JP2813490B2 - Aluminum brazing sheet - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an aluminum brazing sheet used for a heat exchanger of an automobile, and more particularly to an aluminum brazing sheet used as a material for a pipe or the like forming a refrigerant passage of the heat exchanger. Things.

[0002]

2. Description of the Related Art Radiators, heat exchangers for automobiles,
There are various types such as a car air conditioner, an intercooler, and an oil cooler. For example, a radiator having a structure as shown in FIG. 1 is used. In FIG. 1, 1 is a tube, 2 is a fin, 3 is a header, and 4 is a tank.
The tube 1, the fins 2 and the header 3 are made of an aluminum material, and the tank 4 is often made of a resin. The tube 1, the fins 2, and the header 3 are integrated by joining by brazing using a fluoride-based flux, and a resin tank is attached thereto by mechanical joining (caulking) to manufacture a radiator. The tube material is an Al-Mn alloy 300
Al alloy on the fin side (atmosphere side) of the core material
Three layers in which a brazing material such as a 4343 alloy or a 4045 alloy which is an Si-based alloy is clad, and a sacrificial anode material such as an Al-Zn-based alloy or an Al-Zn-Mg-based alloy is clad on the other surface (the refrigerant side). A flat tube made of aluminum brazing sheet having a structure by electric resistance welding and roll forming is used. Its plate thickness is 0.3 to 0.4 mm. As the fin material, a material obtained by adding Zn to the 3003 alloy to have a sacrificial anode effect is used, and the thickness thereof is 0.0
8 to 0.11 mm. As the header material, an aluminum brazing sheet is used in which a brazing material is clad on the atmosphere side of a 3003 alloy core material and a sacrificial anode material is clad on the refrigerant side, similarly to the tube material, and its thickness is 1 to 2 mm. It is.

[0003] In recent years, there has been an increasing demand for weight reduction of automobiles, and in order to cope with such demands, weight reduction of automobile heat exchangers is also required. Therefore, thinning of each member is being studied, and an aluminum-brazing sheet is also made of Al-Mn-Cu-based alloy, Al-Si-M
The use of alloys having higher strength and higher corrosion resistance than conventional Al-Mn-based alloys, such as g-based alloys and Al-Si-Mg-Mn-Cu-based alloys, has been promoted.

[0004]

However, in the brazing using a fluoride-based flux, the M
The brazing property of an aluminum brazing sheet having an alloy containing g as a core material is unstable. For example, for a brazing sheet used as a tube material, 0.3 wt%
When the above Mg is added, Mg diffuses from the core material into the brazing material during brazing and F and Mg in the flux applied at the time of brazing react with each other to form an MgF compound on the surface of the tube material. The brazing property between the material and the fin is significantly deteriorated. Similar brazing failure may also occur at the joint between the header and the tube. When the thickness of the tube or fin is small, Mg not only causes the brazing failure as described above, but also diffuses from the material to the material surface during brazing to reduce the amount of Mg in the core material. Significant reduction causes a decrease in strength after brazing.

[0005]

SUMMARY OF THE INVENTION The present invention provides an aluminum brazing sheet particularly used as a thin-walled radiator tube material, which prevents the brazing property from being reduced due to the diffusion of Mg from a core material into a brazing material, and furthermore, a brazing material. An aluminum brazing sheet having high strength after being applied has been developed, and the invention according to claim 1 has an Al-Si alloy brazing material on one surface of a core material and an Al-Zn alloy alloy on the other surface, or In an aluminum brazing sheet clad with a sacrificial anode material such as an Al-Zn-Mg alloy, the core material has a two-layer structure, and the brazing material side of the core material has Mn0.
5 to 1.5 wt%, Cu 0.2 to 1.0 wt%, Si
An Al alloy containing 0.3 to 1.0 wt% and 0.05 to 0.2 wt% of Mg, the balance being Al and unavoidable impurities, and the sacrificial anode material side having 0.3 to 1.0 wt% of Si, Mg
The aluminum brazing sheet according to claim 2, wherein the aluminum brazing sheet contains 0.2 to 1.0 wt% and 0.3 to 1.0 wt% of Cu, and is an Al alloy including a balance of Al and unavoidable impurities. The invention uses Al-S on one side of the core material.
In an aluminum brazing sheet in which a brazing material of an i-based alloy is clad with a sacrificial anode material such as an Al-Zn-based alloy or an Al-Zn-Mg-based alloy on the other surface, the core material has a two-layer structure. Mn 0.5-1.5w
t%, Cu 0.2-1.0 wt%, Si 0.3-1.0
wt.%, 0.05 to 0.2 wt.% Mg, and 0.05 to 0.3 wt.% each of one or more of Cr, Zr, and Ti. An Al alloy composed of impurities, and the sacrificial anode material side is made of Si0.
3 to 1.0 wt%, Mg 0.2 to 1.0 wt%, Cu
An aluminum brazing sheet comprising 0.3 to 1.0 wt% and an Al alloy comprising the balance of Al and unavoidable impurities. In an aluminum brazing sheet in which a brazing material of a Si-based alloy is clad with a sacrificial anode material such as an Al-Zn-based alloy or an Al-Zn-Mg-based alloy on the other surface, the core material has a two-layer structure. 0.5 to 1.5 wt% Mn, 0.2 to 1.0 watts Cu
t%, Si 0.3-1.0 wt%, Mg 0.05-0.
An Al alloy containing 2 wt% , the balance being Al and unavoidable impurities, with the sacrificial anode material side being Si 0.3-1.0 w
t%, Mg 0.2-1.0 wt%, Cu 0.3-1.0
Al alloy containing 0.05% to 0.3% by weight of each of Mn, Cr, Zr and Ti, and the balance of Al and unavoidable impurities. An aluminum brazing sheet according to claim 4, wherein the core material has Al-
An aluminum brazing sheet in which a brazing material of a Si-based alloy is clad with a sacrificial anode material such as an Al-Zn-based alloy or an Al-Zn-Mg-based alloy on the other surface, the core material has a two-layer structure, Mn 0.5-1.5
wt%, Cu 0.2-1.0 wt%, Si 0.3-1.
0 wt%, Mg 0.05-0.2 wt%, and further contains 0.05-0.3 wt% of one or more of Cr, Zr, and Ti, respectively, and the balance with Al is inevitable. Al alloy composed of impurities and Si on the sacrificial anode material side
0.3-1.0 wt%, Mg 0.2-1.0 wt%, C
u 0.3-1.0 wt%, each further 0.05
An aluminum brazing sheet characterized in that it is an Al alloy containing at least one of Mn, Cr, Zr, and Ti in an amount of 0.3% by weight and the balance being Al and unavoidable impurities.

[0006]

In the present invention, the core material has a two-layer structure, and the material on the brazing material side (hereinafter referred to as "A material") is made of a material containing less Mg to reduce the diffusion of Mg into the brazing material. Core material on the sacrificial anode material side (hereinafter referred to as material B)
Is a brazing sheet having high strength and good corrosion resistance using a material having a high Mg content.

The reasons for adding the additional elements in the materials A and B and the reasons for limiting the amounts added will be described below. In material A,
Mn is added to improve strength and corrosion resistance, and the addition amount is set to 0.5 to 1.5 wt% (hereinafter abbreviated as%). If the amount exceeds the above range, the plastic workability decreases. Cu is added to improve strength and corrosion resistance, and the addition amount is 0.2 to
The effect of 1.0% is less than 0.2%, and no effect is obtained.
%, The plastic workability decreases. Si forms a compound consisting of Mg and Mg ₂ Si, and is effective in improving the strength after brazing. If it is less than 0.3%, the effect is small.
If it exceeds 0%, the corrosion resistance and plastic workability deteriorate. In the present invention, the Mg in the B material is diffused into the A material at the time of brazing heat, thereby forming Si and Mg ₂ Si in the A material to improve the strength. Mg is effective in improving the strength .
If the content is less than 05%, the effect cannot be obtained. If the content exceeds 0.2%, it diffuses to the brazing material side and lowers the brazing property. Therefore , the content is 0.05 to 0.2% . Cr, Z
Both r and Ti are effective in improving the strength, but each is less effective if less than 0.05%, and if more than 0.3%, a huge compound is formed and the plastic workability is reduced. Fe is preferably added in the amount of impurities of the 3003 alloy, but the smaller the amount, the better the corrosion resistance. In material B, Si is Mg and Mg
To form a ₂ Si becomes compound is effective in improving the strength after brazing. The reason why the addition amount is limited to 0.3 to 1.0% is that if it is less than 0.3%, there is no effect, and if it exceeds 1.0%, the corrosion resistance decreases. Mg forms a compound consisting of Si and Mg ₂ Si, and is effective in improving the strength after brazing. The reason why the addition amount is limited to 0.2 to 1.0% is that if it is less than 0.2%, there is no effect, and if it exceeds 1.0%, the corrosion resistance decreases. Cu is effective in improving strength and corrosion resistance.
If it is less than 0.3%, the effect is small, and if it exceeds 1.0%, the plastic workability deteriorates. All of Mn, Cr, Zr, and Ti are effective in improving the strength. However, if less than 0.05%, there is no effect, and if more than 0.3%, the plastic workability decreases. Fe is good to add about 3003 alloy impurities,
The smaller the amount, the better the corrosion resistance.

In the aluminum brazing sheet of the present invention, the cladding ratio of the brazing material and the sacrificial anode material is 3 to 1 respectively.
About 5% is appropriate, and the clad ratio of the A material and the B material of the core material does not need to be particularly limited. However, when emphasis is placed on brazing properties and external corrosion resistance, the ratio of the A material is increased and the strength is increased. When importance is attached, it is preferable to increase the ratio of the B material. Further, since Cu is added to the B material, Cu may diffuse in the direction of the sacrificial anode material at the time of brazing addition heat, and may reduce the potential lowering effect of Zn and Mg in the sacrificial anode material. Therefore, as the sacrificial anode material, it is preferable to use a sufficiently potential base alloy containing about 1.5% and about 0.5% of Zn and Mg, respectively.

[0009]

EXAMPLES Sixteen kinds of brazing filler metal core materials, fourteen sacrificial anode material core materials and 3003 alloy shown in Tables 1 and 2 were cast by die casting, and both surfaces were ground to a thickness of 20 mm. The brazing material is 4343 alloy, and the sacrificial anode material is Al-1.5% Zn.
Using a -0.5% Mg alloy, each was cast in the same manner as the core material, and after face milling, was hot-rolled to a thickness of 5 mm. Four sheets of a brazing material, a brazing material-side core material, a sacrificial anode material-side core material, and a sacrificial anode material were stacked in this order, and hot-rolled at 500 ° C. to form a four-layer clad material. Thereafter, it was cold-rolled to a thickness of 0.35 mm, subjected to intermediate annealing at 330 ° C. for 2 hours, and finally cold-rolled to a thickness of 0.25 mm to obtain a sample of H14 material. For these samples, the strength, brazing properties, and corrosion resistance were measured by the following methods. After heat of 600 ° C × 10min.
After cooling at a cooling rate of ° C./min., And then allowed to stand at room temperature for 4 days, the tensile strength was measured. Brazing property A corrugated 0.13 mm thick fin material of 3003 alloy and this sample were combined as shown in FIG. 2 to form a core, which was immersed in a 3% fluoride aqueous flux solution. The flux was applied, dried at 200 ° C., and then heated in an inert gas at 600 ° C. for 3 min. To measure the fin bonding rate. Corrosion resistance Atmospheric side: Using the above-mentioned brazing additional heat core, sealing the sacrificial anode material side and the end face, and conducting a corrosion test of CAS 300Hr,
The maximum pit depth generated in the sample was measured. Refrigerant side: After applying the same brazing heat as the strength measurement sample, the brazing material side and the end face are sealed and Cl ^- 195 ppm, F
A cyclic immersion test was conducted for 3 months in high-temperature water at 88 ° C. containing 30 ppm of e ³⁺ , 60 ppm of SO ₄ ²⁺ , and 1 ppm of Cu ²⁺ for 8 months at room temperature and 16 hours at room temperature, and the maximum pit depth generated in the sample was measured. Tables 3 and 4 show the above measurement results.

[0010]

[Table 1]

[0011]

[Table 2]

[0012]

[Table 3]

[0013]

[Table 4]

As is clear from Tables 3 and 4, the present invention N
o. Nos. 1 to 22 have a strength after brazing of 17 kgf / mm ² or more and have a core of 3003 alloy. Higher than 32,
The joining rate is excellent at 90% or more, and the corrosion resistance is also good. In contrast, Comparative Example No. 23, 24, 26, 27, 28, 29
Is low in strength, and Comparative Example No. No. 25 has inferior brazing properties, and all have problems. In Comparative Example No. 1 in which the core was a single layer. 3
For 0 and 31, the former has low strength, the latter has poor brazing properties,
Poor corrosion resistance on the atmosphere side. Further, in the conventional example in which the core material is a 3003 alloy single layer, 32 has low strength.

[0015]

As described above, according to the present invention, the strength after brazing is high, and the corrosion resistance on both the air side and the refrigerant side is good.
Further, an aluminum brazing sheet having good brazing properties can be obtained, and the thickness of the heat exchanger member can be reduced, which has a remarkable effect on reducing the weight of an automobile.

[Brief description of the drawings]

FIG. 1 is an explanatory view showing the structure of a radiator for an automobile.

FIG. 2 is a view showing a brazing-added heat core for determining the brazing property of an aluminum brazing sheet.

[Explanation of symbols]

 1 Tube 2 Fin 3 Header 4 Tank 5 Tube material

Claims (4)

(57) [Claims] 1. A brazing material of an Al—Si alloy on one surface of a core material and an Al—Zn alloy or Al—Zn—M on another surface.
In an aluminum brazing sheet clad with a sacrificial anode material such as a g-based alloy, the core material has a two-layer structure, and the brazing material side of the core material has Mn of 0.5 to 1.5 wt%, Cu 0.2
~1.0wt%, Si0.3~1.0wt%, Mg 0 .
An Al alloy containing 0.5 to 0.2 wt% , the balance being Al and unavoidable impurities, and a sacrificial anode material side of Si0.3
To 1.0 wt%, Mg 0.2 to 1.0 wt%, Cu0.
An aluminum brazing sheet comprising 3 to 1.0 wt%, and an Al alloy comprising the balance of Al and inevitable impurities. 2. An Al—Si alloy brazing material on one side of the core material and an Al—Zn alloy or Al—Zn—M on the other side.
In an aluminum brazing sheet clad with a sacrificial anode material such as a g-based alloy, the core material has a two-layer structure, and the brazing material side of the core material has Mn of 0.5 to 1.5 wt%, Cu 0.2
~1.0wt%, Si0.3~1.0wt%, Mg 0 .
0.05 to 0.2 wt% , each of which contains 0.05 to 0.2 wt%.
0.3 wt% of one or more of Cr, Zr and Ti
And an Al alloy containing the remaining Al and unavoidable impurities.
%, Mg 0.2-1.0 wt%, Cu 0.3-1.0 w
A containing t% and the balance of Al and unavoidable impurities
An aluminum brazing sheet, which is made of a 1 alloy. 3. An Al—Si alloy brazing material on one side of the core material and an Al—Zn alloy or Al—Zn—M on the other side.
In an aluminum brazing sheet clad with a sacrificial anode material such as a g-based alloy, the core material has a two-layer structure, and the brazing material side of the core material has Mn of 0.5 to 1.5 wt%, Cu 0.2
~1.0wt%, Si0.3~1.0wt%, Mg 0 .
An Al alloy containing 0.5 to 0.2 wt% , the balance being Al and unavoidable impurities, and a sacrificial anode material side of Si0.3
To 1.0 wt%, Mg 0.2 to 1.0 wt%, Cu0.
3 to 1.0 wt%, each of which is 0.05 to 0.1 wt%.
An aluminum brazing sheet comprising an Al alloy containing 3 wt% of Mn, Cr, Zr and Ti, or one or more of them, and the balance being Al and unavoidable impurities. 4. A brazing material of an Al—Si alloy on one surface of a core material and an Al—Zn alloy or Al—Zn—M on another surface.
In an aluminum brazing sheet clad with a sacrificial anode material such as a g-based alloy, the core material has a two-layer structure, and the brazing material side of the core material has Mn of 0.5 to 1.5 wt%, Cu 0.2
To 1.0 wt%, Si 0.3 to 1.0 Wt%, Mg 0.
0.05 to 0.2 wt% , each of which contains 0.05 to 0.2 wt%.
0.3 wt% of one or more of Cr, Zr and Ti
And an Al alloy containing the remaining Al and unavoidable impurities.
%, Mg 0.2-1.0 wt%, Cu 0.3-1.0 w
t%, and further each of 0.05 to 0.3 wt% of M
An aluminum brazing sheet comprising one or more of n, Cr, Zr, and Ti, and an Al alloy comprising the balance of Al and inevitable impurities.