JPH0770684A - Fin material of al heat exchanger for brazing - Google Patents

Abstract

PURPOSE:To further reduce Ne thickness of the fins of an Al heat exchanger. CONSTITUTION:This fin material is made of an Al alloy contg. one or more among 0.01-0.3% Hf, 0.01-0.2% Mn, 0.01-0.2% Nb, 0.01-0.2% T8, 0.01-0.3% Ti, 0.01-0.2% V and 0.01-0.1% W as essential components or this fin material is obtd. by cladding with the Al alloy as a cladding material. When this fin material is used, the melting of fins during brazing is prevented, high strength is ensured and the thickness of the fins can further be reduced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an Al alloy fin material used as a fin material for an Al heat exchanger manufactured by a brazing method.

[0002]

2. Description of the Related Art Conventionally, in Al heat exchangers for automobiles, a brazing sheet is used for tubes and a thin sheet is used for fins, and the material used for the fins must be thin and have good strength. It is said that By the way, recently, there has been an increasing demand for weight reduction of vehicles, and there is an increasing tendency for fins to further reduce their wall thickness. For this reason, in recent fin materials, Mn is used in order to improve the strength so that the thickness can be further reduced.
Alternatively, an Al alloy added with elements such as Mg and Si is used.

[0003]

However, since brazing is usually carried out at a high temperature of about 600 ° C., thin fins are liable to be melted at the joint by contact with the molten brazing solder at this temperature, resulting in a sound brazing. May not be done.
In particular, when various additive elements are contained for thinning the fin, many of these elements have the effect of lowering the melting temperature of the fin material, so that the above-described phenomenon of melting of the joint is more remarkable. Will be seen in. Further, the action of lowering the melting temperature by these elements increases with an increase in the content.

As a result of detailed investigation of the mechanism of melting of fins into brazing during brazing, the present inventors have revealed the following facts. (1) When the fins come into contact with the molten brazing material, the fins are eroded from the fin surface even if the fin melting temperature is not reached (erosion), and the erosion reaches the inside of the fins with the passage of time. (2) When the fin is melted from the surface, the alloy components of the fin are also melted, but if elements such as Mn, Mg, and Si that lower the melting temperature of Al are contained in the braze, the liquid phase component of the braze increases and erosion occurs. Get more intense. (3) On the contrary, when the element for lowering the melting temperature of Al is contained in the molten brazing material, the liquid phase component of the brazing material is reduced, and the corrosion is suppressed.

Therefore, in order to suppress melting, pure Al containing no element for lowering the melting temperature is preferable, but the high temperature strength during brazing and the room temperature strength during use as a product are remarkably insufficient. Not only that, even with pure Al, the melting temperature cannot be said to be sufficiently high. Therefore,
The conventional material has a problem that it is difficult to sufficiently reduce the thickness due to the problem of melting of the joint portion. The present invention has been made in view of the above circumstances, and in the tendency of increasing the thickness of fins, which is becoming more and more widespread, it is possible to suppress the melting of the fins even under the conventional brazing conditions without adversely affecting the brazability. The purpose is to provide a fin material.

[0006]

[Means for Solving the Problem] Therefore, the inventors have decided to use pure Al.
As a result of various tests to find an alloy having a higher melting temperature than that of the above alloy and high strength at high temperature and room temperature, the following facts were found. 1) An alloy containing Hf, Nb, Ta, Ti, V, and W has a higher melting point than pure Al. 2) In these alloys, a compound of the contained element and Al is formed by adjusting the content, and finely and uniformly distributed, the strength at high temperature and room temperature remarkably increases. 3) The effect is further exhibited by adding these elements in combination. Moreover, there is no adverse effect on the brazing property.

The present invention has been made on the basis of the above-mentioned findings. Specifically, the Al heat exchanger fin material for brazing of the first invention is Hf: 0.01-0. 3%,
Mo: 0.01 to 0.2%, Nb: 0.01 to 0.2
%, Ta: 0.01 to 0.2%, Ti: 0.01 to 0.
3%, V: 0.01 to 0.2%, W: 0.01 to 0.1
%, One or two or more of them are contained, and the balance is made of Al and an Al alloy which is an unavoidable impurity.

A second invention is characterized by being composed of an Al alloy containing Zr: 0.01 to 0.2% by weight in addition to the composition of the first invention. A third invention is characterized in that, in addition to the composition in the first or second invention, it is made of an Al alloy further containing Mn: 0.3 to 1.5% by weight. A fourth aspect of the present invention is the composition according to any one of the first to third aspects, further comprising Z% by weight.
n: 0.1 to 2.0%, Sn: 0.02 to 0.15%,
In: An Al alloy containing one or more of 0.01 to 0.05% is characterized. A fifth invention is, in addition to the composition in any one of the first to fourth inventions,
Furthermore, in weight%, Mg: 0.05 to 0.7%, Si:
0.1-1.2%, Cr: 0.05-0.3%, Fe:
A containing one or more of 0.1 to 0.8%
1 alloy.

A sixth aspect of the present invention is, in% by weight, Mn: 0.3-
It is characterized in that the Al alloy according to any one of the first to fifth inventions is clad as a skin material on both surfaces of an Al alloy core material containing 1.5% and the balance consisting of Al and unavoidable impurities. And A seventh aspect of the present invention is that the Al alloy core material further comprises Si: in addition to the composition of the sixth aspect.
0.1-1.2%, Mg: 0.05-0.7%, Cr:
0.05-0.3%, Fe: 0.1-0.8%, V:
0.01-0.2%, Zr: 0.01-0.2%, T
i: One or two or more of 0.01 to 0.3% are contained, and the first to first layers are provided on both sides of the Al alloy core material.
The aluminum alloy according to any one of the inventions 5 to 5 is clad as a skin material.

An eighth aspect of the present invention is that the Al alloy core material has the composition of the sixth or seventh aspect, and further Z% by weight.
n: 0.1 to 2.0%, Sn: 0.02 to 0.15%,
In: One or more of 0.01 to 0.05% is contained, and the Al alloy according to any one of the first to fifth inventions is used as a skin material on both surfaces of the Al alloy core material. It is characterized by being clad.

[0011]

Function: That is, A using the Al alloy specified in the present application
According to the heat exchanger fin material, the melting temperature of the brazing material rises, so that melting of the joint portion during brazing is prevented. Further, both high temperature strength and room temperature strength are improved, and the fin can be made thinner. Further, according to the Al heat exchanger fin material in which the above Al alloy is clad to the Al alloy core material of the present invention, melting of the joint portion during brazing is prevented by the skin material, and the strength of the entire fin is Is sufficiently secured, and it becomes easier to reduce the thickness of the fin. It is not always necessary to use the same kind of alloy for the skin material that is clad on both sides of the core material, and alloys having different compositions may be clad on one surface of the core material.

The action of each component and the reason for limitation will be described below. [Al alloy for fin material or skin material] Hf: 0.01 to 0.3% Mo: 0.01 to 0.2% Nb: 0.01 to 0.2% Ta: 0.01 to 0.2% Ti: 0.01 to 0.3% V: 0.01 to 0.2% W: 0.01 to 0.1% These elements raise the melting point of the Al alloy and melt the joint during brazing. Prevent. Further, since a fine compound is generated to improve the strength, it is possible to make the fin material thinner. If the content of these elements is less than 0.01%, the desired effect is not sufficient. On the other hand, if the content of each element exceeds the upper limit, not only there is no further improvement effect, but also the dispersed particles of the compound become coarse and Since the hot rolling property, the cold rolling property and the workability of the fin are deteriorated and cracks are likely to occur, the respective values are within the above ranges. It should be noted that the above effects are further exhibited by the combined addition of these elements. However, in the case of multiple addition, it is desirable to regulate the total amount to 0.8% at maximum. The reason is that if the total amount exceeds 0.8%, the compound becomes coarse and the rolling processability is impaired.

Zr: 0.01 to 0.2% Zr is contained in order to particularly enhance the high temperature strength. However,
If it is less than 0.01%, the effect is not sufficient, and 0.2
If the content exceeds%, not only is there no further effect, but also the compound becomes coarse and the rolling processability is impaired. Mn: 0.3 to 1.5% Mn is optionally added to enhance strength. If the content is less than 0.3%, there is no sufficient strength-improving effect. On the other hand, if it exceeds 1.5%, the melting point of the Al alloy is lowered, causing melting of the joint during brazing. Specified in. For the same reason as above, it is desirable to exceed the lower limit by 0.5%.

Zn: 0.1 to 2.0% Sn: 0.02 to 0.15% In: 0.01 to 0.05% Zn, Sn, and In further add a sacrificial anode effect to the fin material. If desired, one kind or two or more kinds are added. If the amount is less than the above lower limit, the effect is not sufficient, and if the amount exceeds the upper limit, the workability of the material deteriorates.

Mg: 0.05 to 0.7% Si: 0.1 to 1.2% Cr: 0.05 to 0.3% Fe: 0.1 to 0.8% V: 0.01 to 0 .2% Zr: 0.01 to 0.2% Ti: 0.01 to 0.3% All of the above elements are included in order to increase the strength.
However, if the content is less than the lower limit, the effect is not sufficient and M
When g and Si exceed the upper limit value, the melting point is lowered, and it becomes easy to melt. On the other hand, when Cr, Fe, V, Zr, and Ti exceed the upper limit values, the compounds become coarse and the rolling workability of the material deteriorates.

[Al alloy for core material] Mn: 0.3 to 1.5% Mn is optionally added to enhance the strength. If the content is less than 0.3%, there is no sufficient strength-improving effect, while if it exceeds 1.5%, the melting point of the Al alloy is lowered, so the content is defined within the above range.

Mg: 0.05 to 0.7% Si: 0.1 to 1.2% Cr: 0.05 to 0.3% Fe: 0.1 to 0.8% V: 0.01 to 0 .2% Zr: 0.01 to 0.2% Ti: 0.01 to 0.3% All of the above elements are included in order to increase the strength.
However, if the content is less than the lower limit, the effect is not sufficient and M
When g and Si exceed the upper limit value, the melting point is lowered, and it becomes easy to melt. On the other hand, when Cr, Fe, V, Zr, and Ti exceed the upper limit values, the compounds become coarse and the rolling workability of the material deteriorates.

Zn: 0.1 to 2.0% Sn: 0.02 to 0.15% In: 0.01 to 0.05% Zn, Sn and In further impart a sacrificial anode effect, and therefore, if desired. 1 type (s) or 2 or more types are added. If the amount is less than the above lower limit, the effect is not sufficient, and if the amount exceeds the upper limit, the workability of the material deteriorates.

[0019]

【Example】

(Example 1) Inventive Al alloys 1 to 1 having the composition shown in Table 1
10 and Comparative Al alloys 1 to 7 were melted by a usual method, and the ingot was hot and cold rolled into a thin plate having a thickness of 0.06 mm.
In Comparative Al alloy 7, intermetallic compounds containing constituent elements were coarsely formed, and cracking occurred during hot rolling and cold rolling. Next, a tensile test sample was cut out from this thin plate, heat-treated at 600 ° C. for 5 minutes, and then subjected to a tensile test.

Further, the thin plate was corrugated and placed on a brazing sheet of 0.30 mm thickness using JIS3003 alloy as a core material and JIS4045 alloy as a brazing material (10% thickness). Was applied, and brazing was carried out at 600 ° C. for 5 minutes in an N ₂ gas atmosphere, and the degree of melting of the fin during brazing was observed. The results of the above tensile test and brazing test are shown in Table 2. As is clear from Table 2, in the Al alloy fin material of the present invention,
It has been found that even if the material is thin, not only does the material melt during brazing but also the strength is high, and it is useful as a thin fin material for brazing. On the other hand, it was revealed that the fin material as the comparative material was inferior in either strength or melting of the fin, and there was an obstacle to further thinning of the fin.

[0021]

[Table 1]

[0022]

[Table 2]

(Example 2) Al alloys 1 to 6 for core materials having the component compositions shown in Table 3 and Al alloys 1 to 5 for skin materials shown in Table 4 were melted by a usual method, and this ingot was cast. Was hot rolled. Next, 10% of the total thickness of the Al alloy for skin material was laminated on both surfaces of the hot-rolled plate made of Al alloy for core material, and clad by hot rolling to obtain a clad fin.
Further, for comparison, a comparative material in which the core material was used as the fin material was prepared, and the clad material and the comparative fin material were cold-rolled. The fin material had a thickness of 0.06 mm for both the invention material (cladding material) and the comparative material. This thin plate was heat-treated at 600 ° C. for 5 minutes and then subjected to a tensile test.

The thin plate was corrugated and placed on a brazing sheet similar to that used in Example 1.
A brazing test was conducted in the same manner as in. The results are shown in Table 5. As is clear from Table 5, since the Al alloy fin material of the present invention uses the high strength material as the core material, high tensile strength is obtained. Moreover, despite such a high-strength composition, the excellent brazing and erosion resistance of the skin material suppresses the erosion of the brazing material, resulting in excellent brazing properties. On the other hand, in the comparative material, the fin material having the high strength composition eroded the brazing material, and the fin was significantly melted.

[0025]

[Table 3]

[0026]

[Table 4]

[0027]

[Table 5]

[0028]

As described above, according to the Al heat exchanger fin material for brazing of the present invention, Hf: 0.
01-0.3%, Mo: 0.01-0.2%, Nb:
0.01-0.2%, Ta: 0.01-0.2%, T
i: 0.01 to 0.3%, V: 0.01 to 0.2%,
W: 0.01 to 0.1%, one or more of them are contained, and the balance is made of Al and an Al alloy which is an unavoidable impurity. Further, if desired, Zr: 0.01 to 0.2%. ,
Mn: 0.3-1.5%, Zn: 0.1-2.0%, S
n: 0.02 to 0.15%, In: 0.01 to 0.05
%, Mg: 0.05 to 0.7%, Si: 0.1 to 1.2
%, Cr: 0.05 to 0.3%, Fe: 0.1 to 0.8
%, One or two or more of them are contained, so that high strength is obtained and melting of the fins during brazing is prevented, so that the fins can be made even thinner and, by extension, the heat exchanger. There is an effect that contributes to the weight reduction of.

In another embodiment of the present invention, Mn:
0.3 to 1.5%, the balance consisting of Al and unavoidable impurities, and, if desired, Si: 0.1 to 1.2.
%, Mg: 0.05 to 0.7%, Cr: 0.05 to 0.
3%, Fe: 0.1 to 0.8%, V: 0.01 to 0.2
%, Zr: 0.01 to 0.2%, Ti: 0.01 to 0.
3%, Zn: 0.1 to 2.0%, Sn: 0.02 to 0.
15%, In: 0.01 to 0.05%, one or two
Since the above Al alloys are clad on both sides of the Al alloy core material containing at least one kind as a skin material, sufficiently high strength is surely ensured by the core material, and the melting of the fins during brazing does not occur. There is an effect that is blocked by the material.

Claims (8)

[Claims] 1. Hf: 0.01 to 0.3% by weight,
Mo: 0.01 to 0.2%, Nb: 0.01 to 0.2
%, Ta: 0.01 to 0.2%, Ti: 0.01 to 0.
3%, V: 0.01 to 0.2%, W: 0.01 to 0.1
% Of 1% or more, and the balance is made of Al and an Al alloy that is an unavoidable impurity. 2. An Al heat exchanger fin material for brazing, which is made of an Al alloy containing Zr: 0.01 to 0.2% in weight% in addition to the composition of claim 1. 3. An Al heat exchanger fin for brazing, characterized in that, in addition to the composition according to claim 1 or 2, it further comprises an Al alloy containing Mn: 0.3 to 1.5% by weight. Material 4. In addition to the composition according to any one of claims 1 to 3, further, in% by weight, Zn: 0.1 to 2.0%, S
n: 0.02 to 0.15%, In: 0.01 to 0.05
% Al heat exchanger fin material for brazing, which is made of an Al alloy containing one or more of 5. In addition to the composition according to any one of claims 1 to 4, further, by weight%, Mg: 0.05 to 0.7%, S
i: 0.1 to 1.2%, Cr: 0.05 to 0.3%, F
e: Al heat exchanger fin material for brazing, characterized by comprising an Al alloy containing one or more of 0.1 to 0.8% 6. The aluminum alloy core material containing Mn in an amount of 0.3 to 1.5% by weight with the balance being Al and inevitable impurities, on both sides, respectively. Of A
Al heat exchanger fin material for brazing, characterized in that a 1-alloy is clad as a skin material 7. An Al alloy core material, in addition to the composition according to claim 6, further comprising Si: 0.1 to 1.2% and M by weight%.
g: 0.05 to 0.7%, Cr: 0.05 to 0.3%,
Fe: 0.1 to 0.8%, V: 0.01 to 0.2%, Z
One or two or more of r: 0.01 to 0.2% and Ti: 0.01 to 0.3% are contained, and both surfaces of this Al alloy core material are contained in each of claims 1 to 5. Al heat exchanger fin material for brazing, characterized in that the Al alloy according to any one of claims 1 to 3 is clad as a skin material. 8. An Al alloy core material, in addition to the composition according to claim 6 or 7, further comprising Zn: 0.1 to 2.0 in weight%.
%, Sn: 0.02 to 0.15%, In: 0.01 to
One or more of 0.05% is contained, and the Al alloy according to any one of claims 1 to 5 is clad as a skin material on both surfaces of the Al alloy core material. Al heat exchanger fin material for brazing