JPH067995A - Chloride flux buried al brazing filler metal and brazing method using the brazing filler metal - Google Patents

Abstract

PURPOSE:To prevent a color unevenness due to a droop of flux, in the case of variance of flux coating quantity and excessive coating quantity, and a residual flux on brazed surface, concerning the brazing, which uses a chloride flux of Al, Al alloy, etc. CONSTITUTION:The brazing filler metal is composed of the mixture by means of high energy mixing, consisting of the metal powder 2 of Al brazing filler metal and the chloride flux powder 3 with a volume ratio of 99.1:0.1-50:50, in which the flux particle mechanically disperses in the metal powder of brazing filler metal. The brazing filler metal is supplied to joining part of Al or Al alloy to be joined and heated to braze.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the production of aluminum products such as radiators for automobiles, evaporators and condensers for car coolers, other electric machines, heat exchangers for machines, air intake manifolds, or the joining of aluminum and dissimilar metals. The present invention relates to a brazing method of aluminum or its alloy material used in.

[0002]

2. Description of the Related Art Conventionally, when brazing aluminum or its alloy material or brazing aluminum with a dissimilar metal is carried out by chloride flux brazing, the brazing material is supplied to the joint and the flux is suspended. It was carried out by applying a turbid solution to the solution and heating it in this state.

However, in such a conventional chloride flux brazing, the brazing filler metal and the chloride flux must be separately supplied to the joint, so that the work is troublesome. Moreover, the amount of applied flux varies, and when the amount of applied flux is large, it causes dripping of flux during brazing to contaminate the brazing furnace. There were problems such as unevenness.

On the other hand, in order to eliminate the separate supply of the chloride flux and the brazing filler metal to the joint, Al which constitutes the brazing filler metal is used.
-Si powder and flux powder are mixed with a binder such as acrylic to make a liquid, and this is applied to a joining member to simplify the work.

However, in this case, it is difficult to mix the brazing filler metal powder and the flux uniformly, so that the amount of flux adhered varies, resulting in defective brazing due to insufficient flux and flux residue on the surface of the brazed product due to excessive flux. there were.

The present invention has been made in view of the above technical background, and in flux brazing using a chloride flux of aluminum or its alloy material, when there are variations in the amount of flux applied and a large amount of flux applied. The purpose is to prevent flux dripping, color unevenness due to residual flux on the surface of the brazed product, and to prevent brazing failure when a binder is used. The present invention provides a method and a brazing method using the brazing material.

[0007]

In order to achieve the above object, one of the present inventions is a volume ratio of 99.9: 0.1-5.
It is composed of a mixture of 0:50 Al brazing metal powder and chloride-based Fuchs powder by a high energy mixing method, and flux particles are mechanically dispersed in the brazing metal particles. The subject matter is a chloride-based flux-embedded Al brazing material.

The other one relates to the above method for producing a brazing filler metal, in which a metal powder for an Al brazing filler metal having a volume ratio of 99.9: 0.1 to 50:50 and a chloride-based Fuchs powder are used. The gist of the present invention is to provide a method for producing a chloride-based flux-embedded Al brazing material, which is characterized by mixing by an energy mixing method and mechanically dispersing chloride-based flux particles in the brazing material metal particles.

Still another one relates to a brazing method using the above brazing material, in which a brazing material in which chloride flux particles are embedded in a metal powder for Al brazing material is dispersed, and the brazing material is joined. It is a gist of a brazing method of aluminum or its alloy material, which comprises supplying the aluminum or its alloy material to be joined to a portion to be joined and heating it for brazing.

In the above, as the metal powder for the Al brazing material, an Al--Si alloy powder containing Si: about 3 to 15 wt% which has been conventionally used, or for the purpose of further improving the strength as required. For Mg: 0.1
Al-containing about 5.0 wt%, Zn: about 0.1 to 3.0 wt%, or one or more Cu.
Si-Mg system, Al-Si-Zn system, Al-Si-Mg
-Zn-based alloy powders may be used. Further, it is not always necessary to use it in the form of alloy powder at the stage of the starting material for manufacturing the brazing material, but Al, Si,
Powder of a simple metal such as Mg or Zn may be used.

The type of the chloride-based flux is not particularly limited, but in order to exert an effective flux action, a chloride-based mixture or a simple substance flux that melts at about 595 ° C. or lower may be used. For example, KC
Examples of the main component include l, NaCl, BaCl ₂ , ZnCl _{2 and the} like. In addition to the above main components, a fluoride-based flux such as KAlF ₄ , KF + AlF ₃ ,
CsαAlFα + 3, KSnF ₃ , KZnF ₃ , CsF,
It is also recommended to add about 1 to 5 wt% of one or _two of SnF ₂ and ZnF ₂ . The reason for this is that the chloride-based flux alone has a too low melting point. Therefore, the inclusion of a fluoride increases the melting point and improves brazing properties. However, if the fluoride content exceeds 5 wt%, the flux residue will increase. And the residue may be difficult to remove by washing with water or hot water.

Next, a preferred method for manufacturing the brazing filler metal according to the present invention is as follows. That is, first, the metal powder for Al brazing material and the flux powder are mixed by a high energy mixing method. The mixing ratio in terms of volume ratio is brazing filler metal powder: chloride flux powder = 99.9: 0.1.
It is preferable to set the ratio to 50:50. When the amount of flux is less than 99.9: 0.1 by volume ratio, that is, 0.
This is because if it is less than 1%, a sufficient flux action cannot be exhibited in the subsequent brazing, and brazing may be difficult. On the other hand, if the amount of flux is more than 50:50, that is, if the amount of flux exceeds 50%, the amount of the flux is too large, causing dripping of the flux and contaminating the brazing furnace, or a large amount on the surface of the brazed product. There is a risk of inconvenience such as residual flux being generated and uneven color tone being exhibited. A particularly preferable mixing ratio of the Al brazing metal powder and the chloride flux powder is 99.5: 0.
It is 5 to 70:30. In order to uniformly embed the flux in the brazing powder, the brazing powder has a particle size of 20 to 1000 μm, preferably 100 to 1000 μm.
It is better to set the particle size of the flux powder to 20
˜200 μm, preferably 20 to 100 μm.

The high-energy mixing method for mixing the brazing filler metal powder and the chloride-based flux powder is carried out by mixing both powders while applying a strong compressive force or impact force to the brazing filler metal particles. This is a mixing method in which flux particles are mechanically dispersed. Specifically, for example, a method using a high energy ball mill or an attritor can be mentioned.
In the high-energy ball mill treatment, as shown in FIG. 1 (a), a metal powder (2) for Al brazing material and a flux powder (3) are charged into a container (1), and Al ₂ O 3 balls or steel balls ( 4) is put, and in this state, the mill is rotated as shown in FIG. 2B so that the powder is mixed with the falling impact force of the balls or steel balls (4) acting on the powder. The method using an attritor is shown in FIG.
(A) As shown in (b), a stirring arm is placed in a container (1) containing a metal powder (2) for Al brazing material, a flux powder (3) and an Al ₂ O ₃ ball or a steel ball (4). The stirring bar (5) having a large number of protrusions (5a) is rotated to mix while applying a compressive force. By mixing using such a high-energy ball mill or attritor, a part of the powder becomes a composite powder, and the flux powder is further composited. As shown in FIG. 3, the brazing filler metal particles (6) are mixed with a chloride-based flux. A brazing filler metal powder is produced in which the particles (7) are mechanically uniformly dispersed in the embedded state.

Brazing is performed using the brazing filler metal containing chloride flux embedded as described above. The brazing powder is suspended in an alcohol solvent, water, etc., and then the suspension is joined. To be welded to the aluminum or its alloy material to be bonded. Since the amount of the mixed flux is regulated within a certain range, the flux can be applied uniformly without excess or deficiency in the amount of adhered flux.

After that, the joining member is heated to perform brazing. The surface oxide film on the joint is removed by the action of the chloride flux embedded in the brazing material powder, the brazing material spreads wet, and good and strong brazing joining is achieved as if flux was applied separately. To be done. Therefore, it is no longer necessary to separately apply the flux. After brazing, wash with hot water or water if necessary.

[0016]

Embodiments of the present invention will be described below.

Example 1 As a metal powder for brazing material, A
1-10 wt% Si alloy powder (average particle size 140 μm) was prepared. In addition, as a chloride-based flux powder, ZnC
the l ₂ as a main component was prepared this that the KAlF ₄ was allowed containing 2 wt% (average particle size 74 .mu.m).

Next, the brazing metal powder and the flux powder were mixed in an attritor at a volume ratio of 95: 5 to produce a flux-embedded brazing filler metal powder.

On the other hand, an extruded tube made of A1100Al alloy having a thickness of 0.8 mm and a fin material made of A3003Al alloy were assembled into a corrugated heat exchanger. Then, the flux-embedding brazing filler metal powder is suspended in water, the suspension is uniformly applied to the heat exchanger assembly, and then the brazing is performed by heating at 600 ° C. for 5 minutes in an N ₂ atmosphere. It was

Example 2 Brazing was performed under the same conditions as in Example 1 except that the volume ratio of the brazing filler metal powder to the chloride flux powder was set to 99.9: 0.1.

Example 3 Brazing was performed under the same conditions as in Example 1 except that the volume ratio of the brazing filler metal powder to the chloride flux powder was set to 50:50.

(Example 4) The metal powder for brazing filler metal of Example 1 and the chloride type flux powder were set to a volume ratio of 95: 5 and mixed by a high energy ball mill to produce a brazing filler metal powder for flux embedding. .

On the other hand, the A6063 union material was assembled into an extruded tube made of A1100Al alloy having a wall thickness of 0.8 mm, and the joint portion thereof was coated with a suspension of the above-mentioned flux embedding brazing material powder in water. _A brazed product was obtained by heating at 605 ° C. for 5 minutes in ₂ atmospheres.

Example 5 Brazing was performed under the same conditions as in Example 5 except that the volume ratio of the brazing filler metal powder to the chloride flux powder was set to 99: 1.

Example 6 Brazing was performed under the same conditions as in Example 5 except that the volume ratio of the brazing filler metal powder to the chloride flux powder was set to 60:40.

(Comparative Example 1) A1100 extruded tube,
A brazing sheet fin material having A3003 material as a core material and A4343 material as a liner material was assembled into a heat exchanger. Then, this heat exchanger assembly was dipped in a 10 wt% flux suspension using the same flux as in Example 1, dried and then heated in an N ₂ atmosphere at 600 ° C. for 5 minutes for brazing.

(Comparative Example 2) A6063 union material was assembled into an extruded tube made of A1100Al alloy, and
An A4045Al brazing material plate was inserted into the joint portion, a 20 wt% flux suspension containing the same chloride flux as in Example 1 was applied, and after drying, 600 ° C. in an N ₂ atmosphere.
X Brazing was performed by heating for 3 minutes.

With respect to the eight kinds of brazed products obtained above,
The following inspection was performed.

Inspection of brazing property The fin joining rate or the brazing filling rate is investigated, and the fin joining rate of 100% or the brazing filling rate of 100% is ◯, the fin joining rate is 90% or more and less than 100%, or the brazing rate is 90%. More than less than 100% is △, fin bonding rate is 90
% Or a wax filling rate of less than 90% was shown as x.

Inspection of appearance state after brazing Visually observing the surface of the brazed product, it is possible to visually confirm the residue of flux, and the appearance is extremely clean. did.

Inspection of Surface Treatability After brazing, each brazed product is washed with hot water and then with water,
The surface of the brazed product is spray-painted, and 100 squares are marked on the surface to carry out a tape peeling test.
A so-called cross-cut test was performed in which the number of squares remaining in the coating film was counted with respect to the total number of squares.

Table 1 shows the above inspection results.

[0033]

[Table 1] From the results shown in Table 1, according to the chloride-flux-embedded Al brazing filler metal powder produced according to the present invention, excellent brazing properties can be exhibited without applying a chloride-based flux separately, and the chloride-based flux remains. However, it was confirmed that the external appearance was excellent and the surface treatment property was also excellent.

[0034]

[Function] During brazing, the surface oxide film on the joint is removed by the chloride flux embedded in the brazing powder, the brazing material spreads wet, and is as good as when chloride flux is separately applied. And a strong brazing joint is achieved. Therefore, it is no longer necessary to separately apply the chloride flux.

[0035]

The chloride flux-embedded Al brazing material according to the present invention has a volume ratio of 99.9: 0.
1-50: 50 Al brazing filler metal powder and chloride-based Fuchs powder mixed by a high energy mixing method, wherein the flux particles are mechanically dispersed in the brazing filler metal particles. Because it is characterized by
Good brazing can be performed only by supplying this brazing material to the part to be joined of aluminum or its alloy material to be joined and heating it, and it is not necessary to separately supply a chloride flux. For this reason, the process of applying the chloride-based flux can be eliminated, the joining work efficiency can be improved, and the productivity of the aluminum brazed product can be improved.

Moreover, since the amount of the chloride-based flux mixed with the brazing filler metal powder is regulated within a certain range, the amount of the chloride-based flux applied varies as in the case of applying the flux suspension. There is no risk of causing flux, and even if a small amount of coating is applied, the flux function can be reliably exhibited, and the brazing furnace is contaminated due to too much flux coating, or the surface of the brazed product due to residual flux. Inconvenience such as occurrence of color unevenness can be eliminated.

[Brief description of drawings]

FIG. 1 is a schematic diagram for explaining a mixing method using a high energy ball mill.

FIG. 2 is a schematic diagram for explaining a mixing method using an attritor.

FIG. 3 is a schematic enlarged view of a manufactured chloride-based flux-embedded brazing filler metal powder.

[Explanation of symbols]

 2 ... braze metal powder 3 ... chloride flux powder 6 ... braze metal particles 7 ... chloride flux particles

Claims (3)

[Claims] 1. A brazing filler metal particle comprising a mixture of an Al brazing filler metal powder having a volume ratio of 99.9: 0.1 to 50:50 and a chloride-based Fuchs powder by a high energy mixing method. A chloride-based flux-embedded Al brazing material, in which flux particles are mechanically dispersed. 2. A brazing filler metal powder having a volume ratio of 99.9: 0.1 to 50:50 and a chloride-based Fuchs powder are mixed by a high energy mixing method to form chloride in the brazing filler metal particles. A method for producing a chloride-based flux-embedded Al brazing material, which comprises mechanically dispersing material-based flux particles. 3. A brazing material in which chloride-based flux particles are dispersed in a metal powder for Al brazing material is used, and the brazing material is supplied to a portion to be joined of aluminum or its alloy material to be joined and heated. A brazing method of aluminum or its alloy material, which comprises brazing.