JP3487332B2 - Aluminum structure having excellent surface treatment properties and method for producing the same - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is used not only for structures for construction and civil engineering, structures for vehicles, structures for ships, etc., which are required to have high joint strength, but also for general structures which are not required to have high joint strength. TECHNICAL FIELD The present invention relates to an aluminum-based structure excellent in surface treatability obtained by joining aluminum and / or aluminum alloy (hereinafter referred to as aluminum-based) members and a method for manufacturing the same.

[0002]

2. Description of the Related Art Conventionally, aluminum-based structures for construction and civil engineering, structures for vehicles, structures for ships, etc. have been formed as follows. (1) The aluminum-based members that have been subjected to surface treatment such as painting, alumite treatment, or hairline processing in advance are joined together by a mechanical joining method such as bolt joining. (2) When aluminum-based members are welded by TIG welding and MIG welding, the welding bead is removed by cutting, grinding, etc., and then the coating process is performed. (3) In MIG welding of alumite treated members, the welding wire is A specified in "JIS Z3232".
l Welding is limited to A1000 series aluminum wire with high purity and low Si content, and A5000 series aluminum alloy wire with added Mn, Mg, Cr, Ti and the like and low Si content. This is Si 4.5 ~
A40 such as A4043-WY or A4047-WY containing a large amount of 6.0% or 11.0 to 13.0%, respectively.
This is because the color tone of the weld bead portion subjected to the alumite treatment is greatly different from that of the base material when the 00 series aluminum alloy wire is used.

[0003]

The above method has the following problems. (1) In a method of joining aluminum-based members that have been subjected to surface treatment such as painting, alumite treatment, or hairline processing in advance by using a mechanical joining method such as bolt joining,
It takes manpower and time. (2) Since the filler wire as described above is used in MIG welding, since the composition and structure of the welded portion and the base material portion are different, the color tone of the welded portion and the base material portion is different when anodized. In addition, the amount of welding deformation is large and it may be necessary to correct the deformation after welding, which increases the number of processes,
The manufacturing cost of the structure increases. (3) In TIG welding without using a filler wire, “J
1000 series, 300 specified in ISH 4100 "
Welding of 0 series, 4000 series and 5000 series extruded aluminum materials is not a problem, but 2000 series, 6000 series, 70 series
Weld cracks are likely to occur in 00-based extruded aluminum products. Further, even if welding cracks do not occur, the welded part has a solidified structure, so that the color tone of the welded part and the base metal part are different after the alumite treatment. Further, as in the case of the MIG welding, the amount of welding deformation is large, and it may be necessary to correct the deformation after welding, which increases the number of steps and increases the manufacturing cost of the structure.

In addition to the above method, there is also a method of forming a structure by adhesion using an appropriate adhesive, but this method has no problem in paintability and alumite processability. However, it cannot be applied to aluminum-based structures, which have a problem in joint strength and require strength, such as the above-mentioned construction / civil engineering structures, vehicle structures, and ship structures.

The present invention solves the above-mentioned problems of the prior art and, of course, not only construction / civil engineering structures, vehicle structures, marine structures, etc., which require joint strength, but also general structures which do not require much joint strength. An aluminum-based structure which is also used as a body and has excellent surface treatment properties such as alumite treatment, painting or hairline processing, which is formed by joining aluminum-based members, and has a small amount of joint deformation and excellent landscape, and a method for producing the same. Is an issue.

[0006]

In order to solve the above-mentioned problems, the present invention comprises a plurality of aluminum and / or aluminum alloy members to be anodized, painted or hairline-bonded on the outer surface, and surface-treated. The aluminum-based structure having excellent properties is joined by friction stir welding from the back side of the outer surface and has a joining portion having excellent surface treatment properties.

In the present invention, the surface roughness of the friction stir welding backing which contacts the outer surface of the aluminum-based structure excellent in surface treatment is Rmax 6.3 S or less, R
It is desirable to configure so that the maximum is 0.8 S or more.

In the present invention, the aluminum-based structure having excellent surface treatment property has a surface roughness of the friction stir welding backing contacting the outer surface of more than Rmax 6.3S and not more than Rmax 25S. In some cases, it is desirable that the joint surface of the outer surface in contact with the backing be hairline-processed.

In order to solve the above-mentioned problems, the present invention comprises an aluminum-based structure having excellent surface treatability, which is formed by joining a plurality of aluminum and / or aluminum alloy members to be anodized, painted or hairline-processed on the outer surface. The method for producing a body is configured so as to be joined by friction stir welding from the back side of the outer surface.

In the present invention, the surface roughness of the friction stir welding backing contacting the outer surface is Rmax 6.3 according to the above method for producing an aluminum-based structure having excellent surface treatment property.
It is desirable to configure so that it is S or less and Rmax is 0.8S or more.

In the present invention, the surface roughness of the friction stir welding backing contacting the outer surface is Rmax according to the above method for producing an aluminum-based structure having excellent surface treatment property.
It is desirable that the surface of the joined portion of the outer surface in contact with the backing be subjected to hairline processing when it exceeds 6.3 S and Rmax is 25 S or less.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the accompanying drawings and specific embodiments.

1. Example 1 The following experiment was conducted as an example according to claims 1 and 2 of the present invention and a comparative example thereof. That is, a test piece of 300 mm in length, 100 mm in width, and 3 mm in thickness, "JIS
Aluminum alloy plate material 5083 specified in "H 4000"
H34 and aluminum extruded profile 6N01-T5 specified in “JIS H 4100” are used to perform butt joining using the following three joining methods and butt joint processing, and then alumite Processed.

(1) The surface roughness of the outer surface to be treated is R
A backing material of max 6.3 S is applied, friction stir welding (hereinafter sometimes abbreviated as FSW) is performed from the back side of the outer surface, and the joining portion of the outer surface after joining is not processed. (2) MIG welding was performed using aluminum alloy filler wire A5356-WY specified in "JIS Z 3232", the welding bead was removed by cutting, and the surface roughness was finished to be Rmax 6.3S. . (3) TIG welding was performed without using a filler wire or a filler rod, the welding bead was removed by cutting, and the surface roughness was finished to be Rmax 6.3S.

The friction stir welding in the above item (1) is performed as follows. That is, as shown in the cross-sectional view of FIG. 1, the end faces of the pair of materials 1 and 2 to be joined are brought into contact with each other so that the outer surfaces 1 os and 2 os to be surface-treated after joining are lower surfaces, but the abutting portion 3 is formed, and the backing 4 is arranged so that the surface 4us contacts the outer surfaces 1os and 2os around the abutting portion 3. Then, from the rear surface 1rs, 2rs side of the pair of materials to be welded 1, 2 is projected downward from the center of the concave surface of the friction stir welding probe main body 5 or the flat circular bottom surface 5bs coaxially with the rotation axis of the probe main body 5. The stirring pin 6 is rotated and pushed into the pair of materials 1 and 2 to be joined at the abutting portion, and the probe body 5 is pressed in a direction indicated by an arrow Fp with a predetermined pressing force Fp (kgf), so that the probe body While pressing the concave or flat circular bottom surface 5bs of 5 onto the back surfaces 1rs, 2rs of the materials to be joined 1, 2 while rotating the probe body in the direction of the arrow (r), the joining line (butt 3)
1 in the direction perpendicular to the paper surface of FIG. 1 and the friction heat generated around the stirring pin 6 or below the concave surface of the probe body 5 or the flat circular bottom surface 5bs causes the butting. The part 3 is solid-phase bonded.

Visual observation of the presence or absence of welding cracks in the test piece that has been joined, joined portion processed, and anodized as described above, measurement of the amount of joining (welding) deformation, and visual inspection of the color tone difference between the base material and the joined portion after the anodizing treatment. Observations were made and the results are shown in Table 1 below. The amount of deformation of welding (welding) was measured as follows. That is, as shown in the perspective view of FIG. 2, a joining material 7 obtained by joining a pair of materials 1 and 2 to be joined along a joining line 3tl is used as a platen having a flat surface such that its warp direction is the upper surface. 8 on both sides of the joining material 7 in the longitudinal direction (direction of the joining method line 3tl), and a total of four positions that divide the longitudinal direction into three equal parts, in the width direction of the joining material 7. the total two places at both ends, at the position 7pm the end face of the bonding material 7 of 4 × 2 = 8 points in total sum, the height from the surface of the bonding material 7 to the top surface of the base plate 8 is measured by a dial gauge 9 Using one of the measured values at these eight locations as a reference value, the amount of welding deformation was determined by the amount of change (difference) in the other measured values with respect to the reference value.

[0017]

[Table 1]

The following can be said from Table 1 above. (1) The difference in color tone between the base material and the joint after the alumite treatment was not seen in the member that was friction stir welded, but in the MIG welded member using the above filler wire A5356-WY, a slight difference in color tone was observed. I was seen. TI without filler rod
In the G welding member, the aluminum alloy 5083-H3 is used.
The difference in color tone was very slight both in the case of using 4 as the base material and in the case of using 6N01-T5 as the base material. (2) Weld cracks are caused by the aluminum alloy 6N01-T.
It occurred in the TIG welded member having 5 as a base material, but did not occur in other parts. (3) The amount of welding (welding) deformation is 1 for friction stir welding members.
Although it was as small as mm or less, it was as large as 3 mm or more for the MIG welded member and the TIG welded member.

From the above, a member having a surface roughness of Rmax 6.3S applied to the outer surface to be anodized and friction stir welding from the back side of the outer surface is a member to be joined to the base material after the alumite treatment. Since there is no difference in color tone, there is no weld cracking, and the amount of joint (welding) deformation is small, it is an aluminum-based structure that has excellent surface treatment properties and excellent scenery including other points of view. It can be seen that the method of friction stir welding from the back side of the outer surface subjected to alumite treatment is a method suitable for producing an aluminum-based structure which is excellent in surface treatment property and is also excellent in landscape including other appearances.

2. Example 2 The following experiment was conducted as another example according to claims 1 and 2 of the present invention and its comparative example. That is, a test piece using the same two kinds of aluminum alloy materials as the one shown in Example 1 was used, and
Butt-joining using the same three types of joining methods as described in (3) to (3), the butt-joining portion was processed, and then the coating process was performed. In addition, after painting, degreasing the joint material,
Spray coating was performed using a commercially available color spray paint.

Visual observation of the presence or absence of weld cracks in the test pieces that have been joined, joined portion processed, and painted as described above, and joined (welded)
The amount of deformation was measured, the difference in color tone between the base material and the joint portion after the coating treatment was visually observed, and the adhesion test of the coating film was performed. The results are shown in Table 2 below. In addition, the adhesion test of the coating film is "JIS H 02
01 ”(“ JIS H 8602 ”,“ JIS K 5400 ”).

[0022]

[Table 2]

From Table 2 above, the following can be said. (1) No difference in color tone between the base material after coating and the coating film on the joint was observed between the three types of joining / joint processing methods. (2) In the adhesion test result of the coating film, almost no difference was observed depending on the joining method and the joining portion processing method. (3) Weld cracks were not observed except for the TIG welded 6N01-T5 alloy. (4) The amount of deformation of welding (welding) is 1 for friction stir welding members.
Although it was as small as mm or less, it was as large as 3 mm or more for the MIG welded member and the TIG welded member.

From the above, it can be seen that, in the case of the member which was friction stir welded from the back side of the outer surface to be coated, there was no difference in color tone between the base metal and the joint after the coating treatment, the adhesion of the coating film was good, and welding cracks were observed. It is an aluminum-based structure that has excellent surface treatment properties because it has a small amount of welding (welding) deformation, and has excellent scenery including other appearances. Also, friction stir from the back side of the outer surface to be coated. It can be seen that the joining method is a method suitable for producing an aluminum-based structure having excellent surface treatment properties, a small amount of joining (welding) deformation, and other aspects, and having excellent scenery.

3. Example 3 The following experiment was conducted as an example according to claims 1 and 2 of the present invention and a comparative example thereof. That is, as the test piece, the aluminum alloy plate material 6N01-T5 having a length of 300 mm, a width of 100 mm and a thickness of 3 mm was used. As shown in Examples 1 and 2 above, MIG welding and TI
Since welding cracks occurred in G welding, the amount of welding (welding) deformation was larger than that in friction stir welding, and color differences were observed in the alumite treatment, the butt welding method was limited to friction stir welding. When the aluminum alloy member to be anodized on the outer surface is friction stir welded from the back side of the outer surface, the surface roughness of the friction stir welding backing contacting the outer surface is divided into three stages, The outer surface to which the surface of the backing was transferred was subjected to an alumite treatment, and the relationship between the surface roughness of the friction stir welding backing and the appearance after the alumite treatment (color tone difference between the base material and the joint) was investigated. At this time, the case where the outer surface (on the backing contact side) was hairline-processed before the alumite treatment and the case where the hairline was not processed were separately investigated. The survey results are shown in Table 3 below.

[0026]

[Table 3]

The following can be said from Table 3 above. (1) If the surface roughness of the backing is Rmax 6.3S or less,
With or without hairline processing on the contact surface of the backing, there was no difference in color tone between the base material and the joint, and a good appearance was obtained. (2) When the surface roughness of the backing was Rmax 25S, there was no difference in color tone between the base material portion and the joint portion when hairline processing was performed, and a good appearance was obtained. However, in the case of no hairline processing, the difference in color tone between the base material portion and the joint portion was clearly recognized because the surface roughness of the base material portion and the joint portion were different, and the base material portion and the joint portion were clearly discriminated.

From the above, a member friction-stir-welded from the back side of the outer surface to be alumite-treated is provided if the surface roughness of the friction stir-welding backing contacting the outer surface is Rmax 6.3S or less. With or without hairline processing on the contact surface, there is no difference in color tone between the base material and the joint, and good scenery can be obtained including other viewpoints (for example, the amount of deformation of the material to be joined). Suitable for use as an aluminum-based structure having excellent processability, and having a surface roughness of Rmax of 6.3 S or less for the friction stir welding backing when friction stir welding is performed from the back side of the outer surface of the aluminum member for surface treatment. It can be seen that the method used is suitable as a method for producing an aluminum-based structure having excellent surface treatment properties.

The surface roughness of the backing for friction stir welding is
Rmax 0.8S or more is sufficient. If the surface roughness of the backing is in the range of Rmax 6.3S to Rmax 0.8S, there is no difference in color tone between the base material and the joint after the alumite treatment, and the surface roughness is less than Rmax 0.8S. If this is done, the surface processing cost of the backing will increase, and the surface roughness of the backing will rapidly increase as the number of times of use increases, and soon the surface roughness will become Rmax 0.8S or more. Because.

Further, in the member which is friction stir welded from the back side of the alumite treated outer surface, the surface roughness of the friction stir welding backing which contacts the outer surface exceeds Rmax 6.3S, and R
If max25S or less, there is no difference in color tone between the base material and the joint as long as the outer surface joint is hairline-processed, and a good view including other viewpoints (for example, the amount of deformation of the jointed material) Suitable as an aluminum-based structure having excellent surface treatment property, and the surface roughness of the backing for friction-stir welding is Rmax 6 when friction-stir welding from the back side of the outer surface of the aluminum-based member to be surface-treated. Over 3S, Rmax
In the case of 25 S or less, it can be seen that the method of hairline-processing the contact portion of the backing is suitable as a method for producing an aluminum-based structure having excellent surface treatment properties.

Although the embodiments of the present invention have been described above based on specific examples, the present invention is not limited to the above-mentioned embodiments, and within the scope of the gist of the invention, It includes other embodiments.

Next, the basic operation of the embodiment of the present invention described above will be described below. That is, in the appearance of the friction stir welded aluminum-based member, ripple-like marks are observed on the surface in contact with the bottom surface of the friction stir welding rotary probe during welding, but the back surface is very smooth.
Further, the inside of the joint has a very fine structure, and the crystal grain size is smaller than that of the base material. Also, there are no welding defects such as those found in fusion welding such as MIG welding and TIG welding. As shown in Tables 1 and 3, a plurality of aluminum and / or aluminum alloy members whose outer surface is anodized are anodized on the outer surface of the member that is friction stir welded from the back side of the outer surface. If processed,
A material having no difference in color tone between the base material portion and the joint portion was obtained. The reason for this is that since the filler wire is not used, the components of the base metal part and the joint part are the same, and the same processed structure (recrystallized structure) can be obtained as the metal structure although there is a difference in grain size. It is considered that the structure of the joint is fine because it is a solid-state joining process in which hot working is performed under plastic strain. Another reason is that there are no defects in the joint. As shown in Table 2, for the same reason as the alumite treatment in the coating process as well, since the coating base treatment property is excellent also in the bonding part, the aluminum-based structure having excellent adhesion of the coating film also in the bonding part. It is thought that the body is obtained.

Further, in the case of joining a casting, a wrought material and castings together, in fusion welding such as MIG welding or TIG welding, the quality of the joint is greatly affected by the quality of the casting of the material. That is, MIG is used for castings containing hydrogen and other gases.
When fusion welding such as welding and TIG welding is performed, a large amount of porosity is generated inside the weld due to the release of gas when the molten metal is cooled and solidified. On the other hand, since friction stir welding is a solid phase process, defects such as porosity do not occur at the joint. As a result, an aluminum-based structure having excellent alumite processability and paintability can be obtained.

[0034]

EFFECTS OF THE INVENTION According to the aluminum-based structure having excellent surface treatment property and the method for producing the same, the following excellent effects are exhibited. (1) Compared with a case where aluminum-based members that have been surface-treated in advance are joined together by a mechanical joining method such as bolt joining, it takes less time and labor. (2) Compared with the case of fusion welding such as MIG welding or TIG welding, there are no defects such as welding cracks and porosity, and there is little joining (welding deformation), and when anodized,
There is no color difference between the base metal part and the joint part, it has excellent surface treatment properties, and it is easy to form an aluminum-based structure with good scenery including other viewpoints {for example, the amount of joint (welding) deformation}. Is. (3) Aluminum-based structures that require higher bonding strength than the method of forming structures by adhesion using an adhesive, for example, structures for construction and civil engineering, structures for vehicles, structures for ships, etc. An aluminum-based structure that can be applied and is also used as a general structure that does not require much bonding strength can be easily obtained.

[Brief description of drawings]

[1] for producing the aluminum-based structure which is excellent in surface treatment of the present invention according to claim 1, applied to the production of aluminum-based structure which is excellent in surface treatment of the present invention according to claim 2 It is a schematic sectional drawing which shows the friction stir welding method.

FIG. 2 is a perspective view showing a method for measuring the amount of deformation of a joining (welding) material after butt joining (welding).

[Explanation of symbols]

1, 2 Materials to be joined 3 Butt 4 backing 5 probe body 5bs concave or flat bottom 6 stirring pins 7 Bonding material 8 surface plate 9 dial gauge

─────────────────────────────────────────────────── ─── Continuation of the front page (56) Reference JP-A-9-309164 (JP, A) JP-A-10-202374 (JP, A) JP-A-10-52770 (JP, A) (58) Field (Int.Cl. ⁷ , DB name) B23K 20/12

Claims (2)

(57) [Claims] 1. An aluminum-based structure having excellent surface treatability, which is formed by joining a plurality of aluminum and / or aluminum alloy members to be anodized, painted or hairlined to the outer surface, and the back side of the outer surface. From the surface roughness of the backing for friction stir welding that is in contact with the outer surface is less than R max 3.0 S and R max 0.8 S or more. Aluminum-based structure with excellent surface treatment characteristics. 2. An aluminum-based material having excellent surface treatability, which is obtained by joining a plurality of aluminum and / or aluminum alloy members to be anodized, painted or hairlined on the outer surface by friction stir welding from the back side of the outer surface. A method of manufacturing a structure, wherein the surface roughness of a friction stir welding backing contacting the outer surface is less than R max 3.0 S , R m
A method for producing an aluminum-based structure having excellent surface treatability, which is characterized by having ax of 0.8 S or more.