JP3014413B2 - Aluminum fin material - Google Patents

Description

The present invention relates to an aluminum fin material, and more particularly to a fin material for an aluminum heat exchanger for automobiles, which has a heat radiation property,
Excellent sacrificial anode action and strength, thinner material of heat exchanger,
That is, it is possible to reduce the weight of the core and improve the heat dissipation.

[Conventional technology]

Serpentine type and parallel flow type are known as aluminum heat exchangers for automobiles, for example, condensers. As shown in FIG. 1, the serpent type mold is formed by bending an extruded tube (1) in a meandering shape, attaching a corrugated fin (2) made of a brazing sheet between the tubes (1), and a union (9) at both ends of the tube (1). Is attached. In the parallel flow type, as shown in FIG. 2, the extruded tube (1) is cut short and arranged in a large number in parallel, header tubes (3) are provided on both sides, and a corrugated brazing sheet is formed between the extruded tubes (1). Huin (2)
And a union (4) is attached to one end of the header tube (3). These are fins as shown in the figure,
Combine extrusion tube, header tube, union, etc.
Brazing is performed by heating to a temperature of about 0 ° C.

The fin material is A-Mn based 3003 alloy or
A alloy with Zn, Sn, In, etc. added as core material, A
-A brazing sheet with a thickness of 0.1 to 0.2 mm clad with a Si-based brazing material is used, and it is necessary that the brazing sheet has appropriate strength for processing at room temperature, such as corrugation processing and assembly with an extruded tube. Usually, a hard material having a strength of H14 to H16, that is, 14 to 18 kgf / mm ² is used. However, since it is exposed to a high temperature of about 600 ° C during brazing heating,
Due to the restraint of the tube material and the steel jig, the thinnest fin material is deformed, and core deformation or brazing failure may occur. Therefore, the fin must have high-temperature strength and sag resistance, and various measures have been taken to prevent the brazing material clad on the fin surface from diffusing into the core material.

[Problems to be solved by the invention]

In recent years, there has been a strong need for a compact and high performance (improved heat radiation characteristic) of an automotive exchanger, and a thinner fin material, improved thermal conductivity, and the like have been desired. A fin material having a 3003 alloy as a core material can be made thinner from the viewpoint of strength. However, when thinning, heat dissipation is reduced due to a decrease in fin cross-sectional area, and therefore, it is necessary to improve heat conductivity.

However, the fin material with 3003 alloy as the core material has a high thermal conductivity of 38% IACS and a lower position in the aluminum alloy due to the solid solubility of added Mn (1.1 wt%) in the alloy. It hinders its use and has problems with its use.

[Means for solving the problem]

In view of this, as a result of various studies, the present invention has achieved a balance between strength and thermal conductivity in place of fins using 3003 alloy as the core material, and furthermore, has a high temperature deformation during brazing, resistance to sag, sacrificial action, etc. Aluminum fin material was developed.

That is, one of the present inventions is a fin material comprising a brazing sheet clad with an A-Si alloy brazing material on both surfaces of a core material, wherein the core material has a Si content of 0.3 wt% or less (hereinafter, wt% is abbreviated as%), Fe0. Contains 3 to 1.5%, Mg 0.05 to 0.4%, balance A
And an A alloy comprising inevitable impurities.

Another aspect of the present invention is a fin material composed of a brazing sheet in which an A-Si alloy brazing material is clad on both surfaces of a core material, wherein the core material has 0.3% or less of Si, 0.3 to 1.5% of Fe, and 0.3% of Mg. 0
An alloy containing 5 to 0.4% and Zr of 0.03 to 0.3% and containing the balance A and inevitable impurities is used.

Another aspect of the present invention is a fin material comprising a brazing sheet in which an A-Si alloy brazing material is clad on both surfaces of a core material, wherein the core material has a Si content of 0.3% or less, a Fe 0.3% to 1.5%,
g 0.05-0.4%, Zn 0.6-3.0%, In 0.01-0.1
% And Sn in the range of 0.01 to 0.1%, characterized by using an alloy A containing at least one of them and the balance of A and unavoidable impurities.

Still another aspect of the present invention is a fin material comprising a brazing sheet in which an A-Si alloy brazing material is clad on both surfaces of a core material, wherein the core material has a Si content of 0.3% or less, a Fe 0.3% to 1.5%,
g 0.05-0.4%, Zr 0.03-0.3%, Zn 0.6-3.0
%, In 0.01-0.1%, Sn 0.01-0.1%
It is characterized by using an A alloy containing the seed or two or more kinds and the balance of A and unavoidable impurities.

(Operation)

The present invention improves heat dissipation, sacrificial anode function, strength, etc. by using the above-mentioned A alloy in a fin material comprising a brazing sheet in which an A-Si alloy brazing material is clad on both surfaces of a core material. The reason for limiting the composition of the A alloy as described above is as follows.

The reason why the Si content is limited to 0.3% or less is that if added in excess of 0.3%, the phenomenon in which the brazing material clad is diffused to the core material side during brazing becomes remarkable, and the brazing property is reduced. .

The reason that the Fe content is limited to 0.3 to 1.5% is that Fe has a low solid solubility in A and improves strength without lowering thermal conductivity, but has no effect when it is less than 0.3% and exceeds 1.5%. This not only saturates the effect but also lowers sag resistance.

The reason why the Mg content is limited to 0.05 to 0.4% is that it reacts with solid solution in A and Si diffused from the brazing material to form a compound (Mg ₂ S
Although the material strength is improved by the precipitation of i), there is no effect at less than 0.05%, and when it exceeds 0.4%, the brazing property decreases,
In particular, when a fluoride-based flux is used, an Mg-F compound is formed, and the effect of the flux to destroy an oxide film is significantly reduced.

Zr has the effect of improving the strength and sag resistance of the fin and preventing high-temperature deformation. Thus, the Zr content is 0.03--0.
The reason for limiting it to 3% is that if it is less than 0.03% there is no effect, 0.3%
If the ratio exceeds the limit, plastic workability and thermal conductivity are reduced. Like Zr, Cr, T is used to improve strength and sag resistance.
The addition of i, Mn is effective, and any one or more of Cr, Ti, and Mn can be used in a range of 0.03 to 0.3 as long as the thermal conductivity is not significantly reduced.
3% may be added.

The addition of one or more of Zn in the range of 0.6-3.0%, In0.01-0.1%, and Sn0.01-0.1% is because the potential of the fin material is base and the sacrificial anode action However, if both are less than the lower limit, there is no effect. If the upper limit is exceeded, the plastic workability and the thermal conductivity are reduced.

As a brazing material clad on both sides of the core material, a normal A
-Si alloys, for example 4343, 4045 or Zn, Sn, I
An alloy to which n or the like is added is used, and the cladding ratio is about 5 to 15%.

The present invention utilizes the Si diffusion phenomenon from the brazing material during brazing heating, reacts with Mg contained in the core material, and precipitates Mg ₂ Si during cooling after brazing to age harden. . The diffusion depth from the brazing material to the core material side is 100 to 200 μm by ordinary brazing heating, and if the cladding fin is about 0.2 mm (200 μm), the strength of the central portion of the core material can be sufficiently improved.

This can be used for brazing sheets having a thickness of 0.2 to 0.6 mm other than fins, and is effective for improving the strength after brazing.

Examples Examples of the present invention will be described below.

Using an A alloy having the composition shown in Table 1 as a core material and an A-10% Si alloy as a brazing material as a skin material, a brazing sheet for fins having a thickness of 0.15 mm was produced by the following method.

After melting and casting the core material and brazing material by the usual method,
The core material was homogenized at 520 ° C. for 3 hours, and the brazing material was hot-rolled at 500 ° C. to obtain a cladding material thickness (cladding ratio of 10%). In this way, the brazing material is overlaid on both sides of the core material,
After a thickness of 5 mm was formed by hot rolling at 500 ° C., a plate having a thickness of 0.2 mm was formed by cold rolling. This was subjected to intermediate annealing at 380 ° C. for 2 hours, and then final cold rolling was performed to obtain a 0.15 mm thick bracing sheet for fins.

The brazing sheet for fins thus prepared was brazed and heated in the air at 600 ° C. for 10 minutes, and its tensile strength and dielectric constant were measured. In addition, the brazing sheet for fins is corrugated to 22 mm wide, 18 mm high, and 4 mm pitch,
This was combined with a 1050 alloy extruded tube (height: 5 mm, width: 22 mm, wall thickness: 0.6 mm) sprayed with Zn at a rate of 10 g / m ² on the surface to assemble the serpentine type condenser shown in FIG.
Fluoride-based flux (mixture of KAF ₄ and K ₃ AF ₆ ) is applied at 3% concentration (dispersed in water), dried, and dried in N ₂ atmosphere for 60%.
Brazing was performed by heating to 0 ° C., and brazing properties and corrosion resistance of the produced capacitors were examined. Table 2 shows the results.

For brazing properties, check the joining condition and fin buckling,
If both were good, it was regarded as good, and if either or both were inferior, it was regarded as bad. Corrosion resistance is 200 hours CASS test (JIS H
8681), and the pit depth generated in the extruded tube was measured by the depth of focus method.

As is clear from Tables 1 and 2, Examples Nos. 1 to
No. 15 shows that the tensile strength after brazing is 13 kgf / mm ² or more and the electrical conductivity is 40% IACS or more, and that the brazing property and the sacrificial action are excellent.

On the other hand, Comparative Example No. 16 having a small Fe content and Comparative Example No. 18 having a small Mg content have low strength, Comparative Example No. 17 having a large Fe content, and Comparative Example No. 19 having a large Mg content. Then brazing property is bad. Comparative Examples No. 20 to 22 with high Zn, In and Sn contents
In any case, there is a problem that self-corrosion of the fin is severe.

〔The invention's effect〕

According to the present invention, the fin strength and the sacrificial action after brazing are equal to or higher than those of the conventional material, the conductivity (heat dissipation) is excellent, and a remarkable effect that the performance of the heat exchanger can be significantly improved is exhibited. It is.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an example of a serpentine type condenser, and FIG. 2 is a front view showing an example of a parallel flow type condenser. 1 ... Extrusion tube 2 ... Fin 3 ... Header pipe 4 ... Union

Claims (4)

(57) [Claims] 1. A fin material comprising a brazing sheet in which an A-Si alloy brazing material is clad on both surfaces of a core material, wherein the core material has 0.3% by weight or less of Si, 0.3 to 1.5% by weight of Fe, and 0.05 to 0% of Mg. .
A containing 4wt%, balance A and unavoidable impurities
An aluminum fin material characterized by using an alloy. 2. A fin material comprising a brazing sheet in which an A-Si alloy brazing material is clad on both sides of a core material, wherein the core material contains 0.3% by weight or less of Si, 0.3 to 1.5% by weight of Fe, and 0.05% by weight of Mg.
An aluminum fin material comprising an A alloy containing 0.4 wt% and Zr of 0.03 to 0.3 wt%, the balance being A and unavoidable impurities. 3. A fin material comprising a brazing sheet in which an A-Si alloy brazing material is clad on both sides of a core material, wherein the core material contains 0.3% by weight or less of Si, 0.3 to 1.5% by weight of Fe, and 0.05% by weight of Mg.
0.4wt%, Zn0.6 ~ 3.0wt%, In0.01 ~ 0.1wt
%, Sn in the range of 0.01 to 0.1 wt%, using an A alloy containing one or more of them, the balance being A and unavoidable impurities. 4. A fin material comprising a brazing sheet in which an A-Si alloy brazing material is clad on both sides of a core material, wherein the core material contains 0.3% by weight or less of Si, 0.3 to 1.5% by weight of Fe, and 0.05 to 0.05% by weight of Mg.
Contains 0.4wt%, Zr 0.03-0.3wt%, Zn 0.6-3.0wt
%, In 0.01 to 0.1 wt%, and Sn 0.01 to 0.1 wt%, characterized by using an A alloy containing at least one of them and the balance of A and inevitable impurities. Aluminum fin material.