JP2000176658A - Treatment of friction agitation joining end - Google Patents

Abstract

PROBLEM TO BE SOLVED: To simply and surely plug a taken-out hole and to improve the strength and external appearance of a joined product by filling, fusing, solidifying, solder or brazing filler metal into the hole, which is generated by lifting up a working head at a joining final end, thereby integrating them into one body. SOLUTION: A working head 20 of a friction agitation joining tool 2 is relatively advanced while rotating at an embedded state, metal plates 1 are joined to one body. At this joining final end, the working head is lifted up to pull up an embedded probe 21 and a taken-out hole 3 corresponding to the probe 21 is produced at the joining final end of an obtained joined part 10. Solder or brazing filler metal 4a is filled in the taken out hole 3, the solder or brazing filler metal are fused/solidified. By this method, the joined part 10, in which the taken-out hole 3 is filled with fused/solidified solder or brazing filler metal 4b, has an uniform surface a taken-out hole shape eliminated with, is excellent in an external appearance and does not have stress concentration to a taken out hole position, the high strength joined part is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a processing method for closing a hole formed at the end of a joint when a material to be joined is integrally joined by a friction stir welding method.

[0002]

2. Description of the Related Art In recent years, friction stir welding (Friction) has been used as a new joining method instead of welding or brazing of metal materials.
n Stir Welding) method has appeared. This joining method is, for example, as disclosed in Japanese Patent Publication No. 7-505090, when a probe (rod) made of a material harder than the workpiece is rotated and brought into sliding contact with the workpiece. Since the workpiece material plastically fluidizes due to frictional heat and pressure generated in the sliding contact portion, the probe is embedded in the workpiece and can be moved in the workpiece in the embedded state. It is based on what is becoming.

For example, as shown in FIG. 1, a metal plate (1)
(1) When butting and joining together, a friction stir welding tool (2) having a protruding shaft-shaped probe (21) at the tip of a processing head (20) is used.
While rotating 0) at a high speed, the probe (21) is buried by pressing against the start end of the joining line (L), and is moved along the joining line (L) as shown by the arrow. As a result, the material of the metal plates (1) (1) plastically flows due to frictional heat and pressure on the front side of the advancing probe (21), and gradually moves to the rear side of the probe (21) while being stirred and kneaded. The rear side loses frictional heat and rapidly cools and solidifies. Therefore, the two metal plates (1) and (1) are joined in a state where the base metals are completely kneaded by stirring and kneading.

In this case, the temperature at which the metal material plastically flows is much lower than the melting point, and the joining falls into the category of solid-phase joining. Therefore, the amount of heat input to the metal material during the joining process is small, and the stress accompanying solidification shrinkage is reduced. Since there is no generation, there is an advantage that deformation or cracking due to thermal strain near the joint is less likely to occur.
Although FIG. 1 shows an example in which the processing head side is moved, there is also a method in which the processing head side is moved and, conversely, the workpiece is joined by a processing head arranged at a fixed position.

[0005]

However, in such friction stir welding, as shown in FIG. 2A, the probe (21) which has been lifted up at the end of welding and has been embedded is used. When it is pulled out, a hole (3) corresponding to the probe (21) will be formed at the joint end,
Since the stress concentrates on the hole (3), the strength of the joined product is reduced and the appearance is deteriorated. Therefore, there is a problem that various problems are caused in the application and the commercial value is reduced.

The present invention has been made in view of the above circumstances, and has as its object to provide a processing method capable of easily and surely closing a hole formed at the end of welding in friction stir welding to greatly improve the strength and appearance of a joined product. The purpose is.

[0007]

According to a first aspect of the present invention, there is provided a method of processing a friction stir welding end, wherein a processing head of a friction stir welding tool is rotated while being embedded in an embedded state. In the friction stir welding in which the materials to be joined are joined and integrated by proceeding to, the holes formed by pulling up the processing head at the end of the joint are filled with solder or brazing material, and these solders or brazing materials are melted. It is characterized by being solidified and integrated with the material to be joined.

According to this processing method, since the solder or brazing filler material filled into the holes at the end of the friction stir welding is a low melting point material, the residual heat remaining in the material to be joined after the friction stir welding, this residual heat and the external heating Alternatively, the filler can be easily melted only by external heating, and a new surface can be formed at the position of the hole by solidification. Accordingly, the obtained joint product has excellent appearance in appearance due to the disappearance of the initial holes, and also has a high strength due to the absence of stress concentration at the positions of the holes.

According to a second aspect of the present invention, in the method for treating the end of friction stir welding of the first aspect, the hole is filled with a Zn-Al-based solder mainly composed of Zn. In this case, since the Zn-Al-based solder used has a particularly low melting point, if it is filled in the above-mentioned hole immediately after the end of the friction stir welding, it is melted only by the residual heat at the time of the friction stir welding remaining in the workpiece. It is possible.

According to a third aspect of the present invention, in the method of the first aspect, the Al-S
An i-type or Al-Cu-type brazing material is filled and melted by heating. In this case, since the brazing material to be used has a relatively high melting point, it is necessary to heat with a burner or the like after filling the holes, but if the filling and heating are performed immediately after the completion of the friction stir welding, the friction stir welding can be performed. Since there is extra heat, less heating is required.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a method for treating the end of friction stir welding according to the present invention will be described below with reference to FIGS.
This will be specifically described with reference to FIG.

FIG. 2 (A) shows the processing head (1) at the end where metal plates (1) and (1) made of aluminum or its alloy are joined by friction stir welding (see FIG. 1). A state in which a hole (3) corresponding to the probe (21) is formed at the bonded end of the obtained bonded product (10) by pulling up the probe (21) by pulling up the 20) and extracting the embedded probe (21).

In order to carry out the process of the joint termination, first, FIG.
As shown in (B), the holes (3) are filled with solder or brazing material (4a). Then, the filled solder or brazing material (4a) is melted and solidified. As a result, as shown in FIG.
Is filled with the molten or solidified solder or brazing material (4b), has a uniform surface in which the shape of the original hole (3) has disappeared, is excellent in appearance, and has no stress concentration at the position of the hole. Therefore, the strength becomes large.

Here, the above solder or brazing material (4a)
Is a low melting point material, and can be easily melted by external heating using a burner or a heating iron after filling the holes (3), but using the residual heat of friction stir welding as a heat source for this melting it can. That is, in friction stir welding, frictional heat is generated along with the welding, and immediately after the welding is completed, the surroundings of the hole (3) are considerably high due to residual heat remaining in the material. Is selected, and filling is performed immediately after the above-mentioned process, it is possible to melt only by residual heat without external heating. In addition, even if the material cannot be melted by only the residual heat, if the material is filled into the hole (3) immediately after the end of the bonding and subjected to external heating, the degree and time of the heating can be reduced because the residual heat is applied. Processing efficiency is improved.

As the solder, for example, Zn-Al
Alloy, solder alloys such as Zn-Sn-based, Zn-Pb-based, and Sn-Pb-based alloys. And among these, Z
n-Al based solder (typical composition Zn9
(5 wt%, Al 5 wt%) has a very low melting point and is particularly recommended if it is filled in the hole (3) immediately after the end of the friction stir welding because it can be reliably melted only by residual residual heat.

Further, as the above brazing material, for example, Al
Alloys for brazing materials such as -Si-based and Al-Cu-based alloys. These brazing materials generally have a higher melting point than solder,
Since it is difficult to melt only by the residual heat of the friction stir welding, it is preferable to melt by heating with a burner or the like after filling the holes (3). However, even in this case, if the filling and heating are performed immediately after the end of the friction stir welding, the amount of heating can be reduced because there is residual heat of the friction stir welding.

The solder or brazing material used (4a)
In FIG. 2, a pin-shaped member is illustrated, but a granular or powder-shaped member may be used, and a wire or a rod may be inserted into the hole (3). The filling amount of the solder or brazing material (4a) into the hole (3) should be set so that the surface after melting and solidification substantially matches the surface level of the material to be joined (1). is there.

[0018]

According to the method for processing the end of friction stir welding according to the first aspect of the present invention, a solder or brazing material is filled into a punched hole formed at the end of joining of materials to be joined by friction stir welding. Since it is solidified and integrated with the material to be joined, it is possible to easily and surely close the hole to provide a joined product having excellent appearance and strength, and to utilize the residual heat of friction stir welding as a heat source for the melting. Thus, the processing efficiency can be improved.

According to the second aspect of the present invention, in the above-described method of processing the end of friction stir welding, since the material to be filled in the hole has a particularly low melting point, the filling is performed immediately after the end of the friction stir welding. Melting can be performed only by residual heat remaining in the material to be joined, and thus there is an advantage that external heating can be omitted to shorten the processing steps and reduce processing costs.

According to the third aspect of the present invention, in the above-described method of processing the end of friction stir welding, the material filled in the hole is melted by external heating, but the filling and heating are performed immediately after the completion of the friction stir welding. Thereby, the degree and time of heating can be reduced.

[Brief description of the drawings]

FIG. 1 is a perspective view showing joining of metal plates by friction stir welding.

FIGS. 2A and 2B show an embodiment of a method of processing the end of friction stir welding according to the present invention. FIG. 2A is a longitudinal side view of a joined product having a hole at the end of friction stir welding, and FIG. FIG. 4C is a vertical sectional side view of a state in which a solder or a brazing material is filled in a hole of the joint, and FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Metal plate (material to be joined) 10 ... Joined goods 2 ... Friction stir welding tool 20 ... Processing head 21 ... Probe 3 ... Hole 4a ... Filled solder or Brazing material 4b ・ ・ ・ Solder or brazing material after melting and solidification

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C22C 21/00 C22C 21/00 D

Claims (3)

[Claims] 1. In friction stir welding, in which a processing head of a friction stir welding tool is relatively advanced while rotating in an embedded state to join and integrate materials to be welded together, by pulling up the processing head at the end of welding. Fill the resulting holes with solder or brazing material, melt these solder or brazing material,
A method of treating the end of friction stir welding, wherein the method is solidified and integrated with a material to be joined. 2. A Zn-A containing Zn as a main component in the hole.
2. The method according to claim 1, wherein the l-type solder is filled. 3. An Al—Si or Al—C hole is formed in the hole.
The method for treating the end of friction stir welding according to claim 1, wherein a u-type brazing material is filled and heated and melted.