JP2000246430A - Joining method for aluminum alloy member - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a joining method for an aluminum alloy member, by which solder does not attach except a joining part and ultrasonic vibrations are easily transmitted to a base material. SOLUTION: After immersing a vibration plate 9 with an ultrasonic horn 8 mounted into a solder bath 10, the vibration plate 9 is pulled up from the solder bath 10, and melted solder 14 is allowed to remain on the vibration plate 9. An aluminum alloy member 1a is placed on the vibration plate 9 on which this melted solder 14 has remained. Next, by generating ultrasonic waves by operating the ultrasonic horn 8, and by applying the ultrasonic waves to the above aluminum alloy member 1a through the vibration plate 9, solder layers are formed on the joining surfaces 2a of the aluminum alloy member 1a. After that, these joining surfaces 2a are butted, and while applying a pressure to them, ultrasonic joining is performed to them.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for joining aluminum alloy members by an ultrasonic soldering method.

[0002]

2. Description of the Related Art Conventionally, when soldering aluminum alloys to each other, an ultrasonic soldering method as shown in FIGS. These figures show aluminum alloy members 101a and 101b having a substantially U-shaped cross section.
2 shows a procedure for joining the end faces 102a and 102b to each other. First, as shown in FIG. 12, end surfaces 102a and 102b of aluminum alloy members 101a and 101b are machined to form smooth surfaces. Next, as shown in FIG. 13, the aluminum alloy member 101a is
a is placed on the bottom surface 112 such that the a contacts the diaphragm 109. In this state, diaphragm 109 and aluminum alloy member 101a are immersed in solder bath 110. An ultrasonic horn 108 is attached to the diaphragm 109,
By operating the ultrasonic horn 108, ultrasonic waves are applied to the aluminum alloy member 101a via the vibration plate 109 to form a solder layer 115a as shown in FIG. Also for the aluminum alloy member 101b,
The same processing is performed.

[0003] The bottom surface 112 of the diaphragm 109 is the solder bath surface 1.
In order to be immersed downward from 10a, the solder layer 1 is also provided on the aluminum alloy members 101a and 101b on portions other than the end surfaces 102a and 102b, that is, on the side surfaces 103a and 103b.
15a and 115b adhere. These end faces 10
The aluminum alloy members 101a and 101b are vertically overlapped in a state where the aluminum alloy members 101a and 101b are in contact with each other, and as shown in FIG.
The ultrasonic horn 120 is placed on “a”. In this state,
While heating the vicinity 121 of the joint portion between the aluminum alloy members 101a and 101b with a burner or the like, simultaneously applying ultrasonic waves to join the two members 101a and 101b and then cooling them, a joined product as shown in FIG. 12
3 is obtained.

[0004]

However, the above-mentioned conventional joining method has the following problems. (1) Since the ends of the aluminum alloy members 101a and 101b are immersed in the solder bath 110, the joining surfaces 102
Solder also adhered to the side surfaces 103a and 103b other than the side surfaces a and 102b, which was not preferable in appearance. There is a method of performing ultrasonic soldering after applying a mold, and a method of physically removing attached solder after performing ultrasonic soldering. However, all of these have led to increased costs.

(2) Since the vibration plate 109 is immersed in the solder bath 110, the ultrasonic vibration oscillated from the ultrasonic horn 108 is weakened when transmitted to the vibration plate 109. Therefore, it is difficult to form sound solder layers 115a and 115b in a portion covered with a strong oxide film, such as a casting surface of an aluminum alloy casting. As described above, there is a method of removing the oxide film by performing machining or the like on the casting surface of the aluminum alloy casting, but this method is costly. Further, the method of forming a solder layer on the casting surface by increasing the ultrasonic output is not preferable from the viewpoint of appearance because the solder easily adheres to portions other than the joining surfaces 102a and 102b.

An object of the present invention is to solve the above-mentioned problems, and to provide a method of joining aluminum alloy members, which can minimize solder adhesion to a portion other than a joining surface and can efficiently apply ultrasonic vibration to an object to be processed. And

[0007]

According to the present invention, in order to achieve the above object, a diaphragm having an ultrasonic horn attached thereto is immersed in a solder bath, and then the diaphragm is pulled up from the solder bath and melted into the diaphragm. The solder is left, the aluminum alloy member is placed on the diaphragm where the molten solder remains, and then the ultrasonic horn is operated to generate ultrasonic waves,
By applying ultrasonic waves to the aluminum alloy member through a diaphragm, a solder layer is formed on the joint surface of the aluminum alloy member, and then the joined surfaces are joined to each other by applying ultrasonic waves and applying pressure. Is the way.
When applying ultrasonic waves to the aluminum alloy member, the above-mentioned diaphragm is not immersed in the solder bath, so that the molten solder on the diaphragm can be vibrated efficiently, and the vibration force of the diaphragm is strong. Become. This makes it possible to join the aluminum alloy members to each other even if the joining surface is not a machined surface but a casting surface. The thickness of the molten solder on the diaphragm lifted from the solder bath is preferably about 0.5 to 3 mm.

[0008] In one embodiment of the present invention, after the vibrating plate to which the ultrasonic horn is attached is immersed in a solder bath, the vibrating plate is held near the bath surface of the solder bath and molten solder is placed on the vibrating plate. The aluminum alloy member is placed on the diaphragm where the molten solder remains, and then the ultrasonic horn is operated to generate ultrasonic waves, and ultrasonic waves are applied to the aluminum alloy member via the vibration plate. By applying the solder, a solder layer is formed on the joining surface of the aluminum alloy member, and then the joining surfaces are butted together and joined by applying ultrasonic waves and applying pressure. By holding the vibrating plate near the bath surface of the solder bath, the vibrating plate is not cooled, so that the molten solder on the vibrating plate hardly solidifies. Therefore, a solder layer is easily formed on the joint surface of the aluminum alloy member. Further, according to the present invention, it is possible to perform joining after die-casting an aluminum alloy casting having an undercut portion such as a closed deck cylinder block in a divided state.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a method for joining aluminum alloy members according to the present invention will be described in detail based on the illustrated embodiment. The bonding method of the aluminum alloy member according to the present embodiment is to raise the diaphragm immersed in the solder bath immediately before solder coating, and at this time, by utilizing the molten solder thinly left on the diaphragm,
The aim is to prevent solder from adhering to portions other than the joint portion of the aluminum alloy member, and to form a solder layer reliably even when the joint surface is not a machined surface but a casting surface.

First, a description will be given of a material, an apparatus, and the like used in a bonding method according to an embodiment of the present invention. [Material to be Treated] As the material to be treated used in the joining method of the present embodiment, an aluminum alloy member, particularly, a wrought material or a cast material which is aluminum and its alloys specified in JIS, etc., is suitable. , ADC12 material, A606
1, A5052, AC4C and the like. Although the shape is not particularly limited, the present invention can be applied to, for example, a case where end surfaces 2a and 2b of members 1a and 1b having a substantially U-shaped cross section as shown in FIG. [Solder] In addition to solder AH-Z95A (Zn-5 wt% Al) and pure Zn for aluminum material specified in JIS, the solder used in the bonding method of the present embodiment is
Zn-Sn-based, Zn-Cd-based, Sn-Pb-based and the like can be mentioned, and Zn-Al-based zinc solder is desirable from the viewpoint of strength, melting point and corrosion resistance.

[Ultrasonic Soldering Apparatus] As shown in FIGS. 2 to 4, an ultrasonic soldering apparatus 6 used in the bonding method of the present embodiment includes an ultrasonic vibrator 7 for generating ultrasonic waves, An ultrasonic horn 8 for amplifying the ultrasonic waves generated by the ultrasonic vibrator 7, a diaphragm 9 attached to the ultrasonic horn 8 and having a substantially hat-shaped cross section, and a tank 11 containing a solder bath 10. It has. Further, the diaphragm 9
Is to make the central part of one smooth flat
2 and the end 13 is attached to the ultrasonic horn 8. Next, the operation of the ultrasonic soldering device will be described. First, the ultrasonic vibration generated by operating the vibrator is transmitted to the diaphragm with the amplitude increased by the ultrasonic horn. Next, since the member to be processed is placed on the diaphragm, the amplified ultrasonic vibration is transmitted to the member. At this time, since the diaphragm is not immersed in the solder bath and is arranged in the air, the diaphragm vibrates freely, and the vibration force becomes stronger than in the conventional case. For this reason, even if there is an obstacle such as an oxide film on the member surface, a solder layer can be formed on the member surface.

Next, a joining method according to the present embodiment will be described for each procedure. (1) Manufacturing Step of Material First, as shown in FIG. 1, two aluminum alloy members 1a and 1b each having a substantially U-shaped cross section are prepared, and their end surfaces 2a and 2b are used as joining surfaces. These joining surfaces 2a, 2b
May be formed on a smooth surface by machining or may be left as it is on the casting surface. (2) Vibrating Plate Preheating Step As shown in FIG. 2, the bottom surface 12 of the vibrating plate 9 is immersed in a solder bath 10 accommodated in a tank 11, and is sufficiently preheated.
The preheating temperature is slightly different depending on the type of the aluminum alloy members 1a and 1b and the solder, but it is generally preferable that the preheating temperature is equal to or higher than the melting point of the solder + 20 ° C. The temperature of the solder bath 10 is preferably about the melting point of the solder plus about 20 ° C to 70 ° C.

(3) Step of Pulling Up Vibrating Plate As shown in FIG. 3, the vibrating plate 9 that has been immersed is pulled up from the solder bath 10, and a thin molten solder 14 is left on the bottom surface 12 of the vibrating plate 10. The thickness of the molten solder 14 is
0.5 mm to 3 mm is preferred. (4) Solder Layer Forming Step Before the molten solder 14 remaining on the bottom surface 12 of the diaphragm 9 solidifies, as shown in FIG.
Is placed on the bottom surface 12 and the ultrasonic horn 8 is operated,
By applying ultrasonic waves to the aluminum alloy members 1a and 1b via the diaphragm 9, a solder layer 15a is formed on the joint surface 2a of the aluminum alloy member 1a as shown in FIG. This ultrasonic wave has an oscillation frequency of 20 kHz, for example.
Before and after z, the oscillator output is preferably 150 to 1000 W, and the ultrasonic wave application time is preferably 3 to 10 seconds. The solder layer 15b is formed on the joint surface 2b of the aluminum alloy member 1b in the same procedure.

(5) Ultrasonic bonding step After the formation of the solder layers 15a, 15b, the bonding surface 2 of the aluminum alloy members 1a, 1b
a and 2b are brought into contact with each other. In this state, as shown in FIG. 6, the ultrasonic horn 20 is placed on the upper part of the aluminum alloy member 1a disposed above, and ultrasonic waves are applied while applying pressure to both members 1a and 1b. The two members 1a and 1b are joined. Regarding the conditions for applying the ultrasonic wave, the frequency is about 20 kHz and the output is 150 to 10
00W and the application time are preferably 0.5 seconds to 10 seconds.
In addition, the joining surfaces 2a of the aluminum alloy members 1a, 1b,
When the solder layers 15a and 15b formed on the 2b are solidified, as shown in FIG. 7, the vicinity 21 of the joint between the two members 1a and 1b is formed by using a conventional heating means 22 such as a gas burner or high-frequency induction heating. While heating, both members 1a, 1b are pressurized and ultrasonic waves are applied, so that both members 1a, 1b are heated.
b can be joined. The heating temperature is preferably + 20 ° C. to 70 ° C. of the melting point of the solder, and the heating time is preferably a time immediately after the application of ultrasonic waves after the melting of the solder. (6) Cooling step Finally, the joined members 1a and 1b are cooled to complete the joined product 23 as shown in FIG.

Next, the present invention will be described based on specific embodiments.

[Embodiment 1] First, as shown in FIG. 1, aluminum alloy members 1a and 1b made of AC4B and having a substantially U-shaped section are prepared.
The joining surfaces 2a and 2b, which are the end surfaces of b, were formed into smooth surfaces by machining. On the other hand, as shown in FIG. 2, a bath temperature of 4 is applied to the bottom surface 12 of the diaphragm 9 constituting the ultrasonic soldering device 6.
It was immersed in a solder bath 10 at 20 ° C. for 30 minutes. The composition of this solder was Zn-5 wt% Al, and its melting point was 382 ° C. The aluminum alloy members 1a and 1b were preheated at 380 ° C. for 30 minutes. Next, FIG.
As shown in (1), the diaphragm 9 was lifted upward, and a thin molten solder 14 was left on the bottom surface 12 of the diaphragm 9. The thickness of the molten solder 14 was 2 mm as a result of the measurement.

Thereafter, as shown in FIG. 4, the aluminum alloy members 1a and 1b were placed on the bottom surface 12 of the diaphragm 9, and in this state, ultrasonic waves were simultaneously applied to both members 1a and 1b. By this application, as shown in FIG. 5, the solder layers 15a and 15b were formed with a thickness of 50 μm on the joining surfaces 2a and 2b of the aluminum alloy members 1a and 1b. The ultrasonic wave has an oscillation frequency of 19 kHz and an oscillator output of 35 kHz.
0 W and application time was 5 seconds. Then, as shown in FIG. 6, immediately after the formation of the solder layer 15, the joining surfaces 2a and 2b of the aluminum alloy members 1a and 1b before the solidification of the solder were superimposed to form a substantially rectangular shape. In this state, as shown in FIG. 7, without heating the aluminum alloy members 1a and 1b, the ultrasonic horn 20 is placed on the aluminum alloy members 1a and 1b disposed on the upper side.
Ultrasonic waves were applied while applying pressure for bonding. The ultrasonic wave was applied at an oscillation frequency of 19 kHz, an oscillator output of 350 W, and an ultrasonic wave application time of 5 seconds. As a result, as shown in FIG. 8, the aluminum alloy members 1a, 1
Except for the joining surfaces 2a and 2b of b, there was almost no adhesion of solder.

[Embodiment 2] Aluminum alloy members 1a,
1b is made of ADC12, and bonding surfaces 2a, 2
Example 1 except that b was not a machined surface but a casting surface
Aluminum alloy members 1a, 1
Example 2 in which b was joined was performed.

Comparative Example A comparative example in which an aluminum alloy member was joined by a conventional method to Examples 1 and 2 described above will be described. As shown in FIG.
Aluminum alloy members 101a and 101b having a material of ADC12 and a casting surface having a joint surface were prepared, and the aluminum alloy members 101a and 101b were preheated at 380 ° C. for 30 minutes. On the other hand, as shown in FIG.
Solder bath 1 with Zn-5wt% Al at 2 ° C and bath temperature 420 ° C
The diaphragm 109 and the aluminum alloy members 101a and 101b were immersed in the solder bath 110. In this state, an ultrasonic wave was applied to both the aluminum alloy members 101a and 101b at an oscillation frequency of 19 kHz, an oscillator output of 350 W, and an ultrasonic wave application time of 5 seconds. By this soldering, as shown in FIG. 14, solder layers 115a and 115b were formed on the side surfaces 103a and 103b other than the joining surfaces 102a and 102b of the aluminum alloy members 101a and 101b. Immediately after the formation of the solder layers 115a and 115b, as shown in FIG. 15, the joining surfaces 102a and 102b of the aluminum alloy members 101a and 101b are superimposed on each other. 35
0 W, an ultrasonic wave for 5 seconds was applied,
6 was obtained. At this time, no heating was performed.

As a result of a tensile test of the joined product obtained in Example 2 and the comparative example, the joined product 123 of the comparative example was broken at the joint, but the joined product 23 obtained in Example 2 was broken.
Was cut with a base material. From this, it was found that the bonding method according to the present invention had higher bonding strength. Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various modifications can be made based on the technical idea of the present invention. For example, as the material of the members 1a and 1b, in addition to aluminum, structural steel or structural piping that can be pressed, bent, forged, and welded, such as SS400 or SPC, can be used. It is also possible to join with structural steel. However, in this case, it is necessary to apply copper plating to the joint surface of the structural steel as pretreatment.

The shape of the bottom surface 12 of the diaphragm 9 is shown in FIG.
It does not have to be a substantially flat surface as shown in FIG. For example, as shown in FIG. 9, when a convex portion 29 is formed below the members 1a and 1b, a stepped portion 30 or a concave portion 30 which is recessed downward on the bottom surface 12 of the diaphragm 9 according to the shape of the convex portion. A hole may be formed. Further, as shown in FIG. 10, the diaphragm 9 may be immersed in the solder bath 10 for the thickness of the diaphragm 9 without completely lifting the diaphragm 9 from the solder bath 10. That is, the height of the upper surface 12a of the bottom surface 12 of the diaphragm 9 and the height of the bath surface 10a of the solder bath 10 may be substantially equal to each other. The molten solder 14 on the diaphragm 9 is harder to solidify than when the molten solder 14 is pulled up. In order to prevent the solder from being oxidized, a pipe 31 for flowing a non-oxidizing gas such as Ar, N ₂ , CO ₂ or the like may be provided on or near the vibration plate 9 as shown in FIG. That is, the diaphragm 9 is preheated while the non-oxidizing gas is flowing, and the diaphragm 9 is kept flowing while the non-oxidizing gas is flowing.
Is lifted, the preheated aluminum alloy member 1a is placed on the bottom surface 12, and ultrasonic waves are applied. As a result, the oxidation of the solder can be suppressed, the solder coating defects are reduced, and the reliability is improved.

[0021]

According to the present invention, the amount of solder attached to portions other than the joints is reduced, and the cost is reduced. Further, since a small amount of molten solder of the diaphragm is used, the ultrasonic vibration can be easily transmitted to the base material, and a solder layer can be formed on the casting surface.

[Brief description of the drawings]

FIG. 1 is a sectional view of an aluminum alloy member used in a joining method according to the present invention.

FIG. 2 is a cross-sectional view showing a state in which a diaphragm is immersed in the bonding method according to the present invention.

FIG. 3 is a cross-sectional view showing a state where the diaphragm is pulled up in the bonding method according to the present invention.

FIG. 4 is a cross-sectional view showing a state in which a solder layer is formed on a bonding surface of an aluminum alloy member by a bonding method according to the present invention.

FIG. 5 is a cross-sectional view showing an aluminum alloy member having a solder layer formed on a bonding surface by a bonding method according to the present invention.

FIG. 6 is a cross-sectional view showing a state in which the aluminum alloy members are ultrasonically bonded to each other in the bonding method according to the present invention.

FIG. 7 is a cross-sectional view showing a state in which the aluminum alloy members are ultrasonically bonded to each other while being heated in the bonding method according to the present invention.

FIG. 8 is a cross-sectional view showing a completed aluminum alloy member joined by the joining method according to the present invention.

FIG. 9 is a cross-sectional view illustrating an ultrasonic apparatus having a diaphragm according to another embodiment.

FIG. 10 is a cross-sectional view illustrating a method of pulling up a diaphragm according to another embodiment.

FIG. 11 is a cross-sectional view showing a bonding method according to another embodiment.

FIG. 12 is a sectional view of an aluminum alloy member used in a conventional joining method.

FIG. 13 is a cross-sectional view showing a step of forming a solder layer at a joint of an aluminum alloy member in a conventional joining method.

FIG. 14 is a cross-sectional view of an aluminum alloy member in which a solder layer is formed at a bonding portion in a conventional bonding method.

FIG. 15 is a cross-sectional view showing a state in which both members are ultrasonically bonded by conventional ultrasonic bonding.

FIG. 16 is a cross-sectional view showing a completed aluminum alloy member joined by a conventional joining method.

[Explanation of symbols]

 1a, 1b Aluminum alloy member 2a, 2b End face 6 Ultrasonic soldering device 7 Ultrasonic vibrator 8 Ultrasonic horn 9 Vibrating plate 10 Solder bath 11 Tank 12 Bottom 13 End 14 Melting solder 15 Solder layer 20 Ultrasonic horn 21 Joining Near the part 22 Heating means 23 Joined product 29 Convex part 30 Step part 31 Pipe

Claims (2)

[Claims] After immersing a diaphragm attached with an ultrasonic horn in a solder bath, the diaphragm is pulled out of the solder bath to leave molten solder on the diaphragm, and aluminum is added to the diaphragm where the molten solder remains. Place the alloy member, then actuate the ultrasonic horn to generate ultrasonic waves,
By applying ultrasonic waves to the aluminum alloy member through a diaphragm, a solder layer is formed on the joint surface of the aluminum alloy member, and then the joined surfaces are joined to each other by applying ultrasonic waves and applying pressure. A method for joining aluminum alloy members. 2. After immersing the diaphragm with the ultrasonic horn in a solder bath, the diaphragm is held near the bath surface of the solder bath so that molten solder remains on the diaphragm. The aluminum alloy member is placed on the remaining diaphragm, and then the ultrasonic horn is operated to generate ultrasonic waves, and ultrasonic waves are applied to the aluminum alloy member through the diaphragm, thereby forming the aluminum alloy member. A method for joining aluminum alloy members, comprising: forming a solder layer on a joint surface of an alloy member; and then joining the joined surfaces by applying ultrasonic waves and applying pressure.