaluated as follows. The results are shown in Tables 3-5.

[1] Crystal grain size and KAM value The crystal grain size and KAM value are high-resolution scanning analytical electron microscopes (manufactured by Nippon Denshi Co., Ltd., JSM-) with respect to the copper alloy plates obtained in the above Examples and Comparative Examples. It was obtained from the crystal orientation analysis data calculated using analysis software (OIM Analysis, manufactured by TSL) from the crystal orientation data continuously measured using the EBSD detector attached to 7001FA).

As shown in FIG. 1, the measurement areas are a cross section S _{0 ° cut out in the 0 ° direction with respect to the rolling direction, a cross section S 45 °} cut out in the 45 ° direction with respect to the rolling direction, and 90 ° with respect to the rolling direction. _{The cross section S 90 °} cut out in the direction was mirror-finished by electrolytic polishing. The measurement was performed with a step size of 0.1 μm in a field of view having a total plate thickness of 150 μm in width. Then, the orientation difference of 15 ° or more was set as the crystal grain boundary, and the crystal grain consisting of 2 pixels or more was set as the analysis target.

Regarding the crystal grain size, in the obtained IPF image, two lines parallel to the plate thickness direction and crossing the plate thickness are drawn at intervals of 50 μm, and the crystal grain size is measured and averaged by a cutting method to obtain an average crystal. The particle size A _{0 °} , the average crystal particle size A _{45 °} , and the average crystal particle size A _{90 °} were calculated, respectively. Further, in the obtained IPF image, two vertical lines having a length of 150 μm with respect to the plate thickness direction are drawn at intervals of 25 μm, and the crystal grain size is measured and averaged by a cutting method to obtain an average crystal grain size D. _{0 °} was calculated. The standard deviation of each average crystal grain size was calculated for each crystal grain on each line. Then, the average of the standard deviations of these average crystal grain sizes was calculated.

Regarding the KAM value, in the obtained KAM image, two lines parallel to the plate thickness direction and crossing the plate thickness are drawn at intervals of 50 μm, and the KAM value in the crystal grains on each line is measured and averaged. , The average KAM value E _{0 °} , the average KAM value E _{45 °} , and the average KAM value E _{90 °} were calculated, respectively. The standard deviation of each average KAM value was calculated for each crystal grain on each line. Then, the average of the standard deviations of these average KAM values was calculated.

[2] Tensile strength (TS)
Tensile tests were performed on the copper alloy plates obtained in the above Examples and Comparative Examples using three JIS 13B test pieces (n = 3) based on JIS Z 2241: 2011, and three measured values. The tensile strength (TS) was calculated by averaging. The tensile strength is the tensile strength in the direction parallel to rolling.

[3] Conductivity (EC)
The specific resistance of the copper alloy plate materials obtained in the above Examples and Comparative Examples was measured by the 4-terminal method in a constant temperature bath kept at 20 ° C (± 0.5 ° C) with a distance between terminals of 100 mm. By doing so, the resistivity (EC) was calculated.

[4] Burling workability With respect to the copper alloy plate materials obtained in the above Examples and Comparative Examples, the clearance was set to 1/2 the thickness of the copper alloy plate material, and by press punching, _{a circular penetration having a diameter d 0} of 10 mm was obtained. After making a hole, a hole expansion process was performed to expand the through hole with a punch having a tip angle of 60 ° and a diameter of 10 to 20 mm. Then, the hole expansion rate when cracks occur was defined as the hole expansion rate λ. In addition, the burring workability was ranked as follows. The higher the hole expansion rate λ, the better the burring workability.

⊚: λ is 50% or more ○: λ is 20% or more and less than 50% ×: λ is less than 20%

As shown in Tables 1 to 5, in Examples 1 to 17, the Cr content, tensile strength, conductivity, crystal grain size, KAM value, and anisotropy were controlled within predetermined ranges, so that the strength was determined. Both conductivity and burring workability were good. In particular, in Examples 1 and 8, the processing ratio R5, the maximum temperature T6, the average value M7 of the roll gap shape ratio, the maximum temperature T8, the ratio (T6 / R5), and the ratio (T8 / M7) are adjusted within suitable ranges, respectively. By doing so, the crystal grain size, KAM value, and anisotropy are further improved, so that the burring workability is further improved.

On the other hand, in Comparative Example 1, the Cr content is low, the anisotropy of the average KAM value is large, the maximum temperature T6 is low, the ratio (T6 / R5) is large, the tensile strength is small, and the burring workability is poor. there were. In Comparative Example 2, the maximum temperature T6 was low and the tensile strength was small. In Comparative Example 3, the average crystal grain size, its anisotropy, and the average value of the standard deviation were large, the maximum temperature T6 was high, the tensile strength was small, and the burring workability was poor. In Comparative Example 4, the Cr content was high, coarse crystallized products containing Cr were generated during casting, and cracks were induced, so that the burring workability was poor. In Comparative Example 5, the anisotropy of the average KAM value was large, the conductivity was low, and the burring workability was poor. In Comparative Example 6, the average KAM value and its anisotropy were large, the maximum temperature T6 was low, the maximum temperature T8 was low, the ratio (T6 / R5) was small, and the burring workability was poor. In Comparative Example 7, the average value of the average crystal grain size and its standard deviation was large, the maximum temperature T8 was high, the ratio (T8 / M7) was large, the tensile strength was small, and the burring workability was poor. In Comparative Example 8, the ratio (T6 / R5) was small and the tensile strength was small. In Comparative Example 9, the ratio (T8 / M7) was large and the tensile strength was small. In Comparative Example 10, the anisotropy of the average KAM value was large, the ratio (T6 / R5) was large, the tensile strength was small, and the burring workability was poor. In Comparative Example 11, the anisotropy of the average crystal grain size and the average value of the standard deviation are large, the anisotropy of the average KAM value is large, the ratio (T6 / R5) is large, and the ratio (T8 / M7) is small. , The burring workability was poor.

10 Copper alloy plate 20 Work roll 21 Rolled material before pass 22 Rolled material after pass 30 Parts for electrical and electronic parts 31 Punch for punching 32 Copper alloy plate 33 Through hole 34 Punch for expanding hole 35 Burling hole

Claims (7)

It has an alloy composition containing 0.10% by mass or more and 0.80% by mass or less of Cr, and the balance is Cu and unavoidable impurities.
Tensile strength is 350MPa or more and 800MPa or less,
Conductivity is 55% IACS or more and 90% IACS or less,
To the rolling direction, 0 ° direction cutout section S _{0 °} thickness direction of the mean crystal grain size A _{0 °} in cross-section S ₄₅ average plate thickness direction at _° crystal grain size A ₄₅ cut out in the 45 ° direction _°, and 90 ° directions in the cross section _{S 90 °} thickness direction of the mean crystal grain size _{a 90 °} in cut are all 10.0μm or less and a ₀ standard deviation _°, and the standard deviation of _{a 45 °} A The average value of the standard deviation of _{90 ° is 2.0 μm or less,}
Represented by the following formula (1), wherein the average crystal grain size A ₀ anisotropically degree B _{0 °} of _°, the average crystal grain anisotropically size B _{45 °} of diameter A _{45 °,} and the average crystal grain size A _{90 °} anisotropic degree _{B 90 °} is of both Ri der 10.0% and
The average KAM value E _{0 °} in cross-section S _{0 °,} the average KAM value _{E 45 °} in the cross-section _{S 45 °,} and the average KAM value _{E 90 °} in the cross-section _{S 90 °} are both at 10.0 ° or less, And the average value of the standard deviation of _{E 0 °,} the standard deviation of E _{45 ° and} the standard deviation of E _{90 ° is 3.0 ° or less.}
Formula represented by (2), the average KAM value E ₀ anisotropic degree F _{0 °} of _°, the average KAM value anisotropic degree _{F 45 °} of _{E 45 °,} and the average KAM value _{E 90 °} of the different Anisotropy F _{90 °} is 10.0% or less in each case
Copper alloy sheet, characterized in der Rukoto.
B _m = 100 × ( _Am −C) / C ・ ・ ・ Equation (1)
F _m = 100 × (E _m −G) / G ・ ・ ・ Equation (2)
However, in the above formula (1), m is 0 °, 45 ° or 90 °, and C is the average value of _{A 0 °} , A _{45 °} and A _{90 ° ((A 0 °} + A _{45 °} + A _{90). °)} / 3) der is,
In the above equation (2), m is 0 °, 45 ° or 90 °, and G is the average value of _{E 0 °} , E _{45 °} and E _{90 ° ((E 0 °} + E _{45 °} + E _{90 °} )). / 3) Ru der. The cross-section S ₀ mean crystal grain size D _{0 °} in the rolling direction in _° is less than 15.0 .mu.m, the copper alloy sheet according to claim 1. The alloy composition further contains at least 0.05% by mass or more and 2.50% by mass or less of one or more elements selected from the group consisting of Mg, Ti, Co, Zr, Zn, Sn and Si. The copper alloy plate material according to claim 1 or 2. The copper alloy plate material according to any one of claims 1 to 3 , wherein the thickness is 0.05 mm or more and 0.50 mm or less. The method for producing a copper alloy plate according to any one of claims 1 to 4.
Casting process (process 1), homogenizing heat treatment process (process 2), hot rolling process (process 3), surface milling process (process 4), cold rolling process (process 5), intermediate heat treatment process on copper alloy material (Step 6), finish cold rolling step (step 7) and tempering annealing step (step 8) are performed in this order.
The ratio (T6 / R5) of the maximum temperature T6 (° C.) of the heat-treated material in the intermediate heat treatment step (step 6) to the processing rate R5 (%) of the rolled material in the cold rolling step (step 5) is 8. 0 or more and 20.0 or less,
The maximum temperature T6 is 400 ° C. or higher and 650 ° C. or lower.
The temper annealing step with respect to the average value M7 of the roll gap shape ratio represented by the following formula (3) in each pass of the pair of work rolls provided in each pass of the finish cold rolling step (step 7). The ratio (T8 / M7) of the maximum temperature T8 (° C.) of the annealed material in (Step 8) is 10.0 or more and 100.0 or less.
A method for producing a copper alloy plate material, wherein the maximum temperature T8 is 250 ° C. or higher and 700 ° C. or lower.
M7 = 3 × {r (h ₁ −h ₂ )} ^1/2 / {n (h ₁ + 2h ₂ )} ... Equation (3)
However, in the formula (3), r is the radius (mm) of the work roll, and h ₁ is the thickness (mm) of the rolled material before each pass in the finish cold rolling step (step 7). Yes, h ₂ is the thickness (mm) of the rolled material after each pass of the finish cold rolling step (step 7), and n is the total number of passes of the finish cold rolling step (step 7). Is. A member for an electric / electronic component, wherein the copper alloy plate material according to any one of claims 1 to 4 has a burring hole. The member for electrical / electronic parts according to claim 6 , wherein the burring hole has a hole expansion ratio λ represented by the following formula (4) of 20% or more.
λ = 100 × (dd ₀ ) / d ₀ ... Equation (4)
However, in the above formula (4), d ₀ is the diameter (mm) of the hole before the hole expansion process, and d is the diameter (mm) of the burring machined hole after the hole expansion process.

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