KR100983960B1 - Bonding method of dissimilar materials made from metals and bonding structure thereof - Google Patents

Bonding method of dissimilar materials made from metals and bonding structure thereof Download PDF

Info

Publication number
KR100983960B1
KR100983960B1 KR1020080028895A KR20080028895A KR100983960B1 KR 100983960 B1 KR100983960 B1 KR 100983960B1 KR 1020080028895 A KR1020080028895 A KR 1020080028895A KR 20080028895 A KR20080028895 A KR 20080028895A KR 100983960 B1 KR100983960 B1 KR 100983960B1
Authority
KR
South Korea
Prior art keywords
material
dissimilar
interface
current
material interface
Prior art date
Application number
KR1020080028895A
Other languages
Korean (ko)
Other versions
KR20080089246A (en
Inventor
시게유끼 나까가와
겐지 미야모또
Original Assignee
닛산 지도우샤 가부시키가이샤
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority to JP2007092461 priority Critical
Priority to JPJP-P-2007-00092461 priority
Priority to JPJP-P-2007-00307345 priority
Priority to JP2007307345A priority patent/JP5376391B2/en
Application filed by 닛산 지도우샤 가부시키가이샤 filed Critical 닛산 지도우샤 가부시키가이샤
Publication of KR20080089246A publication Critical patent/KR20080089246A/en
Application granted granted Critical
Publication of KR100983960B1 publication Critical patent/KR100983960B1/en

Links

Images

Classifications

    • BPERFORMING OPERATIONS; TRANSPORTING
    • B23MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23KSOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
    • B23K11/00Resistance welding; Severing by resistance heating
    • B23K11/16Resistance welding; Severing by resistance heating taking account of the properties of the material to be welded
    • B23K11/20Resistance welding; Severing by resistance heating taking account of the properties of the material to be welded of different metals
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B23MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23KSOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
    • B23K11/00Resistance welding; Severing by resistance heating
    • B23K11/24Electric supply or control circuits therefor
    • B23K11/25Monitoring devices
    • B23K11/252Monitoring devices using digital means
    • B23K11/256Monitoring devices using digital means the measured parameter being the inter-electrode electrical resistance
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B23MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23KSOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
    • B23K11/00Resistance welding; Severing by resistance heating
    • B23K11/34Preliminary treatment
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B23MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23KSOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
    • B23K35/00Rods, electrodes, materials, or media, for use in soldering, welding, or cutting
    • B23K35/22Rods, electrodes, materials, or media, for use in soldering, welding, or cutting characterised by the composition or nature of the material
    • B23K35/226Non-corrosive coatings; Primers applied before welding
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B23MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23KSOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
    • B23K2103/00Materials to be soldered, welded or cut
    • B23K2103/08Non-ferrous metals or alloys
    • B23K2103/15Magnesium or alloys thereof
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B23MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23KSOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
    • B23K2103/00Materials to be soldered, welded or cut
    • B23K2103/18Dissimilar materials
    • B23K2103/20Ferrous alloys and aluminium or alloys thereof

Abstract

The present invention relates to a method of joining dissimilar metal materials and thus a joining structure. Three or more of the to-be-joined materials are piled up so that a dissimilar material interface and a homogeneous material interface may be formed. For example, a first electric current is energized between an aluminum alloy plate, a galvanized steel plate, and a bare steel sheet in the order of three sheets of stacked sheets. A nugget is formed at the interface between a galvanized steel sheet and a bare steel sheet. Thereafter, a second current larger than the first current is energized to form a nugget at the interface between the aluminum alloy plate and the galvanized steel sheet.
Dissimilar material interface, homogeneous material interface, aluminum alloy plate, galvanized steel plate, bare steel plate

Description

Bonding method of dissimilar metal materials and its bonding structure {BONDING METHOD OF DISSIMILAR MATERIALS MADE FROM METALS AND BONDING STRUCTURE THEREOF}

TECHNICAL FIELD The present invention relates to a joining technique using resistive welding of dissimilar metal materials such as steel materials and aluminum alloy materials, and structures thereof. In particular, the present invention relates to a joint formed by stacking three or more sheets and having a dissimilar material interface and a homogeneous material interface.

In the case of joining dissimilar metals, if the joining process used is the same as that used for joining the same material, a weak intermetallic compound is formed and sufficient joint strength is not obtained. For example, in the case of bonding the aluminum alloy and steel, and is formed with a high hardness weak intermetallic compound is also such as Fe 2 Al 5 or FeAl 3. In order to secure the joint strength, it is necessary to control such intermetallic compounds.

However, a dense and hard oxide film is formed on the surface of the aluminum alloy. In order to remove such a film, it is necessary to provide a large amount of heat during the joining operation. This may cause a problem that a thick intermetallic compound layer grows to lower the strength of the joint.

Therefore, when using a combination of such dissimilar metal materials, the dissimilar materials have conventionally been joined through mechanical fastening operations by bolts, rivets, and the like. However, this results in an increase in weight or cost. In the joining operation of such dissimilar metals, friction pressure bonding has been put into practical use in some parts. However, such frictional pressure welding operations are limited to joining of rotating bodies having good symmetry. Therefore, its use is quite limited. Bonding operations such as explosion bonding or hot rolling are widely known. However, these operations are problematic in terms of plant light efficiency, making it difficult to widely apply these operations to common dissimilar metals.

Japanese Patent Application Laid-open No. Hei 4-127973 discloses a method of performing resistance welding of a clad material made of the same two kinds of materials as those dissimilar metals between dissimilar metal materials to be joined with a current duration of 10 ms or less. In this way, the same materials are joined together.

However, in this method, three plates are required where two plates are required. In consideration of actual manufacture, cladding of the cladding material is required along with the insertion of the cladding material. In addition, new equipment must be assembled on existing welds, resulting in increased costs. Moreover, when joining aluminum and steel, since aluminum clad steel itself is manufactured by joining different materials mutually, manufacturing conditions become strict. Therefore, there is a problem that it is difficult to obtain an inexpensive clad material having stable performance.

Japanese Patent Application Laid-open No. Hei 6-39558 discloses that an aluminum alloy or pure aluminum having an Al content of 20 wt% or more is plated on the surface of the steel so as to have a thickness of 2 μm or more, and the steel and the aluminum material are brought into contact with each other to form such a plated surface. A material bonding method is disclosed in which an electric current is superimposed on an electric current, and a plating layer is preferentially melted and the steel side is hardly melted.

This aluminum plating operation requires a large amount of heat in order to break the rigid oxide film on the surface of the steel when joining the aluminum plating surface and the aluminum material. Thus, a weak intermetallic compound is formed at the interface between the aluminum plate and the steel, increasing the likelihood that the bonding will not occur.

When resistance welding three or more dissimilar materials, the dissimilar material interface and the same material interface may exist at the same time. When the resistance heat generation at the dissimilar material interface is smaller than the resistance heat generation at the same material interface, the nugget is formed at the same material interface due to the resistance heating difference, and almost no nugget is formed at the dissimilar material interface. In this case, in order to obtain sufficient bonding strength at each interface, it is necessary to provide sufficient heat for the nugget to have a desired diameter on the dissimilar material interface side. However, when the heat required to produce a sufficiently large nugget at the dissimilar material interface is provided, the resistance heat generation at the same material interface becomes excessive. Therefore, the resistance heat generation reduces the thickness of the low melting point side material, that is, the aluminum material side in the bonding example of the aluminum and steel.

In this specification, a method of joining dissimilar metal materials is disclosed. This method overlaps two or more sheets of first metal material and a plurality of plates of one or more sheets of second metal material having a lower melting point than the first metal material to form a dissimilar material interface and a homogeneous material interface, Forming a seam joint by resistance welding of which the contact resistance of the dissimilar material interface is lower than the contact resistance of the same material interface, energizing a first current through a plurality of overlapping sheet materials, and forming a nugget at the same material interface, 3 The nugget is formed at the dissimilar material interface by passing a second current larger than the first current through a plurality of overlapping plate members.

In addition, the present specification discloses a joining structure of dissimilar metal materials. Such a structure may include, for example, two or more plate layers of a first metal material, one or more plate layers of a second metal material having a lower melting point than the first metal material, a plate layer of a first metal material and a second metal. The dissimilar material interface between the plate material layers of the material and the dissimilar material interface between adjacent plate layers of the first metal material whose contact resistance of the dissimilar material interface is lower than the contact resistance of the dissimilar material interface, and formed at the dissimilar material interface and having a first diameter And a nugget formed at the interface of the same material and having a second diameter, wherein the first diameter is equal to or larger than the second diameter.

According to the joining method of the present invention, a desired nugget diameter can be formed at each interface while suppressing a decrease in the thickness of the low melting point side material, and the joint strength at each interface can be sufficiently secured. The present joining method can be used when three or more dissimilar metal materials are foam-joined by resistance welding. In addition, the present joining method can also be used in combinations of materials having the same material interface and the dissimilar material interface where the resistance heat generation of the dissimilar material interface becomes smaller than the resistance heat generation of the same material interface due to the difference in contact resistance of each interface. Moreover, the joining structure obtained by such a joining method is disclosed. This joining structure is, for example, a vehicle part such as a door, a hood, or the like.

The present invention will be described based on the following examples. However, the present invention is not limited to this embodiment.

The method for joining dissimilar metals according to the present invention relates to foam joining by resistance welding of three or more metal sheets having dissimilar material interfaces and homogeneous material interfaces. The contact resistance of the dissimilar material interface is smaller than the contact resistance of the same material interface. Specific combinations of such dissimilar metal materials may include, for example, steel-steel-aluminum alloy materials and steel-steel-magnesium alloy materials.

In the present invention, the term "same material" means a material having the same component system or the same metal structure. However, the term is not limited to those belonging to the same standard. For example, in the case of steel, even if it belongs to a separate standard such as carbon steel, alloy steel, mild steel, tensile strength steel and the like, it is regarded as a homogeneous material as long as it has a ferrite structure.

In the present invention, the term "homogenous material interface" means a bonding interface between homogeneous materials, and the term "heterogeneous material interface" means a bonding interface between different materials.

In one embodiment of the joining method for dissimilar metals, an AC power source type spot welding apparatus is used as shown in Fig. 1A. In FIG. 1A, foam welding is performed by pressing and energizing three sheets A, B, and C (B and C are the same material) by a pair of welding electrodes E1 and E2.

In this method of joining dissimilar metals, a relatively small first current is passed between superimposed materials to form a nugget at the same material interface, and then a second current larger than the first current is applied.

In the initial stage of the bonding, a relatively small current is energized, so that a nugget is formed at the same material interface having a large contact resistance and high resistance heat generation. In addition, when the same material interface is joined, electrical conduction is ensured and the resistance at the same material interface is lowered. In this manner, after the nugget is formed at the same material interface, resistance heat generation at the dissimilar material interface is sufficient, so that the desired nugget diameter can be formed at the dissimilar material interface.

At this time, as shown in Fig. 1B, the bonding can be performed while monitoring the contact resistance of the interface of the same material in the stacked sheet material. Bonding is performed by using a contact resistance monitoring device including an ammeter or a voltmeter for monitoring contact resistance and converting the first current into a larger second current in accordance with a change in resistance at the same material interface.

Although not shown, in FIG. 1B, the contact resistance between the plate A and the plate C may be monitored to allow the first current to be converted to the second current. Since the contact resistance between the plate B and the plate C is larger than the contact resistance between the plate A and the plate B, by monitoring the drop in the contact resistance between the plate A and the plate C the same The contact resistance at the reinterface may be lowered.

In addition to the contact resistance at the same material interface, the contact resistance at the dissimilar material interface can be monitored. When the contact resistance value of the same material interface becomes equal to the contact resistance value of the dissimilar material interface, the first current may be converted into a larger second current.

According to the bonding method of this embodiment, the resistance heating difference at the time of energization is reduced, so that the balance between the contact resistance of the dissimilar material interface and the same material interface is good. To achieve this, the surface roughness of at least one plate forming the dissimilar material interface can be made larger than the surface roughness of any plate surface forming the same material interface. Alternatively, the surface roughness of at least one plate forming the same material interface can be made finer than the surface roughness of any surface of the plate forming the dissimilar material interface.

For example, as a method of making a surface of a board | plate material rough, the operation | work which rubs with a scale with a rough scale, an etching operation, or a shot blasting operation can be performed. In addition, in order to improve the surface roughness (to make the surface fine and smooth), a grinding wheel polishing operation or a buff polishing operation can be considered as a finishing process.

In addition, for the same purpose, a material for increasing the electrical resistance can be interposed at the dissimilar material interface. More specifically, an alumina paste can be apply | coated to an interface, and carbon material, ceramics, an electrically conductive resin, etc. can be interposed.

In the bonding method taught herein, the sealing material may be interposed at the dissimilar material interface. The corrosion resistance of dissimilar materials can be improved by preventing the electrical corrosion resulting from the direct contact of dissimilar metals. In addition, resistance heat generation at the dissimilar material interface is promoted to increase the nugget diameter at the interface.

It is also possible to intervene at least one dissimilar metal material side forming the interface with the dissimilar material interface with a third metal material which is process melted or causes process melt. Thereby, even if a solid oxide film is formed on the bonding surface, such a coating can be easily discharged from the bonding interface.

2 is a binary state diagram of an aluminum-tin (Al-Zn) system as an example of an alloy in which a process reaction occurs. As shown in Fig. 2, in the Al-Zn system, the process point Te is 655K, and the process reaction occurs at a temperature much lower than the melting point of 933K of Al.

As described above, when the eutectic melting of Al and Zn occurs at the process point shown in Fig. 2 and the eutectic melting is used for the bonding action of the aluminum material such as oxide film removal or interdiffusion, low temperature bonding can be performed. Thereby, Fe 2 Al 5 or FeAl 3 Growth at the bonding interface of intermetallic compounds such as these can be effectively suppressed.

As used herein, process melting means melting using process reactions. When the composition of the mutual extension area | region which the two metals mutually spread | diffused is a process composition, when a holding temperature is more than process temperature, a liquid phase will form by process reaction. For example, for aluminum and zinc, the melting point of aluminum is 933K and the melting point of zinc is 692.5K. In addition, the process metal melts at 655 K below each melting point.

Therefore, when the clean surfaces of both metals are brought into contact with each other and kept heated at 655 K or more, a process melting reaction occurs. The process composition is Al-95% Zn. Although a solid oxide film exists on the surface of the aluminum material, this film is physically destroyed by energization and pressurization during resistance welding. That is, because the microscopic convex portions of the material surface come into contact with each other during pressurization, process melting occurs from portions of aluminum and zinc that are contacted by local breakdown of a portion of the oxide film. Since a liquid phase is formed, the oxide film around it is crushed and decomposed | disassembled. In addition, the reaction of the process melting is diffused to the entire surface to promote destruction of the oxide film and to achieve bonding through the liquid phase.

Since the process composition is automatically achieved by mutual diffusion, control of the composition is not necessary. There is a process reaction at the low melting point between the two metals or alloys. In the case of process melting of aluminum and zinc, when a Zn-Al alloy is used instead of zinc, it is advantageous if the composition contains 95% or more of zinc.

3 (a) to 3 (f) schematically show a bonding process using process melting in a state where a sealing material is interposed at a heterogeneous interface.

First, as shown in Fig. 3A, a galvanized steel sheet 2 and an aluminum alloy plate 1 are prepared. The galvanized layer 2p is provided on the galvanized steel sheet 2 and functions as a third metal material which causes a process with Al. The galvanized steel sheet 2 and the aluminum alloy plate 1 are stacked so that the galvanized layer 2p is adjacent to the aluminum alloy layer 1. Paste type seal material S is apply | coated to the interface, and the oxide film 1c is formed in the surface of the aluminum alloy layer 1.

Next, the to-be-joined material is pressed by a pair of upper and lower welding electrodes so that sealing material S may be discharged | emitted from the center part of a junction part to the outer peripheral part. In the central portion, the zinc plated layer 2p and the oxide film 1c on the surface of the aluminum alloy plate 1 directly contact each other.

As shown in Fig. 3C, when mechanical or thermal shock occurs by pressurization and energization, the oxide film is locally destroyed. As a result, as shown in Fig. 3D, when zinc and aluminum are locally contacted to maintain a temperature above the process point temperature of zinc and aluminum, eutectic melting of zinc and aluminum occurs.

As shown in Fig. 3 (e), by further pressing the electrode, impurities (not shown) of the oxide film 1c or the bonding interface together with the process molten metal are discharged around the junction with the sealing material. The predetermined joining area is secured. Thereafter, as shown in Fig. 3F, new surfaces of aluminum and steel are directly bonded to each other, whereby a solid metal joint can be obtained between the galvanized steel sheet 2 and the aluminum alloy plate 1.

The third metal material interposed between the two materials is not particularly limited as long as it is a material forming the aluminum alloy and the low melting point process. For example, the third metal material may include, in addition to zinc (Zn) mentioned above, copper (Cu), tin (Sn), silver (Ag), nickel (Ni), and the like.

This metal and Al generate a process reaction and melt at a temperature below the melting point of the base aluminum alloy material. Therefore, also in the joining of steel materials and aluminum alloy materials which are easy to form a weak intermetallic compound, an oxide film can be removed at low temperature. In addition, formation of the intermetallic compound at the bonding interface in the bonding process can be suppressed, and a firm bond is formed.

The material used to explain the process here is mainly a combination of steel and aluminum alloy, but a combination of steel and magnesium alloy may also be considered. When joining a steel material and a magnesium alloy material, the joining process can be performed by causing a process reaction between zinc and magnesium plated on the steel side.

The third metal material is not limited to the pure metal as described above. However, since the process metal also includes a binary alloy and a ternary alloy, the third metal material may include an alloy including at least one of these metals.

The third metal material may be interposed by any suitable method. One non-limiting example is the plating of a third metal material on the joining surface of one or more to-be-joined materials. It is contemplated that material insertion can be used if good or necessary. However, it can be understood that the plating process improves the working efficiency by reducing the number of manufacturing processes. No special preparation is required, and since commercially available galvanized steel for corrosion control can be used as it is, it is possible to easily and inexpensively perform solid joining of dissimilar metals.

The joining structure according to the joining method for dissimilar metals includes three or more dissimilar metal materials. When two or more sheets of the first metal material overlap with one or more sheets of the second metal material having a lower melting point than the first metal material, the dissimilar material interface and the homogeneous material interface are formed and the contact resistance of the dissimilar material interface is It becomes smaller than the contact resistance of the same material interface. In addition, a nugget having a diameter (Dd) in the range of 4.4√t1 <Dd <12√t1, preferably 5.5√t1 <Dd <12√t1 is formed at the dissimilar material interface to secure the strength required for the entire joint structure. can do. Here, t1 is the plate | board thickness of the one where the product of intensity | strength per unit area of each material which forms a dissimilar material interface, and plate | board thickness is smaller. Dd is the nugget diameter of the heterogeneous interface. Further, a nugget having a diameter Ds in the range of 4√t 2 <Ds <7√ t 2 is formed at the same material interface. t2 is the plate | board thickness of the one where the product of intensity | strength per sheet area and plate | board thickness of each material which forms the same material interface is smaller. Ds is the nugget diameter of the same material.

If the nugget diameter Dd at the dissimilar material interface and the nugget diameter Ds at the same material interface are respectively 4.4√t1 and 4√t2 or less, the bonding strength at each interface may be weak. If the nugget diameter Dd at the dissimilar material interface and the nugget diameter Ds at the same material interface are 12 √t1 and 7√t2 or more, respectively, more than necessary strength and a larger bond flanger width than necessary are formed. This can increase weight and cost.

EMBODIMENT OF THE INVENTION Hereinafter, this invention is demonstrated concretely based on an Example.

Next, the first embodiment shown in Figs. 4A and 4B will be described. As shown in Fig. 4A, a 6000 series aluminum alloy plate 1 having a plate thickness of 1.0 mm, a galvanized steel sheet 2 having a plate thickness of 0.8 mm, and a bare steel plate 3 having a plate thickness of 1.2 mm Bonding of three bundles nested in this order was performed. An R-type electrode having a radius of curvature of 40 mm in curvature of the tip was used as the electrodes E1 and E2 together with the spot welding apparatus of the AC power supply type provided with the contact resistance monitoring apparatus shown in FIG.

300 kgf while continuously monitoring the contact resistance of the same material interface with the monitoring device M, in order to form a nugget Ns at the same material interface, that is, the interface between the galvanized sheet 2 and the bare steel plate 3. The pressing force of was applied and the alternating current of 4000A was energized. When the contact resistance at the same material interface drops to a value of 20% of the initial contact resistance value previously measured and stored, the AC current is increased to 22000A. Then, an alternating current is energized for a total of 0.16 seconds. As shown in FIG. 4B, the nugget Nd is formed at the dissimilar material interface, that is, at the interface between the aluminum alloy plate 1 and the galvanized steel sheet 2.

By carrying out resistance welding in such an energization pattern, when the initial contact resistance difference is large, heat generation at the dissimilar material interface is suppressed. At the initial low current, heat generation is insufficient so that nuggets are not formed at the dissimilar material interface, while nugget Ns is formed at the same material interface. When the current is switched to a current larger than the initial low current, a portion of the same material interface is joined to lower the electrical resistance of the interface. Therefore, when suppressing heat generation at the same material interface, the nugget Nd may be formed at the dissimilar material interface.

Thus, while the thickness reduction of the aluminum alloy plate 1 by heat generation of the same material interface is suppressed, a favorable joint can be obtained by making the nugget diameter in both interfaces into an appropriate magnitude | size.

As a result, a nugget Ns having a diameter Ds = 5 mm is formed at the same material interface, and a nugget Nd having a diameter Dd = 7 mm is formed at the dissimilar material interface. Moreover, the discharge D which contains impurities, such as a molten process metal, an oxide film, a joining interface, is extruded around it.

In this embodiment, a galvanized steel sheet 2 is used. Therefore, the eutectic melting of zinc and aluminum as the third metal material works effectively. In this manner, the oxide film on the surface of the aluminum alloy plate 1 can be removed at a low temperature. This realizes contact between new faces of the dissimilar material interface, and a thin and uniform Fe-Al diffusion reaction layer (compound layer) is formed to obtain a high strength bonded joint.

In the second embodiment, as in the first embodiment, a 6000 series aluminum alloy plate 1 having a plate thickness of 1.0 mm, a galvanized steel sheet 2 having a plate thickness of 0.8 mm, and a bare steel plate having a plate thickness of 1.2 mm ( Bonding of 3 sheets of sheets 3) was carried out in this order. At this time, the surface of the aluminum alloy plate (1) forming the dissimilar material interface was polished by Emery No. 80 to roughen the surface of the galvanized steel sheet (2) and the bare steel plate (3) to form the same material interface. Thereby, the initial contact resistance of the dissimilar material interface was made to be equal to the contact resistance of the same material interface.

The same operation as above was repeated except that the initial current was set to 6000 A by using the spot welding apparatus shown in Fig. 1B. A nugget Ns having a diameter Ds = 5 mm was formed at the same material interface, and a nugget Nd having a diameter Dd = 8 mm was formed at the dissimilar material interface.

By roughening the surface of the dissimilar material interface, the contact resistance of the dissimilar material interface increases, and the resistance heat generation at the dissimilar material interface increases. This promotes the formation of the nugget at the dissimilar material interface. In addition, the thickness reduction of the aluminum alloy plate 1 due to the heat conduction of resistance heat generation at the same material interface is suppressed, and a nugget having an appropriate shape and size is formed. In addition, a good joint seam can be obtained in addition to the effect of eutectic melting.

The third embodiment is shown in Fig. 5A. Bonding of 3 sheets of 6000 series aluminum alloy plate 1 with a plate thickness of 1.0 mm, a galvanized steel sheet 2 with a plate thickness of 0.8 mm, and a bare steel plate 3 with a plate thickness of 1.2 mm were stacked in this order. It was. Moreover, the sealing material S which consists of an epoxy-type thermosetting resin was arrange | positioned at the interface of the aluminum alloy plate 1 and the galvanized steel plate 2.

The same operation as that of the first embodiment was repeated except that 450 kgf of pressing force was applied using the spot welding apparatus shown in FIG. A nugget Ns having a diameter Ds = 5 mm was formed at the same material interface, and a nugget Nd having a diameter Dd = 8 mm was formed at the dissimilar material interface.

Sealing material (S) is sandwiched between dissimilar materials to prevent electrical corrosion by direct contact between dissimilar materials. The resistance heat generation at the dissimilar material interface is increased by the electrical resistance of the seal material, thereby promoting the formation of a nugget at the dissimilar material interface. In addition, while the oxide film of aluminum is smoothly discharged from the bonding interface, a reduction in the thickness of the aluminum alloy plate 1 can be suppressed to obtain a good joint seam. A nugget having a shape and size appropriate for the dissimilar material interface and the same material interface is formed.

In the fourth embodiment, as in the first embodiment, a 6000 series aluminum alloy plate 1 having a plate thickness of 1.0 mm, a galvanized steel sheet 2 having a plate thickness of 0.8 mm, and a bare steel plate 3 having a plate thickness of 1.2 mm are used. ) Was bonded in a bundle of 3 sheets. At this time, in order to increase the contact resistance of the dissimilar material interface, a thin alumina paste was applied to the bonding surface of the aluminum alloy plate (1).

The same operation as in the first embodiment was repeated except that the initial current was 6000 A using the spot welding apparatus shown in FIG. 1B. A nugget Ns having a diameter Ds = 5 mm was formed at the same material interface, and a nugget Nd having a diameter Dd = 7 mm was formed at the dissimilar material interface.

In this embodiment, alumina is interposed at the dissimilar material interface, thereby increasing the electrical resistance between the aluminum alloy plate 1 and the galvanized steel sheet 2 together with the resistance heat generation. This promotes formation of the nugget at the interface. In addition, similarly to the respective embodiments, the oxide film can be smoothly discharged by the action of process melting based on the interposition of the galvanized layer 2p, and a good joint can be obtained.

To give an example of improved bonding of dissimilar materials, a first comparative example is described. Similarly to the first embodiment, a 6000 series aluminum alloy plate 1 having a sheet thickness of 1.0 mm, a galvanized steel sheet 2 having a plate thickness of 0.8 mm, and a bare steel sheet 3 having a plate thickness of 1.2 mm were stacked in this order. Three sheets of bonding were performed.

Bonding is carried out using the spot welding apparatus of the AC power supply type shown in Fig. 1A and the same electrodes E1 and E2 as described above, so that the nugget at the same material interface becomes an appropriate size. While applying a pressing force of 240 kgf, an alternating current of 12000 A was energized for 0.16 seconds.

As a result, a nugget Ns having a diameter Ds = 6 mm was formed at the same material interface, and a nugget Nd having a diameter Dd = 3 mm was formed at the dissimilar material interface.

For another comparison, a second comparative example is described. When carrying out a bundle of three sheets similar to the first comparative example, the same operations as the first comparative example were repeated except for the following points. An alternating current of 22000 A was energized for 0.16 seconds while applying a pressing force of 240 kgf so that the nugget at the dissimilar material interface was an appropriate size. This obtained the dissimilar metal bonding joint of this example.

As a result, a nugget Ns having a diameter Ds = 8 mm was formed at the same material interface. However, a nugget was formed in one end at the dissimilar material interface. As a result, a thickness decrease occurs in the aluminum alloy plate 1, and the aluminum alloy plate 1 is welded to the electrode E1. In addition, a hole was formed in the aluminum alloy plate 1, and a nugget suitable for the dissimilar material interface was not formed.

In the first to fourth examples, the first and second comparative examples, Table 1 shows a comparison result of the nugget formation state occurring at each interface and the thickness reduction state of the joined material.

As a result, in the first to fourth embodiments, the size of the nugget of the dissimilar material interface and the same material interface was appropriate, and thickness reduction did not occur. On the other hand, in the first comparative example, an appropriate nugget is formed at the same material interface, but a nugget of an appropriate size is not formed at the dissimilar material interface due to lack of heat generation. In addition, in the second comparative example, it was found that when sufficient current flows to form a nugget of an appropriate size at the dissimilar material interface, a thickness decrease occurs in the aluminum alloy plate, and a good joint can not be obtained.

division Material combination electric current
change
Creation state of the nugget thickness
Reduced state
Lee Jong-jae Interface Same material interface Comparative Example 1 6000 series Al alloy
Galvanized steel + bare steel sheet
none
(Small current)
small proper proper
2nd comparative example 6000 series Al alloy
Galvanized steel + bare steel sheet
none
(Large current)
- overabundance splendor
First embodiment 6000 series Al alloy
Galvanized steel + bare steel sheet
has exist proper proper proper
Second embodiment 6000 series Al alloy
Galvanized steel + bare steel sheet
(Al alloy roughening)
has exist proper proper proper
Third embodiment 6000 series Al alloy
Galvanized steel + bare steel sheet
(Sealing material placement)
has exist proper proper proper
Fourth embodiment 6000 series Al alloy
Galvanized steel + bare steel sheet
(Alumina Paste Application)
has exist proper proper proper

A fifth embodiment is shown in Fig. 6A. A bundle of three sheets of a 6000-based aluminum alloy plate 1 having a sheet thickness of 1.0 mm, a bare steel sheet 4 having a sheet thickness of 1.0 mm, and a bare steel sheet 3 having a sheet thickness of 1.2 mm were stacked in this order. .

Since the same operation is repeated as in the first embodiment, as shown in Fig. 6B, a nugget Ns having a diameter Ds = 5 mm is formed at the same material interface, and the diameter (at A nugget Nd with Dd) = 7 mm was formed.

As the steel material to be joined to the aluminum alloy plate 1, in this embodiment, a bare steel sheet 4 was used instead of the galvanized steel sheet 2. Therefore, process melting does not occur and removal of the oxide film on the surface of the aluminum alloy plate becomes difficult. For this reason, aluminum oxide remains in a nugget, and joining strength is slightly reduced.

A sixth embodiment is shown in Fig. 7A. 6000 series aluminum alloy plate 1 of 1.0 mm in thickness, hot dip galvanized steel sheet 2 of 0.8 mm in thickness, bare steel sheet 5 of 0.8 mm in thickness, and bare steel sheet of 1.2 mm in thickness (3) ) Was bonded in a bundle of four sheets.

Using a spot welding device shown in Fig. 1B, a pressing force of 450 kgf is applied, and a monitoring device M monitors the contact resistance at the same material interface, and first, an AC current of 4000 A is energized. Here, the contact resistance between the molten zinc steel sheet 2 and the bare steel sheet 3 is monitored. As in each embodiment, when the monitored resistance drops to a value of 20% of the initial contact resistance, the AC current is increased to 22000 A and energized for a total of 0.16 seconds.

As a result, as shown in FIG. 7B, a nugget Ns1 having a diameter Ds1 = 5 mm was formed at the same material interface of the galvanized steel sheet 2. Further, a nugget Ns2 having a diameter Ds2 = 5 mm was formed at the same material interface between the bare steel plate 5 and the bare steel plate 3. Further, a nugget Nd having a diameter Dd = 7 mm was formed at the dissimilar material interface composed of the aluminum alloy plate 1 and the galvanized steel sheet 2.

As described above, even in the case of four-sheet bonding, by using a galvanized steel sheet, the oxide thin film of aluminum is smoothly discharged from the bonding interface, and the thickness reduction of the aluminum alloy plate 1 is suppressed and the two same material interfaces are used. The nugget of a suitable shape and dimension was formed in the interface of the dissimilar materials, and a good joint was obtained.

The foregoing embodiments are described to facilitate understanding of the present invention and do not limit the present invention. On the contrary, the invention should be understood to cover various modifications and equivalents included within the scope of the appended claims, and should be construed broadly to include all such modifications and equivalents which are recognized under the law. .

1 (a) and (b) are each an overall view of a resistance welding device including an AC power supply type resistance welding device and a contact resistance monitoring device.

2 is a graph showing an Al-Zn based binary state diagram.

3 (a) to 3 (f) are schematic diagrams illustrating a bonding process using process melting in a state where a sealing material is interposed between dissimilar material interfaces.

4 (a) and 4 (b) are cross-sectional explanatory views showing the first, second and fourth embodiments of the three-sheet joining process.

5 (a) and 5 (b) are cross-sectional explanatory diagrams showing a third embodiment of a bonding process of a three-sheet bundle in which a sealing material is interposed between dissimilar material interfaces.

6 (a) and 6 (b) are cross-sectional explanatory diagrams showing a bonding process of three bundles using the bare steel plate of the fifth embodiment.

7 (a) and 7 (b) are cross-sectional explanatory views showing a sixth embodiment of a bonding process of a four-sheet bundle.

Claims (16)

  1. Is a joining method of dissimilar metal materials,
    Forming a dissimilar material interface and a homogeneous material interface by overlapping two or more sheets of first metal material and a plurality of plates of one or more sheets of second metal material having a lower melting point than the first metal material;
    Forming seam is formed by resistance welding in which the contact resistance of the dissimilar material interface is lower than the contact resistance of the same material interface,
    A nugget is formed at the same material interface by energizing a first current through a plurality of overlapping sheets of three or more sheets,
    A method of joining dissimilar metal materials, wherein a nugget is formed at a dissimilar material interface by passing a second current larger than the first current through three or more overlapping plate members.
  2. The method of claim 1, wherein the contact resistance at the same material interface is monitored while energizing the first current,
    The joining method of the dissimilar metal material which converts a 1st electric current into a 2nd electric current according to the fall of the contact resistance of the same material interface.
  3. 2. The surface roughness of at least one sheet of material of claim 1, wherein the surface of at least one sheet forming the dissimilar material interface is roughened before energizing the first current and the second current, and the surface roughness is at least one sheet forming the same material interface. Joining method of larger dissimilar metal materials.
  4. 2. The surface of at least one sheet of plate according to claim 1, wherein the surface of at least one sheet forming the same material interface is flattened before energizing the first current and the second current, and the roughness of the surface is the surface of the at least one sheet forming the dissimilar material interface. Joining method of dissimilar metal material finer than roughness.
  5. 2. The method of joining dissimilar metal materials according to claim 1, wherein a material for increasing the electrical resistance of the dissimilar material interface is interposed at the dissimilar material interface before energizing the first current and the second current.
  6. The method of joining dissimilar metal materials according to claim 1, wherein the sealing material is interposed between the dissimilar material interfaces before the first current and the second current are energized.
  7. The method of claim 1, wherein the first metal material is steel and the second metal material is aluminum alloy.
  8. The method of claim 1, wherein the first metal material is steel and the second metal material is a magnesium alloy.
  9. The joining method of a dissimilar metal material according to claim 1, wherein at least one sheet member forming a dissimilar material interface and a material in which process melting occurs are interposed at the dissimilar material interface before energizing the first current and the second current.
  10. 10. The method of joining dissimilar metal materials according to claim 9, wherein a sealing material is introduced between the interposed material and another plate forming a dissimilar material interface before energizing the first current and the second current.
  11. 7. The method of joining dissimilar metal materials according to claim 6, wherein the interposed material is a material plated on the surface of the first metal material forming the dissimilar material interface.
  12. 12. The method of claim 11, wherein the plated material is one or more of copper (Cu), tin (Sn), silver (Ag), nickel (Ni), and zinc (Zn).
  13. The joining structure of the dissimilar metal material obtained by the joining method of the dissimilar metal material of Claim 11.
  14. It is a joining structure of dissimilar metal materials,
    At least two plate layers of first metal material,
    At least one plate layer of a second metal material having a lower melting point than the first metal material,
    The dissimilar material interface between the plate layer of the first metal material and the plate layer of the second metal material,
    A homogeneous material interface between adjacent plate layers of the first metal material whose contact resistance of the dissimilar material interface is lower than that of the same material interface,
    A nugget formed at the dissimilar material interface and having a first diameter,
    A nugget formed at the same material interface and having a second diameter,
    The said 1st diameter is the joining structure of the dissimilar metal material more than the said 2nd diameter.
  15. The method of claim 14,
    The thickness of the at least two plate layers of the first metal material is t1, the thickness of the at least one plate layer of the second metal material is t2, and the first diameter Dd is in the range of 4.4√t1 <Dd <12√t1 And the second diameter Ds is a joining structure of dissimilar metal material in a range of 4√t2 <Ds <7√t2.
  16. A vehicle component comprising the joining structure of the dissimilar metal material according to claim 15.
KR1020080028895A 2007-03-30 2008-03-28 Bonding method of dissimilar materials made from metals and bonding structure thereof KR100983960B1 (en)

Priority Applications (4)

Application Number Priority Date Filing Date Title
JP2007092461 2007-03-30
JPJP-P-2007-00092461 2007-03-30
JPJP-P-2007-00307345 2007-11-28
JP2007307345A JP5376391B2 (en) 2007-03-30 2007-11-28 Dissimilar metal joining method and joining structure

Publications (2)

Publication Number Publication Date
KR20080089246A KR20080089246A (en) 2008-10-06
KR100983960B1 true KR100983960B1 (en) 2010-09-27

Family

ID=39994469

Family Applications (1)

Application Number Title Priority Date Filing Date
KR1020080028895A KR100983960B1 (en) 2007-03-30 2008-03-28 Bonding method of dissimilar materials made from metals and bonding structure thereof

Country Status (3)

Country Link
JP (1) JP5376391B2 (en)
KR (1) KR100983960B1 (en)
CN (1) CN101274387B (en)

Families Citing this family (18)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP5098792B2 (en) * 2008-05-09 2012-12-12 日産自動車株式会社 Dissimilar metal joining method of magnesium alloy and steel
JP5098804B2 (en) * 2008-05-21 2012-12-12 日産自動車株式会社 Dissimilar metal joining method and joining structure of magnesium alloy and steel
US20110261443A1 (en) 2008-10-23 2011-10-27 Mitsubishi Chemical Corporation Heat ray reflective film and laminate thereof, and coating fluid for forming heat ray reflective layer
JP5468350B2 (en) * 2009-10-23 2014-04-09 マツダ株式会社 Dissimilar metal plate joining method
CN101992342A (en) * 2010-10-26 2011-03-30 聂健 Double-pulse projection and spot welding process for blowdown nut of automobile metal fuel tank
JP5606884B2 (en) * 2010-11-25 2014-10-15 本田技研工業株式会社 Body seam welding structure
WO2012081521A1 (en) * 2010-12-15 2012-06-21 日産自動車株式会社 Bonding method and members to be bonded
CN102145439A (en) * 2011-04-29 2011-08-10 重庆理工大学 Method for carrying out heterogeneous resistance brazing on steel and aluminium alloy
DE102011109708A1 (en) * 2011-08-06 2013-02-07 Volkswagen Aktiengesellschaft Joining of sheet-like components with intermediate layer of thermoplastic material
JP6160190B2 (en) * 2013-04-15 2017-07-12 マツダ株式会社 Resistance spot welding method for dissimilar metal materials
CN103357999A (en) * 2013-07-27 2013-10-23 何强 Welding technique of electric resistance welding and stud welding of unmatched materials
DE102013108563A1 (en) * 2013-08-08 2015-02-12 Thyssenkrupp Steel Europe Ag Method and device for resistance welding of sandwich panels
US10166627B2 (en) 2013-10-04 2019-01-01 GM Global Technology Operations LLC Aluminum alloy to steel welding process
DE102013112436A1 (en) * 2013-11-12 2015-05-13 Thyssenkrupp Ag Multi-stage resistance welding of sandwich panels
DE102014115145A1 (en) * 2014-10-17 2016-04-21 Thyssenkrupp Ag Method and device for optimized resistance welding of metal sheets
US20180222150A1 (en) * 2017-02-06 2018-08-09 GM Global Technology Operations LLC Method for joining dissimilar metals and articles comprising the same
CN110475642A (en) * 2017-03-31 2019-11-19 杰富意钢铁株式会社 The manufacturing method of joint for resistance spot welding
CN109249118A (en) * 2018-08-21 2019-01-22 上海交通大学 Laminated plate based on electric resistance welding synchronizes compound two point progressive molding device and method

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR0171162B1 (en) * 1993-11-15 1999-02-18 미노루 다나까 Resistance welding method for steel plates and aluminum metal plates and material for resistance welding
KR20000062669A (en) * 1999-03-15 2000-10-25 제임스 이. 미러 Metal welding method and metal joining structure
JP2005305504A (en) 2004-04-21 2005-11-04 Kobe Steel Ltd Joined body of different materials of steel material and aluminum material and method for joining the same
KR20070004876A (en) * 2004-04-21 2007-01-09 가부시키가이샤 고베 세이코쇼 Joined body of dissimilar materials comprising steel material and aluminum material, and joining method therefor

Family Cites Families (15)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS6466076A (en) * 1987-09-03 1989-03-13 Nissan Shatai Co Joining structure for dissimilar metal
JPH0455066A (en) * 1990-06-25 1992-02-21 Kobe Steel Ltd Lap resistance welding method of aluminum material and steel material
US5302797A (en) 1991-08-30 1994-04-12 Sumitomo Metal Industries, Ltd. Resistance welding of aluminum
JPH0687079A (en) * 1992-09-09 1994-03-29 Nippon Steel Corp Butt welding method for resin clad steel sheet
US5783794A (en) 1993-11-15 1998-07-21 Nippon Steel Corporation Method and material for resistance welding steel-base metal sheet to aluminum-base metal sheet
JPH0957459A (en) * 1995-08-22 1997-03-04 Neox Lab:Kk Resistance-welding method for laminated damping plate
JP2000094141A (en) * 1998-09-17 2000-04-04 Fuji Electric Co Ltd Manufacture of vending machine
JP3797853B2 (en) * 2000-07-28 2006-07-19 独立行政法人科学技術振興機構 Method for producing aluminum alloy composite member by current bonding
JP3849508B2 (en) * 2001-11-30 2006-11-22 Jfeスチール株式会社 Spot welding method for high-tensile galvanized steel sheet
JP4469165B2 (en) * 2003-11-26 2010-05-26 株式会社神戸製鋼所 Dissimilar joints of steel and aluminum and their joining methods
JP4181063B2 (en) 2004-02-17 2008-11-12 日産自動車株式会社 Liquid phase diffusion bonding method for dissimilar metal sheets
JP4303629B2 (en) 2004-04-02 2009-07-29 日本プレーテック株式会社 Resistance welding method of different materials, aluminum alloy material, and resistance welding member of different materials
JP5120864B2 (en) * 2004-12-24 2013-01-16 日産自動車株式会社 Dissimilar materials joining method
JP4601052B2 (en) * 2004-12-24 2010-12-22 紘二郎 小林 Dissimilar metal joining method
JP5071752B2 (en) * 2005-05-24 2012-11-14 日産自動車株式会社 Dissimilar metal joining method by resistance seam welding

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR0171162B1 (en) * 1993-11-15 1999-02-18 미노루 다나까 Resistance welding method for steel plates and aluminum metal plates and material for resistance welding
KR20000062669A (en) * 1999-03-15 2000-10-25 제임스 이. 미러 Metal welding method and metal joining structure
JP2005305504A (en) 2004-04-21 2005-11-04 Kobe Steel Ltd Joined body of different materials of steel material and aluminum material and method for joining the same
KR20070004876A (en) * 2004-04-21 2007-01-09 가부시키가이샤 고베 세이코쇼 Joined body of dissimilar materials comprising steel material and aluminum material, and joining method therefor

Also Published As

Publication number Publication date
KR20080089246A (en) 2008-10-06
JP5376391B2 (en) 2013-12-25
CN101274387B (en) 2012-05-30
JP2008272825A (en) 2008-11-13
CN101274387A (en) 2008-10-01

Similar Documents

Publication Publication Date Title
JP5415896B2 (en) Indirect spot welding method
EP0865860B1 (en) Method of lap joining two kinds of metallic members having different melting points
CN101112740B (en) Method, structure and apparatus for bonding dissimilar metals
EP2314408B1 (en) Method of welding and adhesive bonding of dissimilar metal plates with pre-heating, cooling and welding steps; Dissimilar metal joined body
US5316863A (en) Self-brazing aluminum laminated structure
US20080063889A1 (en) Reactive Multilayer Joining WIth Improved Metallization Techniques
US8020749B2 (en) Dissimilar metal joining method
CN100522452C (en) Connecting method, connecting device and connecting structure of dissimilar materials
CA1266513A (en) Resistance welding of aluminium
US5599467A (en) Aluminum weldment and method of welding aluminum workpieces
JP4303629B2 (en) Resistance welding method of different materials, aluminum alloy material, and resistance welding member of different materials
JP6006805B2 (en) Method for joining dissimilar materials
US3121948A (en) Friction welding
US9174298B2 (en) Dissimilar metal joining method for magnesium alloy and steel
US8796580B2 (en) Processes for welding composite materials and articles therefrom
JP5014834B2 (en) MIG welding method for aluminum and steel
JP4601052B2 (en) Dissimilar metal joining method
WO1996022855A1 (en) Laser-assisted plating of strip
CN101918168B (en) Method of bonding different metals and bonded structure
EP0956195A1 (en) Aluminium sheet product and method of welding structural components
US8058584B2 (en) Bonding method of dissimilar materials made from metals and bonding structure thereof
DE10237763A1 (en) Process for the production of non-detachable cohesive connections from oxide-dispersed (ODS) -metallic materials or from components from oxide-dispersed- (ODS) -metallic materials by welding
DE102010013894A1 (en) Welding of light metal workpieces by reaction metallurgy
Atabaki et al. Welding of aluminum alloys to steels: an overview
CN102049591A (en) Dissimilar metal spot welding system of light metal and coated steel and welding method thereof

Legal Events

Date Code Title Description
A201 Request for examination
E902 Notification of reason for refusal
E701 Decision to grant or registration of patent right
GRNT Written decision to grant
FPAY Annual fee payment

Payment date: 20130819

Year of fee payment: 4

FPAY Annual fee payment

Payment date: 20140826

Year of fee payment: 5

FPAY Annual fee payment

Payment date: 20150819

Year of fee payment: 6

FPAY Annual fee payment

Payment date: 20160816

Year of fee payment: 7

FPAY Annual fee payment

Payment date: 20170818

Year of fee payment: 8

FPAY Annual fee payment

Payment date: 20180816

Year of fee payment: 9