JPH09225631A - Joining - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method capable of joining an aluminum or aluminum alloy with the aluminum, or with the aluminum alloy or a steel without necessitating any particular material or special process. SOLUTION: After a coating layer 3 of potassium silicofluoride is formed on a surface 1a to be joined of at least one of a members 1 and 2 composing of stock made of the aluminum or aluminum alloy or steel, surfaces 1a and 2a to be joined of members 1 and 2 are butted via the coating layer 3 and heated to generate an eutectic reaction between the silicon of coating layer 3 and the aluminum, thereby connecting members 1 and 2 together. By this way, as soon as a diffusion joining reaction of silicon is generated, a reaction material breaking an oxide film of aluminum and aluminum alloy is allowed to produce, whereby a brazed product having low producing cost and high joining strength is obtained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a joining method, and more particularly to a joining method in which potassium silicofluoride is used for joining aluminum or an aluminum alloy and aluminum, an aluminum alloy or steel.

[0002]

2. Description of the Related Art Generally, a welding method is used as a lightweight and corrosion-resistant joining method. This welding method has an advantage that strong joining is possible because metal fusion is used. However, since fusion is performed by applying large heating only to the joined parts, there is a problem that if the heat capacity of the joined materials is small, melting of the base material itself easily occurs, and joining of minute members becomes difficult. ing. Further, there is a problem that surface bonding is generally difficult because it is difficult to apply large heating.

[0003]

Therefore, when joining fine members by the welding method, the welded portion is sufficiently melted,
And it is necessary to form a situation in which the base material is not melted. However, this requires a high degree of condition management, and thus requires high skill for the worker, and it takes many years to acquire the skill. In addition, the required equipment will be expensive and require sufficient functions to realize advanced condition management.
Moreover, even with a skilled technician and expensive equipment, a sound joint cannot always be obtained, and a soundness inspection after joining is often required. Therefore, the production cost is significantly increased, and the product cost is soaring.

The object of the present invention is made in view of the above circumstances, and an object thereof is to enable joining of aluminum or aluminum alloy and aluminum, aluminum alloy or steel without using special skill and equipment. It is to provide the joining method.

[0005]

According to the first aspect of the present invention,
In a method of joining aluminum or an aluminum alloy and aluminum, an aluminum alloy or steel, at least one of the surfaces to be joined is made of potassium silicofluoride (K2Si).
F6) the first step of forming a coating layer, and the joining surface of the member is butted against the coating layer through the coating layer and heated to cause a eutectic reaction of silicon and aluminum in the coating layer. And a second step of connecting them to each other.

The invention according to claim 2 is characterized in that, in the invention according to claim 1, the second step is performed in an inert gas atmosphere.

According to a third aspect of the present invention, in the invention according to the first or second aspect, the coating layer is formed by applying or spraying a slurry solution of potassium silicofluoride powder on the surfaces to be joined and then drying the slurry solution. It is characterized by that.

According to the first aspect of the present invention, the surfaces to be joined of the members of aluminum or aluminum alloy and aluminum, aluminum alloy or steel are metallically joined to each other by the eutectic reaction of silicon and aluminum. The reaction product (KAlF ₄ + K ₂ AlF ₅ ) destroys the oxide film of aluminum and aluminum alloy. For this reason, it becomes possible to join aluminum or aluminum alloy and aluminum, aluminum alloy or steel without requiring expensive machines such as a welding machine and high skill, thus significantly reducing the total production cost. Can be lowered.

According to the second aspect of the present invention, the formation of the oxide film is suppressed by the atmosphere of the inert gas such as nitrogen gas. Therefore, a high quality bonding layer is formed,
The reliability of joining is increased as much as possible.

According to the third aspect of the invention, the coating layer can be uniformly and easily formed on the surfaces to be joined.
It is possible to improve transportability and storability as well as cost reduction.

[0011]

Embodiments of the present invention will be described below in detail with reference to the accompanying drawings.

The method of joining aluminum or aluminum alloy and aluminum, aluminum alloy or steel according to the present invention is, for example, as shown in FIG. 1, at least one of members 1 and 2 made of aluminum and aluminum alloy as raw materials. The coating layer 3 for joining is formed on the joined surface 1a of the member 1.

The materials of the members 1 and 2 to be joined are
For example, JIS A3003, JIS A1050 or the like is used, and as a material for forming the coating layer 3, for example, a slurry solution obtained by adding powder of potassium silicofluoride (K ₂ SiF ₆ ) to water is used.

The coating or spraying of the slurry solution as the coating layer forming material is even and uniform with respect to the surface 1a to be joined of the member 1, and the weight per unit area of potassium silicofluoride is, for example, 4 g / m ^{2 to} 40 g. performed such that / m ^2.

After the application or spraying of the slurry solution is completed, it is then dried naturally or artificially. After this drying, the members 1 and 2 to be joined are joined.

In the joining, the surface to be joined 2a of the other member 2 is overlapped and abutted against the coating layer 1a of the member 1 to be connected, and the abutted state is maintained to make the whole inert gas such as nitrogen gas. It is carried out by placing in an atmosphere and then heating the entire inert gas to a high temperature. Of course, in an inert gas atmosphere, the members 1 to be joined including the coating layer 1
It is also possible to partially heat the periphery of 2 in an inert gas atmosphere.

The heating is adjusted so that the following reaction occurs while the temperatures of the surfaces 1a, 2a to be joined and the coating layer 3 reach approximately 600 ° C.

3K ₂ SiF ₆ + 4Al → 3Si + 2KAlF
₄ + 2K ₂ AlF ₅ i.e., the bonding method according to the present invention, as the reaction formula, the KAlF ₄ + K ₂ AlF ₅ that exerts the same effect as the corrosive flux by heating to decompose extracted this KAlF ₄ + K the ₂ AlF _5, with destroying remove the aluminum or oxide coatings on aluminum alloy material,
At the same time, Si is decomposed and extracted, and the bonded surfaces 1a, 2a
The eutectic reaction with the aluminum or aluminum alloy material mentioned above causes the surface layer of the joint surface to be an Al-Si alloy. Therefore, according to this method, the joining state becomes a good state with high joining strength, and the production cost can be significantly reduced.

[0019]

EXAMPLES Next, examples of the present invention will be described. ◎ Example 1 First, powder of potassium silicofluoride (K ₂ SiF ₆ ) was added to tap water to prepare a slurry solution as a coating layer forming material,
This slurry solution was applied to one joint surface 4a of the member 4 to be connected by brush coating and dried as shown in FIG.

After drying, the surface 5b to be joined of the other member 5 to be connected to the coating layer 3a is overlaid on the T-shape and abutted, and this is heated and joined under the following conditions. evaluated.

In the first embodiment, the members 4 and 5 to be joined to each other are plate materials made of JIS A1050 alloy.

(1) Slurry concentration: 15% {potassium silicofluoride (K ₂ SiF ₆ ) powder} (2) Coating amount: 20 g / m ² (3) Heating atmosphere; Nitrogen gas atmosphere (dew point -40 ° C) ( 4) Heating temperature: 600 ° C. According to this example, a fillet was also formed at the joint, and the brazing condition was 100% good.

Example 2 A powder solution of potassium silicofluoride (K ₂ SiF ₆ ) was added to tap water to prepare a slurry solution as a coating layer forming material, and the slurry solution was sprayed to the members to be connected as shown in FIG. 6 is sprayed on one joint surface 6a, then dried, and after drying, the joint surface 7b of the other member 7 to be connected is superposed on the coating layer 3b of one member 6 to be connected, and this superposition is performed. In the combined state, heat the whole under the following heating conditions,
The joined state and appearance of the connected members 6 and 7 were evaluated.

In the second embodiment, the members 6 and 7 to be joined to each other are plate materials made of JIS A3003 alloy.

(1) Slurry concentration: 15% {potassium silicofluoride (K ₂ SiF ₆ ) powder} (2) Coating amount: 20 g / m ² (3) Heating atmosphere; Nitrogen gas atmosphere (dew point -40 ° C) ( 4) Heating temperature: 600 ° C. According to this example, the brazing state was good even in the joining of the surfaces, and the joining rate was 95% or more.

Example 3 First, potassium silicofluoride (K ₂ SiF ₆ ) powder was added to tap water to prepare a slurry solution as a coating layer forming material, and this slurry solution was applied by brushing as shown in FIG. It is applied to one joint surface 8a of the member 8 to be connected to and dried.

After drying, the joint surface 9b of the other member 9 to be connected to the coating layer 3c was placed in a T-shape and abutted against each other, and this was heated and joined under the following conditions, and then the joint state and appearance were evaluated. .

In the third embodiment, the member 8 is JIS
A plate made of A3003 alloy is used, and the member 9 is SUS3.
04 plate material was used.

(1) Slurry concentration; 15% {potassium silicofluoride (K ₂ SiF ₆ ) powder} (2) coating amount; 30 g / m ² (3) heating atmosphere; nitrogen gas atmosphere (dew point -40 ° C) ( 4) Heating temperature: 600 ° C. According to this example, a fillet was also formed at the joint, and the brazing condition was 100% good.

[0030]

【The invention's effect】

1) According to the invention of claim 1, a eutectic reaction of silicon and aluminum and a reaction of forming a reactant that destroys an oxide film of aluminum and an aluminum alloy can be simultaneously generated, which is simple and low. The members can be joined together at a cost.

2) According to the invention described in claim 2, the formation of an oxide film can be suppressed by an inert gas atmosphere, and a bonding layer of higher quality than that of the invention described in claim 1 is formed. The reliability can be improved as much as possible.

3) According to the invention described in claim 3, the coating layer can be uniformly and easily formed on the surfaces to be joined. Therefore, it is possible to reduce the cost and improve the transportability and the storability.

[Brief description of drawings]

FIG. 1 is a process drawing showing a joining method according to the present invention.

FIG. 2 is a perspective view showing a first embodiment of a joining method according to the present invention.

FIG. 3 is a perspective view showing a second embodiment of the joining method according to the present invention.

FIG. 4 is a perspective view showing a third embodiment of the joining method according to the present invention.

[Explanation of symbols]

1, 4, 6, 8 One member to be connected 2, 5, 7, 9 Other member to be connected 1a, 4a, 6a, 8a Joined surface 2b, 5b, 7b, 9b of one member to be connected Joined surface of the other member to be connected 3,3a, 3b, 3c Coating layer

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification number Office reference number FI technical display location B23K 35/363 B23K 35/363 G // B23K 103: 10 103: 20 (72) Inventor Akinori Ogasawara 2-20 Higashi-Shinagawa, Shinagawa-ku, Tokyo Tennozu Yusen Building Nippon Light Metal Co., Ltd.

Claims (3)

[Claims] 1. A method of joining aluminum or an aluminum alloy and aluminum, an aluminum alloy or steel, wherein a first step of forming a coating layer of potassium silicofluoride on a surface to be joined of at least one member, and the step of interposing the coating layer therebetween. A second step of connecting the members to each other by abutting the surfaces to be joined of the members with each other and heating to cause a eutectic reaction of silicon and aluminum in the coating layer. . 2. The joining method according to claim 1, wherein the second step is performed in an inert gas atmosphere. 3. The bonding according to claim 1, wherein the coating layer is formed by applying or spraying a slurry solution of potassium silicofluoride powder on the surfaces to be bonded and then drying. Method.