Method for manufacturing joined body

Abstract

To provide a method for manufacturing a joined body in which a decrease in joint strength at the outermost peripheral part of a range to be joined of a metal member to which a joint member is joined is suppressed.SOLUTION: A method for manufacturing a joined body includes: a laser irradiation step of irradiating a laser irradiation range set on a surface of a metal member with a laser beam of pulse oscillation to form a concave-convex part having a concave-convex shape on the surface of the metal member, and depositing metal particles generated due to the metal member melted by the laser beam in each of a region adjacent to a scanning line irradiated with the laser beam and a region of the scanning line; and a joining step of joining a joint member to a range to be joined which is at least a part of the laser irradiation range. In the laser irradiation step, a scanning path of the laser beam is set such that a scanning line which becomes the lowermost stream of a scanning direction of the laser beam does not become a scanning line of the outermost peripheral part of the range to be joined.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present disclosure relates to a method for manufacturing a joined body, and more particularly to a method for manufacturing a joined body in which a joining member is joined to a metal member. [Background technology]

[0002] When manufacturing a joined body in which a joining member such as a resin member is joined to a metal member, it has been considered to roughen the surface of the metal member by providing fine irregularities on the surface in order to improve adhesion between the metal member and the joining member.

[0003] Patent Document 1 discloses a resin molded body in which a metal member is covered with a resin member made of a resin material in a state in which a part of the metal member is exposed, and a joint made of irregularities is formed in the part of the metal member covered with the resin member, the joint being made of irregularities having a first irregularity and a second irregularity formed at a position including the surface of the first irregularity and having a smaller height difference than the first irregularity, and the resin member is joined to the joint by filling the resin material into the irregularities, and a method for manufacturing the resin molded body. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2019-119093 A Summary of the Invention [Problem to be solved by the invention]

[0005] In such a joined body such as a resin molded body, the metal member to which the joining member is joined in the joined area on the surface of the metal member has a joining portion where the metal member is joined to the resin member and an unjoined portion where the metal member is not joined to the resin member. The boundary between the joining portion and the unjoined portion is prone to cracking because stress caused by the action of external forces and temperature changes is concentrated. Therefore, the outermost periphery of the joined area that contacts the boundary is required to have a joining strength that does not easily crack the boundary. When forming an uneven portion having an uneven shape on the surface of the metal member by irradiating it with a laser beam before joining it with the joining member, the technology described in Patent Document 1 has a problem that the joining strength at the outermost periphery of the joined area of ​​the metal member to which the joining member is joined may decrease because the scanning path of the laser beam is not appropriately set.

[0006] The present disclosure has been made to solve such problems, and aims to provide a method for manufacturing a joined body that suppresses a decrease in joining strength at the outermost periphery of the joining area of ​​the metal members to which the joining member is joined. [Means for solving the problem]

[0007] A method for manufacturing a joined body in one embodiment includes a laser irradiation step of irradiating a pulsed laser beam onto a laser irradiation range set on the surface of a metal member to form an uneven portion having an uneven shape on the surface of the metal member, and depositing metal particles generated due to the metal member melted by the laser beam in an area adjacent to the scan line irradiated by the laser beam and in an area of ​​the scan line, and a joining step of joining a joining member to a joining area which is at least a part of the laser irradiation range, wherein in the laser irradiation step, the scanning path of the laser beam is set so that the scan line furthest downstream in the scanning direction of the laser beam is not a scan line on the outermost periphery of the joining area. Effect of the Invention

[0008] The present disclosure makes it possible to provide a method for manufacturing a joined body that suppresses a decrease in the joining strength at the outermost periphery of the joined area of ​​the metal members joined with a joining member. [Brief description of the drawings]

[0009] [Figure 1] 4 is a flowchart showing a method for manufacturing a bonded body according to the first embodiment. [Diagram 2] 10A to 10C are cross-sectional views illustrating a laser irradiation step. [Diagram 3] 1A is a plan view of a metal member and a side view of a joined body, showing a first example of a scanning path of a laser beam. [Figure 4] 13A is a plan view of a metal member and a side view of a joined body, showing a second example of a scanning path of a laser beam. FIG. [Diagram 5] 13A and 13B are a plan view of metal members and a side view of a joined body, showing a third example of a scanning path of a laser beam. [Figure 6] 11A and 11B are a plan view of a metal member and a side view of a joined body, illustrating a comparative example of a scanning path of a laser beam. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] First embodiment Hereinafter, an embodiment of the present disclosure will be described with reference to the drawings. However, the present disclosure is not limited to the following embodiment. In addition, in order to clarify the description, the following description and drawings are appropriately simplified. What is shown in the drawings is only a part of the whole, and in reality, many other configurations that are not shown are included. In the following description, the same or equivalent elements are given the same reference numerals, and duplicated descriptions are omitted.

[0011] Fig. 1 is a flowchart showing a method for manufacturing a bonded body according to the first embodiment. As shown in Fig. 1, the method for manufacturing a bonded body according to the present embodiment includes a laser irradiation step (step S10) and a bonding step (step S20). First, the laser irradiation step of step S10 will be described with reference to Fig. 2. Fig. 2 is a cross-sectional view for explaining the laser irradiation step.

[0012] As shown in Fig. 2, the laser irradiation step is a step of irradiating a pulsed laser beam onto a laser irradiation range R1 set on the surface 1a of the metal member 1 to form an uneven portion 1b having an uneven shape on the surface 1a of the metal member 1, and depositing metal particles 1p generated due to the metal member 1 melted by the laser beam in an area A2 adjacent to the scanning line L1 irradiated with the laser beam and an area A1 of the scanning line L1. Note that the upper side of Fig. 2 shows a partial cross-sectional view of the metal member 1 during irradiation with the laser beam, and the lower side of Fig. 2 shows a cross-sectional view of the metal member 1 after irradiation with the laser beam.

[0013] The metal member 1 is a metal plate made of a metal material containing at least one of Cu, Al, Ti, and Fe as a main component. The entire metal member 1 or at least its surface 1a may be made of the above-mentioned metal material. The metal member 1 before the uneven portion 1b is formed has a flat plate shape. In this embodiment, the metal member 1 has a substantially rectangular (square or oblong) planar shape, but the planar shape of the metal member 1 is not limited to a substantially rectangular shape and may be another shape such as a substantially polygonal shape or a substantially circular shape.

[0014] In the laser irradiation process, a laser beam is irradiated to a laser irradiation area R1 according to a predetermined scanning path under predetermined irradiation conditions. Since the laser beam is a pulsed oscillation, it is irradiated for each irradiation spot having a predetermined laser spot diameter. By irradiating the laser irradiation area R1 with the laser beam according to a predetermined scanning path, scanning lines (scanning lines L1 and L2 in FIG. 2) that are laser irradiation marks are formed in each of the adjacent areas (areas A1 and A2 in FIG. 2) of the laser irradiation area R1.

[0015] In this embodiment, the metal member 1 is made of a metal material mainly composed of Cu. When the metal member 1 is made of a metal material mainly composed of Cu, the laser beam irradiation conditions are preferably a laser wavelength of 1060 to 1070 nm, a pulse energy of 0.5 to 2.0 mJ, a pulse width of 1 to 300 ns, a laser spot diameter (diameter of each region) of 50 to 90 μm, and a spot interval (interval between adjacent regions) equal to or less than the laser spot diameter. The laser beam irradiation conditions can be appropriately determined depending on the metal member 1 used.

[0016] In order to form the uneven portion 1b on the surface 1a, first, a laser beam is irradiated onto an area A2 of the surface 1a, thereby forming a scanning line A2 in the area A2, and the metal in the area A2 where the scanning line A2 is formed is melted. In this embodiment, the metal melted from the metal member 1 is referred to as molten metal. The molten metal then evaporates and is released into the gas atmosphere. In this embodiment, the metal evaporated from the molten metal is referred to as metal vapor. The metal vapor remains in the gas atmosphere, and over time, it condenses and becomes particles as it is, or reacts with the gas and becomes particles. In this embodiment, the metal that has become particles from the metal vapor is referred to as metal particles 1p. The metal particles 1p are then deposited in the area A2 of the scanning line L2 irradiated with the laser beam.

[0017] When the metal particles 1p deposited in the region A2 are solidified, the region A1 adjacent to the scanning line L2 of the surface 1a is also irradiated with the laser beam, so that the scanning line L1 is formed in the region A1. As a result, the metal particles 1p generated from the metal in the region A1 are deposited in each of the region A1 of the scanning line L1 irradiated with the laser beam and the region A2 where the scanning line L2 is formed (more specifically, the deposit in the region A2). That is, after the scanning line L2 is formed in the region A2, when the adjacent region A1 is irradiated with the laser beam, the metal particles 1p generated from the metal in the region A1 are deposited in each of the regions A1 and A2. At this time, the deposit in the region A2 where the scanning line L2 has already been formed grows due to the deposition of the metal particles 1p flying from the region A1 of the scanning line L1 irradiated with the laser beam. Such irradiation of the laser beam is repeated in the laser irradiation range R1 of the whole or part of the surface 1a.

[0018] In addition, among the deposits in region A2 where the scanning line L2 has already been formed, the metal particles 1p are not deposited in the parts that are shaded with respect to the scattering direction of the metal particles 1p flying from the adjacent region A1 (projection effect). Therefore, the deposits in region A2 after the metal particles 1p fly in from the adjacent region A1 do not become too fine, but grow to have an uneven shape of, for example, nm order.

[0019] Through the above-mentioned laser irradiation process, as shown in the lower part of FIG. 2, a metal member 1 is obtained in which an uneven portion 1b is formed in a laser irradiation range R1 set on the surface 1a. In this laser irradiation process, metal particles 1p scattered from a region A1 of the scanning line L1 irradiated with the laser beam are deposited in a region A2 adjacent to the scanning line L1. Therefore, when comparing a region (e.g., region A1) in which a scanning line (e.g., scanning line L1) located at the most downstream in the scanning direction is formed with a region (e.g., scanning line L2) located upstream in the scanning direction from the scanning line (e.g., region A2), the amount of metal particles 1p deposited in the former region is smaller than that in the latter region. In other words, the height difference of the uneven portion 1b in the thickness direction of the metal member 1 perpendicular to the surface 1a is smaller in the region in which a scanning line located at the most downstream in the scanning direction is formed than in the region in which a scanning line located upstream in the scanning direction from the scanning line is formed. Therefore, there is a risk that the bonding strength between the bonding member 2 and the region where the scanning line is formed, which is the most downstream in the scanning direction, will be reduced compared to other regions in the laser irradiation range R1.

[0020] Therefore, in the laser irradiation process, the scanning path of the laser beam is set so that the scanning line at the most downstream of the scanning direction of the laser beam does not become the scanning line of the outermost periphery of the joining area R2, which is at least a part of the laser irradiation area R1. As a result, the metal particles 1p are deposited in a sufficient amount in the outermost periphery area where the scanning line is formed, so that the height difference of the unevenness 1b in this area can be suppressed from becoming smaller than that in other areas. As a result, it is possible to suppress a decrease in the joining strength in the outermost periphery of the joining area R2 of the metal member 1 to which the joining member 2 is joined. An example of such a scanning path of the laser beam will be described with reference to FIGS. 3 to 5. The arrows shown in the plan views of FIGS. 3 to 5 indicate the scanning direction of the laser beam.

[0021] FIG. 3 is a plan view of a metal member and a side view of a joined body showing a first example of a scanning path of a laser beam. As shown in the plan view of FIG. 3, in the first example, when the scanning direction is the circumferential direction of the metal member 1, the scanning path is set for the joining area R2, which is the laser irradiation area R1, so as to move from the outer periphery side to the inner periphery side of the metal member 1. In the case of the scanning path shown in FIG. 3, the laser beam can be scanned so as to rotate along the circumferential direction from the scanning start position S1 to the scanning end position G1. Here, the scanning start position S1, which is the first irradiation position of the laser beam, is set to the outermost periphery of the joining area R2 (laser irradiation area R1) where the outermost periphery scanning line L8 is formed, and the scanning end position G1, which is the last irradiation position of the laser beam, is set to the center of the joining area R2 (laser irradiation area R1) where the innermost periphery scanning line L1 is formed. That is, the scanning start position S1 and the scanning end position G1 are set inside the joining area R2.

[0022] For example, the laser beam is first scanned in one direction along the circumferential direction from the scanning start position S1 to form a scanning line L8 in the welding area R2, and then shifted to the inside of the scanning line L8 so as to approach the center of the welding area R2, and scanned in one direction along the circumferential direction again to form a scanning line L7 in the welding area R2. In this way, by irradiating the laser beam from the scanning start position S1 to the scanning end position G1 according to the scanning path shown in FIG. 3, the scanning lines L8, L7, L6, L5, L4, L3, L2, and L1 that go around in the circumferential direction are sequentially formed in the welding area R2. Then, after forming the scanning line L1 that is the most downstream in the scanning direction, the scanning of the laser beam is stopped at the scanning end position G1. By irradiating the welding area R2 with the laser beam according to the scanning path shown in FIG. 3, the scanning lines L1 to L8 are formed in the areas A1 to A8 that are adjacent to each other in the welding area R2.

[0023] Referring to a scanning electron microscope (SEM) image of a portion of region A8 of an actually manufactured metal member 1 enlarged, it can be seen that an uneven portion 1b having a suitable uneven shape on the order of nm is formed in region A8. On the other hand, referring to a SEM image of a portion of region A1 of an actually manufactured metal member 1 enlarged, it can be seen that a suitable uneven shape is not formed in region A1.

[0024] Next, FIG. 4 is a plan view of a metal member and a side view of a joined body showing a second example of the scanning path of the laser beam. As shown in the plan view of FIG. 4, in the second example, when the scanning direction is the circumferential direction of the metal member 1, the scanning path is set in the laser irradiation range R1 including the welding range R2 so as to go from the inner periphery side to the outer periphery side of the metal member 1. In the case of the scanning path shown in FIG. 4, the laser beam can be scanned so as to rotate along the circumferential direction from the scanning start position S2 to the scanning end position G2. Here, the scanning start position S2, which is the first irradiation position of the laser beam, is set to the center of the laser irradiation range R1 where the innermost scanning line L8 is formed and the center of the welding range R2, and the scanning end position G2, which is the last irradiation position of the laser beam, is set to the outer periphery protruding from the welding range R2 of the laser irradiation range R1 where the outermost scanning line L1 is formed. That is, the scanning start position S2 is set inside the welding range R2, and the scanning end position G2 is set outside the welding range R2 and inside the laser irradiation range R1. The outer periphery of the laser irradiation range R1 becomes an unjoined portion of the metal member 1.

[0025] For example, the laser beam is first scanned in one direction along the circumferential direction from the scanning start position S2 to form a scanning line L8 in the laser irradiation range R1, and then shifted to the outside of the scanning line L8 so as to move away from the center of the laser irradiation range R1, and scanned again in one direction along the circumferential direction to form a scanning line L7 in the laser irradiation range R1. In this way, by irradiating the laser beam from the scanning start position S2 to the scanning end position G2 according to the scanning path shown in FIG. 4, the scanning lines L8, L7, L6, L5, L4, L3, L2, and L1 that each go around in the circumferential direction are sequentially formed in the laser irradiation range R1. Then, after forming the scanning line L1 that is the most downstream in the scanning direction, the scanning of the laser beam is stopped at the scanning end position G2. By irradiating the laser beam to the laser irradiation range R1 according to the scanning path shown in FIG. 4, the scanning lines L1 to L8 are formed in the areas A1 to A8 that are adjacent to each other in the laser irradiation range R1.

[0026] Referring to an enlarged SEM image of a portion of region A4 of an actually manufactured metal member 1, it can be seen that an uneven portion 1b having a suitable uneven shape on the order of nm is formed in region A8. On the other hand, referring to an enlarged SEM image of a portion of region A1 of an actually manufactured metal member 1, it can be seen that a suitable uneven shape is not formed in region A1.

[0027] Next, FIG. 5 is a plan view of a metal member and a side view of a bonded body showing a third example of a scanning path of a laser beam. As shown in the plan view of FIG. 5, in the third example, when the scanning direction is a first direction along the surface 1a of the metal member 1, the scanning path is set to a laser irradiation range R1 including a bonding range R2 so as to go from one side to the other side of a second direction perpendicular to the first direction. In the case of the scanning path shown in FIG. 5, the laser beam is alternately scanned from the scanning start position S3 to the scanning end position G3 in a right direction from the left side, which is one side of the first direction, to the right side, which is the other side, and in a left direction from the right side to the left side of the first direction, so as to go from the upper side, which is one side of the second direction, to the lower side, which is the other side. Here, the scanning start position S3, which is the first irradiation position of the laser beam, is set to the outer periphery of the laser irradiation range R1 where the uppermost scanning line L9 is formed, which is outside the welding range R2, and the scanning end position G3, which is the last irradiation position of the laser beam, is set to the outer periphery of the laser irradiation range R1 where the lowermost scanning line L1 is formed, which is outside the welding range R2. That is, the scanning start position S3 and the scanning end position G3 are set outside the welding range R2 and inside the laser irradiation range R1. Note that the outer periphery of the laser irradiation range R1 becomes an unwelded portion of the metal member 1.

[0028] For example, the laser beam is first scanned rightward along the left-right direction from the scanning start position S3 to form a scanning line L9 in the laser irradiation range R1, and then shifted downward to the scanning line L9 so as to approach the lower end of the laser irradiation range R1, and scanned leftward again along the left-right direction to form a scanning line L8 in the laser irradiation range R1. In this way, by irradiating the laser beam from the scanning start position S3 to the scanning end position G3 according to the scanning path shown in FIG. 5, the scanning lines L9, L8, L7, L6, L5, L4, L3, L2, and L1 each extending along the left-right direction are sequentially formed in the laser irradiation range R1. Then, after the laser beam forms the scanning line L1 which is the most downstream in the scanning direction, the scanning is stopped at the scanning end position G3. By irradiating the laser beam to the laser irradiation range R1 according to the scanning path shown in FIG. 5, the scanning lines L1 to L9 are formed in the areas A1 to A9 adjacent to each other in the laser irradiation range R1.

[0029] Referring to an enlarged SEM image of a portion of region A2 of an actually manufactured metal member 1, it can be seen that an uneven portion 1b having a suitable uneven shape on the order of nm is formed in region A2. On the other hand, referring to an enlarged SEM image of a portion of region A1 of an actually manufactured metal member 1, it can be seen that a suitable uneven shape is not formed in region A1.

[0030] Next, the joining process of step S20 is a joining process in which the joining member 2 is joined to the joining area R2, which is at least a part of the laser irradiation area R1. The joining member 2 is made of a resin material including a thermoplastic resin such as polyphenylene sulfide (PPS) resin or polypropylene (PP) resin, or a thermosetting resin such as an epoxy resin. The types of the thermoplastic resin and the thermosetting resin are not limited to these, and can be appropriately selected depending on the application. For example, an adhesive can be used as the joining member 2. As the adhesive, a compound that includes the above-mentioned thermoplastic resin or thermosetting resin and exhibits adhesiveness can be used. The type of the adhesive is not limited to these, and can be appropriately selected depending on the application. In the joining process, a molten resin material is poured into the concaves of the uneven shape of the joining area R2 and solidified to form a joined body 10 (10a, 10b, or 10c).

[0031] As a method of joining the joining member 2 to the joining area R2 of the metal member 1, an appropriate method can be adopted depending on the resin used. When a thermoplastic resin is used, the metal member 1 having the uneven portion 1b formed on the surface 1a is inserted into an injection molding die, and the joining member 2 may be joined to the joining area R2 of the metal member 1 by insert molding in which a molten resin material is injected toward the joining area R2 of the inserted metal member 1. Alternatively, for example, the joining member 2 may be joined to the joining area R2 of the metal member 1 by thermocompression bonding using a means such as laser welding, vibration welding, ultrasonic welding, hot press welding, hot plate welding, non-contact hot plate welding, or high frequency welding. When a thermosetting resin is used, the joining member 2 may be joined to the joining area R2 of the metal member 1 having the uneven portion 1b formed on the surface 1a by injection molding a resin material containing a thermosetting resin. Alternatively, for example, a resin material adjusted to a predetermined viscosity may be applied to the joining area R2, and then the joining member 2 may be joined to the joining area R2 by integral compression molding.

[0032] As shown in the side view of Fig. 3, the metal member 1 irradiated with the laser beam according to the first example of the scanning path has the joining member 2 joined to the joining area R2, which is the entirety of the laser irradiation area R1. Also, as shown in the side views of Fig. 4 and Fig. 5, the metal member 1 irradiated with the laser beam according to the second or third example of the scanning path has the joining member 2 joined to the joining area R2, which is a part of the laser irradiation area R1.

[0033] Through the above-described joining process, a joined body 10 is obtained in which the joining member 2 is joined to the joining area R2 of the metal member 1. In the joined body 10 thus obtained, the metal member 1 with the joining member 2 joined to the joining area R2 has a joining portion where the metal member 1 is joined to the joining member 2 and an unjoined portion where the metal member 1 is not joined to the joining member 2.

[0034] In the joined body 10 manufactured by the above-mentioned manufacturing method, the resin material constituting the joining member 2 fills the minute concave portions of the joined area R2, and the joined area R2 is joined to the joining member 2 by an anchor effect. In this way, by joining the joining member 2 to the joined area R2 of the metal member 1 having the concave portions 1b formed on the surface 1a, a joined body 10 with high adhesion between the metal member 1 and the joining member 2 and improved joining strength can be obtained.

[0035] Here, FIG. 6 is a plan view of a metal member and a side view of a joined body showing a comparative example of the scanning path of the laser beam. The arrow shown in the plan view of FIG. 6 indicates the scanning direction of the laser beam. As shown in the plan view of FIG. 6, in the comparative example, the scanning path of the laser beam is set for the joining area R2, which is the laser irradiation area R1, so as to move from the inner periphery side to the outer periphery side of the metal member 1. In the case of the scanning path shown in FIG. 6, the laser beam can be scanned so as to rotate along the circumferential direction from the scanning start position S4 to the scanning end position G4. Here, the scanning start position S4, which is the first irradiation position of the laser beam, is set to the center of the joining area R2 (laser irradiation area R1) where the innermost scanning line L8 is formed, and the scanning end position G4, which is the last irradiation position of the laser beam, is set to the outermost periphery of the joining area R2 (laser irradiation area R1) where the outermost scanning line L1 is formed. That is, the scanning start position S4 and the scanning end position G4 are set inside the joining area R2.

[0036] For example, the laser beam is first scanned in one direction along the circumferential direction from the scanning start position S4 to form a scanning line L8 in the welding area R2, and then shifted to the outside of the scanning line L8 so as to move away from the center of the welding area R2, and scanned in one direction along the circumferential direction again to form a scanning line L7 in the welding area R2. In this way, by irradiating the laser beam from the scanning start position S4 to the scanning end position G4 according to the scanning path shown in FIG. 6, the scanning lines L8, L7, L6, L5, L4, L3, L2, and L1 that go around in the circumferential direction are sequentially formed in the welding area R2. Then, after forming the scanning line L1 that is the most downstream in the scanning direction, the scanning of the laser beam is stopped at the scanning end position G4. By irradiating the welding area R2 with the laser beam according to the scanning path shown in FIG. 6, the scanning lines L1 to L8 are formed in the areas A1 to A8 that are adjacent to each other in the welding area R2.

[0037] Referring to an enlarged SEM image of a portion of region A8 of an actually manufactured metal member 1, it can be seen that an uneven portion 1b having a suitable uneven shape on the order of nm is formed in region A8. On the other hand, referring to an enlarged SEM image of a portion of region A1 of an actually manufactured metal member 1, it can be seen that a suitable uneven shape is not formed in region A1.

[0038] As shown in the side view of FIG. 6, the metal member 1 irradiated with the laser beam according to the comparative example of the scanning path has the joining member 2 joined to the joining area R2, which is the entire laser irradiation area R1. In the joined body 100 manufactured in this way, the resin material constituting the joining member 2 enters the concaves of the uneven shape of the joining area R2 formed by the irradiation of the laser beam, and the joining area R2 is joined to the joining member 2 by the anchor effect. However, when the joining area R2 is irradiated with the laser beam according to the comparative example of the scanning path, the scanning line L1 at the most downstream of the scanning direction of the laser beam becomes the scanning line of the outermost periphery of the joining area R2, so that the amount of metal particles 1p deposited in the outermost periphery area A1 where the scanning line L1 is formed is smaller than that of the other areas A2 to A8. Therefore, there is a problem that the joining strength of the metal member 1 to which the joining member 2 is joined may decrease in the outermost periphery of the joining area R2.

[0039] In contrast, in the laser irradiation process, when the laser beam is irradiated to the joining area R2 according to the first example of the scanning path (see FIG. 3), the scanning line L1 at the most downstream position in the scanning direction is located at the center inside the outermost periphery of the joining area R2. Therefore, a joined body 10a in which the joining strength at the outermost periphery of the joining area R2 of the metal member 1 to which the joining member 2 is joined is suppressed can be obtained. In addition, in the laser irradiation process, when the laser beam is irradiated to the laser irradiation area R1 according to the second example (see FIG. 4) or the third example (see FIG. 5) of the scanning path, the scanning line L1 at the most downstream position in the scanning direction is located at the unjoined portion outside the joining area R2. Therefore, a joined body 10b or a joined body 10c in which the joining strength at the outermost periphery of the joining area R2 of the metal member 1 to which the joining member 2 is joined is suppressed can be obtained.

[0040] Therefore, the bonded body 10 manufactured by the manufacturing method for the bonded body 10 according to the present embodiment can exhibit a bonding strength that does not easily crack at the boundary between the bonded portion and the unbonded portion, where stress caused by the action of external forces, temperature changes, etc. is concentrated.

[0041] The present disclosure is not limited to the above-mentioned embodiment, and can be appropriately modified within the scope of the present disclosure. For example, in the above-mentioned embodiment, the case where the molten metal evaporates to become metal vapor in the laser irradiation process is described as an example, but is not limited to this. In the laser irradiation process, the molten metal may be turned into plasma to become metal plasma. In this case, the metal plasma is released into the plasma atmosphere.

[0042] Furthermore, in the above embodiment, the scanning lines are straight lines, but the scanning lines may be curved lines instead of straight lines, or may be a combination of straight lines and curved lines.

[0043] In the above embodiment, as a second example of the scanning path of the laser beam, a scanning path is set in the laser irradiation range R1 including the welding range R2 so as to go from the inner periphery side to the outer periphery side of the metal member 1 when the scanning direction is the circumferential direction of the metal member 1, but the present invention is not limited to this. For example, in the laser irradiation range R1 including the welding range R2, a scanning path may be set so as to go from the outer periphery side to the inner periphery side of the metal member 1, as in the first example of the scanning path. Even with this configuration, the scanning line at the most downstream position in the scanning direction is disposed in the center, which is inside the outermost periphery of the welding range R2, so that a bonded body 10 can be obtained in which a decrease in the bonding strength at the outermost periphery of the bonding range R2 of the metal member 1 to which the bonding member 2 is bonded is suppressed. [Explanation of symbols]

[0044] 1 Metallic parts 1a surface 1b Uneven part 1p metal particles 2 Joining materials 10, 10a, 10b, 10c, 100 zygote A1~A9 area G1~G4 Scan end position L1~L9 scan lines R1 Laser irradiation range R2 Range to be joined S1~S4 Scan start position

Claims

1. a laser irradiation process in which a pulsed laser beam is irradiated onto a laser irradiation range set on a surface of a metal member to form an uneven portion having an uneven shape on the surface of the metal member, and metal particles generated due to the metal member being melted by the laser beam are deposited in an area adjacent to a scanning line irradiated with the laser beam and in an area of ​​the scanning line; A joining process of joining a joining member to a joining area which is at least a part of the laser irradiation area, A method for manufacturing a bonded body, in which, in the laser irradiation process, a scanning path of the laser beam is set so that the scanning line furthest downstream in the scanning direction of the laser beam is not a scanning line at the outermost periphery of the bonded area.

2. When the scanning direction is a circumferential direction of the metal member, The method for manufacturing a joint body according to claim 1 , wherein the scanning path is set with respect to the joining area so as to move from an outer periphery side to an inner periphery side of the metal member.

3. When the scanning direction is a circumferential direction of the metal member, The method for manufacturing a joined body according to claim 1 , wherein the scanning path is set in the laser irradiation area including the area to be joined so as to go from the outer periphery side to the inner periphery side or from the inner periphery side to the outer periphery side of the metal members.

4. When the scanning direction is a first direction along a surface of the metal member, 2. The method for manufacturing a bonded body according to claim 1, wherein the scanning path is set in the laser irradiation area including the bonded area so as to go from one side to the other side in a second direction perpendicular to the first direction.

Images