JP3081799B2 - Aluminum material joining method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for joining aluminum materials used for manufacturing various aluminum structural materials, aluminum joints, aluminum joined products, and the like.
You.

[0002] In this specification, the term "aluminum" is used to include aluminum and its alloys. Further, the term "casting material" is used to include a die-cast material.

[0003]

2. Description of the Related Art When joining aluminum materials, the most common type is M
Conventionally, a fusion welding method such as IG or TIG has been employed.

[0004] However, the aluminum casting material is M
Melt welding by IG, TIG, etc. is difficult. For this reason, when manufacturing complex joint structures and special joints,
Since an aluminum cast material cannot be used, it has been necessary to join and join aluminum wrought materials in a complicated manner. For this reason, there are problems that the number of welds increases, the weight increases, and deformation tends to occur.

[0005] As described above, the aluminum casting material is M
The reason that the fusion welding by IG, TIG, etc. is difficult is that they absorb and solid-dissolve the gas at the time of solidification. Therefore, when fusion welding is performed, the gas forms a blow hole or the gas is ejected. This is because the molten metal is blown off, and a good bonding state cannot be obtained.

[0006] Although there are aluminum casting materials in which gas absorption is eliminated by a casting method using a technique such as vacuum casting, there is a disadvantage that such materials are expensive and inevitably increase the cost. there were.

[0007] On the other hand, aluminum castings are also joined by brazing, but it is still difficult to apply them to structural materials, joints, etc., which are large and require high strength.

As described above, conventionally, there has been a problem in applying the aluminum casting material to the joining technique, so that the advantages of the aluminum casting material cannot be enjoyed.
It has been difficult to produce large-sized, complex-shaped and lightweight structural materials and joints.

The present invention has been made in view of such a technical background, and an object of the present invention is to provide a method for joining an aluminum material which can satisfactorily join an aluminum cast material and aluminum wrought material.

[0010]

To achieve the above object, according to the Invention The method of bonding an aluminum material according to the present invention, Al
Thick joining members made of minium casting and aluminum exhibition
Thin-walled joining members made of stretched materials are arranged in an overlapping state
After that, a probe that rotates at high speed from the thin joint member side
The friction that is brought into contact and the joint is softened by frictional heat and joined
It is characterized by performing a stirring welding method and joining both members .

[0011] The type of the aluminum casting material is not limited, and pure aluminum, Al-Si alloy, Al
-Mg-based alloy, Al-Cu-Si-based alloy, Al-Cu-
JIS for Mg-Si alloy, Al-Mg-Si alloy, etc.
What is necessary is just to select and use suitably from a specification aluminum casting material and other casting materials in relation with a use.

[0012] The type of aluminum wrought material also not be limited, pure aluminum-based, Al-Cu-based (JIS2
000) alloy, Al-Mn (JIS 3000) alloy, Al-Si (JIS 4000) alloy, Al-M
g-based (JIS 5000-based) alloy, Al-Mg-Si-based (JIS 6000-based) alloy, Al-Zn-Mg-based (JI
(S7000 series) alloys or the like may be appropriately selected and used.

[0013] The union Align of the most desirable joining member, Al
Is a mini Umm cast material and the Al-Cu-based alloy Exhibition combination of wrought. This is because, although good joining is difficult by welding such as MIG or the like, according to the present invention, a joint having high joint strength and excellent appearance can be realized.

The friction stir welding method according to the present invention is performed using a probe that rotates at a high speed. FIG. 1 shows an example of a case where welding is performed using a friction stir welding apparatus. In this apparatus, a small-diameter cylindrical probe (11) protrudes and is integrally provided on an end axis of a large-diameter cylindrical support (10), and rotates the support (10) at high speed. As a result, the probe (11) can be simultaneously rotated at a high speed. The probe (11) is formed of a heat-resistant material that can withstand frictional heat generated during welding.

Using the above-described friction stir welding apparatus, friction stir welding is performed, for example, as follows. That is, the two joining members (1) and (2) are arranged at the joining positions. Joint (3) is I than with the match as shown in FIG. 2 (b)
Ku, and Align stacked as shown in FIG. 2 (b). Then, the probe (11) of the friction stir welding apparatus rotating at a high speed is brought into contact with the surface of the joint (3) to soften and plasticize the contact portion, and the probe (11) is further pressed to join the probe (11). It is inserted inside the members (1) and (2).

In the case of a butt joint as shown in FIG. 2A, for reference, the probe (11) is inserted into the butt joint (3) or its vicinity. Then, in this state, the probe (11) is moved along the joining direction of the joint (3). Due to the rotation of the probe (11), around the contact portion with the probe (11),
The joining interfaces of the joining members (1) and (2) are softened and agitated, and the softened and agitated portions are cooled and solidified by the separation caused by the movement of the probe (11). This phenomenon is caused by the probe (1
It is sequentially repeated with the movement of 1), and finally the joining members (1) and (2) are joined at the butt joint.

On the other hand, in the case of the superposition shown in FIG. 2B, the probe (1) is moved over the bonding interface to reach the other member.
It is better to insert 1). Then, the two members (1) can be moved along the overlapping joint (3) at the overlapping joint according to the same principle as described above.
(2) is joined.

A probe insertion hole slightly larger than the outer diameter of the probe (11) may be previously formed in the surface of the joining members (1) and (2) with a drill or the like, and the probe may be inserted into this hole. good.

According to such friction stir welding, the joining members (1) and (2) are joined by softening and stirring in a solid state without melting, as in the case of fusion welding of MIG or the like. In addition, good joining can be realized without causing the disadvantage that the internal gas of the aluminum casting material forms a blow hole or the gas is blown out to blow away the molten metal.

Further, since the joining members (1) and (2) do not melt, the metal structure at or near the joining portion (3) becomes extremely fine as compared with the case of fusion welding, and the elongation and toughness are improved.

[0021]

Next, an embodiment of the present invention will be described.

A butt joint (reference example) as shown in FIG. 2A and a lap joint as shown in FIG.
(Examples) were manufactured as follows, and the tests described later were performed. [But Joint] As shown in FIG. 2A, the width (w1, w2) 100
Two aluminum joining members (1) and (2) having a size of 5 mm × thickness (t) of 5 mm were arranged such that one side in the width direction thereof was abutted. And both joining members were joined by the friction stir welding method or the MIG welding method.

The friction stir welding was performed as follows.
That is, as shown by an arrow, a probe (11) of a friction stir welding apparatus is provided at one end in the length direction of the butt joint (3).
Was rotated in high speed and inserted in the thickness direction of the joining members (1) and (2). The outer diameter of the probe (11) is 8.0m
m, rotation speed is 1600 rpm, insertion depth is 4.9 mm
And Next, the probe (11) is butt-joined along the joint (3) in the longitudinal direction of the joining members (1) and (2) (FIG. 2).
(In the thickness direction of the paper) at a rate of 6.4 cm / min to weld the two aluminum joining members (1) and (2).

On the other hand, in the MIG welding, a welding rod having an outer diameter of 1.6 mm made of JIS 4043 aluminum material is used, and the joining members (1) and (2) are arranged in the longitudinal direction (see FIG. 2 in the paper thickness direction) at a welding speed of 50 cm / min.

In the above, welding was performed by changing the combination of the aluminum joining members (1) and (2) to various types as shown in Table 1. Note that an extruded material was used as the wrought material (joining member 2 of Sample Nos. 6 to 9 in Table 1). [Lap joint] As shown in FIG. 2 (b), width (w1) 110 mm ×
A thick joining member (1) made of an aluminum casting material having a thickness (t1) of 5 mm and a width (w2) of 110 mm × thickness (t)
2) The thin-walled joining members (2) made of a wrought aluminum material of 3 mm were arranged in a state where their one ends in the width direction were overlapped. The overlap margin (L) was 20 mm.

Then, the lap joint (3) was subjected to friction stir welding as follows. That is, as shown by the arrow, the joining member (1) (1) (1) is rotated at a high speed from the thin joining member (2) side at one end of the overlap joining portion (3). It was inserted in the thickness direction of 2). The outer diameter of the probe (11) was 8.0 mm, the rotation speed was 1600 rpm, and the insertion depth was 4.0 mm. Next, the probe (11) is overlapped with 6.4 cm in the length direction (the thickness direction in the drawing of FIG. 2) of the joining portion (3).
The two aluminum joining members (1) and (2) were welded by moving at a speed of / min.

In the above, welding was performed by changing the combination of the aluminum joining members (1) and (2) to various types as shown in Table 1. In addition, the wrought material (sample No. 10-1 of Table 1)
An extruded material was used as the joining member 2) of No. 2.

With respect to the welded product obtained as described above, the appearance of the joint (3) was visually observed, a tensile test was performed, the joint efficiency was measured, and the fracture position was examined. In addition, the joint efficiency was evaluated using the base material strength of the fractured material for different types of joining members. Table 1 shows the results.

[0029]

[Table 1]

As can be seen from the results shown in Table 1, the product of the present invention had a high joint efficiency and was extremely excellent in appearance as compared with the comparative product subjected to MIG welding. In particular, the book
Invention when applied to the junction between the aluminum cast material and Al-Cu-based alloy material (Sample No7) is seen to be achieved an excellent bonding state.

[0031]

According to the present invention, aluminum
Thick joints made of aluminum castings and wrought aluminum
The thin joining members made of
The probe that rotates at high speed from the thin joining member side
Friction stir welding to soften the joint with frictional heat and join
Since the joining method is performed and the two members are joined, soft joining can be performed without melting the joining members. Therefore, unlike in the case of fusion welding of MIG or the like, there is no inconvenience that the internal gas of the aluminum casting material forms a blow hole or the gas is blown to blow out the molten metal. And the wrought aluminum material can be satisfactorily joined, and the range of application of the aluminum casting material to the welded product can be expanded. As a result, the advantages of the aluminum casting material can be sufficiently enjoyed, and a large-sized or complicated-shaped and lightweight welded article such as a structural material or a joint can be provided. Moreover, not only does it not require the use of a filler material, but also because the joining members do not melt, the metal structure at or near the joining portion becomes extremely fine compared to the case of fusion welding, and the elongation and toughness can be improved. it can.

Further, in particular, aluminum cast material was difficult to ensure favorable bonding by welding of MIG such as Al-C
According to the present invention, even for a combination of wrought u-based alloys, a joint having high joint strength and excellent appearance can be realized.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a friction stir welding method.

Figure 2 (a) is a cross sectional view showing an example of a butt joint is a reference example, (b) is a cross sectional view showing an example of the overlapping joint to apply this inventions.

[Explanation of symbols]

 1, 2 ... aluminum joining member 3 ... joining part 11 ... probe

Continuation of the front page (72) Inventor Takenori Hashimoto, 224 Kaiyama-cho, Sakai City Showa Aluminum Co., Ltd. (56) References WO 97/15462 (WO, A1) Masatoshi Enomoto, 2 others, "Plastic flow Joining of Aluminum Alloys ", Proceedings of the 47th Joint Lecture on Plastic Working, 8th Japan Society of Plastic Working, 8th National Diet Library, accepted on October 18, 1996, p. 495-496 (58) Field surveyed (Int. Cl. ⁷ , DB name) B23K 20/12 JICST file (JOIS) WPI / L (QUESTEL)

Claims (1)

(57) [Claims] 1. A thick joint made of an aluminum casting material.
Thin joints made of aluminum and wrought aluminum
After arranging them together, high speed from the thin joint member side
Bring the rotating probe into contact and soften the joint by frictional heat.
Stir welding to join the two parts
A method of joining aluminum materials.