JP3704779B2 - Joining member, composite material, and method of manufacturing the composite material - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a joining member, a composite material, and a method for manufacturing the composite material, and more particularly to a joining member, a composite material, and a method for manufacturing the composite material used in an electromagnetic heating cooker.
[0002]
[Background Art and Problems to be Solved by the Invention]
Conventionally, an inner pot of a rice cooker used for an electromagnetic heating cooker has a magnetic metal plate such as iron or stainless steel as a heating element, and a heat transfer plate made of an aluminum alloy that transfers heat generated from the magnetic metal plate. It is comprised by the provided composite material. The inner pot of the rice cooker is formed by subjecting this composite material to press forming such as deep drawing so that the heat transfer plate is on the inside. In addition, the inner surface of the inner pot is coated with a fluororesin to prevent sticking of cooked rice.
[0003]
This composite material has been conventionally formed by a method of combining a magnetic metal plate and a heat transfer plate by roll rolling (see Japanese Patent Publication Nos. 54-3468 and 54-9985).
[0004]
In such a roll rolling method, since the aluminum alloy is compressed and joined, there is a problem that wrinkles occur in the aluminum alloy. Furthermore, the composite material formed by this method has a problem that the thickness variation is large.
[0005]
As an improved technique for solving such a problem, there is a method based on hot uniaxial pressurization disclosed in JP-A-6-15465 and JP-A-6-179083. In the method described in JP-A-6-15465, an iron alloy and an aluminum alloy are brought into contact with each other and 400 kgf / cm in an atmosphere of 450 ° C. or higher and 600 ° C. or lower. ² The above pressure is applied to join both alloys. Further, in the method described in JP-A-6-179083, copper is interposed between an aluminum alloy and an iron alloy so that both alloys are brought into contact with each other, and 250 kgf / cm in an atmosphere of 250 ° C. or higher and 450 ° C. or lower. ² The above pressure is applied to join both alloys.
[0006]
In such a method, although the above-mentioned problems have been improved, there is a case in which sufficient bonding strength between the aluminum alloy and the iron alloy cannot be obtained, and the yield is low. In addition, in order to improve the bonding strength and the yield, there has been a problem that when a higher temperature treatment is performed, when the fluororesin is applied to the aluminum alloy at a high temperature of 300 ° C. or higher, the fluororesin is melted. Furthermore, there is a problem that it cannot be used for joining metals that are distorted at high temperatures.
[0007]
Accordingly, the present invention has been made to solve the above-described problems, and provides a bonding member, a composite material, and a method for manufacturing the composite material, which can be bonded at a low temperature and obtain a strong bonding force. Objective.
[0008]
[Means for Solving the Problems]
The bonding member of the present invention includes a metal layer and a bonding layer containing copper formed on one surface of the metal layer, and the average crystal grain size of copper contained in the bonding layer is 0.10 μm or more 0.12 It is a member for joining characterized by being below μm.
[0009]
Generally, in diffusion bonding, the crystal grain size and temperature of the diffusion layer are important factors. First, regarding temperature, the diffusion rate of atoms is generally proportional to temperature. This is presumably because the energy of the diffusing atoms is proportional to the temperature. For this reason, when diffusion bonding is performed at a high temperature, atoms are sufficiently diffused, so that bonding can be reliably performed.
[0010]
However, when diffusion bonding is performed at a low temperature, the energy of the diffusing atoms is small. Here, when the crystal grain size is small, there are many grain boundaries of crystal grains. Therefore, diffusion through the grain boundary becomes remarkable, and the frequency of exchange of atoms at the interface necessary for bonding increases. Therefore, even if the crystal grain size is small, sufficient bonding is performed even at a low temperature.
[0011]
As a result of diligent research based on these ideas, the present inventors have found that the average crystal grain size of the diffusion metal is 0.10 μm or more 0.12 It has been found that sufficient diffusion bonding is performed at a low temperature (300 ° C. or less, preferably 250 ° C. or less) below μm.
[0012]
That is, in the bonding member according to the present invention, the average crystal grain size of copper in the bonding layer containing copper formed on one surface of the metal layer is 0.10 μm or more 0.12 It is below μm. Therefore, sufficient diffusion bonding can be performed at a low temperature (300 ° C. or less, preferably 250 ° C. or less) by bringing the bonding layers into contact with each other and performing diffusion bonding.
[0013]
As described above, according to the present invention, it is possible to reliably perform metal bonding at a low temperature, so that it is possible to improve the yield. Further, since bonding can be performed at a low temperature, there is an effect that bonding can be performed in a state where an organic resin is applied to the surface of the metal layer. Further, there is an effect that distortion due to heat is not generated.
[0014]
Moreover, it is preferable that a joining layer is a copper plating layer.
In the joining member configured as described above, the joining layer can be easily formed by performing copper plating on the surface of the metal layer.
[0015]
Moreover, it is preferable that a metal layer contains the iron alloy containing chromium.
As this metal layer, almost all metal elements can be used. However, when used in a cooker that uses derivatized heat, the metal layer should be a metal that becomes a heating element due to the flow of eddy currents generated by sustained high frequencies. Needless to say.
[0016]
In this heating method using high frequency, for example, when a metal layer is arranged in an alternating magnetic field oscillated at a frequency of about 20 kHz, an eddy current is generated, and heat is generated by the Joule heat of this current. For this reason, in order to heat efficiently, there are restrictions on the material of the metal layer, the thickness of the metal layer, and the like. This is because the influence of the skin effect that occurs when high-frequency current flows in the metal layer is significant.
[0017]
Whether or not a metal material is suitable as a heating element of an electromagnetic cooker is determined by the skin resistance at the operating frequency. For example, when the skin resistance is very small, such as aluminum, the calorific value is small even if eddy current is generated, so that a sufficient output cannot be obtained. Although SUS430 is exclusively used for the electromagnetic heat generating composite plate manufactured by roll rolling, it is considered that the material is suitable for heat generation even from the viewpoint of skin resistance. In this invention, although a metal layer is not limited to SUS430, the material which increased specific resistance by alloying centering on Fe, ie, the material which enlarged skin resistance, can be utilized as a metal layer. As a material to be alloyed, chromium or nickel can be selected in consideration of corrosion resistance. For an electromagnetic cooker, an iron alloy containing chromium excellent in corrosion resistance and heat generation is considered preferable.
[0018]
Furthermore, the bonding layer is preferably formed on the metal layer with a nickel layer formed on one surface of the metal layer interposed.
[0019]
In the joining member configured as described above, the joining property between the iron alloy containing chromium in the metal layer and the nickel layer formed on the metal layer is good. Further, the bonding property between the nickel layer and copper in the bonding layer formed on the nickel layer is also good. Therefore, the bonding layer and the metal layer can be reliably bonded.
[0020]
Moreover, it is preferable that a metal layer contains aluminum.
Furthermore, the bonding layer is preferably formed on the metal layer with a zinc layer formed on one surface of the metal layer and a nickel layer formed on the zinc layer interposed. .
[0021]
In the joining member configured as described above, the joining property between the aluminum in the metal layer and the zinc layer formed on the metal layer is good. Also, the bondability between the zinc layer and the nickel layer formed on the zinc layer is good. Furthermore, the bondability between the nickel layer and copper in the bonding layer formed on the nickel layer is also good. Therefore, the metal layer and the bonding layer are securely bonded.
[0022]
In addition, the composite material of the present invention includes a first metal layer, a bonding layer containing copper formed on one surface of the first metal layer, and the first metal layer with the bonding layer interposed therebetween. And a second metal layer formed on one surface of the copper, and an average crystal grain size of copper contained in the bonding layer is 0.10 μm or more 0.12 It is characterized by being not more than μm.
[0023]
In the composite material thus configured, the average crystal grain size formed on the surface of the first metal layer is 0.10 μm or more 0.12 The average crystal grain size formed on the part of the bonding layer containing copper that is not more than μm and the surface of the second metal layer is 0.10 μm or more 0.12 When a part of the bonding layer containing copper of μm or less is bonded by copper diffusion bonding, both metal layers can be bonded reliably at a low temperature of 300 ° C. or less.
[0024]
Moreover, it is preferable that a 1st metal layer contains aluminum and a 2nd metal layer contains the iron alloy containing chromium.
[0025]
Further, a zinc layer formed on one surface of the first metal layer and a nickel layer formed on the zinc layer are interposed between the first metal layer and the bonding layer. In addition, a nickel layer is preferably interposed between the bonding layer and the second metal layer.
[0026]
In the composite material thus configured, the bondability between the aluminum in the first metal layer and the zinc layer formed thereon is good. Also, the bondability between the zinc layer and the nickel layer formed thereon is good. Furthermore, the bondability between the nickel layer and copper in the bonding layer formed thereon is good. Therefore, the first metal layer and the bonding layer are reliably bonded.
[0027]
Also, the bondability between the iron in the second bonding layer and the nickel layer formed thereon is good. Also, the bondability between the nickel layer and copper in the bonding layer formed thereon is good. Therefore, the second metal layer and the bonding layer are reliably bonded.
[0028]
Moreover, it is preferable that the organic substance layer is formed on the other surface of the 1st metal layer.
[0029]
The organic layer is preferably a fluororesin.
In the composite material configured as described above, the surface on which the organic material layer such as the fluororesin is formed does not adhere to dirt. Therefore, it can be used as a cooking device for electromagnetic heating.
In the method for producing a composite material of the present invention, first, a first metal layer and a first bonding layer containing copper formed on one surface of the first metal layer are provided. A first bonding member having an average crystal grain size of copper contained in one bonding layer of 1.0 μm or less is prepared. A second metal layer and a second bonding layer containing copper formed on one surface of the second metal layer, and an average crystal grain size of copper contained in the second bonding layer is A second bonding member having a thickness of 1.0 μm or less is prepared. Then, the first bonding member and the second bonding member are overlapped so that the first bonding layer and the second bonding layer face each other. The superposed first and second joining members are pressurized and heated to a predetermined temperature.
[0030]
In the method of manufacturing a composite material configured as described above, the average crystal grain size of copper in the first and second bonding layers is 1.0 μm or less, and the first and second copper are diffused and bonded to each other. The joining members are joined. Therefore, the first and second joining members can be reliably joined at a low temperature of 300 ° C. or lower.
[0031]
In the step of preparing the first bonding member, it is preferable to form a copper plating layer on one surface of the first metal layer.
[0032]
In the step of preparing the second bonding member, it is preferable to form a copper plating layer on one surface of the second metal layer.
[0033]
In the method for manufacturing a composite material configured as described above, the bonding layer can be easily formed by performing copper plating on the surfaces of the first and second bonding members.
[0034]
Moreover, it is preferable that a 1st metal layer contains aluminum and a 2nd metal layer contains the iron alloy containing chromium. Further preferably, the step of preparing the first bonding member includes forming a zinc layer on one surface of the first metal layer, forming a nickel layer on the zinc layer, Forming a first bonding layer on the nickel layer and coating at least a surface of the first bonding layer with benzotriazole or a derivative thereof; The step of preparing the second bonding member includes forming a nickel layer on one surface of the second metal layer, forming a second bonding layer on the nickel layer, It is preferable to include covering at least the surface of the two bonding layers with benzotriazole or a derivative thereof.
[0035]
In the manufacturing method of the composite material thus configured, the bondability between the aluminum in the first metal layer and the zinc layer formed thereon is good. Also, the bondability between the zinc layer and the nickel layer formed thereon is good. Furthermore, the bondability between the nickel layer and the first bonding layer containing copper formed thereon is good. Therefore, the first metal layer and the first bonding layer can be reliably bonded. Further, by coating at least the surface of the first bonding layer with benzotriazole or a derivative thereof, oxidation of copper in the first bonding layer can be prevented. Therefore, copper diffusion bonding can be reliably performed. Further, nickel having good bondability is interposed between both iron in the second metal layer and copper in the second bonding layer, so that the bonding between the second metal layer and the second bonding layer is ensured. Can be. Further, by coating at least the surface of the second bonding layer with benzotriazole or a derivative thereof, oxidation of copper in the second bonding layer can be prevented. Therefore, copper diffusion bonding can be reliably performed.
[0036]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0037]
1A and 1B are cross-sectional views schematically showing a joining member of the present invention. Referring to FIG. 1 (A), a bonding member 1 includes a fluororesin layer 2, an aluminum alloy layer 3, a zinc layer 4, a nickel layer 5, and a copper plating layer 6. A zinc layer 4 is formed so as to be in contact with the aluminum alloy layer 3. A nickel layer 5 is formed in contact with the zinc layer 4. A copper plating layer 6 is formed in contact with the nickel layer 5. The average crystal grain size of copper in the copper plating layer 6 is 1.0 μm or less. The zinc layer 4 and the nickel layer 5 function to strengthen the bonding between the aluminum alloy layer 3 and the copper plating layer 6. Instead of the zinc layer 4 and the nickel layer 5, a metal layer having good bondability with both aluminum and copper may be interposed between the aluminum alloy layer and the copper plating layer 6. A fluororesin layer 2 is formed on the aluminum alloy layer 3. The fluororesin layer 2 functions to prevent the surface of the aluminum alloy layer 3 from being corroded and to prevent the surface of the aluminum alloy layer 3 from becoming dirty.
[0038]
Referring to FIG. 1B, the second bonding member 7 includes a fluororesin layer 11, an iron alloy layer 10, a nickel layer 9, and a copper plating layer 8. A fluororesin layer 11 is formed in contact with the iron alloy layer 10. The fluororesin layer 11 functions to prevent the surface of the iron alloy layer 10 from being corroded and to prevent the surface of the iron alloy layer 10 from becoming dirty. A nickel layer 9 is formed on the iron alloy layer 10. A copper plating layer 8 is formed on the nickel layer 9. The nickel layer 9 functions to strengthen the bonding between the copper plating layer 8 and the iron alloy layer 10. Instead of the nickel layer 9, a metal layer having good bondability with both copper and iron may be interposed between the copper plating layer 8 and the iron alloy layer 10. The average crystal grain size of copper in the copper plating layer 8 is 1.0 μm or less.
[0039]
In addition, in FIG. 1 (A), since the joining property of the aluminum alloy layer 3 and the copper plating layer 6 is not so preferable, the zinc layer 4 and the nickel layer 5 are interposed between them. However, if a layer made of a metal having good bonding properties with the copper plating layer 6 is used instead of the aluminum alloy layer 3, there is no need to interpose the zinc layer 4 or the nickel layer 5.
[0040]
Also in FIG. 1B, the nickel layer 9 is interposed because the bondability between the iron alloy layer 10 and the copper plating layer 8 is not so preferable. However, if a layer made of a metal having good bonding properties with the copper plating layer 8 is used instead of the iron alloy layer 10, the nickel layer 9 does not need to be interposed. Further, if it is not necessary to protect the surfaces of the aluminum alloy layer 3 and the iron alloy layer 10, the fluororesin layers 2 and 11 need not be provided.
[0041]
FIG. 2 is a cross-sectional view schematically showing the composite material of the present invention. Referring to FIG. 2, the composite material 12 is obtained by joining a first joining member 1 and a second joining member 7. The first joining member 1 is shown in FIG. The second joining member 7 is as shown in FIG. When the copper plating layer 6 of the first bonding member 1 and the copper plating layer 8 of the second bonding member 7 are diffusion bonded, the first bonding member 1 and the second bonding member 7 are bonded. are doing.
[0042]
In the composite material 12 thus configured, two types of metals having different properties can be reliably bonded. Here, if an eddy current is passed through the iron alloy layer 10, heat is generated from the iron alloy layer 10. Heat generated from the iron alloy layer 10 is transferred to the aluminum alloy layer 3 through the nickel layer 9, the copper plating layers 8 and 6, the nickel layer 5, and the zinc layer 4. Therefore, in the composite material 12, what was placed on the fluororesin layer 2 can be efficiently heated. Therefore, this composite material 12 can be used for an electromagnetic heating cooker. Furthermore, other metals can be used instead of the aluminum alloy layer 3 and the iron alloy layer 10 as long as a copper plating process can be performed. In addition to metals, ceramics, cermets, plastics, etc. can be used in place of the aluminum alloy layer 2 and the iron alloy layer 10 as long as they can be plated with copper. Can be considered.
[0043]
Next, a method for manufacturing the composite material 12 shown in FIG. 2 will be described.
First, a first joining member 1 and a second joining member 7 shown in FIGS. 1A and 1B are prepared. Here, the configurations of the first and second joining members 1 and 7 have already been described, and will be omitted. Here, if the surfaces of the copper plating layers 6 and 8 are oxidized, copper diffusion bonding does not occur in the next step. Therefore, the surfaces of the copper plating layers 6 and 8 are preferably covered with an organic resin (for example, benzotriazole, hereinafter referred to as BTA). However, since this organic resin needs to be completely volatilized in the next step, it is preferable that the organic resin be completely volatilized at 300 ° C. or lower.
[0044]
Next, the copper plating layer 6 of the first bonding member 1 and the copper plating layer 8 of the second bonding member 7 face each other. At this time, when the copper plating layers 6 and 8 are covered with BTA, the copper plating layers 6 and 8 do not contact each other. In this state, 500 kgf / cm in a direction perpendicular to the interface between the copper plating layers 6 and 8. ² Apply a moderate pressure and expose to a heated atmosphere of about 250 ° C. The pressure at this time is sufficient if it is sufficient for the joint surfaces to come into contact with each other, and varies depending on the uneven shape of the joint surfaces and is optimized. Thereby, BTA which coat | covers the copper plating layers 6 and 8 volatilizes, and the copper plating layers 6 and 8 contact | connect. Further, the first bonding member 1 and the second bonding member 7 are bonded by diffusion bonding of copper in the copper plating layers 6 and 8.
[0045]
In the method of manufacturing a composite material configured as described above, two types of members can be reliably bonded at 300 ° C. or lower, preferably 250 ° C. or lower. For this reason, even a member that generates strain when heated to a temperature exceeding 300 ° C. or 250 ° C. can be joined without causing strain. Further, even when an organic resin or the like that dissolves and decomposes when heated to a temperature exceeding 300 ° C. or 250 ° C. is formed on a part of the members, the members can be joined to each other.
[0046]
【Example】
Embodiments of the present invention will be described below with reference to the drawings.
[0047]
FIG. 3 is a cross-sectional view schematically showing the aluminum member 21 of the present invention. Referring to FIG. 3, the material of the aluminum alloy layer 22 is JIS3004 series aluminum alloy MG-110 (manufactured by Sumitomo Light Metal; Mg 0.6 to 0.8 wt%, Mn 0.9 to 1.1 wt% included) A circle plate having a thickness of 1.5 mm and a diameter of 360 mm was used. In order to coat the surface of the aluminum alloy layer 22 with a fluororesin, the surface of the aluminum alloy layer 22 is coated with 20 coulomb / cm in a NaCl aqueous solution. ² Electrolytic etching was performed with the amount of electricity, and fine irregularities were provided on the surface. A fluororesin dispersion was applied to this surface, and the fluororesin layer 33 was formed by baking.
[0048]
Next, in order to remove the oxide existing on the surface of the aluminum alloy layer 22 on the surface of the aluminum alloy layer 22 opposite to the surface on which the fluororesin layer 33 is formed, this surface was subjected to alkali etching treatment. . Residues consisting of oxides remaining on the surface of the aluminum alloy layer 22 and segregated materials by alkali etching were removed with a strong acid. This surface was immersed in a zinc solution, and zinc was substituted and deposited while dissolving the surface of the aluminum alloy layer 22 to form a zinc layer 23. Next, a watt bath (bath temperature 50 ° C., cathode current density 5 A / dm) is used as a nickel plating bath on the surface of the zinc layer 23. ² ) Was applied to form a nickel layer 24.
[0049]
As a plating solution, 220 g / dm ^Three Copper sulfate in water, 50 g / dm ^Three Of sulfuric acid, 0.5cm ^Three / Dm ^Three Uemura Kogyo Rebco 300B (trade name), 5cm ^Three / Dm ^Three An aqueous solution containing Rebuco 300C (trade name) manufactured by Uemura Kogyo was prepared. The surface of the nickel layer 24 was immersed in this plating solution, and copper plating was performed for 10 minutes by 3V constant voltage electrolysis. Further, when the plating solution decreased, appropriate amounts of Uemura Kogyo Rebco 300A (trade name) and Uemura Kogyo Rebuco 300B (trade name) were replenished. As a result, a copper plating layer 25 was formed on the surface of the nickel layer 24.
[0050]
When the cross section of the copper plating layer 25 was etched with a focused gallium ion beam and the fracture surface was observed with an electron microscope, the average crystal grain size of copper in the copper plating layer 25 was 0.10 μm. Next, the member including the aluminum alloy layer 22 was immersed in an isopropyl alcohol solution containing 4% by weight of BTA for 1 minute to form the aluminum member 21 entirely covered with the BTA 26.
[0051]
FIG. 4 is a cross-sectional view schematically showing the iron member 27 of the present invention. Referring to FIG. 4, JIS 430 iron-chrome alloy (a circle plate having a size of 0.5 mm thickness and 360 mmφ) was used as the stainless steel layer 30. In order to coat the surface of the stainless steel layer 30 with a fluororesin, the surface of the stainless steel alloy layer 30 is coated with 20 coulomb / cm in a NaCl aqueous solution. ² Electrolytic etching was performed with the amount of electricity, and fine irregularities were provided on the surface. A fluororesin dispersion was applied to this surface, and a fluororesin layer 34 was formed by baking.
[0052]
Next, in order to remove oil and chromium oxide on the surface opposite to the surface on which the fluororesin layer 34 of the stainless alloy layer 30 was formed, this surface was subjected to anodic electrolysis in an alkaline solution. After removing the residue with a strong acid, a nickel layer 29 having a thickness of about 1 μm was formed on the surface of the stainless alloy layer 30 using a wood bath as a nickel plating bath.
[0053]
As a plating solution, 220 g / dm ^Three Copper sulfate in water, 50 g / dm ^Three Of sulfuric acid, 0.5cm ^Three / Dm ^Three Uemura Kogyo Rebco 300B (trade name), 5cm ^Three / Dm ^Three An aqueous solution containing Rebuco 300C manufactured by Uemura Kogyo was prepared. The surface of the nickel layer 24 was immersed in this plating solution, and copper plating was performed for 10 minutes by 3V constant voltage electrolysis. Further, when the plating solution decreased, appropriate amounts of Uemura Kogyo Rebco 300A (trade name) and Uemura Kogyo Rebuco 300B (trade name) were replenished. As a result, a copper plating layer 28 was formed on the surface of the nickel layer 24.
[0054]
The surface of the nickel layer 29 was immersed in this plating solution, and copper plating was performed for 10 minutes by constant voltage electrolysis of 3V. As a result, a copper plating layer 28 was formed on the surface of the nickel layer 29.
[0055]
When the cross section of the copper plating layer 28 was etched with a focused gallium ion beam and the fracture surface was observed with an electron microscope, the average crystal grain size of copper in the copper plating layer 28 was 0.12 μm. Next, the member including the stainless alloy layer 30 was immersed in an isopropyl alcohol solution containing 4% by weight of BTA to form the iron member 27 whose entire surface was covered with the BTA 31.
[0056]
As described above, the aluminum member 21 and the iron member 27 of the present invention were formed.
Next, the manufacturing method of the composite material of this invention is demonstrated with reference to figures.
[0057]
FIG. 5 is a cross-sectional view schematically showing the method for producing a composite material of the present invention. Referring to FIG. 5, aluminum member 21 shown in FIG. 3 and iron member 27 shown in FIG. 4 were overlapped so that copper plating layers 25 and 28 face each other. Next, about 500 kgf / cm in the direction shown by the arrow 40 on the aluminum member 21 and the iron member 27. ² And kept in a vacuum at a temperature of 250 ° C. for 1 hour. Thereby, BTA26 and 31 volatilized completely and the copper plating layers 25 and 28 joined by diffusion bonding.
[0058]
FIG. 6 is a cross-sectional view schematically showing the composite material of the present invention manufactured by the manufacturing method shown in FIG. Referring to FIG. 6, the composite material 32 is obtained by diffusing the copper plating layers 25 and 28 in the aluminum member 21 shown in FIG. 3 excluding the BTA 26 and the iron member 27 shown in FIG. 4 excluding the BTA 31. It is joined by joining.
[0059]
FIG. 7 is a schematic diagram of an apparatus used for the peeling test of the composite material. Referring to FIG. 7, the end portion of iron member 27 was bent 90 °, and this end portion was fixed to fixing base 200. The end of the aluminum member 21 was bent 90 °, and a load was applied to the end in the direction indicated by the arrow 100. The load at which the aluminum member 21 and the iron member 27 peel was measured, and the value of this load was divided by the value of the width of the composite material 32 to obtain the adhesive strength.
[0060]
The adhesive strength was 40 kgf / cm or more. Further, the fracture site was inside the aluminum, and aluminum cohesive fracture occurred.
[0061]
(Comparative example)
Hereinafter, a comparative example will be described.
[0062]
As a comparative example, an aluminum member 21 shown in FIG. 3 was manufactured in substantially the same manner as in the above example. In the manufacturing method, the difference from the embodiment is that when the copper plating layer 25 is formed on the surface of the nickel layer 24, Rebco 300B (trade name) manufactured by Uemura Kogyo was removed from the plating solution. Moreover, when the plating solution decreased, only Rebco 300A (trade name) manufactured by Uemura Kogyo was replenished. Thereby, the average crystal grain size of copper in the copper plating layer 25 became 0.7 μm.
[0063]
Next, an iron member 27 shown in FIG. 4 was manufactured in substantially the same manner as in the above example. In the manufacturing method, the difference from the embodiment is that when the copper plating layer 28 is formed on the surface of the nickel layer 29, the Rebuco 300B (trade name) manufactured by Uemura Kogyo was removed from the plating solution. Moreover, when the plating solution decreased, only Rebco 300A (trade name) manufactured by Uemura Kogyo was replenished. As a result, the average crystal grain size of copper in the copper plating layer 28 was 1.2 μm.
[0064]
A composite material was formed in the same manner as in the above example using the aluminum member and the iron member thus manufactured.
[0065]
Next, a peel test was performed in the same manner as in the example, and the adhesive strength of the composite material was measured. The adhesive strength was 5 kgf / cm. The fracture site was the interface where the two copper plating layers were in contact.
[0066]
An attempt was made to form this composite material into the shape of an inner pot for an electromagnetic cooker, but it could be carried out without problems.
[0067]
It should be understood that the examples and embodiments disclosed herein are illustrative and non-restrictive in every respect. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view schematically showing a joining member of the present invention.
FIG. 2 is a cross-sectional view schematically showing a composite material of the present invention.
FIG. 3 is a cross-sectional view schematically showing an aluminum member of the present invention.
FIG. 4 is a cross-sectional view schematically showing an iron member of the present invention.
FIG. 5 is a cross-sectional view schematically showing a state in which the aluminum member and the iron member of the present invention are joined.
FIG. 6 is a cross-sectional view schematically showing a composite material of the present invention.
FIG. 7 is a schematic view of an apparatus used for a composite peel test.
[Explanation of symbols]
1 1st member for joining
3 Aluminum alloy layer
6,8 Copper plating layer
7 Second joining member
10 Iron alloy layer

Claims (15)

A joining member for joining dissimilar metals,
A metal layer;
A bonding layer containing copper formed on one surface of the metal layer,
A joining member, wherein an average crystal grain size of copper contained in the joining layer is 0.10 μm or more and 0.12 μm or less.   The bonding member according to claim 1, wherein the bonding layer is a copper plating layer.   The joining member according to claim 1, wherein the metal layer includes an iron alloy containing chromium.   The bonding member according to claim 3, wherein the bonding layer is formed on the metal layer with a nickel layer formed on one surface of the metal layer interposed therebetween.   The joining member according to claim 1, wherein the metal layer includes aluminum.   The bonding layer is formed on the metal layer by interposing a zinc layer formed on one surface of the metal layer and a nickel layer formed on the zinc layer. The joining member according to claim 5, wherein the joining member is characterized in that: A composite material in which dissimilar metals are joined,
A first metal layer;
A bonding layer comprising copper formed on one surface of the first metal layer;
A second metal layer formed on one surface of the first metal layer with the bonding layer interposed therebetween,
An average crystal grain size of copper contained in the bonding layer is 0.10 μm or more and 0.12 μm or less.   The composite material according to claim 7, wherein the first metal layer includes aluminum, and the second metal layer includes an iron alloy containing chromium.   A zinc layer formed on the surface of the first metal layer and a nickel layer formed on the zinc layer are interposed between the first metal layer and the bonding layer. The composite material according to claim 8, wherein a nickel layer is interposed between the bonding layer and the second metal layer.   The composite material according to claim 9, wherein an organic material layer is formed on the other surface of the first metal layer.   The composite material according to claim 10, wherein the organic material layer includes a fluororesin. A method of manufacturing a composite material in which different kinds of metals are joined,
A first metal layer and a first bonding layer containing copper formed on one surface of the first metal layer, wherein an average crystal grain size of copper contained in the first bonding layer is Preparing a first bonding member having a thickness of 1.0 μm or less;
A second metal layer, and a second bonding layer containing copper formed on one surface of the second metal layer, wherein an average crystal grain size of copper contained in the second bonding layer is Preparing a second bonding member having a thickness of 1.0 μm or less;
Superimposing the first bonding member and the second bonding member such that the first bonding layer and the second bonding layer face each other;
A method for producing a composite material, comprising the steps of pressurizing and heating the superimposed first and second joining members to a predetermined temperature.   The method for producing a composite material according to claim 12, wherein the step of preparing the first bonding member includes forming a copper plating layer on one surface of the first metal layer.   The method for producing a composite material according to claim 12, wherein the step of preparing the second bonding member includes forming a copper plating layer on one surface of the second metal layer. The first metal layer comprises aluminum;
The second metal layer includes an iron alloy containing chromium,
The step of preparing the first bonding member includes forming a zinc layer on one surface of the first metal layer, forming a nickel layer on the zinc layer, and the nickel layer. Forming the first bonding layer on the substrate, and coating at least the surface of the first bonding layer with benzotriazole or a derivative thereof,
The step of preparing the second bonding member includes forming a nickel layer on one surface of the second metal layer, and forming the second bonding layer on the nickel layer. The method for producing a composite material according to any one of claims 12 to 14, comprising covering at least the surface of the second bonding layer with benzotriazole or a derivative thereof.

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