JP4227886B2 - Surface treatment method of metal plate material for friction stir welding, surface-treated metal plate material, and friction stir welding method - Google Patents

Description

The present invention is a friction stir welding (FSW: Friction Stir) of a metal plate material such as an aluminum (including aluminum alloy) material and a magnesium compound applied to a moving body that moves at high speed such as an aircraft, a rocket, a high-speed vehicle, and a high-speed ship. the surface treatment method of a metal plate material for friction stir welding for joining the Welding), relates to surface-treated metal sheet, and friction stir welding how.

For structural members such as ships, aluminum alloys are often used from the viewpoint of weight reduction. As a method for laminating and joining such aluminum alloy structural members, arc welding such as TIG and MIG is generally used.
However, in the case of an aircraft or the like, since the structural member is a thin plate, the vicinity of the joint portion is softened by welding heat and the strength is lowered, and there is a risk that thermal distortion may occur and assembly may be difficult.

For this reason, in aircraft and the like, a method of joining thin plates such as aluminum alloy with rivets is frequently used in order to avoid deformation of the metal plate due to heat, deflection, or change in the metal structure. However, in the rivet joining, the laminated thin plates are not welded to each other and are still in an independent state.
Therefore, the rivet hole becomes a stress concentration source, and there is a problem that fatigue damage may occur from the rivet hole when the aircraft is used for a long time. For this reason, inspections are regularly performed, and there is a problem that maintenance costs increase.

Therefore, in recent years, a friction stir welding method (FSW method) has been proposed in which stacked metal plates are joined by friction.
In the friction stir welding method, a tool that rotates at high speed is pressed against two stacked aluminum thin plates, and the thin plates are locally softened by frictional heat and mixed without melting. Friction stir welding is faster than rivet bonding and enables production costs to be reduced, and is particularly effective when joining thin aluminum alloy plates such as aircraft members.

As a method of overlapping and joining two aluminum alloy plates by the friction stir welding method, those shown in FIGS. 7 and 8 have been proposed.
The upper workpiece 50 is positioned so as to overlap with the lower workpiece 51, and as shown in FIG. A strip 53 of corrosion resistant material is attached to the outer surface 54 of the upper workpiece 50 so that the material covers a predetermined weld zone that will be plasticized during the welding operation.

Next, a friction stir welding operation is performed and the rotary stir pin (probe) 12 extends completely through the thickness of the upper workpiece 50 and partially through the thickness of the lower workpiece 51. As a result, the welded zone 55 is made from the outer surface 54 through the upper workpiece 50 and at least partially through the thickness of the lower workpiece 51 as shown in FIG. 7B. The
The corrosion-resistant strip 53 is sheared by the shoulder of the tool (friction stir welding tool) 10 and is metallurgically joined to the outer surface of the welding zone 55 to form a corrosion-resistant zone 57 that covers the outer surface of the joint.

FIG. 8 shows a modification of the above lap welding method.
Workpieces 50 and 51 are overlaid, and an overlap joint is defined therebetween. A layer 56 of corrosion resistant material is interposed between the workpieces at the lap joint.
A friction stir welding process is performed to form a lap joint weld in the region of the workpiece with a layer 56 of corrosion resistant material. The rotating stirring pin (probe) 12 plasticizes the workpiece metal and creates a plastic flow of the layer 56 of corrosion resistant material in the area of the weld. Two sheets of 7063 aluminum alloy having a thickness of 0.063 inches are overlaid and a friction stir welding operation is performed with a non-alloy aluminum cladding layer interposed between the sheets prior to welding. A continuous layer of non-alloyed aluminum remains at the joint, preventing the corrosive material from acting on the joint and causing corrosion.
This welding method is disclosed to be effective, for example, so that moisture taken in between the workpieces does not contact the welded joint and cause corrosion. (For example, Patent Document 1)

JP 2000-61664 A (paragraphs [0027], [0028], FIG. 8, FIG. 9)

In the method in which two aluminum alloy plates are overlapped and joined by the above-described conventional friction stir welding method, the corrosion resistance is improved by sandwiching a corrosion resistant material, welding, melting and integrating them. However, depending on the additive element, the corrosion resistance is improved, but the strength characteristics are lowered, and it is difficult to form a partially thin film.
In general, aluminum plate materials for aircraft and the like are anodized (anodized) in the manufacturing process.

And in the above-mentioned conventional friction stir welding method, since an anodized film is shaved and friction stir welding is performed, there is a possibility that moisture permeates around the welded portion due to capillary action and the aluminum plate material is corroded.
In addition, it is necessary to apply a rust preventive paint such as a primer after welding, but it is difficult to apply the rust preventive paint to the entire surface of the overlapped part other than the welded part, and the rust preventive treatment cannot be performed sufficiently. There is.

The present invention has been made in order to solve such a conventional problem, and an aluminum plate material that has been treated with an oxide film is used as it is, and a rust preventive paint (primer) is applied before superposition. by joining by friction stir welding after the surface treatment method of a metal plate material for friction stir welding that does not decrease the strength with obtaining the corrosion protection, the surface-treated metal sheet for friction stir welding, and friction stir welding it is an object of the present invention to provide a mETHODS.

The present invention has been made in order to solve the above-mentioned problems, and the first means is a method for treating the surface of a metal plate for friction stir welding in a metal plate having an oxide film formed on the surface thereof . In applying a primer containing a resin, a curing agent, and a solvent, the dry weight of the powder or flakes of a substance having a higher thermal conductivity than that of the primer is 7 to 45% in the dry primer. as it is characterized in that mixed 5-30 wt% to the primer.

Incidentally, the metal plate material, aluminum, aluminum alloy, or Ru or a metal plate der of magnesium alloy.

Furthermore, flour powder also Sakhalin piece of thermally conductive material having a high than the primer, Ru aluminum, aluminum alloys, magnesium, either in powder powder addition Sakhalin piece of magnesium alloy or carbon Ah.

According to a second means of the present invention, in the surface treatment method for a metal plate material for friction stir welding of the first means, the oxide film is an anodized film.

The third means of the present invention is characterized in that, in the surface treatment method of a metal plate material for friction stir welding of the first or second means, the outer diameter of the powder or flake is 10 μm or less.

According to a fourth means of the present invention, in the surface treatment method for a metal plate material for friction stir welding according to any one of the first to third means, the primer is an epoxy resin.

According to a fifth means of the present invention, in the surface treatment method for a metal plate material for friction stir welding according to any one of the first to fourth means, the primer comprises an epoxy resin and a curing agent for a polyamide resin or a modified polyamine resin. It is characterized by being cured by two-component room temperature drying consisting of

Sixth means of the present invention, the surface treatment method of a metal plate material for friction stir welding of any means the first to 5, the Powder The Sakhalin pieces entrained primer and the Powder or a is It is characterized in that it is applied separately from a primer that does not contain any flakes .

The seventh means of the present invention is a surface-treated metal plate for friction stir welding, wherein the metal plate is made of aluminum, aluminum alloy, or magnesium alloy, the oxide film formed on the surface of the metal plate, aluminum is applied to the surface of the oxide film, an aluminum alloy, magnesium, magnesium alloy or flour powder either flour powder addition Sakhalin pieces are mixed 7-45 dry weight percent of carbon addition Sakhalin piece input Ri primer layer, and a primer layer the powder the Sakhalin piece is applied to the surface of the oxide film is not mixed, the powder the Sakhalin piece input Ri primer layer and the powder the Sakhalin piece is not mixed It is characterized in that the primer layer is separately applied.

The eighth means of the present invention is characterized in that, in the surface-treated metal sheet for friction stir welding of the seventh means, the oxide film is an anodized film.

Friction stir welding method of the ninth aspect of the present invention, superimposing the surface-treated metal sheet for friction stir welding of the seventh means, press the friction stir welding tool which rotates against it the surface treatment was obtained superimposed A metal plate material is joined, and the friction stir welding tool is advanced along the joining portion to perform friction stir welding.

A tenth means of the present invention is characterized in that, in the friction stir welding method of the ninth means, the oxide film is an anodized film.

According to an eleventh means of the present invention, in the friction stir welding method of the ninth or tenth means, the friction stir welding tool is advanced along the joining portion, and then the friction stir welding tool is moved to the joining portion. It is characterized by reversing along.

According to a twelfth means of the present invention, in the friction stir welding method of the ninth or tenth means, after the friction stir welding tool is advanced along the joining portion, the rotation direction of the friction stir welding tool is changed. It reverses and it is made to advance again along the said junction part.

According to a thirteenth means of the present invention, in the friction stir welding method of the ninth or tenth means, two friction stir welding tools that are reverse to each other are used to advance along the joining portion to perform friction stir welding. It is a feature.

According to the surface treatment method of a metal plate material for friction stir junction as described above for the first aspect of the present invention, since the surface of the metal sheet is covered with oxide film, the conveyance of the metal sheet, templating, cutting Even at times, the surface will not corrode.
Further, since the primer is applied on the oxide film, the work of polishing the oxide film as in the conventional case can be omitted.
Furthermore, flour powder of heat conductive material having a high addition of Sakhalin piece 5 to 30 wt% (7-45% by dry weight) since the mixed, in a short time at the primary with the strength of the primer film can be secured Friction heat can be transmitted to melt and flow out the primer of the friction stir weld.
Metal sheet surface-treated as described above, by bonding with the friction stir welding, the frictional heat is transferred powder powder thermally conductive material having a high mixed in during the primer also through the Sakhalin pieces primer Then, the primer at the joining portion is easily melted and discharged out of the friction stir welding portion without remaining at the joining portion due to the applied pressure at the time of joining.
And the friction stir welding part can be excellent in corrosion resistance and strength.

The first means of the present invention can be applied aluminum, aluminum alloy, or a thin plate of any one of metal plate made of magnesium alloy.

Furthermore, the first means of the present invention, flour powder thermally conductive sufficiently larger material than the primer also as a Sakhalin piece, aluminum, aluminum alloys, magnesium, or powder powder or a magnesium alloy or carbon because it uses Sakhalin pieces, these powders late addition Sakhalin pieces during friction stir welding, after melting the primer, it is possible to dissolve into the metal sheet.

According to the surface treatment method of the friction stir welding metal plate material as the second means of the present invention, in addition to the effects of the first means, the oxide film is made an anodic oxide film, whereby the friction stir welding is performed. Even if it does, optimal joining can be performed.

According to the surface treatment method of the metal plate material for friction stir welding as the third means of the present invention, in addition to the effect of the first or second means, the outer diameter of the powder or flakes is changed to the primer coating film. By setting the thickness to 10 μm or less, the primer coating surface can be made smooth.

According to the surface treatment method for a friction stir welding metal plate as a fourth means of the present invention, in addition to the effects of any one of the first to third means, the primer may employ an epoxy resin. it can.

According to the surface treatment method of a metal plate material for friction stir welding according to a fifth aspect of the present invention, in addition to the effect of any means of the first to fourth, the primer is an epoxy resin a polyamide resin or altered polyamine It is possible to employ a two-pack type curing agent that is made of a resin curing agent and dried at room temperature.

According to a sixth surface treatment method for a metal plate material for friction stir welding as a means of the present invention, in addition to the effect of the means in the first to fifth, the Powder The Sakhalin pieces to portions Friction stir welding applying contaminating primer and by applying a primer that does not mixed with the powder the Sakhalin piece in a portion not bonded, the primer in the portion other than the joint portion during the friction stir welding does not melt, pressing member or the like Will not adhere.

According to the surface-treated metal sheet for friction stir welding of a seventh aspect of the present invention, the thermal conductivity of large aluminum, aluminum alloys, magnesium, either flour powder addition Sakhalin piece of magnesium alloy or carbon 7 Since 45 % by dry weight is mixed, the strength of the primer film can be ensured, and frictional heat can be transmitted to the primer in a short time by friction stir welding.
And the primer of a junction part melt | dissolves easily and is discharged | emitted out of a friction stir junction part, without remaining in a junction part.
These powders late addition Sakhalin piece, after melting the primer, is discharged to the outside together with the primer.
Moreover, parts in friction stir joining by applying a primer mixed with the Powder The Sakhalin piece, the portion not bonded by applying a primer that does not mixed with the Powder The Sakhalin piece, during friction stir welding Since the primer other than the joining portion does not melt, the pressing member or the like does not adhere.

According to the surface-treated metal plate material for friction stir welding as the eighth means of the present invention, in addition to the effects of the seventh means, the oxide film is an anodized film, thereby performing friction stir welding. In addition, it is possible to obtain a surface-treated metal plate that can be optimally joined.

According to the friction stir welding method as the ninth means of the present invention, the surface of the metal plate made of aluminum, aluminum alloy, or magnesium alloy is covered with an oxide film, so The surface does not corrode even during cutting and cutting.
Further, since the primer is applied on the oxide film, the work of polishing the oxide film as in the conventional case can be omitted.
Furthermore, since the mixed powder powder addition Sakhalin piece of thermally conductive material having a high 7-45% by dry weight, can transfer frictional heat to the primary in a short time with the intensity of the primer layer can be ensured .
In this way, friction stir welding with excellent corrosion resistance and strength can be performed.

According to the friction stir welding method as the tenth means of the present invention, in addition to the effect of the ninth means, an optimum friction stir welding can be performed by using the oxide film as an anodic oxide film.

According to the friction stir welding method as the eleventh and twelfth means of the present invention, in addition to the effects of the ninth or tenth means, the friction stir welding tool generates on the retreating side of the friction stir welding part depending on the rotation direction of the friction stir welding tool. The remaining oxide film can be eliminated.

According to the friction stir welding method as the thirteenth means of the present invention, in addition to the effects of the ninth or tenth means, the working time of the friction stir welding can be further shortened .

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a perspective view showing a joining state by a friction stir welding method according to the first embodiment of the present invention, and FIG. 2 is a partially enlarged view of FIG.
FIG. 3 is a detailed cross-sectional view of the joint according to the first embodiment of the present invention.
FIG. 4 is a view showing a micrograph of a cross section of the joint according to the first embodiment of the present invention, and FIG. 5 is an explanatory view schematically showing FIG.
FIG. 6 is a perspective view showing a primer application state to the structural member according to the first embodiment of the present invention.

As shown in FIGS. 1 and 2, for example, a skin (outer plate) 1, a stringer (longitudinal aggregate) 2, a frame (lateral aggregate) 3, etc. in a moving body that navigates, operates, and moves at high speed such as an aircraft. As the structural member, it is necessary to adopt a member that is lightweight and has excellent strength and corrosion resistance, and a metal plate made of aluminum or aluminum alloy having a thickness of about 2 to 4 mm is used. A skin 1 as a metal plate is an outer plate of a movable body, and is reinforced by a stringer 2 as a metal plate extending in the front-rear direction and a frame 3 as a ring-shaped metal plate across the metal plate.
The stringer 2 and the frame 3 are friction stir welded to the skin 1 by the friction stir welding tool 10.
In addition, although illustration is abbreviate | omitted, the skin 1 is similarly overlap | superposed and the edge part is overlap | superposed and friction stir welding is carried out.

As shown in FIG. 2, the friction stir welding tool 10 includes a columnar rotor 11 and a probe (pin) 12 projecting from the tip of the rotor 11 on the rotation shaft. Is rotated at high speed. The probe 12 has a cylindrical shape or at least a tip having a conical or hemispherical shape.
The axial length of the probe 12 is longer than the thickness of the member (for example, the stringer 2) with which the friction stir welding tool 10 comes into contact, and more than the total thickness of the two overlapped members (stringer 2 and skin 1). It is set to be shorter.
A flat disc-shaped shoulder 13 is formed on the lower surface of the rotor 11.
In the present embodiment, since the plate thickness of the skin 1, the stringer 2 and the frame 3 is about 2 mm, the length of the probe 12 is about 3 mm, the diameter is about 5 mm, and the diameter of the shoulder 13 is about 12 mm. The size of the friction stir welding tool 10 is appropriately selected according to the thickness of the friction stir welding.

  As shown in FIG. 2, the stringer 2 and the skin 1 are joined in a clockwise direction with the rotor 11 and the probe 12 at high speed with the stringer 2 (or the frame 3) superimposed on the upper surface of the skin 1. While rotating to Z, the rotor 11 and the probe 12 are pressed with a predetermined force Y to melt the stringer 2 and the skin 1 by frictional heat, and the probe 12 is inserted into the stringer 2 and the skin 1. The insertion is performed until the shoulder 13 of the rotor 11 contacts the stringer 2.

At this time, by rotating the rotor 11 at a high speed, frictional heat is generated by sliding between the probe 12 and the shoulder 13 and the stringer 2, and the material of the stringer 2 and the skin 1 near the contact of the friction stir welding tool 10. Is softened and agitated and plastically flowed to form a friction stir weld 4 having no voids.
As a result, the skin 1 and the stringer 2 are joined.

Then, the probe 12 is moved in the longitudinal direction X along the stringer 2 with the probe 12 inserted. As the probe 12 moves, the stringer 2 and the skin 1 in the traveling direction are softened and stirred one after another and fluidized. The softened and fluidized stringer 2 and the skin 1 receive the traveling pressure of the probe 12 and wrap around backward in the traveling direction so as to fill the passage groove of the probe 12.
In the case of FIG. 2, most of the softened and fluidized material passes around the right side of the traveling direction X and goes around the probe 12. After that, the stringer 2 and the skin 1 that have been softened and fluidized and circulated to the rear of the probe 12 lose the frictional heat rapidly and are cooled and solidified to form the friction stir joint 4.

  Further, as shown in FIG. 1, in the present embodiment, two friction stir welding tools 10 are connected in the front-rear direction of the traveling direction, and are rotated at high speeds in opposite directions. Thus, by rotating at high speed in opposite directions, the friction stir welding part 4 without left and right unevenness can be formed.

Note that it is not always necessary to connect two of them. When performing the joining work with one friction stir welding tool 10, after moving in the traveling direction X, it is moved in the opposite direction to the traveling direction X while rotating at high speed in the same direction Z, and reciprocated. Also good.
Furthermore, after the friction stir welding operation is once performed, the friction stir welding tool 10 may be rotated at a high speed in the opposite direction, and the same place may be moved again in the traveling direction X to perform the friction stir welding operation. .

  By doing in this way, the advance side (the same direction as the direction of the friction stir welding tool and the direction of rotation) generated by the rotational direction Z and the direction of travel X of the friction stir welding tool 10, the retreating side (the direction of travel and rotation) Differences in softening, fluidization, and solidification on the opposite side), that is, no anodized film remains on the retreating side, and the friction stir weld 4 having no left-right unevenness can be formed.

  In this way, after all the stringers 2 are bonded to the back surface of the skin 1, the frame 3 is also bonded to the skin 1 in the same manner. The friction stir welding part 4 is heated to 400 to 500 ° C., but the time during which the temperature is maintained at 400 ° C. or more in each part is as short as 10 seconds or less. Therefore, the skin 1, the stringer 2 and the frame 3 are There is no thermal deformation.

  Next, based on FIG. 3, the metal plate surface treatment method of the aluminum plate material according to the first embodiment of the present invention, the paint used in the friction stir welding method, and the friction stir welding method will be described in detail.

First, the surface treatment in the case of an aluminum plate as the metal plate will be described. As this metal plate, a general 2000 series or 7000 series aluminum sheet is used.
The skin 1, the stringer 2, and the frame 3 are formed by cutting a thin metal plate material of aluminum or aluminum alloy having a thickness of 2 mm into predetermined dimensions and bending it.

Both surfaces of skin 1 and stringer 2 (frame 3), which are thin metal plates of aluminum, are usually anodized (anodized film, alumina layer) 20 by anodizing (anodized) with a film thickness of about 1 to 5 μm. It is covered with and is strong against impact and corrosion.
In addition, since the heat resistance is low in the chemical film treatment and the corrosion resistance is somewhat lowered when the friction stir welding is performed, the anodic oxide film is superior.
The anodic oxide film has a high heat resistance temperature, and even after friction stir welding, the anodic oxide film (alumina layer) remains on the surface and has corrosion resistance.

By leaving the anodic oxide film 20 in this way, the adhesion of a coating film such as a primer, which will be described later, can be improved, and the metal plate material can be conveyed and processed without corroding the surface.
If the anodic oxide film 20 is not polished, the anodic oxide film remains in the friction stir welding portion 4 and the strength is lowered. Therefore, in the conventional friction stir welding method, the surface of the metal plate material is polished to produce an aluminum background. In this embodiment, the anodized film 20 is not polished.

Moreover, as a metal plate material, it is not limited to aluminum, An aluminum alloy, a magnesium alloy, etc. are employable.
The oxide film is optimally an anodic oxide film, but is not limited to this, and a chemical film treated film can also be used.

Then, the surface of the anodized film 20, in order to improve the adhesion between the base material and top coating of metal plate, as a base coating, with a good thermal conductivity powder powder or in locations particularly performing friction stir welding Apply primer mixed with flakes .
Note that, in a conventional overlap joint by friction stir welding, if the joint is subjected to a rust preventive treatment such as a primer, it is taken into the primer friction stir joint 4 and the strength of the joint deteriorates due to this. Therefore, friction stir welding was performed without applying a primer or the like to the surface.
That is, the conventional primers good thermal conductivity powder powder addition Sakhalin piece is not mixed is not melted in a short heating by heat conduction is poor friction stir welding for a resin.
For this reason, the resin is caught in the joint and remains in the joint, resulting in a defect and a reduction in strength.

In this embodiment, since a resin such as a primer is melted by heating in a short time, fine powders of aluminum, aluminum alloy, copper, copper alloy, magnesium alloy, carbon, etc. that have no problem even if mixed into the resin and have good thermal conductivity end the mixing Sakhalin pieces primer.
Fine powder The Sakhalin pieces mixed is aluminum is optimal, carbon does not corrode also appropriate.

The fine powder addition Sakhalin piece of good aluminum or the like having the heat conductivity, mixed in a proportion of 5 to 30 wt% in the primer (epoxy containing resin, solvent, curing agent, etc.).
If it is less than 5%, the amount of conduction of frictional heat is reduced and the resin is not sufficiently melted. On the other hand, if the amount is more than 30%, the amount of the resin is reduced, so that the rust prevention effect is lowered and the coating film is cracked.
Furthermore, when the primer dries, the strength of the coating film decreases.

The outer diameter of aluminum or other powder or flakes mixed in the primer is 10 μm or less so that the coating thickness when the primer is dried is 20-30 μm, so that the powder or flakes are not exposed on the surface. Is desirable.
If the thickness is more than the dry coating thickness, the surface of the coating after drying the primer will not be smooth, and there is a possibility that the gap will become large when two metal sheets are overlapped and friction stir welding will not be performed sufficiently. is there.

As the resin for the primer, an epoxy resin that melts by heating in a short time is optimal, but a urethane resin, a polyester resin, and a phenol resin can also be adopted as other than the epoxy resin. As the curing agent, a polyamide resin or a modified polyamine resin is used. And the two-component primer which consists of a hardening | curing agent of an epoxy resin and a polyamide resin or a modified polyamine resin hardens | cures by normal temperature drying after application | coating.
Incidentally, in place of the powdered late addition Sakhalin piece input Ri primer coating layer 22, a good thermal conductivity powder powder addition Sakhalin piece input Ri adhesive may be applied to the joint. This adhesive can be used that is softened by heat at the time of joining and is excluded from the friction stir weld 4 at the time of joining.

Then, portions facing the stringer 2 of the surface of the skin 1 (or frame 3), the above-mentioned film thickness primers fine powder also Sakhalin pieces are mixed is applied such as aluminum is about 20~30μm powder powder the Sakhalin piece input Ri coating layer 22 is formed.
The portion other than the above-mentioned skin 1 prevent softening during friction stir welding, in order to prevent welding of the backing member 14, the usual primer fine powder also Sakhalin piece is not mixed is coated thickness A primer coating layer 21 having a thickness of about 10 μm is formed.

An anodized film 20 having a thickness of about 0.5 to 5 μm is also formed on the inner and outer surfaces of the stringer 2 (or the frame 3).
Then, portions facing the skin 1 of the stringer 2, the fine powder also thickness primers Sakhalin piece is mixed is applied the end flour of about 10μm The Sakhalin piece input Ri coating layer of aluminum or the like described above 22 is formed.
In the stringer 2, the primer is not applied to the portion where the probe 12 and the shoulder 13 of the friction stir welding tool 10 are in contact during the friction stir welding.
The portion other than the above stringer 2, in order to prevent Pushing material 15 and welded to prevent softening during the friction stir welding, with conventional primers fine powder also Sakhalin piece is not mixed is applied, the thickness A primer coating layer 21 having a thickness of about 20 to 30 μm is formed.
Incidentally, flour powder addition Sakhalin piece input Ri primer, it is desirable that was applied to both surfaces facing the skin 1 and stringer 2.

Anodized film 20 as described above, the primer coating layer 21, superimposed powder powder addition Sakhalin piece skin 1 and stringer 2 where entrance Ri primer coating layer 22 is formed, is placed on the backing member 14.
Then, the stringer 2 is pressed with the pressing member 15 to bring the skin 1 and the stringer 2 into close contact with each other.
Thereafter, the friction stir welding tool 10 is pressed from above the stringer 2 and rotated at a high speed, and the friction stir welding tool 10 is moved on the stringer 2 along the joining line while melting the stringer 2 and the skin 1. .
At this time, the portion where the friction stir welding is performed is heated to 400 to 500 ° C., but the time during which the temperature is maintained at 400 ° C. or higher in each part is as short as 10 seconds or less. With the movement, the friction stir weld 4 is immediately cooled and solidified.

A part of the primer coating layer 21 fine powder also Sakhalin piece is not mixed well and heated to 500 ° C., the heating time is carbonized is longer, the temperature in the individual sites in this embodiment is 400 Since the time for maintaining the temperature at 10 ° C. or higher is 10 seconds or shorter, it melts and flows but does not cause carbonization.
In this way, the skin 1 and the stringer 2 are melted and joined.

A photomicrograph of the cross section of the joined portion is shown in FIG. FIG. 5 is a schematic view of the micrograph of FIG.
4 and 5 are similar in shape even when an outer plate of an aircraft or the like manufactured by the friction stir welding method of the present embodiment is analyzed.
The right part of FIG. 5 illustrates the advance side when only one friction stir tool 10 is used and friction stir welding is performed only once.
When the friction stir welding tool 10 is changed in the rotation direction and stirred again, when reciprocating in the same rotation direction, when two friction stir welding tools 10 are lined up and stirred, the right side of FIG. 5 is the same as the left side. It becomes the shape of.

As shown in FIG. 5, no primer or anodized film remains on the advance side (the left side in FIG. 5) of the friction stir welding portion 4.
The anodic oxide film is not alloyed but is dispersed in the friction stir weld 4.
On the other hand, on the retreating side (the right side in FIG. 5) of the friction stir welding portion 4, since the anodized material is difficult to join, the remaining anodic oxide film layer 5 remains in the vicinity of the overlapping portion of the skin 1 and the stringer 2. is doing.
As described above, the anodized film remaining layer 5 is formed by connecting two friction stir welding tools 10 in the front-rear direction of the advancing direction and rotating them at high speed in opposite directions, or by one friction stir welding tool. 10 is reciprocated while rotating at high speed in the same direction, or once the friction stir welding operation is performed, the friction stir welding tool 10 is rotated at high speed in the opposite direction and the same place is friction stir welded again. .
In this way, the bonding strength of the friction stir welding portion 4 is ensured.

As a comparative example, the joining state of a conventional one is shown in FIGS.
As shown in the figure, when the friction stir welding is performed without mixing the powder of aluminum or the like into the primer, a large number of large gaps 62 are generated in the joint 60, and a large gap is formed around the joint 60. 61 layers of remaining primer remain

In addition, a very thin layer having a width of about 3 to 5 mm is formed on the adjacent side 6 of the boundary on the advance side of the friction stir weld 4.
At the joint adjacent side 6, most of the primer is discharged, and only the anodic oxide film 20 (not shown in FIG. 5) remains.

In the vicinity of the joint 7 at the boundary of the outer side of the joint adjacent side 6 (this part is exaggerated in FIG. 5), the anodized film 20 and the primer coating layer 21 (parts) are formed on the surfaces of the skin 1 and the stringer 2. specifically, the primer coating layer 22 Ri oN flour powder addition Sakhalin piece) is previously applied, is formed.

The primer coating layer 22 flour powder was applied to the friction stir joining portion 4 Drying The Sakhalin piece input Ri is beyond the softening point was melted by frictional heat during the friction stir welding, and flows out the outflow primer 23 Thus, the skin 1 around the joint portion 7 and the primer coating layer 21 of the stringer 2 are melted and integrated. Note that the primer coating layer 21 and the outflow primer 23 that this integrated flour powder also Sakhalin pieces such as aluminum remaining.

  In addition, although the friction stir welding part 4 is heated to 400-500 degreeC, since the time which temperature hold | maintains 400 degreeC or more in each site | part is as short as 10 seconds or less, the heat conduction of the junction periphery 7 is bad. The normal primer coating layer 21 does not melt.

  Further, a part of the outflow primer 23 protrudes from the overlapping end portion of the skin 1 and the stringer 2 and is solidified.

When the aluminum surface is polished and overlapped and friction stir welded as in the past, a gap remains in the overlapped portion other than the friction stir welded portion, and even if a primer is applied after joining, the overlapped portion The gap cannot be completely filled.
Then, moisture penetrates due to capillary action and the aluminum corrodes.
On the other hand, in the present embodiment, the gap in the overlapping portion of the skin 1 and the stringer 2 is filled with the outflow primer 23 that has melted and flowed out from the friction stir welding portion 4, so that the gap does not remain, and the watertightness Is ensured and moisture does not enter, and the joint surface can be protected.

Next, with reference to FIG. 6, a skin 1 forming a part of an outer surface material manufactured in the manufacturing process of an aircraft or the like will be described.
A thin metal plate made of aluminum or aluminum alloy having a thickness of 2 mm is cut and bent into a predetermined dimension as shown in FIG. The anodic oxide film 20 is formed in advance.
The inner surface of the skin 1, the portion for joining the stringer 2 and frame 3, high flour powder addition Sakhalin piece input Ri primer thermal conductivity is applied, the grid-like powder powder addition Sakhalin piece ON Ri primer A coating layer 22a is formed. The dried primer is mixed with 7-45% of a powder having high thermal conductivity such as aluminum or a flake.
Furthermore, the other portions of the inner surface of the skin 1 primer powder powder addition Sakhalin piece is not mixed is applied, the primer coating layer 21 is formed.

In the case of manufacturing an aircraft body such as an aircraft by superposing and joining the end portions of the skin 1, the skins 1 are also friction stir welded to each other, so that heat conduction is also applied to the outer surface of one end portion of the skin 1. and sexual high powder powder addition Sakhalin piece input Ri primer is applied, flour powder addition Sakhalin piece input Ri primer coating layer 22b is formed.

  As mentioned above, although embodiment of this invention was described, it cannot be overemphasized that this invention is not limited to said embodiment, A various change may be added to the specific structure within the scope of the present invention. .

It is a perspective view which shows the joining state by the friction stir welding method which concerns on 1st Embodiment of this invention. It is the elements on larger scale of FIG. It is detail sectional drawing before joining which concerns on 1st Embodiment of this invention. It is a figure which shows the microscope picture of the cross section of the junction part which concerns on 1st Embodiment of this invention. FIG. 5 is an explanatory diagram schematically showing FIG. 4. It is a perspective view which shows the primer application condition to the skin which concerns on 1st Embodiment of this invention. (A) is sectional drawing which shows the overlap joint part before welding of a conventional thing, (B) is sectional drawing which shows the overlap joint part after welding. FIG. 6 is a cross-sectional view of a lap joint where there is a layer of corrosion resistant material introduced between the workpieces that overlap prior to conventional welding. It is a figure which shows the microscope picture of the cross section of the junction part when joining after applying the conventional primer. FIG. 10 is an explanatory diagram schematically showing FIG. 9.

Explanation of symbols

1 Skin (outer plate)
2 Stringer (longitudinal aggregate)
3 frame (lateral aggregate)
DESCRIPTION OF SYMBOLS 4 Friction stir welding part 5 Anodic oxide film residual layer 6 Joining part adjacent side 7 Joining part periphery 10 Friction stir welding tool 11 Rotor 12 Probe 13 Shoulder 14 Backing material 15 Pushing material 20 Anodic oxidation film 21 Primer coating layer 22 powder powder The Sakhalin piece input Ri primer coating layer 22a powder The Sakhalin piece input Ri primer coating layer (back surface)
22b Powder The Sakhalin piece input Ri primer coating layer (surface)
23 Outflow primer 50 Work piece 51 Work piece 52 Overlap joint 53 Strip of corrosion resistant material 54 Outer surface 55 Weld zone (friction stir joint)
56 Corrosion Resistant Material Layer 57 Corrosion Resistant Zone 60 Joint 61 Remaining Primer 62 Notch

Claims (13)

On the metal plate material made of aluminum, aluminum alloy, or magnesium alloy with an oxide film formed on the surface ,
In applying a primer containing resin, curing agent and solvent ,
Aluminum, aluminum alloys, magnesium, either a powder or flake of the magnesium alloy or carbon, so that the dry weight of the powder or flaky in dry primer is 7-45%, 5-30 wt above primer %. A surface treatment method for a metal plate material for friction stir welding, characterized in that the composition is mixed. 2. The surface treatment method for a metal plate material for friction stir welding according to claim 1, wherein the oxide film is an anodized film. The surface treatment method for a metal plate material for friction stir welding according to claim 1 or 2, wherein the powder or the flake has an outer diameter of 10 µm or less. 4. The surface treatment method for a metal plate material for friction stir welding according to claim 1, wherein the primer is an epoxy resin. The metal for friction stir welding according to any one of claims 1 to 4, wherein the primer is cured by a two-component room temperature drying comprising an epoxy resin and a curing agent of a polyamide resin or a modified polyamine resin. Surface treatment method for plate material. The surface treatment method for a metal plate material for friction stir welding according to any one of claims 1 to 5, wherein the primer mixed with the powder or the flakes and the primer not mixed with the powder or the flakes are separately applied. . Metal plate material made of aluminum, aluminum alloy, or magnesium alloy, oxide film formed on the surface of the metal plate material, and any of aluminum, aluminum alloy, magnesium, magnesium alloy or carbon coated on the surface of the oxide film A powder layer containing 7 to 45% by dry weight of powder or flakes or a primer layer containing flakes, and a primer layer coated on the surface of the oxide film and not mixed with the powder or flakes, A surface-treated metal sheet for friction stir welding, wherein a primer layer containing powder or flakes and a primer layer not mixed with the powder or flakes are separately coated. The surface-treated metal sheet for friction stir welding according to claim 7, wherein the oxide film is an anodized film. The surface-treated metal plate material for friction stir welding according to claim 7 is overlaid, the rotating friction stir welding tool is pressed against each other, the overlaid surface-treated metal plate material is joined, and the friction stir welding tool is A friction stir welding method, wherein the friction stir welding is performed by advancing along the joining portion. The friction stir welding method according to claim 9, wherein the oxide film is an anodized film. The friction stir welding method according to claim 9 or 10, wherein the friction stir welding tool is moved forward along the joining portion after the friction stir welding tool is advanced along the joining portion. 11. The friction stir welding tool is advanced along the joining portion, and then the direction of rotation of the friction stir welding tool is reversed and advanced again along the joining portion. The friction stir welding method described in 1. The friction stir welding method according to claim 9 or 10, wherein two friction stir welding tools that are reverse to each other are used to advance along the joining portion.