JP3133390B2 - High strength aluminum alloy clad material for low temperature brazing - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high-strength aluminum alloy clad material for low-temperature brazing for brazing at a temperature of 500 DEG C. or less, and is particularly used as a heat exchanger member for automobiles and the like.

[0002]

2. Description of the Related Art Most heat exchangers for automobiles are made of Al or A.
1 alloy is used and manufactured by a brazing method. Normally, an Al-Si brazing material is used for brazing, and therefore, brazing is performed at a high temperature of about 600 ° C.
In the brazing using an Al-Si brazing material, the brazing material may be supplied as a single powder, a wire, or a plate, but generally, the brazing material is hot-pressed to the core material in consideration of workability. In many cases, it is carried out with a so-called brazing sheet clad by the above. For example, JISA3003 (Al-0.15wt% Cu-1.1wt%
Mn) as the core material, one side of which is JISA7072 (Al-1wt%
Zn) sacrificial material and clad on the other side with JISA4343
(Al-7.5wt% Si) Bed les chromatography Managing sheets of brazing material covering is being used.

[0003]

In recent years, due to environmental issues, there has been a demand for a reduction in vehicle weight due to a demand for improved fuel efficiency of automobiles, and a change in refrigerant due to the ban on the use of specific CFCs has led to a tendency for heat exchangers to become larger. There is an urgent need to reduce the weight and weight of the heat exchanger by reducing the thickness of the exchanger member. However, in the case of a heat exchanger member formed by brazing using a conventional Al-Si brazing material, only a material having a high melting point can be used because it is exposed to a high temperature of about 600 ° C, and there is a limit to increasing the strength of the member. there were. Further, the low-temperature brazing member has a problem that the weight of the member increases because a brazing material having a large specific gravity, such as Zn or Sn, is used as the brazing material. Furthermore, the shape of the heat exchanger tends to be more complicated due to the miniaturization of the heat exchanger. However, as described above, when a high-strength material is used to reduce the weight of the member, the formability of the material is reduced. However, there is a problem that it is difficult to obtain a predetermined shape.

[0004]

According to the present invention, as a result of various studies, a high-strength, high-formability, high-strength aluminum alloy clad material for low-temperature brazing coated with a low-melting brazing material has been developed. is there.

That is, one of the clad materials of the present invention is MgO.
1 to 1.4 wt% (hereinafter, wt% is abbreviated as%) Si 1.3 to 3.5%, Cr 0.01 to 0.35%, Mn 0.01 to 1.80%, Zr0.
01-0.35%, Hf0.03-0.50%, V0.03-0.35%, Ni
0.03 to 3.50%, Fe 0.02 to 1.50%, Ti 0.005 to 0.35%
Contains at least one of them in the range of, and at least one side of the aluminum alloy material consisting of the balance Al, 500
It is characterized by being coated with a brazing material that melts at a temperature of not more than ℃.

Another one of the clad materials of the present invention is Mg
0.1 to 1.4%, containing Si 1.3 to 3.5% further Cr0.01~
0.35%, Mn 0.01-1.80%, Zr 0.01-0.35%, Hf0.
03-0.50%, V0.03-0.35%, Ni0.03-3.50%, Fe
The sacrificial material is clad on one side of an aluminum alloy material containing one or more kinds within a range of 0.02 to 1.50% and Ti 0.005 to 0.35%, with the balance being Al. It is characterized in that the opposite surface is coated with a brazing material that melts at 500 ° C. or lower.

Another one of the clad materials of the present invention is Mg
0.1 to 1.4%, Si 1.3 to 3.5%, Cu 0.05 to 0.4%, Cr 0.01 to 0.35%, Mn 0.01 to 1.80%, Zr 0.
01-0.35%, Hf0.03-0.50%, V0.03-0.35%, Ni
0.03 to 3.50%, Fe 0.02 to 1.50%, Ti 0.005 to 0.35%
At least one surface of an aluminum alloy material comprising the balance of Al
It is characterized in that it is coated with a brazing material that melts in the following.

Further, another one of the clad materials of the present invention is made of Mg.
0.1 to 1.4%, Si 1.3 to 3.5%, Cu 0.05 to 0.4%, Cr 0.01 to 0.35%, Mn 0.01 to 1.80%, Zr 0.
01-0.35%, Hf0.03-0.50%, V0.03-0.35%, Ni
0.03 to 3.50%, Fe 0.02 to 1.50%, Ti 0.005 to 0.35%
One or two or more of them are contained within the range, and the sacrifice material is clad on one side of an aluminum alloy material consisting of the balance Al, and the surface opposite to the surface on which the sacrifice material is clad is melted at 500 ° C or less. It is characterized by being coated with a brazing filler metal.

[0009]

In the present invention, the alloy composition is specified as described above for the following reasons. Mg and Si contribute to the improvement of strength without forming fine deposits and impairing the formability. However, when the amount is less than the lower limit, the contribution to the strength cannot be expected much, and when the amount exceeds the upper limit, the corrosion resistance is significantly deteriorated.

[0010] Although Cu has the effect of increasing the strength of the material, its effect is not sufficient if its content is less than the lower limit, and if it is added above the upper limit, the moldability is significantly reduced. Thus, although Cu is effective in improving the strength, when Cu is added, the moldability tends to slightly decrease, and therefore, Cu is added in consideration of the strength and moldability required for the product, or is not added. Should be determined.

[0011] Cr, Mn, Zr, Hf, V, Ni, Fe
Both Ti and Ti improve the strength of the material, especially high-temperature strength, and prevent deformation during and after brazing. Therefore, in general, one or more of these elements are added in a predetermined amount. On the other hand, however, the addition of these elements may lead to the refinement of the material structure of the material, the diffusion of the brazing material to increase the grain boundary area, and the risk of deteriorating the corrosion resistance. In doing so, it is necessary to determine the amount of the product based on the site of use. However, the above-mentioned effects cannot be expected with the addition amounts below the lower limit, respectively, and when added above the upper limit, a coarse compound is generated in the material, and the moldability, strength, toughness, and corrosion resistance of the material are deteriorated. . Regarding impurity elements other than the above elements, if the content is 0.05% or less, there is no adverse effect on the characteristics of the material. 0.05% for B, Be, etc. for improving castability, or for misch metal, etc. for improving formability.
It can be added in the following range.

As the brazing material having a melting point of 500 ° C. or less in the present invention, for example, pure Zn, Zn-0 to 28% Al, Zn-
Any alloys such as Al-based, Zn-Cd-based, Sn-Zn-based, and Sn-Pb-based can be used as long as the melting point is 500 ° C or less. However, considering the corrosion resistance of the product after brazing, Zn
Alloy-based brazing materials have the widest applicability. The brazing material may be coated by any method such as a hot pressing method, a thermal spraying method, a hot-dip plating method, an electroplating method, and a vapor deposition method. However, in consideration of industrial economics (coating cost and productivity), it is preferable to coat by hot pressing or plating. The coating thickness of the brazing material is not particularly limited, and may be determined according to the product shape and the use site.

At present, a radiator, for example, as shown in FIG. 1, a fin (2) is mounted between a number of liquid flow pipes (1), and a tank is mounted by providing headers (3) at both ends of the liquid flow pipe (1). When a part of the member is exposed to a corrosive environment, such as a brazing sheet used as a liquid pipe for a radiator, the inner surface of the pipe exposed to the corrosive environment includes:
Generally, a material having a low potential such as a JISA7072 alloy is clad as a sacrificial material. Therefore, also in the present invention, one side of the core material (the opposite side of the brazing plate) is
It is possible to use a base alloy of 50 mV or more as a sacrificial material. Normal sacrificial materials include JISA7072 alloy, Al-Sn
System, Al-Ca system and the like are used, but in the clad material of the present invention, the corrosion resistance is better than those of the sacrificial layer alloy JISA1100.
Pure Al-based materials can also be used as a sacrificial material, and when these alloys are clad on the surface of the material, the corrosion resistance of the product becomes very favorable.

The clad material of the present invention may be further clad with another alloy layer between the core material and the brazing material or between the core material and the sacrificial material for the purpose of improving corrosion resistance. If the alloy layer is further clad between the core material and the sacrificial material, the potential of the sacrificial material must be lower than the potential of the alloy layer by 50 mV or more, and the alloy layer is more than the core material. It is preferably 50 mV or more.

[0015]

The present invention will be described below with reference to examples. (Example 1) Alloys having the compositions shown in Table 1 were cast by DC casting to a thickness of 400 mm and a width of 400 mm.
2,300 ingots were homogenized (400 ℃ × 12h + 52
After 0 ° C. × 12 h), a hot-rolled and cold-rolled sheet material having a thickness of 1 mm was obtained. As shown in FIG. 2, the plate (4) is passed through a brazing plating bath (6) by a guide roller (5), and a Zn-5% Al alloy is coated on one side of the plate (4) to a thickness of 30 μm. Plated.

A tensile test piece and an Erichsen test piece were processed from this plate material, and the formability of the plate material was evaluated by an elongation value by a tensile test and an overhang property by an Erichsen test. In the Erichsen test, a ball-head punch having a diameter of 33 mm was overhanged, and the overhangability was evaluated based on the maximum height at which cracks did not occur. In addition, as a simulated brazing heating, insert these sheets into a furnace in a nitrogen gas atmosphere with a dew point of -40 ° C maintained at a temperature of 450 ° C and perform brazing heating. After heating, remove them from the furnace and air-cool them. The tensile test was performed by processing a tensile test piece from the plate material of Example 1.
These results are also shown in Table 1.

[0017]

[Table 1]

As is evident from Table 1, the clad material of the present invention has better formability before heating and higher strength after heating than the comparative material or the conventional material outside the scope of the present invention.

(Example 2) With the constitution shown in Table 2, a 1.2 mm thick plate material in which a sacrificial material was clad on one surface of a core material at a ratio of 10% was produced by a normal hot pressing method. Using this plate material, a Zn-11% Al alloy (melting point: 425 ° C.) by the hot-dip plating method shown in FIG.
A brazing material was plated on the side opposite to the sacrificial material to a thickness of 80 μm .

[0020] It like the AlF ₃ and C _S F degreasing was coated with 10% strength solution of fluoride-based flux was a basic composition of, in a furnace in a nitrogen gas atmosphere having a dew point of -40 ℃ maintained at a temperature 450 ° C. Inserting and brazing were performed. A tensile test piece and an Erichsen test piece were processed from the material before heating, and the moldability was evaluated in the same manner as in Example 1. In addition, a tensile test specimen was processed from the heated material, and mechanical properties were evaluated by a tensile test. The 720
The time was evaluated by CASS test. Evaluation was made based on the maximum pit depth after the corrosion test.

[0021]

[Table 2]

As is evident from Table 2, the clad material of the present invention is not only excellent in formability and strength, but also exhibits the same properties as the conventional material in which the sacrificial material is clad in corrosion resistance.

[0023]

As described above, according to the present invention, it is possible to supply a brazing member for a heat exchanger having a higher strength and a higher moldability than conventional ones.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an example of a radiator with a part cut away.

FIG. 2 is an explanatory view showing a hot-dip plating method.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Flow-through pipe 2 Fin 3 Header 4 Plate material 5 Guide roller 6 Brazing bath

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-1-107961 (JP, A) JP-A-62-173095 (JP, A) JP-A-3-122238 (JP, A) 134128 (JP, A) JP-A-58-164748 (JP, A) JP-A-4-247841 (JP, A) JP-A-4-358038 (JP, A) JP-A-4-247840 (JP, A) JP-A-4-263035 (JP, A) JP-A-4-263036 (JP, A) JP-A-5-368 (JP, A) JP-A-4-346635 (JP, A) JP-B-58-46540 (JP, B2) (58) Field surveyed (Int. Cl. ⁷ , DB name) C22C 21/00-21/18 B23K 35 / 22,35 / 28

Claims (4)

(57) [Claims] 1. An alloy containing 0.1 to 1.4 wt% of Mg and 1.3 to 3.5 wt% of Si, further containing 0.01 to 0.35 wt% of Cr, 0.01 to 1.80 wt% of Mn,
r0.01 ~ 0.35wt%, Hf0.03 ~ 0.50wt%, V0.03 ~ 0.35wt
%, Ni 0.03 to 3.50 wt%, Fe 0.02 to 1.50 wt%, Ti 0.005
Contains any one or two or more within the range of ~ 0.35 wt%,
A high-strength aluminum alloy clad material for low-temperature brazing, characterized in that at least one surface of an aluminum alloy material consisting of the remaining Al is coated with a brazing material that melts at 500 ° C. or less. 2. The composition contains 0.1 to 1.4 wt% of Mg and 1.3 to 3.5 wt% of Si, and further contains 0.01 to 0.35 wt% of Cr, 0.01 to 1.80 wt% of Mn,
r0.01 ~ 0.35wt%, Hf0.03 ~ 0.50wt%, V0.03 ~ 0.35wt
%, Ni 0.03 to 3.50 wt%, Fe 0.02 to 1.50 wt%, Ti 0.005
Contains any one or two or more within the range of ~ 0.35 wt%,
A sacrificial material is clad on one side of an aluminum alloy material consisting of the remaining Al, and on the surface opposite to the surface on which the sacrificial material is clad,
A high-strength aluminum alloy clad material for low-temperature brazing, which is coated with a brazing material that melts at 500 ° C or lower. 3. Mg 0.1 to 1.4 wt%, Si 1.3 to 3.5 wt%, C
u 0.05-0.4wt%, Cr 0.01-0.35wt%, M
n0.01-1.80wt%, Zr0.01-0.35wt%, Hf0.03-0.50
wt%, V0.03-0.35wt%, Ni0.03-3.50wt%, Fe0.02
~ 1.50wt%, Ti0.005 ~ 0.35wt% in the range of any one or more, containing at least one side of the aluminum alloy material consisting of the remainder Al is coated with a brazing material melting at 500 ℃ or less High-strength aluminum alloy clad material for low-temperature brazing, characterized in that: 4. Mg 0.1 to 1.4 wt%, Si 1.3 to 3.5 wt%, C
u 0.05-0.4wt%, Cr 0.01-0.35wt%, M
n0.01-1.80wt%, Zr0.01-0.35wt%, Hf0.03-0.50
wt%, V0.03-0.35wt%, Ni0.03-3.50wt%, Fe0.02
~ 1.50 wt%, containing any one or two or more in the range of 0.005 ~ 0.35 wt% Ti, clad the sacrificial material on at least one side of the aluminum alloy material consisting of the balance Al, clad the sacrificial material A high-strength aluminum alloy clad material for low-temperature brazing, characterized in that a surface opposite to the surface is coated with a brazing material that melts at 500 ° C or less.