JPH05125472A - Aluminum clad fin material - Google Patents

Abstract

PURPOSE:To provide the clad fin material which is less buckled and deformed at the time of brazing and has excellent strength and electrical conductivity after brazing as the aluminum fin material to be used for heat exchangers of automobiles, such as radiators and heaters. CONSTITUTION:This fin material is constituted by using an aluminum alloy contg. <=0.5wt.% Fe (hereafter described simply as %), <=0.5 Si or further one or >=2 kinds of <=0.3% Mn, <=0.3% Cr, <=0.3% Zr, and <=0.3% Ti or/and one or 2 kinds of 0.5 to 3% Zn, 0.01 to 0.2% In and 0.01 to 0<=.2% Sn and consisting of the balance Al and unavoidable impurities as a core material and cladding an aluminum alloy contg. 0.5 to 7% Si and the balance Al and unavoidable impurities on one or both sides.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an aluminum clad fin material used for heat exchangers for automobiles such as radiators and heaters.

[0002]

2. Description of the Related Art Generally, an aluminum radiator is shown in FIG.
Attach aluminum fins (1) between a number of aluminum tubes (2) as shown in
An aluminum header (3) is provided at the end of the resin tank (4). The aluminum fins, tubes, and headers are joined by brazing using a fluoride-based flux, and then the resin tank is attached by caulking, which is a mechanical joining method.

The aluminum fin material used for this is an aluminum alloy in which 1 to 2 wt% of Zn is added to 3003 alloy (Al-0.15 wt% Cu-1.1 wt% Mn) (hereinafter wt% is abbreviated as%), Alternatively, a plate material having a plate thickness of 0.08 to 0.11 mm obtained by adding Zr or Zn to pure Al is used.

The properties required for a fin material for a radiator are that it does not cause sag (crushing) during brazing, and that it has a predetermined strength after brazing.
Maintaining the structural strength of the core, having a sacrificial anode action,
It protects the tube material from corrosion, has excellent thermal conductivity, and excels in heat exchange performance (heat dissipation performance). Moreover, in brazing using a fluoride, it is necessary that the brazing property is good.

[0005]

In recent years, the aluminization of radiators has been rapidly progressing in Japan as well.
When the plate thickness of the fins is reduced to reduce the weight, the heat dissipation property is deteriorated, and a shift from the fins of the 3003 alloy system to pure Al fins having excellent thermal conductivity is under study. However, simply changing to a fin of pure Al has a problem in strength and has not been adopted yet. On the other hand, it is possible to use a 6XXX-based alloy having excellent thermal conductivity, but Mg as an additive component reacts with F in the flux to reduce the activity of the flux, which may cause brazing failure.

[0006]

As a result of various studies in view of this, the present invention has developed an aluminum clad fin material which is excellent in all aspects such as thermal conductivity, strength, brazing property and sacrificial action.

That is, one of the fin materials of the present invention is Fe 0.5%
Hereinafter, an aluminum alloy containing Si 0.5% or less and the balance Al and unavoidable impurities is used as a core material, and an aluminum alloy containing Si 0.5 to 7% on one or both sides of the core material and the balance Al and unavoidable impurities. It is characterized by clad.

Another one of the fin materials of the present invention is Fe.
0.5% or less, Si 0.5% or less, Mn 0.3% or less, Cr
0.3% or less, Zr 0.3% or less, Ti 0.3% or less 1
Aluminum alloy containing at least one kind or two or more kinds and having the balance Al and inevitable impurities as a core material, and an aluminum alloy containing 0.5 to 7% of Si on one or both sides of the core material and having the balance Al and inevitable impurities. It is characterized by being clad.

Another one of the fin materials of the present invention is Fe.
0.5% or less, Si 0.5% or less, Zn 0.5 to 3%, In0.
An aluminum alloy containing 01 to 0.2% and Sn 0.01 to 0.2% of one kind or two or more kinds and the balance Al and unavoidable impurities is used as a core material, and Si 0.5 is provided on one side or both sides of the core material.
It is characterized by clad with an aluminum alloy containing ˜7% and the balance Al and unavoidable impurities.

Furthermore, another one of the fin materials of the present invention is Fe.
0.5% or less, Si 0 %% or less, Mn 0.3% or less, Cr
0.3% or less, Zr 0.3% or less, Ti 0.3% or less 1
Or two or more, and Zn 0.5 to 3%, In 0.01 to
0.2%, Sn 0.01 to 0.2%, one or more of them, and an aluminum alloy containing the balance Al and unavoidable impurities as a core material, and Si 0.5 to 7 on one or both sides of the core material.
%, And an aluminum alloy containing the balance Al and unavoidable impurities is clad.

[0011]

In the present invention, the composition of the core material is limited as described above for the following reason.

Fe and Si are usually contained as impurities in the Al ingot. However, the reason why Fe is limited to 0.5% or less is that if it is contained more than that, sag during brazing becomes remarkable. Further, the reason why Si is limited to 0.5% or less is that if it is contained more than this, not only the sag at the time of brazing becomes remarkable but also the heat conduction performance is deteriorated.

Mn, Cr, Zr, and Ti are added to improve heat resistance (sag resistance) and strength. However, the content of Mn, Cr, Zr, and Ti is limited to 0.3% or less. This is because the thermal conductivity is reduced. Therefore, in each case, it is desirable to add about 0.1%, and in the case of compound addition, it is desirable to keep the total to about 0.3%.

Zn, In and Sn are added in order to give a sacrificial anode action, and a noble aluminum alloy which replaces the 3003 alloy, such as Al-1.1% Mn-, is added to the tube material.
It is not necessary to add it when using a 0.5% Cu alloy.
Therefore, the addition amount of Zn is 0.5 to 3%, In 0.01 to 0.2%,
Sn is limited to 0.01 to 0.2% because if it is less than the lower limit, the sacrificial action is not exhibited, and if it exceeds the upper limit, the effect is saturated.

Next, the reason why the composition of the skin material clad with the core material is limited as described above is as follows. Si is added to improve the strength after brazing, and the amount added is limited to 0.5 to 7%. If the amount is less than the lower limit, the strength cannot be improved after brazing, and if it exceeds the upper limit, brazing is performed. This is because it sometimes melts and sag becomes remarkable as the fin material.

Generally, the brazing fin material in which the brazing material is clad on both sides of the core material has a Si content of 7 to 13%, and the brazing material layer is melted for brazing. Since the brazing material on the tube side melts, it is not necessary to melt the fin material.

The Mg content in the skin material should be minimized from the standpoint of brazing property, and the Cu content in the skin material should also be minimized because it will impair the sacrificial action. Further, Fe, Mn, Cr, Zr, and Ti may be added to the skin material for the purpose of improving strength, and Zn, In, and Sn may be added for the purpose of improving sacrificial action.

The skin material may be a single-sided clad or a double-sided clad of the core material. However, when the fin plate thickness is 0.1 mm or less, Si in the skin material is sufficiently diffused into the core material by brazing and heating. Good. The clad rate may be 5 to 20%.

[0019]

EXAMPLES The present invention will be described below with reference to examples. Using the core material having the composition shown in Table 1 and the skin material shown in Table 2, the skin material clad ratio
A 10% single-sided clad material was manufactured by a conventional method. That is, after the die casting, the core material was faced to a thickness of 45 mm and subjected to a soaking treatment at 500 ° C. for 3 hours. On the other hand, the skin material was chamfered, hot-rolled at 500 ° C., and then cold-rolled to a thickness of 5 mm. These core materials and skin materials are overlaid and hot compression bonding is performed at 500 ° C.
Used as a clad material. This was cold-rolled, intermediate-annealed, and finally cold-rolled to produce a 0.1 mm thick H14 tempered aluminum clad fin material. In addition, 3003 in the conventional example of Table 1
Indicates a 3003 alloy, and 1070 indicates a 1070 alloy (Al 99.70% or more).

With respect to these fin materials, the strength after brazing, the electric conductivity, the brazing property, and the sag resistance were examined, and the corrosion resistance of the combined tube was examined. The results are shown in Table 3.

The strength and conductivity were brazed and heated in N ₂ gas at 600 ° C., and the tensile strength and conductivity (% IAC) after heating were measured.
S) was measured. As shown in Fig. 1, the brazing and sag resistance is 40% on one side of the core material (3003 alloy + 0.5% Cu alloy).
Thickness of 45 alloy (Al-10% Si) brazing material clad
A tube material (2) in which a brazing material of 0.4 mm is brazed to the outside by electric resistance welding in a flat shape,
The corrugated fin material (1) was combined to form a mini-core, and a fluoride flux consisting of KAlF ₄ and K ₂ AlF ₅ was used at a concentration of 5%, and the temperature was 600 ° C in N ₂ gas.
The brazing heating was performed, and the presence or absence of the sag of the fin and the joining rate of the fin during the brazing heating were examined. The total number of fins tested was 100. Corrosion resistance of the above mini core is 3
The maximum pitting depth of the tube material was examined by subjecting it to a Cass test (JIS 8681) for 00 hours.

[0022]

[Table 1]

[0023]

[Table 2]

[0024]

[Table 3]

As is clear from Table 3, the fin material of the present invention has a strength after brazing of 80 N / mm ² or more and an electrical conductivity of 44% IA.
It shows that it is CS or more, there is no sag due to brazing, and it has good corrosion resistance. On the other hand, in the comparative fin material in which the composition of the core material or the skin material is out of the composition range of the present invention, No.
Nos. 19 and 24 are inferior in strength, Nos. 21, 22, and 23 are inferior in conductivity, and Nos. 18, 20, and 21 are inferior in brazing property because sag occurs during brazing.

[0026]

As described above, according to the present invention, a clad fin material having less buckling deformation during brazing, excellent strength and conductivity after brazing, and good corrosion resistance can be obtained, and the radiator fin can be thinned. This makes it possible to reduce the weight of the radiator and improve the heat dissipation characteristics, which is a significant industrial effect.

[Brief description of drawings]

FIG. 1 is a perspective view showing a structure of a brazing test core.

FIG. 2 is a perspective view showing a structure of a radiator.

[Explanation of symbols]

 1 fin 2 tube 3 header 4 tank

Claims (4)

[Claims] 1. An aluminum alloy containing 0.5 wt% or less of Fe and 0.5 wt% or less of Si and the balance Al and inevitable impurities is used as a core material.
An aluminum clad fin material, characterized by including an aluminum alloy containing 7 wt% and the balance Al and unavoidable impurities. 2. Fe 0.5 wt% or less, Si 0.5 wt% or less, Mn 0.3 wt% or less, Cr 0.3 wt% or less, Zr 0.3 wt.
% Or less, and Ti 0.3 wt% or less, one or two or more kinds, and the balance is aluminum alloy consisting of Al and unavoidable impurities as a core material, and Si 0.5 to 7 on one side or both sides of the core material.
An aluminum clad fin material comprising an aluminum alloy containing wt% and the balance being Al and unavoidable impurities. 3. Fe 0.5 wt% or less, Si 0.5 wt% or less, Zn 0.5-3 wt%, In 0.01-0.2 wt%, Sn 0.01
~ 0.2 wt% of one or more of 0.2 wt%, the remaining aluminum and aluminum alloy consisting of inevitable impurities as the core material,
An aluminum clad fin material, characterized in that one or both sides of the core material is clad with an aluminum alloy containing 0.5 to 7 wt% of Si and the balance Al and unavoidable impurities. 4. Fe 0.5 wt% or less, Si 0.5 wt% or less, Mn 0.3 wt% or less, Cr 0.3 wt% or less, Zr 0.3 wt.
% Or less, one or more of 0.3 wt% Ti, and 0.5 to 3 wt% Zn, 0.01 to 0.2 wt% In, Sn 0.01 to
An aluminum alloy containing 0.2 wt% of one or two or more and the balance Al and inevitable impurities is used as the core material, and Si 0.5 to 7 wt% is included on one side or both sides of the core material, and the balance Al is unavoidable. An aluminum clad fin material, characterized by clad with an aluminum alloy made of impurities.