JP4066433B2 - Method and apparatus for joining dissimilar materials by laser irradiation - Google Patents

Description

  The present invention relates to a method and apparatus for joining dissimilar materials by laser welding.

  Recently, demands for higher performance, higher added value and lighter weight have been increasing according to the mechanical performance and usage environment required for many industrial products. Has come to be required at the same time. Therefore, there is an increasing demand for joining different types of materials in welding and joining, which are important assembly production techniques.

  Laser welding is a high-quality, high-precision, low-deformation, high-flexibility, high-speed, and high-productivity joining method that can be robotized, automated, systematized, lined, and labor-saving. is there. Against this background, there is an increasing need for joining dissimilar metal materials by laser welding.

  In fusion welding of dissimilar materials by a combination of greatly different physical properties such as melting point and thermal conductivity or a combination of materials from which an intermetallic compound is generated, it is generally known that joining is very difficult. For example, if an aluminum alloy and a steel-based material are melt-bonded as they are, brittle intermetallic compounds are formed in a wide range, and high temperature cracks are likely to occur, so that sufficient joint strength cannot be obtained. In lap welding, if there is a lot of melting, a large amount of fragile intermetallic compounds are generated and cracks are likely to occur. In addition, since physical properties such as melting point and thermal conductivity are greatly different, when melting and joining as it is, the melting point side and the aluminum alloy side are melted down.

Therefore, when joining different types of materials that generate such intermetallic compounds, a joining method that can suppress the intermetallic compounds while considering various physical property differences is required. The laser welding method makes it relatively easy to suppress the formation of intermetallic compounds by controlling the melting of joints of dissimilar materials, taking advantage of the high directivity of the high energy density beam heat source and the short heating / cooling rate. When joining dissimilar materials using lasers, as in normal welding, if the dissimilar material joints are melted together and mixed together, a wide solid-liquid coexistence region and a composition region where intermetallic compounds are generated are formed over a wide area. , Hot cracking will occur. Further, when the intermetallic compound layer is thick, the bonding strength is extremely reduced. For this reason, it is important to melt one material and suppress melting of the other, or to melt the two metals thinly and minimize the generation of intermetallic compounds generated at the bonding interface. It is. Recently, various studies have been made on the joining of steel materials and aluminum alloys, copper, titanium, etc. using high-performance YAG lasers or CO ₂ lasers, but aluminum alloys and copper alloys have high laser reflectivity. There is a disadvantage that laser irradiation heat input is not fully utilized.

Various studies have been made on bonding methods other than lasers. For example, in rolling joining, preheating of the joining material is necessary. When the preheating temperature is low, it is necessary to increase the rolling reduction, and surface cracks are likely to occur. Also, it is very important to clean the joint surface. For example, in the case of having a strong oxide film on the surface, such as aluminum, mechanical pretreatment or flux application is required. Moreover, when flux is applied, there is a drawback that the flux must be removed as a post treatment.
JP-A-6-218533 Japanese Patent No. 3535152 Japanese Patent No. 3692135

  This patent publication describes a technique for irradiating a gap between two metal plates to be joined with an excimer laser, removing oxides on the surface of the metal plates, and activating them for pressure welding.

  The present invention has been made in view of the above circumstances, and the purpose of the present invention is to fully utilize laser irradiation heat input when bonding dissimilar materials to cover greatly different physical property differences such as melting point and thermal conductivity. However, the production of intermetallic compounds is minimized, there is no need for preheating, excessive pretreatment and posttreatment, and a dissimilar material capable of obtaining a joint having high shear strength and peel strength. It is to provide a bonding method and apparatus.

  Therefore, in the present invention, a laser pressure welding method combining a laser and a roller is proposed as one of the different metal bonding methods, and it was developed for the purpose of establishing a high-speed and stable bonding method in various combinations of different metals.

  In the present invention, the effect of both fusion welding and pressure welding can be obtained by the combination of the laser and the roller, and the temperature of the bonding interface can be controlled by freely irradiating the laser beam with a scanner or the like. In addition, after bonding different types of metal plates and irradiating and scanning the laser beam to the mating surface, it is bonded by pressing with a roller, so that bonding on the surface is possible, and even for metals with high laser reflectivity, Since heat loss can be reduced, the formation of fragile intermetallic compounds can be minimized while covering large physical property differences.

According to the first method of joining different types of joining materials by laser irradiation of the present invention, two plate-like materials of different materials are combined, a laser beam is irradiated in the vicinity of the joint, and two pairs of rollers are opposed to each other. This is a method for producing a different type of bonding material obtained by pressurizing and bonding in the direction in which the plate-shaped material contacts. The laser beam is irradiated at the joint, and the laser beam is irradiated at a position shifted from the joint toward one of the plate-like materials, and the irradiated plate-like material is biased until the melting temperature of the plate-like material is reached. The heating step and the irradiation surface of one plate-like material biased by laser irradiation are combined with the other plate-like material, and the joint peeling measured in advance in the direction in which the two plate-like materials come into contact with the roller Applying a pressurizing force which is a contact pressure for shifting from a base material fracture of a different type of joining material to a base material fracture .

  Furthermore, the second method for bonding different types of bonding materials by laser irradiation according to the present invention is characterized in that, in the partial heating step, a laser beam is irradiated in parallel to the joint of the plate-like material.

  Furthermore, the third method for bonding different types of bonding materials by laser irradiation of the present invention is characterized in that, in the step of partial heating, the laser beam is irradiated while being inclined with respect to the joint of the plate-like material.

  Furthermore, in the fourth method of joining different types of joining materials by laser irradiation according to the present invention, in the step of partial heating, the two plate-like materials constituting the seam are alternately irradiated with a laser beam, and either one of the plates It is characterized in that the irradiation time to the shaped material is increased.

  Further, according to the fifth method of joining different kinds of joining materials by laser irradiation of the present invention, the central axes of the pair of rollers are moved in parallel to the joint of the plate-like material, and the joint is moved to any one of the plate-like materials. The laser beam is irradiated to the shifted position to perform partial heating.

  Furthermore, the sixth method for bonding different types of bonding materials by laser irradiation is characterized in that the seam is shielded by an inert gas or vacuum.

According to the seventh apparatus for joining different types of joining materials by laser irradiation, two plate-like materials of different materials are combined, a laser beam is irradiated in the vicinity of the joint, and two plates are formed by a pair of opposing rollers. This is an apparatus for producing a different type of bonding material formed by pressurizing and bonding in the direction in which the material contacts. The laser beam is irradiated at the joint, and the laser beam is irradiated at a position shifted from the joint toward one of the plate-like materials, and the irradiated plate-like material is biased until the melting temperature of the plate-like material is reached. A heating unit that heats, and a joint that is measured in advance in the direction in which the two plate-shaped materials come into contact with each other by combining the irradiation surface of one plate-shaped material that is biased by laser irradiation and the other plate-shaped material. It has a pressurizing unit that applies a pressing force that is a contact pressure that shifts from peeling to a base material fracture of a dissimilar bonding material, and a control unit that controls the pressing force to apply this pressing force. To do.

  Furthermore, in the eighth apparatus for joining different types of joining materials by laser irradiation, in the heating unit, the irradiation direction of the laser beam is moved in parallel to the joint, and shifted from the joint to one of the plate-like materials. The plate-shaped material is heated unevenly by irradiating the position with a laser beam.

  Furthermore, the ninth apparatus for joining different types of joining materials by laser irradiation in the heating unit is a position in which the irradiation direction of the laser beam is inclined with respect to the joint in the heating unit and shifted from the joint to one of the plate-like materials. The plate-shaped material is heated unevenly by irradiating with a laser beam.

  Furthermore, in the tenth laser irradiation joining apparatus of different types of bonding material according to the present invention, in the heating unit, the irradiation direction of the laser beam is moved zigzag with respect to the joint, and the irradiation time of any one of the plate-like materials from the joint is as follows. It is characterized by unevenly heating the plate-like material by irradiating so as to increase.

  Furthermore, the eleventh laser irradiation joining apparatus of different types of the present invention is such that in the heating unit, the center axis of the pair of rollers is moved in parallel to the joint, so that any one of the plate-like materials from the joint. The plate material is heated unevenly by irradiating a position shifted to the side with a laser beam.

  Furthermore, the twelfth laser irradiation apparatus for bonding different types of materials according to the present invention is characterized by having a shield unit that shields the seam with an inert gas or vacuum.

The present invention has the following effects.
According to the first aspect of the present invention, the different types of materials can be joined by irradiating a laser beam onto the mating surfaces of the different types of materials, heating them unevenly, and then applying a pressure higher than the contact pressure by a roller. Can be joined in a combination of materials. The heat input loss can be reduced by irradiating the mating surfaces of different materials with laser. Furthermore, composition control is facilitated by irradiating a laser to one of the dissimilar bonding materials and biasing heating, and bonding is possible even in a combination in which physical property differences such as thermal conductivity and melting point are greatly different. In particular, in the combination of dissimilar metals that generate intermetallic compounds, it is possible to minimize the generation of intermetallic compounds for the above reasons together with the rapid heating and cooling effect of the laser, and excellent mechanical strength characteristics. Different types of bonding materials can be manufactured. In particular, by applying a pressure higher than the adhesion pressure, it is possible to manufacture a dissimilar bonding material that can be bonded to a dissimilar material that has conventionally been difficult to bond and has sufficient mechanical strength characteristics.

  The apparatus for joining dissimilar materials by laser irradiation according to claim 7 of the present invention irradiates the mating surface of dissimilar materials with laser, performs partial heating by the heating unit, checks the degree of heating by the detection unit, and by the pressure control unit, By applying a pressing force equal to or higher than the contact pressure, it is possible to join in a combination of various different materials.

  Embodiments of the present invention will be described below with reference to the drawings. However, the example shown below illustrates the method for embodying the technical idea of the present invention, and the method of the present invention is not specified to the following.

  The best mode for carrying out the present invention will be described below with reference to the drawings.

  1 to 5, the dissimilar materials are joined by the laser irradiation by combining the first plate material 3 and the second plate material 4 of different materials, irradiating the laser 1 near the joint, and by the roller 2. Press to join. In this method, the laser 1 is irradiated to either the position 5 shifted from the mating surface to the first plate material 3 or the position 6 shifted to the second plate material 4, and the first plate material 3 or The step of partial heating until the temperature reaches a temperature around the melting temperature of the second plate-shaped material 4, the irradiation surface of one plate-shaped material heated by the laser 1 together with the other plate-shaped material, and the combined surface; The dissimilar bonding material is manufactured by applying a pressure higher than the contact pressure by the roller 2 to the surface.

  The shield unit 7 shields the mating surfaces with an inert gas or vacuum to prevent oxidation of the bonding side surface.

  The detection unit 8 is a temperature sensor, for example, and detects the heating state of the laser irradiation unit or one of the plate-like materials. The detection unit 8 is connected to the control unit 9, and the control unit 9 is connected to the pressure unit 10. The heating condition is detected by the detection unit 8, and the detected data is sent to the control unit 9, and the pressurizing unit 10 is controlled in order to apply a pressure higher than the contact pressure by the heating condition. By detecting the heating condition and controlling the applied pressure, it can be applied to various different materials, and a constant pressure can be always applied.

The laser 1 is a YAG laser, a CO ₂ laser, a semiconductor laser, a fiber laser, or the like.

  The laser 1 heats the first plate material 3 or the second plate material 4 in an uneven manner. The method of partial heating will be described in detail below.

  A method of partial heating will be described with reference to FIGS.

  In FIG. 1, a laser beam 1 is used to irradiate a laser 1 with a free trajectory, and irradiate positions 5 and 6 shifted to either the first plate-like material 3 or the second plate-like material 4 side. It is possible to heat unevenly. The laser 1 can be guided to the beam scanner 11 by a mirror or an optical fiber.

  As shown in FIG. 2, the laser 1 is moved in parallel to the first plate-like material 3 or the second plate-like material 4 side, and irradiated to the positions 5 and 6 shifted to either one.

  In FIG. 3, the laser 1 is irradiated while being inclined with respect to the mating surface, and is irradiated by irradiating the positions 5 and 6 shifted to either the first plate material 3 or the second plate material 4 side. Can be heated.

  In FIG. 4, the laser 1 is irradiated to the mating surface while being moved in a zigzag 12 so that the irradiation time of either the first plate material 3 or the second plate material 4 is increased. Can be heated unevenly.

  As shown in FIG. 5, the center axis of the roller holder 13 is moved in parallel with the mating surface, and is shifted to positions 5 and 6 shifted to either the first plate material 3 or the second plate material 4 side. Uneven heating can be performed by irradiating the laser 1.

  The contact pressure will be described with reference to FIG. FIG. 6 shows the relationship between the pressure applied to the roller 2 and the peel strength of the manufactured different bonding material in the method for bonding different materials by laser irradiation. The first plate material 3 at this time is an A6061 aluminum alloy, and the second plate material 4 is a cold rolled steel plate (SPCC steel). The bonding material is a band material having a thickness of 1 mm, a width of 12 mm, and a length of 300 mm. For joining, these two sheets are combined, and the joint is irradiated by laser irradiation. The experimental conditions are as follows: laser output is 1800 W, laser scan speed is 70 Hz, laser defocus distance is +7 mm, laser irradiation position is 1.0 mm toward the SPCC side, roller 2 pressure 163 to 245 MPa, and belt feed rate is 0.5 m. / Min. As a result of the peeling test, when the roller 2 pressure was 163 MPa or less, peeling occurred from the joint. A high joint strength that breaks from the base material of the A6061 aluminum alloy at 245 MPa or more could be obtained. In this case, the contact pressure refers to 245 MPa or more.

  This region that shifts from the joint peeling to the base material breakage is referred to as a contact pressure region 14. The contact pressure region varies depending on the material to be joined.

1 is a conceptual diagram of an apparatus according to an embodiment of the present invention. Schematic diagram in which the laser beam of the present invention is moved in parallel with the mating surface and irradiated to a position shifted to either one of the plate-shaped materials for uneven heating Schematic of irradiation by tilting the laser beam of the present invention with tilting with respect to the mating surface Schematic of uneven heating by irradiating the laser of the present invention to the mating surface in a zigzag manner Schematic of uneven heating by moving the roller holder of the present invention Contact pressure range

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Laser 2 ... Roller 3 ... 1st plate-shaped material 4 ... 2nd plate-shaped material 5 ... The position shifted from the joint to the 1st plate-shaped material side 6 ... The 2nd plate-shaped material side from the joint 7: Shield unit 8 ... Detection unit 9 ... Control unit 10 ... Pressure unit 11 ... Beam scanner 12 ... Laser zigzag irradiation locus 13 ... Roller holder 14 ... Contact pressure area 15 ... Laser oscillator

Claims (12)

Two kinds of plate-like materials of different materials are combined, a laser beam is irradiated in the vicinity of the joint, and the pair of rollers facing each other is pressed and joined in a direction in which the two plate-like materials come into contact with each other. A method of manufacturing a bonding material,
Irradiating a laser beam at the joint to the two plate-like materials, and irradiating the laser beam to a position shifted from the joint to either one of the plate-like materials, Uneven heating the material until it reaches the melting temperature of the plate-like material;
Combining the laser beam irradiation surface of the one plate-like material that has been polarized heated by irradiation with the other plate-like material, wherein the roller in the direction of contact the two plate-like material by a heterologous junction peel measured in advance A step of applying a pressing force that is a contact pressure for shifting to a base material fracture of the bonding material ;
A method for producing a heterogeneous bonding material characterized by comprising:   2. The method for producing a heterogeneous bonding material according to claim 1, wherein in the partial heating step, a laser beam is irradiated in parallel to the joint of the plate-like material.   2. The method of manufacturing a heterogeneous bonding material according to claim 1, wherein in the step of biasing heating, the laser beam is irradiated while being inclined with respect to the joint of the plate-like material.   The laser beam is alternately irradiated to the two plate-like materials constituting the joint in the partial heating step, and the irradiation time to one of the plate-like materials is increased. A method for producing the dissimilar bonding material according to 1.   The center axis of the pair of rollers is moved in parallel to the joint of the plate-like material, and the laser beam is irradiated to a position shifted from the joint to either one of the plate-like materials to perform partial heating. The method for producing a dissimilar bonding material according to claim 1.   6. The method for producing a dissimilar bonding material according to claim 1, further comprising a step of shielding the seam with an inert gas or a vacuum. Two kinds of plate-like materials of different materials are combined, a laser beam is irradiated in the vicinity of the joint, and the pair of rollers facing each other is pressed and joined in a direction in which the two plate-like materials come into contact with each other. An apparatus for producing a bonding material,
Irradiating a laser beam at the joint to the two plate-like materials, and irradiating the laser beam to a position shifted from the joint to either one of the plate-like materials, A heating unit for unevenly heating the material until it reaches the melting temperature of the plate-like material,
Dissimilar bonding material from the joint peeling measured in advance in the direction in which the two plate-shaped materials are brought into contact with each other by the roller by combining the irradiation surface of one plate-shaped material that is biased by laser irradiation and the other plate-shaped material A pressurizing unit for applying a pressurizing force that is a contact pressure for shifting to a base material breakage of
The control unit for controlling the pressure to apply the pressure,
An apparatus for producing a different kind of bonding material characterized by comprising:   In the heating unit, the irradiation direction of the laser beam is moved in parallel to the joint, and the laser beam is irradiated to a position shifted from the joint to one of the plate-like materials, thereby deflecting the plate-like material. The apparatus for producing a different type of bonding material according to claim 7, wherein heating is performed.   In the heating unit, the irradiation direction of the laser beam is inclined with respect to the seam, and the laser beam is irradiated to a position shifted from the seam to any one of the plate-like materials, thereby unevenly heating the plate-like material. An apparatus for producing a heterogeneous bonding material according to claim 7.   In the heating unit, the irradiation direction of the laser beam is moved in a zigzag manner with respect to the joint, and irradiation is performed from the joint so as to increase the irradiation time of one of the plate-like materials, so that the plate-like material is biased. The apparatus for producing a different type of bonding material according to claim 7, wherein heating is performed.   In the pressure unit, the center axis of a pair of rollers is moved in parallel to the joint, thereby irradiating a laser beam at a position shifted from the joint to any one of the plate-like materials, The apparatus for producing a heterogeneous bonding material according to claim 7, wherein the plate-like material is heated unevenly.   The apparatus for producing a heterogeneous bonding material according to any one of claims 7 to 11, further comprising a shield unit that shields the seam with an inert gas or a vacuum.

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