JP2007330972A - Method, device and structure for joining dissimilar material - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a dissimilar material overlap-joining method capable of performing the high-strength joining without giving high heat input even when a dense oxide film is interposed between joining interfaces of materials formed by overlapping a high melting point material on a low melting point material, a joining device which is favorably used for joining the dissimilar materials, and a joining structure by this method. <P>SOLUTION: When a high melting point material 1 and a low melting point material 2 having melting points different from each other overlap and are joined with each other, both materials 1, 2 are heated by irradiating high energy beams on a surface of the high melting point material 1 while partially breaking an oxide film present on the joining interface. Both heated materials 1, 2 are relatively pressed against each other to continuously or intermittently joined with each other. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a technique for lap-joining dissimilar materials having different melting points such as steel materials and aluminum alloy materials, such as a high-energy beam obtained by superimposing high-energy beams such as electron beams and laser beams. A joining method of different materials, in which lap joining is performed by pressurizing both materials while irradiating the high melting point material side of a material to be joined made of a melting point material and a low melting point material, and a joining apparatus used for such joining Further, the present invention relates to a joining structure joined by such a method.

  Conventionally, in lap joining of dissimilar materials using a high energy beam such as an electron beam or a laser beam, a high-melting-point material is irradiated with a defocused high-energy beam in order to suppress the formation of brittle intermetallic compounds. However, the low melting point material side of the joining interface is melted and joined by heat transfer from the high melting point material side.

In general, when different materials are joined, if both materials are melted in the same manner as in the case of welding the same materials, a fragile intermetallic compound may be generated and sufficient joint strength may not be obtained.
For example, when different types of aluminum alloy and steel are joined, high hardness and brittle intermetallic compounds such as Fe ₂ Al ₅ and FeAl ₃ are generated. Therefore, in order to ensure joint strength, control of these metal compounds is required. Is required.

  However, a dense and strong oxide film is formed on the surface of the aluminum alloy, and in order to remove this, a large dose of heat is required at the time of joining. As a result, the intermetallic compound layer grows thick and has low strength. There is a problem that it becomes a new joint.

As described above, when joining different kinds of materials as described above, it is necessary to join while controlling the growth of the intermetallic compound with high precision. Therefore, precise temperature control is possible as an external heat source for heating. Attempts have been made to use high energy beams such as electron beams and laser beams.
In the lap joining of dissimilar materials using a high energy beam, in order to suppress the formation of brittle intermetallic compounds, a high energy beam defocused on the high melting point material side is irradiated to transmit from the high melting point material side. A method has been adopted in which a low melting point material is melted and joined by heat (for example, see Non-Patent Document 1).

In such a case, the welding conditions are controlled, only the material on one side (low melting point material) is melted at the joining interface, and the growth of the intermetallic compound layer is suppressed by joining using the diffusion of the material. It is considered that by reducing the thickness, the strength per unit area of the joint can be made higher than when both materials are melted and joined. A method is described in which a steel plate is stacked on an alloy and a laser beam is irradiated from above the steel plate to join different materials with the interface in a solid phase / liquid phase state.
“Overview of the National Conference of the Japan Welding Society”, Japan Welding Society, April 2003, Vol. 72, p. 152

However, as described above, when the amount of heat input increases in joining different types of materials, a high hardness and brittle intermetallic compound is generated at the joining interface, and high joint strength cannot be obtained. On the other hand, a dense and strong oxide film is formed on the surface of the aluminum alloy. Even in the method described in Non-Patent Document 1 in which only the material on one side is melted, in order to remove the oxide film, a large amount is required at the time of joining. Since the amount of input heat is required, a thick intermetallic compound layer is likely to grow and become a low-strength joint.
Therefore, in order to control the production of intermetallic compounds at the bonding interface and obtain good bonding strength, the bonding conditions must be controlled very precisely, and the appropriate bonding condition range is extremely narrow. Even if a high-energy beam whose condition control is relatively easy is used as a heat source, there is a problem that it is extremely difficult to put it to practical use industrially.

  The present invention has been made in view of the above-mentioned problems in conventional dissimilar material bonding technology using a high-energy beam, and the object of the present invention is that even if a dense oxide film is present at the bonding interface. , A bonding method of different materials capable of high strength bonding without applying large heat input, a bonding apparatus that can be suitably used for bonding such different materials, and a bonding structure by such a method It is to provide.

  As a result of intensive studies to achieve the above object, the present inventors have partially destroyed the oxide film on the bonding interface when irradiating the high melting point material of the superimposed material to be bonded with a high energy beam. As a result, a diffusion reaction of both materials starting from this occurs, and the above-mentioned object can be solved, and the present invention has been completed.

That is, the present invention is based on the above knowledge, and in the bonding method of dissimilar materials according to the present invention, when a high melting point material and a low melting point material having different melting points are bonded to each other, While partially destroying the film, the surface of the refractory material is irradiated with a high energy beam to heat both materials, and both heated materials are relatively pressurized to join both materials continuously or intermittently. I am doing so.
Further, as a preferred embodiment of the bonding method, at least one of the two panels and the third material are irradiated by irradiating a high energy beam with a third material different from these materials interposed between the two materials. It is characterized in that eutectic melting occurs between the materials and bonding.

  The dissimilar material bonding apparatus of the present invention is disposed so as to be relatively movable with respect to the material to be bonded, and continuously applies a high energy beam to the bonded portion of the material to be bonded while continuously or intermittently moving relative thereto. Or the irradiation head which irradiates intermittently, the film destruction means which is arrange | positioned ahead of the advancing direction of the irradiation position of the high energy beam by this irradiation head, and destroys the oxide film of a joining interface partially, and progress of the said irradiation position It is provided with a pressurizing means that is disposed rearward in the direction and pressurizes the heating unit by high energy beam irradiation.

  The dissimilar material joining structure of the present invention is obtained by a joining method according to a preferred embodiment performed in a state where a third material is interposed between both panels, and includes a low melting point material and a high melting point material. The new surfaces are joined directly or via a reaction layer of at least one of the two panels and the third material, and the third material, the panel-derived component, the oxide film, and the joint are formed on both sides of the joint. Emissions comprising at least one selected from the group of reaction products generated in the process are discharged.

  According to the present invention, the surface of the high melting point material is irradiated with a high energy beam while partially destroying the oxide film present at the joining interface of the material to be joined, which is a superposition of the low melting point material and the high melting point material. Since both materials are heated and the heated materials are relatively pressurized and joined together, even when irradiated with a high-energy beam with a reduced amount of input heat, both parts start from the broken portion of the oxide film. The diffusion reaction of the material can be advanced, the growth of the intermetallic compound layer can be suppressed, and a high strength dissimilar joint can be obtained.

  Hereinafter, the bonding method and bonding apparatus for different materials of the present invention will be described in more detail and specifically.

In the method for bonding dissimilar materials according to the present invention, as described above, the dissimilar materials are overlap-bonded by irradiating a high-energy beam on the high melting point material side of the material to be bonded formed by stacking dissimilar materials having different melting points. When performing, the oxide film formed on the bonding interface of the materials to be bonded is partially broken.
In other words, since the oxide film at the bonding interface is partially destroyed in advance, the diffusion reaction of both materials easily starts from the broken part of this oxide film, so the amount of heat applied by the high energy beam can be suppressed. This makes it possible to perform high-strength bonding while suppressing the formation of intermetallic compounds.

  Further, in the bonding apparatus for dissimilar materials according to the present invention, as described above, the dissimilar material is disposed so as to be relatively movable with respect to the material to be bonded formed by superimposing the high melting point material and the low melting point material, and continuously or intermittently. An irradiation head that irradiates a high energy beam continuously or intermittently to the bonded portion of the material to be bonded while moving relative to each other, and is located in the front of the traveling direction of the irradiation position of the high energy beam by this irradiation head and exists at the bonding interface The method for joining according to the present invention comprises: a film breaking means for partially breaking an oxide film to be applied; and a pressure means for pressurizing a heating portion by beam irradiation disposed behind the beam irradiation position in the traveling direction. Can be suitably used.

  FIGS. 1A and 1B are a side view and a front view, respectively, showing an example of a dissimilar material joining apparatus used in the present invention and a different material lap joint procedure using the joining apparatus. A bonding apparatus 10 shown is an irradiation head 11 that irradiates a YAG laser that is one kind of high-energy beam, a pressurizing roller (film breaking means) 12 that is disposed on the front side in the traveling direction, and a rear side in the traveling direction. The pressure roller (pressure means) 13 is mainly configured.

The irradiation head 11 is connected to a laser oscillator via an optical fiber (not shown), and a laser beam B whose focus position is arbitrarily adjusted from the tip thereof is joined by superimposing the high melting point material 1 and the low melting point material 2. It is possible to irradiate the material at an arbitrary angle.
FIG. 1B shows the positional relationship of the preload roller 12 and the pressure roller 13 as viewed from the traveling direction of the laser beam B. The preloading rollers 12 and 12 are aligned on the same straight line along the traveling direction. In order to avoid interference with the pressure roller 13, the laser beam B is irradiated at a predetermined angle.

On the other hand, the pre-loading roller 12 and the pressure roller 13 are attached to the apparatus substrate 14 via guides 12a and 13a each incorporating an air cylinder, and the roller is adjusted by adjusting the pressure of air supplied to these air cylinders. The pressing force against the material of the part can be controlled.
Further, the preload roller 12 and the pressure roller 13 move integrally with the irradiation head 11 so that the preload roller 12 and the pressure roller 13 can always move while pressing the material to be joined at a certain distance from the laser beam B. The work (material to be joined) is not a flat surface, and can follow a three-dimensional shape such as an automobile body.

In the bonding apparatus 10 having such a structure, continuous linear bonding can be performed by continuously moving and irradiating a laser beam, and dot-like by intermittently moving and moving the irradiation. (Spot) or intermittent straight (stitch) -like joining can be performed.
In addition, the said joining apparatus 10 may be made to move with respect to the fixed to-be-joined material, or the side of the to-be-joined material may be moved by fixing the joining apparatus 10 side.

  In the figure, as a material to be joined, for example, an aluminum alloy material 2 can be used as a low melting point material, and a galvanized steel sheet 1 that is a high melting point material is superimposed on the material with a slight gap that can normally occur. .

Here, when the aluminum alloy material 2 and the galvanized steel sheet 1 are relatively closely adhered while being plastically deformed by the preloading roller 12 which is a film breaking means, as shown in FIG. When the two are pressed against each other, the oxide film 2c on the surface of the aluminum alloy material 2 is thin and has low ductility.
Following this, the laser beam B is focused on the side of the galvanized steel sheet 1 which is a high melting point material so that the focal point is focused in front of the material surface, that is, defocused, and the steel sheet 1 which is a high melting point material is melted at the joining interface. After irradiating under such conditions, a predetermined pressing force is applied to the heated portion by the beam irradiation by the pressure roller 13 so that the aluminum alloy material 2 and the galvanized steel sheet 1 are relatively brought into close contact with each other.

  As a result, the temperature at the interface of the aluminum alloy material 2 rises due to heat transfer from the high-temperature galvanized steel sheet 1, and zinc (1p) at the bonding interface and other compounds are discharged by the pressure applied by the pressure roller 13. Starting from the film breaking portion 3, the irradiation conditions of the laser beam B and the moving speed of the preload roller 12 and the pressure roller 13 are controlled precisely so that the intermetallic compound of aluminum and steel is formed thinly and uniformly. As a result, the dissimilar materials 1 and 2 can be joined.

In the method for bonding dissimilar materials according to the present invention, the high energy beam is irradiated while being relatively moved with respect to both materials (materials to be joined), and the film breaking means is disposed in front of the irradiation direction of the high energy beam In addition to destroying the oxide film, the two materials can be joined by pressurizing them with a pressurizing means disposed behind the high energy beam irradiation position in the traveling direction.
At this time, continuous linear bonding is possible by making relative movement of the high energy beam to the material to be joined and irradiation of the high energy beam continuous, which is suitable for improving the rigidity and strength of the vehicle body. While linear linear joining can be realized with high productivity, spot-like or stitch-like joining can be performed if the relative movement and irradiation timing of the high energy beam are made intermittent.

  As the film destruction means, for example, a pressurizing roller can be adopted, and by pressing the both materials relatively with each other prior to the irradiation of the high energy beam by this pressurizing roller, a complicated three-dimensional The oxide film can be reliably destroyed by following the curved surface easily.

  In addition, it is also desirable to form an uneven shape on the pressing surface of the pressure roller (the pressure contact surface with both materials), which promotes the generation of minute contact portions at the joining interface and more reliably prevents the oxide film from forming. As partial breakage progresses and the uneven pattern of the preload roller is transferred to the surface of the material to be joined, the beam absorption rate at the time of irradiation with the high energy beam immediately after that improves, and the heat input is lower. This enables precise beam irradiation and improves energy efficiency.

  As the film breaking means, a single means for giving mechanical deformation, temperature change, ultrasonic vibration, thermal shock or electric shock, or a composite means for giving a combination of two or more of these can be adopted. When local destruction of the oxide film at the bonding interface is performed before the energy beam irradiation, partial destruction of the oxide film can be ensured according to various cases.

  Further, in the bonding method of different materials of the present invention, a third material different from these materials is interposed between the high melting point material and the low melting point material, and in this state, the surface of the high melting point material is irradiated with the high energy beam. In addition, it is possible to cause eutectic melting between at least one of the two materials and the third material so as to bond both materials, thereby removing the oxide film from the bonding interface at a low temperature. It is possible to prevent the rise of the bonding interface temperature, suppress the formation of intermetallic compounds, and more easily and firmly bond the new surfaces of the materials to be bonded to each other under a wider range of conditions. become.

  At this time, as a specific means for interposing the third material between the two panels, it is desirable to plate the third material on at least one of the panels to be joined. The process of sandwiching the above material as an insert material between the panels can be omitted, and not only the work efficiency is improved by reducing the processing man-hours, but also the plating layer melted by the eutectic reaction together with the surface impurities around the joints. After being discharged, an extremely clean new surface appears from under the plating layer, and a stronger bond is possible.

When one of the materials to be joined is a steel material, for example, use a galvanized steel sheet in which zinc, which is a third material that forms a low melting point eutectic with aluminum or magnesium, is plated on the surface in advance. Is desirable.
By using such galvanized steel sheets, it is possible to apply ordinary commercial steel materials that have been galvanized for the purpose of rust prevention without applying new plating or requiring special preparation. In addition, it is possible to perform strong bonding with the above-described dissimilar materials extremely simply and inexpensively.

Here, eutectic melting will be described by taking an Al—Zn alloy as an example.
FIG. 3 shows an Al—Zn-based binary phase diagram. As shown in the figure, the eutectic point (Te) in the Al—Zn system is 655 K, which is much lower than the melting point 933 K of Al. A eutectic reaction occurs at temperature.
Therefore, by using the eutectic points shown in the figure to create eutectic melting of Al and Zn, and using them for bonding actions such as oxide film removal and interdiffusion during bonding of aluminum materials, low temperature bonding can be performed. Therefore, the growth of the intermetallic compound at the bonding interface can be suppressed extremely effectively.

Here, eutectic melting means melting utilizing a eutectic reaction, and when the composition of an interdiffusion region formed by mutual diffusion of two metals (or alloys) becomes a eutectic composition, a holding temperature. If is equal to or higher than the eutectic temperature, a liquid phase is formed by the eutectic reaction. For example, in the case of aluminum and zinc, the melting point of aluminum is 933 K and the melting point of zinc is 692.5 K, whereas this eutectic metal melts at 655 K, which is lower than the respective melting points.
Therefore, a reaction occurs when the clean surfaces of both metals are brought into contact and heated to 655K or higher. This is called eutectic melting, and Al-95% Zn has a eutectic composition, but the eutectic reaction itself is a constant change unrelated to the alloy components, and the alloy composition only increases or decreases the amount of eutectic reaction. Absent.

On the other hand, although an oxide film exists on the surface of the aluminum material, in the present invention, prior to the irradiation with the high energy beam, a part of the oxide film is locally localized by the film breaking means such as the pressurizing roller described above. To destroy.
That is, local contact between zinc and aluminum occurs due to partial destruction of the oxide film, and in this state, the surface of the galvanized steel sheet is heated by irradiation with a high energy beam, and the bonding interface is maintained at a predetermined temperature state. Then, eutectic melting occurs from the contact area, and by the formation of this liquid phase, the nearby oxide film is crushed and decomposed, and further eutectic melting spreads over the entire surface. Joining is achieved.

  Since the eutectic composition is spontaneously achieved by interdiffusion, composition control is not necessary. The essential condition is that a low melting eutectic reaction exists between two metals or alloys. In the case of eutectic melting of aluminum and zinc, when using a Zn-Al alloy instead of zinc, The composition must be at least 95% zinc.

FIGS. 4A to 4E are schematic views showing an example of joining a galvanized steel sheet (high melting point material) and an aluminum alloy material (low melting point material) as a joining process of different materials according to the present invention.
First, as shown in FIG. 4A, a galvanized steel sheet 1 provided with a galvanized layer 1p functioning as a third metal material that forms a eutectic with Al on at least the surface on the bonding interface side, and aluminum An alloy material 2 is prepared. An oxide film 2 c is generated on the surface of the aluminum alloy material 2.

Next, as shown in FIG. 4 (b), the galvanized steel sheet 1 and the aluminum alloy material 2 are overlapped so that the galvanized layer 1p is on the inside, and relatively pressed by a film breaking means, for example, a pressure roller. .
Then, depending on the deformation caused by the pressing and the type of the film destruction means, the oxide film is locally broken as shown in FIG. 4C due to mechanical, thermal, or electrical impact.

  As a result, local contact between zinc and aluminum occurs, the surface of the galvanized steel sheet 1 is heated by irradiation with a high energy beam, and the bonding interface is maintained at a predetermined temperature state. As shown, eutectic melting of zinc and aluminum occurs.

  Then, the discharge comprising the oxide film 2c and impurities (not shown) at the bonding interface together with the eutectic molten metal 4 is discharged to the outside (in the direction of the arrow) of the bonding portion by pressurization, whereby a predetermined bonding area is obtained. As a result, as shown in FIG. 4 (e), the new surfaces of the aluminum alloy material and the steel material are directly joined by the extremely thin reaction layer 5, and a strong metal joint between the steel plate 1 and the aluminum alloy material 2 is obtained. It will be different. A thin diffusion layer of zinc to the steel may be formed between the reaction layer 5 and the steel material 1 depending on the material and joining conditions, but there is little influence on the joining strength and there is no substantial problem.

As a specific combination of the materials to be joined in the method for joining different types of materials of the present invention, for example, a combination of a steel material and an aluminum alloy material can be mentioned, and at this time, as a third material interposed between both materials, The material is not particularly limited as long as it is a material that forms a low melting point eutectic with an aluminum alloy. For example, zinc (Zn), copper (Cu), tin (Sn), silver (Ag), nickel (Ni) Etc. can be used.
That is, the eutectic metal of these metals and Al melts below the melting point of the aluminum alloy material, which is the base material, so that even when joining steel materials and aluminum alloy materials where fragile intermetallic compounds are easily formed, oxidation occurs at a low temperature. The film can be removed, the formation of intermetallic compounds at the bonding interface during the bonding process can be suppressed, and strong bonding becomes possible.

Moreover, when considering the application of the joining method of the present invention to the assembly of an automobile body, the material of the panel to be joined is mostly a combination of steel and aluminum, but in the future, steel and magnesium or aluminum A combination with magnesium is also conceivable.
When joining the steel panel and magnesium, it is possible to cause a eutectic reaction between zinc and magnesium plated on the steel side in the same manner as in the examples described later. Furthermore, even when aluminum and magnesium are joined, zinc or silver can be used as the third material.

  In the present invention, the third material is not necessarily limited to the pure metal as described above, and eutectic metal includes both binary alloys and ternary alloys. Therefore, at least one of these metals is used. An alloy containing may be used.

  The joint structure of different materials of the present invention is obtained by interposing the third material between the low melting point material and the high melting point material as described above, and the new surfaces of both panels are directly or both It is joined via a reaction layer of at least one of the panels and the third material, and on both sides of this joint, the third material, components derived from both materials, oxide film, reaction products at the time of joining, etc. Since it has a structure in which the discharged matter is discharged, it is possible to stably exhibit high bonding strength. For example, a light alloy material such as an aluminum alloy or a magnesium alloy is used as the low melting point material. By using a galvanized steel sheet as the melting point material, it can be suitably used for a lightweight vehicle body member for automobiles.

  Hereinafter, the present invention will be specifically described based on examples.

Example 1
As shown in FIG. 1, a galvanized steel sheet 1 (high melting point material) having a thickness of 0.55 mm is layered on an A6000 series aluminum alloy material 2 (low melting point material) having a thickness of 1.0 mm. The laser beam B by YAG laser was irradiated from the side of a certain steel plate 1.
At this time, the laser beam B is pressed by the preloading roller 12 as the film breaking means in front of the laser beam B, and the pressure roller 13 as the pressing means is pressed behind the laser beam B, respectively. The pressure roller 13 was continuously joined linearly by moving the pressure roller 13 in the direction indicated by the arrow in the figure.

  The irradiation condition of the laser beam B is such that the plating layer 1p at the bonding interface is irradiated in a range where zinc does not evaporate, that is, below the boiling point of zinc, and aluminum is transferred by heat transfer from the high-temperature galvanized steel sheet 1. The movement speed of the laser beam B, the preloading roller 12 and the pressure roller 13 is controlled so that the interface temperature of the alloy material 2 rises and becomes equal to or higher than the eutectic temperature of aluminum and zinc (655 K or higher, see FIG. 3). Welding was performed.

Specifically, using a YAG laser oscillator with a maximum output of 3 kW and a lens with a focal length of 150 mm, the beam is defocused so that the spot diameter is 3.5 mm on the surface of the galvanized steel sheet, the YAG laser output is 1.0 kW, and the moving speed is The bonding was performed at 1.0 m / min, with the pressure applied by the preload roller 12 and the pressure roller being 100 MPa.
Further, during laser irradiation, shielding was performed by flowing argon gas at a flow rate of 25 L / min with a nozzle coaxial with the laser.

  As a result of cutting out a macro test piece from the obtained bonded body and observing the macro structure of the bonded portion, the new surfaces of the aluminum alloy and the steel material are directly bonded to each other, and reaction products such as oxide film and eutectic molten metal are formed on both sides thereof. It was confirmed that a good joining structure in which exhausted materials such as the above were discharged was obtained.

In this embodiment, the preload roller 12 and the pressure roller 13 are pressed from one side and the joint is joined while pressing the joint. However, when the lower material is low in rigidity or when the flange is welded, etc. In addition, it is desirable that the preload roller and the pressure roller each have a pair of upper and lower sides, and that bonding be performed while pressing the material to be bonded from both sides as necessary.
For example, the lower roller is moved in a state of being drawn toward the upper roller, the material is sandwiched between the upper roller and the joint is pressed. By making the structure of the roller in this way, as described above, it is possible to cope with the case where the lower material is not rigid or when the flange is joined.

  FIG. 5 shows an example of the shape of the outer peripheral portion of the preload roller 12. For example, as shown in FIG. 5A, the outer surface of the pressurizing roller 12, that is, the pressing surface 12 b pressed against the surface of the material to be joined. By forming the concavo-convex portion 12c by knurling or forming the concavo-convex groove 12d by notch processing as shown in FIG. 5B, by using the preload roller 12 having such a shape, As shown in FIG. 2, local destruction of the oxide film on the surface of the aluminum alloy material due to the pressing of the microscopic irregularities at the joining interface can be more reliably caused in a wide range.

(Example 2)
FIG. 6 shows an example in which pulse energization is used instead of the above-described pressurizing roller as the film breaking means.

As shown in the figure, similarly, a galvanized steel sheet 1 is superimposed on an aluminum alloy material 2, and the defocused laser beam B is irradiated to the galvanized steel sheet 1 side.
Immediately before that, a pair of upper and lower electrodes 15, 15 formed in a roller shape from a highly conductive metal material such as a copper alloy are pressed between the electrodes 1, 15 while relatively pressing both materials 1, 2. The pulse energization is performed.

Immediately after the laser beam B, a predetermined pressing force is applied by a pair of pressure rollers 13 and 13 so that the aluminum alloy material 2 and the galvanized steel sheet 1 are relatively closely bonded to each other.
A pair of upper and lower electrodes 15 and 15 are connected to a power source 17 through a transformer 16. Through the electrodes 15 and 15, both materials 1 and 2 are energized for a short time, that is, pulse energization. As a result, the oxide film at the joint interface between the aluminum alloy material 2 and the galvanized steel sheet 1 can be efficiently and locally destroyed, and the same effect as in the above-described embodiment can be obtained.

(Example 3)
FIG. 7 shows an example in which ultrasonic vibration is applied as the film breaking means. FIG. 7A is a front view of the joining apparatus as seen from the traveling direction, and FIG. Is a side view of the same, and a laser beam B defocused on the galvanized steel sheet 1 side similarly is applied to the material to be joined in which the aluminum alloy material 2 and the galvanized steel sheet 1 are overlapped.

Immediately before the laser beam irradiation position, ultrasonic vibration is applied in the direction of the arrow while relatively pressing both materials 1 and 2 by the vibration roller 19 and the lower roller 20 connected to the ultrasonic generator 18.
Further, immediately after the beam irradiation position, a predetermined pressing force is applied by a pair of pressure rollers 13, 13, whereby the aluminum alloy material 2 and the galvanized steel sheet 1 are relatively closely bonded to each other.

  In this way, by applying ultrasonic vibration while applying relative pressure to both materials 1 and 2 via the vibration roller 19 connected to the ultrasonic generator 18 and the lower roller 20, the aluminum alloy material 2 and the galvanized steel sheet 1 can be locally destroyed at the bonding interface, and the same effects as in the above embodiment can be obtained.

As described above, the lap joining method, apparatus, and joining structure of the aluminum alloy material and the steel material have been described through the examples. However, the present invention is not limited to these examples, and does not depart from the gist of the present invention. Various modifications can be made within.
For example, in the above-described embodiment, an example in which a YAG laser is used as a heat source for heating has been described. However, the present invention is not limited to this, and a precise control capable of inducing a eutectic reaction and controlling the reaction is possible. Any high-energy beam can be used. Further, a heating heat source such as a laser beam can be continuously irradiated to perform continuous linear bonding, or can be irradiated intermittently and linearly bonded to stitches.

It is the front view (a) and side view (b) which show one Example of the joining apparatus of this invention. It is sectional explanatory drawing which shows typically the microstructure of the joining interface in the joining method of this invention. It is a graph which shows the eutectic point in an Al-Zn type binary phase diagram. (A)-(e) is process drawing which shows roughly the joining process of the dissimilar material which interposed the 3rd material. (A) And (b) is explanatory drawing which shows the example of the outer periphery shape of the pressurization roller used for this invention. It is a side view which shows the joining apparatus used for the 2nd Example of this invention, and the joining procedure by it. It is a side view which shows the joining apparatus used for the 3rd Example of this invention, and the joining procedure by it.

Explanation of symbols

1 Galvanized steel sheet (high melting point material)
1p Zinc plating layer (third material)
2 Aluminum alloy material (low melting point material)
2c Oxide film 4 Eutectic molten metal 5 Reaction layer 10 Dissimilar material joining device 11 Irradiation head 12 Pressure roller (film breaking means)
12b Press surface 12c, 12d Concavity and convexity 13 Pressure roller (pressure means)
15 Electrode (film destruction means)
19 Vibrating roller (film destruction means)

Claims (10)

  When superimposing and bonding a high melting point material and a low melting point material having different melting points, the surface of the high melting point material is irradiated with a high energy beam while partially destroying the oxide film at the bonding interface, and both materials are heated. A method for joining dissimilar materials, characterized in that both heated materials are relatively pressurized to join both materials continuously or intermittently.   The high energy beam is irradiated while being relatively moved with respect to both materials, and the oxide film is destroyed by the film breaking means disposed in front of the high energy beam irradiation position in the traveling direction, and at the rear of the irradiation position in the traveling direction. The method for joining different materials according to claim 1, wherein both materials are pressurized by an arranged pressurizing means.   3. The method for joining different materials according to claim 2, wherein the film breaking means is a pressurizing roller that relatively presses both materials.   4. The method for joining different materials according to claim 3, wherein unevenness is formed on the pressing surface of the pressurizing roller.   3. The dissimilar material according to claim 2, wherein the film breaking means is means for applying at least one selected from the group consisting of mechanical deformation, temperature change, ultrasonic vibration, thermal shock, and electric shock. Joining method.   In a state where a third material different from these materials is interposed between the high melting point material and the low melting point material, a high energy beam is irradiated, so that at least one of the two materials and the third material are shared. The method for joining different materials according to any one of claims 1 to 5, wherein the joining is performed by causing crystal melting.   The method for joining different types of materials according to claim 6, wherein at least one of the two materials is plated with a third material.   8. The method of joining different materials according to claim 7, wherein one of the two materials is a galvanized steel sheet, and zinc plated on the galvanized steel sheet is used as the third material. An irradiation head that is disposed so as to be relatively movable with respect to the material to be bonded, and continuously or intermittently irradiates a high energy beam to a bonded portion of the material to be bonded while being relatively moved relative to the material to be bonded;
A film breaking means disposed in front of the traveling direction of the high energy beam irradiation position by the irradiation head and partially destroying the oxide film at the bonding interface;
An apparatus for joining different kinds of materials, comprising a pressurizing unit disposed behind the high energy beam irradiation position in the traveling direction and pressurizing a heating part by high energy beam irradiation.   It is a joining structure obtained by the joining method according to any one of claims 6 to 8, wherein the new surfaces of the two materials are directly or the reaction layer of at least one of the two materials and the third material. At the same time, on both sides of the joint, there is an emission comprising at least one selected from the group of the third material, the material to be joined, the oxide film, and the reaction product generated in the joining process. Dissimilar material joint structure characterized by being discharged.

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