JP3460518B2 - Joining method of aluminum member and iron member - Google Patents

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a method of joining an aluminum member and an iron member by soldering using ultrasonic waves. INDUSTRIAL APPLICABILITY The present invention can be applied to joining intake manifolds for four-wheel vehicles, water outlet pipes, and the like.

[0002]

2. Description of the Related Art As a method of joining an aluminum member and a dissimilar metal member, the surface of the dissimilar metal member is preliminarily subjected to a plating treatment such as copper plating, as described in JP-A-5-185217. After that, a method of performing soldering is known. However, since this method includes a plating process, there are many steps and the cost is high. That is, the plating treatment comprises steps of degreasing, washing with water, pickling, washing with water, electrolysis, washing with water and drying, which requires many steps and is time-consuming.

FIG. 4 shows a plating process, which is a pretreatment process before joining an iron pipe, which is a component of the composite intake manifold, and an iron surge tank, and further before joining the aluminum flange. Figure 4 (a)
Shows the case where the whole part is plated, and (b) shows the case where only the joint with the aluminum flange is plated.

In FIG. 4 (a), a plating solution 9 in a plating tank 8 is immersed with a joint of an iron pipe 2 and an iron surge tank 3. When the entire iron member is plated in this way, it becomes difficult to prevent rust after joining and the plating solution is wasted. In FIG. 4B, masking 10 is applied to the surface of the joined steel pipe 2 and the iron surge tank 3 except for the joined portion with the aluminum flange. When the plating is applied only to the joint portion as described above, the rust prevention treatment after the joint with the aluminum flange is not hindered, but the cost required for the masking is added and the cost is increased.

On the other hand, even if soldering is performed by using ultrasonic waves without applying plating, the oxide film on the surface of the iron member hinders soldering and cannot be joined. Even if joining is performed by brazing without plating, the aluminum-based brazing material has a high brazing temperature, so that the aluminum member is melted.

[0006]

SUMMARY OF THE INVENTION An object of the present invention is to provide a method for joining an aluminum member and an iron member without plating as a pretreatment.

[0007]

According to the method for joining an aluminum member and an iron member of the present invention, after brazing the joining portion of the iron member, the joining portion and the joining portion of the aluminum member are ultrasonically treated. It is characterized in that it is soldered. In the joining method of the present invention, the brazing can be performed in a reducing atmosphere or using flux. The joining method of the present invention may further include a step of brazing the other joining portion of the iron member and simultaneously joining the other joining portion and the joining portion of the other iron member.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION As the iron member used in the present invention,
Steel, stainless steel, cast iron, etc. can be mentioned, and among them, steel is preferably used in terms of bonding strength. Examples of the aluminum member used in the present invention include a wrought material, a cast material, and a die cast material. Among them, the die cast material is preferably used in terms of cost.

Examples of the brazing material used in the present invention include Cu-based, Ag-based, Ni-based brazing materials which are iron member-based brazing materials, and solder materials for iron members. Above all, Cu
A brazing filler metal is preferably used from the viewpoint of bonding strength.
Further, as the characteristics of the brazing material, those which can be alloyed with the ultrasonic soldering material for aluminum (Al-based solder material) are preferable. Examples of the Cu-based brazing material include JIS BCu-based, BCuZn-based, and BCuP-based materials. Examples of the Ag-based brazing material include JIS BAg-based and BVAg-based materials. As the Ni-based brazing material, for example, JIS BN
i-type can be mentioned. As a solder material for iron members, for example, Sn-Pb-based solder (JIS H60A
Etc.) and Pb-Sn solder (JIS H20A etc.).

Brazing is carried out to remove the oxide film on the surface of the iron member and to protect the surface. As a brazing method, there are a method of brazing in a furnace in a reducing atmosphere or vacuum, and a method of brazing using a flux in the atmosphere. In the case of brazing in a furnace under a reducing atmosphere or in a vacuum, the temperature in the furnace is the melting point of the brazing material (600 to 1).
The temperature is about 100 ° C) plus 10 to 200 ° C.
The heating time is about 10 to 60 minutes. To obtain a reducing atmosphere, for example, carbon monoxide gas, propane-modified gas, butane gas, etc. may be continuously supplied. After brazing in the furnace, it is not necessary to perform post-treatment such as washing with water.

In the case of brazing using a flux in the atmosphere, after the flux and the brazing material are attached to the joint portion of the iron member, 600 to 1 by using a furnace and high frequency induction in the atmosphere.
Heat to about 100 ° C. The heating time is about 5 to 30 minutes. Here, the flux means a substance used for facilitating the wetting of the joint portion by brazing at the time of brazing, and specifically, a substance containing borax, boric acid, hydrochloric acid or the like as a main component is used. After brazing, the residue of the brazed portion is treated before joining with the aluminum member.

The thickness of the film formed by brazing is
The thickness is preferably 1 μm or more in order to prevent oxidation of the iron surface. As the ultrasonic waves used for joining the brazed iron member and the aluminum member with solder, those having a frequency of about 10 to 100 kHz are used. For joining, ultrasonic waves are applied for about 1 to 30 seconds. The heating temperature during ultrasonic bonding is about 380 to 500 ° C.

Examples of the solder used in ultrasonic bonding include Zn-Al type, Zn-Sn type, and Z type.
An n-Cd system etc. can be mentioned. In the present invention,
At the same time as joining the iron members and the aluminum member together, when joining the iron members together, one of the joining portions of the iron member is brazed as a pretreatment for ultrasonic joining with the aluminum member, and the other of the iron members is joined. The joint may be brazed like other iron members.

Next, the production of the composite intake manifold will be described as an example. Figure 1 shows the combined intake
Aluminum flange (die cast product) 1, iron pipe 2, iron surge tank 3 which are the components of the manifold
Indicates. One end of the iron pipe 2 is joined to the aluminum flange 1, and the other end is joined to the iron surge tank 3.

FIG. 2 shows the brazing process with and without the use of flux for brazing. In FIG. 2, a brazing material 4 is applied to each joint of the iron pipe 2 and the iron surge tank 3. When the flux is not used together with the brazing material 4, after heating in the reducing furnace 5 in a reducing atmosphere, the aluminum material and the aluminum flange are joined. When the flux is used together with the brazing material, after heating in the atmospheric furnace 6 open to the atmosphere, the residue is treated,
Join with aluminum flange.

FIG. 3 shows a cross section of the joint between the aluminum flange 1 and the iron pipe 2 when performing ultrasonic joining. In FIG. 3, the iron pipe 2 having the brazing layer 7 is inserted into the joint portion of the aluminum flange 1, and the solder is supplied from the gap between the iron pipe 2 and the heating under heating (about 380 to 500 ° C.). Pressurized (1MP
Ultrasonic waves are applied under the pressure of about a to 10 MPa) to perform the joining.

[0017]

EXAMPLE An example in which the present invention is applied to joining an intake manifold for a four-wheeled vehicle will be described below. 1. Pre-treatment process (brazing) Copper braze (composition: 75% by weight of copper, 25% by weight of binder, melting point: 1083 ° C.) on the joints of both ends of the iron pipe (STKM11A) and the joint of the iron surge tank. Kappa brazing paste M25, manufactured by Shinwa Co., Ltd.) was applied. After coating, this was placed in a reducing furnace that constantly supplies carbon monoxide gas, and held at 1120 ° C. for 60 minutes to perform brazing. As a result, the oxide film on the surface of the joint was removed, and a copper film was formed to a thickness of 10 μm. Simultaneously with the formation of the copper coating, the iron pipe and surge tank were joined.

2. Joining process by ultrasonic soldering The brazed iron pipe is fitted to the aluminum flange (ADC12 die casting material), the molten solder is supplied while heating, and ultrasonic waves (output: 360 W, frequency: 19.6 kHz) are applied. Application was performed for 10 seconds to perform bonding. As a solder, zinc solder for aluminum (Zn
-5% Al, JIS AH-Z95A) was used. As a supply method, a ring-shaped placed solder is installed on the upper end of the joint, and this is heated to 420 ° C. by high frequency induction heating,
It was melted and supplied to the joint.

A pressure leak test and a vibration test of the joined intake manifold were conducted. The pressure leak test was carried out by immersing the work in water and applying a pressure (pressure: 3 kg / cm ² ). As a result, no leakage was found at the joint. For the vibration test, the flange side is fixed and the surge tank side is -3.
It was carried out by applying a tensile / compression load in a load range of 0 to 300 kgf. As a result, the number of repetitions N = 1.8
The iron pipe side broke at 6 × 10 ⁶ . It was found that the joint had fatigue strength higher than that of the iron pipe.

[0020]

According to the present invention, when joining an aluminum member and an iron member, there is no need for masking as in the plating process, and it is sufficient to apply the brazing material only to the joining portion of the iron member. Can be joined to. Further, since the brazing filler metal film is formed only on the joints, the rustproofing treatment on the joints is not affected. Further, the oxide film on the surface of the iron member can be removed by brazing in a reducing atmosphere or by using a flux without performing pickling as in the plating process. Further, since the brazing is performed only on the iron member, there is no possibility that the aluminum member will be melted by the high temperature during brazing.
Furthermore, when the joining of the iron members is also performed at the same time, the pretreatment for ultrasonic joining of the aluminum member and the iron member and the joining of the iron members can be performed in one step of brazing, which is efficient and low. The cost.

[Brief description of drawings]

FIG. 1 is a diagram showing components of an intake manifold.

FIG. 2 is a diagram showing a brazing process of the intake manifold.

FIG. 3 is a view showing a cross section of a joint between an aluminum flange and an iron pipe during ultrasonic joining.

FIG. 4 is a diagram showing a plating process of components of the intake manifold.

[Explanation of symbols]

1 Aluminum flange 2 iron pipe 3 Iron surge tank 4 brazing material 5 Reduction furnace 6 atmospheric reactor 7 Brazing layer 8 plating tank 9 Plating solution 10 Masking

Continuation of front page (51) Int.Cl. ⁷ Identification code FI // B23K 103: 20 B23K 103: 20 (56) References JP-A-52-28445 (JP, A) JP-A-54-85158 (JP, A) JP 62-238066 (JP, A) JP 5-185217 (JP, A) JP 8-290293 (JP, A) JP 10-71465 (JP, A) JP 43 −430 (JP, B1) (58) Fields surveyed (Int.Cl. ⁷ , DB name) B23K 1/06 B23K 1/19-1/20

Claims (3)

(57) [Claims] 1. A method of joining an aluminum member and an iron member, which comprises brazing the joint portion of the iron member and then soldering the joint portion and the joint portion of the aluminum member using ultrasonic waves. . 2. The method for joining an aluminum member and an iron member according to claim 1, wherein the brazing is performed in a reducing atmosphere or using a flux. 3. The aluminum according to claim 1, further comprising the step of brazing the other joint of the iron member and simultaneously joining the other joint and the joint of the other iron member. Method for joining members and iron members.