JP6611222B2 - Copper alloy plate for electric and electronic parts having high strength, high conductivity and excellent stress relaxation characteristics, and method for producing the same - Google Patents

Description

The present invention relates to a high-strength and high-conductivity copper alloy plate having excellent stress relaxation resistance and a method for producing the same , and more specifically to a Cu—Cr alloy plate for electrical and electronic components and a method for producing the same .

  Copper alloys used for terminals of electrical components mounted on automobiles are required to have characteristics such as electrical conductivity, strength, stress relaxation resistance, bending workability, and heat resistance peelability of Sn plating. Cu-Ni-Si alloys are often used as small fitting terminals with a good balance and a low energization current. On the other hand, Cu-Fe-P-based alloys are used for bus bars and power-based terminals with high energization current. In hybrid cars and electric cars that have been increasing in recent years, in addition to a voltage of 200 to 600 V, a higher current flows than before, and the terminals are heated. For this reason, in order to maintain a favorable contact, the stress relaxation resistance higher than before is required. Specifically, heat resistance at the 200 ° C. level is required.

The Cu—Ni—Si based alloy has low stress relaxation resistance at 200 ° C., and the Cu—Fe—P based alloy has high electrical conductivity but low stress relaxation resistance. For this reason, there is a demand for a copper alloy having a high electrical conductivity and a high stress relaxation property that has a higher stress relaxation property than before.
In response to such a requirement, Patent Document 1 includes Cr: 0.1 to 0.4 mass%, Ti: 0.005 to 0.15 mass%, and Si: 0.01 to 0.10 mass%. Cu-Cr alloys have been proposed. This copper alloy has the characteristics that the electrical conductivity is 65% IACS or more, the 0.2% proof stress is 460 MPa, and the stress relaxation rate after heating at 150 ° C. for 1000 hours is 20% or less.
Patent Document 2 discloses a Cu-Cr alloy containing Cr: 0.10 to 0.50 mass%, Ti: 0.010 to 0.30 mass%, and Si: 0.01 to 0.10 mass%. Has been proposed. This copper alloy has an electrical conductivity of 70% IACS or higher, a 0.2% proof stress of 450 MPa or higher, and excellent bending workability.

JP 2012-214882 A JP2013-204060A

The use of the Cu—Cr alloy is being studied as a material for a fitting terminal or the like that requires a higher conductivity than the Cu—Ni—Si alloy. On the other hand, stress relaxation resistance is important to ensure contact reliability of terminals exposed to high-temperature environments such as in the vicinity of an automobile engine room.
The Cu-Cr alloy described in Patent Document 1 is said to have high strength, high electrical conductivity, and excellent stress relaxation resistance, but in recent years, excellent stress relaxation resistance is required in higher temperature environments. ing. In addition, regarding the stress relaxation resistance, not only the stress relaxation rate when holding at a constant temperature for a predetermined time, but also the change in stress relaxation rate with the passage of time (stress relaxation rate and H after holding at a constant temperature for ₁ hour). ₂ (<H ₁ ) Difference in stress relaxation rate after holding for an hour) is also an important characteristic. If the change in the stress relaxation rate with the passage of time is small, it is easy to predict the amount of stress relaxation after the vehicle is mounted, and the degree of freedom in terminal design can be improved.

  The present invention improves the stress relaxation resistance of the Cu-Cr alloy plate, more specifically, reduces the stress relaxation rate after holding at high temperature for a long time, and changes the stress relaxation rate over time. The purpose is to make it smaller.

As described in Patent Documents 1 and 2, generally, Cu-Cr alloys are generally homogenized, hot rolled (quenched after hot rolling), multiple cold rolling and cold rolling. Manufactured in the process of intermediate annealing between processes and aging treatment.
On the other hand, the solid solution amount of Cr with respect to Cu is not so large as 0.65 ± 0.1% by mass at 1080 ° C. near the melting point of Cu, but is 0.37% by mass at 1000 ° C. and 0.15% by mass at 800 ° C. It is said to be 0.05% at 500 ° C. and less than 0.03% by mass at 400 ° C., and rapidly decreases as the temperature decreases. Further, when an element that forms a compound with Cr or an element that narrows the solid solubility limit of Cr is added to Cu, the solid solution amount of Cr with respect to Cu is further reduced. For this reason, under the conventional quenching conditions after hot rolling, Cr-containing precipitates that are second phase particles are unintentionally formed. According to the knowledge of the inventors, this Cr-containing precipitate is increased in size in the heat treatment process after hot rolling, which causes the stress relaxation resistance of the copper alloy to deteriorate.

  Based on this knowledge, in the present invention, a solution treatment is performed between the cold rolling processes, and the Cr-containing precipitates precipitated after the hot rolling are re-dissolved. A copper alloy sheet having stress relaxation characteristics could be obtained. Instead of performing this solution treatment, when the quenching temperature (cooling start temperature) after hot rolling is set to a higher temperature than before to prevent the precipitation of Cr-containing precipitates, it is also compared with the conventional case. Thus, a copper alloy sheet having remarkably excellent stress relaxation resistance could be obtained.

The copper alloy (Cu—Cr alloy) plate for electrical and electronic parts according to the present invention is Cr: 0.15 to 0.60 mass%, Si: 0.01 to 0.20 mass%, and Ti: 0.01. ~ 0.30 mass% and Zr: 0.01 to 0.20 mass% of one or two, the balance is made of Cu and unavoidable impurities , 0.2% in the direction parallel to and perpendicular to the rolling direction Both the proof stress are 500 MPa or more, the electrical conductivity is 65% IACS or more, the stress relaxation rate after heating at 200 ° C. for 100 hours is R _100, and the stress relaxation rate after heating at 200 ° C. for 1000 hours is R ₁₀₀₀ . The increase in stress relaxation rate (R ₁₀₀₀ -R ₁₀₀ ) is 7% or less, and R ₁₀₀₀ is 25% or less. This copper alloy plate can contain 1.0% by mass or less of one or more of Ag, Fe, Ni, Sn, Mg, Zn, Co, and Mn as required. In the present invention, the plate includes a strip.

  The copper alloy sheet according to the present invention has characteristics such as strength, electrical conductivity, bending workability and the like similar to those of conventional materials, and remarkably excellent stress relaxation resistance. When the copper alloy plate according to the present invention is used for, for example, a fitting type terminal or the like, contact reliability of the terminal particularly in a high temperature environment such as the vicinity of an automobile engine room or a high current part can be ensured.

Test No. of Example It is a microscope picture of the section of No. 2 copper alloy board.

Hereinafter, the copper alloy (Cu—Cr alloy) plate for electrical and electronic parts according to the present invention will be described more specifically.
[Composition of copper alloy]
(Cr: 0.15-0.60 mass%)
Cr forms a compound such as Cr—Si, Cr—Ti, Cr—Si—Ti alone or together with Si and Ti, and improves the strength of the copper alloy by precipitation hardening. By this precipitation, the solid solution amount of Cr, Si and Ti in the Cu matrix is decreased, and the conductivity of the copper alloy is increased. If the Cr content is less than 0.15% by mass, the increase in strength due to precipitation is not sufficient. On the other hand, if the Cr content exceeds 0.60 mass%, the precipitates become coarse, and the stress relaxation resistance and bending workability deteriorate. Therefore, the Cr content is in the range of 0.15 to 0.60 mass%. The lower limit of the Cr content is preferably 0.20% by mass, more preferably 0.25% by mass, and the upper limit is preferably 0.50% by mass, more preferably 0.40% by mass.

(Si: 0.01-0.20 mass%)
Si forms Cr—Si and Cr—Si—Ti compounds together with Cr and Ti, and increases the strength of the copper alloy by precipitation hardening. By this precipitation, the solid solution amount of Cr, Si and Ti in the Cu matrix is reduced, and the conductivity is increased. When the Si content is less than 0.01% by mass, the strength is not sufficiently improved by the Cr—Si precipitate or the Cr—Si—Ti precipitate. On the other hand, when the Si content exceeds 0.20 mass%, the solid solution amount of Si in the Cu matrix increases and the conductivity decreases. In addition, Cr—Si precipitates are coarsened, and bending workability and stress relaxation resistance are reduced. Therefore, the Si content is in the range of 0.01 to 0.20 mass%. The lower limit of the Si content is preferably 0.015% by mass, more preferably 0.02% by mass, and the upper limit is preferably 0.15% by mass, more preferably 0.10% by mass.

(Ti: 0.01-0.30 mass%)
Ti has a function of improving the heat resistance and stress relaxation resistance of the copper alloy by dissolving in the Cu base material. Ti forms precipitates with Cr and Si, and improves the strength of the copper alloy by precipitation hardening. By this precipitation, the solid solution amount of Cr, Si and Ti in the Cu matrix is decreased, and the conductivity of the copper alloy is increased. When the Ti content is less than 0.01% by mass, the heat resistance of the copper alloy is low, and it is difficult to obtain high strength by softening in the annealing process. Further, the stress relaxation resistance of the copper alloy cannot be improved. On the other hand, when the Ti content exceeds 0.30 mass%, the solid solution amount of Ti in the Cu matrix increases, leading to a decrease in conductivity. Accordingly, the Ti content is in the range of 0.01 to 0.30 mass%. The lower limit of the Ti content is preferably 0.015% by mass, more preferably 0.03% by mass, and the upper limit is preferably 0.20% by mass, more preferably 0.15% by mass.

(Zr: 0.01-0.20 mass%)
Zr has the effect of suppressing recovery or recrystallization due to processing heat in the course of thermomechanical processing, accumulating strain in the base material, and improving the strength of the copper alloy. It can be included. If the content of Zr is less than 0.01% by mass, the effect of accumulating strain cannot be obtained sufficiently. On the other hand, when the content of Zr exceeds 0.20% by mass, a coarse compound is formed, and the stress relaxation resistance and bending workability of the copper alloy are lowered. Therefore, the Zr content is in the range of 0.01 to 0.20 mass%. The lower limit of the Zr content is preferably 0.015% by mass, more preferably 0.03% by mass, and the upper limit is preferably 0.17% by mass, more preferably 0.15% by mass.

(Subcomponent: 1.0% by mass or less)
Subcomponents (Ag, Fe, Ni, Sn, Mg, Zn, Co, Mn) can be contained in one or more of a total of 1.0% by mass or less in the copper alloy as required. .
Ag is dissolved in the Cu base material and has the effect of improving the heat resistance and stress relaxation resistance of the copper alloy. Moreover, there exists an effect which forms sulfur and a compound in molten metal and reduces a sulfur containing inclusion. However, when the Ag content increases, the amount of solid solution in the Cu matrix increases and the conductivity decreases. Therefore, the content of Ag is set to 0.01 to 0.5% by mass. The lower limit of the Ag content is preferably 0.03% by mass, more preferably 0.05% by mass, and the upper limit is preferably 0.4% by mass, more preferably 0.3% by mass.

Fe and Ni form a compound with Cr, Ti, and Si, thereby reducing the solid solution amount of Cr, Ti, and Si in the Cu matrix and improving the conductivity. On the other hand, Fe and Ni decrease Ti in the Cu matrix and reduce the stress relaxation resistance of the copper alloy. Accordingly, the Fe and Ni contents are each 0.01 to 0.3% by mass, the lower limit is preferably 0.03% by mass, more preferably 0.05% by mass, and the upper limit is preferably 0.2% by mass. %, More preferably 0.1% by mass.
Sn and Mg improve work hardening characteristics by cold rolling, and are effective in increasing the strength of the copper alloy and improving stress relaxation characteristics. Zn has an effect of improving the heat-resistant peelability of Sn plating or solder used for joining electronic components. However, when the content of Sn, Mg, Zn increases, the solid solution amount of these elements in the Cu matrix increases and the conductivity decreases. Accordingly, the Sn content is 0.001 to 0.7 mass%, the Mg content is 0.001 to 0.3 mass%, and the Zn content is 0.001 to 1.0 mass%. . The lower limit of the Sn content is preferably 0.01% by mass, more preferably 0.1% by mass, and the upper limit is 0.6% by mass, more preferably 0.5% by mass. The lower limit of the Mg content is preferably 0.005% by mass, more preferably 0.01% by mass, and the upper limit is preferably 0.2% by mass, more preferably 0.15% by mass. The lower limit of the Zn content is preferably 0.01% by mass, more preferably 0.1% by mass, and the upper limit is preferably 0.8% by mass, more preferably 0.6% by mass.

Co and Mn form a compound with Ti and Si, reduce the solid solution amount of Ti and Si in the Cu matrix, and lower the electrical conductivity. On the other hand, Co and Mn reduce Ti in the Cu matrix and reduce the stress relaxation resistance of the copper alloy. Accordingly, the contents of Co and Mn are each 0.01 to 0.2% by mass, the lower limit is preferably 0.03% by mass, more preferably 0.05% by mass, and the upper limit is preferably 0.15% by mass. More preferably, the content is 0.1% by mass.
Further, the above-mentioned subcomponents have a small solid solution amount with respect to copper, and if they are contained in a total amount exceeding 1.0 mass%, they segregate at the grain boundaries or form crystallized products, resulting in strength characteristics and bending work. Deteriorate the sex. Accordingly, when one or more of Ag, Fe, Ni, Sn, Mg, Zn, Co, and Mn is added to the copper alloy according to the present invention, the total amount is 1.0% by mass or less.

(Inevitable impurities)
The copper alloy (Cu—Cr alloy) according to the present invention may contain one or more of Al, As, Sb, B, Pb, V, Mo, Hf, Ta, Bi, and In as inevitable impurities. In Cu—Cr alloys, these unavoidable impurities are usually in the range of 0.1% by mass or less in total unless otherwise added (that is, as unavoidable impurities). The problem does not occur. However, these elements have a remarkably small amount of solid solution with respect to copper, and when the total content exceeds 0.1% by mass, they segregate at the grain boundaries or form crystallized products, resulting in stress relaxation resistance and bending work. Deteriorate the sex. Therefore, the content of these inevitable impurities is preferably 0.1% by mass or less in total.

[Method for producing copper alloy sheet]
After a copper alloy material having a predetermined composition is melted and cast to produce an ingot, the ingot is homogenized, followed by hot rolling (quenching after hot rolling) and cold rolling. The solution treatment is performed during the cold rolling process, and after the cold rolling, the aging precipitation treatment is performed. In the quenching after hot rolling, when the quenching temperature (cooling start temperature) is set higher than before, the solution treatment can be omitted. Hereinafter, each step will be described more specifically.

The melting and casting of the copper alloy can be performed by ordinary methods. For example, after a copper alloy adjusted to a predetermined composition is melted in an electric furnace, a copper alloy ingot is cast.
The ingot is homogenized at 800 to 1000 ° C. for 0.5 hour or longer, and then hot rolled at a processing rate of 60% or more. Since the solid solution amount of Cr with respect to Cu rapidly decreases as the temperature decreases as described above, in the Cu—Cr series copper alloy containing 0.15% by mass or more of Cr as in the present invention, the hot rolling end temperature If it is low, Cr precipitates during hot rolling. The lower the hot rolling finish temperature, the easier it is for Cr to precipitate and the precipitated Cr tends to grow. For this reason, hot rolling is completed at 700 ° C. or higher, and then quenched and quenched. The quenching is preferably water cooling. When this quenching temperature (cooling start temperature) is lower than 700 ° C., coarse Cr-containing precipitates are formed, which tend to remain without being completely re-dissolved in the solution treatment after hot rolling. The stress relaxation resistance and bending workability of the alloy are reduced. In order to suppress the precipitation of Cr during hot rolling, it is preferable to increase the hot rolling start temperature and shorten the hot rolling time as much as possible.

  Subsequently, the hot-rolled material is cold-rolled to finish a copper alloy plate (or strip) having a desired thickness. The solution treatment performed in the middle of the cold rolling process is for re-solidifying Cr-containing precipitates formed during quenching after hot rolling, and is held at 750 to 850 ° C. for 15 to 120 seconds. After heating under conditions, quench. This solution treatment is accompanied by recrystallization. When the solution treatment temperature is lower than 750 ° C. or the holding time is shorter than 15 seconds, re-solution of the Cr-containing precipitate is insufficient, and the solution treatment temperature is higher than 850 ° C. or the holding time is longer than 120 seconds. And waste of energy. It is preferable to select the solution treatment temperature and time from the above range so that the crystal grain size after recrystallization is larger than the crystal grain size after hot rolling. The retention time of the solution treatment is preferably 15 to 60 seconds.

The purpose of aging precipitation treatment performed after cold rolling is to age-precise Cr alone and compounds such as Cr—Si and Cr—Si—Ti. The aging precipitation treatment is performed at 400 to 550 ° C. for 2 hours or more. For this aging treatment, it is appropriate to select a temperature lower than the recrystallization temperature, having a hardness as high as possible and an elongation of 10% or more.
A microstructure photograph of the cross section of the copper alloy sheet after the aging precipitation treatment is shown in FIG. 1 (Test No. 2 in the example). As shown in FIG. 1, not a recrystallized structure, but a fibrous processed structure in which the crystal grain structure greatly extends along the rolling direction is observed.

  When the hot rolling end temperature is 800 ° C. or higher and quenching is performed at a quenching temperature of 800 ° C. or higher, the precipitation of Cr-containing precipitates during hot rolling can be suppressed. Accordingly, in this case, quenching after hot rolling also serves as a solution treatment, and the solution treatment during the cold rolling can be omitted. The quenching temperature is preferably 850 ° C. or higher, and there is no particular upper limit for the quenching temperature. In addition, the lower limit (800 degreeC) of the quenching temperature in the case of not performing a solution treatment is set higher than the lower limit (750 degreeC) of the temperature of a solution treatment. This is because, in a hot-rolled material having a large thickness, even if the cooling at the time of quenching is water cooling, the cooling rate of the central portion of the thickness is reduced, and the temperature dependence of the solid solution amount is high (according to the temperature decrease) This is because precipitation of Cr, Zr, etc. easily proceeds.

[Characteristics of copper alloy sheet]
In the present invention, in the production of the Cu-Cr alloy plate having the above composition, as described above, a process including a solution treatment is applied during the cold rolling process, or quenching after hot rolling is performed at 800 ° C or higher. Apply the process performed at the quenching temperature. This makes it possible to produce a copper alloy sheet (cold rolled material) for electrical and electronic parts that has the same strength and electrical conductivity as the conventional material and has significantly better stress relaxation resistance than the conventional material. The specific stress relaxation characteristics of the copper alloy plate for electrical and electronic parts according to the present invention are as follows: R ₁₀₀ is the stress relaxation rate after heating at 200 ° C. for 100 hours, and R is the stress relaxation rate after heating at 200 ° C. for 1000 hours. _{When 1000} , the increase in stress relaxation rate (R ₁₀₀₀ −R ₁₀₀ ) is 7% or less, and R ₁₀₀₀ is 25% or less.

Copper alloys having various alloy compositions (alloy Nos. 1 to 20) shown in Table 1 were melted and then cast into a book mold to obtain an ingot having a thickness of 70 mm.
The ingot was soaked at 950 ° C. for 1 hour, then hot rolled to a plate thickness of 12 mm, and quenched from 700 ° C. Next, both surfaces of the copper alloy plate after quenching were polished to a thickness of about 1 mm to remove the oxide scale on the surface. Subsequently, a copper alloy plate having a thickness of 10 mm was formed into a thickness of 5 mm by cold rolling, held at 800 ° C. for 20 seconds, and then subjected to a solution treatment. The copper alloy sheet was recrystallized by this solution treatment. Thereafter, it was further formed into a thickness of 0.25 mm by cold rolling and subjected to an aging precipitation treatment at a temperature of 450 ° C. for 2 hours. 1 to 20 copper alloy plates (product plates) were obtained.
Test No. Samples (test pieces) were cut out from 1 to 20 copper alloy plates, and 0.2% proof stress measurement, conductivity measurement, and stress relaxation test were performed as follows. The results are shown in Table 1.

(Measurement of 0.2% proof stress)
Test No. JIS No. 5 test pieces defined in JISZ2201 were prepared from 1 to 20 copper alloy plates. As a JIS No. 5 test piece, a first test piece whose longitudinal direction is parallel to the rolling direction (LD: Longitudinal Direction) and a second test piece whose longitudinal direction is perpendicular to the rolling direction (TD: Transverse Direction) Created a type. Using these first and second test pieces, the tensile test specified in JISZ2241 was performed, and the tensile strength corresponding to the permanent elongation of 0.2% was measured as the 0.2% proof stress of each test piece. Those having a 0.2% proof stress of 500 MPa or more were evaluated as acceptable.

(Measurement of conductivity)
The conductivity was measured by measuring the volume resistivity by a four-terminal method using a double bridge in accordance with the nonferrous metal material conductivity measurement method specified in JISH0505. And the electrical conductivity was calculated | required by dividing the measured volume resistivity by the volume resistivity 1.7241 * 10 < ^-8 > (omega | ohm) * m of a universal standard annealed copper (International Annealed Copper Standard). Those having an electrical conductivity of 65% IACS or higher were evaluated as acceptable.

(Measurement of stress relaxation rate)
Test No. From each of the copper alloy plates 1 to 20, a strip-shaped test piece having a width of 10 mm and a length of 90 mm whose longitudinal direction is perpendicular to the rolling direction (TD) (five from each copper alloy plate of test Nos. 1 to 20) ) And the stress relaxation rate was measured by the cantilever method. First, one end of each test piece is fixed to a rigid test stand, and 10 mm of deflection is given to the test piece at a predetermined distance (span length) from the fixed end, corresponding to 80% of 0.2% proof stress at the fixed end. Loaded surface stress. The span length was calculated by a “stress relaxation test method by bending copper and copper alloy sheet strip” defined in the Japan Copper and Brass Association Technical Standard (JCBA-T309: 2004).
Subsequently, each test piece to which deflection was given as described above was put in an oven heated to 200 ° C., held for 100 hours, taken out, and the permanent strain δ when the deflection d (10 mm) was removed was measured. The stress relaxation rate RS = (δ / d) × 100 was calculated. Subsequently, one end of each test piece was fixed to the rigid body test stand again, the same span length was given to the position of the same span length from the fixed end, and it was again placed in an oven heated to 200 ° C. for 900 hours (total heating) The time was 1000 hours) and then taken out, and the stress relaxation rate was calculated in the same manner. Test No. For each of the copper alloy plates 1 to 20, a measurement test was performed using each of the five test pieces, and the average value of the obtained five stress relaxation rates was determined as the test number. It was set as the stress relaxation rate of each copper alloy plate of 1-20.
When the stress relaxation rate after holding at 200 ° C. for 100 hours is R ₁₀₀ and the stress relaxation rate after holding at 200 ° C. for 1000 hours (100 hours + 900 hours) is R ₁₀₀₀ , the increase in stress relaxation rate (R ₁₀₀₀ −R ₁₀₀ ) is 7% or less and _R1000 is 25% or less, it was evaluated as passing.

As shown in Table 1, test no. The copper alloy sheets 1 to 12 are manufactured by applying a process including a solution treatment in the middle of the cold rolling process in which the alloy composition satisfies the provisions of the present invention. Test No. Nos. 1 to 12 show an increase in stress relaxation rate (R ₁₀₀₀ -R ₁₀₀ ) of 7% or less until the holding time reaches 1000 hours after 100 hours have elapsed, and a stress relaxation rate (R ₁₀₀₀ ) after holding for 1000 hours. It is 25% or less, and the stress relaxation resistance is excellent. Moreover, electrical conductivity and 0.2% yield strength are high.

On the other hand, test no. Although the copper alloy plates of 13 to 20 are manufactured by applying a process including a solution treatment during the cold rolling process, the alloy composition does not satisfy the provisions of the present invention.
Test No. No. 13 has a low content of Cr and Ti, and therefore has a low 0.2% proof stress and inferior stress relaxation resistance. In Test No. 14, since the contents of Cr and Ti are excessive, the stress relaxation resistance is inferior and the electrical conductivity is low. Test No. 15 is inferior in stress relaxation resistance because the contents of Cr and Zr are excessive. In Test No. 16, since the contents of Cr, Ti and Zr are excessive, the stress relaxation resistance is inferior and the electrical conductivity is low. Test No. 17 has low electrical conductivity because of excessive Si content. Test No. 18 has a low electrical conductivity because the Fe and Ag contents are excessive. In Test No. 19, the Fe and Ag contents are excessive, and the total content of Al and Mn corresponding to inevitable impurities is excessive (greater than 0.1% by mass), so the conductivity is low. Test No. No. 20 is inferior in stress relaxation characteristics because the Co content is excessive.

Alloy No. shown in Table 1 A copper alloy having a composition of 1 to 4 was melted and then cast into a book mold to obtain an ingot having a thickness of 70 mm.
The ingot was soaked at 950 ° C. for 1 hour, then hot rolled to a plate thickness of 12 mm, and quenched from 700 ° C. Next, both surfaces of the copper alloy plate after quenching were polished to a thickness of about 1 mm to remove the oxide scale on the surface.
Subsequently, a copper alloy plate having a thickness of 10 mm was formed into a thickness of 0.25 mm by cold rolling without performing a solution treatment between processes, and subjected to an aging precipitation treatment at a temperature of 450 ° C. for 2 hours. No. 21 to 24 copper alloy plates (product plates) were obtained.

In addition, Alloy No. The copper alloy ingot No. 4 was soaked at 950 ° C. for 1 hour, hot-rolled to a sheet thickness of 12 mm, and quenched from 800 ° C. Next, both surfaces of the copper alloy plate after quenching were polished to a thickness of about 1 mm to remove the oxide scale on the surface.
Subsequently, a copper alloy plate having a thickness of 10 mm was formed into a thickness of 5 mm by cold rolling, held at 800 ° C. for 20 seconds, and then subjected to a solution treatment. Thereafter, it was further formed into a thickness of 0.25 mm by cold rolling and subjected to an aging precipitation treatment at a temperature of 450 ° C. for 2 hours. 25 copper alloy plates (product plates) were obtained.

Furthermore, alloy no. The copper alloy ingot No. 4 was soaked at 950 ° C. for 1 hour, hot-rolled to a sheet thickness of 12 mm, and quenched from 800 ° C. Next, both surfaces of the copper alloy plate after quenching were polished to a thickness of about 1 mm to remove the oxide scale on the surface.
Subsequently, a copper alloy plate having a thickness of 10 mm was formed into a thickness of 0.25 mm by cold rolling without performing a solution treatment between processes, and subjected to an aging precipitation treatment at a temperature of 450 ° C. for 2 hours. No. 26 copper alloy plates (product plates) were obtained.

  Test No. above. Samples (test pieces) were cut out from 21 to 26 copper alloy plates, and 0.2% proof stress measurement, conductivity measurement, and stress relaxation test were performed in the same manner as in [Example 1]. The results are shown in Table 2. For comparison, the test No. obtained in [Example 1] The results of 1-4 are shown in Table 2 together.

As shown in Table 2, test no. The copper alloy sheets 1 to 4 and 25 are manufactured by applying a process including a solution treatment in the middle of the cold rolling process in which the alloy composition satisfies the provisions of the present invention. In addition, Test No. The copper alloy plate of No. 26 is manufactured by applying a process in which the alloy composition satisfies the provisions of the present invention and quenching after hot rolling is performed at a quenching temperature of 800 ° C. or higher.
Test No. 1-4, 25, and 26, the increase in the stress relaxation rate (R ₁₀₀₀ −R ₁₀₀ ) after the holding time reaches 100 hours after 100 hours elapses is 7% or less, and the stress relaxation rate after holding for 1000 hours ( R ₁₀₀₀ ) is 25% or less, and the stress relaxation resistance is excellent. Moreover, electrical conductivity and 0.2% yield strength are high.

  On the other hand, test no. 21 to 24 are manufactured by applying a process in which the alloy composition satisfies the provisions of the present invention, but the quenching temperature after hot rolling is as low as 700 ° C., and a solution treatment is included in the process of cold rolling. Not. For this reason, no. 21 to 24 are inferior in stress relaxation resistance.

Claims (6)

Cr: 0.15 to 0.60% by mass, Si: 0.01 to 0.20% by mass, Ti: 0.01 to 0.30% by mass and Zr: 0.01 to 0.20% by mass One or two of the above, the balance is made of Cu and inevitable impurities , 0.2% proof stress both in the direction parallel to and perpendicular to the rolling direction is 500 MPa or more, the conductivity is 65% IACS or more, 200 ° C. When the stress relaxation rate after heating for 100 hours is R ₁₀₀ and the stress relaxation rate after heating at 200 ° C. for 1000 hours is R ₁₀₀₀ , the increase in stress relaxation rate (R ₁₀₀₀ −R ₁₀₀ ) is 7% or less. A copper alloy sheet for electrical and electronic parts having high strength, high electrical conductivity and excellent stress relaxation resistance , wherein R ₁₀₀₀ is 25% or less. Ag: 0.01-0.5 mass%, Fe: 0.01-0.3 mass%, Ni: 0.01-0.3 mass%, Sn: 0.001-0.7 mass%, Mg: One or two of 0.001 to 0.3 mass%, Zn: 0.001 to 1.0 mass%, Co: 0.01 to 0.2 mass%, Mn: 0.01 to 0.2 mass% The copper alloy plate for electrical and electronic parts having high strength, high electrical conductivity, and excellent stress relaxation resistance according to claim 1, comprising a total of 1.0% by mass or less of seeds or more. The total of at least one of the inevitable impurities Al, As, Sb, B, Pb, V, Mo, Hf, Ta, Bi and In is 0.1% by mass or less. Item 3. The copper alloy sheet for electrical and electronic parts according to item 1 or 2, which is excellent in stress relaxation resistance with high strength and high electrical conductivity . A method for producing a copper alloy plate for electrical and electronic parts according to any one of claims 1 to 3, wherein the copper alloy ingot is quenched after hot rolling , followed by cold rolling and aging treatment. The manufacturing method of the copper alloy plate for electrical and electronic components characterized by including the solution treatment which quenches after the said cold rolling heats on the conditions hold | maintained at 750-850 degreeC for 15 to 120 second in the middle of a process . The method for producing a copper alloy sheet for electric and electronic parts according to claim 4, wherein a quenching temperature of the quenching after the hot rolling is 800 ° C or higher. The copper alloy ingot quenched after hot rolling, followed have rows cold rolling and aging, there a method of manufacturing an electrical electronic component copper alloy sheet according to any of claims 1 to 3 A method for producing a copper alloy plate for electrical and electronic parts , wherein the quenching temperature of the quenching is 800 ° C. or higher.