JP4009244B2 - Aluminum alloy plate for caulking, its manufacturing method and aluminum alloy terminal - Google Patents

Description

  The present invention relates to an aluminum alloy plate for caulking, a method for producing the same, and an aluminum alloy terminal using the aluminum alloy plate for caulking, and particularly for caulking that can be used without stress relaxation even in a temperature range of 170 ° C. or lower. The present invention relates to an aluminum alloy plate, a manufacturing method thereof, and an aluminum alloy terminal.

  Aluminum alloys are light in weight, high in strength, excellent in heat and electrical conductivity, and corrosion resistance, and thus are used in a wide range of fields such as daily goods such as beverage cans and pans, engines and peripheral parts, and electric wires. On the other hand, for example, when the aluminum alloy is used for screwing after being processed into a bolt shape, the fastening strength tends to decrease due to stress relaxation when used for a long time in a temperature environment of about 120 to 160 ° C. It was never used in the temperature range. The same applies to the caulking process, and stress relaxation is remarkable in the temperature range of 120 to 160 ° C., so that the aluminum alloy was not used for parts having caulking portions.

  As described above, an aluminum alloy exhibits a remarkable creep or stress relaxation phenomenon under a temperature condition of about 120 to 160 ° C., so it is rarely used alone, and SUS or the like is used for bolting or threading. It is currently used only for applications that are used in combination with other metals and allow some deformation.

  On the other hand, copper alloys are used for electric wires and terminals because of their excellent conductivity, and are caulked in many parts, and stress relaxation is a general evaluation test (non-patent) Reference 1). The stress relaxation property of the copper alloy at a temperature of 120 to 160 ° C. is that when C2600 (70% Cu—Zn alloy) is kept at a temperature of 160 ° C. for 1000 hours, the residual stress is 20% or less (stress relaxation 80%). (See Non-Patent Document 2).

Edited by Yotaro Murakami, "Basics and Industrial Technology of Copper and Copper Alloys", 1st Edition, Japan Copper and Brass Association, May 25, 1988, p. 384 Edited by Yotaro Murakami, “Copper Products Data Book”, 1st Edition, Japan Copper and Brass Association, August 1, 1997, p. 187

  However, if a weight reduction is sought in a part where deformation is not permitted, the need to use an aluminum alloy alone arises. For this reason, there is a strong demand for the development of aluminum alloys with low creep or stress relaxation.

  The present invention has been made in view of such a problem, and can be bolted and caulked with a strong stress in the initial stage, and the strength is hardly lowered even when left in a temperature environment of 170 ° C. or lower for a long time. An object of the present invention is to provide an aluminum alloy plate with less stress relaxation in a temperature range of ° C. or lower, a method for producing the same, and an aluminum alloy terminal.

  The aluminum alloy plate for caulking according to the first invention of the present application contains Cu: 0.2 to 0.9 mass%, Mg: 0.6 to 1.4 mass%, and the balance is made of Al and inevitable impurities. Among the inevitable impurities, Si: 0.8 mass% or less, Fe: 0.6 mass% or less, Mn: 0.15 mass% or less, Cr: 0.3 mass% or less, Zn: 0.3 mass %, Ti: 0.1% by mass or less, Zr: 0.15% by mass or less, the plate thickness is greater than 1.0 mm and less than 3.0 mm, and the crystal grain size is 35 to It is 300 μm and has a conductivity of 50% IACS or less.

  It is preferable that the aluminum alloy plate has a stress relaxation rate of 50% or less after being subjected to 30% processing corresponding to caulking and further maintained at a temperature of 160 ° C. for 100 hours.

  The manufacturing method of the aluminum alloy plate for caulking according to the second invention of the present application contains Cu: 0.2 to 0.9 mass%, Mg: 0.6 to 1.4 mass%, the balance being Al and inevitable Consisting of impurities, among the inevitable impurities, Si: 0.8 mass% or less, Fe: 0.6 mass% or less, Mn: 0.15 mass% or less, Cr: 0.3 mass% or less, Zn: 0 .3% by mass or less, Ti: 0.1% by mass or less, Zr: 0.15% by mass or less, after hot rolling an aluminum alloy sheet, cold rolling at a processing rate of 7 to 60% Then, after holding for 1 hour or less at a temperature of 500 to 570 ° C. and then cooling at a rate of 1 ° C./second or more, the plate thickness is greater than 1.0 mm and less than 3.0 mm, and the crystal grain size Is 35 to 300 μm, and the conductivity is 50% IACS or more. Characterized by producing the aluminum alloy plate is.

  Moreover, in the said manufacturing process, cold rolling and intermediate annealing can also be performed between the said hot rolling and the cold rolling of a processing rate 7 thru | or 60%.

  In the aluminum alloy terminal according to the third invention of the present application, a Ni plating film having a thickness of 0.5 to 5.0 μm is formed on the surface of the aforementioned aluminum alloy plate for caulking, and further on the Ni plating film. A Sn plating film having a thickness of 1 to 10 μm is formed.

  In the present invention, since the Ni plating film and the Sn plating film are formed on the surface of the above-mentioned caulking aluminum alloy plate, a terminal having low contact resistance and excellent corrosion resistance is manufactured at the same cost as the conventional product. can do.

  This aluminum alloy terminal can be used, for example, as an automotive part.

  According to the present invention, in the aluminum alloy, by optimizing the contents of Cu and Mg, regulating the content of inevitable impurities, and further optimizing the production conditions, plate thickness, crystal grain size and conductivity, Even when the internal stress is relaxed under a use environment temperature of about 160 ° C. or less and used in a component having a caulking portion, an aluminum alloy plate having a predetermined strength and stress resistance relaxation can be obtained.

  The inventors of the present invention are inferior in stress relaxation properties, which is a problem inherent to aluminum alloys. The stress relaxation characteristics of aluminum alloys have been intensively studied by the stress relaxation test described above, and an aluminum alloy with less stress relaxation and its manufacturing conditions have been developed.

  First, the caulking aluminum alloy plate according to the first invention will be described in detail. In order to ensure the initial strength, the present inventors need to give strength (proof strength) by solid solution strengthening with Mg, and further give strength (cross-sectional area increase) by increasing the thickness of the used plate material. I found out that there is. Further, in order to reduce stress relaxation at 120 to 160 ° C., by suppressing the Si content and adding Cu, Mg solids due to precipitation of β ′ phase (Mg—Si), which is a coarse Mg-based precipitate, are added. It has also been found that it is necessary to prevent the amount of solution from decreasing and to further increase the crystal grain size, or to increase the moving distance of dislocations and holes by increasing the plate thickness.

  The essential conditions for obtaining the above-described state are Cu: 0.2 to 0.9% by mass, Mg: 0.6 to 1.4% by mass, and the balance is made of Al and inevitable impurities, and the above inevitable Among general impurities, Si: 0.8 mass% or less, Fe: 0.6 mass% or less, Mn: 0.15 mass% or less, Cr: 0.30 mass% or less, Zn: 0.3 mass% or less, In an aluminum alloy plate with Ti: 0.1% by mass or less and Zr: 0.15% by mass, the plate thickness is greater than 1.0 mm and less than 3.0 mm, the crystal grain size is 35 to 300 μm, and the electrical conductivity Is 50% IACS (International Annealed Copper Standard: conductivity when the conductivity of a pure copper annealed material is 100%) or less.

  Below, the reason for limitation in the aluminum alloy plate of this invention is demonstrated in detail.

Cu: 0.2 to 0.9% by mass
Cu is added to improve the strength, to suppress the precipitation of the β ′ phase, and to refine the precipitate. If the Cu content is less than 0.2% by mass, sufficient effects cannot be obtained. Moreover, when Cu content exceeds 0.9 mass%, since these effects are saturated and a coarse precipitate is formed, caulking workability is reduced. Therefore, the Cu content is 0.2 to 0.9 mass%.

Mg: 0.6 to 1.4% by mass
In order to strongly caulk in the initial stage, the material needs to have a certain degree of strength and elongation. In order to obtain these effects, it is necessary to contain 0.6 mass% or more of Mg. However, when the Mg content exceeds 1.4% by mass, the solid solubility limit is exceeded at a temperature range of 170 ° C. or lower, and even if it is deposited alone, vacancies are moved, which makes it easy to relieve stress. . Therefore, the Mg content is 0.6 to 1.4% by mass.

Inevitable impurities Si, which is an inevitable impurity element, becomes a coarse β 'phase structure in an over-aged state when held at 160 ° C for a long time, and it becomes easy to relax stress by generating vacancies. Restrict to mass% or less. It is desirable that Si is essentially not contained at all. However, in normal production, it is often contained in an amount of about 0.4 to 0.6% by mass. In this case, Cu is added to precipitate β ′ phase. And the movement of holes is suppressed. If the content of Fe exceeds 0.6% by mass, the crystal grains are likely to be refined, so that the crystal grains become less than 35 μm and fall outside the scope of the first invention of the present application. To regulate. Mn is restricted to 0.15% by mass or less because the stress relaxation property is lowered when the content exceeds 0.15% by mass. Since Cr is easy to refine crystal grains, the content is restricted to 0.3 mass% or less. When the content of Zn exceeds 0.3% by mass, the stress relaxation characteristics are lowered, so the content is restricted to 0.3% by mass or less. Ti contributes to refinement of the ingot structure, but if the content exceeds 0.1% by mass, the stress relaxation property is lowered, so the content is restricted to 0.1% by mass or less. If the content of Zr exceeds 0.15% by mass, the giant compound Al ₃ Zr is likely to be generated, and the caulking processability is deteriorated.

Plate thickness : If the plate thickness is greater than 1.0 mm and less than 3.0 mm and 1.0 mm or less, the strength during caulking is insufficient. On the other hand, if the plate thickness is 3.0 mm or more, the workability deteriorates and cracks are likely to occur. Therefore, in the present invention, the plate thickness is greater than 1.0 mm and less than 3.0 mm.

Crystal grain size: 35 to 300 μm
When the crystal grain size is less than 35 μm, the distance to the grain boundary, which is a vacancy annihilation site, is shortened and the area of the grain boundary is also increased, so that the stress relaxation characteristics are deteriorated. On the other hand, if the crystal grain size exceeds 300 μm, it causes skin cracking or cracking during caulking. Therefore, in the present invention, the crystal grain size is set to 35 to 300 μm.

Conductivity: 50% IACS or less The conductivity is an indicator of solid solution and precipitation of solute elements. When the electrical conductivity exceeds 50% IACS, for example, a compound containing Cu and Mg such as a stable phase S (CuMgAl ₂ ) and a stable phase β ′ (Mg ₂ Si) is coarsely precipitated, and strength and stress relaxation characteristics deteriorate. To do. Therefore, in the present invention, the conductivity is 50% IACS or less.

  Next, the manufacturing method of the aluminum alloy plate for caulking according to the second invention of the present application will be described in detail. As a manufacturing method of the aluminum alloy plate for caulking according to the present invention, first, Cu: 0.2 to 0.9 mass%, Mg: 0.6 to 1.4 mass% is contained, and the balance is Al and inevitable. Consisting of impurities, among the inevitable impurities, Si: 0.8 mass% or less, Fe: 0.6 mass% or less, Mn: 0.15 mass% or less, Cr: 0.3 mass% or less, Zn: 0 An ingot having a composition regulated to 3 mass% or less, Ti: 0.1 mass% or less, and Zr: 0.15 mass% or less is subjected to homogenization heat treatment and hot rolling according to a conventional method.

  Thereafter, final cold rolling is performed at a processing rate of 7 to 60%. If the processing rate of the final cold rolling is less than 7%, the recrystallized grains after the final heat treatment become too coarse, and if it exceeds 60%, the recrystallized grains become too fine. The plate thickness after this final cold rolling is greater than 1.0 mm and less than 3.0 mm. Further, as heat treatment, the temperature is maintained at 500 to 570 ° C. for 1 hour or less, and then cooled at a rate of 1 ° C./second or more. At that time, if the heating temperature is less than 500 ° C., the solid solution of the constituent elements is not sufficient, the desired strength at the time of caulking and the stress relaxation resistance required at the time of use cannot be obtained, and the heating temperature exceeds 570 ° C. There are concerns about burning. Further, if the heating time is longer than 1 hour, the crystal grain size becomes too coarse.

  In this manufacturing method, after homogenizing heat treatment and hot rolling, etc., cold rolling and intermediate annealing are performed, and then final cold rolling is performed at a processing rate of 7 to 60%, followed by heat treatment. it can. As intermediate annealing conditions at that time, it is desirable to carry out at a temperature of 340 to 400 ° C. for 30 minutes or more.

  Next, the aluminum alloy terminal according to the third invention will be described in detail. The aluminum alloy terminal of the present invention is a terminal that is attached to, for example, a wiring that connects a motor and an inverter, a battery and an inverter, and a battery and a relay box of an electric vehicle, a hybrid vehicle, and a conventional gasoline vehicle. Fig.1 (a) is a top view which shows the storage battery electric wire board terminal for motor vehicles, FIG.1 (b) is the side view. FIG. 2 (a) is a plan view showing a round plate terminal for automobiles, and FIG. 2 (b) is a side view thereof. Further, FIG. 3A is a perspective view showing an example of a state in which the aluminum alloy terminal of the present invention is attached to the wiring, and FIG. 3B is an enlarged view showing the connecting portion.

  In the aluminum alloy terminal of the present invention, a Ni plating film having a thickness of 0.5 to 5.0 μm is formed on the surface of the aluminum alloy plate for caulking, and the thickness is further formed on the Ni plating film. An Sn plating film of 1 to 10 μm is formed. As the shape, for example, an automobile storage battery wire plate terminal defined in JIS standard D5403 shown in FIGS. 1A and 1B, and an automobile round shape shown in FIGS. 2A and 2B. Although a board terminal etc. are mention | raise | lifted, it is not limited to these. And the aluminum alloy terminal of this invention is attached to the edge part of a cable, as shown to FIG. 3 (a) and (b), and is connected to metal wiring. Hereinafter, the reasons for limiting the thicknesses of the Ni plating film and the Sn plating film in the aluminum alloy terminal of the present invention will be described.

Ni plating film: 0.5 to 5.0 μm
The Ni plating film has an effect of improving the corrosion resistance. When the thickness of the Ni plating film is less than 0.5 μm, the effect of increasing the corrosion resistance is small, and sufficient corrosion resistance cannot be obtained. On the other hand, if the thickness of the Ni plating film exceeds 5.0 μm, the processing cost increases and cracking is likely to occur during bending. Therefore, the thickness of the Ni plating film is 0.5 to 5.0 μm.

Sn plating film: 1 to 10 μm
Since the Sn plating film is softer than the base aluminum alloy, it has the effect of reducing the contact resistance of the pressure contact portion. However, when the thickness of the Sn plating film is less than 1 μm, a sufficient effect cannot be obtained. On the other hand, when the thickness of the Sn plating film exceeds 10 μm, the processing cost increases. Therefore, the thickness of the Sn plating film is 1 to 10 μm.

  Hereinafter, the effect of the Example of this invention is demonstrated compared with the comparative example which remove | deviates from the scope of the present invention.

  First, as Example 1, an aluminum alloy having the composition shown in Table 1 below was used, and a plate thickness of 1.5 mm was obtained by the following manufacturing process. Aluminum alloy plates 1 to 23 were produced. In Table 1 below, Si, Fe, Mn, Cr, Zn, Ti, and Zr are inevitable impurities.

  The aluminum alloy ingot having the composition shown in Table 1 above is subjected to homogenization heat treatment, followed by hot rolling, followed by cold rolling and intermediate annealing, final cold rolling at a processing rate of 50%, An aluminum alloy plate having a thickness of 1.5 mm was used. Further, after being held at a temperature of 530 ° C. for 30 seconds, it was cooled at a rate of 5 ° C./second and No. Aluminum alloy plates 1 to 23 were produced. And about these aluminum alloy plates, various characteristics were evaluated by the following method.

  First, for each aluminum alloy plate, tensile test pieces according to JIS No. 5 were prepared so that the tensile direction was parallel to the rolling direction. Thereafter, a tensile test was performed to determine tensile strength, yield strength and elongation.

  In addition, the conductivity was measured using a Sigma Tester (model number 2.068) manufactured by Forster. Further, the crystal grain size was measured by etching the rolled surface of the aluminum alloy plate by the Barker method and cutting by observation with an optical microscope. Furthermore, the caulking workability is determined from a 90 ° bending test (R = 0.5), and those that do not have rough skin and cracks are evaluated as good, and those that are generated are evaluated as bad. It was determined.

The caulking strength is determined by the rigidity after caulking, and is proportional to the plate thickness and the proof stress. Therefore, the product of the plate thickness and the yield strength after 30% cold working corresponding to the caulking process was determined, and the product whose value was 230 mm · N / mm ² or more was determined to be the caulking strength pass.

For stress relaxation, first, an aluminum alloy plate was cold-rolled with a rolling rate of 30% assuming a caulking process, and cut into test pieces having a width of 10 mm and a length of 150 mm. FIG. 4 is a schematic diagram of a stress relaxation test. After that, as shown in FIG. 4, the test piece was deformed by applying a stress of 80% of the proof stress by the cantilever type described in the Japan Electronic Materials Industry Standard EMAS-3003. After measuring ₀ ), it was kept at 160 ° C. for 100 hours in that state, and after removing the stress, the deformation amount (ε) of the test piece was measured again. From the following mathematical formula 1, the stress relaxation rate was determined from the ratio of δ ₀ and ε, and a stress relaxation rate value of 50% or less was regarded as acceptable. The above evaluation results are shown in Table 2 below.

  As shown in Table 1 above, no. The aluminum alloy plates 1 to 12 are examples of the present invention and have a composition within the range regulated by the present invention. On the other hand, no. The aluminum alloy plates 13 to 23 are comparative examples that are out of the scope of the present invention. No. In the aluminum alloy plates Nos. 13 and 14, the Cu content is less than the lower limit value or exceeds the upper limit value of the range regulated by the present invention. In the aluminum alloy plates 15 and 16, the Mg content is less than the lower limit or exceeds the upper limit of the range regulated by the present invention. Furthermore, no. In the aluminum alloy plates 17 to 23, Si, Fe, Mn, Cr, Zn, Ti, and Zr, which are inevitable impurities, each exceed the upper limit of the range regulated by the present invention.

  As shown in Table 2 above, No. 1 satisfying the necessary conditions of the present invention. The aluminum alloy sheets 1 to 12 have excellent caulking workability, caulking strength, and stress relaxation characteristics because the composition, crystal grain size, and electrical conductivity are all within the range regulated by the present invention.

  On the other hand, no. The aluminum alloy plate No. 13 was inferior in stress relaxation characteristics because the Cu content was less than the lower limit of the range regulated by the present invention. No. The aluminum alloy plate No. 14 was inferior in caulking workability because the Cu content exceeded the upper limit of the present invention. No. The aluminum alloy plate of 15 had an inferior caulking strength because the Mg content was less than the lower limit of the range of the present invention. No. No. 16 aluminum alloy plate was inferior in stress relaxation characteristics because the Mg content exceeded the upper limit of the present invention. Furthermore, no. The aluminum alloy plate of No. 17 has an inferior stress relaxation property because the Si content exceeds the range of the present invention. The 18 aluminum alloy plate was inferior in stress relaxation characteristics because the Fe content exceeded the upper limit of the present invention. No. The aluminum alloy sheets 19 to 22 were inferior in stress relaxation characteristics because the contents of Mn, Cr, Zn or Ti exceeded the upper limit values regulated by the present invention. No. The aluminum alloy plate No. 23 was inferior in caulking workability because the Zr content exceeded the upper limit in the present invention.

  Next, as Example 2 of the present invention, No. 1 shown in Table 1 above was obtained. No. 2 using an aluminum alloy ingot having the composition of No. 2 and changing the plate thickness after the final cold rolling. 27 to 30 aluminum alloy plates were produced. In the manufacturing method, the aluminum alloy ingot is subjected to a homogenization heat treatment, followed by hot rolling, cold rolling and intermediate annealing, final cold rolling at a processing rate of 50%, and a sheet thickness of 0. A 4-level aluminum alloy plate of 9 to 3.3 mm was used. And after hold | maintaining for 30 seconds at the temperature of 530 degreeC, it cooled at the speed | rate of 5 degree-C / sec. No. 1 produced in this way. About the 27 thru | or 30 aluminum alloy board, the test similar to the above-mentioned Example 1 was done, and the characteristic was evaluated. Table 3 below shows these production conditions, and Table 4 below shows the evaluation results. In Table 3 and Table 4 below, No. 1 prepared in Example 1 was used as a standard sample. The production conditions and evaluation results of the aluminum alloy plate 2 are also shown.

  As shown in Table 4 above, the aluminum alloy plates No. 2, 27 and 28, which are examples of the present invention, are all within the range regulated by the present invention in terms of the composition, crystal grain size and electrical conductivity of the aluminum alloy plates. Excellent caulking workability, caulking strength and stress relaxation properties were exhibited. On the other hand, the plate thickness is thinner than the range of the present invention. No. 29 aluminum alloy plate is inferior in caulking strength, and the plate thickness is thicker than the range of the present invention. The 30 aluminum alloy plate was inferior in caulking workability.

  Next, as Example 3 of the present invention, an example and a comparative example relating to the method for manufacturing an aluminum alloy plate according to the second invention of the present application will be described. No. shown in Table 1 above. No. 2 using an aluminum alloy ingot having a composition of 2 and changing the processing rate in the final cold rolling after intermediate annealing. 24 to 26 aluminum alloy plates were produced. The manufacturing method is as follows. First, the aluminum alloy ingot is subjected to a homogenization heat treatment, followed by hot rolling, cold rolling and intermediate annealing, and the final cold rolling at a working rate of 4 to 5%. To obtain an aluminum alloy plate having a plate thickness of 1.5 mm. Next, it was kept at a temperature of 530 ° C. for 30 seconds and then cooled at a rate of 5 ° C./second. No. 1 produced in this way. About the 24 thru | or 26 aluminum alloy board, the test similar to the above-mentioned Example 1 was done, and the characteristic was evaluated. Table 5 below shows these production conditions, and Table 6 below shows the evaluation results. In Table 5 and Table 6 below, No. 1 prepared in Example 1 was used as a standard sample. The production conditions and evaluation results of the aluminum alloy plate 2 are also shown.

  As shown in Table 6 above, the composition, crystal grain size, and conductivity of the aluminum alloy plate are all within the range regulated by the present invention. The aluminum alloy plates 2 and 24 exhibited excellent caulking workability, caulking strength, and stress relaxation characteristics. On the other hand, the cold rolling process rate is lower than the range of the present invention, and the comparative example No. The 25 aluminum alloy plate exceeded the scope of the present invention, and the caulking workability was poor. Moreover, No. with a cold rolling rate higher than the range of this invention. The 26 aluminum alloy sheet had a crystal grain size lower than the range of the present invention, and the stress relaxation rate was inferior.

  Next, as Example 4 of the present invention, no. The aluminum alloy ingot having the composition of 2 is used, and the aluminum alloy ingot is subjected to homogenization heat treatment, followed by hot rolling, cold rolling and intermediate annealing, and final cold rolling at a processing rate of 50%. The aluminum alloy plate having a thickness of 1.5 mm was applied. And after heat-processing with various holding | maintenance temperature and time, it cooled at the speed | rate of 5 degree-C / sec, and No. 31 to 36 aluminum alloy plates were produced. Each aluminum alloy plate thus produced was tested in the same manner as in the first example to evaluate its characteristics. Table 7 below shows these production conditions, and Table 8 below shows the evaluation results. In Table 7 and Table 8 below, No. 1 prepared in Example 1 was used as a standard sample. The production conditions and evaluation results of the aluminum alloy plate 2 are also shown.

  The composition, crystal grain size, and electrical conductivity of the aluminum alloy plate are all within the range regulated by the present invention. The aluminum alloy sheets Nos. 2, 31 to 33 exhibited excellent caulking workability, caulking strength, and stress relaxation characteristics. On the other hand, the heat treatment temperature is lower than the range of the present invention, which is a comparative example of the present invention. No. 34 aluminum alloy sheet has a poor stress relaxation rate, and the heat treatment temperature is higher than the range of the present invention. As for the 35 aluminum alloy plate, a burning phenomenon occurred during the heat treatment, and a sound plate material could not be produced. In addition, the heat treatment time is longer than the range of the present invention. The 36 alloy plate had a crystal grain size exceeding the range of the present invention, and was poor in caulking workability.

  Next, as Example 5 of the present invention, No. 1 shown in Table 1 above was obtained. The aluminum alloy ingot having the composition 2 is used, and the aluminum alloy ingot is subjected to a homogenization heat treatment, followed by hot rolling, cold rolling and intermediate annealing, and final cold rolling at a processing rate of 50%. The aluminum alloy plate having a thickness of 1.5 mm was applied. And after hold | maintaining for 30 second on 530 degreeC temperature conditions, the cooling rate was cooled at 3 levels of 0.5 thru | or 5 degree-C / sec, and the aluminum alloy plate of No37 and 38 was produced. No. 1 produced in this way. About the aluminum alloy plate of 37 and 38, the test similar to the above-mentioned Example 1 was done, and the characteristic was evaluated. Table 9 below shows these production conditions, and Table 10 below shows the evaluation results. In Table 9 and Table 10 below, No. 1 prepared in Example 1 was used as a standard sample. The production conditions and evaluation results of the aluminum alloy plate 2 are also shown.

  As shown in Table 10 above, the composition, crystal grain size, and conductivity of the aluminum alloy plate are all within the range regulated by the present invention, and No. 1 is an example of the present invention. The aluminum alloy plates 2 and 37 exhibited excellent caulking workability, caulking strength, and stress relaxation characteristics. On the other hand, the cooling rate is slower than the range of the present invention, which is a comparative example of the present invention. The 38 aluminum alloy plate had a conductivity exceeding 50 IACS%, and the stress relaxation rate was inferior.

  Next, as an example 6 of the present invention, an example of an aluminum alloy terminal according to the third invention of the present application and a comparative example will be described. No. shown in Table 1 above. The aluminum alloy ingot having the composition 2 is used, and the aluminum alloy ingot is subjected to a homogenization heat treatment, followed by hot rolling, cold rolling and intermediate annealing, and final cold rolling at a processing rate of 50%. The aluminum alloy plate having a thickness of 1.5 mm was applied. And after hold | maintaining for 30 second on 530 degreeC temperature conditions, it cooled with the cooling rate of 5 degree-C / sec, and produced the aluminum alloy plate. After processing this aluminum alloy plate into the shape shown in FIGS. 1 (a) and 1 (b), a Ni plating film and a Sn plating film were formed on the surface by changing the thickness, respectively. 39-No. 45 terminals. At that time, the dimensions of each terminal were set such that the plate thickness T was 1.5 mm, the inner diameter A was about 6 mm, and the outer diameter B was 15 mm.

  And No. produced by the above-mentioned method. 39-No. The contact resistance, corrosion resistance, and manufacturing cost of 45 terminals were evaluated. FIG. 5A is a perspective view showing a method for measuring contact resistance, FIG. 5B is a perspective view showing the contact shown in FIG. 5A, and FIG. 5C shows its shape. It is a side view. The contact resistance was determined by forming a plating film on the surface of the aluminum alloy plate, cooling a terminal heated at 160 ° C. for 100 hours in the atmosphere at room temperature, and then cooling the electrical contact simulator shown in FIG. Used and measured by the 4-terminal method. As shown in FIGS. 5B and 5C, the measurement was performed by using a gold wire with a diameter of 1 mm bent on the contact 10 and setting the load ΔW to 5N. In this example, the case where the contact resistance value was 0.12 mΩ or less was regarded as acceptable.

  In the corrosion resistance test, after a plating film was formed, a terminal heated at 160 ° C. in the atmosphere for 100 hours was allowed to cool at room temperature, and then a 5 mass% NaCl aqueous solution was added for 48 hours at 35 ° C. Sprayed. As a result, the case where corrosion did not occur on the surface of the plating film was rated as “◯”, and the case where the plating film was corroded to form a hole on the surface and the internal aluminum alloy material also corroded was rated as “X”.

  As for the cost, a case where it is equivalent to the current product is indicated by ○, and a case where the cost is more effective than the current product is indicated by ×. The above results are summarized in Table 11 below.

  As shown in Table 11 above, no. The terminals 39 to 41 were excellent in all of contact resistance, corrosion resistance and cost. On the other hand, this is a comparative example of the present invention, in which the Ni plating film and the Sn plating film are thin. The terminal of 42 had a contact resistance of more than 0.12 mΩ and poor corrosion resistance. In addition, the thickness of the Ni plating film is thin. No. 43 terminal is inferior in corrosion resistance, and the Sn plating film thickness is thin. The terminal of 44 had a high contact resistance value. Furthermore, the Ni plating film and the Sn plating film are thick. Although the terminal of 45 was excellent in contact resistance and corrosion resistance, the manufacturing cost increased compared with the conventional product.

(A) is a top view which shows the storage battery electric wire board terminal for motor vehicles, (b) is the side view. (A) is a top view which shows the round board terminal for motor vehicles, (b) is the side view. (A) is a perspective view which shows an example of the state by which the aluminum alloy terminal of this invention was attached to wiring, (b) is an enlarged view which shows the connection part. It is a schematic diagram of the stress relaxation test in the aluminum alloy plate of this invention. (A) is a perspective view which shows the measurement measurement method of contact resistance, (b) is a perspective view which shows the contactor shown to (a), (c) is a side view which shows the shape.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1; Aluminum alloy plate 10; Contactor 11; Measuring object 12; Synchronous motor 13; Resistance meter 14;

Claims (6)

Cu: 0.2 to 0.9% by mass, Mg: 0.6 to 1.4% by mass, the balance is made of Al and inevitable impurities, and among the inevitable impurities, Si: 0.8% by mass %: Fe: 0.6 mass% or less, Mn: 0.15 mass% or less, Cr: 0.3 mass% or less, Zn: 0.3 mass% or less, Ti: 0.1 mass% or less, Zr: It has a composition regulated to 0.15% by mass or less, the plate thickness is greater than 1.0 mm and less than 3.0 mm, the crystal grain size is 35 to 300 μm, and the conductivity is 50% IACS or less. An aluminum alloy plate for caulking. 2. The aluminum alloy sheet for caulking according to claim 1, wherein the stress relaxation rate after applying 30% machining corresponding to caulking and further holding at 160 [deg.] C. for 100 hours is 50% or less. Cu: 0.2 to 0.9% by mass, Mg: 0.6 to 1.4% by mass, the balance is made of Al and inevitable impurities, and among the inevitable impurities, Si: 0.8% by mass %: Fe: 0.6 mass% or less, Mn: 0.15 mass% or less, Cr: 0.3 mass% or less, Zn: 0.3 mass% or less, Ti: 0.1 mass% or less, Zr: After hot rolling an aluminum alloy plate having a composition regulated to 0.15% by mass or less, after cold rolling at a processing rate of 7 to 60%, and thereafter holding at a temperature of 500 to 570 ° C. for 1 hour or less, By performing a heat treatment to cool at a rate of 1 ° C./second or more, the plate thickness is greater than 1.0 mm and less than 3.0 mm, the crystal grain size is 35 μm to 300 μm, and the conductivity is 50% IACS or less. Caulking characterized by producing an aluminum alloy sheet Manufacturing method of aluminum alloy plate for processing. The method for producing an aluminum alloy plate for caulking according to claim 3, wherein cold rolling and intermediate annealing are performed between the hot rolling and cold rolling with a processing rate of 7 to 60%. A Ni plating film having a thickness of 0.5 to 5.0 μm is formed on the surface of the aluminum alloy plate for caulking according to claim 1, and further a thickness of 1 to 10 μm is formed on the Ni plating film. A terminal made of an aluminum alloy, characterized in that an Sn plating film is formed. The aluminum alloy terminal according to claim 5, wherein the aluminum alloy terminal is used as an automotive part.

Images