Joining method of aluminum materials and joined body of aluminum materials

Abstract

To provide: a joining method of aluminum materials which can, when joining a member having a welded part which becomes a discontinuous part and another member while accompanying plastic flow due to frictional heat, join the members with high strength without influencing the welded part; and a joined member of aluminum materials.SOLUTION: A joining method of aluminum materials comprises joining a planer first member 21 formed by extrusion molding of aluminum material and a second member 23 made of aluminum material. The first member 21 partially has a welded part Sj formed along the thickness direction and the extrusion direction, which was diffusion joined after separating by plastic flow during extrusion molding and associating again. The second member 23 is rotated while pressing a fastening member 10 or a friction stir welding tool against an overlapping part O where the second member 23 is overlapped with a non-welded portion where at least the welded part Sj of the first member 21 is not formed, and the first member 21 and the second member 23 are softened and stir joined by frictional heat generated.SELECTED DRAWING: Figure 11

Description

[Technical field]

[0001] The present invention relates to a method for joining aluminum materials and a joined body of aluminum materials. [Background technology]

[0002] There has been a demand for improving the safety of vehicle occupants in vehicles, and for this purpose, the strength of the vehicle body has been improved. On the other hand, against the background of the worsening of the problem of global warming, the movement to improve the fuel efficiency of automobiles is accelerating. It is known that reducing the weight of the vehicle body is effective in improving fuel efficiency. In the context of the above, the development of vehicles (including electric vehicles, hybrid vehicles, etc.) that run on electricity is progressing. In fields other than automobiles, the development of devices such as self-propelled robots is also progressing. Battery systems mounted on such vehicles or devices generally have a configuration in which a large number of batteries (cells, battery cells) are housed in a battery tray. Thus, attempts have been made to reduce the weight of vehicles by making this battery tray out of aluminum material (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2009-105007 A Summary of the Invention [Problem to be solved by the invention]

[0004] In the case of automotive parts such as the battery tray described above, a desired shape can be easily produced by combining multiple extruded panels. In particular, in the case of extruded panels made of aluminum material, even complex cross-sectional shapes, such as those having a hollow portion within the plate material, can be produced with high efficiency by, for example, the porthole extrusion method.

[0005] However, when forming by the porthole extrusion method, multiple billets (molding materials) are extruded as separate streams while undergoing plastic flow in the extrusion die. The streams reunite in the extrusion die to form a diffusion-bonded joint surface. The welded part having such a joint surface is also a discontinuous part in the base material. Therefore, if plastic deformation occurs again at the interface of the joint surface and around the interface, there is a high possibility of forming unexpected imperfections (defects). For example, friction stir welding of an area including a welded part may cause voids or, depending on the situation, cracks. In addition, in drill screw joining, in which thread rolling is performed by plastic flow under frictional heat, the base materials are joined across the welded part, causing the same problem.

[0006] Therefore, an object of the present invention is to provide a method for joining aluminum materials and a joined body of aluminum materials that can join components having a welded portion that is discontinuous to another component with high strength without affecting the welded portion when joining the components together accompanied by plastic flow due to frictional heat. [Means for solving the problem]

[0007] The present invention comprises the following configurations. (1) A method for joining aluminum materials, which joins a first member formed by extruding an aluminum material made of aluminum or an aluminum alloy to a second member made of the aluminum material, the first member has a welded portion in a part thereof, the welded portion being a joint surface formed along a thickness direction and an extrusion direction, the joint surface being branched by plastic flow during extrusion molding and then reunited to be diffusion-joined; The second member is overlapped at least on a non-welded portion of the first member where the welded portion is not formed to form an overlapping portion; a rod-shaped fastening member for joining is pressed against the overlapping portion and rotated, and the fastening member for joining is penetrated into the overlapping portion while causing plastic flow of the overlapping portion by generated frictional heat, thereby joining the first member and the second member; A method for joining aluminum materials. (2) A method for joining aluminum materials, which joins a first member formed by extruding an aluminum material made of aluminum or an aluminum alloy to a second member made of the aluminum material, the first member has a welded portion in a part thereof, the welded portion being a joint surface formed along a thickness direction and an extrusion direction, the joint surface being branched by plastic flow during extrusion molding and then reunited to be diffusion-joined; The second member is overlapped at least on a non-welded portion of the first member where the welded portion is not formed to form an overlapping portion; While pressing a tip of a friction stir welding tool against the overlapping portion and rotating it, the tip is moved along the interface between the first member and the second member of the overlapping portion to friction stir weld the first member and the second member of the overlapping portion. A method for joining aluminum materials. (3) A method for joining aluminum materials, which joins a first member formed by extruding an aluminum material made of aluminum or an aluminum alloy to a second member made of the aluminum material, The first member has a welded portion in a part thereof, in which a joining surface that is branched by plastic flow during extrusion molding and then reunites and diffusion-joined is formed in a width direction perpendicular to a thickness direction and an extrusion direction, and along the extrusion direction; forming an overlapping portion by butting the second member against an end surface of the first member along the extrusion direction; A tip of a friction stir welding tool is pressed against the overlapping portion and rotated while moving along the interface between the first member and the second member of the overlapping portion to friction stir weld the overlapping portion in the thickness direction within a range not exceeding the welded portion, from one plate surface side and the other plate surface side of the first member, respectively. A method for joining aluminum materials. (4) A joined body of aluminum materials, which joins a first member formed by extruding an aluminum material made of aluminum or an aluminum alloy to a second member made of the aluminum material, the first member has a welded portion in a part thereof, the welded portion being a joint surface formed along a thickness direction and an extrusion direction, the joint surface being branched by plastic flow during extrusion molding and then reunited to be diffusion-joined; a rod-shaped fastening member for joining is provided at an overlapping portion between a non-welded portion of the first member where the welded portion is not formed and the second member, penetrating the first member and the second member, and the first member and the second member are joined together; Aluminum material joint. (5) A joined body of aluminum materials, in which a first member formed by extruding an aluminum material made of aluminum or an aluminum alloy and a second member made of the aluminum material are joined together, the first member has a welded portion in a part thereof, the welded portion being a joint surface formed along a thickness direction and an extrusion direction, the joint surface being branched by plastic flow during extrusion molding and then reunited to be diffusion-joined; A friction stir welded portion that joins the first member and the second member is formed at an overlapping portion between a non-welded portion of the first member where the welded portion is not formed and the second member, Aluminum material joint. (6) A joined body of aluminum materials, in which a first member formed by extruding an aluminum material made of aluminum or an aluminum alloy and a second member made of the aluminum material are joined together, The first member has a welded portion in a part thereof, in which a joining surface that is branched by plastic flow during extrusion molding and then reunites and diffusion-joined is formed in a width direction perpendicular to a thickness direction and an extrusion direction, and along the extrusion direction; At the overlapping portion where the second member is butted against the end surface along the extrusion direction of the first member, friction stir welded portions that join the first member and the second member are formed from one plate surface side and the other plate surface side of the first member in the thickness direction without exceeding the welded portion, Aluminum material joint. Effect of the Invention

[0008] According to the present invention, when a component having a welded portion that becomes a discontinuous portion is joined to another component using plastic flow caused by frictional heat, the components can be joined with high strength without affecting the welded portion. [Brief description of the drawings]

[0009] [Figure 1] FIG. 1 is a cross-sectional view of a porthole die taken along the extrusion direction. [Diagram 2] FIG. 2 is a front view of the porthole die as seen from the male die side. [Diagram 3] FIG. 3 is an exploded perspective view of the porthole die taken along the extrusion direction. [Figure 4] FIG. 4 is a schematic front view of an extrusion material extruded by porthole extrusion. [Diagram 5] FIG. 5 is a perspective view of an extruded panel extruded by porthole extrusion. [Figure 6] FIG. 6 is a front view of a portion of an extruded panel illustrating a welded portion formed in the extruded panel. [Figure 7] FIG. 7 is a front view of a portion of an extruded panel illustrating a welded portion formed in the extruded panel. [Figure 8] FIG. 8 is a side view of a screw used in FDS type joining. [Figure 9] FIG. 9 is a process explanatory diagram showing, in stages (A) to (E), how a first member and a second member are joined by the FDS method. [Figure 10] FIG. 10 is a cross-sectional view illustrating a case where a first member and a second member having a welded portion are joined by the FDS method. [Figure 11] FIG. 11 is a cross-sectional view of a bonded body in which a first member and a second member having a welded portion are bonded by the FDS method. [Figure 12] FIG. 12 is a perspective view showing how a first member and a second member are joined by the FSW method. [Figure 13]FIG. 13 is a perspective view of a joint in which a first member, which is an extruded panel having a welded portion, and a second member are joined by the FSW method. [Figure 14] FIG. 14 is a front view of a portion of the joined body shown in FIG. [Figure 15] FIG. 15 is a front view of a portion of a joint in which a first member made of an extruded panel having a welded portion and a second member having no welded portion are joined by the FSW method. [Figure 16] FIG. 16 is a cross-sectional view showing how a first member and a second member overlapped with each other in the thickness direction are joined by the FSW method. [Figure 17] FIG. 17 is a plan view that shows a schematic diagram of a first member in which a marking portion is provided in a part of a welded portion. [Figure 18] FIG. 18 is a front view of the first member and the second member, showing a state in which the first member having a step formed in the thickness direction and the second member are superimposed on each other. [Figure 19] FIG. 19 is a cross-sectional photograph of a bonded body in which a first member and a second member were bonded in Test Example 1. As shown in FIG. [Figure 20] FIG. 20 is a cross-sectional photograph of a bonded body in which the first member and the second member were bonded in Test Example 3. [Figure 21] FIG. 21 is a cross-sectional photograph of a bonded body in which the first member and the second member were bonded in Test Example 6. [Figure 22] FIG. 22 is a cross-sectional photograph of a bonded body in which the first member and the second member were bonded in Test Example 7. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. The method for joining aluminum materials according to the present invention is a method for joining a plate-shaped first member having a welded portion and formed by extruding an aluminum material made of aluminum or an aluminum alloy, to a second member made of an aluminum material.

[0011] (Porthole Extrusion) Here, the porthole extrusion molding in which a welded portion is formed will be described. Fig. 1 is a cross-sectional view of a porthole die 100 along the extrusion direction X. Fig. 2 is a front view of the porthole die 100 as viewed from the male die 101 side. Fig. 3 is an exploded perspective view of the porthole die 100 as viewed along the extrusion direction X.

[0012] As shown in Figures 1 to 3, a porthole die 100 used in porthole extrusion molding is configured by combining a male die 101 and a female die 103. The male die 101 has a plurality of extrusion holes 105. The male die 101 also has a mandrel 107 at its center that protrudes toward the female die 103. The female die 103 has a through hole 109 at its center in which the mandrel 107 of the male die 101 is placed, and a gap G is formed between the mandrel 107 and the through hole 109.

[0013] In extrusion molding using this porthole die 100, the aluminum material AL forced from the male die 101 side in the extrusion direction X is divided and fed into each extrusion hole 105 in the male die 101, and is forced into these extrusion holes 105 while undergoing plastic flow. Thereafter, the aluminum material AL forced into each extrusion hole 105 is forced into a gap G between the mandrel 107 and the through hole 109. At this time, the divided aluminum materials AL are reunited and solid-phase bonded to each other, and an integrated extrusion material ALe is formed.

[0014] 4 is a schematic front view of the extrusion material ALe extruded by porthole extrusion. In the extrusion material ALe extruded by porthole extrusion, the solid-state welded portion inside the porthole die 100 appears as a linear welded portion Sj in a cross-sectional view. The welded portion Sj changes depending on the position and direction in which the aluminum material AL is supplied to the porthole die 100.

[0015] FIG. 5 is a perspective view of an extruded panel 110 extruded by porthole extrusion. FIGS. 6 and 7 are front views of a portion of the extruded panel 110 illustrating the welded portion Sj formed in the extruded panel 110. The extruded panel 110 shown in FIG. 5 is an extrusion product made of aluminum material, and is, for example, a member constituting a battery tray mounted on a vehicle, a self-propelled robot, or the like. A plurality of hollow portions 113 continuous in the extrusion direction are formed in the center of the thickness direction of the extruded panel 110. Solid ribs 115 are formed between the hollow portions 113 of the extruded panel 110. When such an extruded panel 110 is molded by porthole extrusion, for example, the welded portion Sj is formed in the rib 115.

[0016] When the aluminum material AL is supplied from a plurality of locations separated from each other, as shown in Fig. 6, the welded portion Sj is formed along the thickness direction (vertical direction in Fig. 6) and extrusion direction (depth direction in Fig. 6) of the rib 115, or as shown in Fig. 7, the welded portion Sj is formed along the plate surface direction (horizontal direction in Fig. 7) and extrusion direction (depth direction in Fig. 7) at the center position of the thickness direction of the rib 115. That is, the extruded panel 110 has a welded portion Sj in a part thereof, which is a joint surface where the flow is diverged by the plastic flow during extrusion molding and then reunited and diffusion-joined. The welded portion Sj may be formed along the thickness direction and extrusion direction as shown in Fig. 6, or may be formed along the width direction perpendicular to the thickness direction and extrusion direction and along the extrusion direction as shown in Fig. 7.

[0017] Incidentally, in an extrusion molded product having a welded portion Sj, the welded portion Sj is a discontinuous portion with respect to the base material, so if the joint surface of the welded portion Sj or its surroundings is subjected to further plastic deformation, there is a risk that unexpected imperfections such as voids or cracks will be formed.

[0018] In this method for joining aluminum materials, an extrusion product (first member) formed by porthole extrusion is joined to another second member while suppressing the formation of the above-mentioned imperfections. For the joining, a flow drill screw (hereinafter referred to as FDS, where FDS is a registered trademark) method or a friction stir welding (hereinafter referred to as FSW) method can be used. The FDS method is a method in which a screw, which is a rod-shaped fastening member for joining, is screwed in and fastened while performing thread rolling by plastic flow, and the FSW method is a method in which the first member and the second member are softened by frictional heat using a friction stir welding tool and friction stir welded. Below, a specific joining procedure for the first member and the second member based on these joining methods will be described.

[0019] (FDS method bonding) 8 is a side view of a screw 10 used in FDS-type joining. The screw (fastening member for joining) 10 used in FDS-type joining has a shaft portion 13 and a head portion 15 provided at the base end of the shaft portion 13. The shaft portion 13 has a shaft tip portion 17 and a threaded portion 19. The tip of the shaft tip portion 17 has a pointed shape, and the threaded portion 19 is formed with a screw thread 19a. The head portion 15 has a shape for fastening, such as a hexagonal hole 15a for applying a rotational force to the screw 10.

[0020] 9 is a process explanatory diagram showing, in stages, how a first member 21 and a second member 23 are joined by the FDS method. The joining process by the FDS method basically includes the following steps [1] to [5]. [1] As shown in Fig. 9(A), the first member 21 and the second member 23 are overlapped in the plate thickness direction, and the shaft tip portion 17 of the shaft portion 13 of the screw 10 is brought into contact with the first member 21. In this state, the screw 10 is rotated.

[0021] [2] As shown in Fig. 9(B), the screw 10 is rotated at high speed and an axial load is applied to press the tip of the screw 10 against the first member 21. As a result, the first member 21 and the second member 23 are heated by frictional heat, and the axial tip portion 17 of the screw 10 is pressed into the first member 21 and the second member 23 that have been softened by the heat.

[0022] [3] As shown in (C) of Figure 9, when the shank tip portion 17 of the screw 10 is inserted into the first member 21 and the second member 23, the softened first member 21 and second member 23 flow around the shank portion 13 of the screw 10 and form a cylindrical joint 25.

[0023] [4] As shown in Fig. 9(D) , the screw 10 is pushed into the first member 21 and the second member 23 up to the threaded portion 19, and the rotation of the screw 10 is decelerated and the load is reduced. By this deceleration of the screw 10 and reduction of the load, the thread 19a of the threaded portion 19 forms a female thread 25a in the cylindrical joint 25 of the first member 21 and the second member 23.

[0024] [5] As shown in Fig. 9(E), while rotating the screw 10, the head 15 of the screw 10 is moved in the axial direction until the back surface of the head 15 of the screw 10 abuts against the first member 21, and the screw 10 is pressed into the first member 21 and the second member 23. As a result, the material of the first member 21 flows into the groove 15b formed in the head 15 of the screw 10 by plastic flow, and the screw 10 is fastened to the first member 21 and the second member 23. In this way, the overlapping first member 21 and second member 23 are joined by the screw 10. In this specification, pressing the screw 10 while rotating it to the state shown in Fig. 9(E) is referred to as "driving" the screw 10.

[0025] According to the above-mentioned FDS method, the screw 10 itself drills holes in the first member 21 and the second member 23, so there is no need to drill pilot holes in the first member 21 and the second member 23. Moreover, since drilling is sufficient from one side of the first member 21 and the second member 23, workability is improved. In addition, the screw 10 can be removed after installation to separate the first member 21 and the second member 23, improving the recyclability of each member.

[0026] Incidentally, as described above, when the first member 21 is a porthole extrusion molded product, if the joining surface of the welded portion Sj of this first member 21 or its periphery is subjected to further plastic deformation, there is a risk of unexpected imperfections such as voids or cracks being formed. Therefore, when joining the first member 21 and the second member 23 by the FDS method, it is recommended to drive the screw 10 as follows.

[0027] Fig. 10 is a cross-sectional view illustrating a case where a first member 21 having a welded portion Sj and a second member 23 are joined by the FDS method. Fig. 11 is a cross-sectional view of a joined body 27 in which a first member 21 having a welded portion Sj and a second member 23 are joined by the FDS method.

[0028] The first member 21 and the second member 23 are preferably made of an aluminum alloy such as 6000 series or 7000 series, but may be made of other aluminum alloys. The first member 21 is, for example, a hollow material extruded from an aluminum material by the above-mentioned porthole extrusion molding. Since die-cast aluminum material is prone to burrs, the second member 23 is preferably made of an aluminum wrought material. Furthermore, since the second member 23 requires strength during joining, it is preferably made of an extruded material like the first member 21.

[0029] As shown in Fig. 10, the first member 21 and the second member 23 are overlapped. The first member 21 shown in Fig. 10 is made of an extruded panel 110 in which welded parts Sj along the thickness direction and extrusion direction are formed on ribs 115. The second member 23 is made of a plate material. Here, the parts of the first member 21 other than the parts where the welded parts Sj are formed are referred to as "non-welded parts".

[0030] The above-mentioned overlapping of the first member 21 and the second member 23 is performed by overlapping the non-welded portion with the second member 23 to form an overlapping portion O where the first member 21 and the second member 23 are joined. In the case shown in Fig. 10, the entire surfaces of the plates overlap because plate-shaped members are overlapped, but depending on the shape of each member, only a portion of the surface of one member may overlap the other member. Therefore, here, the overlapping portion of the first member 21 and the second member 23 is referred to as the "overlapping portion O."

[0031] In this overlapping portion O, at least the shaft portion 13 of the screw 10 is set at a position where it does not interfere with the welded portion Sj. For example, when the outer diameter of the shaft portion 13 of the screw 10 is D [mm], the welded portion Sj is set so as not to enter the range of the shaft portion 13 of this outer diameter D [mm]. In addition, in the overlapping portion O, the thickness of the second member 23 at the portion where it is joined to the first member 21 is preferably 1.0 mm or more and 5.0 mm or less in order to obtain an appropriate joint strength. By setting the thickness of the second member 23 to 5.0 mm or less, the shaft portion 13 of the screw 10 can be reliably penetrated into the second member 23 while maintaining the rigidity of the joint between the first member 21 and the second member 23.

[0032] Next, the screw 10 is rotated around its axis while being pressed against the overlapping portion O of the first member 21 and the second member 23. The frictional heat generated by this softens the non-welded portion of the first member 21 and the second member 23. Then, as shown in FIG. 11, the axial tip portion 17 of the screw 10 is pressed into the softened region while being rotated, and the shaft portion 13 penetrates the overlapping portion O. Then, the threads 19a of the shaft portion 13 of the screw 10 are rolled on the overlapping portion O side, and the first member 21 and the second member 23 are joined by engaging both threads. In this way, a joined body 27 in which the first member 21 and the second member 23 are joined by the screw 10 is obtained without causing stirring such as plastic flow in the welded portion Sj of the first member 21.

[0033] According to the above-described method for joining aluminum materials, the second member 23 is overlapped on a non-welded portion of the first member 21 where no welded portion Sj is formed, and the first member 21 and the second member 23 are joined together in the region where no welded portion Sj exists with the screw 10. Therefore, the first member 21 and the second member 23 can be joined together with high strength without affecting the welded portion Sj, which is the discontinuous portion of the first member 21.

[0034] (FSW method) 12 is a perspective view showing how the first member 21 and the second member 23 are joined by the FSW method. A friction stir welding tool 30 used in the FSW method has a main body 31 and a probe 33. The main body 31 is formed in a columnar shape, and the probe 33 is provided so as to protrude in the axial direction from the center of the tip surface of the main body 31. The friction stir welding tool 30 is rotated in one direction R by a drive source such as a rotary drive motor (not shown).

[0035] In the joining by the FSW method, for example, the first member 21 and the second member 23 are butted against each other, and the friction stir welding tool 30 is rotated while pressing the tip of the probe 33 against the butted portion to apply pressure. This generates frictional heat to soften the butted portion. Then, the tip of the probe 33 is pressed into the softened butted portion, and the friction stir welding tool 30 is moved along the butted portion while the shoulder surface 34 of the tip of the rotating main body 31 is brought into contact with the butted portion. Through the above procedure, the first member 21 and the second member 23 are softened and stirred by the frictional heat generated between the probe 33 and the shoulder surface 34 of the friction stir welding tool 30. Then, a friction stir welded portion B is formed at the butted portion between the first member 21 and the second member 23, and the first member 21 and the second member 23 are joined to each other.

[0036] Even in this FSW method, if the joining surface of the welded part Sj or its periphery is subjected to another plastic deformation, there is a risk of unexpected imperfections such as voids or cracks being formed. Therefore, when joining the first member 21 and the second member 23 by the FSW method, it is preferable to perform friction stir welding as follows.

[0037] Fig. 13 is a perspective view of a joined body 27 in which a first member 21 made of an extruded panel 110 having a welded portion Sj and a second member 23 are joined by the FSW method. Fig. 14 is a front view of a portion of the joined body 27 shown in Fig. 13.

[0038] As shown in Figure 13, when the first member 21 and the second member 23 are joined by butting their end faces together, if the welded portion Sj is formed at the center position in the plate thickness direction in the region of the rib 115 along the plate surface direction (direction perpendicular to the thickness direction and the extrusion direction) and the extrusion direction, respectively, as shown in Figure 14, the members are joined together without stirring the welded portion Sj.

[0039] Specifically, the end faces of the first member 21 and the second member 23 along the extrusion direction are butted against each other to form an overlapping portion O. The overlapping portion O at this time becomes the end face 21a of the first member 21 and the end face 23a of the second member 23 that are butted against each other, as shown in FIG. 14. In this overlapping portion O, the tip of the friction stir welding tool 30 is pressed against one plate surface of the first member 21 (for example, the upper plate surface 21b in FIG. 14) and one plate surface of the second member 23 (for example, the upper plate surface 23b in FIG. 14) while rotating and moving in the plate surface direction along the overlapping portion O. As a result, one plate surface 21b, 23b side of the overlapping portion O between the first member 21 and the second member 23 is friction stir welded. At this time, the friction stir by the friction stir welding tool 30 is limited to a range not exceeding each welded portion Sj of the first member 21 and the second member 23.

[0040] The tip of the friction stir welding tool 30 is pressed against the first member 21 and the second member 23 that have been friction stir welded from one plate surface 21b, 23b side, and is rotated and moved in the plate surface direction along the overlapping portion O from the other plate surface 21c, 23c side on the opposite side. This causes the other plate surface 21c, 23c side of the overlapping portion O of the first member 21 and the second member 23 to be friction stir welded. At this time, too, the friction stirring by the friction stir welding tool 30 is limited to a range that does not go beyond the welded portion Sj of the first member 21 and the second member 23.

[0041] As a result, a joint 27 of the first member 21 and the second member 23 is obtained in which the friction stir welded portion B is formed from one plate surface 21c and the other plate surface 23c in the overlapping portion O of the first member 21 and the second member 23 within a range not exceeding the welded portion Sj. In addition, it is preferable to perform the friction stir welding by arranging the first member 21 and the second member 23 side by side on a flat base and performing the friction stir welding from one plate surface 21b, 23b side, and then inverting the first member 21 and the second member 23 on the base and performing the friction stir welding from the other plate surface 21c, 23c side. According to this, the warp generated when performing the friction stir welding from one side is eliminated when performing the friction stir welding from the other side, and finally a flat joint is obtained.

[0042] Furthermore, the above example is a case where the welded portion Sj exists on both the first member 21 and the second member 23, but friction stir welding may be performed in the same manner even when the welded portion Sj exists on only one of the members. 15 is a front view of a portion of a joined body 27 in which a first member 21 made of an extruded panel 110 having a welded portion Sj and a second member 24 without a welded portion Sj are joined by the FSW method. In this case, the first member 21 has a welded portion Sj formed in the center position in the plate thickness direction along the plate surface direction and the extrusion direction. On the other hand, the second member 24 is made of a plate material without a welded portion Sj.

[0043] When the first member 21 and the second member 24 are joined by butting the end faces 21a, 24a against each other, similar to the case shown in Fig. 14 described above, a friction stir welding part B is formed from one plate surface 21b, 24b and the other plate surface 21c, 24c by the friction stir welding tool 30 within an area not exceeding the welded part Sj of the first member 21. As a result, the friction stir welding part B is formed within an area not affecting the welded part Sj at the overlapping part O, and a joined body 27 of the first member 21 and the second member 24 is obtained.

[0044] According to the above-described joining method, it is possible to obtain a joined body 27 in which the first member 21 and the second members 23, 24 are joined with high strength without affecting the welded portion Sj which becomes a discontinuous portion.

[0045] 16 is a cross-sectional view showing how a first member 21 and a second member 23 overlap each other in the thickness direction are joined by the FSW method. When the first member 21, in which a welded portion Sj along the plate thickness direction is formed on the rib 115, and the second member 23 made of a plate material are joined by overlapping them in the plate thickness direction, the second member 23 is first overlapped on a non-welded portion of the first member 21 to form an overlapping portion O.

[0046] The friction stir welding tool 30 is rotated while pressing a tip (probe 33, shoulder surface 34) against the overlapping portion O, thereby friction stir welding the first member 21 and the second member 23. As a result, a friction stir welded portion is formed that penetrates the first member 21 and the second member 23 without affecting the welded portion Sj, and the first member 21 and the second member 23 can be joined with high strength.

[0047] <Indication of welded part position> In both the FDS and FSW methods, it is important to avoid the welded parts Sj when joining so as not to affect the welded parts Sj through plastic flow, etc., but generally, the welded parts Sj appear as faint lines on the surface of the parts, and it can be difficult to always accurately identify their positions. Therefore, by providing a marking area at the position of the welded parts Sj, it becomes easier to identify the welded parts Sj, and it becomes easier for workers to work while avoiding the positions of the welded parts Sj.

[0048] 17 is a plan view showing a first member 21 having a marking portion M provided at a part of a welded portion Sj. For example, since the welded portion Sj is generated in the first member 21 extrusion-molded by porthole extrusion molding, the marking portion M is provided at the position of the welded portion Sj. This makes it possible to easily grasp the position of the welded portion Sj of the first member 21 by checking the marking portion M when joining the first member 21. This improves workability when joining the first member 21 to another member (for example, the above-mentioned second member 23) at a position away from the marking portion M.

[0049] The marking portion M may be any portion that allows the position of the welded portion Sj to be confirmed, and may be provided, for example, at one location on the welded portion Sj or may be provided continuously along the welded portion Sj. The marking portion M may be a shape characteristic portion including any of a recess, a protrusion, and a step, or may be a printed layer formed by an appropriate printing method.

[0050] FIG. 18 is a front view of the first member 21 and the second member 23, showing a state in which the first member 21 having a step formed in the thickness direction and the second member 23 are superimposed on each other. When a step is formed in the first member 21 in the thickness direction by porthole extrusion molding or the like, a welded portion Sj is likely to be formed at the step. By utilizing this, the step can also be used as the marking portion M. In other words, when an extrusion-molded product having a step is molded by porthole extrusion molding, if an aluminum material is supplied from a position away from the step in the mold, a meeting surface of the aluminum material is likely to be formed at the step. Therefore, the welded portion Sj is considered to be formed at the step portion, and the step is used as the marking portion M representing the welded portion Sj.

[0051] The above-mentioned joining procedure is a procedure in which the first member 21 and the second member 23 are joined while avoiding the welded portion Sj, and the joining position P where each member 21, 23 is joined by the FDS method or the FSW method is located away from the welded portion Sj, but is not limited to this. For example, the joining position P of the first member 21 and the second member 23 may be determined in advance at the design stage, and the extrusion molding conditions may be determined later so that the welded portion Sj when extruding the first member 21 is located away from the determined joining position. In other words, the meeting position of the aluminum material is adjusted so that the welded portion Sj is located at a position away from the set joining position P. A well-known method such as changing the supply position of the aluminum material can be used to adjust the meeting position. EXAMPLES

[0052] [First test] The first and second members overlapped in the thickness direction were joined by the FDS method based on the above-mentioned joining method for aluminum materials, and the joining state of the joint was evaluated. In addition, screws were driven into the overlapped first and second members from the first member side. The evaluation was performed for the following test examples 1 to 5.

[0053] <Test piece> (A1) Test Example 1 First component: 6000 series aluminum alloy, T5 treatment, plate thickness 2.0 mm Second component: 6000 series aluminum alloy, T5 treatment, plate thickness 2.0 mm (A2) Test Example 2 First component: 7000 series aluminum alloy, T7 treatment, plate thickness 2.0 mm Second component: 7000 series aluminum alloy, T7 treatment, plate thickness 2.0 mm (A3) Test Example 3 First component: 6000 series aluminum alloy, T5 treatment, plate thickness 2.0 mm Second component: 6000 series aluminum alloy, T5 treatment, plate thickness 2.0 mm (The second member has a step of 2.0mm to 2.4mm in thickness near the welded part Sj.) (A4) Test Example 4 First component: 6000 series aluminum alloy, T5 treatment, plate thickness 2.0 mm Secondary component: 6000 series aluminum alloy, T5 treatment, plate thickness 5.5 mm (A5) Test Example 5 First component: 7000 series aluminum alloy, T5 treatment, plate thickness 2.0 mm Secondary component: Aluminum die-cast material, thickness 4.5 mm (The first component has a step of 2.0mm to 2.4mm in thickness near the welded part Sj.)

[0054] <Evaluation Results> (A1) Test Example 1 In test example 1, as shown in Figure 19, a screw 10 was driven into a first member 21 and a second member 23 that were stacked on top of each other in the plate thickness direction, and a joint 27 in which the first member 21 and the second member 23 were fastened was obtained.

[0055] (A2) Test Example 2 In test example 2, a screw was driven into the first and second members that were stacked on top of each other in the plate thickness direction to obtain a joint in which the first and second members were fastened together. A screw was also used to form a thread at the joint. In test example 2, the strength of the first and second members was higher than in test example 1, but they could be joined under the same conditions as in test example 1, and the screw could be driven with low energy. This is thought to be because the thermal conductivity of the first and second members was 0.2 [kW / m K] in test example 1 and 0.15 [kW / m K] in test example 2, and as a result, the temperature rise during screw driving was promoted in test example 2.

[0056] (A3) Test Example 3 In the test example 3, as shown in FIG. 20, the screw 10 was driven into the first member 21 and the second member 23 overlapping each other in the plate thickness direction, and a joint 27 was obtained in which the first member 21 and the second member 23 were fastened. However, since the screw 10 was driven in a position close to the step having the welded portion Sj, collapse C occurred in the thread 25a formed in the joint 25. In this way, when the screw 10 was driven in the vicinity of the welded portion Sj, the formation of the thread 25a was affected. In other words, the plastic flow occurred in the welded portion Sj, and the joint 25 became uneven, such as a part of the thread 25a being chipped, and a gap was generated between the joint 25 and the screw 10. In this case, the adhesion between the joint 25 and the screw 10 is reduced, and the joint quality is reduced.

[0057] (A4) Test Example 4 In Test Example 4, the first member and the second member with a thickness of 5.5 mm were overlapped with each other and the screw was driven into them. However, the screw could only be inserted halfway into the second member, and it was difficult to drive it in any further. In Test Example 4, the thickness of the second member was thicker than 5.0 mm, and it is believed that the frictional heat between the screw and the joint was diffused (dissipated) to the surroundings, and sufficient temperature rise was not achieved.

[0058] (A5) Test Example 5 In Test Example 5, it was possible to drive a screw into the first and second members that were overlapped with each other. However, in the second member made of a die-cast material, although a screw thread could be formed, it was difficult to form a protruding shape that protruded from the joint part toward the screw driving direction. In this case, the area where the screw thread is formed is narrowed, making it difficult to obtain sufficient joint quality.

[0059] As described above, in test examples 1 and 2, (1) the screws were able to be driven in, and (2) there was no collapse of the threads, resulting in high-quality joints. However, in test examples 3 to 5, there were problems with (1) and (2) above, resulting in lower joint quality than in test examples 1 and 2.

[0060] [Second test] The first member 21 and the second member 23 having welded portions Sj along the plate surface direction and the extrusion direction were joined by FSW at the butt joint where the end faces along the extrusion direction were butted against each other, and the joining condition was evaluated.

[0061] <Test conditions> (B1) Test Example 6 The first member and the second member were joined by friction stir welding on one plate surface of the first member and the second member and on the other plate surface on the opposite side thereof, within an area not exceeding the thickness direction of the welded portion formed at the center position in the thickness direction. (B2) Test Example 7 Friction stir welding was performed on one plate surface of the first member and the second member in an area extending in the thickness direction beyond a welded portion formed at the center position in the plate thickness direction, to join the first member and the second member.

[0062] <Evaluation Results> (B1) Test Example 6 21, the friction stir welded portion B was formed on both the front and back plate surfaces within an area not exceeding the welded portion Sj, and no deformation of the welded portion Sj occurred. In this way, the effect of friction stir welding on the welded portion Sj was suppressed, and the first member 21 and the second member 23 were satisfactorily joined without causing defects such as voids.

[0063] (B2) Test Example 7 As shown in Fig. 22, the friction stir welded portion B formed from the back plate surface over the welded portion Sj deformed the welded portion Sj and generated a void V in a part of the welded portion Sj. In this way, the friction stir welded portion B affected the welded portion Sj and generated a defect (void V) near the welded portion Sj.

[0064] As such, the present invention is not limited to the above-described embodiments, and the present invention also contemplates mutual combinations of the various components of the embodiments, as well as modifications and applications by those skilled in the art based on the descriptions in the specification and well-known technologies, and these are included in the scope of protection sought.

[0065] As described above, the present specification discloses the following: (1) A method for joining aluminum materials, which joins a first member formed by extruding an aluminum material made of aluminum or an aluminum alloy to a second member made of the aluminum material, the first member has a welded portion in a part thereof, the welded portion being a joint surface formed along a thickness direction and an extrusion direction, the joint surface being branched by plastic flow during extrusion molding and then reunited to be diffusion-joined; The second member is overlapped at least on a non-welded portion of the first member where the welded portion is not formed to form an overlapping portion; a rod-shaped fastening member for joining is pressed against the overlapping portion and rotated, and the fastening member for joining is penetrated into the overlapping portion while causing plastic flow of the overlapping portion by generated frictional heat, thereby joining the first member and the second member; A method for joining aluminum materials. According to this method of joining aluminum materials, the first and second members are joined by driving a fastening member into the overlapping portion where the second member is overlapped on at least the non-welded portion of the first member, while avoiding the welded portion, so that the first and second members can be joined with high strength without affecting the welded portion, which is the discontinuous portion of the first member.

[0066] (2) The joining fastening member includes a shaft portion and a head portion connected to a base end of the shaft portion, the shaft portion having a threaded portion having a screw thread on an outer circumferential surface thereof and a pointed shaft tip portion provided on a tip side of the threaded portion, The method for joining aluminum materials described in (1), further comprising rotating the fastening member around the axis of the shaft portion while pushing it into the overlapping portion from the tip of the shaft, passing the shaft portion through the overlapping portion and engaging the threads of the screw portion with the overlapping portion. According to this method for joining aluminum materials, the threads of the threaded portion of the joining fastening member can be formed in the first and second members without affecting the welded portion, which is the discontinuous portion of the first member. This allows the joining fastening member to be securely engaged with the first and second members, thereby firmly joining the first and second members.

[0067] (3) The method for joining aluminum materials according to (1) or (2), wherein the thickness of the overlapping portion of the second member is 1.0 mm or more and 5.0 mm or less. According to this method for joining aluminum materials, the shank of the screw can be reliably inserted into the second member while maintaining the rigidity of the joint between the first member and the second member.

[0068] (4) A method for joining aluminum materials, which joins a first member formed by extruding an aluminum material made of aluminum or an aluminum alloy to a second member made of the aluminum material, the first member has a welded portion in a part thereof, the welded portion being a joint surface formed along a thickness direction and an extrusion direction, the joint surface being branched by plastic flow during extrusion molding and then reunited to be diffusion-joined; The second member is overlapped at least on a non-welded portion of the first member where the welded portion is not formed to form an overlapping portion; While pressing a tip of a friction stir welding tool against the overlapping portion and rotating it, the tip is moved along the interface between the first member and the second member of the overlapping portion to friction stir weld the first member and the second member of the overlapping portion. A method for joining aluminum materials. According to this method for joining aluminum materials, the first member and the second member are friction stir welded together while avoiding the welded portion, so that the first member and the second member can be joined with high strength without affecting the welded portion, which becomes a discontinuous portion.

[0069] (5) A method for joining aluminum materials, which joins a first member formed by extruding an aluminum material made of aluminum or an aluminum alloy to a second member made of the aluminum material, The first member has a welded portion in a part thereof, in which a joining surface that is branched by plastic flow during extrusion molding and then reunites and diffusion-joined is formed in a width direction perpendicular to a thickness direction and an extrusion direction, and along the extrusion direction; forming an overlapping portion by butting the second member against an end surface of the first member along the extrusion direction; A tip of a friction stir welding tool is pressed against the overlapping portion and rotated while moving along the interface between the first member and the second member of the overlapping portion to friction stir weld the overlapping portion in the thickness direction within a range not exceeding the welded portion, from one plate surface side and the other plate surface side of the first member, respectively. A method for joining aluminum materials. According to this method of joining aluminum materials, a second member is butted against the end face of a first member having a welded portion to form an overlapping portion, and this overlapping portion is friction stir welded to an extent that does not exceed the welded portion in the thickness direction. Therefore, the first member and the second member can be joined with high strength without affecting the welded portion, which becomes a discontinuous portion.

[0070] (6) The method for joining aluminum materials described in any one of (1) to (5), wherein the first member is a hollow material formed by porthole extrusion of the aluminum material. According to this method for joining aluminum materials, a first member made of a hollow material obtained by porthole extrusion of aluminum material can be firmly joined to a second member by plastic flow caused by thermal friction.

[0071] (7) A step of determining a joining position between the first member and the second member and a position of the welded portion, The method for joining aluminum materials described in any one of (1) to (6), wherein the process includes at least one of a step of positioning the joining position at a position away from the welded portion and a step of forming the welded portion at a position away from the joining position. According to this method for joining aluminum materials, by performing at least one of the steps of positioning the joining position away from the welded portion and forming the welded portion at a position away from the joining position, it is possible to join the first member and the second member with high strength without affecting the welded portion, which is a discontinuous portion of the first member.

[0072] (8) The method for joining aluminum materials according to any one of (1) to (7), wherein the first member has a marking portion indicating the position of the welded portion. According to this method for joining aluminum materials, the position of the welding portion in the first member can be easily grasped by checking the marked portion, and thus the first member and the second member can be easily joined at a position away from the marked portion.

[0073] (9) The method for joining aluminum materials described in (8), wherein the marking portion is formed by a shape characteristic portion including any one of a recess, a protrusion, or a step, or a printed layer. According to this method for joining aluminum materials, by checking the marking portion consisting of a shape characteristic portion including either a recess, a protrusion, or a step, the position of the welded portion in the first member can be easily grasped, thereby improving the ease of joining.

[0074] (10) A joined body of aluminum materials, which joins a first member formed by extruding an aluminum material made of aluminum or an aluminum alloy to a second member made of the aluminum material, the first member has a welded portion in a part thereof, the welded portion being a joint surface formed along a thickness direction and an extrusion direction, the joint surface being branched by plastic flow during extrusion molding and then reunited to be diffusion-joined; a rod-shaped fastening member for joining is provided at an overlapping portion between a non-welded portion of the first member where the welded portion is not formed and the second member, penetrating the first member and the second member, and the first member and the second member are joined together; Aluminum material joint. In this joined body of aluminum materials, the joining fastening member penetrates at least the overlapping portion where the second member is overlapped on the non-welded portion of the first member, so that the welded portion, which is the discontinuous portion of the first member, is not affected, and a joined body in which the first member and the second member are joined with high strength can be obtained.

[0075] (11) The joining fastening member includes a shaft portion and a head portion connected to a base end of the shaft portion, the shaft portion having a threaded portion on an outer circumferential surface thereof and a pointed shaft tip portion provided on a tip side of the threaded portion, The aluminum material joint described in (10) above, wherein the shaft portion of the joining fastening member is passed through the overlapping portion, and the threads of the screw portion and the overlapping portion are engaged with each other. In this joined body of aluminum materials, the threads of the threaded portion of the joining fastening member are firmly engaged with the first and second members without affecting the welded portion, which is a discontinuous portion, thereby obtaining a joined body in which the first and second members are joined with high strength.

[0076] (12) The joined body of aluminum materials according to (10) or (11), wherein the thickness of the second member at the portion joined to the first member is 1.0 mm or more and 5.0 mm or less. This aluminum joint allows the shank of the screw to be securely inserted into the second member while maintaining the rigidity of the joint between the first member and the second member.

[0077] (13) A joined body of aluminum materials, in which a first member formed by extruding an aluminum material made of aluminum or an aluminum alloy and a second member made of the aluminum material are joined together, the first member has a welded portion in a part thereof, the welded portion being a joint surface formed along a thickness direction and an extrusion direction, the joint surface being branched by plastic flow during extrusion molding and then reunited to be diffusion-joined; A friction stir welded portion that joins the first member and the second member is formed at an overlapping portion between a non-welded portion of the first member where the welded portion is not formed and the second member, Aluminum material joint. In this joined body of aluminum materials, the friction stir welded portion is formed at the overlapping portion where the second member is overlapped on the non-welded portion of the first member, so that the welded portion, which becomes a discontinuous portion, is not affected, and a joined body in which the first member and the second member are joined with high strength can be obtained.

[0078] (14) A joined body of aluminum materials, in which a first member formed by extruding an aluminum material made of aluminum or an aluminum alloy and a second member made of the aluminum material are joined together, The first member has a welded portion in a part thereof, in which a joining surface that is branched by plastic flow during extrusion molding and then reunites and diffusion-joined is formed in a width direction perpendicular to a thickness direction and an extrusion direction, and along the extrusion direction; At the overlapping portion where the second member is butted against the end surface along the extrusion direction of the first member, friction stir welded portions that join the first member and the second member are formed from one plate surface side and the other plate surface side of the first member in the thickness direction without exceeding the welded portion, Aluminum material joint. In this joined body of aluminum materials, a friction stir weld is formed at the overlapping portion where the end face of the first member having the welded portion and the second member are butted together, but does not exceed the welded portion in the thickness direction, so that the welded portion, which becomes a discontinuous portion, is not affected. This results in a joined body in which the first member and the second member are joined with high strength.

[0079] (15) The joined aluminum material according to any one of (10) to (14), wherein the first member is a hollow member made of an extrusion molding. According to this joined body of aluminum materials, the first member, which is a hollow extrusion product of aluminum material, is firmly joined to the second member by plastic flow caused by thermal friction to form a joined body.

[0080] (16) The joined aluminum material body according to any one of (10) to (15), wherein the first member has a marking portion indicating the position of the welded portion. With this joined aluminum material, the position of the welded portion of the first member joined to the second member can be easily ascertained by checking the marked portion.

[0081] (17) The aluminum material joint according to (16), wherein the marking portion is formed by a shape characteristic portion including any one of a recess, a protrusion, or a step, or a printed layer. With this aluminum material joint, the position of the welded portion in the first member joined to the second member can be easily grasped by checking the shape characteristic portion, which includes any of a recess, a protrusion, or a step, or the marking portion formed by the printing layer. [Explanation of symbols]

[0082] 10 Screw (fastening member for joining) 13 Shaft 15 Head 17 Shaft tip 19 Threaded section 19a thread 21 First member 23 Second member 27 Zygote 30 Friction stir welding tools 110 Extrusion panel (hollow profile) B Friction stir welded part M marking part O Overlapped part Sj weld part X Extrusion direction

Claims

1. A method for joining aluminum materials, comprising joining a first member formed by extruding an aluminum material made of aluminum or an aluminum alloy to a second member made of the aluminum material, the first member has a welded portion in a part thereof, the welded portion being a joint surface formed along a thickness direction and an extrusion direction, the joint surface being branched by plastic flow during extrusion molding and then reunited to be diffusion-joined; The second member is overlapped at least on a non-welded portion of the first member where the welded portion is not formed to form an overlapping portion; a rod-shaped fastening member for joining is pressed against the overlapping portion and rotated, and the fastening member for joining is penetrated into the overlapping portion while causing plastic flow of the overlapping portion by generated frictional heat, thereby joining the first member and the second member; A method for joining aluminum materials.

2. The joining fastening member includes a shaft portion and a head portion connected to a base end of the shaft portion, the shaft portion having a threaded portion on an outer circumferential surface thereof and a pointed shaft tip portion provided on a tip side of the threaded portion, the fastening member for joining is pushed into the overlapping portion from the tip end of the shaft while rotating about the axis of the shaft portion, so that the shaft portion penetrates the overlapping portion and the threads of the screw portion are engaged with the overlapping portion; The method for joining aluminum materials according to claim 1.

3. The thickness of the overlapping portion of the second member is 1.0 mm or more and 5.0 mm or less. The method for joining aluminum materials according to claim 1 or 2.

4. A method for joining aluminum materials, comprising joining a first member formed by extruding an aluminum material made of aluminum or an aluminum alloy to a second member made of the aluminum material, the first member has a welded portion in a part thereof, the welded portion being a joint surface formed along a thickness direction and an extrusion direction, the joint surface being branched by plastic flow during extrusion molding and then reunited to be diffusion-joined; The second member is overlapped at least on a non-welded portion of the first member where the welded portion is not formed to form an overlapping portion; While pressing a tip of a friction stir welding tool against the overlapping portion and rotating it, the tip is moved along the interface between the first member and the second member of the overlapping portion to friction stir weld the first member and the second member of the overlapping portion. A method for joining aluminum materials.

5. A method for joining aluminum materials, comprising joining a first member formed by extruding an aluminum material made of aluminum or an aluminum alloy to a second member made of the aluminum material, The first member has a welded portion in a part thereof, in which a joining surface that is branched by plastic flow during extrusion molding and then reunites and diffusion-joined is formed in a width direction perpendicular to a thickness direction and an extrusion direction, and along the extrusion direction; forming an overlapping portion by butting the second member against an end surface of the first member along the extrusion direction; A tip of a friction stir welding tool is pressed against the overlapping portion and rotated while moving along the interface between the first member and the second member of the overlapping portion to friction stir weld the overlapping portion in the thickness direction within a range not exceeding the welded portion, from one plate surface side and the other plate surface side of the first member, respectively. A method for joining aluminum materials.

6. The first member is a hollow member formed by porthole extrusion of the aluminum material. The method for joining aluminum materials according to any one of claims 1, 4 and 5.

7. determining a joining position between the first member and the second member and a position of the welded portion; The process includes at least one of a step of arranging the joining position at a position away from the welded portion and a step of forming the welded portion at a position away from the joining position. The method for joining aluminum materials according to any one of claims 1, 4 and 5.

8. The first member has a marking portion indicating the position of the welded portion. The method for joining aluminum materials according to any one of claims 1, 4 and 5.

9. The marking portion is formed by a shape characteristic portion including any one of a recess, a protrusion, or a step, or a printing layer. The method for joining aluminum materials according to claim 8.

10. A joint body of an aluminum material, which is a first member formed by extruding an aluminum material made of aluminum or an aluminum alloy, and a second member formed of the aluminum material, the first member has a welded portion in a part thereof, the welded portion being a joint surface formed along a thickness direction and an extrusion direction, the joint surface being branched by plastic flow during extrusion molding and then reunited to be diffusion-joined; a rod-shaped fastening member for joining is provided at an overlapping portion between a non-welded portion of the first member where the welded portion is not formed and the second member, penetrating the first member and the second member, and the first member and the second member are joined together; Aluminum material joint.

11. The joining fastening member includes a shaft portion and a head portion connected to a base end of the shaft portion, the shaft portion having a threaded portion on an outer circumferential surface thereof and a pointed shaft tip portion provided on a tip side of the threaded portion, The shaft portion of the joining fastening member is passed through the overlapping portion, and the threads of the screw portion and the overlapping portion are engaged with each other. A joined body of aluminum materials according to claim 10.

12. The thickness of the portion of the second member joined to the first member is 1.0 mm or more and 5.0 mm or less. A joined body of aluminum materials according to claim 10 or 11.

13. A joint of aluminum materials in which a first member formed by extruding an aluminum material made of aluminum or an aluminum alloy and a second member made of the aluminum material are joined, the first member has a welded portion in a part thereof, the welded portion being a joint surface formed along a thickness direction and an extrusion direction, the joint surface being branched by plastic flow during extrusion molding and then reunited to be diffusion-joined; A friction stir welded portion that joins the first member and the second member is formed at an overlapping portion between a non-welded portion of the first member where the welded portion is not formed and the second member, Aluminum material joint.

14. A joint of aluminum materials in which a first member formed by extruding an aluminum material made of aluminum or an aluminum alloy and a second member made of the aluminum material are joined, The first member has a welded portion in a part thereof, in which a joining surface that is branched by plastic flow during extrusion molding and then reunites and diffusion-joined is formed in a width direction perpendicular to a thickness direction and an extrusion direction, and along the extrusion direction; At the overlapping portion where the second member is butted against the end surface along the extrusion direction of the first member, friction stir welded portions that join the first member and the second member are formed from one plate surface side and the other plate surface side of the first member in the thickness direction without exceeding the welded portion, Aluminum material joint.

15. The first member is a hollow member made of an extrusion molded product. A joined body of aluminum materials according to any one of claims 10, 13 and 14.

16. The first member has a marking portion indicating the position of the welded portion. A joined body of aluminum materials according to any one of claims 10, 13 and 14.

17. The marking portion is formed by a shape characteristic portion including any one of a recess, a protrusion, or a step, or a printing layer. A joined body of aluminum materials according to claim 16.

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