JP2008284607A - Joining method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a joining method for joining metal elements together at a butt section with high joint quality. <P>SOLUTION: The joining method includes a final joining step of joining metal members 1, 1 together at a butt section J1 between them by subjecting the butt section J1 to friction stirring effected by a rotation tool A. The joining method also includes a temporary joining step conducted before the final joining step. The temporary joining step includes joining the butt section J1 by forming, by deposit welding, a deposit section 5 projecting from the surfaces of the metal members 1, 1. In the final joining step, friction stirring is applied to the deposit section 5 formed in the temporary joining step. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

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

As a method for joining metal members (metal elements), friction stir welding (FSW = Friction Stir Welding) is known. In friction stir welding, the rotated rotating tool is moved along the abutting portion between the metal members, and the metal at the abutting portion is plastically flowed by the frictional heat between the rotating tool and the metal member, so that the metal members are solid-phased. It joins (for example, refer patent document 1, 2). In general, the rotating tool is formed by protruding a stirring pin (probe) on the lower end surface of a cylindrical shoulder portion.
JP 2003-164980 A JP 2005-66669 A

  By the way, in the conventional joining method using friction stirring, a part of the metal fluidized plastically by the frictional heat between the rotary tool and the metal member is discharged as burrs from the outer periphery of the rotary tool, and the metal in the plasticized region is discharged. Since there is a shortage of plasticity, the plasticized region sinks, forming a groove (dent) in the joint between the metal elements, and further forming a cavity in the plasticized region, resulting in a joint defect. .

  Then, an object of this invention is to provide the joining method which joins the butt | matching part of metal elements with high joining quality.

  The joining method according to claim 1 of the present invention is a joining method including a main joining step of joining the metal elements at the abutting portion by performing frictional stirring of the abutting portions between the metal elements with a rotary tool. Before the main joining step, the method includes a temporary joining step of forming a build-up portion raised above the surface of the metal element at the abutting portion by overlay welding and joining the abutting portion. Friction stirring is performed on the build-up portion formed in the joining step.

  According to this configuration, even if a part of the metal fluidized plastically in the main joining process is discharged as burrs from the outer periphery of the rotary tool, the build-up part formed in the temporary joining process is plasticized. Since the metal makes up for that, there will be no shortage of metal. For this reason, it is possible to prevent high-quality friction stir welding by preventing the formation of cavities in the plasticized region and bonding defects such as dents on the surface of the plasticized region.

  According to a second aspect of the present invention, the bonding method according to the first aspect further includes a groove forming step of forming a groove along the abutting portion before the temporary bonding step. The above-mentioned groove portion is formed by filling the groove by prime welding.

  According to this configuration, the contact area between the surface of the groove formed in the metal element and the molten metal of the welding material is increased compared to the case where the molten metal is overlay welded to the surface of the metal element. The joining force with the raised portion is increased. Therefore, in this main joining process, peeling from the metal element of a build-up part can also be prevented by the frictional force by a rotary tool.

  According to a third aspect of the present invention, in the first or second aspect, in the temporary bonding step, the build-up portion that is continuous along the abutting portion is formed. According to this configuration, since the height of the build-up portion is substantially constant, the rotary tool can be moved along the abutting portion (build-up portion) at a substantially constant height.

  According to a fourth aspect of the present invention, in the first or second aspect, in the temporary joining step, the build-up portion is formed discontinuously along the abutting portion. According to this structure, the metal for overlay welding can be reduced. In addition, since the metal of the build-up portion moves also to the abutting portion where the build-up portion is not formed, there is no shortage of metal.

  According to a fifth aspect of the present invention, in any one of the first to fourth aspects, the tab material is disposed on both sides of the abutting portion before the temporary joining step. A tab material arranging step for abutting the metal element and the tab material, and in the temporary joining step, the metal element and the surface of the tab material so as to be continuous from the built-up portion formed in the abutting portion. The tab build-up portion raised from the tab material is formed on the tab material, and in the main joining step, the main joining step set on the other side of the tab building-up portion from the start position of the main joining step set on one side of the tab building-up portion. Friction stirring is performed along the abutting portion to the end position of the process.

  According to this configuration, since the rotary tool is not inserted / removed at the abutting portion, a joining defect due to the insertion / removal of the rotating tool is not formed at the abutting portion. In addition, because the tab build-up part was formed on the tab material, even if a part of the plastic fluidized metal was discharged as burrs from the outer peripheral part of the rotary tool due to frictional heat between the rotary tool and the metal member, Since the metal of the build-up portion and the tab build-up portion compensates for that, and the metal at the end of the butted portion is not insufficient, it is possible to prevent a joint defect at the end of the butted portion.

  A joining method according to a sixth aspect of the present invention is the method according to any one of the first to fifth aspects, wherein the rotary tool is inserted at a start position between the temporary joining step and the main joining step. And a pilot hole forming step of forming a pilot hole. According to this configuration, in the main joining step, the stirring pin of the rotary tool can be reliably inserted at the start position.

  In the joining method according to claim 7 of the present invention, in any one of claims 1 to 6, in the temporary joining step, the build-up portion is formed on one surface of the metal element. A first forming step and a second forming step of forming the build-up portion on the other surface of the metal element, and the main bonding step includes the meat formed in the first forming step. A first friction agitation step for performing friction welding on the embossed portion, and a second friction agitation step for performing friction welding on the surfacing portion formed in the second forming step. Performing the first and second friction agitation steps so that the plasticized region formed by the step and the plasticized region formed by the second friction agitation step overlap at the center in the thickness direction of the metal element. It is characterized by.

  According to this configuration, temporary joining is performed on the front and back surfaces of the metal elements, friction stir as main bonding is performed on the front and back surfaces, the metal elements are bonded to each other from the front and back surfaces, and plasticized regions formed from the front and back surfaces, respectively. Since they overlap each other, the metal elements can be joined without a gap.

  The joining method according to claim 8 of the present invention is a joining method in which the metal elements are joined to each other at the abutting portion by friction-stirring the abutting portions between the metal elements with a rotary tool, and one of the metal elements A first temporary joining step of forming, on the abutting portion of the surface, a first build-up portion raised from the one surface by overlay welding, and joining the abutting portion from the one surface; A first friction agitation step of performing friction agitation on the first build-up portion formed in the first temporary joining step and joining the metal elements from the one surface at the abutting portion; and the metal A second build-up portion raised from the other surface is formed by overlay welding on the abutting portion of the other surface on the back side of the one surface of the element, and the abutting portion is formed from the other surface. Formed by the second temporary joining step to be joined and the second temporary joining step. A second friction agitation step of performing friction agitation on the second build-up portion and joining the metal elements to each other at the abutting portion from the other surface, and is formed in the first friction agitation step. The friction stir is performed so that the plasticizing region and the plasticizing region formed in the second friction stirring step overlap at the central portion in the thickness direction of the metal element.

  According to this configuration, temporary joining is performed on the front and back surfaces of the metal elements, friction stir as main bonding is performed on the front and back surfaces, the metal elements are bonded to each other from the front and back surfaces, and plasticized regions formed from the front and back surfaces, respectively. Since they overlap each other, the metal elements can be joined without a gap.

  According to the joining method according to the present invention, the abutting portions between metal elements can be joined with high joining quality.

  As the best mode for carrying out the present invention, a stirring pin (probe) is inserted into a butt portion between metal members (metal elements), and the stirring pin and the metal member are relatively moved while rotating the stirring pin. A joining method for joining the metal members to each other by performing frictional stirring on the abutting portion will be described.

In this embodiment, as shown in FIG. 1, the case where the metal members 1 and 1 are connected linearly is illustrated.
First, the metal members 1 and 1 to be joined will be described in detail, and the first tab member 2 and the second tab member 3 used when joining the metal members 1 and 1 will be described in detail.

  The metal member 1 is made of a metal material that can be frictionally stirred, such as aluminum, aluminum alloy, copper, copper alloy, titanium, titanium alloy, magnesium, and magnesium alloy. In the present embodiment, one metal member 1 and the other metal member 1 are formed of metal materials having the same composition. Although there is no restriction | limiting in particular in the shape and dimension of the metal members 1 and 1, It is desirable to make the thickness dimension in the abutting part J1 the same at least.

  The first tab member 2 and the second tab member 3 are arranged so as to sandwich the abutting portion J1 of the metal members 1 and 1, and are attached to the metal members 1 and 1, respectively. The seam (boundary line) of the metal members 1 and 1 appearing on the side surface 14 side is covered. 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 metal member 1. FIG. Moreover, 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 thickness dimension is made the same with the thickness dimension of the metal member 1 in the abutting part J1. Yes.

  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 preparation step and (2) a friction stir welding step (main joining step).

(1) Preparation process:
First, the preparation process will be described with reference to FIG. The preparation step is a step of preparing the metal members 1 and 1 and the contact members (first tab member 2 and second tab member 3) to be joined in a state capable of friction stir welding, (1-1) a butt step, (1-2) tab material arranging step, (1-3) welding step, (1-4) groove forming step, (1-5) temporary joining step, and (1-6) pilot hole forming step.

  (1-1) The abutting step is a step of abutting the metal members 1 and 1 to be joined. As shown in FIG. 1C, the side surface 11 of the other metal member 1 is brought into close contact with the side surface 11 of the one metal member 1, and the surface 12 of the one metal member 1 and the surface 12 of the other metal member 1. Further, the back surface 13 of one metal member 1 and the back surface 13 of the other metal member 1 are flush with each other.

  (1-2) The tab material arranging step is a step of arranging the first tab material 2 and the second tab material 3 on both sides of the abutting portion J1 of the metal members 1,1. As shown in FIG. 1B, the first tab member 2 is disposed on one end side of the abutting portion J1 of the metal members 1 and 1, and the abutment surface 21 is placed on the side surfaces 14 and 14 of the metal members 1 and 1, respectively. At the same time, the second tab member 3 is disposed on the other end side of the abutting portion J1, and the contact surface 31 is contacted with the side surfaces 14, 14 of the metal members 1, 1. At this time, as shown in FIG. 1 (d), the surface 22 of the first tab member 2 and the surface 32 of the second tab member 3 are flush with the surface 12 of the metal member 1, and the first tab member 2 The back surface 23 and the back surface 33 of the second tab member 3 are flush with the back surface 13 of the metal member 1.

  (1-3) The welding process is a process of temporarily joining the first tab member 2 and the second tab member 3 to the metal members 1 and 1 by welding. As shown in FIGS. 1A and 1B, the corners 2a and 2a formed by the metal member 1 and the first tab member 2 (that is, the side surface 14 of the metal member 1 and the first tab member 2). The corners 2a, 2a) formed by the side surfaces 24 are welded to join the metal member 1 and the first tab member 2, and the corners 3a formed by the metal member 1 and the second tab member 3 are joined. , 3a (that is, the corners 3a, 3a formed by the side surface 14 of the metal member 1 and the side surface 34 of the second tab member 3) are welded to join the metal member 1 and the second tab member 3 together. In addition, welding may be performed continuously over the entire length of the corners 2a and 3a, or welding may be performed intermittently.

  (1-4) The groove forming step is a step of forming grooves 4 (grooves 41, 42, and 43) along each of the abutting portion J1 and the tab abutting portions J2 and J3, as shown in FIG. After the welding process, the groove 42 and the groove 43 are formed by, for example, an end mill along the tab abutting portion J2 and the tab abutting portion J3. Further, the tab abutting portion J2 and the tab abutting portion J3 are crossed along the abutting portion J1, and the groove 41 along the abutting portion J1 is formed. As shown in FIG. 4, the widths α of the grooves 41, 42, and 43 are preferably 26% to 90% of the diameter β of the shoulder portion A <b> 1 of the rotary tool A. Further, the groove 41 and the grooves 42 and 43 intersect with each other at the tab abutting portions J2 and J3. Moreover, the groove | channel 4 formed at this groove | channel formation process is formed in the cross-sectional substantially V shape which made the abutting part J1 the vertex, as shown in FIG.

  (1-5) As shown in FIG. 3, the temporary joining step performs build-up welding on the grooves 41, 42, 43 (see FIG. 2) formed in the groove forming step, so that the metal member 1, the first tab This is a step of forming the built-up portion 5 that is raised above the surfaces 12, 22, 32 of the material 2 and the second tab material 3, thereby joining the abutting portion J1 and the tab abutting portions J2, J3.

  Here, in the built-up portion 5 formed by being built up in the groove 41, a portion of the butted portion J1 is represented as a butted built-up portion 51a, and the first tab member 2 is continuous with the butted built-up portion 51a. The formed portion is represented as a tab build-up portion 51b, and similarly, the portion formed on the second tab member 3 so as to be continuous with the butted build-up portion 51a is represented as a tab build-up portion 51c. Further, the portion where the groove 42 formed in the tab butting portion J2 is built up is represented as a joint build-up portion 52a, 52b, and the portion where the groove 43 formed in the tab fitting portion J3 is built up is a joining built-up portion 53a, 53b. Let's represent.

  As shown in FIG. 4 and FIG. 5A, the build-up portion 5 has a volume filling the groove 4 and a part of the plastic fluidized metal discharged as burrs from the outer peripheral portion of the rotary tool. And a thickness including at least a volume that compensates for the minute. That is, the volume of the built-up portion 5 is preferably larger than the sum of the volume of the groove 4 and the volume in which a part of the plastic fluidized metal is discharged as burrs from the outer peripheral portion of the rotary tool. Moreover, since the plastic fluidized metal also moves on the surface 12 on the side of the built-up portion 5, it is desirable to form the built-up portion 5 thick in consideration of that amount. Further, it is desirable that the width α of the built-up portion 5 is 26% to 90% of the diameter β of the shoulder portion A1. The overlay welding may be performed by, for example, TIG (Tungsten Inert Gas Arc Welding) welding or MIG (Metal Inert Gas Arc Welding) welding. Moreover, although the welding material of the build-up part 5 may differ from the metal member 1, it demonstrates here that it is the same.

  (1-6) The pilot hole forming step is a step of forming the pilot hole 6 at the end of the built-up portion 5 formed in the first tab member 2 as shown in FIGS. 3 and 4. This pilot hole 6 is a hole for inserting the stirring pin A2 of the rotating tool A at the friction stirring start position S set in the first tab member 2, and the insertion resistance (press-fit resistance) of the stirring pin A2 of the rotating tool A ) Is provided for the purpose of reducing. The pilot hole 6 is formed by drilling with a drill (not shown). Although there is no restriction | limiting in particular in the form of this prepared hole 6, In this embodiment, it is cylindrical. Further, it is desirable that the depth γ of the prepared hole 6 is formed to be shorter than the length δ of the stirring pin A2.

  In this embodiment, the friction stirring start position S is provided at the abutting portion J1 located on the first tab member 2 side, and the end position E is provided on the second tab member 3, but the start position S and end position are provided. It is not intended to limit the position of E. For example, the start position S and the end position E may be provided at appropriate positions of the abutting portion J1. In this case, the first tab material 2 and the second tab material 3 may be omitted. Similarly, in the present embodiment, the pilot hole 6 is formed in the first tab member 2, but the position of the pilot hole 6 is not particularly limited, and may be formed in the second tab member 3, or the tab. It may be formed at the abutting portions J2 and J3, and preferably it is formed on the extended line of the joint (boundary line) of the metal members 1 and 1 appearing on the surface 12 side of the metal member 1 as in this embodiment. . The inner diameter of the pilot hole 6 is smaller than the maximum outer diameter (upper end diameter) of the stirring pin A2 of the rotary tool A.

  When the preparation process is completed, the metal members 1, 1, the first tab material 2 and the second tab material 3 are placed on a frame of a friction stirrer (not shown) and cannot be moved using a jig (not shown) such as a clamp. To be restrained. In addition, when a welding process is abbreviate | omitted, a butt | matching process and a tab material arrangement | positioning process are performed on the stand of the friction stirring apparatus which is not shown in figure.

(2) Friction stir welding process (main joining process):
Next, the friction stir welding process according to this embodiment will be described in detail. The friction stir welding step is a step in which the abutting portion J1 is friction agitated by the rotary tool A and the metal members 1 and 1 are joined at the abutting portion J1. Therefore, first, with reference to FIG. 4 and FIG. 5, the rotary tool A provided with the stirring pin A2 for performing frictional stirring will be described in detail.

  The rotary tool A shown in FIG. 4 is made of a metal material harder than the metal member 1 such as tool steel, and has a columnar shoulder portion A1 and a lower end surface A11 of the shoulder portion A1 ((b) of FIG. 5). And a protruding stirring pin A2. What is necessary is just to set the dimension and shape of the rotation tool A according to the material, thickness, etc. of the metal member 1.

  The lower end surface A11 of the shoulder portion A1 is a part that plays a role of preventing plastic scattering by pressing the plastic fluidized metal, and is formed in a concave shape in this embodiment. There is no restriction | limiting in particular in the magnitude | size of the outer diameter of shoulder part A1.

  The stirring pin A2 hangs down from the center of the lower end surface A11 of the shoulder portion A1, and is formed into a tapered truncated cone shape in this embodiment. Further, a stirring blade (not shown) engraved in a spiral shape is formed on the peripheral surface of the stirring pin A2.

  Next, the principle of friction stirring by the stirring pin A2 of the rotary tool A will be described. First, as shown in FIG. 4, the rotary tool A is positioned immediately above the pilot hole 6 (starting position S) formed on the first tab member 2 side, and then the rotary tool A is lowered while rotating and stirred. The pin A2 is pressed against the start position S. When the stirring pin A2 comes into contact with the inner peripheral surface of the pilot hole 6 of the abutting portion J1, the metal around the stirring pin A2 is plastically fluidized by frictional heat and inserted into the first tab member 2.

  Then, the rotating tool A moves along the abutting portion J1, and as shown in FIG. 5B, the metal W around the stirring pin A2 is plastically fluidized by frictional heat. The rotational speed of the rotary tool A is set according to the size and shape of the agitating pin A2, the material of the metal member 1 and the like that are frictionally agitated, the thickness, and the like. The plastic fluidized metal W ((b) in FIG. 5) generated when the rotary tool A passes is cured again and returned to its original state. Here, for convenience, it is referred to as a plasticized region W1 (see FIGS. 6 and 7).

  Next, the state in the depth direction of the abutting portion J1 in the friction stir welding process will be described. First, as shown in FIG. 7 (a), the rotary tool A is positioned immediately above the start position S (the pilot hole 6), and then the rotary tool A is rotated clockwise and lowered to start the stirring pin A2. Position to position S. And the front end side of the stirring pin A2 of the rotating tool A is inserted into the prepared hole 6 while rotating (see FIG. 4), and the metal fluidizes plastically from the inner peripheral surface of the prepared hole 6. In such a state, the agitating pin A2 is press-fitted while the plastic fluidized metal to which a downward force is applied is pushed away by the peripheral surface of the agitating pin A2.

  Further, when the entire stirring pin A2 enters the tab build-up portion 51b of the first tab member 2 and the entire lower end surface A11 of the shoulder portion A1 becomes the same height as the surface 22 of the first tab member 2 ( 4), relatively rotating the rotating tool A (stirring pin A2) toward the abutting portion J1 of the metal members 1 and 1 while performing frictional agitation, and further, as shown in FIG. The butt build-up portion 51a on the butt portion J1 side is frictionally stirred across the portion J2 (see FIG. 6). Therefore, as described above, when the rotary tool A is moved, the metal around the stirring pin A2 is changed to the plastic W that has been plastically fluidized, and plastic fluidized at a position away from the stirring pin A2. The metal W hardened again and returned to its original state. Here, for convenience, it is referred to as a plasticized region W1 (see FIGS. 6 and 7).

  Subsequently, as shown in FIG. 7C, the rotary tool A plastically deforms the metal of the second tab member 3 across the tab abutting portion J3 of the metal member 1, the second tab member 3, and the abutting portion J1. When it is moved while changing to the conversion region W1 and reaches the end position E, it is raised while being rotated and the stirring pin A2 is removed from the end position E. If the stirring pin A2 is separated upward at the end position E, a hole 8 having the same shape as the stirring pin A2 is inevitably formed. Further, since the agitating pin A2 is never detached during the friction agitation, the surface of the plasticized region is a one-stroke movement trajectory (bead).

  Therefore, according to the present embodiment, even if a part of the metal fluidized plastically in the friction stir welding process is discharged from the outer peripheral portion of the rotary tool A as burrs, the build-up portion 5 is plastically fluidized. Since the metal makes up for that, there will be no shortage of metal. Therefore, formation of depletion in the plasticized region W1 and bonding defects such as dents on the surface of the plasticized region can be prevented, and high-quality friction stir welding can be performed.

[Modification 1]
In this embodiment, as shown in FIG. 4 in particular, the case where the groove 4 has a substantially V-shaped cross section has been described. However, the shape may be any shape. For example, as shown in FIG. 8A, a groove 4a having a substantially U-shaped cross section is formed in the abutting portion J1 between the metal members 1 and 1, and a built-up portion 5a is formed in the groove 4a. May be. The same applies to the tab abutting portions J2 and J3. Further, as shown in FIG. 8 (b), a groove 4b having a substantially rectangular cross section is formed in the abutting portion J1 of the metal members 1 and 1, and a built-up portion 5b is formed in the groove 4b. Good.

[Modification 2]
In this embodiment, it has been described that only one surface 12 of the metal member 1, 1 is friction stir welded, but both surfaces may be friction stir welded in order. In this case, as shown in FIG. 9, on the surface 12, grooves are formed in the abutting portion J1 and the tab abutting portions J2 and J3 to form the built-up portion 5 (first temporary joining step), and friction stirring is performed. (First friction stirring step). And as shown to (a) of FIG. 9, also on the back surface side, the groove part is formed in the butt | matching part J1 and tab butt | matching part J2, J3, and the build-up part 5R which raised from the surface 22R, 32R is formed ( After the second temporary joining step), friction stirring is performed with the rotary tool A from the start position SR to the end position ER (second friction stirring step). Here, the configuration corresponding to the same configuration in the first friction agitation step is distinguished by attaching “R” to the configuration in the second friction agitation step.

  Also in the second friction stirring step, as shown in FIG. 9B, the plastic fluidized metal WR is cured to form a plasticized region W1R, and the abutting portion J1 is joined from the back surface. At this time, the friction stir is performed so that the plasticizing region W1 generated in the first friction stirring step and the plasticizing region W1R generated in the second friction stirring step overlap at the center in the thickness direction of the metal member 1. Then, as shown in FIG. 9C, the abutting portion J1 is completely joined from the front and back. Then, the rotary tool A is taken out from the end position ER of the second tab member 3 to complete the joining. At this time, a hole 8R is formed as a trace of the stirring pin A2.

  As shown in FIG. 9A, the start position SR (the lower hole 6R) of the second friction stirring process is located above the through hole 8 of the rotary tool A remaining in the first friction stirring process. The reason for this is to prevent the metal plasticized in the second friction stirring step from moving through the hole 8.

[Modification 3]
Further, the temporary joining step including the first forming step and the second forming step, and the main joining step including the first friction stirring step and the second friction stirring step are performed in this order. Also good. In this case, in the second forming step, since the build-up portion 5 is formed in the first forming step, auxiliary members (not shown) are arranged on both sides of the build-up portion 5 so that the build-up portion 5 is obstructive. It is necessary not to become.

[Modification 4]
In this embodiment, the groove forming step has been described as being performed between the welding step and the temporary joining step. However, when the shape of the metal member 1, 1 is molded, the end of the metal member 1, 1 is The groove may be formed by the surface that has been scraped over the entire length and scraped off when the metal elements are brought into contact with each other. For example, if the end portion is cut obliquely, a groove having a V-shaped cross section can be formed between the oblique planes by joining two metal materials. Further, a groove forming step may be included before the abutting step. In this case, in the abutting step, the extruded shape member in which the groove is formed is used as the metal members 1 and 1.

[Modification 5]
In this embodiment, the structure in which the butt build-up portion 51a and the tab build-up portions 51b and 51c and the joint build-up portions 52a, 52b, 53a, and 53b intersect and are continuously connected has been described. It is good also as a structure discontinuously spaced apart. In this case, the amount of metal used for overlay welding is small.

[Modification 6]
In this embodiment, the joining between the plate-like metal members 1 has been described, but the same can be done when joining the hollow members. In the friction stir welding, the rotation direction of the rotary tool A may be right rotation or left rotation.

It is a figure for demonstrating arrangement | positioning of the metal member which concerns on embodiment, a 1st tab material, and a 2nd tab material, Comprising: (a) is a perspective view, (b) is a top view, (c) is (b). II sectional view taken on the line, (d) is a sectional view taken along the line II-II of (b). It is a top view for demonstrating the groove | channel formation process of embodiment. It is a top view for demonstrating the temporary joining process of embodiment. It is a figure for demonstrating the structure of the rotary tool of embodiment, and the mode at the time of the start of a friction stirring process, Comprising: It is the IV-IV sectional view taken on the line of FIG. It is a figure for demonstrating the mode of the butt | matching part in the friction stirring process of embodiment, Comprising: (a) is the VV sectional view taken on the line of FIG. 3 which shows the mode before the friction stirring of a butt | matching part, (b) is. It is sectional drawing equivalent to the VI-VI line cross section of FIG. 6 which shows the mode after friction stirring of a butt | matching part. It is a top view for demonstrating the friction stirring process of embodiment. It is sectional drawing for demonstrating the friction stirring process of embodiment, Comprising: (a) is sectional drawing equivalent to the III-III sectional view of FIG. 3 which shows the mode at the time of friction stirring start, (b) is friction stirring implementation. Sectional drawing equivalent to the III-III line | wire cross section of FIG. 6 which shows an inside state, (c) is sectional drawing which shows the mode at the time of completion | finish of friction stirring. It is a figure which shows the modification of the groove | channel formed in the groove | channel formation process of embodiment, (a) is sectional drawing which shows a groove | channel with a substantially U-shaped cross section, (b) is sectional drawing which shows a groove | channel with a substantially rectangular cross section. is there. It is sectional drawing for demonstrating the modification of the friction stirring process of embodiment, Comprising: (a) is sectional drawing equivalent to (a) of FIG. 7 which shows the mode at the time of friction stirring start, (b) is friction stirring. FIG. 8B is a cross-sectional view corresponding to FIG. 7B showing the state during implementation, and FIG. 8C is a cross-sectional view corresponding to FIG.

Explanation of symbols

1 Metal member (metal element)
2 1st tab material 3 2nd tab material 4 Groove 5 Overlaying part 51a Butting overfilling part (overlaying part)
51b Tab build-up part 51c Tab build-up part 52a Joining build-up part 52b Joining build-up part 53a Joining build-up part 53b Joining build-up part 6 Pilot hole J1 butt part J2 Tab butt part J3 Tab butt part A Rotating tool A1 Shoulder part A2 Stirring pin P1 Pilot hole W Plastic fluidized metal W1 Plasticization region

Claims (8)

It is a joining method including a main joining step of joining the metal elements at the abutting portion by friction stirring the abutting portions between the metal elements with a rotating tool,
Before the main joining step, including a provisional joining step of joining the abutting portion by forming an overlaid portion raised from the surface of the metal element in the abutting portion by overlay welding,
In the main joining step, a friction stir is performed on the build-up portion formed in the temporary joining step. Furthermore, before the temporary joining step, including a groove forming step of forming a groove along the abutting portion,
The joining method according to claim 1, wherein, in the temporary joining step, the build-up portion is formed by filling the groove by build-up welding.   The joining method according to claim 1, wherein in the temporary joining step, the build-up portion that is continuous along the abutting portion is formed.   The joining method according to claim 1 or 2, wherein in the temporary joining step, the build-up portion is formed discontinuously along the abutting portion. Before the temporary joining step, including a tab material arranging step of arranging tab materials on both sides of the abutting portion and abutting the metal element and the tab material,
In the temporary joining step, the tab build-up portion raised from the surface of the metal element and the tab material is formed in the tab material so as to be continuous from the build-up portion formed in the butt portion,
In the main joining step, friction stirring is performed along the abutting portion from the start position of the main joining step set to one of the tab build-up portions to the end position of the main joining step set to the other of the tab build-up portions. The joining method according to any one of claims 1 to 4, wherein the joining method is characterized in that:   6. The pilot hole forming step of forming a pilot hole for inserting a rotary tool at a starting position between the temporary bonding step and the main bonding step. 2. The joining method according to item 1. In the temporary joining step, a first forming step of forming the build-up portion on one surface of the metal element, and a second forming step of forming the build-up portion on the other surface of the metal element; Contains
In the main joining step, friction joining is performed on the first friction stirrer step in which friction welding is performed on the build-up portion formed in the first formation step, and on the build-up portion formed in the second formation step. A second friction stirring step to be performed,
Friction agitation is performed so that the plasticized region formed by the first friction agitation step and the plasticized region formed by the second friction agitation step overlap at the center in the thickness direction of the metal element. The joining method according to any one of claims 1 to 6. A joining method of joining the metal elements at the abutting part by performing friction stirring on the abutting part between the metal elements by a rotating tool,
A first build-up portion raised from the one surface is formed by overlay welding at the abutting portion of one surface of the metal element, and the first portion is joined from the one surface. A temporary joining step;
A first friction stirring step of performing friction stirring on the first build-up portion formed in the first temporary bonding step and bonding the metal elements from the one surface at the abutting portion;
A second build-up portion raised from the other surface is formed by overlay welding on the abutting portion on the other surface on the back side of the one surface of the metal element, and the abutting portion is formed on the other surface. A second temporary joining step for joining from the surface;
Including a second friction stirring step of performing friction stirring on the second build-up portion formed in the second temporary bonding step and bonding the metal elements from the other surface at the abutting portion;
Friction agitation is performed so that the plasticized region formed in the first friction agitation step and the plasticized region formed in the second friction agitation step overlap at a central portion in the thickness direction of the metal element. A characteristic joining method.

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