JP2009090297A - Joining method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a joining method for improving gas-tightness and water-tightness of a joined metallic member formed by joining a pair of metallic members with each other, and enhancing the joining force of the metallic members. <P>SOLUTION: The joining method comprises: a butting step of butting a pair of metallic members; a first permanent joining step of performing friction stir welding from a surface A along the butted part J1 of a joined metallic member 1; a second permanent joining step of performing the friction stir welding from a back side B along the butted part 31; a recessed groove bottom surface permanent joining step of performing the friction stir welding along the butted part J1 from the bottom surface of the recessed groove formed along the joined part J1 on the side surface of the joined metallic member 1; a joint member arrangement step of arranging a joint member U for covering a plasticized area formed in the first and second permanent joining steps in the recessed groove; and a joint member permanent joining step of performing the friction stir welding of butted parts of a pair of opposing side walls of the recessed groove and both side surfaces of the joint member U. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a method for joining metal members using friction stirring.

  Friction stir welding (FSW = Friction Stir Welding) is known as a method for joining metal members. Friction stir welding is a process of rotating a rotating tool along the abutting portion between metal members, and plastically flowing the metal at the abutting portion by frictional heat between the rotating tool and the metal member, so that the metal members are solid-phased. It is what is joined. In general, the rotating tool is formed by protruding a stirring pin (probe) on the lower end surface of a cylindrical shoulder portion.

15 and 16 are perspective views showing a conventional joining method in which friction stir welding is performed on a pair of metal members. As shown in FIG. 15, when the thickness of the metal members 101, 101 to be joined is larger than the length of the stirring pin of the rotating tool (not shown), after performing the friction stir welding from the surface 102 side of the metal member 101. In some cases, friction stir welding is also performed from the back surface 103 side.
That is, the conventional joining method 100 performs friction stir welding from both sides of the front surface 102 and the back surface 103 along the abutting portion 104 (two-dot chain line) of the metal members 101, 101, and is a plasticized region formed by friction stir welding. It joins so that the center part of the thickness direction of 105,106 may contact. Thereby, in the butt | matching part 104, it can join without a clearance gap.

Japanese Patent Laying-Open No. 2005-131666 (see FIG. 7)

  However, as shown in FIG. 16, when the thickness of the metal members 111, 111 to be joined is large, even if friction stir welding is performed from the front surface 102 and the back surface 103, the center portion of the abutting portion 104 (two-dot chain line) is not yet present. There is a possibility that a plasticized region will occur. That is, when the thickness of the metal member 111 is very large with respect to the length of the stirring pin of the rotating tool (not shown), even if friction stirring is performed from the front surface 102 and the back surface 103 of the metal member 111, the plasticized region 105 is obtained. , 106 cannot be brought into contact with the central portion in the thickness direction, and a gap (unplasticized region 119) is generated in the central portion of the abutting portion 104. Thus, when the unplasticized area | region 119 which continues from the one side surface 107 to the other side surface 108 arises, there existed a problem that the watertightness and airtightness between the side surface 107 and the side surface 108 fell.

  Here, if the length of the stirring pin of the rotary tool is increased according to the thickness of the metal member 111, it is possible to join the metal members 111 without gaps by performing friction stir welding from the front surface 102 and the back surface 103. is there. However, since the rotating tool moves while the stirring pin is buried in the metal member 111 and rotates at a high speed, if the length of the stirring pin is increased, the load acting on the driving means of the friction stirrer and the stirring pin increases. However, there is a problem that the life of the apparatus is shortened.

  Further, as shown in FIGS. 15 and 16, in the plasticized regions 105 and 106, a tunnel-like cavity defect 109 (hereinafter referred to as a tunnel-like cavity defect) that continues from one side surface 107 to the other side surface 108 may occur. There is sex. Such a tunnel-like cavity defect 109 contributes to a decrease in watertightness and airtightness between the side surface 107 and the side surface 108 of the metal members 111, 111. In addition, there is a problem that the bonding force between the metal members 111 is weak only by frictional stirring at the abutting portion 104 exposed on the front surface 102 and the back surface 103.

  From such a viewpoint, the present invention improves the airtightness and watertightness of the metal members to be joined formed by joining a pair of metal members, and can increase the joining force between the metal members. It is an object to provide a method.

  A joining method according to the present invention that solves such a problem is a joining method in which a rotating tool is moved to perform friction stir, a joining step of joining a pair of metal members, and a joining portion between the metal members In the first main joining step of performing friction stir from the surface of the metal member, the second main joining step of performing friction stir from the back surface of the metal member to the abutting portion, and the side surface of the metal member, A concave groove bottom surface main joining step in which friction stirring is performed along the abutting portion from a bottom surface of the concave groove formed along the abutting portion, and the first main joining step and the second main joining step in the concave groove. A joint member disposing step of disposing a joint member that covers the plasticized region formed by the step, a butting portion between one metal member and the joint member, and a butting portion between the other metal member and the joint member Fitting stirrer with friction stir Characterized in that it comprises a case step.

  In such a joining method, a joint member that covers the plasticized region formed in the first main joining step and the second main joining step is disposed in a concave groove formed on a side surface of the metal member, and the metal member and the joint are arranged. Since the abutting portions of the members are frictionally stirred, the water tightness and air tightness between the side surfaces of the metal members can be improved. In addition, friction stir is performed on the abutting portion exposed on the bottom surface of the concave groove formed on the side surface of the metal member, and friction stir is also performed on the abutting portion between the metal member and the joint member. You can increase your power.

  Further, in the joint member main joining step, it is preferable to perform friction stirring on the abutting portion between the bottom surface of the concave groove and the lower surface of the joint member.

  In this joining method, since the unplasticized region formed on the bottom surface of the concave groove and the lower surface of the joint member can be frictionally stirred, the water tightness and air tightness between the metal members can be further improved.

Moreover, it is preferable to divide the tunnel-shaped cavity defect formed in the said ditch | groove bottom face main joining process by the friction stirring performed at the said joint member main joining process.
In the plasticized region formed by the first main joining step and the second main joining step, a first repairing step of sealing a tunnel-like cavity defect exposed on the bottom surface of the concave groove with a weld metal is included. Is preferred.

  In such a joining method, since the tunnel-like cavity defect formed by friction stirring can be divided or sealed, the watertightness and confidentiality between metal members can be further enhanced.

  Moreover, it is preferable that the width | variety of the said ditch | groove is larger than the width | variety of the plasticization area | region formed by said 1st main joining process and 2nd main joining process.

  In such a joining method, since the width of the groove is formed larger than the width of the plasticized region formed by the first main joining step and the second main joining step, the first main joining step and the second main joining step are performed. Friction stirring can be performed using the rotary tool used in the process. Thereby, it is possible to save the trouble of changing the rotating tool.

  Moreover, it is preferable that a pilot hole is formed in advance at a position where the rotating tool is to be inserted. According to such a joining process, it is possible to reduce press-fit resistance when the rotary tool is pushed in. Thereby, while improving the precision of friction stir welding, a joining operation can be performed rapidly.

  According to the joining method concerning the present invention, while improving the airtightness and watertightness of the to-be-joined metal member formed by joining a pair of metal members, the joining force of a butt part can be raised.

[First embodiment]
As shown in FIG. 1, the joining method according to the first embodiment of the present invention is a butt exposed on the front surface A and the back surface B of the joined metal member 1 formed by abutting the first metal member 1 a and the second metal member 1 b. Friction stirring is performed along the part J1, and the joint member U is disposed in the concave grooves formed on both side surfaces of the bonded metal member 1, so that the joint member U, the first metal member 1a, and the second metal member 1b Friction stirring is performed on the butt portion.
First, the metal member 1 to be bonded of the bonding method according to the present embodiment will be described in detail, and the first tab material 2 and the second tab material 3 used when bonding the metal member 1 to be bonded will be described in detail. . Further, the vertical and horizontal directions in the description follow the arrows in FIG.

As shown in FIGS. 2A and 2B, the metal member 1 to be joined includes a first metal member 1a and a second metal member 1b that are rectangular in cross-section, and each end face is abutted. Thus, the abutting portion J1 is formed. In the present embodiment, the first metal member 1a and the second metal member 1b are metal materials having the same composition, for example, friction such as aluminum, aluminum alloy, copper, copper alloy, titanium, titanium alloy, magnesium, and magnesium alloy. It consists of a stirrable metal material. Although there is no restriction | limiting in particular in the shape and dimension of the 1st metal member 1a and the 2nd metal member 1b, It is desirable to make the thickness dimension in the abutting part J1 the same at least.
In addition, as shown in FIG. 1, let the surface of the to-be-joined metal member 1 be the surface A, the back surface is the back surface B, one side surface is the 1st side surface C, and the other side surface is the 2nd side surface D.

  As shown in FIGS. 2A and 2B, the first tab member 2 and the second tab member 3 are arranged so as to sandwich the butted portion J1 of the metal member 1 to be joined, The seam (boundary line) between the first metal member 1a and the second metal member 1b, which is attached to the bonded metal member 1 and appears on the first side surface C and the second side surface D, is obscured. Although there is no restriction | limiting in particular in the material of the 1st tab material 2 and the 2nd tab material 3, In this embodiment, it forms with the metal material of the same composition as the to-be-joined metal member 1. FIG. Moreover, although there is no restriction | limiting in particular in the shape and dimension of the 1st tab material 2 and the 2nd tab material 3, In this embodiment, the surface and back surface of the 1st tab material 2 and the 2nd tab material 3 are to-be-joined metal. The surface 1 and the back surface B of the member 1 are formed flush with each other.

  Next, referring to FIG. 3A to FIG. 3C, a rotary tool F (hereinafter referred to as “small rotating tool F”) used in a temporary joining step described later, and a joint member described later. Rotating tool G used in the main joining process (hereinafter referred to as “medium-sized joining rotating tool G”), and rotating tool H (used in the first main joining process, the second main joining process, and the groove bottom main joining process described later) Hereinafter, the “large-sized joining rotary tool H” will be described in detail.

  The small joining rotary tool F shown in FIG. 3 (a) is made of a metal material harder than the metal member 1 to be joined, such as tool steel, and has a cylindrical shoulder portion F1 and a lower end face F11 of the shoulder portion F1. And an agitating pin (probe) F2 provided in a protruding manner. The size and shape of the small joining rotary tool F may be set in accordance with the material and thickness of the metal member 1 to be joined, but at least the medium joining rotary tool G (used in the joint member main joining step described later) (See (b) of FIG. 3). In this way, since it is possible to perform temporary joining with a load smaller than the joint member main joining step, it is possible to reduce the load applied to the friction stirrer at the time of temporary joining, and further, the rotation for small joining Since the moving speed (feeding speed) of the tool F can be made faster than the moving speed of the medium-sized joining rotary tool G, the working time and cost required for temporary joining can be reduced.

The lower end surface F11 of the shoulder portion F1 is a portion that plays a role of pressing the plastic fluidized metal and preventing scattering to the surroundings, and is formed in a concave shape in this embodiment. Not particularly limited to the size of the outer diameter X ₁ of the shoulder portion F1, but in the present embodiment, is smaller than the outer diameter Y ₁ of the shoulder portion G1 of the rotary tool G for medium-sized junction.

The stirring pin F2 hangs down from the center of the lower end surface F11 of the shoulder portion F1, and is formed into a tapered truncated cone shape in this embodiment. In addition, a stirring blade engraved in a spiral shape is formed on the peripheral surface of the stirring pin F2. There is no particular limitation on the size of the outer diameter of the stirring pin F2, in the present embodiment, the maximum outer diameter of the stirring pin G2 of the maximum outer diameter (upper diameter) X ₂ is rotated for medium-sized welding tool G (upper end diameter) Y ₂ smaller than, and the minimum outer diameter (bottom diameter) _{X 3} is smaller than the minimum outer diameter (bottom diameter) _{Y 3} of the stirring pin G2. The length L ₁ of the stirring pin F2 is smaller than the length of the stirring pin G2 for medium-sized joint rotation tool G L _{2 (see} (b) of FIG. 3).

  The middle-sized joining rotary tool G shown in FIG. 3B is made of a metal material harder than the metal member 1 to be joined, such as tool steel, and has a shoulder portion G1 having a columnar shape, and a lower end face G11 of the shoulder portion G1. And an agitating pin (probe) G2 provided in a protruding manner. That is, the medium-sized joining rotary tool G has a substantially similar shape to the small joining rotary tool F, and is larger than the small joining rotary tool F.

  A rotating tool H for large-scale joining shown in FIG. 3C is made of a metal material harder than the metal member 1 to be joined, such as tool steel, and has a cylindrical shoulder portion H1 and a lower end face H11 of the shoulder portion H1. And an agitating pin (probe) H2 provided in a protruding manner. That is, the large-sized joining rotary tool H has a substantially similar shape to the medium-sized joining rotary tool G, and is larger than the middle-sized joining rotary tool G.

  Hereinafter, the joining method according to the present embodiment will be described in detail. The joining method according to the present embodiment includes (1) a butting step, (2) a first main joining step, (3) a second main joining step, (4) a groove forming step, and (5) a groove bottom bottom joining step. (6) First joint member arranging step, (7) First joint member temporary joining step, (8) First joint member main joining step, (9) Second joint member arranging step, (10) Second joint member A temporary joining step and (11) a second joint member main joining step.

(1) Butting process As shown in (a) and (b) of FIG. 2, the butting process includes a butting process in which end surfaces of the first metal member 1a and the second metal member 1b are butted, and a metal member to be joined. The tab material arrangement | positioning process which arrange | positions the 1st tab material 2 and the 2nd tab material 3 on both sides of 1 is included.

  In the abutting step, as shown in FIGS. 2A and 2B, the end surface 11a of the first metal member 1a and the end surface 11b of the second metal member 1b are abutted, and the surface 12a of the first metal member 1a. And the surface 12b of the second metal member 1b are flush with each other, and the back surface 13a of the first metal member 1a and the back surface 13b of the second metal member 1b are flush with each other. Further, the side surface 14a of the first metal member 1a and the side surface 14b of the second metal member 1b are flush with each other, and the side surface 15a of the first metal member 1a and the side surface 15b of the second metal member 1b are flush with each other. To do.

  In the tab material arranging step, the first tab material 2 and the second tab material 3 are arranged along the abutting portion J1 of the bonded metal member 1. In the present embodiment, the contact surface 21 of the first tab member 2 is disposed so as to contact the second side surface D of the bonded metal member 1. Further, the contact surface 31 of the second tab member 3 is disposed so as to contact the first side surface C of the bonded metal member 1. The 1st tab material 2 is temporarily joined by welding by the to-be-joined metal member 1 and entering corner part 2a, 2b. The 2nd tab material 3 is temporarily joined by welding by the to-be-joined metal member 1 and entering corner part 3a, 3b. Thus, by temporarily joining the tab material and the metal member 1 to be joined, it is possible to prevent the opening during the first main joining step and the second main joining step described later.

(2) First Main Joining Process In the first main joining process, as shown in FIG. 4, friction stirring is performed using a large joining rotary tool H along the abutting portion J1 exposed on the surface A of the metal member 1 to be joined. I do. In the first main joining step, in the present embodiment, the start position S _M1 is set for the first tab member 2, the end position E _M1 is set for the second tab member 3, and the large-sized joining rotary tool H is set to the right. Rotate and stir frictionally as a single stroke.

In the first main joining step, as shown in FIG. 4, the large-position joining rotary tool H is pressed against the start position S _M1 in a rotated state, and the large-position joining rotary tool H is not detached, and the end position E _M1 is removed. Move to a relative position. That is, After pressing the rotary tool H for large joining the start position S _M1, is moved toward the starting point s1 of the single joining step, friction stir along the butting portion J1 without disengaging the rotary tool H for large junction I do. When the end point s2 of the first main joining process is reached, the large joining rotary tool H is moved to the end position E _M1 set for the second tab member 3 as it is, and the large joining rotary tool H is moved to the second tab member 3. To leave. According to the first main joining step, as shown in FIG. 4, the plasticized region W1 is formed along the abutting portion J1. The width of the plasticized region W1 is hereinafter referred to as a width Wa.

In the first main joining step, a pilot hole P1 may be provided in advance on the surface 22 of the first tab member 2 as shown in FIG. Pilot bore P1 according to this embodiment is notched into a cylindrical shape and is formed such that the depth of the prepared hole P1 is smaller than the length L ₃ of the stirring pin H2. By providing the pilot hole P <b> 1, it is possible to reduce press-fit resistance when the large-sized joining rotary tool H is pushed into the first tab member 2. Thereby, while improving the precision of friction stirring, joining work can be performed rapidly. Shape of the prepared hole P1, the size is not limited, the size of the opening of P1 is smaller than the maximum outer diameter Z ₂ of the stirring pin H2, it is greater than the minimum outer diameter Z ₃ preferable.

Moreover, you may perform a temporary joining process with respect to the abutting part J1 prior to a 1st main joining process. That is, in the temporary joining step, as shown in FIG. 4, for example, using the small joining rotary tool F, the abutting portion J2 between the first tab member 2 and the metal member 1 to be joined, the abutting portion J1, and the second tab member. Friction stirring is performed on the abutting portion J3 between the metal member 3 and the metal member 1 to be joined. By performing the temporary joining step before the first main joining step, the opening between the tab material and the metal member 1 to be joined can be prevented.
Moreover, in this joining process, when the to-be-joined metal member 1 becomes high heat | fever by friction, work may be performed, supplying water to the butt | matching part J1. In such a case, if a temporary joining step is performed, water does not enter the gap of the abutting portion J1, so that a high-quality product can be supplied.

In the present embodiment, although the start position S _M1 of the welding process is provided on the first tab member 2 may be provided on the second tab member 3. Moreover, in this embodiment, although the main joining process was performed using the tab material, the tab material is not necessarily provided.

(3) Second Main Joining Step In the second main joining step, as shown in FIG. 5, friction stirring is performed using the large joining rotary tool H along the abutting portion J1 exposed on the back surface B of the metal member 1 to be joined. I do. When the first main joining process is completed, the metal member 1 to be joined is removed from a friction stirrer (not shown), and is rotated halfway around the front and rear axes (see FIG. 1) of the metal member 1 to be joined, with the back surface B facing upward. Install again in the friction stirrer.
Then, the friction stir in the manner of one stroke from a start position S _M2 set in the first tab member 2, to the end position E _M2 set in the second tab member 3. Since the second main joining step is substantially the same as the first main joining step, detailed description thereof is omitted. By performing the second main joining step, the plasticized region W2 is formed along the abutting portion J1 on the back surface B of the metal member 1 to be joined.

When the second main joining process is completed, the first tab member 2 and the second tab member 3 are cut out from the metal member 1 to be joined. Moreover, it is preferable to cut the surfaces of the plasticized region W1 and the plasticized region W2 smoothly as the tab material is removed. Thereby, in the tab material arrangement | positioning process mentioned later, the to-be-joined metal member 1 and the tab material can be made to contact suitably.
In addition, before performing a 2nd main joining process, you may perform the temporary joining process of joining the to-be-joined metal member 1 and a tab material temporarily using the rotation tool F for small joining. Moreover, you may form a pilot hole previously in the surface of a tab material.

(4) Concave Groove Forming Step The concavity forming step includes a first concave groove forming step of forming the first concave groove K1 on the second side surface D of the metal member 1 to be joined, and the first side surface, as shown in FIG. A second groove forming step for forming the second groove K2 in C, and a first for sealing the cavity defect R exposed to the bottom surface Kd of the first groove K1 and the second groove K2 in the plasticized regions W1 and W2. Repair process.

In the first groove forming step, on the second side D of the metal member 1 to be joined, a first groove having a rectangular cross-sectional view that continues from the back surface B to the surface A along the abutting portion J1 using a known end mill or the like. K1 is formed. The width Ka of the first concave groove K1 is formed larger than the width Wa of the plasticized region W2. In the present embodiment, the depth Kb of the first concave groove K1 is formed to be smaller than the length L ₂ (see FIG. 3B) of the stirring pin G2 of the medium-sized joining rotary tool G. In the first groove K1, the distance from the back surface B to the front surface A is a length Kc.

  In the second concave groove forming step, the second concave groove K2 having a rectangular cross-sectional view continuous from the rear surface B to the front surface A along the abutting portion J1 on the first side surface C of the metal member 1 to be joined using a known end mill or the like. Form. Since the second groove K2 is formed substantially the same as the first groove K1, detailed description thereof is omitted.

  On the bottom surface Kd of the first groove K1 and the bottom surface (not shown) of the second groove K2 formed as described above, an unplasticized region j1 (butting portion) is formed between the plasticized region W1 and the plasticized region W2. J1) is exposed. Further, tunnel-like cavity defects R1 and R2 that communicate from the bottom surface Kd of the first concave groove K1 to the bottom surface (not shown) of the second concave groove K2 are formed in the plasticized region W1 and the plasticized region W2, respectively. .

  In the first repairing step, the tunnel-shaped cavity defects R1 and R2 exposed in the first groove K1 and the second groove K2 are sealed by welding. That is, in the first repair process, for example, MIG welding or the like is performed on the tunnel-like cavity defects R1 and R2, and the cavities of the tunnel-like cavity defects R1 and R2 are sealed with the weld metal. Thereby, the watertightness and confidentiality of the to-be-joined metal member 1 can be improved.

  Note that the unplasticized region j1 may be sealed by welding the unplasticized region j1. Moreover, it is preferable to form smoothly the bottom face Kd of the 1st ditch | groove K1 and the 2nd ditch | groove K2 after a 1st repair process. Thereby, in the joint member arrangement | positioning process mentioned later, a joint member can be suitably arrange | positioned to a ditch | groove.

The concave groove forming step is performed as described above in the present embodiment, but is not limited thereto. For example, an oxide film may be wound on the bonded metal member 1 side at both ends of the plasticized regions W1 and W2 when passing through the abutting portions J2 and J3 (see FIG. 4). In such a case, when forming the concave groove, the concave groove may be formed by adjusting the depth Kb of the concave groove to cut out the oxide film. Further, the shape of the groove is not limited to a rectangular shape in sectional view, and may be set as appropriate according to the shape of the joint member described later.
Moreover, in this embodiment, although the ditch | groove formation process was performed after performing the 1st main joining process and the 2nd main joining process, it is not limited to this. For example, stepped portions are formed in advance on both side surfaces of the first metal member 1a and the second metal member 1b, and a concave groove is formed by abutting the end surfaces of the first metal member 1a and the second metal member 1b. You may be made to do.

(5) Concave groove bottom surface main joining step The indented groove bottom surface main joining step includes a tab material arranging step of disposing a pair of tab materials on the front surface A and the back surface B of the metal member 1 to be joined, and the second side surface D to the abutting portion J1. The first concave groove bottom surface main joining step for friction stirring and the second concave groove bottom surface main joining step for friction stirring the abutting portion J1 from the first side surface C are included.

  First, when the concave groove forming step is finished, the metal member 1 to be joined is installed in a friction stirrer (not shown) with the second side face D facing upward. As shown in FIG. 7, the tab material arranging step is a step of arranging the first tab material 4 and the second tab material 5 on the front surface A and the back surface B of the bonded metal member 1, respectively. The 1st tab material 4 and the 2nd tab material 5 are metal members which consist of a raw material equivalent to the to-be-joined metal member 1, and exhibit a rectangular parallelepiped. The front surface and the back surface of the first tab material 4 and the second tab material 5 are disposed so as to be flush with the bottom surfaces of the first concave groove K1 and the second concave groove K2 (not shown), respectively. The width 5a of the first tab material 4 and the second tab material 5 is formed larger than the width Ka of the first concave groove K1. The 1st tab material 4 and the 2nd tab material 5 and the to-be-joined metal member 1 are temporarily joined by welding. Thereby, when performing a ditch | groove bottom bottom main joining process, the opening of a tab material and the to-be-joined metal member 1 can be prevented.

In the first concave groove bottom surface main joining step, as shown in FIG. 8, the friction stirrer is performed in the manner of a single stroke using a large joining rotary tool H along the abutting portion J1 exposed on the bottom surface Kd of the first concave groove K1. I do. First notches bottom this bonding step, in the present embodiment, to set the start position S _M3 in the first tab member 4, to set the end position E _M3 in the second tab member 5. That is, after the large-sized joining rotary tool H rotated to the start position _SM3 is pressed, the large-joining rotating tool H is relatively moved toward the start point s3 of the first concave groove bottom surface main joining process. Then, the friction stir is performed along the abutting portion J1 without removing the large joining rotary tool H. Then, the end point s4 is passed without detaching the large joining rotary tool H, and the large joining rotary tool H is moved to the end position E _M3 as it is. By the first concave groove bottom surface main joining step, the plasticized region W3 is formed along the abutting portion J1.

As shown in FIG. 6, the width Ka of the first groove K1 is the width Wa of the plasticizing region W1, that is, the outer diameter Z ₁ of the shoulder portion H1 of the large-sized joining rotary tool H ((c of FIG. 3 ) See), the large-sized joining rotary tool H can be used following the second main joining step. Thereby, it is possible to save the trouble of exchanging the rotating tool.

The second concave groove bottom surface main joining step is not specifically illustrated, but friction stir in the manner of one stroke using the large joining rotary tool H along the abutting portion J1 exposed on the bottom surface of the second concave groove K2. I do. Since the second concave groove bottom surface main joining step is substantially the same as the first concave groove bottom surface main joining step, detailed description thereof is omitted. The plasticized region formed in the second concave groove bottom surface main joining step is defined as a plasticized region W4.
In the first concave groove bottom surface main joining step and the second concave groove bottom surface main joining step, a pilot hole may be formed in advance at the friction stirring start position.

(6) 1st joint member arrangement | positioning process A 1st joint member arrangement | positioning process is a 1st auxiliary | assistant tab in the upper part of the 1st tab material 4 and the 2nd tab material 5, as shown to (a) and (b) of FIG. The tab material arrangement | positioning process which arrange | positions the material 6 and the 2nd auxiliary | assistant tab material 7, and the 1st coupling member arrangement | positioning process which arrange | positions the 1st coupling member U1 to the 1st ditch | groove K1 are included. First, the first joint member U1, the first auxiliary tab material 6, and the second auxiliary tab material 7 will be described in detail.

  The first joint member U1 is a metal member having a rectangular parallelepiped shape, and is formed of a metal material having the same composition as the metal member 1 to be joined in the present embodiment. The width Ua of the first joint member U1 is formed substantially equal to the width Ka (see FIG. 6) of the first concave groove K1. Further, the thickness Ub of the first joint member U1 is formed substantially equal to the depth Kb (see FIG. 6) of the first concave groove K1. Further, the length Uc of the first joint member U1 is formed substantially equal to the length Kc (see FIG. 6) of the first concave groove K1. That is, the first joint member U1 is disposed in the first concave groove K1 with almost no gap. The end surfaces d1 and d2 of the first joint member U1 are arranged so as to be flush with the front surface A and the rear surface B of the metal member 1 to be joined.

  The first auxiliary tab member 6 shown in FIG. 9A is a member in which a start position or an end position of a joint member main joining process described later is set. The first auxiliary tab member 6 has a cross-sectional shape equivalent to that of the first tab member 4 and is disposed on the first tab member 4. The thickness of the first auxiliary tab member 6 is formed substantially equal to the thickness Ub of the first joint member U1. That is, the surface of the first auxiliary tab member 6 is formed flush with the surface of the first joint member U1. The first auxiliary tab member 6 has the same composition as the metal member 1 to be joined.

  The second auxiliary tab member 7 shown in FIG. 9A is a member in which a start position or an end position of a joint member main joining process described later is set. The second auxiliary tab member 7 has a cross-sectional shape equivalent to that of the second tab member 5 and is disposed on the upper portion of the second tab member 5. The thickness of the second auxiliary tab member 7 is formed substantially equal to the thickness Ub of the first joint member U1. That is, the surface of the second auxiliary tab member 7 is formed flush with the surface of the first joint member U1. The second auxiliary tab material 7 has the same composition as the bonded metal member 1.

  In the tab material arranging step, the first auxiliary tab material 6 is arranged above the first tab material 4, and the first auxiliary tab material 7 is arranged above the second tab material 5. And the entering corner part of the 1st auxiliary tab material 6 and the 2nd auxiliary tab material 7, and the to-be-joined metal member 1 is temporarily joined by welding. Thereby, the opening by the friction stirring in the joint member main joining process mentioned later can be prevented.

In the first joint member arranging step, the first joint member U1 is arranged in the first concave groove K1.
Here, as shown in FIG. 9B, a butt portion J <b> 6 is formed on the butt surface between the end surface d <b> 1 of the first joint member U <b> 1 and the side surface e <b> 1 of the first auxiliary tab member 6. Further, an abutting portion J7 is formed on the abutting surface between the end surface d2 of the first joint member U1 and the side surface e2 of the second auxiliary tab member 7.
Further, an abutting portion J10 is formed on the abutting surface between the side wall e3 standing vertically from the bottom surface Kd of the first concave groove K1 and the side surface d3 of the first joint member U1. Further, an abutting portion J11 is formed on the abutting surface between the side wall e4 that stands vertically from the bottom surface Kd of the first concave groove K1 and the side surface d4 of the first joint member U1.
In addition, after performing a 1st joint member arrangement | positioning process, you may perform a tab material arrangement | positioning process.

(7) First joint member temporary joining step In the first joint member temporary joining step, friction stir is preliminarily performed from the second side face D side with respect to each abutting portion exposed on the second side face D of the metal member 1 to be joined. I do. In the first joint member temporary joining step, as shown in FIG. 10, using a small joining rotary tool F, friction is applied to the abutting portion J7, the abutting portion J11, the abutting portion J6, and the abutting portion J10 in a one-stroke manner. This is a step of stirring.

The procedure of friction stirring in the first joint member temporary joining step will be described in more detail.
Positions the rotary tool F for small joint just above the second auxiliary tab member 7 starting position S _M4 provided in place of, subsequently, to the starting position S _M4 is lowered while the right rotating the rotary tool F for small joint Press. Then, while rotating the small joining rotary tool F, the small joining rotary tool F is relatively moved toward the temporary joining start point g1 provided at the center of the abutting portion J7 (intermediate between the first intersection point g2 and the fourth intersection point g8).

  When the small tooling rotary tool F is relatively moved and frictional stirring is performed up to the temporary joining start point g1, the first intersection point g2 which is one end of the abutting portion J7 without removing the small joining rotary tool F at the temporary joining start point g1. The friction stir is performed on a part of the abutting portion J7.

  When the small joining rotary tool F is relatively moved to the first intersection g2, the abutting portion between the second auxiliary tab member 7 and the first metal member 1a without being detached from the small joining rotary tool F at the first intersection g2. Relative movement is performed toward the first intermediate point g3 provided at J7a, and friction agitation is performed on the abutting portion J7a.

  When the small joining rotary tool F is relatively moved to the first intermediate point g3, the small joining rotary tool F is rushed into the second auxiliary tab member 7 at the first intermediate point g3 without detachment, and the second auxiliary tab is inserted. The material 7 is relatively moved to the first intersection g2 which is also one end of the abutting portion J11 while performing frictional stirring.

  When the small joining rotary tool F is returned to the first intersection point g2, the small joining rotary tool F is allowed to enter the abutting portion J11 at the first intersecting point g2 without detachment, and friction agitation is performed on the abutting portion J11. The relative movement is made to the second intersection point g4 which is the other end of the abutting portion J11.

  When the small joining rotary tool F is relatively moved to the second intersection point g4, the small joining rotary tool F is allowed to enter the first auxiliary tab member 6 at the second intersection point g4 without detachment, and the first auxiliary tab member 6 is removed. While being frictionally stirred, the first auxiliary tab member 6 and the first metal member 1a are relatively moved to the second intermediate point g5 provided at the abutting portion J6a. That is, the friction stir route from the second intersection point g4 to the second intermediate point g5 is set in the first auxiliary tab member 6.

  When the small joining rotary tool F is relatively moved to the second intermediate point g5, the small joining rotary tool F is not detached at the second intermediate point g5, and is directed toward the second intersection point g4 which is also one end of the abutting portion J6. Relative movement is performed, and friction agitation is performed on the abutting portion J6.

  When the small joining rotary tool F is relatively moved to the second intersection point g4, the small joining rotational tool F is not detached at the second intersection point g4 and is moved toward the third intersection point g6 which is the other end of the abutting portion J6. The friction stir is performed on the abutting portion J6.

  When the small joining rotary tool F is relatively moved to the third intersection point g6, the first auxiliary tab member 6 and the second metal member 1b are directly joined at the third intersection point g6 without detaching the small joining rotary tool F. Relative movement is performed toward the third intermediate point g7 provided in J6b, and friction agitation is performed on the abutting portion J6b.

  When the small joining rotary tool F is relatively moved to the third intermediate point g7, the small joining rotary tool F is moved into the first auxiliary tab member 6 at the third intermediate point g7 without detachment, and the first auxiliary tab is inserted. The material 6 is relatively moved to the third intersection point g6 which is also one end of the abutting portion J10 while performing frictional stirring. That is, the friction stir route for returning the small joining rotary tool F from the third intermediate point g7 to the third intersection point g6 is set in the first auxiliary tab member 6.

  When the small joining rotary tool F is returned to the third intersection point g6, the small joining rotary tool F is allowed to enter the abutting portion J10 as it is without detaching at the third intersection point g6, and friction agitation is performed on the abutting portion J10. The relative movement is made to the fourth intersection point g8 which is the other end of the abutting portion J10.

  When the small joining rotary tool F is relatively moved to the fourth intersection point g8, the small joining rotational tool F is allowed to enter the second auxiliary tab member 7 without being detached at the fourth intersection point g8, and the second auxiliary tab member 7 is moved. The second auxiliary tab member 7 and the second metal member 1b are relatively moved to a fourth intermediate point g9 provided at the abutting portion J7b while performing frictional stirring. That is, the friction stir route from the fourth intersection point g8 to the fourth intermediate point g9 is set in the second auxiliary tab member 7.

  When the small joining rotary tool F is relatively moved to the fourth intermediate point g9, the small joining rotary tool F is not detached at the fourth intermediate point g9, and is directly directed to the fourth intersection point g8 which is also the other end of the abutting portion J7. The friction stir is performed on the abutting portion J7b.

  When the small joining rotary tool F is relatively moved from the fourth intermediate point g9 to the fourth intersecting point g8, the temporary joining provided in the middle of the abutting portion J7 without removing the small joining rotary tool F at the fourth intersecting point g8. Relative movement is made toward the end point g10, and friction stirring is performed on the abutting portion J7.

When the small joining rotary tool F is relatively moved to the temporary joining end point g10, the small joining rotating tool F is directly moved into the second auxiliary tab member 7 without being detached at the temporary joining end point g10. Is moved relative to the friction stirring end position _EM4 .

  Note that when the small joining rotary tool F is rotated to the right, there is a possibility that a fine joining defect may occur on the left side in the traveling direction of the small joining rotary tool F. When the friction stir is performed along the abutting portions J6 and J7 between the auxiliary tab material 7 and the first joint member U1, the first auxiliary tab material 6 and the second auxiliary are on the left side in the traveling direction of the small joining rotary tool F. It is desirable to set the route of friction stirring so that the tab material 7 is located. If it does in this way, since it becomes difficult to generate | occur | produce a joint defect on the 1st joint member U1 side, it becomes possible to obtain a high quality joined body.

  Incidentally, when the small joining rotary tool F is rotated counterclockwise, a fine joining defect may occur on the right side in the traveling direction of the small joining rotary tool F. When the friction stir is performed along the abutting portions J6 and J7 between the auxiliary tab material 7 and the first joint member U1, the first auxiliary tab material 6 and the second auxiliary are on the right side in the traveling direction of the small joining rotary tool F. It is desirable to set the route of friction stirring so that the tab material 7 is located.

  In the present embodiment, the route of the first joint member temporary joining step is set as described above, but is not limited to this route. Further, the first joint member temporary joining step does not necessarily have to be frictionally stirred in the manner of one stroke. Moreover, let the plasticization area | region formed by the 1st joint member temporary joining process be the plasticization area | region W5.

(8) 1st joint member main joining process As shown in FIG. 11, the 1st joint member main joining process is a butt part J11 which carries out friction stirring of the butt | joint part J11 of the 1st joint member U1 and the 1st metal member 1a. Friction stir on the entire surface of the first joint member U1 from above the first joint member U1, a joining step, a joining portion J10 joining step of friction stir the abutting portion J10 of the first joint member 1 and the second metal member 1b And a full-scale main bonding step. That is, in the first joint member main joining step, the middle-sized joining rotary tool G is rotated counterclockwise from the start position S _M5 set on the second auxiliary tab member 7 to the end position E _M5 set on the first auxiliary tab member 6. Let the friction stir in the manner of a single stroke.

The abutting portion J11 main joining step is a step of friction stirring from the starting point h1 of the abutting portion J11 to the end point h2 of the abutting portion J11. That is, in this embodiment, by pressing the rotary tool G for medium-sized junction rotated to the starting position S _M5, relatively moving the rotary tool G for medium-sized joint to the beginning h1 of butting portion J11 present bonding process. Then, the middle-sized joining rotary tool G is moved along the abutting portion J11 without detaching the middle-sized joining rotating tool G, and friction stirring is performed, and the first auxiliary is passed through the end point h2 of the abutting portion J11 main joining process. The tab material 6 is rushed. Then, the intermediate tool rotating tool G is moved substantially parallel to the abutting portion J6 from the break point h3 set to the first auxiliary tab member 6 to the break point h4 without detaching the medium tool rotating tool G.

  Next, the joining part J10 main joining process is a process of friction stirring from the starting point h5 of the joining part J10 to the end point h6 of the joining part J10. That is, when the middle-sized joining rotary tool G reaches the start point h5, friction stirring is performed along the abutting portion J10 without removing the middle-sized joining rotary tool G. Then, when the medium-sized joining rotary tool G reaches the end point h6 of the joining portion J10 main joining process set before the joining portion J7, the rotating tool for medium-size joining is parallel to the joining portion J7 toward the joining portion J11. G is moved and the whole surface main joining process is started.

Entire main bonding step is to perform a friction stir zigzag in the width direction of the first coupling member U1 from the end point h6 to E _M5 set in the first auxiliary tab member 6.
Here, of the plasticized region W6 formed in the first joint main joining step, the region related to the butted portion J11 main joining step is referred to as a plasticized region W6a, and the region related to the butted portion J10 main joining step is referred to as W6b. The region formed in the main joining process is designated as W6c.
The position of the end point h6 is preferably set to a position where the outer edge of the plasticized region W6c does not reach the abutting portion J7. That is, the distance from the abutting portion J7 to h6 is formed to be greater than ½ of the outer diameter Y1 (see FIG. 3B) of the shoulder portion G1 of the medium-sized joining rotary tool G. Thereby, the oxide film existing in the abutting portion J7 can be prevented from being caught by friction stirring.

  Then, when the medium-sized joining rotary tool G reaches the break point h7, the medium-sized joining rotary tool G is moved toward the abutting portion J6 substantially in parallel with the abutting portion J11. At this time, the position of the break point h7 is preferably set so that the plasticized region W6a formed in the abutting portion J11 main joining step and the plasticizing region W6c formed in the entire main joining step overlap. Thereby, the first joint member U1 can be frictionally stirred without a gap.

Then, when the medium-sized joining rotary tool G reaches the break point h8, the medium-sized joining rotary tool G is moved toward the abutting portion J10 and substantially parallel to the abutting portion J7. At this time, the distance ma of break points h7 and break point h8 is smaller than the outer diameter of the shoulder portion G1 for medium-sized joint rotation tool G Y _{1 (see} FIG. 3 (b)). Thereby, adjacent plasticization area | region W6c can be overlapped in a whole surface main joining process.

When the break point h9 is reached, the medium-sized joining rotary tool G is moved substantially parallel to the abutting portion J10 toward the abutting portion J6. The position of the break point h9 is preferably set so that the plasticized region W6b formed in the butt joint J10 main joining step and the plasticizing region W6c formed in the entire main joining step overlap. When the break point h10 is reached, the medium-sized joining rotary tool G is moved again toward the abutting portion J11 in parallel with the abutting portion J7. Hereinafter, friction stirring is performed over the entire surface of the first joint member U1 while repeating the same operation. When friction stirring is performed on the entire surface of the first joint member U1, the medium-sized joining rotary tool G is inserted into the first auxiliary tab member 6, and the medium-sized joining rotary tool G is detached from the end position _EM5 .

Thus, according to the 1st joint member main joining process concerning this embodiment, in the surface of the 1st joint member U1, friction stir is carried out efficiently over the whole surface of butt part J11, butt part J10, and first joint member U1. It can be carried out.
Here, FIG. 12 is a sectional view taken along line II-II in FIG. As shown in FIG. 12, tunnel-like cavity defects R3 and R4 are formed in the plasticized region W6a formed in the butt joint J11 main joining process and the plasticized region W6b formed in the butt joint J10 main joining process. Yes. A tunnel-like cavity defect R5 is formed in the plasticized region W4 formed in the second concave groove bottom surface main joining step.

  As shown in FIG. 12, the plasticized region W6c related to the entire surface main joining process overlaps with the plasticized regions W6a and W6b, thereby sealing the tunnel-like cavity defects R3 and R4. Further, since the depth Qa of the plasticized region W6c is set larger than the depth of the tunnel-like cavity defect R5 formed in the plasticized region W4, the tunnel-like cavity defect R5 is sealed. Thereby, the to-be-joined metal member 1 with high airtightness and watertightness can be formed. Further, by performing frictional stirring on the entire surface of the abutting portion J12 between the bottom surface Kd of the first concave groove K1 (see FIG. 6) and the lower surface d6 of the first joint member U1, the watertightness of the metal member 1 to be bonded is further increased. Sexual and airtightness can be further increased.

  In addition, as shown in FIG. 11, there is a possibility that a cavity defect is exposed on the surface A by passing through the abutting portion J6 in the entire surface main joining process. Repair may be performed to hermetically seal. Moreover, what is necessary is just to set so that the 1st coupling member U1 may be arrange | positioned in the advancing direction left side, when rotating the rotation tool G for medium size joining rightward.

  As explained above, in the (6) first joint member arranging step, (7) first joint member temporary joining step, and (8) first joint member main joining step, the second side D side of the metal member 1 to be joined The process in was performed. Next, the same process is performed also on the first side C side of the metal member 1 to be joined.

(9) Second joint member arranging step In the second joint member arranging step, the second joint member U2 is arranged in the second concave groove K2 formed in the first side surface C, although not specifically illustrated. The second concave groove K2 is formed substantially the same as the first concave groove K1. Further, the second joint member U2 is formed substantially the same as the first joint member U1. Since the second joint member arranging step is substantially the same as the first joint member arranging step described above, detailed description is omitted.

(10) Second Joint Member Temporary Joining Process In the second joint member temporary joining process, although not specifically illustrated, the first side face with respect to each butt portion exposed on the first side face C of the metal member 1 to be joined. Preliminarily friction stir from the C side. Since the second joint member temporary joining step is substantially the same as the first joint member temporary joining step described above, detailed description thereof is omitted.

(11) Second joint member main joining step In the second joint member main joining step, although not specifically shown, the abutting portions of the second joint member U2, the first metal member 1a, and the second metal member 1b are rubbed. While stirring, friction stirring is performed over the entire surface of the second joint member U2. Since the second joint member main joining step is substantially the same as the first joint member main joining step described above, detailed description thereof is omitted.
Finally, the tab material temporarily joined to the metal member 1 to be joined is cut out.

According to the joining method according to the first embodiment described above, the first joint member U1 is arranged in the first concave groove K1 formed in the second side face D of the metal member 1 to be joined, and the abutting portions J10, J11. By friction stirring, the tunnel-like cavity defects R1 and R2 formed in the plasticized regions W1 and W2 are covered, so that the water tightness and the air tightness between the side surfaces of the metal member 1 to be joined can be improved.
Moreover, while performing a ditch | groove bottom face main joining process and also performing friction stir also with respect to the abutting parts J10 and J11 of the 1st joint member U1, the 1st metal member 1a, and the 2nd metal member 1b, between metal members Bonding force can be increased.

  Further, as shown in FIG. 12, by subjecting the entire surface of the abutting portion J12 between the bottom surface Kd of the first concave groove K1 (see FIG. 6) and the bottom surface d6 of the first joint member U1, friction stir can be performed. The watertightness and airtightness of the bonded metal member 1 can be improved.

  Further, as shown in FIG. 12, the full-surface main joining step in the first joint member main joining step seals the tunnel-like cavity defect R5 communicating with the plasticized region W4 formed by the second bottom surface main joining step. Thereby, the watertightness and airtightness of the to-be-joined metal member 1 can be improved further.

[Second Embodiment]
FIG. 13 is a plan view showing the first joint member main joining step according to the second embodiment. 14 is a cross-sectional view taken along line III-III in FIG.
As shown in FIGS. 13 and 14, the first joint member main joining step according to the second embodiment is different from the first embodiment in that the agitation direction of friction stirring is different.

In the first joint member main joining step according to the second embodiment, as shown in FIG. 13, the start position _SM7 set for the second auxiliary tab member 7 to the end position E set for the first auxiliary tab member 6. _This is a step of performing frictional stirring in the manner of one stroke writing up to _M7 . That is, the first joint member main joining step according to the second embodiment includes the abutting portion J11 main joining step of friction stirring the abutting portion J11 between the first joint member U1 and the first metal member 1a, and the first joint member U1. And the abutting portion J10 of the second metal member 1b are frictionally agitated, and a full-surface main joining step of agitating the entire surface of the first joint member U1 from above the first joint member U1. And.
In addition, since the butt | joint part J11 main joining process and the butt | joint part J10 this joining process are substantially equivalent to 1st embodiment, description is abbreviate | omitted.

In the full-scale main joining process according to the second embodiment, when the medium-sized joining rotary tool G reaches the end point g6 of the abutting portion J10, the middle-sized joining rotating tool parallel to the abutting portion J7 toward the abutting portion J11. Move G. When the break point f7 is reached, the medium-sized joining rotary tool G is moved in parallel with the abutting portion J10 toward the abutting portion J6. That is, the full-scale main joining process according to the second embodiment is set such that the traveling direction in the longitudinal direction of the medium-sized joining rotary tool G is parallel to the abutting portion J10.
Here, the distance mb between the end point f6 and the break point f7 is formed to be smaller than the outer diameter Y ₁ of the shoulder of the medium-sized joining rotary tool G (see FIG. 3B). Thereby, the plasticization area | region W6b of the butt | joint part J10 main joining process and the plasticization area | region W6c of a whole surface main joining process can be overlapped.

  Further, as shown in FIG. 14, by overlapping the plasticized regions W6a and W6b formed in the abutting portions J11 and J10 and the plasticized region W6c formed in the entire main bonding process, the tunnel-like cavity defect R3, R4 can be sealed. Further, in order to reciprocate the middle-sized joining rotary tool G over the longitudinal direction of the first joint member U1, the entire surface of the abutting portion J12 between the lower surface d6 of the first joint member U1 and the bottom surface Kd of the first groove K1 is friction-stirred. be able to. Furthermore, since the depth Qa of the plasticized region W6c is set larger than the depth of the tunnel-like cavity defect R5 formed in the plasticized region W4, the tunnel-like cavity defect R5 can be sealed.

  Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and can be appropriately changed without departing from the spirit of the present invention. For example, in the embodiment, concave grooves are formed on both side surfaces of the metal member 1 to be joined, and the friction stir welding is performed by arranging a pair of joint members, but only one of them may be used. Moreover, the locus | trajectory and rotation direction which a rotation tool moves are not limited to an above-described form, What is necessary is just to set suitably. Further, in the joint member main joining step, it is not always necessary to stir the entire surface of the joint member. Moreover, the locus | trajectory of a rotation tool is an illustration, Comprising: A locus | trajectory is not limited.

It is the perspective view which showed the joining method which concerns on 1st embodiment. It is the figure which showed the joining method which concerns on 1st embodiment, Comprising: (a) is a perspective view, (b) is a top view. It is the side view which showed the rotation tool of the joining method which concerns on 1st embodiment, Comprising: (a) is a rotation tool for small joining, (b) is a rotation tool for medium-sized joining, (c) is for large joining. Indicates a rotation tool. It is the top view which showed the 1st main joining process which concerns on 1st embodiment. It is the II sectional view taken on the line of FIG. 4, Comprising: It is the figure which showed the 2nd main joining process which concerns on 1st embodiment. It is the perspective view which showed the ditch | groove formation process which concerns on 1st embodiment. It is the perspective view which showed the tab material arrangement | positioning process of the ditch | groove bottom face main joining process which concerns on 1st embodiment. It is the perspective view which showed the ditch | groove bottom surface main joining process which concerns on 1st embodiment. It is the figure which showed the 1st joint member arrangement | positioning process which concerns on 1st embodiment, Comprising: (a) is a perspective view, (b) is a top view. It is the top view which showed the 1st joint member temporary joining process which concerns on 1st embodiment. It is the top view which showed the 1st joint member main joining process which concerns on 1st embodiment. It is the II-II sectional view taken on the line of FIG. It is the top view which showed the 1st joint member main joining process which concerns on 2nd embodiment. It is the III-III sectional view taken on the line of FIG. It is the perspective view which showed the conventional joining method. It is the perspective view which showed the conventional joining method.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Metal member to be joined 1a 1st metal member 1b 2nd metal member 2 1st tab material 3 2nd tab material A Front surface B Back surface C 1st side surface D 2nd side surface F Small size rotating tool G Medium size rotating tool H Rotating tool for large joints j Unplasticized region J Butt portion K Concave groove Ka Concave groove width P1 Pilot hole R Tunnel-like cavity defect U Joint member W Plasticized region

Claims (6)

A joining method in which a rotating tool is moved to perform friction stirring,
A butting step of butting a pair of metal members;
A first main joining step in which friction stir is performed from the surface of the metal member to the abutting portion between the metal members;
A second main joining step in which friction agitation is performed from the back surface of the metal member to the abutting portion;
In the side surface of the metal member, a groove bottom bottom main joining step of performing frictional stirring along the abutting portion from the bottom surface of the groove formed along the abutting portion;
In the concave groove, a joint member arranging step of arranging a joint member covering the plasticized region formed in the first main joining step and the second main joining step,
A joint member main joining step in which friction agitation is performed on the abutting portion between the one metal member and the joint member and the abutting portion between the other metal member and the joint member. .   2. The joining method according to claim 1, wherein in the joint member main joining step, friction agitation is also performed on an abutting portion between a bottom surface of the concave groove and a lower surface of the joint member.   The joining method according to claim 2, wherein the tunnel-shaped cavity defect formed in the concave groove bottom surface main joining step is divided by friction stirring performed in the joint member main joining step.   In the plasticized region formed by the first main joining step and the second main joining step, it includes a first repairing step of sealing a tunnel-like cavity defect exposed on the bottom surface of the concave groove with a weld metal. The joining method according to any one of claims 1 to 3.   The width | variety of the said ditch | groove is larger than the width | variety of the plasticization area | region formed by said 1st main joining process and 2nd main joining process, The Claim 1 thru | or 4 characterized by the above-mentioned. Joining method.   The joining method according to any one of claims 1 to 5, wherein a pilot hole is formed in advance at a position where the rotating tool is to be inserted.

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