JP4374526B2 - Method and apparatus for joining different materials - Google Patents

Description

  The present invention relates to a bonding method and a bonding apparatus for different materials used for overlapping and bonding two different kinds of materials.

  When two different types of materials are joined, if both materials are melted in the same manner as when joining the same type of materials, a brittle intermetallic compound is produced, and sufficient joint strength can be obtained. Can not.

  Therefore, by controlling the welding conditions and melting only one material at the joint interface and joining using the diffusion of the material, the thickness of the intermetallic compound layer can be reduced. It is possible to increase the strength per unit area of the joined portion as compared with the case of melting.

  A high energy beam such as a laser is suitable for the case where only one of the materials is desired to be melted because it is easy to finely control the welding conditions. Conventionally, when two kinds of different materials are joined together by a high energy beam. In order to suppress the formation of brittle intermetallic compounds, a method has been adopted in which the material is diffused and bonded by simply controlling the processing conditions of the high energy beam and melting only one of the materials.

JP 2001-252777 A

  However, the thickness of the intermetallic compound layer that affects the joint strength described above varies depending on the temperature and pressure of the joint portion, and in order to achieve good diffusion, pressure at the joint interface is necessary, and the heat source When a high energy beam such as a laser is used, the temperature can be controlled but the pressure cannot be controlled.

  When bonding is performed by irradiating a high energy beam without applying pressure to the bonding part, the beam irradiation condition range in which good diffusion is performed is very narrow, and the part where the temperature and pressure are favorable at the bonding interface Since the area of the joint is also narrow, the joint width is also narrowed, and welding with a high-energy beam is non-contact welding, so that appropriate pressure cannot be applied to the joint as in spot welding. A sufficient joint strength could not be obtained.

  In addition, when using a conventional jig that only fixes the entire material, for example, when joining a three-dimensional material such as a vehicle body panel, an appropriate pressure cannot be applied to the material interface. In particular, when the shape accuracy of the material is poor and there is a gap between the materials, there is a problem that the other material cannot be melted by the heat from one material. It has been a conventional problem to be solved.

  The present invention has been made paying attention to the above-described conventional problems, and can be set to a pressure condition suitable for material diffusion at a bonding interface between two different types of materials, and an area within an appropriate condition range. An object of the present invention is to provide a bonding method and a bonding apparatus for different materials, which can be widened and, as a result, can improve the joint strength.

In the bonding method of different materials according to the present invention, when two kinds of materials having different melting points are bonded to each other, a high energy beam is applied to the high melting point material side while applying pressure to at least the bonding portions of the two materials to bring them into close contact with each other. The high-melting-point material is heated to a high temperature in a range where the high-melting-point material is not melted at the joining interface, and only the low-melting-point material is melted and joined by heat conduction from the high-melting-point material. The pressurizing position with respect to the irradiation position is characterized in that the pressure and temperature at the bonding interface are set to be the pressure and temperature at which the low melting point material diffuses without the formation of an intermetallic compound.
A bonding apparatus for different materials according to the present invention is a device for bonding two types of materials having different melting points to each other, condensing a high energy beam and irradiating from the high melting point material side, and this processing A pressurizing unit that applies pressure to the joint portion of the two types of materials and in close contact with each other at the stage of irradiating the high energy beam from the high melting point material side from the head. The pressurizing position is characterized in that the pressure and temperature at the bonding interface are set to a pressure P and a temperature T at which the low melting point material diffuses without generating an intermetallic compound.

According to the present invention, when two types of materials having different melting points are bonded to each other, the bonding interface becomes a pressure condition suitable for the diffusion of the material, and in addition, the area of the appropriate condition range is expanded. The strength per area can be improved, and the joint width can be widened. Therefore, a very excellent effect that the joint strength can be greatly improved is brought about.
In addition, the pressurizing position with respect to the irradiation position of the high energy beam is set so that the pressure and temperature at the bonding interface are the pressure P and temperature T at which the low melting point material diffuses without the generation of the intermetallic compound. As a result, the diffusion is efficiently performed at the pressurization position and the strength per unit area is improved, and the area of the appropriate range of the temperature and the area of the appropriate range of the pressure are both expanded in the diffusion. Since it spreads, joint strength can be improved.

  In the bonding method of different materials according to the present invention, it is possible to employ a configuration in which pressure is applied from the high melting point material side that irradiates at least the high energy beam of the high melting point material and the low melting point material. The joint strength can be improved because it can be joined while pressurizing, and if the high melting point material and the low melting point material are pressurized from both sides, the joining part is pressurized even if the low melting point material is not rigid. Therefore, joint strength can be improved as in the case of pressurization from the high melting point material side.

  Further, in the bonding method of different materials of the present invention, it is possible to adopt a configuration in which at least the rear of the traveling direction of the high energy beam is pressurized, and in this case, the bonding is performed while pressing the position where the material is melted. Therefore, it is possible to increase the joint strength.

  Furthermore, in the bonding method of different materials according to the present invention, the distance between the irradiation position of the high energy beam and the pressing position is set so as to obtain a temperature condition for bonding two different materials with high strength at the pressing position. When this configuration is adopted, diffusion is efficiently performed at the pressurizing position, the strength per unit area is improved, and furthermore, in the diffusion, an area in an appropriate range of temperature and an appropriate pressure The joint area can be improved because the area of the range is expanded and the joining range is expanded.

  Furthermore, in the bonding method of different materials according to the present invention, it is possible to adopt a configuration in which pressure is applied using a roller installed integrally with a processing head for condensing a high energy beam, and processing for condensing a high energy beam. It is possible to employ a configuration in which pressure is applied using a pin installed integrally with the head. In this case, the portion immediately after the high energy beam has passed can be continuously followed by pressure bonding. At this time, it is possible to improve the strength of the joint because it is possible to always weld while holding a part at a certain distance from the irradiation position of the high energy beam. can do.

  On the other hand, in the dissimilar material bonding apparatus according to the present invention, at least the processing head for condensing a high energy beam and irradiating it from the high melting point material side differs from the processing head at the stage of irradiating the high energy beam from the high melting point material side. It can be configured to include a pressurizing unit that applies pressure to the joining portion of two kinds of materials to closely adhere to each other. When two different types of materials are overlapped and joined, In this state, a high energy beam is irradiated toward the high melting point material from the processing head, and heated to a high temperature without melting the high melting point material at the bonding interface. If only the low melting point material is melted and bonded by heat conduction, the bonding interface becomes a pressure condition suitable for the diffusion of the material, and in addition, an appropriate condition is applied. Since the range area is widened, it is possible to improve the strength per unit area, it is possible to widen the bonding width, therefore, it is possible to significantly improve the joint strength.

  Further, in the bonding apparatus for dissimilar materials of the present invention, it is possible to employ a configuration in which a pressurizing means is provided on at least the high melting point material side of the high melting point material and the low melting point material, and pressure is applied from the high melting point material side, In this case, since it is possible to join while pressurizing the melting point, it is possible to improve the joint strength, the pressurizing means is provided on both sides of the high melting point material and the low melting point material, the high melting point material and the low melting point If the material is pressurized from both sides, the joint portion can be pressurized even when the low melting point material is not rigid, so that the joint strength can be improved as in the case of pressing from the high melting point material side.

  Furthermore, in the bonding apparatus for different materials according to the present invention, the pressurizing means may be provided at least rearward in the traveling direction of the high energy beam to pressurize the rearward in the traveling direction of the high energy beam. Since it can join, pressurizing the position where the material is melted, it is possible to increase the joint strength.

  Furthermore, in the bonding apparatus for dissimilar materials according to the present invention, the irradiation position of the high energy beam by the processing head and the pressing position by the pressurizing means so as to obtain a temperature condition for bonding two different kinds of materials with high strength at the pressing position. If this configuration is adopted, diffusion is efficiently performed at the pressurizing position, the strength per unit area is improved, and the temperature is appropriately adjusted in the diffusion. Since both the area of the range and the area of the appropriate range of pressure are expanded and the joining range is expanded, the joint strength can be improved.

  Furthermore, in the bonding apparatus for dissimilar materials of the present invention, a roller installed integrally with a processing head for condensing a high energy beam can be used as a pressing means, and a configuration in which pressure is applied using this roller can be adopted. A pin installed integrally with a processing head for condensing a high energy beam can be used as a pressurizing means, and a configuration in which pressure is applied using this pin can be adopted. In this case, the portion immediately after the high energy beam passes In this case, it is possible to weld while pressing a part that is always a certain distance from the irradiation position of the high energy beam, so that the joint strength can be improved. In addition, it is possible to deal with a three-dimensional workpiece.

  EXAMPLES Hereinafter, although an Example demonstrates this invention still in detail, this invention is not limited to a following example.

[Example 1]
As shown in FIG. 1, the dissimilar material bonding apparatus 1 in this embodiment condenses a high energy beam B and irradiates it from the high melting point material 11 side, and the high energy beam B from the processing head 2. Is provided with a roller (pressurizing means) 3 that applies pressure to the joining portions of two different types of materials 11 and 12 at the stage of irradiating the refractory material 11 toward the high-melting-point material 11. Is attached to the machining head 2 via a guide 4 having a built-in guide, and the pressure applied by the roller 3 is controlled by adjusting the pressure of the air supplied to the air cylinder of the guide 4. .

  In this case, since the roller 3 is integrally provided on the side opposite to the traveling direction of the machining head 2, the roller 3 can be moved following the movement of the high energy beam B, that is, the high energy beam B is always applied. It is possible to move the materials 11 and 12 while pressing them at a rear part that is a certain distance away from the vehicle, and it is possible to follow even when the material is not a two-dimensional shape but a three-dimensional shape such as a car body. . In particular, when the lower material is rigid, for example, as shown in FIG. 2, when the roof 21 is overlapped and joined to the body side outer 22 of the vehicle body, a roller that presses from one side of the material. Or a pin is effective, and it can join only by access from one side.

  In this embodiment, two different types of materials 11 and 12, namely, a steel plate (SPCC) 11 as a high melting point material having a plate thickness t of 1.0 mm and aluminum as a low melting point material having a plate thickness t of 1.0 mm ( A5052) 12 were overlapped with a stacking dimension of 20 mm in width, and were joined using the dissimilar material joining apparatus 1 in the following manner.

  First, pressure is applied to the joint portions of the two materials 11 and 12 by the roller 3 positioned on the opposite side of the processing head 2 from the traveling direction to bring them into close contact with each other.

  Next, the YAG laser B as a high energy beam is applied from the processing head 2 with a laser output of 1.5 kW and a welding speed of 2.5 m / min while pressing the joint portion between the materials 11 and 12 with the roller 3 behind the processing head 2. The center of the overlapping portion was irradiated and heated to a high temperature within a range where the steel plate 11 was not melted at the joining interface, and only the aluminum 12 was melted and joined by heat conduction from the steel plate 11.

  Therefore, when a shear tensile test was performed on the joined portion of the joined steel plate 11 and aluminum 12 in a direction in which a shear force was applied, the strength was about 4000 N (joining width 40 mm), which is a very high value. there were. This is because diffusion was efficiently performed by applying pressure to the melted portion interface.

  FIG. 3 shows the molten state of the material and the interface temperature. When the laser beam B is irradiated, only the aluminum 12 side melts, and the portion where the aluminum 12 is melted immediately after the laser beam B passes is pressed by the roller 3 as described above. As shown in FIG. 5, when no pressure is applied to the bonding interface, the temperature range where favorable diffusion is performed (the portion indicated by hatching) is very narrow, but when pressure is applied, the temperature range where good diffusion is performed widens. . Under the condition above the hatched portion, an intermetallic compound is generated and the bonding strength is lowered. On the other hand, under the condition below the hatched portion, diffusion does not occur and bonding cannot be performed.

  For this reason, it is important to set the pressure point of the roller 3 at a position where the pressure P and the temperature T satisfy the conditions of good diffusion. Although the temperature distribution at the material interface is as shown in FIG. 3, good diffusion is performed by pressurizing the position where the temperature becomes T with the pressure P, and the bonding strength can be increased.

  Further, as shown in FIG. 4, the temperature distribution in the bonding width direction is highest at the center of the beam irradiation position and decreases as the distance from the center increases. When pressure is applied to the bonding interface, the temperature range in which good diffusion is performed is widened, so that even when the pressure is applied in the bonding width direction, the diffusion is performed better than when no pressure is applied. Since the range which becomes large becomes wide, joining width becomes wide and, therefore, joint strength can be improved.

  The optimum pressure point of the roller 3 varies depending on the material and welding conditions, but when the roller 3 needs to be pressed near the beam B, it can be dealt with by devising the cross-sectional shape of the roller 3. . For example, when the position to be pressed is close to the laser beam B and the laser beam B and the roller 3 interfere with each other, as shown in FIG. 6, the roller 33 having a reduced diameter in the width direction central portion 33a. By using this, it is possible to pressurize a position where good diffusion can be performed while avoiding interference between the laser beam B and the roller 33.

[Example 2]
FIG. 7 shows another embodiment of the present invention. As shown in part in FIG. 7, this embodiment differs from the previous embodiment in that the roller 3 is joined to both materials 11 and 12. One of them is arranged on both surfaces of the portion, and both the materials 11 and 12 are sandwiched between these rollers 3 and 3 so as to apply pressure.

  In this case, the upper roller 3 positioned on the laser beam B side is directly attached to the machining head 2 (see FIG. 1), and does not move up and down like the roller 3 of the first embodiment. On the other hand, the lower roller 3 located on the opposite side of the laser beam B is installed with respect to the machining head 2 via a guide 4 (see FIG. 1) in the same manner as the roller 3 of the first embodiment. It is set so that a force in the direction toward the beam B (upward force in the figure) is applied.

  Therefore, in this embodiment, the lower roller 3 is moved so as to be attracted to the upper roller 3, and the joining portion of both materials 11 and 12 is sandwiched between the rollers 3 and 3 and pressed. It is possible to cope with the case where the lower material is not rigid or when the flange is joined.

[Example 3]
FIG. 8 shows still another embodiment of the present invention. As shown in part in FIG. 8, this embodiment is different from the previous embodiment in that the roller 3 is placed before and after the laser beam B. The rollers 3 are arranged one by one, and the rollers 3 are arranged in the vicinity of the back side of the beam irradiation position, and both the materials 11 and 12 are sandwiched between these three rollers 3 in the same manner as in the second embodiment to apply pressure. It is in.

  By arranging the roller 3 in this way, it is possible to suppress a portion closer to the center of the beam irradiation position as compared with the second embodiment, which is suitable when it is necessary to pressurize a position close to the laser beam B. is there.

[Comparative example]
Next, as shown in FIG. 9, a steel plate (SPCC) 11 as a high melting point material having a plate thickness t of 1.0 mm and aluminum (A5052) 12 as a low melting point material having a plate thickness t of 1.0 mm are stacked. The YAG laser beam B was overlapped with a width of 20 mm, and the YAG laser beam B was irradiated to the center of the overlapping portion from the steel plate 11 side at a laser output of 1.5 kW and a processing speed of 2.5 m / min.

  At this time, the welding conditions were set so that the temperature distribution was such that only the aluminum 12 was melted without melting the steel plate 11 side, but the welding condition range in which the material was diffused and could be joined was very narrow.

  Therefore, when a shear tensile test was performed on the bonded portion of the steel plate 11 and the aluminum 12 bonded in this comparative example in a direction in which a shearing force was applied, the strength was about 2000 N (bonding width 40 mm). . That is, compared with Example 1, the strength of the comparative example was very low. This is because no pressure is applied to the interface of the melted portion and diffusion is not performed efficiently. Therefore, by using the joining method and joining apparatus of different materials of Example 1, the joint strength is greatly increased. It was proved that improvement could be realized.

It is side explanatory drawing which shows one Example of the joining apparatus of the dissimilar material of this invention. Example 1 It is joining point explanatory drawing which shows the condition which applied the joining method of the dissimilar material of this invention to the panel joining of the vehicle body. It is a figure explaining the relationship between the molten state of the beam advancing direction of the material joined using this invention, and joining interface temperature. It is a figure explaining the relationship between the molten state of the direction orthogonal to the beam advancing direction of the material joined using this invention, and joining interface temperature. It is a graph which shows the condition range of the pressure and temperature in the joining interface in which favorable spreading | diffusion is performed when it joins using this invention. It is a partial side surface explanatory view showing other examples of a roller of a joining device of different materials of the present invention. (Example 2) It is partial side surface explanatory drawing which shows the other Example of the joining apparatus of the dissimilar material of this invention. (Example 2) FIG. 6 is a partial side view illustrating still another embodiment of the dissimilar material bonding apparatus according to the present invention. (Example 3) It is sectional explanatory drawing which shows the joining method of the conventional different material. (Comparative example)

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Dissimilar material joining apparatus 2 Processing head 3 Roller (pressurizing means)
11 High melting point material 12 Low melting point material B Laser beam (high energy beam)

Claims (10)

When two types of materials having different melting points are overlapped and bonded, a high energy beam is irradiated from the high melting point material side while applying pressure to at least the bonding portions of the two materials to bring them into close contact with each other. In a joining method of dissimilar materials that are heated to a high temperature without melting, and only the low melting point material is melted and joined by heat conduction from the high melting point material,
The pressurizing position with respect to the irradiation position of the high energy beam is set so that the pressure and temperature at the bonding interface are the pressure P and the temperature T at which the low melting point material diffuses without generation of an intermetallic compound . A method for joining different materials.   2. The method for joining different types of materials according to claim 1, wherein pressure is applied from at least one of the high melting point material and the low melting point material which is irradiated with the high energy beam.   3. The method for joining different materials according to claim 1 or 2, wherein at least the rear of the traveling direction of the high energy beam is pressurized.   The method for joining different materials according to any one of claims 1 to 3, wherein pressurization is performed using a roller having a reduced diameter at a central portion in the width direction so as to avoid a laser beam.   The roller is arranged one by one before and after the laser beam, and is arranged in the vicinity of the back side of the beam irradiation position, and both the materials are sandwiched by these rollers to apply pressure. 2. A method for joining different types of materials. In a bonding apparatus of different materials that overlap and bond two kinds of materials having different melting points,
A processing head for condensing a high energy beam and irradiating it from the high melting point material side;
A pressurizing unit that applies pressure to the joint portion of the two types of materials and irradiates the high energy beam from the processing head from the high melting point material side;
The pressure position by the pressurizing means with respect to the irradiation position of the high energy beam is set so that the pressure and temperature at the bonding interface become the pressure P and the temperature T at which the low melting point material diffuses without generation of the intermetallic compound. An apparatus for joining different types of materials, characterized in that it is set.   The apparatus for joining different types of materials according to claim 6, wherein the pressing means is provided on at least the high melting point material side of the two types of materials.   The apparatus for joining different materials according to claim 6 or 7, wherein the pressurizing means is provided at least rearward in the traveling direction of the high energy beam.   The method for joining different materials according to any one of claims 6 to 8, wherein the pressurizing means is a roller having a reduced diameter at a central portion in the width direction so as to avoid a laser beam.   The dissimilar material joining apparatus according to claim 9, wherein one material is disposed before and after the laser beam so as to apply pressure while sandwiching both materials, and a roller is disposed in the vicinity of the back side of the beam irradiation position. .

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