JP3452044B2 - Friction stir tool, joining method using the same, and method for removing fine voids on casting surface - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a friction stir tool, a joining method using the same, and a method for removing fine voids on a casting surface.

[0002]

2. Description of the Related Art It has been proposed to use friction stir welding in order to join not only metal members of the same kind but also aluminum members and other metal members having different materials. For example, a method in which a stirring pin of a high-speed rotating friction stir tool is inserted along an abutting surface where an aluminum alloy plate and a dissimilar metal plate are butted, and both plates are softened by friction heat to perform friction stir welding. Is being done.

[0003] The friction stir tool 70 is shown in FIG.
As shown in (B), the tool body 72 includes a cylindrical tool main body 72 and a stirring pin 74 that hangs from the center of the bottom surface 73 so as to be concentric with the axis of the main body 72, and along the abutting surface 77 of the metal members 76 and 78. It is operated so as to rotate at a high speed and to move about 3 ° in a direction opposite to the moving direction while being pressed along the axial direction. At the mark where the stirring tool 70 has passed, the metal member 7 frictionally stirred by the stirring pin 74 is provided.
A joint portion W including both Nos. 6 and 78 is formed.

[0004] However, when the joining tool 70 is operated in a state where the axis of the stirring pin 74 is displaced from the abutting surface 77, an unfused portion 79 is formed in the joining portion W as shown in FIG. Therefore, there has been a problem that the joining strength is greatly reduced. Further, for example, using a friction stir tool 70 having a stirring pin 74 having a diameter of 5 mm, a gap formed in the abutting surface 77 between the metal members 76 and 78 exceeds 2 mm, and the axis of the agitating pin 74 and the abutting surface 77 When the deviation amount exceeds 2 mm, the unfused portion 7
9 was also easily formed.

Further, as shown in FIG. 8 (B), since the width of the joining portion W is slightly larger than the diameter of the stirring pin 74, the friction at the time of performing the butt joining or the lap joining is increased. High accuracy is required for positioning the stirring tool 70. In order to solve the above-mentioned inconvenience, a method of sensing the abutting surface and the planned movement trajectory while increasing the diameter of the stirring pin 74 of the friction stirring tool 70 can be considered. However, if the diameter of the stirring pin 74 is increased, the
2 also needs to be increased in diameter, and the pressing force and the rotational thrust applied thereto increase, so that the equipment becomes large and the cost increases.
In addition, there is a problem that adding the sensor function further increases the cost. Alternatively, when removing fine voids on the casting surface of the aluminum alloy (including the surface layer),
Even when the friction stir tool 70 is moved along the surface while rotating, there is a problem that it is necessary to repeatedly perform many movement operations to form a zigzag movement trajectory.

[0006]

SUMMARY OF THE INVENTION The present invention solves the above-mentioned problems in the prior art, and can reliably form a high-quality joint without increasing the diameter of the tool body and the stirring pin. It is an object of the present invention to provide a friction stir tool capable of efficiently removing fine voids in the above, a joining method using the same, and a method for removing fine voids on a casting surface.

[0007]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention has been made based on the idea of enlarging the rotation trajectory of a stirring pin in a friction stir tool as a result of research conducted by the inventors. It is. That is, the first friction stir tool (Claim 1) of the present invention includes a tool main body including a circular bottom surface, and a projection protruding from the bottom surface of the tool main body and being parallel to and parallel to the axis of the tool main body. and agitating pin having an axis that is eccentric against, only including, a peripheral surface and front end surface of the stirring pin according
At least one is provided with unevenness including a screw .

According to this, the stirring pin moves with the rotation of the tool main body while forming a circular rotation trajectory larger than the diameter of the stirring pin about the axis of the main body. For this reason, the stirring pin forms a locus including continuous circular rotation and movement such as a straight line along the abutting surface or the overlapping surface of the pair of metal members, or along the casting surface. It is possible to easily form a joining portion or a fine void removing portion (stirring portion) having a wide cross section. Moreover, the peripheral surface and the tip surface of the stirring pin are reduced.
Both sides have unevenness including screws, so a stirring pin
The contact area with the metal member itself or the casting surface increases. This
For this reason, it includes continuous circular rotation and movement drawn by the stirring pin.
Depending on the locus, wide joints or fine void removal parts (turbulence
The stirrer can be more reliably formed with higher quality. Therefore, it is easy to reliably perform high-quality friction stir welding without requiring positioning accuracy of the stirring tool or to provide a sensor, or to efficiently remove fine voids on the surface of a casting including a surface layer. As the friction stir tool, a tool formed from a hard metal or alloy having a higher melting point than the target metal member or casting, such as high-speed tool steel, is used. In addition, if the tool body has a circular bottom surface, a cylindrical body and a cylindrical body including the same are, of course,
It may be a polygonal pillar such as a square pillar or a hexagonal pillar. Furthermore, the rotation speed of the stirring tool is set slightly higher than the rotation speed of the conventional stirring tool, and the rotation speed increases as the eccentric amount increases. Still further, the irregularities
Has a large number of protrusions protruding in a grid pattern on the tip surface of the stirring pin.
Form, form in which one or more ridges are projected on the tip surface,
Or provided with a plurality of rings protruding strip concentrically tip surface
Forms are included. Also, on the peripheral surface near the tip of the stirring pin
On the other hand, a large number of grooves or dents are protruded along the axial direction.
Also included are forms .

Further , the second friction stir tool of the present invention (contract
Claim 2) relates to a tool body including a circular bottom surface,
Projecting from the bottom of the tool body and parallel to the axis of the tool body
Stirring pin having an axis eccentric with respect to the axis
And the bottom surface of the tool body
A spiral ridge protruding from the edge of
Is provided . According to this,
Wide cross-section joint or fine void removal part (stirring part)
Can be easily formed and the spiral ridges can be
Since it is provided on the bottom of the body, it is suitable for the surface of metal members and castings.
The tool body in vertical position
To easily rotate and move the stirring tool
It is also possible. For this reason, the stirring pin draws continuously
The trajectory, including circular rotation and movement, allows a wide range of joints and
Can reliably form the fine void removal part (stirring part) with higher quality.
I can .

Furthermore, prior Symbol stirring pin exhibits a cross-section triangular or polygonal column, a friction stir tool (claim 3) are also included in the present invention. According to which this, the contact area between the stirring pin itself of the metal members and cast surface increases, the trajectory including a moving circular rotary continuous stirring pin draws a wide joint or microvoids removal unit (stirring Part) can be reliably formed with higher quality . In addition, the axis of the tool body
The eccentric distance of the shaft center of the stirring pin with respect to
Also developed a friction stir tool (Claim 4) with a diameter of 5% or more.
Included in the Ming . According to this, a wide joint or fine
The void removing portion can be formed more reliably. In addition, above
If the eccentric distance is less than 5% of the diameter of the stirring pin,
Rotation trajectory is not much different from the conventional stirring tool.
Relatively high accuracy is required for positioning the stirring tool
Therefore, this range is excluded. In other words,
The upper limit of the center distance is less than 40% of the diameter of the stirring pin .

A friction stir tool (claim ) wherein the tool body and the stirring pin are made of separate members and are integrated by inserting the base end of the stirring pin into at least a hole opened on the bottom surface of the tool body. Item 5) is also included in the present invention. According to this, by inserting the base end side of the stirring pin into a hole opened on the bottom surface or a hole penetrating from the bottom surface to the upper end surface of the tool main body and fixing the same, the friction stir tool is subjected to a normal cutting process. For example, it can be easily manufactured.
In order to fix the base end side of the stirring pin inserted into the hole or the hole, a small-diameter fixing pin may be driven from the peripheral surface of the tool body. Also, a female screw may be cut into the hole or the inner peripheral surface of the hole, and a proximal end of a stirring pin into which a male screw is cut in advance may be screwed into the screw. May be typed.

Further, the tool main body is a cylindrical body including a peripheral portion of a bottom surface thereof, and the stirring pin includes a large-diameter base portion, and is provided eccentrically from an axis of the base portion at the bottom surface of the base portion. in the hollow portion of the tool body of the body together with the base of the stirring pin is inserted, a portion containing the tool body and the agitating pins are rotatable individually, friction stir tool (claim 6) the present invention include.
Alternatively, the tool body is a cylindrical body including a peripheral portion of the bottom surface and has a hollow portion eccentric with respect to the axis thereof, and has a stirring pin in the hollow portion on the bottom surface, and has a large diameter coaxial with the stirring pin. The present invention also includes a friction stir tool (claim 7) in which the base portion is inserted and the tool main body and the portion including the stirring pin are individually rotatable. According to these, the stirring pin in the friction stir tool can be made to rotate planetarily at a higher speed than the tool body, so that insufficient flow of the metal member on the high melting point side to be joined by the stirring pin is easily eliminated. Therefore, for example, by inserting the stirring tool while rotating from the surface of the metal member on the low melting point side along the superposed surface of two metal members having different melting points, the internal member straddles the superposed surface of both metal members. It is possible to reliably form a healthy joint without defects and surface defects.

[0013] On the other hand, the bonding method of the present invention (claim 8) includes a step of abutting or overlapping a pair of metal members;
A step of rotating and moving the friction stir tool along an abutting surface or an overlapping surface of the pair of metal members to friction stir weld the pair of metal members. According to this, the stirring pin forms a locus including continuous circular rotation and movement along the abutting surface or the overlapping surface of the pair of metal members. Therefore, compared with the conventional stirring tool, a wider and more healthy joint can be surely formed and joined without requiring positioning accuracy or a sensor.

Further, the method for removing minute voids on a casting surface according to the present invention (Claim 9) is characterized in that the friction stir tool is rotated and moved along the surface of the casting while the stirring pin of the tool is placed on the surface layer of the casting. Inserting. According to this, the stirring pin forms a trajectory including continuous circular rotation and movement along the casting surface, so that a wide fine gap removing portion (stirring portion) can be easily formed as compared with a conventional stirring tool. Can be formed. Therefore, fine voids on the casting surface including the surface layer can be efficiently removed with a small movement locus. The above castings are mainly intended for castings of aluminum or its alloys, but also include iron castings, steel castings, castings of titanium, copper and alloys thereof.

[0015]

Preferred embodiments of the present invention will be described below with reference to the drawings. Figure 1 (A), (B) is a perspective view and a cross-sectional view of a first friction stir tool 1 of the present invention. The friction stir tool 1 is made of, for example, a high-speed tool steel, and as shown in FIGS. 1A and 1B, a cylindrical tool body 3 including a circular bottom surface 4 and protrudes coaxially from an upper end surface thereof. Shank 2 and a stirrer projecting from the bottom surface 4 of the tool body 3 in parallel with the axis of the tool body 3 and having an axis at a position radially eccentric with respect to the axis of the tool body 3. And a pin 8. The shank 2 is fixed to a chuck in a joining device such as a lathe (not shown).

As shown in FIGS. 1 (A) and 1 (B), a female screw hole (hole) 5 is formed in the tool body 3 at a position offset from the center of the bottom surface 4 thereof. A male screw (screw) 9 at the base end side of the screw 8 is screwed in, and the tool body 3 is screwed.
The distal end of the fixing pin 6 driven into the through hole 7 communicating with the female screw hole 5 from the peripheral surface of the pin abuts on the base end side of the stirring pin 8. Thereby, the stirring pin 8 is fixed to the tool main body 3 and rotates integrally therewith. In the stirring pin 8, a male screw 9 at a portion protruding from the bottom surface 4 of the tool body 3 is used to increase a contact area with a metal member to be joined or a casting surface from which fine voids in a surface layer to be removed will be described later. Corresponds to unevenness.

FIG. 2 (A), (B) shows a bonding method using a first friction stir tool 1. First, an abutting surface 14 is formed by a process of abutting end surfaces of a pair of aluminum alloy plates (metal members) 11 and 12. Next, while rotating the tool body 3 and the stirring pin 8 of the friction stir tool 1 along the butting surfaces 14 of the pair of aluminum alloy plates 11 and 12, the bottom surface 4 of the tool body 3 is
A friction stir welding process is performed in which the stirring pins 8 are pressed against the surfaces of the first and second surfaces 12 and the stirring pins 8 are inserted near the abutting surfaces 14. On this occasion,
The axes of the tool main body 3 and the stirring pin 8 of the stirring tool 1 are arranged at an angle of about 3 ° in the direction opposite to the moving direction with respect to the perpendicular to the surfaces of the aluminum alloy plates 11 and 12. In addition, the friction stir tool 1 is 500 to 15000r.
The stirring pin 8 is inserted toward the vicinity of the abutting surface 14 while being rotated at a rotation speed of pm and applying a pushing force of 1 to 30 kN along the axis of the main body 3.
In FIG. 2A, the paper is sent to the right at a moving speed of 50 mm to 2 meters / minute.

As shown by the solid and broken lines in FIGS. 2 (A) and 2 (B), the stirrer pin 8 continuously rotates and linearly moves along the vicinity of the butting surfaces 14 of the aluminum alloy plates 11 and 12. Is formed. As a result, the male screw 9
The aluminum of the alloy plates 11 and 12 rubbed and heated by contacting with the stirring pin 8 having a plasticized fluidization with the abutting surface 14 interposed therebetween. At this time, the bottom surface 4 of the tool main body 3 is pressed against the surfaces of the alloy plates 11 and 12 and presses down the surfaces of the joints W which are sequentially formed, thereby preventing the plasticized fluidized aluminum from scattering. For this reason, the friction stir tool 1 has a joining surface W having a wider cross section than the conventional stirring tool 70 shown in FIG.
4 can be reliably formed.

Accordingly, the aluminum alloy plates 11 and 12 can be firmly joined via the wide and sound joints W. In addition, the axis of the tool body 3 is
The aluminum alloy plates 11 and 12 can be reliably bonded by the bonding portion W having a wide cross section even if they are slightly displaced to either of the two sides. The first stirring tool 1 as described above can also be applied to a method for removing fine voids on a casting surface described later. The rotational speed of the friction stir tool 1 can be increased in proportion to the increase in the amount of eccentricity (distance) of the stirring pin 8 as compared with the rotational speed of the conventional stirring tool 70 that is not eccentric. It is understood that there is a necessary tendency. However, it is important to set the optimum rotation speed even in consideration of various conditions such as the material and thickness of the metal member to be joined, the pushing force of the friction stir tool, and the moving speed.

[0020]

Here, an embodiment of the joining method of the present invention using the friction stir tool 1 will be described. The agitating pin 8 is made of SKD 61, the diameter of the tool body 3 is 15 mm, the diameter of the stirring pin 8 having the M5 male screw 9 is 5 mm and the length is 4 mm, and the axis of the stirring pin 8 with respect to the axis of the tool body 3 The friction stir tools 1 of Examples 1 to 3 in which the amount of eccentricity was changed in the range of 0.5 to 1.5 mm were prepared. Also, SK
D61, the dimensions of each part are the same as above, and the tool body 3 and the stirring pin 8 are the same as in the conventional stirring tool 70.
And a stirring tool of Comparative Example 1 were formed in a coaxial center. Furthermore, it consists of the same material as above and the dimensions of each part,
A stirring tool of Comparative Example 2 in which the amount of eccentricity between the tool body 3 and the stirring pin 8 was 2.0 mm was also prepared.

The friction stir tools 1 of Examples 1 to 3 and the stirring tools of Comparative Examples 1 and 2 were rotated along the butting surfaces of a pair of aluminum alloy (JIS: A6061-T5) plates having a thickness of 4 mm. 1400 rpm, moving speed 300 m
m / min, and a joining method involving rotation, pushing and moving by applying a pushing force of 6 kN to a linear length of 50 cm
Individually. The joint W joined by the stirring tool (1) of each example was observed from the cut surface to evaluate the quality. The results are shown in Table 1. Further, in the stirring tool (1) of each example, from the butting surface 14 to the axis of the stirring pin 8 when the butting surface 14 and the rotating stirring pin 8 can intersect and practical friction stir welding can be performed. Table 1 also shows the longest distances as the allowable limit deviation amounts.

[0022]

[Table 1]

According to the results shown in Table 1, in Examples 1 to 3 using the friction stir tool 1 of the present invention, a sound joint W (○) having a wide cross section and no defects such as poor fusion was obtained. Obtained. On the other hand, in Comparative Example 1, since the tool body 3 and the stirring pin 8 are coaxial, a sound but narrow joint W (Ｗ) is provided.
It became. Further, in Comparative Example 2, the eccentricity was increased to 40% of the diameter of the stirring pin 8, and the vibration of the stirring tool and the load on the rotating device became excessive, so that the joining operation itself was insufficient ( X). From the above results, the effect of the friction stir tool 1 of the present invention in which the eccentric distance of the stirring pin 8 with respect to the axis of the tool body 3 is 5% or more in diameter of the pin 8 is supported. In addition, the upper limit of the amount of eccentricity is 40
%, Desirably 30% or less, but the upper limit may be increased by improvements in optimizing the joining device to which the stirring tool 1 is attached.

FIGS. 3A and 3B are a perspective view and a sectional view of a second friction stir tool 1a of the present invention . The friction stir tool 1a includes a cylindrical tool main body 3 including a circular bottom surface 4 made of the same tool steel as described above, a shank 2 projecting coaxially from the upper end surface thereof, and the tool main body 3 from the bottom surface 4 of the tool main body 3. A stirring pin 8a projecting in parallel with the axis of the tool body 3 and having an axis eccentric in the radial direction with respect to the axis of the tool main body 3; The stirring pin 8a is a hexagonal pillar having a regular hexagonal cross section, and the base end side of the stirring pin 8a is inserted into a hexagonal hole (hole) 5a formed at a position shifted from the center of the bottom surface 4 of the tool body 3, The tip of the fixing pin 6 driven into the through hole 7 communicating from the peripheral surface of the tool body 3 is a stirring pin 8
The stirring pin 8a is fixed by abutting on the base end side of a.

As shown in FIGS. 3A and 3B, the bottom surface 4 of the tool main body 3 is provided with a spiral ridge 4a having at least one turn from the periphery toward the center. Have been. The ridge 4a has an outer end at a periphery of the bottom surface 4 at a position away from the stirring pin 8a so as not to intersect with the stirring pin 8a, and is slightly closer to the stirring pin 8a in the middle. 4 has its inner end located near the center. By providing the spiral ridge 4a, the contact area in the vicinity of the bottom surface 4 of the tool body 3 is increased, and the situation where the metal material of the plasticized fluidized metal member is scattered to the outside and overflows is prevented. Surface defects in the part can be reliably prevented. Therefore, the friction stir tool 1a can be moved while rotating in a vertical position with respect to the surface of the pair of metal members to which the tool body 3 is to be joined or the surface of the casting from which fine voids are to be removed. Therefore, the operation itself of the friction stir tool 1a becomes easy.

FIGS. 4A and 4B show a method of removing fine voids on the surface 16 including the surface layer of the aluminum alloy casting (casting) 15 using the second friction stir tool 1a. FIG.
As shown in the plan view of FIG.
Along the surface 16 of the tool body 3 and the stirring tool 1a including the stirring pin 8a having a regular hexagonal cross section projecting eccentrically from the center of the bottom surface 4 of the tool body 3 and linearly moving rightward in FIG. 4 (A). Then, a U-turn is made just before the right end of the surface 16 and the surface 16 is linearly moved leftward. At this time, the stirring tool 1
a is rotated at a rotation speed of 500 to 15000 rpm,
In addition, while a pushing force of 1 to 30 kN is applied to the surface 16 of the casting 15 along the axis thereof, the stirring pin 8a is inserted toward the surface layer of the casting 15 and, as shown in FIG. It is sent at a moving speed of 50 mm to 2 meters / min.

As shown in FIG. 4 (A), a stirrer (fine void removing unit) W1, a U-turn type stirrer Wt, and a stirrer W2 are formed at the mark where the stirring tool 1a has passed. As shown in the vertical sectional view of FIG. 4B, the adjacent stirring portions W1 and W2 partially overlap. As shown by a solid line and a broken line in FIG. 4B, the stirring pin 8a forms a trajectory including a continuous circular rotation and linear or curved movement along the vicinity of the surface 16 of the aluminum alloy casting 15. As a result, the aluminum of the casting 15 rubbed and heated in contact with the stirring pin 8 a plastically fluidizes near the surface 16. At this time, the bottom surface 4 of the tool body 3 is pressed against the surface 16 of the casting 15 and presses the surface of the agitating portion W to prevent the plasticized aluminum from scattering. Therefore, the friction stir tool 1a can surely form the stirring section W having a wider cross section along the vicinity of the surface 16 as compared with the conventional stirring tool 70 shown in FIG.

Therefore, a fine gap of about 0.1 mm existing in the vicinity of the surface 16 of the casting 15 can be removed to form a wide and sound stirring portion W and to have a dense structure.
Further, even if the axis of the tool body 3 is slightly deviated from the planned movement trajectory, the stirrer W having a wide cross section provides
The structure near the surface 16 of the aluminum alloy casting 15 can be reliably modified. Furthermore, the spiral ridges 4a prevent the aluminum of the plasticized and fluidized casting 15 from scattering and overflowing in the vicinity of the bottom surface 4 of the tool body 3 and reliably generate surface defects in the stirring section W. Can be prevented. Therefore, the tool main body 3 can be moved vertically while rotating the friction stir tool 1a with respect to the surface 16 of the casting 15 from which the minute gap is to be removed, so that the operation itself of the stirring tool 1a is also easy. Becomes The above-described second stirring tool 1a can be applied to the above-described method of joining a pair of metal members.

FIG. 5 (A), (B), the first different embodiment, the
2 relates to a friction stir tool 30. Friction stir tool 30
As shown in FIG. 5 (A), is made of, for example, high-speed tool steel and includes a separate cylindrical tool body 31 and a stirring pin portion 36. The tool body 31 is a cylindrical body 32 including a peripheral portion of the bottom surface 34 and having a hollow portion 33 having a coaxial center therein. In addition, the stirring pin portion 36 is arranged as shown in FIG.
As shown in (A) and (B), a bearing 35 is provided in the hollow portion 33.
And a stirring pin 38 protruding from a position eccentric from the axis of the base 39 on the bottom surface 37 thereof. The tool main body 31 and the stirring pin portion 36 are individually connected to a dedicated driving source such as a motor. A heat-resistant sealing material (not shown) is arranged near the tip between the tool body 31 and the stirring pin portion 36. Also, the cylinder of the tool body 31
The above-mentioned spiral ridge 4a is formed on the bottom surface 34 of the body 32.
Is protruding.

FIGS. 5C and 5D relate to a friction stir tool 40 having a further different form. The friction stir tool 40 includes a separate cylindrical tool body 41 made of tool steel and a stirring pin portion 46. As shown in FIGS. 5C and 5D, the tool main body 41 is a cylindrical body 42 including a peripheral portion of a bottom surface 44 thereof and having a hollow portion 43 having an axis at an eccentric position. The stirring pin portion 46 includes a base 49 of a large diameter which is rotatably received through a bearing 45 in the hollow portion 43, protruding from the axis and coaxial position of the base portion 49 in its bottom surface 47 including was a stirring pin 48, a.
Also, the bottom surface 44 of the cylindrical body 42 of the tool body 41
The above-mentioned spiral ridge 4a protrudes. That's all
The tool main body 41 and the stirring pin portion 46 are individually connected to a dedicated driving source such as a motor, and a heat-resistant sealing material (not shown) is arranged near the tip between the two.

FIGS. 6A and 6B show the friction stir tool 30,
The bonding method using No. 40 will be described. As shown in FIG.
First, an overlapping surface 19 is formed by a step of overlapping and restraining an aluminum alloy plate (metal member) 17 and an oxygen-free copper plate (metal member) 18 having a higher melting point. Next, in the vicinity of the surface of the aluminum alloy plate 17, the stirring tool 30 is disposed at an angle in the same manner as described above. At this time, while the stirring pin portion 36 is being rotated at a higher rotation speed than the tool main body 31, the friction stir tool 30
And a stirring pin 38 is placed on the surface 1
9 and the joining tool 30 is moved at a moving speed of 50 mm to 2 meters / minute in the forward direction in FIG. In the friction stir welding process, the stirring pin 38 moves while performing a planetary rotation of a circular locus near the overlapping surface 19 as shown by a solid line and a broken line in FIG.

In the above joining step, the aluminum alloy plate 17 is attached to the bottom surface 34 of the cylindrical body 32 in the tool body 31.
And the bottom surface 37 of the stirring pin portion 36 and the stirring pin 3
8 comes into contact with the portion near the base end and generates heat by friction and becomes plastic and fluid. At the same time, the oxygen-free copper plate 18 also comes into contact with the portion near the tip of the stirring pin 38 that performs the planetary rotation of the circular locus and generates frictional heat to plasticize and fluidize. At this time, the stirring pin part 3
6 rotates at a higher rotational speed than the tool main body 31, so that the heat generation of aluminum and copper in the peripheral portion of the stirring pin 38 increases. Therefore, the resistance when the stirring pin 38 moves along the eccentric trajectory can be reduced. As a result, the aluminum alloy plate 17 and the oxygen-free copper plate 1
In FIG. 8, a joint W having a wide cross-section is formed in which both metals and alloys are mixed and solidified in a mixed state as the stirring tool 30 is separated from each other. Moreover, the oxygen-free copper plate 18
Frictional contact with a portion near the tip of the stirring pin 38 increases the amount of heat generated in accordance with the increase in the number of rotations, so that insufficient flow can be eliminated. This makes it possible to form a healthy joint W without internal defects (cavities) along the longitudinal direction of the superposed surface 19.

As shown in FIG. 6 (B), the butted surface 14 is formed by a process of butting and restraining the thick aluminum alloy plates 11 and 12. Next, near the surfaces of the aluminum alloy plates 11 and 12, the stirring tool 40 is disposed at an angle in the same manner as described above. Stirring tool 40
Is rotated and moved by the same pushing force and the moving speed as described above. In this friction stir welding step, the stirring pin 48 moves while performing a planetary rotation of a circular locus along the vicinity of the butting surface 14 as shown by the solid line and the broken line in FIG. As a result, the aluminum alloy plates 11 and 12 come into contact with the bottom surface 44 of the cylindrical body 42 of the tool body 41 and the bottom surface 47 and the stirring pin 48 of the stirring pin portion 46 to generate frictional heat and plastically flow.

As a result, as shown in FIG. 6B, a wide and deep cross-section W is formed across the butting surface 14 where both aluminum alloys are solidified in a mixed state. That is, the butting surfaces 14 of the aluminum alloy plates 11 and 12
The heat generation amount also increases in accordance with the increase in the rotation speed of the stirring pin 48 at the portion near the rear surface opposite to the front surface where the stirring pin 48 enters, and thus, insufficient flow can be eliminated. Therefore, it is possible to form a healthy joint W without internal defects along the butting surface 14. Moreover,
Since the stirring pin portion 46 rotates at a higher rotation speed than the tool main body 41, the amount of heat generated by the aluminum around the stirring pin 48 increases. Therefore, the stirring pin 48
Can also reduce the resistance when moving along the eccentric orbit. Further , bottom surfaces 34, 44 of cylindrical bodies 32, 42 of tool bodies 31, 41 of friction stir tools 30, 40, respectively.
Due to the projecting the spiral projections 4a described above, the Ru can be advanced the stirring pin 38, 48 by the stirring tools 30 and 40 in a vertical posture in the aluminum alloy plates 11 and 12 and the like. In addition , the stirring tool 30 can be applied to butt joining, the stirring tool 40 can be applied to overlap joining, and both can be applied to the method for removing fine voids on the casting surface.

FIG. 7 relates to a first friction stir tool 50, 60 of the application. As shown in FIGS. 7A and 7B, the friction stir tool 50 is a cylindrical tool body 51 made of high-speed tool steel and the tool body 51 on the bottom surface 52 thereof.
And a pair of ridges (irregularities) 55 projecting from the tip end surface 54 of the stirring pin 53 along the radial direction and exhibiting a cross shape.
By providing the protruding ridge 55 to increase the contact area, in combination with the stirring pin 53 that forms a locus of circular rotation, the metal members can be more firmly joined, or fine voids on the casting surface can be more reliably removed. It is possible to do.
As shown in FIGS. 7 (C) and 7 (c), a large number of fine cubic projections (irregularities) 56 are provided on the tip end surface 54 of the stirring pin 53 in a grid pattern. As shown in (d), ring projections (irregularities) 57, 58,
Even in a configuration in which the projections 59 are provided concentrically, the same operation and effects as those of the pair of ridges 55 can be obtained in the cross shape.

Further, as shown in FIGS. 7E, 7E, and 7F, the friction stir tool 60 includes a cylindrical tool body 62.
And a stirring pin 66 protruding at a position eccentric from the axis of the tool main body 62 on the bottom surface 64 of the tool body 62, and a plurality of stirring pins 66 on the peripheral surface of the stirring pin 66 near the front end surface 67 along the axial direction. A concave groove (irregularity) 68 is formed. With the concave groove 68, the same operation and effect as those of the above-mentioned convex strip 55 can be obtained. In addition, a large number of dents may be formed in the form of scattered spots instead of the above-mentioned grooves 68, or, together with the grooves 68 and dents on the peripheral surface of the stirring pin 66, the ridges 55, 55
It is also possible to provide the projection 56 or the ring ridges 57, 58, 59 and the like. Also, the ridge 55, the projection 56,
Alternatively, the ring ridges 57, 58, 59 are connected to the stirring pins 8, 8a, 38, of the friction stir tools 1, 1a, 30, 40, respectively.
48 may be applied.

The present invention is not limited to the embodiment and the embodiment described above. For example, as shown in FIG.
The butting surface 14 shown in FIG. 3B is not limited to a straight line shape in plan view, but may also include a curved line or an L-shaped or bent shape in the middle. The surfaces of the stirring portions W1, Wt, W2 formed on the surface 16 of the casting 15 shown in FIG. 4 may be used as they are, but the stirring portions W1, Wt, W
A finishing process for cutting the vicinity of the surface may be performed so as to leave most of the two. Further, when the friction stir tool 1a moves on the surface 16 of the casting 15 shown in FIG. 4 (A), an acute angle or an obtuse angle turn is included between the linearly moving parts (W1, W2), or in plan view. The whole may be a rectangular spiral moving trajectory. The surface of the casting 15 is not limited to the flat surface 16, but includes a protruding curved surface with a gentle curve or a concave curved surface. Various movement patterns involving rotation of the friction stir tools 1, 1a, 30, 40, 50, and 60 are stored in advance in a RAM or the like of a personal computer that controls the tools, and the length of the linear movement and the length of U are stored. The diameter of a turn or the like can be input at any time, and the joining method and the fine void removing method of the present invention can be automated.

[0038]

The first friction stir tool of the present invention
According to (claim 1), the stirring pins, for moving while forming a large circular rotation path than the stirring pin diameter about the axis of the body with the rotation of the tool body, according The stirring pin forms a trajectory including continuous circular rotation and linear or curved movement along the abutting surface or the overlapping surface of the pair of metal members, or along the casting surface. For this reason, it is possible to easily form a joining portion or a fine void removing portion (stirring portion) having a wider cross section than a conventional stirring tool. In addition, the peripheral surface and the tip surface of the stirring pin are uneven.
Increases the contact area with metal members and casting surfaces
In order to reduce the size of the joints,
(Stirring part) can be formed more reliably with higher quality.
Therefore, it is easy to reliably perform high-quality friction stir welding without requiring positioning accuracy of the stirring tool or to provide a sensor, or to efficiently remove fine voids on the surface of a casting including a surface layer.

Further, in the present invention, the second friction stir tool is used.
According to the second aspect of the present invention, a wide cross-section is joined as described above.
Part or minute void removal part (stirring part) can be easily formed
In both cases, a spiral ridge is provided on the bottom of the tool body
The tool body perpendicular to the surface of the metal member or casting
Since the contact can be made in a posture,
Rotation and movement operations can be easily performed. I
The tool body is perpendicular to the surface of the
Because it can be brought into contact in a posture,
Rotation and movement operations can be easily performed. Change
, According to the friction stir tool of claim 3, the contact area between the stirring pin itself of the metal members and cast surface is further increased, the trajectory including a moving circular rotary continuous stirring pin draws a wide cross-section Joint or fine void removal part
(Stirring part) can be formed more reliably with higher quality .

Further, according to the friction stir tool of the sixth and seventh aspects, since the stirring pin can be rotated at a higher speed than the tool body and in the planetary rotation, the metal member on the high melting point side to be joined by the stirring pin. Insufficient flow is easily resolved. For this reason, for example, by inserting the stirring pin of the stirring tool from the surface of the metal member on the low melting point side while rotating along the overlapping surface of two metal members having different melting points, the two metal members are overlapped. It is possible to reliably form a sound joint having no internal defect and no surface defect over the surface.

On the other hand, according to the joining method of the present invention (claim 8) , the stirring pin of the friction stir tool including the unevenness and the spiral ridge is provided on the abutting surface or the overlapping surface of the pair of metal members. Along the trajectory, including a continuous circular rotation and movement. For this reason, it is possible to reliably form and join a wider and sounder joint than a conventional stirring tool without requiring positioning accuracy. Further, according to the method of microvoids removal casting surface of the present invention (claim 9), wherein the concave
The stirring pin including the convex or spiral ridges forms a trajectory including continuous circular rotation and movement along the casting surface, so that a fine void removing portion (stirring portion) that is wider than a conventional stirring tool is used. ) Can be easily formed. Therefore, fine voids on the casting surface including the surface layer can be efficiently removed with a small movement locus.

[Brief description of the drawings]

FIG. 1A is a perspective view showing one embodiment of a first friction stir tool of the present invention, and FIG. 1B is a sectional view thereof.

2A is a schematic view showing a joining method of the present invention using the friction stir tool of FIG. 1, and FIG. 2B is a cross-sectional view taken along a line BB in FIG.

FIG. 3A shows a second friction stir tool according to the present invention.
FIG. 2 is a perspective view showing one embodiment, and FIG.

4A is a plan view showing a method for removing fine voids on a casting surface of the present invention using the friction stir tool of FIG. 3, and FIG. 4B is a plan view of FIG.
Sectional drawing of the viewing angle along BB line in a middle.

FIGS. 5A to 5D show the differences between the first and second friction stir tools.
FIG. 2 is a cross-sectional view or a perspective view showing a configuration of the present invention.

6 (A), (B) is a schematic view illustrating a bonding method using a stirring tool rubbing friction in FIG.

FIGS. 7A and 7B are graphs showing responses in a first friction stir tool.
Side view or a perspective view of a use form, (C), (D) is a bottom view showing the unevenness of different forms, (c) is a side view of the form of (C), (d)
Is a cross-sectional view at a viewing angle along the line dd in (D),
(E), (F) is a side view or a perspective view showing a stirring tool of still another applied form, and (e) is a cross-sectional view taken along a line ee in (E).

8A and 8B are schematic diagrams showing a joining method using a conventional friction stir tool, and FIG. 8C is a schematic diagram showing the vicinity of an obtained joint.

[Explanation of symbols]

1, 1a, 30, 40, 50, 60 ... friction stir tool 3, 32, 42, 51, 62 ... tool body 4, 34, 37, 44, 47, 52, 64 ... Bottom 4a ……………………… Protrusion 5,5a ………………… Female screw hole /
Hole (hole) 8, 8a, 38, 48, 53, 66 Stirring pin 9 Male screw (screw: concave and convex) 11, 12, 17 ... aluminum alloy plate (metal member) 14 ... butting surface 15 ... …………………………………………………………………………………………………… Surface 18 …………………………………… …………… Oxygen-free copper plate
(Metal member) 19 ..................... Overlapping surfaces 33, 43 ... Hollow portions 36, 46 …………………………… Stirring pin part
(Part including stirrer pin) 39, 49 ……………………………………………………………………………………………………………………………………………. ………………………………………………………………………………………………………………………… (Protrusions) 57,58, 59 …………………… Ring ridge
(Unevenness) 68 …………………………………… Dove groove (unevenness)

──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Shinya Makita 1-34-1, Kabara, Kambara-cho, Anbara-gun, Shizuoka Prefecture Nippon Light Metal Co., Ltd. Group Technology Center (56) References JP-A-2002-79383 (JP, A WO01 / 028731 (WO, A1) UK Patent Application Publication 2306366 (GB, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) B23K 20/12 B22D 29/00

Claims (9)

(57) [Claims] 1. A tool body including a circular bottom surface, and a stirring pin protruding from the bottom surface of the tool body and having an axis parallel to and eccentric to the axis of the tool body. At least one of the peripheral surface and the tip surface of the stirring pin.
A friction stir tool characterized by having irregularities including a dip . 2. A tool body including a circular bottom surface, and an axis of the tool body projecting from the bottom surface of the tool body.
Has an axis parallel to the center and eccentric to the axis
And a stirrer pin, on the bottom surface of the tool body, from the periphery of the bottom surface.
A spiral ridge protruding toward the center is projected.
Friction stirring tool that, it said that. 3. A polygonal column having a cross section of not less than a triangle having a stirrer pin.
The exhibits, friction stir tool according to claim 1 or 2, characterized in that. 4. A stirrer pin with respect to an axis of said tool body.
The eccentric distance of the axis is at least 5% of the diameter of the stirring pin.
That the friction stir tool according to any one of claims 1 to 3, characterized in that. 5. The tool body and the stirring pin are separate members.
And at least a hole that opens in the bottom of the tool body
The friction stir tool according to any one of claims 1 to 4, wherein a base end side of the stirring pin is inserted and integrated . 6. The tool body includes a peripheral portion on a bottom surface thereof.
And the stirring pin includes a large-diameter base.
And it is eccentrically protruded from the axis at the bottom of this base.
The above-mentioned inside the hollow part in the tool body of the cylindrical body
While the base of the stirring pin is inserted,
The friction stir tool according to any one of claims 1 to 4 , wherein a portion including the stirring pin is rotatable individually . 7. The tool body includes a peripheral portion on a bottom surface thereof.
Having a hollow portion that is eccentric with respect to its axis ,
This hollow portion has a stirring pin on the bottom surface and
A coaxial core with a large diameter base is inserted, and the tool
The body and the part containing the stirring pin are rotatable individually.
That the friction stir tool according to any one of claims 1 to 4, characterized in that. 8. A method for abutting or overlapping a pair of metal members.
And abutting or overlapping surfaces of the pair of metal members.
Moving the friction stir tool of claims 1 to 7 along with
To move the pair of metal members by friction stir welding.
And a joining step . 9. A friction stirrer according to claim 1 along the surface of the casting.
While rotating and moving the stirring tool,
A method for removing fine voids on the surface of a casting , comprising inserting a casting into a surface layer of the casting .