JPH09300095A - Aluminum brazing material - Google Patents

Abstract

(57) Abstract: A Si layer for forming a molten braze is uniformly formed on a brazing joint surface of an aluminum member, and a uniform and stable brazing joint is possible without using a brazing sheet. An aluminum brazing member is provided. An aluminum brazing member for forming a molten braze on a joint surface and brazing and joining another aluminum member, the Si layer having an average thickness of 0.5 to 100 μm on the joint surface with the other aluminum member. To provide. The Si layer is preferably formed by vapor deposition, sputtering or ion plating. A metal layer such as a Zn layer for forming a sacrificial anode layer can be provided below the Si layer.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an aluminum (including an aluminum alloy, the same applies hereinafter) brazing member, and more particularly to an aluminum brazing member that is brazed to another aluminum member in an aluminum heat exchanger. .

[0002]

2. Description of the Related Art Aluminum heat exchangers are conventionally known as shown in FIG.
As shown in (1), an aluminum fin material 2 made of a brazing sheet clad with an Al-Si alloy brazing (for example, a cladding rate of 10%) is assembled with a tube material 1 made of a flat multi-hole aluminum tube, and flux brazing is performed. Alternatively, it is assembled by performing fluxless brazing such as vacuum brazing or atmosphere brazing.

In recent years, from the viewpoint of reducing the weight of an aluminum heat exchanger, it has been required to reduce the thickness of an aluminum fin material. In this case, the fin material is changed from a brazing sheet to a bare material, and If the brazing material can be clad with the material, further thinning of the fin material can be expected. However, at present, no method has been established for coating an aluminum-tube material with an Al-Si brazing material stably and inexpensively on an industrial scale.

As a method applicable to coating a brazing material on a tube material, an aluminum material is dipped in a slurry of a mixture of flux and silicon metal powder, heated and dried to apply the mixture to the surface of the aluminum material. A method has been proposed in which the materials are combined and heated in a brazing furnace to form an Al—Si-based molten braze on the joint surface to perform brazing (Japanese Patent Publication No. 6-504485, Japanese Patent Publication No. (Kaihei 7-308795 gazette), a method of depositing a Zn-Si alloy on the surface of an aluminum porous flat extruded tube material by thermal spraying, combining fin materials, heating, and brazing is also proposed,
These methods have a drawback in that the coating or coating operation is troublesome and the cost is high, and uniform coating is difficult, and the adhesion of the Si powder tends to be insufficient, so that uniform and stable brazing and joining are difficult to perform.

[0005]

SUMMARY OF THE INVENTION The present invention is an improvement for providing a coating layer for forming an Al--Si type molten braze on a surface of an aluminum member, particularly an aluminum tube member, which is to be joined with another aluminum member. The purpose of the present invention is to provide a uniform and stable coating layer, in which a uniform and thin coating layer is formed and the dimensional change of the assembly is not caused by the outflow of the molten solder. It is an object of the present invention to provide an aluminum brazing member that enables brazing and bonding, and can easily and inexpensively form a coating layer.

[0006]

The aluminum brazing member according to the present invention for achieving the above-mentioned object is an aluminum brazing member for forming a molten braze on a joining surface and brazing and joining another aluminum member. The average thickness of the joint surface with other aluminum members is 0.5
The first structural feature is the provision of a Si layer of -100 μm.

The Si layer is made of Si, Ag, Cu, G
a, Ge, Li, Mg, Re, Sn, Zn, In, P
d, Se, Au, Be, Ca, Ce, Dy, La, N
A second feature is that the metal is composed of one or more elements of d, Ni, Sm, Tb, and Y, and a metal composed of one or more of the above elements is provided above or below the Si layer. A third feature is that the layers are provided in a stacked manner.

Further, under the Si layer, Zn, In, S
The fourth characteristic is to provide a metal layer made of at least one of n and Ga, and the metal layer has an average thickness of 0.1 to 5 μm.
Zn layer or a metal layer having an average thickness of 0.1 to 5 μm and made of at least one of Zn and In, Sn, Ga, or Z
A fifth feature is that the metal layer is made of one or more of n, In, Sn, and Ga and has an average thickness of 0.01 to 0.5 μm.

The sixth, seventh and eighth characteristics of the aluminum brazing member according to the present invention are that a pure aluminum layer is interposed between the aluminum brazing member and the Zn layer or the metal layer, and the aluminum brazing member has a multi-hole flat surface. Being a tube, and S
The i layer, the Zn layer, and the metal layer are formed by vapor deposition, sputtering, or ion plating.

In the present invention, the Si layer formed on the joining surface of the aluminum member is diffused into the aluminum member and other aluminum members to be joined during brazing and heating to form an Al--Si alloy layer. Then, the solder becomes molten and brazing is performed. The thickness of the Si layer is preferably in the range of 0.5 to 100 μm in average thickness.
If the thickness exceeds μm, excessive brazing filler metal will be supplied to the fillet during brazing, resulting in problems such as buckling due to holes in the material, especially when other aluminum members to be joined are thin, such as fin material. Is likely to occur. The more preferable thickness of the Si layer is in the range of 1 to 20 μm.

The Si layer is composed of Si, Ag, Cu, Ga, G
e, Li, Mg, Re, Sn, Zn, In, Pd, S
e, Au, Be, Ca, Ce, Dy, La, Nd, N
i, Sm, Tb, Y having an average thickness of 0.5 to 100 μm consisting of one or more elements, or above or below the Si layer, having an average thickness of one or more of the above elements 0 .
By laminating and providing a metal layer of 01 to 0.5 μm, these elements form a eutectic with the Al-Si alloy, so that the melting temperature of the Al-Si brazing filler metal formed is lowered, for example, at 580 ° C. Brazing can be performed at the following low temperatures.

Particularly, under the Si layer, Zn, In, S
By providing a metal layer made of at least one of n and Ga, Zn, In, Sn, and Ga diffuse into the aluminum member during brazing and heating, resulting in Al-Zn alloy and Al-In.
Alloy, Al-Sn alloy, Al-Ga alloy layer is formed,
These layers give the aluminum member a sacrificial anode effect,
Improves corrosion resistance.

In a first mode of this case, a Zn layer or a metal layer composed of Zn and one or more of In, Sn and Ga is formed as the metal layer. Average layer thickness is 0.1
A range of ˜5 μm is preferable, and if it is less than 0.1 μm, it is difficult to obtain the sacrificial anode effect. In a second mode, the metal layer is made of In, S
forming a metal layer made of one or more of n and Ga,
The average layer thickness is preferably 0.01-0.5 μm, 0.01 μm
If it is less than m, the sacrificial anode effect is small, and if it exceeds 0.5 μm, the self-corrosion in the diffusion part becomes large and the corrosion of the brazing part is promoted.

A pure aluminum layer may be provided between the Si layer and the Zn layer or the metal layer. In this case also, Si is diffused into the pure aluminum layer during heating by brazing and Al-
A Si alloy is formed and becomes a molten braze, and brazing and bonding are performed, and Zn, In, Sn, and Ga diffuse into the pure aluminum layer to form a sacrificial anode layer and improve the corrosion resistance of the aluminum member.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION In the present invention, as the aluminum brazing member, in addition to a plate material, a bar material, a pipe material, a wire material,
A member having a complicated shape can also be applied. If necessary, after processing these materials, apply S, by vapor deposition, sputtering, or ion plating to the bonding surface with other aluminum members.
An i layer, a Zn layer, and a metal layer are formed. By these means, thin and uniform layers can be obtained.

In particular, as shown in FIG. 2, by providing the coating layer 5 made of Si layer on the flat surfaces 3 and 4 of the aluminum multi-hole flat tube 1 which becomes the working fluid passage in the aluminum heat exchanger, The fin material 2 to be assembled on the flat surface can be brazed by using a bare aluminum material instead of a brazing sheet, and thus the fin material can be further thinned.

According to the present invention, a normal aluminum alloy material can be used in place of the brazing sheet as the plate material constituting the member of the aluminum heat exchanger, and the plate material having the coating layer such as the Si layer is the brazing sheet. Since it has better moldability, there are few restrictions in press working, and it is possible to form the coating layer after working even in pressed ones and those having a complicated shape by forging or cutting.

Among the heat exchangers made of aluminum, a heat exchanger composed of a tube material such as a multi-hole flat tube, a fin material and a header tube, such as a parallel flow condenser, has a structure as shown in FIG. , Both end portions of the tube material 1 to be inserted into the header pipe 6 require more brazing than the central portion where the tube material 1 contacts the fin material 2, but according to the present invention, first, the flat surface of the tube material 1 is After forming the coating layer 5 on the entire surface, portions of the tube material 1 to be inserted into the header pipe 6 other than the both end portions are masked, and a coating layer is further provided on the first formed coating layer 5 at both end portions. A thick coating layer 7 can be used.

[0019]

EXAMPLES Hereinafter, examples will be described in comparison with comparative examples. Example 1 JIS 1100 alloy was extruded by port hole extrusion into a flat porous tube (8 holes) having a cross section as shown in FIG. ^Apply 1 × 10 ^-6 To on the upper and lower flat surfaces of the obtained tube material.
An Si layer having an average thickness of 5 μm was formed by vapor deposition in a vacuum of rr. As shown in FIG. 1, the obtained Si layer-covered tube material was treated with an aluminum fin material (Al-1.2 wt% Mn-
It was combined with 1.5 wt% Zn (JIS 3003 + 1.5 wt% Zn)), heated to a temperature of 600 ° C. for 3 minutes, and brazed. After brazing, a sound fillet was formed between the tube material and the fin material, and no buckling was observed.

Example 2 On the upper and lower flat surfaces of the tube material obtained in Example 1, 1 ×
Zn with an average thickness of 1 μm was formed by vapor deposition in a vacuum of 10 ^-6 Torr.
After forming the layer, a Si layer having an average thickness of 5 μm was also deposited on the Zn layer by vapor deposition. As shown in FIG. 1, the obtained metal layer-covered tube material was combined with the same aluminum fin material as in Example 1 and brazed under the same conditions as in Example 1. After brazing, a sound fillet was formed between the tube material and the fin material, and buckling was not observed. The heat exchanger element thus obtained was subjected to a CASS test for 2 weeks, but no through hole was observed in the tube material.

Example 3 On the upper and lower flat surfaces of the tube material obtained in Example 1, 1 ×
The average thickness is 0 by sputtering in a vacuum of 10 ^-6 Torr.
After forming an In layer of 02 μm, a Si layer having an average thickness of 4 μm was deposited on the In layer by the same sputtering. The obtained metal-coated tube material was combined with the same aluminum fin material as in Example 1 as shown in FIG.
Brazing and joining were performed under the same conditions as in Example 1. After brazing, a sound fillet was formed between the tube material and the fin material, and buckling was not observed. The obtained heat exchanger element was subjected to a CASS test for 2 weeks, but no through hole was formed in the tube material.

Example 4 On the upper and lower flat surfaces of the tube material obtained in Example 1, 1 ×
After a Sn layer having an average thickness of 0.02 μm was formed by ion plating in a vacuum of 10 ⁻⁶ Torr, a Si layer having an average thickness of 10 μm was deposited on the Sn layer by vapor deposition. The metal layer-coated tube material thus obtained was used in Example 1 as shown in FIG.
The same aluminum fin material was used and brazed under the same conditions as in Example 1. After brazing, a sound fillet was formed between the tube material and the fin material, and buckling was not observed. When the obtained heat exchanger element was subjected to a CASS test for 2 weeks, no through hole was formed in the tube material.

Example 5 On the upper and lower flat surfaces of the tube material obtained in Example 1, 1 ×
In vacuum of 10 ^-6 Torr, the average thickness of 0.1 μm G
After forming the a layer, a Si layer having an average thickness of 3 μm was deposited on the Ga layer by vapor deposition. As shown in FIG. 1, the obtained metal layer-covered tube material was combined with the same aluminum fin material as in Example 1 and brazed under the same conditions as in Example 1. After brazing, a sound fillet was formed between the tube material and the fin material, and buckling was not observed. The obtained heat exchanger element was subjected to a CASS test for 2 weeks, but no through hole was formed in the tube material.

Example 6 On the upper and lower flat surfaces of the tube material obtained in Example 1, 1 ×
In vacuum of 10 ^-6 Torr, S with an average thickness of 0.1 μm was deposited.
After forming the n, Zn mixed layer, a Si layer having an average thickness of 5 μm was deposited on the mixed layer by vapor deposition. As shown in FIG. 1, the obtained metal layer-covered tube material was combined with the same aluminum fin material as in Example 1 and brazed under the same conditions as in Example 1. After brazing, a sound fillet was formed between the tube material and the fin material, and buckling was not observed. The obtained heat exchanger element was subjected to a CASS test for 2 weeks, but no through hole was formed in the tube material.

Example 7 On the upper and lower flat surfaces of the tube material obtained in Example 1, 1 ×
Of 10 ^-6 Torr in vacuum, the average thickness of the deposition 18μm and
A 40 μm Si layer was formed. As shown in FIG. 1, the obtained Si layer-covered tube material was combined with the same aluminum fin material as in Example 1 and brazed under the same conditions as in Example 1. In the case where the 18 μm Si layer was formed, a sound fillet was formed between the tube material and the fin material after brazing. On the other hand, in the case where the Si layer having a thickness of 40 μm was formed, the formed fillet had no problem in practical use, but since the braze was supplied in a slightly excessive amount, some erosion due to the molten braze was observed in the fin material.

Example 8 1 × was formed on the upper and lower flat surfaces of the tube material obtained in Example 1.
Si in an average thickness of 5 μm by vapor deposition in a vacuum of 10 ^-6 Torr
A layer was formed, and a Cu layer having an average thickness of 0.2 μm was provided on the formed Si layer by vapor deposition. As shown in FIG. 1, the obtained tube material was combined with the same aluminum fin material as in Example 1 and heated at a temperature of 570 ° C. for 3 minutes to be brazed. When the joining state was observed after brazing, a sound fillet was formed between the tube material and the fin material, and buckling was not observed.

Example 9 1 × was formed on the upper and lower flat surfaces of the tube material obtained in Example 1.
Si in an average thickness of 5 μm by vapor deposition in a vacuum of 10 ^-6 Torr
A layer is formed and an average thickness of 0.4 μ is formed on the formed Si layer.
An Ni layer of m 2 and a Zn layer having an average thickness of 0.2 μm were provided. As shown in FIG. 1, the obtained tube material was combined with the same aluminum fin material as in Example 1 and heated at a temperature of 570 ° C. for 3 minutes to be brazed. After brazing, a sound fillet was formed between the tube material and the fin material, and buckling was not observed. The obtained heat exchanger element was subjected to a CASS test for 2 weeks, but no through hole was formed in the tube material.

Example 10 On the upper and lower flat surfaces of the tube material obtained in Example 1, 1 ×
Average thickness by sputtering in a vacuum of 10 ^-6 Torr 1.
A Si layer having a thickness of 5 μm was formed, and a Sn layer having an average thickness of 0.01 μm was provided on the formed Si layer by sputtering. The obtained tube material was combined with the same aluminum fin material as in Example 1 as shown in FIG.
Brazing was performed by heating at the temperature of 3 minutes. After brazing, a sound fillet was formed between the tube material and the fin material, and buckling was not observed. CA of 2 weeks for the obtained heat exchanger element
An SS test was conducted, but no through hole was formed in the tube material.

Example 11 The tube material obtained in Example 1 was cut into a length of 400 mm,
On the upper and lower flat surfaces of these tubes, a Si layer having an average thickness of 5 μm was formed by vapor deposition in a vacuum of 1 × 10 ⁻⁶ Torr. Then, the central part of the obtained Si layer coated tube was 380 m.
Masking m and adding 15 μm S on both ends of the tube.
The i-layer was overlaid and evaporated. As shown in FIG. 3, the obtained tube was combined with the same aluminum fin material as in Example 1 and brazed under the same conditions as in Example 1. After brazing, a sound fillet was formed between the tube and the fin material and between the tube and the header, and no buckling was observed.

Comparative Example 1 1 × was formed on the upper and lower flat surfaces of the tube material obtained in Example 1.
In vacuum of 10 ^-6 Torr, S with an average thickness of 0.4 μm was deposited.
An i-layer was formed. As shown in FIG. 1, the obtained Si layer-covered tube material was combined with the same aluminum fin material as in Example 1 and brazed under the same conditions as in Example 1, but sufficient molten brazing was formed. No sound fillet could be formed between the tube material and the fin material.

Comparative Example 2 1 × was formed on the upper and lower flat surfaces of the tube material obtained in Example 1.
The average thickness is 0 by sputtering in a vacuum of 10 ^-6 Torr.
After forming In of 005 μm, an Si layer having an average thickness of 4 μm was deposited on the In layer by the same sputtering. The obtained metal layer-covered tube material was combined with the same aluminum fin material as in Example 1 as shown in FIG.
Brazing was performed under the same conditions as in Example 1. After brazing, a sound fillet was formed between the tube material and the fin material, but the obtained heat exchanger element was subjected to a CASS test for 2 weeks, which resulted in a lack of sacrificial anode effect. A through hole was created in the tube material.

Comparative Example 3 On the upper and lower flat surfaces of the tube material obtained in Example 1, 1 ×
Average thickness 6 by sputtering in a vacuum of 10 ^-6 Torr
After forming a Zn layer having a thickness of .mu.m, a Si layer having an average thickness of 4 .mu.m was deposited on the Zn layer also by sputtering. The obtained metal layer-covered tube material was combined with the same aluminum fin material as in Example 1 as shown in FIG.
Brazing was performed under the same conditions as in Example 1. After brazing, a sound fillet was formed between the tube material and the fin material, but the heat exchanger element obtained was subjected to a CASS test for 2 weeks, and as a result, the fillet portion was preferentially early. Corroded and fins fell out.

[0033]

As described above, according to the present invention, during brazing, a uniform Si layer for forming a molten braze and a uniform and thin metal layer for forming a sacrificial anode layer can be obtained, and a brazing sheet can be obtained. A uniform and stable brazing joining is possible without using. Particularly, in the aluminum heat exchanger, the bare material can be used as the fin material by forming the Si layer on the tube material, so that the fin material can be thinned and the heat exchanger can be reduced in weight. The formation of the coating layer such as the Si layer can be performed easily and inexpensively.

[Brief description of drawings]

FIG. 1 is a partial perspective view showing an aluminum heat exchanger element in which a flat porous tube and fins are combined.

FIG. 2 is a sectional view of a flat porous tube.

FIG. 3 is a partial cross-sectional side view of a parallel flow heat exchanger.

[Explanation of symbols]

 1 Flat Perforated Tube 2 Fins 3 Flat Surface 4 Flat Surface 5 Covering Layer 6 Header Tube 7 Thick Covering Layer

Claims (8)

[Claims] 1. An aluminum brazing member for forming a molten braze on a joining surface and brazing and joining another aluminum member, wherein the joining surface with the other aluminum member has an average thickness of 0.5 to 100 μm. An aluminum brazing member having a Si layer. 2. The Si layer comprises Si, Ag, Cu, Ga,
Ge, Li, Mg, Re, Sn, Zn, In, Pd, S
e, Au, Be, Ca, Ce, Dy, La, Nd, N
The aluminum brazing member according to claim 1, which is made of at least one element selected from i, Sm, Tb, and Y. 3. Ag, Cu, or above or below the Si layer
Ga, Li, Mg, Re, Sn, Zn, In, Pd, S
e, Au, Be, Ca, Ce, Dy, La, Nd, N
The aluminum brazing member according to claim 1, wherein a metal layer made of one or more of i, Sm, Tb, and Y is laminated and provided. 4. Zn, In, Sn, Ga under the Si layer
The aluminum brazing member according to claim 1, wherein a metal layer made of one or more of the above is provided. 5. The metal layer comprises Zn having an average thickness of 0.1 to 5 μm.
Layer or a metal layer made of Zn and at least one of In, Sn and Ga and having an average thickness of 0.1 to 5 μm, or In and S
The average thickness of one or more of n and Ga is 0.01 to 0.
The aluminum brazing member according to claim 4, which is a metal layer having a thickness of 5 μm. 6. The aluminum brazing member according to claim 5, wherein a pure aluminum layer is interposed between the Si layer and the Zn layer or the metal layer. 7. The aluminum brazing member is a multi-hole flat tube made of aluminum.
The aluminum brazing member described. 8. The aluminum brazing member according to claim 1, wherein the Si layer, the Zn layer and the metal layer are formed by vapor deposition, sputtering or ion plating.