JP2003181655A - Friction stir welding method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for friction stir welding capable of welding two aluminum plates advantageously without forming a projection of a mark which is made by drawing out a pin of a rotation tool. <P>SOLUTION: A cylindrical rod tool, which has one flatten surface of the tip 17 in the axial direction and a concave part 18 on the tip surface or a concave spherical surface of the tip, is rotated around the axis with the posture to which it inclined back to the direction for relatively moving to the butt part and the laminating part of the two aluminum materials 10, 12, or which it inclined to the laminating direction of the two aluminum materials, and at the same time, the cylindrical rod tool is inserted to the butt part, the laminating part 22, or a corner, and moved relatively, and on the other hand, the friction stir welding process is done under the condition satisfying with the specific relation of the thickness and the diameter of the two aluminum materials and the depth of inserting the rod tool. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a friction stir welding method, and more particularly, to butt welding and superposition welding of two aluminum materials,
Furthermore, the present invention relates to a friction stir welding method in which lap fillet welding is performed by a friction stir welding operation.

[0002]

BACKGROUND ART In recent years, US Pat. No. 5,460,317 has been proposed as one of the methods for joining aluminum materials by utilizing frictional heat.
Friction Stir Welding as disclosed in Japanese Patent Publication No. 7-505090
However, it is receiving attention. Then, in the field of processing aluminum materials, etc., butt welding, superposition welding, or superposition fillet welding of aluminum materials by this friction stir welding method is generally performed with a material harder than the two aluminum materials to be joined. This is carried out by using a rotating jig in the shape of a rod-shaped jig in which a pin is provided at the center of the tip.

That is, for example, when two aluminum materials having a plate shape, a rod shape, or a pipe shape are butt-joined together by using the friction stir welding method, a rotary jig provided with a pin at the center of the tip is used. While rotating the tool at high speed, insert the pin at the tip into the abutting part of the two aluminum materials and move them relatively, so that the pin or rotating jig and the abutting part of the two aluminum materials can be rotated. Generate frictional heat between
Then, the frictional heat makes the peripheral portion of the butted portion plastically workable, and the agitating action by the high speed rotation of the pin causes the structure of the butted portion to intermingle with each other, without causing melting. It is joining two aluminum materials.

Further, in the superposition joining of aluminum materials having the above-mentioned shape by the friction stir welding method, one of the two aluminum materials is superposed on the other, while the tip of the rotary jig which is rotated at a high speed. The two aluminum materials are melted in the same manner as in the butt-joining, by inserting the pin into the superposed portion of the two aluminum materials, inserting the one aluminum material, and moving the pin relatively. Instead, they join at the superposed portion.

Further, when performing superposition fillet joining of aluminum materials having the above-mentioned shape by the friction stir welding method, one of the two aluminum materials is superposed on the other, and Insert the pin at the tip of the rotating jig that is rotated at high speed into the fillet formed between the overlapping surface of the other aluminum material and the side surface of the other aluminum material. By relatively moving, the two aluminum materials are integrally joined at the fillet portion without being melted, as in the butt joining and the superposition joining.

In butt joining, superposition welding, or superposition fillet welding of aluminum materials using such a friction stir welding method, the heat input to the aluminum materials is small and the strength and distortion of the joints are reduced. The advantage is that it can be made as small as possible.

However, when the conventional friction stir welding method for aluminum materials is carried out, a rotary jig is attached to the butted portion, the overlapped portion, or the joint portion formed along the fillet portion of the joined aluminum materials. Inevitably, a projection consisting of the withdrawal trace of the pin will be formed.
There were various problems.

That is, when the joined aluminum material is pressed, for example, with the projections formed by such pin withdrawal marks left as it is, stress concentration is caused at the projections, and during the press molding, There is a risk that cracks may originate from the projections, and when it is used as an automobile outer plate, there is a fear that the strength may be reduced at the projection formation site. Therefore, when the aluminum materials are joined by such a conventional friction stir welding method, after the friction stir welding operation is completed, an extra work such as removal of the projections formed by the pin withdrawal marks must be performed. It didn't happen.

[0009]

The present invention has been made in view of the circumstances as described above, and a problem to be solved by the invention is that when a friction stir welding of an aluminum material is performed, It is an object of the present invention to provide a method capable of advantageously eliminating the formation of protrusions formed by the withdrawal traces, and thus effectively omitting the protrusion removal work after the friction stir welding operation is completed.

[0010]

According to the present invention, in order to solve such a problem, two aluminum materials to be joined are butted, and a rotating jig is rotated with respect to the butted portion, and a tip portion thereof is rotated. At the time of friction stir welding of the butt portion by inserting the tip and moving it relative to each other, the rotating jig has a cylindrical shape, and a recess is provided on one end face in the axial direction, Using a rod-shaped jig in which a portion of the surface other than the portion where the recess is formed is a flat surface, the rod-shaped jig is rotated around the axis in a posture in which the rod-shaped jig is inclined rearward with respect to the relative movement direction with respect to the abutting portion. While being rotated, the concave portion is inserted into the abutting portion at one tip portion provided on the tip surface and relatively moved, and the following equation: (t ₁ + t ₂ ) / 2−r · sin θ <1 r ≦ 15 , Θ ≦ 5 [where, t ₁ and t ₂ : thickness or diameter (mm) of each of the two aluminum materials to be joined, r: radius (mm) of rod-shaped jig, θ: rod-shaped cure The gist of a friction stir welding method is characterized in that the friction stir welding operation is performed under the condition that the rearward inclination angle (°) of the tool is satisfied.

That is, in the friction stir welding method according to the present invention, since the rod-shaped jig to be inserted into the abutting portion of the two aluminum materials to be welded is provided with the concave portion, The contact area of the rod-shaped jig with respect to the aluminum material can be advantageously increased, and the tip end surface of the rod-shaped jig can be made to have a roughened shape as a whole, whereby the rod-shaped jig to be rotated is rotated. The peripheral portion of the butt portion, which is plastically workable by the friction heat generated between the tool and the butt portion of the two aluminum materials, is rotated by the rod-shaped jig due to the tip surface of the rod-shaped jig. As a result, the tissues around the abutting part are also sufficiently intermingled, and the two aluminum materials are not melted and are thus securely mixed. It become a fact that can be joined to.

Further, in the friction stir welding method according to the present invention, unlike the conventional method using the rotating jig having the pin at the center of the tip, the rod-shaped jig used as the rotating jig is butted. Since there is no pin on the tip surface of the tip surface on the side to be inserted into the portion other than the recess forming portion, the pin is not provided on the joint portion formed along the abutting portion. The formation of the protrusions formed by the extraction traces can be advantageously eliminated.

Moreover, the method of the present invention is provided in the conventional rotary jig because the friction stir welding operation is performed under the condition that all of the above three expressions are satisfied. Despite the fact that the tip of a rod-shaped jig having a larger diameter than that of the pin is inserted into the abutting part, the friction stir welding operation can be performed smoothly and As a result, a good joint can be formed.

Therefore, according to the friction stir welding method according to the present invention as described above, two aluminum materials that are butted against each other are formed with a protrusion formed by a pull-out trace of the pin of the rotary jig at the joint. Without the need for reliable and smooth joining, and as a result, after the friction stir welding operation has been completed, it can be advantageously freed from the extra work of removing the projections of the pin withdrawal marks. Therefore, the workability at the time of friction stir welding of the aluminum material can be improved extremely advantageously.

Further, in the present invention, in order to solve the above-mentioned technical problem, one of two aluminum materials to be joined is superposed on the other while rotating with respect to the overlapping portion. While rotating the jig, at the tip of the jig, penetrate and insert one of the aluminum materials,
When friction stir welding is performed on the overlapped portion by moving it relatively, the rotary jig has a cylindrical shape, and a recess is provided on one end face in the axial direction, and the end face is formed. In the rod-shaped jig in which a portion other than the portion where the recess is formed is a flat surface, the rod-shaped jig is rotated around the axis in a posture in which the rod-shaped jig is tilted backward with respect to the relative moving direction with respect to the overlapping portion. While being rotated, the concave portion is inserted into the overlapping portion at one tip portion provided on the tip surface and relatively moved, and the following equation: t ₁ −r · sin θ <1 r ≦ 15, θ ≦ 5 [where t ₁ is the thickness or diameter (mm) of the aluminum material located on the upper side of the two aluminum materials to be joined in the stacked state, r is the radius of the rod-shaped jig ( mm), θ: Backward tilt angle of rod-shaped jig ( )] Under the conditions that satisfy the, friction stir welding method characterized by performing the friction stir welding operation also it is for its gist.

Even in the friction stir welding method according to the present invention as described above, the rod-shaped jig to be inserted into the superposed portion of the two aluminum materials to be joined is provided with a recess at the tip end surface thereof, and the rod-like jig is provided with such a recess. The contact area of the rod-shaped jig tip surface with the aluminum material is increased, and the rod-shaped jig tip surface is roughened. Unlike the conventional method using a rotating jig having a pin at the center of the tip, the overlapping portion is different from the conventional method in that the portion other than the formation portion is flat and no pin is provided on the tip surface. It is possible to advantageously eliminate the formation of a protrusion formed by a pin withdrawal at a joint formed along the rod-shaped jig. Accompanying the rotation of Te, the superimposed portion surrounding site, which is plasticized by contacting the rod-shaped jig tip surface is obtained is allowed to well-stirred, the two aluminum material, without melting, which as it can be securely bonded.

Moreover, the method of the present invention is provided in the conventional rotary jig because the friction stir welding operation is carried out under the condition that all of the above three expressions are satisfied. Although the tip of a rod-shaped jig having a larger diameter than that of the pin is inserted into the abutting portion, friction stir welding operation can be performed smoothly and the overlapping portion Along the way, a good joint can be formed.

Therefore, even by the friction stir welding method according to the present invention, two aluminum materials to be superposed on each other can be formed without forming any protrusion at the joint portion thereof, which is formed by the pull-out trace of the pin of the rotary jig. , Reliable and smooth joining, and as a result,
The work of removing such protrusions after the completion of the friction stir welding operation can be advantageously omitted, and the workability of the friction stir welding of the aluminum material can be effectively enhanced.

In the friction stir welding method according to the present invention, when a rod-shaped jig having a recess on one end face in the axial direction is used as a rotating jig, the recess is preferably 2 mm. It has the following depth and is provided on one end surface of the rod-shaped jig. As a result, the rod is attached to the plasticized portion (the peripheral portion of the butt portion or the peripheral portion of the overlapped portion) of the two aluminum materials that are in a state capable of being plastically worked by contacting the tip end surface of the rod-shaped jig that is rotated. The stirring action by the distal end surface of the jig can be enhanced more advantageously, and therefore, superior joining quality can be effectively secured in the joining portion of the two aluminum materials.

Further, in the friction stir welding method according to the present invention, when a rod-shaped jig having a recess on one end face in the axial direction is used as a rotary jig, it is desirable that such a recess be a rod-shape. It has a side wall extending in the circumferential direction of the jig and is provided on one end surface of the rod-shaped jig.

If such a construction is adopted, the metal around the abutting portion, which is agitated in a plasticized state by the rotation of the rod-shaped jig, enters into the recess of the tip surface of the rod-shaped jig and further The metal that has entered the place is in a state where it is blocked by the side wall of the recess that extends in the circumferential direction of the rod-shaped jig, and leaks outward from the outer peripheral edge of the tip surface of the rod-shaped jig. Can be advantageously prevented.

Therefore, in the method of the present invention, the friction stir welding operation is started by inserting the tip end of the rod-shaped jig to be rotated into the edge of the abutting portion of the aluminum material to be welded on the welding start side. , After the rod-shaped jig tip portion is relatively moved with respect to the abutting portion, the rod-shaped jig tip portion may be pulled out from the abutting portion at the joining end side edge of the abutting portion, It is possible to effectively prevent the metal agitated by the tip portion of the rod-shaped jig that is rotated from leaking out from the respective end faces of the joining start side and the joining end side of the aluminum materials to be joined. .

Therefore, according to the friction stir welding method according to the present invention as described above, the welding is caused by the leakage of the metal from the respective end faces of the welding start side and the welding end side of the two aluminum materials to be welded. The occurrence of defects can be very effectively prevented, and thereby the abutting portion and the weight of two aluminum materials to be joined, which have been conventionally performed to prevent the occurrence of such joining defects. After the friction stir welding operation, the post-treatment of cutting or melting welding the unwelded portion formed over the predetermined length on the joining start end side portion and the joining end end side portion of the mating portion, It can be effectively omitted.

Further, in order to solve the above-mentioned technical problem, in the present invention, one of the two aluminum materials to be joined is superposed on the other, and between the two aluminum materials. For the fillet part to be formed,
While rotating the rotary jig, inserting the tip of the rotary jig and moving the rotary jig relative to each other allows the fillet portion to be friction stir welded. Using a rod-shaped jig whose front end surface is a concave spherical surface, and the rod-shaped jig is used in the overlapping direction of the two aluminum materials so that the concave spherical surface faces the fillet portion. While rotating around the axis in a tilted state, at one of the distal end portions having a concave spherical surface, the distal end portion is inserted into the fillet portion and relatively moved, and the following formula: t ₁ + t ₂ -2r -Sin θ <1 r ≦ 20, θ ≦ 30 [where t ₁ and t ₂ are the thicknesses or diameters (mm) of the two aluminum materials to be joined, r: the radius of the rod-shaped jig (mm) ), Θ: Two aluminum The friction stir welding method is characterized in that the friction stir welding operation is performed under the condition that the inclination angle (°) of the rod-shaped jig with respect to the material superposition direction is satisfied. is there.

That is, in the friction stir welding method according to the present invention, the tip surface of the rod-shaped jig inserted into the fillet portions of the two aluminum materials to be welded is a concave spherical surface. The contact area of the tip end surface of the rod-shaped jig with the aluminum material is increased, and no pin is provided on the tip end surface. Therefore, at the joint portion formed along the fillet portion, It is possible to advantageously eliminate the formation of the protrusions formed by the withdrawal traces, and, despite the fact that no pin is provided, the tip of the rod-shaped jig is rotated as the rod-shaped jig rotates. The area around the fillet portion that has been plasticized by the contact with can be sufficiently agitated, and the two aluminum materials can be reliably joined without melting.

Further, in such a method of the present invention,
By making the tip end surface of the rod-shaped jig a concave spherical surface, a side wall extending in the circumferential direction is formed at the outer peripheral edge portion of the tip end surface of the rod-shaped jig. The metal around the fillet part that was plasticized by the contact is in a state where it is blocked by the side wall,
Leakage from the outer peripheral edge of the rod-shaped jig tip surface to the outside can be advantageously prevented, and the metal from the end faces of the joining start side and the joining end side of the aluminum materials to be joined can be prevented. Leakage can also be effectively prevented, and as a result, the occurrence of joint defects due to such metal leakage can be prevented.

Moreover, the friction stir welding method according to the present invention is also one in which the friction stir welding operation is performed under the condition that all of the above three expressions are satisfied. Despite the fact that the tip provided on the butt portion of the rod-shaped jig having a diameter larger than that of the pin provided on the above is inserted into the butt portion, the friction stir welding operation can be performed smoothly, and Good joints can be formed along the overlap.

Therefore, according to the friction stir welding method according to the present invention as described above, two aluminum materials to be superposed on each other are formed with a protrusion formed by a pull-out trace of the pin of the rotary jig at the joint portion. In addition, it is possible to securely and smoothly join while preventing joining defects caused by metal leakage, and as a result, work to remove such protrusions after the friction stir welding operation is completed or unjoined. Post-treatment for parts can be advantageously omitted,
The workability of friction stir welding of aluminum materials can be enhanced more effectively.

In the friction stir welding method according to the present invention, when a rod-shaped jig whose one axial end surface is a concave spherical surface is used as a rotating jig, it is preferable that the concave spherical surface be It has a radius of 15 mm or more. As a result, the agitating action of the tip of the rod-shaped jig on the plasticized parts (peripheral parts of the fillet) of the two aluminum materials that have been plasticized by contacting the tip of the rod-shaped jig that is rotated Can be advantageously increased, so that even better joining quality can be effectively ensured at the joining portion of two aluminum materials.

[0030]

BEST MODE FOR CARRYING OUT THE INVENTION The aluminum material used in the friction stir welding method according to the present invention as described above is an expanded material having a plate shape, a rod shape, or a pipe shape, which is made of normal aluminum or aluminum alloy. Material, casting material, extruded material, etc. are all targeted,
From these, it will be appropriately selected and used according to the purpose. The material of such an aluminum material is not particularly limited, and may be appropriately determined according to the intended use of the product to be finally obtained, the required quality, and the like.

Then, using two such plate materials made of aluminum, in a state where they are butted against each other,
When performing friction stir welding at the butt portion, for example, as shown in FIG. 1, first, the two aluminum plate members 10 and 12 are contacted with each other at their end surfaces.
Butt and position. At this time, the two aluminum plate members 10 and 12 are preferably detachable by a suitable restraint jig (not shown) so that the abutting portions 14 of the two aluminum plate members 10 and 12 are not separated from each other. , Irremovably restrained.

Next, the two aluminum plate materials 10, 1
The friction stir welding operation with respect to the butt portion 14 of No. 2 is carried out by using a rotating jig, and here, as such a rotating jig, as shown in FIG. Tool 16 will be used. In this rod-shaped jig 16, in particular, the tip surface 17 on one side in the axial direction is a circular flat surface, and the outer peripheral portion of the tip surface 17 has a relatively shallow depth. A circular circumferential groove 18 is provided so as to be positioned concentrically. By this, the rod-shaped jig 1
In Fig. 6, a side wall 20 formed of an outer side wall portion of the circular circumferential groove 18 and extending continuously in the circumferential direction is formed on the outer peripheral edge portion of the one end surface 17 in the axial direction, and the tip thereof is formed. The surface 17 is provided with no pin like that provided in a rotary jig used in a conventional friction stir welding operation,
It is configured.

The depth of the circumferential groove 18 of the rod-shaped jig 16 is not particularly limited, but is preferably 2 mm or less. Because here, the circumferential groove 18
Is provided, the tip surface 17 of the rod-shaped jig 16 is provided.
In addition to increasing the contact area of the abutting portion 14 with respect to the peripheral portion, the tip surface 17 is roughened, so that, as will be described later, during the friction stir welding operation of the abutting portion 14 of the two aluminum plate members 10 and 12, The tip of the rod-shaped jig 16 rotated at a high speed is attached to the abutting portion 14
When it is inserted into the socket and moved relatively, the abutting portion 14
The peripheral portion of the rod-shaped jig 16 can be surely agitated by the tip-shaped surface of the tip portion of the rod-shaped jig 16, and such a circumferential groove 18 has a depth exceeding 2 mm. Two aluminum plates 10,
This is because it adversely affects the stirring action on the peripheral portion of the butt portion 12 of 12.

Further, the lower limit of the depth of the circumferential groove 18 is not limited at all. However, in the circumferential groove 18, when the peripheral portion of the butted portion 14 in the plasticized state is stirred as the rod-shaped jig 16 rotates, the metal at the peripheral portion of the butted portion 14 becomes In order to prevent leakage from the outer peripheral edge of the tip surface 17, the outer wall of the circumferential groove 18 is formed as a side wall 20 continuously extending in the circumferential direction. If the circumferential groove 18 is too shallow, the side wall 20 constituted by the outer side wall of the circumferential groove 18 becomes too low, and when the peripheral portion of the abutting portion 14 is stirred, the metal of the peripheral portion is changed to the rod-shaped jig 16.
Since the function of preventing leakage from the outer peripheral edge portion of the front end surface 17 of the is significantly impaired, the lower limit of the depth of the circumferential groove 18 is determined to the extent that such a function can be secured. Is done.

Further, in the cylindrical rod-shaped jig 16 used here, its radius: r must be 15 mm or less. Because the radius is 15mm
The rod-shaped jig 16 that exceeds the thickness of the rod-shaped jig 16 becomes excessively large, so that the two aluminum plate materials 1 are
This is because it becomes extremely difficult to insert it into the 0, 12 butt portion 14, and it becomes difficult or impossible to carry out a smooth friction stir welding operation.

Then, as shown in FIG. 3, the rod-shaped jig 16 having such a structure is provided with two aluminum plate members 10 and 12 at the center of the tip surface 17 on the side where the circumferential groove 18 is formed. Corresponding to the joining start end of the butt portion 14 and the relative movement direction (the arrow direction in FIG. 3) with respect to the butt portion 14, in other words, the butt portion 14
3 is rotated at a high speed in a posture in which the rod-shaped jig 16 is tilted rearward with respect to the joining direction, and the tip portion of the rod-shaped jig 16 is moved to the abutting portion under such a high-speed rotation, as indicated by a two-dot chain line in FIG. Plug it in 14.

As a result, frictional heat is generated between the tip of the rod-shaped jig 16 which is rotated at a high speed and the joining start end of the abutting portion 14, and the frictional heat generates a joining start end of the abutting portion 14. While the peripheral portion of the joining start end of the butt portion 14 is agitated by further rotating the rod-shaped jig 16 at a high speed,
These structures are intermingled with each other, so that the joining start ends of the butted portions 14 are not melted and joined together. Further, here, the peripheral groove 1 in which the outer wall portion is a side wall 20 continuously extending in the circumferential direction is formed on the tip surface 17 of the rod-shaped jig 16.
8 is provided, the tip end portion of the rod-shaped jig 16 is inserted into the joining start end of the abutting portion 14, and when the peripheral portion of the joining start end is agitated, the joining start end is in a plasticized state. The metal in the peripheral portion enters the circumferential groove 18 and is further blocked by the side wall 20,
Thus, it is possible to prevent the rod-shaped jig 16 from leaking outward from the outer peripheral edge portion of the tip end surface 17 and leaking laterally from the end surface of the joining start end of the abutting portion 14. Is there.

Thus, when the tip of the rod-shaped jig 16 is inserted into the joining start end of the butting portion 14, the rearward tilt angle θ of the rod-like jig 16 with respect to the joining direction of the butting portion 14 is 5 ° or less. Because in this process,
By inserting the rod-shaped jig 16 into the abutting portion 14 at the tip end portion in a state where the rod-shaped jig 16 is tilted rearward, the tip end portion of the rod-shaped jig 16 is inserted into the abutting portion 14.
However, if the rearward inclination angle θ of the rod-shaped jig 16 with respect to the joining direction of the abutting portion 14 is larger than 5 °, the rod-shaped jig 16 will not move. This is because the resistance applied to the distal end surface 17 becomes too large during the relative movement, which hinders the smooth relative movement of the rod-shaped jig 16, and thus the smooth progress of the friction stir welding operation.

Further, in this embodiment, unlike the conventional method in which the pin provided at the center of the tip of the rotary jig is inserted into the abutting portion 14 to perform the friction stir welding operation, a rod having a diameter larger than that of the pin is used. -Shaped jig 16 Tip part 14
Since the friction stir welding operation is performed by inserting the rod-shaped jig 16 into the butt portion 14,
If the insertion depth into the
Insufficient agitation of the peripheral parts of the can be performed. Therefore, here, in order to obtain a good joint while sufficiently agitating the abutting portion 14 and smoothly advancing the friction stir welding operation, the plate thickness of the two aluminum plate members 10 and 12 (see FIG.
Mean value of (dimensions indicated by t ₁ and t ₂ ): (t ₁
The value obtained by subtracting + t ₂ ) / 2 from the insertion depth of the tip of the rod-shaped jig 16 into the abutting portion 14: r · sin θ (dimension indicated by m in FIG. 3) is less than 1 mm. It is necessary to insert the tip of the rod-shaped jig 16 into the abutting portion 14 with a sufficient depth. That is, here, the tip end portion of the rod-shaped jig 16 is inserted into the abutting portion 14 of the two aluminum plate members 10 and 12 under the condition that the following expression: (t ₁ + t ₂ ) / 2−r · sin θ <1 is satisfied. Meanwhile, the friction stir welding operation must be performed.

Then, while the rod-shaped jig 16 inserted into the joining start end of the abutting portion 14 in the above-described state is rotated at a high speed, the joining is completed along the abutting portion 14 on the side opposite to the joining starting end. Move towards the edge. After that, when the center of the tip surface 17 of the rod-shaped jig 16 reaches a position corresponding to the joining end of the abutting portion 14, the tip portion of the rod-shaped jig 16 is pulled out from the abutting portion 14 at that time.

Thus, while the rod-shaped jig 16 is relatively moved along the abutting portions 14 of the two aluminum plate members 10 and 12, while being inserted into the abutting portions 14, the rod-shaped jig is rotated at a high speed. Friction heat is generated between the tip end of the tool 16 and the abutting portion 14, and the friction heat makes the peripheral portion of the abutting portion 14 plastically workable. By the stirring action by the high-speed rotation, the tissues of the peripheral portion of the butted portion 14 do not intermingle and are not melted, and the two aluminum materials 10 and 12 are joined along the butted portion 14 from the joining start end. By forming a joint portion continuously extending over the entire length of the joining end end, the two aluminum materials 10,
The 12 are integrally joined.

In this process, the tip of the rod-shaped jig 16 inserted into the abutting portion 14 and relatively moved is located at the center of the tip surface 17 at the joining end of the abutting portion 14. At this point in time, since it is pulled out from the abutting portion 14, the joining end end is surely joined and a plasticized state is obtained as in the case of inserting the rod-shaped jig 16 into the joining start end of the abutting portion 14. The metal in the vicinity of the welded end that has entered enters the circumferential groove 18 of the tip surface 17,
Further, the side wall 20 is brought into a state in which it is blocked, whereby it leaks outward from the outer peripheral edge portion of the tip end surface 17 of the rod-shaped jig 16 and laterally from the end surface of the joining end end of the abutting portion 14. Things that leak out are also blocked.

Further, here, as described above, since the tip end surface 17 of the rod-shaped jig 16 is formed into a flat shape, and there is no pin provided in the conventional rotary jig, there is no pin. When the rod-shaped jig 16 is pulled out from the joining end end of the abutting portion 14, any protrusion formed by the pulling-out trace of the pin may be formed on the joining portion formed at the joining end end of the abutting portion 14. There is no.

Thus, in this embodiment, the tip surface 17
By rotating the rod-shaped jig 16 provided with the circumferential groove 18 in the abutting portion 14 of the two aluminum plate members 10 and 12 at a high speed while inserting the rod-shaped jig 16 at the tip portion thereof and relatively moving them. Since the peripheral portion of the butted portion 14 in the plasticized state can be sufficiently agitated by such a tip surface 17 with a large agitating force, the tip surface 17 of the rod-shaped jig 16 is The two aluminum plate members 10 and 12 can be reliably joined at the abutting portion 14, although no pin is provided on the rotating jig.

Further, in the present embodiment, since no pin is provided on the tip surface 17 of the rod-shaped jig 16, the pin formed on the joining end of the abutting portion 14 is not removed from the trace of pulling out the pin. Since no protrusions are formed, it is possible to eliminate the need to perform work to remove such protrusions after the friction stir welding operation is completed, whereby two aluminum sheet materials are Workability during friction stir welding of 10 and 12 can be effectively enhanced.

Further, in the present embodiment, both the joining start end and the joining end end of the abutting portion 14 can be surely joined together, so that they are formed at the joining start end and the joining end end. It is possible to effectively eliminate the need for post-processing such as cutting unmelted portions or performing melt welding, and workability at the time of friction stir welding of the two aluminum plate members 10 and 12 is further enhanced. Can be done.

Furthermore, in this embodiment, the value obtained by subtracting the insertion depth of the tip of the rod-shaped jig 16 into the abutting portion 14 from the average plate thickness of the two aluminum plate members 10 and 12 is less than 1 mm. Since the tip portion of the rod-shaped jig 16 is inserted into the abutting portion 14 with a sufficient depth, the friction stir welding operation can be advanced. Therefore, the rod-shaped jig can be rotated at a high speed. The friction stir welding operation can be smoothly carried out while further sufficiently stirring the peripheral portion of the butt portion 14 by the tip end portion of 16, and thus a good joining portion is formed, and two aluminum plate materials are formed. The 10 and 12 can be joined with a better joining quality.

Next, a description will be given of a method of using two plate materials made of aluminum and performing friction stir welding at the overlapping portion in a state where they are overlapped with each other.

That is, when superposing and joining the two aluminum plate members 10 and 12 by the friction stir welding method, first, as shown in FIG. 4, for example, two aluminum plate members 10 and 12 having different thicknesses are first prepared. Among them, the thick aluminum plate material 12 is placed on the upper surface of the thin aluminum plate material 10 so as to be stacked. At this time, these two aluminum plate materials 1
The two aluminum plate members 10, 12 are preferably provided by a suitable restraint jig (not shown) so that the position 0, 12 is not displaced and the overlapping portion 22 is not changed.
However, it is restrained in a detachable state.

Next, the two aluminum plate materials 10, 1
The friction stir welding operation for the superposed section 22 of No. 2 is carried out by using a rotary jig. Here, as the rotary jig, two aluminum plate materials 10 and 12 are butt welded by friction stir welding operation. The rod-shaped jig 16 used at that time, that is, as shown in FIG. 2, has a cylindrical shape as a whole, and has a tip surface 17 on one side in the axial direction.
Is a circular flat surface, and a circular peripheral groove 18 is concentrically provided on the outer peripheral portion of the tip surface 17 as a side wall 20 whose outer wall portion extends in the circumferential direction. What is used is.

Even in the cylindrical rod-shaped jig 16 used here, the radius r must be 15 mm or less. This is because the rod-shaped jig 16 having a radius of more than 15 mm has an excessively large thickness, and penetrates the upper aluminum plate 12 and is inserted into the overlapping portion 22 even under high speed rotation. Is extremely difficult, and it becomes difficult or impossible to carry out a smooth friction stir welding operation.

Then, as shown in FIG. 5, the rod-shaped jig 16 having such a structure is superposed on the upper surface of the aluminum plate member 10 at the center of the tip surface 17 on the side where the circumferential groove 18 is formed. Of the plurality of edge portions of the aluminum plate member 12 arranged in a fixed manner, the edge portion corresponding to the joining start end of the overlapping portion 22 to be joined is made to correspond to the relative edge portion. Direction (indicated by the arrow in FIG. 5), in other words, rotated at a high speed in a posture tilted backward with respect to the joining direction of the overlapping portion 22, and further, under such a high speed rotation, two points are shown in FIG. As indicated by the chain line, the tip end portion of the rod-shaped jig 16 is inserted into the overlapping portion 22 such that at least a part thereof penetrates the aluminum plate material 12. As a result, the superposition portion 22 is joined without melting the joining start end. At this time, the peripheral groove 1 is formed on the tip surface 17 of the rod-shaped jig 16.
8 and the side wall 20 extending in the circumferential direction are formed,
Similar to the first embodiment, such a joining start end peripheral portion is sufficiently agitated and reliably joined, and from the end face of the joining start end, a joining start end peripheral portion in a plasticized state is formed. It prevents the metal from leaking out.

Also here, when the tip portion of the rod-shaped jig 16 is inserted into the joining start end of the overlapping portion 22, the rearward inclination angle of the rod-like jig 16 with respect to the joining direction of the overlapping portion 22: θ. Is 5 ° or less. Such backward tilt angle: θ is 5
If it is larger than 0, the smooth relative movement of the rod-shaped jig 16 with respect to the overlapping portion 22 and the smooth progress of the friction stir welding operation are hindered, as in the above embodiment.

Also in this embodiment, the tip portion of the rod-shaped jig 16 having a diameter larger than that of the pin provided in the conventional rotary jig is inserted into the superposed portion 22 of the two aluminum plate members 10 and 12. Since the friction stir welding operation is performed, if the insertion depth of the tip end portion of the rod-shaped jig 16 into the overlap portion 22 is shallow, stirring of the peripheral portion of the overlap portion 22 by the tip portion is sufficient. Can not be done to. Therefore, here, the two superposed aluminum plate members 10, in order to sufficiently stir the superposed portion 22 and smoothly proceed the friction stir welding operation and obtain a good joint portion,
The plate thickness of the aluminum plate 12 which is located on the upper side and penetrates a part of the tip of the rod-shaped jig 16 (see FIG.
(The dimension indicated by t _{1 in} FIG. 5), the insertion depth of the tip of the rod-shaped jig 16 into the two aluminum plate members 10 and 12 is r · sin θ (the dimension indicated by m in FIG. 5).
It is necessary to insert the tip end portion of the rod-shaped jig 16 into the overlapping portion 22 with a sufficient depth so that the value obtained by subtracting is less than 1 mm. That is, here, the tip end portion of the rod-shaped jig 16 is penetrated through the aluminum plate member 12 located on the upper side and is inserted into the overlapping portion 22 under the condition that the following expression: t ₁ −r · sin θ <1 is satisfied. The friction stir welding operation must be performed.

Then, while the rod-shaped jig 16 inserted into the joining start end of the overlapping portion 22 in the above-described state is rotated at a high speed, the rod jig 16 is moved along the overlapping portion 22 to the side opposite to the joining starting end. Move toward the end of joining. After that, when the center of the tip surface 17 of the rod-shaped jig 16 reaches the position corresponding to the joining end of the overlapping portion 22 by such movement, the tip portion of the rod-shaped jig 16 is moved to the position at that time. It is pulled out from the mating portion 22 and the aluminum plate member 12 located on the upper side.

In this way, the rod-shaped jig 16 is continuously provided between the two aluminum plate members 10 and 12 superposed on each other along the overlapping portion 22 over the entire length from the joining start end to the joining end end. By forming a joint portion extending in the vertical direction, the two aluminum plate members 10 and 12 are integrally joined.

Incidentally, in such friction stir welding operation,
When superposing and joining the two aluminum plate members 10 and 12, the joining depth of the two aluminum plate members 10 and 12, in other words, the thickness of the joint portion formed along the superposed portion 22 is Of the two aluminum plate members 10 and 12, the aluminum plate member 12 positioned on the upper side preferably has a dimension of 105% or more with respect to the plate thickness t ₁ . Thereby, sufficient bonding strength can be obtained.

Further, in this embodiment, when the tip end portion of the rod-shaped jig 16 is positioned at the joining end end of the overlapping portion 22, it is pulled out therefrom, so that the overlapping portion does not overlap. The joining end of the portion 22 is securely joined, and the metal around the joining end in the plasticized state leaks outward from the outer peripheral edge of the tip surface 17 of the rod-shaped jig 16, It is prevented that the overlapping portion 22 leaks laterally from the end surface of the joining end end.

Further, here, since the tip end surface 17 of the rod-shaped jig 16 is formed into a flat shape and no pins are provided therein as in the conventional rotary jig, the rod-shaped jig 16 is not provided. When 16 is pulled out from the joining end of the overlapped portion 22, no protrusion formed by the pulling trace of the pin is formed anywhere.

As described above, according to the present embodiment, by using the rod-shaped jig 16 in which only the circumferential groove 18 is simply provided on the distal end surface 17 which is a circular flat surface, the pin is fixed to the joint portion. The two aluminum plate members 10 and 12 can be formed without forming any protrusions or unbonded parts formed by drawing marks.
It is possible to reliably join the superposed portion 14 in the superposed portion 14, and as a result, superposed joining to the two aluminum plate members 10 and 12 capable of ensuring high joining quality is excellent. With workability, it can be carried out extremely advantageously.

Further, in the present embodiment, the plate thickness of the aluminum plate member 12 which is located on the upper side of the two aluminum plate members 10 and 12 to be superposed and through which at least a part of the tip of the rod-shaped jig 16 penetrates. From the rod-shaped jig 1
The value obtained by subtracting the insertion depth that penetrates the aluminum plate material 12 into the overlapping portion 22 at the tip portion of 6 is less than 1 mm, and the tip portion of the rod-shaped jig 16 has a sufficient depth with respect to the overlapping portion 22. Since the friction stir welding operation is performed while being inserted, the two aluminum plate members 10 and 12 can be joined with superior joining quality.

Next, a method of friction stir welding at the fillet portions of two plate materials made of aluminum, which are superposed on each other, will be described.

That is, when performing lap fillet joining of the two aluminum plate materials 10 and 12 by this friction stir welding method, first, as shown in FIG. Of the two aluminum plate members 10 and 12, one aluminum plate member 10 is stacked on the upper surface of the other aluminum plate member 10 while the other aluminum plate member 12 is placed. At this time, it is preferable that the two aluminum plate members 10 and 12 are not displaced from each other and the position of the fillet portion 24 is changed, so that the two aluminum plates 10 and 12 are not displaced from each other by an appropriate restraining jig (not shown). Plate material 10,
12 is releasably restrained.

Next, the two aluminum plate materials 10, 1
The friction stir welding operation on the fillet 24 of No. 2 is performed by using a rotating jig. Here, as shown in FIG. 6, the rotating jig has a columnar shape as a whole, A rod-shaped jig 28 having a concave spherical surface 26 on its one end surface in the axial direction is used. As a result, in the rod-shaped jig 28, the side wall 30 that gives the outer peripheral edge portion of the concave spherical surface 26 is formed on one end surface in the axial direction so as to extend continuously in the circumferential direction. The concave spherical surface 26 formed of the one end surface in the axial direction is configured without any pin provided in a rotary jig used in the conventional friction stir welding operation.

The radius R of the concave spherical surface 26 in the rod-shaped jig 28 is not particularly limited, but is preferably 15 mm or more. This is because, here, the one end surface of the rod-shaped jig 28 in the axial direction is formed as the concave spherical surface 26 to increase the contact area of the concave spherical surface 26 formed of the distal surface with the peripheral portion of the fillet portion 24. During the friction stir welding operation on the fillet portions 24 of the two aluminum plate members 10 and 12, the tip end portion of the rod-shaped jig 28 rotated at a high speed is attached to the fillet portions 24.
When it is inserted into the groove and moved relatively, the peripheral portion of the fillet portion 24 has a concave spherical surface 26 at the tip of the rod-shaped jig 28.
It is ensured that the concave spherical surface 26 has a radius of less than 15 mm: R
In the case of the form having the above, the depth of the concave spherical surface 26 becomes too deep, which adversely affects the stirring action on the peripheral portions of the fillet portions 24 of the two aluminum plate members 10 and 12. Is. Also, this concave spherical surface 2
The upper limit of the radius of 6 is not limited in any way, and may be appropriately determined as long as the effect of increasing the contact area of the fillet portion 24 with the peripheral portion due to the concave spherical shape is not impaired. is there.

Further, in the cylindrical rod-shaped jig 28 used here, its radius: r must be 20 mm or less. Because the radius is 20mm
The rod-shaped jig 28 that exceeds the above-mentioned size has an excessively large thickness, and it is extremely difficult to insert the rod-shaped jig 28 into the fillet portion 24 even under high-speed rotation, which makes it difficult to perform a smooth friction stir welding operation. Is impossible.

Then, as shown in FIG. 7, the rod-shaped jig 28 having such a structure is provided at the center of the concave spherical surface 26 and at the corners of the two aluminum plate members 10 and 12 which are arranged to overlap each other. In a posture corresponding to the joining start end of the flesh portion 24 and inclined with respect to the overlapping direction of the two aluminum plate members 10 and 12 so that the concave spherical surface 26 faces the fillet portion 24. , Rotate at high speed, and further under such high speed rotation,
As shown by the chain double-dashed line in FIG. 7, the tip of the rod-shaped jig 28 is inserted into the fillet 24. As a result, the fillet portion 24 is joined without melting the joining start end. Further, at this time, since the tip end surface of the rod-shaped jig 28 is the concave spherical surface 26 and the side wall 30 extending in the circumferential direction is formed on the tip end surface, similar to the first and second embodiments. , The portion around the welding start end is sufficiently agitated to ensure reliable welding, and it is possible to prevent the metal around the welding start end periphery from leaking from the end face of the welding start end. Will be done.

Thus, when inserting the tip of the rod-shaped jig 28 into the joining start end of the fillet portion 24, the inclination angle of the rod-shaped jig 28 with respect to the superposing direction of the two aluminum plate members 10 and 12. : Α is set to 30 ° or less.
This is because in this step, the rod-shaped jig 28 is tilted, and the tip portion of the rod-shaped jig 28 is inserted into the fillet portion 24 so that the tip portion of the rod-shaped jig 28 is positioned on the lower side. Area around the fillet 24 on the plate 10 side and fillet 2 of the aluminum plate 12 located on the upper side
It is designed to stir the peripheral portion of the aluminum plate 4 evenly. However, when the inclination angle exceeds 30 °, the fillet portion 2 on the side of the aluminum plate 10 located on the lower side.
This is because the peripheral portion of No. 4 has a larger stirring action than the peripheral portion of the fillet portion 24 of the aluminum plate member 12 located on the upper side, which may cause a defective joint.

Further, as in the first and second embodiments, the rod-shaped jig 28 is tilted backward with respect to the joining direction of the fillet portions 24, and the fillet portions are formed at the tip portions thereof. Two
You may make it insert in 4. Thereby, the friction stir welding operation can be performed more smoothly.

Further, also in this embodiment, the rod-shaped jig 28 having a diameter larger than that of the pin provided in the conventional rotary jig.
The tip portion of the rod-shaped jig 28 is inserted into the fillet portions 24 of the two aluminum plate members 10 and 12 to perform the friction stir welding operation.
If the depth of insertion into 4 is shallow, the fillet portion 24 by the tip end portion
Insufficient agitation of the peripheral parts of the can be performed. Therefore, here, in order to obtain a good joint while sufficiently stirring the fillet portion 24 and smoothly performing the friction stir welding operation, the plate thicknesses of the two aluminum plate members 10 and 12 (in FIG. 7). total value of dimensions indicated by t ₁ and t ₂ : t ₁ + t ₂
To twice the depth of insertion of the tip of the rod-shaped jig 28 into the two aluminum plate members 10 and 12: 2r · si
The rod-shaped jig 28 is adjusted so that the value obtained by subtracting nα (double the value indicated by m in FIG. 7) is less than 1 mm.
Therefore, it is necessary to insert the tip of the into the fillet portion 24 with a sufficient depth. That is, here, the friction stir welding operation must be performed while inserting the tip end portion of the rod-shaped jig 28 into the fillet portion 24 under the condition that the following expression: t ₁ + t ₂ −2r · sin α <1 is satisfied. Of.

Then, while the rod-shaped jig 28 inserted into the joining start end of the fillet portion 24 in the above-described state is rotated at high speed, the rod jig 28 is moved along the fillet portion 24 to the side opposite to the joining start end. Towards the end of joining (the direction perpendicular to the paper surface in Fig. 7)
To move. After that, when the center of the concave spherical surface 26 of the rod-shaped jig 28 reaches the position corresponding to the joining end end of the fillet portion 24 by such movement, the tip of the rod-shaped jig 28 is moved to the corner at that time. Pull out from the meat portion 24.

In this way, the rod-shaped jig 28 is continuously provided between the two aluminum plate members 10 and 12 superposed on each other along the fillet portion 24 over the entire length from the joining start end to the joining end end. By forming a joint portion extending in the vertical direction, the two aluminum plate members 10 and 12 are integrally joined.

By the friction stir welding operation as described above,
When the two aluminum plate members 10 and 12 are overlapped and fillet-bonded, the joining depth of the two aluminum plate members 10 and 12, in other words, the thickness of the joint portion formed along the fillet portion 24 is Of the two aluminum plate members 10 and 12, it is desirable that the aluminum plate member 12 positioned on the upper side has a thickness of 105% or more with respect to the plate thickness t ₁ . Thereby, sufficient bonding strength can be obtained.

Further, here, since the tip end portion of the rod-shaped jig 28 is pulled out from the joining end end of the fillet portion 24, the tip end portion of the rod-shaped jig 28 is pulled out therefrom. The joining end is securely joined, and the metal in the vicinity of the joining end, which is in a plasticized state, leaks outward from the outer peripheral edge of the concave spherical surface 26 of the rod-shaped jig 28 to form a fillet portion. It is possible to prevent the side surface of the joining end end of 24 from leaking laterally.

Further, in the present embodiment, the fillet portion 2
Since the tip end surface of the rod-shaped jig 28 to be inserted into the connector 4 is a concave spherical surface 26 and no pin is provided in the conventional rotary jig, the rod-shaped jig 28 is joined to the fillet portion 24. When the pin is pulled out from the end end, no projection formed by the trace of pulling out the pin is formed at the joint portion formed at the joint end end of the fillet portion 24.

As described above, according to the present embodiment, by using the rod-shaped jig 28 having the concave spherical surface 26 at the tip end surface, no protrusion or unbonded portion formed by a pin withdrawal mark is formed at the joint portion. It is possible to reliably join the two aluminum plate members 10 and 12 that are overlapped with each other at the fillet portion 24 without forming them, and as a result, it is possible to secure a high degree of joining quality. That is, the superposition and joining of the two aluminum plate members 10 and 12 can be performed extremely advantageously with excellent workability.

Further, in the present embodiment, a value obtained by subtracting twice the size of the insertion depth of the rod-shaped jig 28 into the fillet portion 24 from the total plate thickness of the two aluminum plate members 10 and 12. Is less than 1 mm so that the friction stir welding operation can proceed while the tip of the rod-shaped jig 28 is inserted into the fillet 24 with a sufficient depth. Therefore, the plate materials 10 and 12 can be joined with a better joining quality.

By the way, in the above three embodiments, the two aluminum plate materials 10 and 12 were used as the aluminum materials to be friction stir welded.
Using an aluminum material exhibiting a rod-shaped form or a pipe-shaped form, in a state where they are butted against each other, or in a state where they are put on each other, by the friction stir welding method according to the present invention, a butt portion, a superposed portion, a fillet portion, Of course, friction stir welding can be performed.

In the first and second embodiments,
Although the recess was formed in the circumferential groove 18 provided on the tip surface 17 of the rod-shaped jig 16, the shape, the disposition form, and the disposition number of this recess are not limited to this. Not. Therefore, for example, as shown in FIG.
A plurality of circumferential grooves 32 having different diameters are provided on the tip end surface 17 of the rod-shaped jig 16 in a state of being concentrically located at a predetermined distance in the radial direction.
It is also possible to form a recess by each one of them, and as shown in FIG. 9, a plurality of linear grooves 34 that extend straight in the radial direction are formed from the center of the tip surface 17 to the outer periphery. Formed so as to extend radially toward the respective portions, and each of the grooves 3 thereof is formed.
It is also possible to make 4 a recess. Further, as shown in FIG. 10, a plurality of grooves 36 extending while drawing an arcuate locus are formed so as to extend radially from the center of the tip surface 17 toward the outer peripheral portion, and each groove 36 is recessed. Or as shown in FIGS. 11 and 12,
Holes 3 which are independent of each other on the whole or a part of the tip surface
A large number or a plurality of 8 are provided in a regularly arranged state or in an irregularly arranged state, and their hole portions 38 are provided.
Even if each of them is made into a recess, there is no problem.

[0080]

EXAMPLES Some examples of the present invention will be shown below to clarify the present invention in more detail. However, the present invention is not limited by the description of such examples. Needless to say, it is not something to receive. Further, the present invention, in addition to the following examples, further, in addition to the embodiments of the invention described above, based on the knowledge of those skilled in the art, without departing from the spirit of the present invention,
It should be understood that various changes, modifications, improvements and the like can be made.

<Example 1> First, thickness: 1.2 mm,
6000: a rectangle with a width of 700 mm and a length of 1200 mm
System aluminum alloy plate material, thickness: 0.8 mm, width: 7
One piece of each rectangular 6000 series aluminum alloy plate material having a length of 00 mm and a length of 1200 mm is prepared as a test material, while a rotating jig is made of a steel round bar having a diameter of 16 mm and is provided on one side in the axial direction. The tip surface is a circular flat surface, and the tip surface has a diameter of 15 mm and a depth of 0.
A rod-shaped jig provided with a 6 mm circumferential groove was prepared.

Then, the two prepared test materials are arranged so as to abut each other at their end faces and restrained by a known restraining jig, and then the prepared rod-shaped jig is formed with a circumferential groove. At the center of the side tip surface, in the posture corresponding to the joining start end of the abutting portion of the two test materials and tilted backward at an inclination angle of 3 ° with respect to the joining direction of the abutting portion, It was brought into contact with the joining start end. Then, while rotating the rod-shaped jig at 2000 rpm at a high speed, the rod-shaped jig is inserted into the joining start end of the abutting portion at the tip portion thereof, and further, along the abutting portion toward the joining end end side, 50
The rod-shaped jig is moved at a feed rate of 0 mm / min, and when the center of the tip surface of the rod-shaped jig reaches a position corresponding to the joining end of the butted portion, the tip of the rod-shaped jig is moved from the butted portion. Pulled out. In this way, the two test materials were friction stir welded at the butt portion, and thus a joined body was obtained in which the two test materials were integrally butt welded. In the friction stir welding operation here, the value obtained by subtracting the insertion depth of the rod-shaped jig from the average plate thickness of the two test materials is about 0.58 mm, which is defined in the present invention. 1
The value is smaller than mm.

Then, using the thus obtained joint body,
When a penetrant flaw detection test was performed on the back surface of the bonded portion of the bonded body by a known method, it was confirmed that there was no color development and that the bonded portion was sound. In addition, as a result of observing the cross-sectional macrostructure of the bonded portion of such a bonded body, no crack was observed at any of the bonding start end and the bonding end end,
This also confirmed that the joint was sound. Further, as a result of performing a known three-point bending test on the joint portion of this joint body, it was possible to bend the joint portion without causing any cracks in the joint portion. Then, when a predetermined press molding is performed on such a bonded body, molding defects such as cracks do not occur at the bonded portion, and for example, it can be sufficiently used as an outer plate of an automobile,
confirmed.

Example 2 First, thickness: 1.2 mm,
6000: a rectangle with a width of 600 mm and a length of 1600 mm
System aluminum alloy plate material, thickness: 0.8 mm, width: 6
One piece of each rectangular 6000 series aluminum alloy plate having a length of 00 mm and a length of 1600 mm is prepared as a test material, while the same rod-shaped jig as that used in Example 1 is prepared as a rotating jig. did.

Next, of the two test materials prepared,
After placing a thick test material on top of a thin test material and restraining it with a known restraining jig, the prepared rod-shaped jig is attached to the circumferential groove forming side. At the center of the tip surface, of the four edge parts of the specimen located above,
3 corresponding to the edge of the overlapped portion to be joined, which corresponds to the edge of the overlapped portion and the joining direction of the overlapped portion.
The edge portion was brought into contact with the edge portion in a rearwardly inclined posture. After that, while rotating the rod-shaped jig at a high speed at 2000 rpm, the test material located on the upper side is penetrated at the tip portion thereof and inserted into the overlapped portion, and further along the overlapped portion, the joining end end is inserted. When the center of the tip surface of the rod-shaped jig reaches a position corresponding to the joining end of the overlapping portion, the rod-shaped jig is moved toward the side at a feed rate of 500 mm / min. The tip part was pulled out from the overlapped part and the sample material located on the upper side. As a result, the two test materials were friction stir welded in the superposition section, and
A joined body was obtained by integrally superposing and joining the test materials. In the friction stir welding operation here, the value obtained by subtracting the insertion depth of the rod-shaped jig from the plate thickness of the upper one of the two test materials to be stacked is about 0. 0.78 mm, 1 as specified in the present invention
The value is smaller than mm.

Then, using the bonded body thus obtained,
In the same manner as in Example 1, as a result of performing a penetrant inspection on the backside of the joint of the joined body and observing the cross-sectional macrostructure of the joint, there was no color development, and the joining start end and joining end No cracks were observed in any of the above, which confirmed that the joint was sound.
In addition, as a result of performing a known three-point bending test on the bonded portion of the bonded body in the same manner as in Example 1, it was possible to bend without causing any cracks in the bonded portion. Then, when a predetermined press molding is performed on such a bonded body, molding defects such as cracks do not occur in the bonded portion, and for example, it can be sufficiently used for an inner panel of an automobile, confirmed.

<Third Embodiment> First, thickness: 1.2 mm,
6000: a rectangle with a width of 600 mm and a length of 1600 mm
System aluminum alloy plate material, thickness: 0.8 mm, width: 6
Each of the rectangular 6000 series aluminum alloy plate materials having a length of 00 mm and a length of 1600 mm is prepared as a test material, while a rotating jig is made of a steel round bar having a diameter of 16 mm and is provided on one side in the axial direction. A rod-shaped jig having a concave spherical end surface was prepared.

Next, of the two prepared test materials,
After placing a thick test material on the upper surface of the thin test material and restraining it by a known restraining jig, the prepared rod-shaped jig is formed into a concave spherical shape. At the center of the tip surface, corresponding to the joining start end of the fillet portion in the two test materials that are overlapped with each other, and tilting backward at a tilt angle of 3 ° with respect to the joining direction of the fillet portion,
The edges of the two test materials should be tilted at an angle of 5 ° with respect to the overlapping direction of the two test materials so that the concave spherical surface faces the fillet. Contacted with. Then, while rotating the rod-shaped jig at high speed at 2000 rpm, insert the rod-shaped jig into the fillet portion at the tip end,
Further, along the fillet portion, toward the end of the joint, 50
The rod-shaped jig is moved at a feed rate of 0 mm / min, and when the center of the tip surface of the rod-shaped jig reaches a position corresponding to the joining end of the filleted portion, the tip of the rod-shaped jig is filleted. I pulled it out of the department. As a result, the two test materials were friction stir welded in the fillet portion, and thus a joined body was obtained in which the two test materials were integrally overlapped and fillet welded. In the friction stir welding operation here, the value obtained by subtracting twice the insertion depth of the rod-shaped jig from the total plate thickness of the two test materials is about 0.61 mm. The value is smaller than the prescribed value of 1 mm.

Then, using the bonded body thus obtained,
In the same manner as in Examples 1 and 2, as a result of performing a penetrant inspection on the backside of the joint portion of the joined body and observing the cross-section macrostructure of the joint portion, no color was developed and the joint start end and the joint were joined. No cracks were observed at any of the ends, confirming that the joint was sound. In addition, as a result of performing a known three-point bending test on the joined portion of the joined body in the same manner as in Examples 1 and 2,
It was able to bend without causing any cracks in the joint. Then, when a predetermined press molding is performed on such a bonded body, molding defects such as cracks do not occur in the bonded portion, and for example, it can be sufficiently used for an inner panel of an automobile, confirmed.

[0090]

As is apparent from the above description, according to the friction stir welding method according to the present invention, two aluminum materials which are butted against each other or overlap each other are provided at their joints with a pin of a rotary jig. It is possible to reliably and smoothly perform butt joining, superposition joining, or lap fillet joining without forming any protrusion formed by the pull-out trace of, and as a result, after the friction stir welding operation is completed. , Which can be advantageously released from the extra work for removing the projections formed by the pulling traces of the pins, and improves the workability during friction stir welding of aluminum materials.
This can be achieved extremely advantageously.

[Brief description of drawings]

FIG. 1 is an explanatory view showing an example of a step of butt-joining two aluminum materials by a friction stir welding operation according to the method of the present invention, showing a state where two aluminum materials to be joined are butted against each other. .

FIG. 2 is a perspective main part explanatory view showing an example of a rotary jig used when butt-joining two aluminum materials by a friction stir welding operation according to the method of the present invention.

FIG. 3 is an explanatory view showing another example of the step of butt-joining two aluminum materials by friction stir welding operation according to the method of the present invention, in which a rotary jig is inserted into the butt portion of the two aluminum materials. Is shown.

FIG. 4 is an explanatory view showing an example of a step of superposing and joining two aluminum materials by a friction stir welding operation according to the method of the present invention, showing a state in which the two aluminum materials to be joined are superposed on each other. ing.

FIG. 5 is an explanatory view showing another example of the step of superposing and joining two aluminum materials by a friction stir welding operation according to the method of the present invention, in which a superposed portion of two superposed aluminum materials is rotated. The state which inserts a jig is shown.

FIG. 6 is a longitudinal cross-sectional principal part explanatory view showing an example of a rotary jig used when lap fillet joining is performed by friction stir welding operation according to the method of the present invention.

FIG. 7 is an explanatory view showing an example of a step of laminating fillet joining by friction stir welding operation according to the method of the present invention, in which the fillet portions of the two superposed aluminum materials are subjected to rotary curing. The state which inserts a tool is shown.

FIG. 8 is an explanatory bottom view showing another example of a rotary jig used for butt joining and superposition joining of two aluminum materials by a friction stir welding operation according to the method of the present invention.

FIG. 9 is a bottom view showing still another example of a rotary jig used for butt-joining and superposing-joining two aluminum materials by a friction stir welding operation according to the method of the present invention.

FIG. 10 is a bottom view showing another example of a rotary jig used for butt joining and superposition joining of two aluminum materials by friction stir welding operation according to the method of the present invention.

FIG. 11 is a bottom view showing still another example of a rotary jig used for butt joining and superposition joining of two aluminum materials by friction stir welding operation according to the method of the present invention.

FIG. 12 is an explanatory bottom view showing another example of a rotating jig used for butt-joining and superposing-joining two aluminum materials by a friction stir welding operation according to the method of the present invention.

[Explanation of symbols]

10, 12 Aluminum plate material 14 Butt portion 16, 28 Rod jig 17 Tip surface 18, 32 Circumferential groove 20, 30
Side wall 22 Overlap portion 24 Fillet portion 26 Concave spherical surface 34, 36
Groove 38 Hole

Continued front page    (72) Inventor Koji Tanaka             Sumitomo Light Gold 5-11-3 Shimbashi, Minato-ku, Tokyo             Inside the industry F-term (reference) 4E067 AA05 BG00 CA04

Claims (6)

[Claims] 1. Abutting two aluminum materials to be joined together, and rotating the rotating jig with respect to the butting portion, inserting at the tip portion thereof and relatively moving the abutting portion so that the butting portion is rubbed. When stirring and joining, as the rotating jig, a cylindrical shape was formed, and a recess was provided on one end face in the axial direction, and a part of the end face other than the part where the recess was formed was flat. A rod-shaped jig is used, and while rotating the rod-shaped jig around the axis in a posture in which the rod-shaped jig is inclined rearward with respect to the relative movement direction with respect to the abutting portion, At the tip portion, while being inserted into the butt portion and relatively moved, the following equations: (t ₁ + t ₂ ) / 2−r · sin θ <1 r ≦ 15, θ ≦ 5 [where t ₁ , t ₂ : Two a to be joined Friction stirring under the conditions that each thickness or diameter (mm) of the minium material, r: radius of the rod-shaped jig (mm), θ: backward inclination angle (°) of the rod-shaped jig] are satisfied. A friction stir welding method characterized by performing a welding operation. 2. One of the two aluminum materials to be joined is superposed on the other, while the rotating jig is rotated with respect to the overlapped portion, and at the tip end thereof,
When one of the aluminum members is penetrated, inserted, and relatively moved, when the superposed portion is friction stir welded, the rotating jig has a cylindrical shape and one end face in the axial direction. A rod-shaped jig is provided in which a recess is provided, and a portion of the tip surface other than the portion where the recess is formed is a flat surface, and the rod-shaped jig is moved relative to the overlapping portion. While rotating about an axis in a posture inclining backward, the concave portion is inserted into the overlapping portion at one tip portion provided on the tip surface and relatively moved, and the following formula: t ₁ −r · sin θ <1 r ≦ 15, θ ≦ 5 [where t ₁ is the thickness or diameter (mm) of the two aluminum materials to be joined, which are located on the upper side in the superposed state. ), R: Rod shape Ingredients radius (mm), θ: tilt angle after the rod-shaped jig (°)] under the conditions that satisfy the friction stir welding method characterized by performing the friction stir welding operation. 3. The friction stir welding method according to claim 1, wherein the recess has a depth of 2 mm or less and is provided on one end surface of the rod-shaped jig. 4. The method according to claim 1, wherein the recess has a side wall extending in the circumferential direction of the rod-shaped jig and is provided on one end surface of the rod-shaped jig. The friction stir welding method as described in 1. 5. One of the two aluminum materials to be joined is superposed on the other, while the rotary jig is rotated with respect to the fillet portion formed between the two aluminum materials, When the fillet portions are friction stir welded by inserting at the tip portion and relatively moving, the rotation jig has a cylindrical shape, and one tip end surface in the axial direction is a concave spherical surface. Using a rod-shaped jig, the rod-shaped jig is tilted with respect to the direction in which the two aluminum materials are superposed so that the concave spherical surface faces the fillet portion. While rotating to, at the one tip part where the tip surface is a concave spherical surface,
The following formula: t ₁ + t ₂ −2r · sin θ <1 r ≦ 20, θ ≦ 30 [where t ₁ and t ₂ are two aluminums to be joined together] Each thickness or diameter (mm) of the material, r: radius of the rod-shaped jig (mm), θ: inclination angle (°) of the rod-shaped jig with respect to the overlapping direction of the two aluminum materials] The friction stir welding method is characterized in that the friction stir welding operation is performed under such conditions. 6. The friction stir welding method according to claim 5, wherein the concave spherical surface has a radius of 15 mm or more.