JPH0472031A - Aluminum fin material for automobile heat exchanger - Google Patents

Abstract

PURPOSE:To obtain an Al allay having excellent heat conductivity as a fin material for an automobile heat exchanger and furthermore excellent in strength at the time of thinning by adding specified allay elements to Al. CONSTITUTION:As a fin material for an automobile heat exchanger, an Al allay contg., by weight, 0.2 to 1.0% Si, 0.3 to 1.5% Fe and 0.05 to 0.5% Mg, or furthermore contg. 0.03 to 0.3% Zr or one or >= two kinds among 0.5 to 3.0% Zn, 0.01 to 0.l% In and 0.01 to 0.1% Sn each independently or compositely and the balance Al is used. The fin material made of the Al allay more thinnable than the conventional one and excellent in heat conductivity can be obtd.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an aluminum fin material used in a heat exchanger for an automobile.

[Conventional technology]

As shown in FIG. 1, an automobile heat exchanger is manufactured by joining an electric resistance welded tube made of a plating sheet with a brazing material on the outside, fin material, helder material, etc. in a brazing phase.

This fin material requires appropriate strength to be processed at room temperature, such as corrugated processing and assembly with tube material.

Its strength is approximately 14 to 18 kgf/-.

In addition, since it is exposed to high temperatures of 600℃ during brazing, the thinnest fin material may become deformed due to the restraint of the tube material and steel jig, which may cause core deformation and brazing defects. High temperature strength and sagging resistance are required.

Furthermore, excellent thermal conductivity is required to ensure heat exchange performance.

Currently, the AN-Mn-based 3003 alloy or an alloy in which Zn and In5Sn are added to this alloy are mainly used to meet these quality requirements.

[Problem to be solved by the invention]

However, recently automatic heat exchangers have become more compact and have improved performance (
There is a strong demand for improvements in heat dissipation characteristics.
For this reason, it is necessary to further reduce the thickness of the fin material and improve its thermal conductivity.

3003, which has been conventionally used for such situations.
In terms of strength, alloys can be made thinner, but when the walls are made thinner, heat dissipation decreases due to a decrease in the fin cross-sectional area.
It is necessary to improve thermal conductivity.

However, this 3003 series alloy has about 1.1 wt% of Mn added, and due to the solid solution of Mn in the alloy, the electrical conductivity, which indicates thermal conductivity, is about 38%lAC3, which is among the lowest among aluminum alloys. There is a problem in terms of thermal conductivity that hinders high performance.

[Means for Solving the Problems] The present invention has been developed as a result of intensive studies to solve such problems.
1.0wt%, Fe 0.3-1.5wt% and Mg
An aluminum fin material for an automobile heat exchanger, characterized in that the aluminum fin material contains 0.05 to 0.5 wt%, and the balance consists of AN and unavoidable impurities,
0.2-1.0wt%, Fe 0.3-1.5wt%,
Mg 0.05~0.5wt% and Zr 0.03~
An aluminum fin material for an automobile heat exchanger, characterized in that the aluminum fin material contains 0.3 wt% and the remainder consists of Al and unavoidable impurities.
．． 0wt%, Fe 0.3-1.5wt% and Mg0
．． 05 to 0.5 wt%, and further contains Zn 0.5 to 3
．． 0wt%, In0.01-0.1wt%, Sn 0.
An aluminum fin material for an automobile heat exchanger is characterized in that it contains one or more of 01 to 0.1 wt%, and the remainder consists of Al and unavoidable impurities; Si 0.2-1.0wt%, F
e 0.3-1.5wt%, Mg 0.05-0.5w
t% and Z r 0.03 to 0.3 wt%, and further contains Zn 0.5 to 3.0@t%, I n 0.01 to
0.1@t%, Sn 0.01 to 0.1wt%, or one or more of the following, with the balance consisting of AN and unavoidable impurities. be.

[Effect]

The reason for adding each additive element and the reason for limitation in the present invention are as follows.

Si is a solid solution in Alfi and a compound with Mg (MgzSi
) has the effect of improving material strength by precipitation, but the amount added is limited to 0.2 to 1.0 wt%.
If it is less than @t%, the effect will not be sufficient, and if it exceeds 1.0iit%, the melting point will rise, causing trouble in brazing, and the thermal conductivity will also decrease.

Fe has a low solid solubility in Alfi and has the effect of improving material strength without reducing thermal conductivity.
The addition amount was limited to 0.3 to 1.5 wt% because 0
．． This is because if it is less than 3 wt%, there is no effect, and if it exceeds 1.5 wt%, the effect not only becomes saturated but also the sagging resistance decreases.

Like Si, Mg has the effect of improving material strength by solid solution in A2 and precipitation of a compound with Si (Mg t Si'). The amount added is 0.05~0.5wt%
It is limited to 0.05 wt% because it is ineffective if it is less than 0.05 wt%.
This is because if it exceeds 5 wt%, the brazing properties will deteriorate, and when a fluoride-based flux is used, a MgF compound will be formed, which will significantly reduce the oxide film-destroying effect of the flux.

Zr is effective in improving material strength and sagging resistance.

It also has the effect of coarsening the grain size and preventing deformation at high temperatures. The addition amount was limited to 0.03 to 0.3 wt% because it is ineffective if it is less than 0.03 wt%.
%, plastic workability and thermal conductivity decrease. Furthermore, since Cr, Ti, SMn, and Zr have the same effect, one or more of them should be added at 0.03
~0.3 wt% may be added.

Zn, In, and Sn all have the effect of making the potential of the fin material less noble and increase the sacrificial anode action. The amount added is Z
n 0.5-3.0wt%, In 0.01-0.1
-t% and Sn 0.01 to 0.1 wt% because there is no effect below the lower limit, and the effect is saturated above the upper limit.

(Example〕 Next, the present invention will be explained in more detail with reference to Examples.

Twenty-six types of pair fins having the alloy components shown in Table 1 were experimentally manufactured by the following method.

After melting and casting in a mold according to the usual method, both sides were faced and 52
Perform homogenization treatment at 0°C for 3 hours, then further heat at 500°
C was hot rolled to a thickness of 5m, and then cold rolled to a thickness of 0.5m.
After the fin material had a thickness of 15 am, it was subjected to intermediate annealing for 380"CX 2 hr and finally cold rolled to obtain a fin material with a thickness of 0.1 M.

After the above fin material was brazed and heated in the atmosphere at 600"CX10w1n, its tensile strength and electrical conductivity were measured.

In addition, the brazing seam is made of 3003 core material, which is corrugated with a width of 16 mm, a fin height of 10 mm, and a pinch of 2.5 mm, and 4343 brazing filler metal is coated on both sides with a cladding rate of 10%.
(1,0 thickness) and in combination as shown in Figure 2, fluoride Franks (K/) I! , F4 and 3AlF.

A mixture of The joint status and the presence or absence of buckling of the fins were evaluated.

In addition, the brazed core is tested by CASS (JIS) for 200 hours.
H8681'), and the depth of pits generated in the brazing plate was measured by the depth of focus method. The results are shown in Table 2.

As is clear from Table 1' Mi 2 Hide Table 2, Examples N [11 to 16 of the present invention] exhibited a strength after brazing of 1 kgf/- or more, and 50% 1
It has an electrical conductivity of AC3 or higher, and its brazing properties and sacrificial anode action are similar to conventional material N[L26.

Comparison side stone with low Si, Fe SMg content 17.18.1
Comparative example No. 9 had insufficient strength, and comparative examples No. 20, 21, and 22, which contained large amounts of St 2 , Fe 2 , and Mg, had poor brazing properties. In the former two, the core was crushed due to melting of the fin, and in the latter, a large amount of flux residue was generated, making it impossible to braze.

Comparative example N1123.2 with a large amount of Zn, In, and Sn added
4.25 had a lot of corrosion on the fins, leaving problems with its long life.

〔Effect of the invention〕

As mentioned above, the fin material of the present invention has fin strength after brazing and sacrificial anode action comparable to conventional materials, and has significantly superior heat exchange performance than conventional materials, and has a remarkable industrial effect. be.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram of a heat exchanger for an automobile, and FIG. 2 is a combination diagram of a fin material and plating sheet used in an example. DESCRIPTION OF SYMBOLS 1... Fin 2... ERW pipe, 3... Header plate, 4... Resin tank, 5... Placing sheet.

Claims (1)

[Claims] 1) Si0.2-1.0wt%, Fe0.3-1.5w
t% and Mg0.05-0.5wt%, the balance A
1. An aluminum fin material for an automobile heat exchanger, characterized in that it comprises l and inevitable impurities. 2) Si0.2-1.0wt%, Fe0.3-1.5w
t%, Mg0.05-0.5wt% and Zr0.03
An aluminum fin material for an automobile heat exchanger, characterized in that the aluminum fin material contains ~0.3 wt%, and the remainder consists of Al and unavoidable impurities. 3) Si0.2-1.0wt%, Fe0.3-1.5w
t% and Mg0.05-0.5wt%, and further contains Zn0.5-3.0wt% and In0.01-0.1wt%.
%, one or two of Sn0.01-0.1wt%
An aluminum fin material for an automobile heat exchanger, characterized in that the aluminum fin material contains at least 10% of Al, and the remainder consists of Al and unavoidable impurities. 4) Si0.2-1.0wt%, Fe 0.3-1.5
wt%, Mg0.05-0.5wt% and Zr0.0
Contains 3-0.3wt%, and further contains Zn0.5-3.0w
t%, In0.01~0.1wt%, Sn0.01~0
．． Contains one or more of 1wt%, the remainder A
1. An aluminum fin material for an automobile heat exchanger, characterized in that it comprises l and inevitable impurities.