Method for joining dissimilar materials

Abstract

The present invention provides a method for easily joining joining members and members to be joined. [Solution] A method for joining dissimilar materials, namely a joining member and a member to be joined which is a different material, comprises the steps of: applying a surface treatment to the joining surface of the joining member; overlapping the joining member and the member to be joined; irradiating the surface of the joining member opposite to the joining surface with a laser under irradiation conditions that form a keyhole, thereby heating the member to be joined; and joining the joining member and the member to be joined.

Description

Technical Field

[0001] The embodiment relates to a method for joining dissimilar materials.

Background Art

[0002] As a method for joining dissimilar materials, a friction stir welding method or the like is known.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the method described in Patent Document 1 above, since it is necessary to apply a chemical to the joining member or apply a load to the joining member and the joined member, there is room for improvement in that the member is deformed and it takes time and effort.

[0005] An object of the embodiment is to provide a method capable of easily joining a joining member and a joined member.

Means for Solving the Problems

[0006] The joining method according to the embodiment is a method for joining dissimilar materials between a joining member and a joined member made of a dissimilar material, and includes a step of performing a surface treatment on a joining surface of the joining member, a step of overlapping the joining member and the joined member, a step of irradiating a laser under irradiation conditions in which a keyhole is formed on a surface of the joining member opposite to the joining surface to heat the joined member, and a step of joining the joining member and the joined member.

Brief Description of the Drawings

[0007] [Figure 1] It is a flowchart for explaining the procedure of the joining method according to the embodiment. [Figure 2] This is a schematic cross-sectional view illustrating the surface treatment process (S100) for the joining members. [Figure 3] This is a schematic cross-sectional view illustrating the overlapping process (S200) of the joining surfaces. [Figure 4] This is a schematic cross-sectional view illustrating the laser irradiation process (S300). [Figure 5] This is an enlarged schematic cross-sectional view of the bonding surface during the laser irradiation process (S300). [Figure 6] This is a schematic cross-sectional view illustrating the joining process (S400) of the joint surface. [Modes for carrying out the invention]

[0008] <Embodiment> Embodiments will be described below. Figure 1 is a flowchart illustrating the procedure of the joining method according to the embodiment. As shown in Figure 1, the joining method in this disclosure consists of a surface treatment step of the joining members (S100), an overlapping step of the joining surfaces (S200), a laser irradiation step (S300), and a joining step of the joining surfaces (S400), performed in order. Each step will be described in detail below.

[0009] Figure 2 is a schematic cross-sectional view illustrating the surface treatment process (S100) of the joining member. In the surface treatment step (S100) of the joining member, the joining surface 10a of the joining member 10 is subjected to surface treatment. As an example, in this embodiment, the joining member 10 is a metal, specifically aluminum, copper, iron, stainless steel, etc. The surface treatment is a cleaning treatment by laser processing, in which a laser L1 is irradiated onto the joining member 10. Specifically, on the joining member 10, the laser L1 is irradiated over the entire joining region R1 to be joined with the member to be joined 20 (see Figure 3) while moving in the direction of arrow A1. By doing so, irregularities are formed over the entire joining surface 10a in the joining region R1, making it possible to strengthen the joint through anchoring effect and chemical bonding. The irradiation conditions for the laser L1 in the surface treatment are a power density of 50 J / cm². 2More than 200J / cm 2 The following may also be used. Furthermore, the width of the surface irregularities may be 5 μm to 100 μm.

[0010] Figure 3 is a schematic cross-sectional view illustrating the overlapping process (S200) of the joining surfaces. In the overlapping process of the joining surfaces (S200), the joining surface 10a of the joining member 10 and the joining surface 20a of the member to be joined 20 are overlapped. The member to be joined 20 has a lower melting point than the joining member 10. For example, the member to be joined 20 is a resin, specifically CFRP (Carbon Fiber Reinforced Plastics) or PEEK (Poly Ether Ether Ketone).

[0011] Figure 4 is a schematic cross-sectional view illustrating the laser irradiation process (S300). In the laser irradiation process (S300), the laser L2 is irradiated from the irradiation surface 10b opposite to the joining surface 10a of the joining member 10 so that a keyhole H is formed in the joining member 10. The conditions for the formation of the keyhole H are, for example, a power density of 10 6 W / cm 2 The above conditions may also be used. By irradiating with laser L2 under these conditions, a part of the joining member 10 melts from the irradiated surface 10b side, and a keyhole H is formed in the direction of arrow A2 from the irradiated surface 10b.

[0012] Figure 5 is an enlarged schematic cross-sectional view of the bonding surface during the laser irradiation process (S300). As shown in an enlarged view in Figure 5, a fine gap D is formed between the joining surface 10a of the joining member 10 and the joining surface 20a of the member to be joined 20. In this embodiment, by irradiating the joining member 10 with a laser L2 in such a way that a keyhole is generated, a back wave (a bulge formed on the surface opposite to the laser irradiation surface) W is formed on the joining surface 10a of the joining member 10, and the member to be joined 20 is heated. The member to be joined 20 has a lower melting point than the joining member 10 and melts upon irradiation with the laser L2.

[0013] FIG. 6 is a schematic cross-sectional view for explaining the joining process (S400) of the joining surface. In the joining process (S400) of the joining surface, the heat of the joining member 10 heated and melted by the irradiation of the laser L2 is conducted to the joined member 20, and the joined member 20 is heated and melted. Thereby, the joining surface 10a of the joining member 10 and the joining surface 20a of the joined member 20 are joined.

[0014] (Parentheses) According to the embodiment described above, the joining method in the present disclosure is a joining method between the joining member 10 and the joined member 20 which is a different material, and includes a step of performing a surface treatment on the joining surface 10a of the joining member 10, a step of overlapping the joining member 10 and the joined member 20, and irradiating the irradiation surface 10b on the opposite side of the joining surface 10a of the joining member 10 with a laser under irradiation conditions in which a keyhole is formed to heat the joined member 20, and a step of joining the joining member 10 and the joined member. With such a configuration, it is possible to join the joining member 10 and the joined member 20 in a simple manner without applying weight to the joining member 10 and the joined member 20 and without using chemicals or the like for joining, and without deforming the members.

[0015] Also, in the step of performing the surface treatment, a cleaning treatment is performed on the joining surface 10a. By doing so, it is possible to remove organic substances such as carbon adhering to the joining surface 10a and activate the joining surface 10a.

[0016] Also, in the cleaning treatment, irregularities are formed on the joining surface by laser processing. By doing so, it is possible to firmly join the joining member 10 and the joined member 20 by the anchor effect generated by the irregularities on the joining surface.

[0017] Further, the joined member 20 has a lower melting point than the joining member 10, and in the heating step, the joined member 20 is heated to a temperature not lower than the melting point and not higher than the boiling point. By doing so, the joined member 20 can be melted by laser irradiation of the joining member 10, and the joining member 10 and the joined member 20 can be joined together.

[0018] Further, the joining member may be made of metal and the joined member may be made of resin. With such a configuration, the technical idea of the present disclosure can be specifically applied to obtain the above-described effects in joining different materials.

[0019] <Other Embodiments> As described above, the embodiments of the present disclosure have been described, but the present disclosure is not limited to the above. For example, in the above embodiment, in S100, as the surface treatment of the joining surface 10a of the joining member 10, unevenness formation by laser processing is performed, but the present disclosure is not limited to this aspect. For example, plasma treatment may be performed on the joining surface 10a of the joining member 10 as the surface treatment. Further, surface treatment other than cleaning treatment may be performed.

[0020] As described above, some embodiments of the present invention have been described, but these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the gist of the invention. These embodiments and their modifications are included in the scope and gist of the invention, and are also included in the scope of the invention described in the claims and its equivalents.

[0021] The present invention includes the following aspects. (Appendix 1) A method for joining different materials of a joining member and a joined member which is a different material, comprising: a step of performing a surface treatment on the joining surface of the joining member; a step of overlapping the joining member and the joined member; A step of heating the member to be joined by irradiating the surface of the joining member opposite to the joining surface with a laser under irradiation conditions that form a keyhole, A joining method comprising the steps of joining the joining member and the member to be joined. (Note 2) The joining method described in Appendix 1, wherein the step of applying the surface treatment is to apply a cleaning treatment to the joining surface. (Note 3) The joining method described in Appendix 2, wherein the cleaning process involves forming irregularities on the joining surface by laser processing. (Note 4) The joining method described in Appendix 3, wherein the cleaning process involves forming irregularities on the entire joining surface by laser processing. (Note 5) The member to be joined has a lower melting point than the joining member. The joining method according to Appendix 1, wherein the heating step involves heating the members to be joined above their melting point and below their boiling point. (Note 6) The joining method according to Appendix 5, wherein the joining member is made of metal and the member to be joined is made of resin. [Explanation of Symbols]

[0022] 10: Joining member, 10a: Joining surface, 10b: Irradiation surface, 20: Joined member, 20a: Joining surface

Claims

1. A method for joining dissimilar materials, namely a joining member and a member to be joined, which is made of a different material, A step of applying a surface treatment to the joining surface of the aforementioned joining member, A step of overlapping the joining member and the member to be joined, A step of heating the member to be joined by irradiating the surface of the joining member opposite to the joining surface with a laser under irradiation conditions that form a keyhole, A step of joining the joining member and the member to be joined, A joining method comprising the following features.

2. The joining method according to claim 1, wherein the step of applying the surface treatment is to apply a cleaning treatment to the joining surface.

3. The joining method according to claim 2, wherein the cleaning process involves forming irregularities on the joining surface by laser processing.

4. The joining method according to claim 3, wherein the cleaning process involves forming irregularities on the entire joining surface by laser processing.

5. The member to be joined has a lower melting point than the joining member. The joining method according to claim 1, wherein the heating step involves heating the members to be joined above their melting point and below their boiling point.

6. The joining method according to claim 5, wherein the joining member is made of metal and the member to be joined is made of resin.

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