JP2000141076A - Aluminum alloy clad material for heat exchanger excellent in corrosion resistance and strength - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an aluminum alloy clad material for heat exchanger excellent in corrosion resistance, brazablity and high strength property after brazing as well as in forming workability before brazing. SOLUTION: In an aluminum alloy clad material composed of cladding of brazing material on one-side surface or both-side surfaces of a core material, the core material is composed of an Al alloy containing >0.6 and <=1.2% Cu, <0.25% Si, <=0.3% Fe, 0.06-0.35% Ti, and the balance Al with inevitable impurities, and the brazing cladding on one-side surface or both-side surfaces of the core material is composed of Al-Si aluminum alloy; thereby reducing the thickness of working fluid passage material becomes available and getting a lighter weight and a longer life of heat exchanger such as radiator and condenser is achieved.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an aluminum alloy clad material for a heat exchanger having excellent corrosion resistance and strength, and more particularly to a material for a working fluid passage of a heat exchanger joined by brazing, such as an evaporator or a radiator of a car air conditioner. The present invention relates to an aluminum alloy clad material for a heat exchanger which is particularly excellent in corrosion resistance, has excellent moldability before brazing, and has high strength after brazing.

[0002]

2. Description of the Related Art Aluminum alloy heat exchangers are widely used as radiators, oil coolers, intercoolers, evaporators and condensers for heaters and air conditioners of automobiles, and heat exchangers for oil coolers of hydraulic equipment and industrial machines. . There are various types of aluminum alloy heat exchangers, but from the viewpoint of weight reduction, a working fluid passage is formed by superimposing aluminum alloy clad materials and forming a working fluid passage between them. Attention has been paid to a laminated heat exchanger (Drone cup type heat exchanger) manufactured by combining corrugated aluminum alloy fins and integrating them by brazing.

For example, a drone cup type evaporator 1
As shown in FIGS. 1 and 2, core plates 2 and 3 made of press-formed aluminum alloy clad material and aluminum alloy fins 4 (hereinafter simply referred to as fins) processed by corrugation are laminated and brazed. Melting the brazing material of the core plates 2 and 3
And 3 and the fin 4 are joined to form a working fluid passage 5 such as a refrigerant between the core plates 2 and 3.

The core plates 2 and 3 are made of Al-Mn, Al-Mn-Cu, Al-Mn-M
g-based, Al-Mn-Cu-Mg-based aluminum alloys containing Mn, such as JIS A3003 alloy and 3005 alloy, are used as brazing filler metals.
l-Si-Mg system, Al-Si-Mg-Bi system, Al-
Si-Mg-Be system, Al-Si-Bi system, Al-Si
-Be-based, Al-Si-based alloys such as Al-Si-Bi-Be-based and the like are used, and an aluminum alloy clad material obtained by cladding the brazing material on one or both surfaces of the core material is used. I have.

As the fin 4, an aluminum alloy obtained by adding Cu, Mg, Zn, Sn, In or the like to an Al-Mn alloy is used. As a method of brazing the fin 4 and the core plates 2 and 3, In general, vacuum brazing is applied, but a flux brazing method using a chloride-based flux or a fluoride-based flux is also applied.

In recent years, weight reduction and cost reduction of heat exchangers have been strongly demanded, and in order to achieve these demands, it is necessary to further reduce the thickness of the heat exchanger constituent materials such as working fluid passages. For example, if the strength is increased in order to reduce the thickness of the aluminum alloy clad material constituting the working fluid passage, the elongation is reduced, the formability is reduced, and the corrosion resistance is also deteriorated. Because of the problem of durability, there is a demand for the development of a clad material having further improved elongation (formability), strength after brazing, and corrosion resistance.

The aluminum alloy clad material conventionally used as the core plates 2 and 3 of the drone cup type evaporator 1 has a core material of an aluminum alloy containing Mn as described above, and has a pitting corrosion resistance. It is not enough. For example, when applied to a working fluid passage material of a refrigerant, it has been experienced that a penetration leakage accident often occurs due to pitting.

In order to improve the pitting resistance of the working fluid passage material, the fin 4 is made of a material having a potential lower than that of the working fluid passage material, for example, Al-Mn-Zn, Al-Mn.
It is conceivable to use a Sn-based or Al-Mn-In-based alloy or the like to protect the working fluid passage material by utilizing the sacrificial anode effect of the fins 4 made of these materials. Has an effect only on the working fluid passage material in the vicinity of the joint with the fin 4, and the sacrifice anode effect of the fin 14 does not reach with the working fluid passage material at a position away from the fin 4, and pitting is inevitable. .

Further, since the aluminum alloy clad material has an aluminum alloy containing Mn as a core material, it is inevitable that a fine Mn-based compound is generated in the core material. When the degree of the previous press working is low, the recrystallization of the core material during brazing is suppressed by the fine Mn-based compound in the core material, and the brazing material diffuses into the core material, and the brazing property is reduced. Insufficiency may occur.

In order to improve the corrosion resistance of an aluminum alloy clad material for a working fluid passage, a clad material in which Cu, Ti, Cr or Zr is added to its core material (Japanese Patent Publication No. 6-41621, Japanese Patent Application Laid-Open No. 63-41663) JP-A-241133, JP-A-64-83396, JP-A-2-258
945), and the content of Fe, which constitutes the cathode compound among the core components and deteriorates the corrosion resistance, is set to 0.
Cladding material limited to 2% or less (JP-A-64-8339)
No. 6) or a clad material in which the contents of Fe and Si in the core material are each limited to improve intergranular corrosion resistance (Japanese Patent Publication No. 6-41621, Japanese Patent Application Laid-Open No.
Although the aluminum alloy clad material proposed above has an improvement in corrosion resistance, the purpose of the improvement in the formability and the strength characteristics after brazing is sufficient. Cannot be achieved.

In order to improve the brazing property, the temperature of the core material is homogenized within a range of 580 ° C. to 620 ° C.
There has been proposed a method of controlling a fine Mn-based compound of 1 μm or less to 35% or less (see Japanese Patent Application Laid-Open No. 2-258945). Although some improvement effect can be obtained, an Al—Mn-based alloy is used as a core material. In this case, the precipitation of fine Mn-based compounds cannot be avoided, and there is a limit to the improvement.

[0012]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned conventional problems particularly in the working fluid passage material and to obtain an aluminum alloy clad material which satisfies the demand for thinning the working fluid passage material. Experiments and examinations were conducted on various aspects of the composition of the core material, the composition of the brazing material clad on both sides, and the effects of these combinations on the formability, formability, brazing properties, strength characteristics after brazing and corrosion resistance. The purpose of the present invention is to provide an aluminum alloy for a heat exchanger having particularly good corrosion resistance, excellent moldability before brazing, easy brazing, and improved strength characteristics after brazing. An object of the present invention is to provide a clad material.

[0013]

In order to achieve the above-mentioned object, an aluminum alloy clad material for a heat exchanger according to the present invention, which has excellent corrosion resistance and strength, comprises an aluminum alloy clad material in which a brazing material is clad on one or both surfaces of a core material. A core material comprising: Cu: more than 0.6% and 1.2% or less;
0.2% or less, Fe: 0.3% or less, Ti: 0.06% to 0.35%, the balance is made of an aluminum alloy containing Al and impurities, and the brazing material is made of an Al-Si-based aluminum alloy Is a first feature.

In the above clad material, the brazing material contains Cu: 0.06% to 1.0%, and the Cu content of the brazing material (γ ₂ %) is calculated from the Cu content of the core material (γ ₁ %). The second characteristic is that the value obtained by subtracting the above is 0.2% or less (γ ₁ −γ ₂ ≧ 0.2%).
0%, In: 0.005% to 0.1% and Sn: 0.01% to 0.1%
Of at least one or more Al-Si
A third feature is that it is made of a series aluminum alloy.

[0015] The aluminum alloy clad material for a heat exchanger of the present invention, which is excellent in corrosion resistance and strength, is further an aluminum alloy clad material in which a brazing material is clad on one or both sides of a core material, wherein the core material is Cu: Over 0.6% 1.2
% Or less, Si: 0.2% or less, Fe: 0.3% or less, Ti: 0.06
% To 0.35%, Mg: 0.06% to 0.5%, with the balance being Al
A fourth feature is that the brazing material is made of an Al-Si-based aluminum alloy.

In the above clad material, the brazing material is C
u: 0.06% to 1.0%, and the value obtained by subtracting the Cu content (γ ₂ %) of the brazing material from the Cu content (γ ₁ %) of the core material is 0.2% or more (γ ₁ −γ ₂ ≧ 0.2%), and the brazing material further contains Zn: 0.3% to 4.0%,
n: 0.005% to 0.1% and Sn: 0.01% to 0.1%
Fifth and sixth features of the present invention are constituted by an Al-Si-based aluminum alloy containing at least one or more kinds.

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION The significance of the alloy components in the high-strength aluminum alloy clad material for heat exchangers (hereinafter simply referred to as aluminum alloy clad material) having excellent corrosion resistance according to the present invention and the reasons for limiting the same will be described. (1) Components of core material Cu in the core material enhances the strength of the core material, makes the potential of the core material noble, and increases the potential difference with the brazing material layer acting as a sacrificial anode layer, thereby preventing corrosion. Function to enhance. Further, Cu in the core material diffuses into the brazing material at the time of heating by brazing to form a continuous concentration gradient. as a result,
The potential on the core material side is noble, the potential on the surface side of the brazing material is low, a continuous potential gradient is formed in the brazing material, the corrosion form is a horizontal spread general corrosion type, corrosion from the outside Imparts anticorrosive action to A preferred content range of Cu is:
When the content exceeds 0.6%, the effect is small, and when the content exceeds 1.2%, the elongation is small and the formability is insufficient, and the core material may be melted during brazing. In addition, the corrosion resistance of the core material itself deteriorates. A more preferred content range of Cu is more than 0.8% and 1.2%.
% Or less.

Both Si and Fe in the core material constitute a compound serving as a cathode and reduce the corrosion resistance. Therefore, Si should be restricted to 0.2% or less and Fe to 0.3% or less. However, since high-purity aluminum ingots with low contents of Si and Fe are costly, the content of Si is 0.01% or more and 0.1% or more in terms of corrosion resistance and cost.
And the content of Fe is preferably in the range of 0.01% to 0.1% and 0.3% or less.

The Ti in the core has the effect of further improving the corrosion resistance of the core. That is, Ti in the core material is divided into a high-concentration region and a low-concentration region and solidifies. When they are rolled, they are distributed alternately in a layered manner in the thickness direction, and T
Since the region having a low i concentration corrodes preferentially as compared with the region having a high Ti concentration, the corroded form is layered to prevent the progress of corrosion of the core material in the thickness direction, thereby improving pitting corrosion resistance.
The preferable content range of Ti is 0.06% to 0.35%, and 0.06% to 0.35%.
%, The effect is not sufficient. If it exceeds 0.35%, a coarse compound is formed during casting of aluminum alloy clad material,
Rolling workability is impaired. The more preferable content range of Ti is 0.1% to 0.35%.

Mg in the core material has an effect of forming Mg ₂ Si together with Si and improving the strength of the core material. The preferred range of Mg content is 0.06% to 0.5%. If the content is less than 0.06%, the effect is small. If the content is more than 0.5%, the elongation is reduced and the formability is insufficient. Melting may occur, and in addition, the corrosion resistance of the core material itself deteriorates. Furthermore, in the case of brazing using a fluoride-based flux, since the fluorine (F) of the flux component reacts with Mg in the alloy to generate a compound such as MgF ₂ , the absolute amount of the flux will be insufficient. It is easy to cause poor mounting.

In addition, Zn and M contained as impurities
n, Cr, Zr, etc. may be contained in the core material within a range that does not impair the effects of the present invention. However, since Zn makes the potential of the core material low and reduces the potential difference from the fin material used as the sacrificial anode layer and impairs the corrosion resistance, it must be 0.2% or less.
Further, Mn, Cr, and Zr are each desirably less than 0.05% because recrystallization of the core material is suppressed, the brazing material is easily diffused into the core material, and the brazing property is reduced.

(2) Components of brazing filler metal The brazing filler metal differs depending on the brazing method, but an Al alloy containing Si is usually used. When vacuum brazing is applied, an Al-Si-Mg alloy brazing material (JIS400
4, 4005, 4N04, etc.), Al-Si-Mg-B
An i-type alloy brazing material (JIS 4104 or the like) or the like is used. When applying the fluoride flux brazing, an Al-Si alloy brazing material (JIS 4343, 40
45, 4047).

Cu in the brazing material has an effect of increasing the strength of the aluminum alloy clad material by being added to the brazing material. The preferred content range of Cu is 0.06% to 1.0%. If the content is less than 0.06%, the effect is small. If the content exceeds 1.0%, elongation is reduced and rolling becomes difficult, and production of an aluminum alloy clad material becomes difficult. The more preferable content range of Cu is more than 0.3% and 1.0% or less.

The Cu content in the core material is determined by the C content in the brazing material.
When the content is higher than the u content, the potential of the core material is more noble than that of the brazing material, so the brazing material layer on the surface of the aluminum alloy cladding material exhibits a sacrificial anode effect on the core material, and the corrosion resistance of the aluminum alloy cladding material Improve. The greater the difference between the Cu content in the core material and the Cu content in the brazing material, the greater the potential difference and the better the corrosion resistance of the aluminum alloy clad material. Core material C
From the u content (γ ₁ %) to the Cu content of the brazing material (γ ₂ %)
By setting the value obtained by subtracting the above value to 0.2% or more (γ ₁ −γ ₂ ≧ 0.2%), sufficient corrosion resistance can be achieved.

By adding Zn in the brazing material to the brazing material, it lowers the potential of the brazing material, gives a sacrificial anode effect to the brazing material with respect to the core material, and improves the corrosion resistance of the aluminum alloy clad material. . The preferred range of Zn is 0.3% to 4.
0%, the effect is small at less than 0.3%, 4.0%
If the content exceeds the above range, the brazing portion of the aluminum alloy clad material is significantly corroded and consumed, the sacrificial anode effect of the brazing portion is not maintained for a long time, and the self-corrosion resistance of the brazed joint is deteriorated.

By adding In and Sn in the brazing material, the potential of the brazing material is made low by adding the brazing material, a sacrificial anode effect is given to the brazing material with respect to the core material, and the corrosion resistance of the aluminum alloy clad material is improved. Improve. The preferred content ranges of In and Sn are 0.005% to 0.1% and 0.01% to 0.1%. The effect is small when the content is less than the lower limit, and when the content exceeds the respective upper limit, the content of the aluminum alloy clad material is reduced. Corrosion wear of the brazing material is remarkable, so that the sacrificial anode effect of the brazing material is not maintained for a long period of time, and in addition, the self-corrosion resistance of the brazing joint deteriorates.

In addition, as another element in the brazing material, for example, 0.1% or less of Be, S
One, two or more of r, Li and Na may be contained. In addition, elements such as Mn, Ti, Cr, Zr, and Ni can be contained in a small amount in the brazing material within a range that does not impair the effects of the present invention, for the purpose of improving the strength of the brazing material. However, if the content of these elements increases, the self-corrosion resistance of the brazing filler metal decreases, so the total content of these elements is preferably suppressed to 1% or less.

The aluminum alloy clad material for a heat exchanger according to the present invention, which is excellent in corrosion resistance and strength, is obtained by subjecting an aluminum alloy constituting a core material and a brazing material to, for example, ingot by continuous casting, homogenizing treatment, or homogenizing. After the treatment, hot-rolled to a predetermined thickness, then combine the materials, according to a conventional method, hot-rolled into a clad material, finally cold-rolled to a predetermined thickness, and finally annealing It is manufactured through a process.

In order to use the aluminum alloy clad material of the present invention as a constituent member of, for example, a drone cup type evaporator, as shown in FIGS. Then, these are laminated, and a fin 4 made of aluminum alloy is brazed to the outside of the core plates 2 and 3 to assemble the drone cup type evaporator 1. To form a tank material such as a radiator or a capacitor, an aluminum alloy clad material is press-formed into a tank shape and brazed. It is preferable to apply an inert gas atmosphere brazing using a fluoride-based flux or a vacuum brazing to both brazing joints.

[0030]

Example 1 An aluminum alloy for a core material having a composition shown in Table 1 (compositions shown in core materials Nos. 1 to 6) by continuous casting, and Table 2
(Braze No. A, B, C, D, E, F, G
The aluminum alloy for the brazing material having the composition shown in the following) is ingoted, and the aluminum alloy for the core material is homogenized,
The material for the core material was cut to a thickness of 21 mm, and the aluminum alloy for the brazing material was hot-rolled after the surface cutting to a thickness of 4.5.
After a brazing material having a thickness of 3 mm, the brazing material was superimposed on both sides of the core material and hot-rolled to obtain an aluminum alloy clad material having a thickness of 3 mm. Thereafter, cold rolling was performed and final annealing was performed to produce a 0.6 mm-thick aluminum alloy clad soft plate (temper 0) (cladding materials Nos. 1 to 16). In addition,
Brazing material A is JIS 4N04 equivalent, brazing material E is JIS
It is equivalent to 4045.

[0031]

[Table 1]

[0032]

[Table 2]

With respect to the aluminum alloy clad material (cladded materials No. 1 to 16) obtained as described above, (1) formability, (2) strength after brazing,
(3) Corrosion resistance and (4) Brazing property were evaluated. Table 3 shows the evaluation results. (1) Formability The aluminum alloy clad material was subjected to a tensile test to measure the elongation (%). In this test, an elongation of 20% or less was evaluated as insufficient moldability. That is, in the normal press forming of a core plate material for a drone cup type evaporator, when the elongation of the material is 20% or less, cracks are likely to occur during the processing.

(2) Strength after brazing The aluminum alloy clad material was heated under the same conditions as the brazing conditions, cooled, and then subjected to a tensile test. That is,
Regarding the vacuum brazing heat treatment method (VB), it is heated at 600 ° C. (material temperature) for 3 minutes in a vacuum (5 × 10 ⁻⁵ Torr or less), and the fluoride flux brazing heat treatment method (NB) As for the method, a fluoride-based flux (concentration: 3%) is applied to an aluminum alloy clad material, heated at 600 ° C. (material temperature) in a nitrogen gas atmosphere for 3 minutes, cooled, and subjected to a tensile test for each test material. Then, the tensile strength (MPa) was measured.

(3) Corrosion resistance A CASS test was performed for one month based on JIS H8681 for the aluminum alloy clad material obtained by the VB method and the NB method, respectively, and the maximum corrosion depth (mm) of the aluminum alloy clad material was determined. It was measured.

(4) Brazing properties The brazing properties were evaluated as follows: o, no local melting was observed by visual inspection and brazing properties were good, and local melting occurred and brazing properties were poor. Is indicated by x.

[0037]

[Table 3]

As can be seen from Table 3, the examples satisfying the conditions of the present invention (cladding materials Nos. 1 to 16) all have a large elongation of 23 to 27% and good moldability. Is shown. The strength after brazing is 125-
It exhibited excellent strength of 175 MPa. Corrosion resistance is CAS
The maximum corrosion depth after the S test was 0.14 to 0.28 mm, indicating good corrosion resistance. No local melting was observed during brazing, indicating good brazing properties. In addition, all of the test materials of this example were excellent in manufacturability without causing a problem in manufacturing.

Comparative Example 1 The compositions (core materials Nos. 7-14) shown in Table 1 were obtained by continuous casting.
An aluminum alloy for a core material having the composition shown in Table 2) and an aluminum alloy for a brazing material having the composition shown in Table 2 (composition shown in the brazing material Nos. X and Y) were ingots.
A soft plate of aluminum alloy clad material (temper 0) having a thickness of 0.6 mm was produced by the same process as that of (clad material No. 1).
7-28). The core 14 is equivalent to JIS A3003.

The obtained aluminum alloy clad material (cladding materials Nos. 17 to 28) was used in exactly the same manner as in Example 1 to (1) formability, (2) strength after brazing, and (3) Corrosion resistance and (4) brazing properties were measured and evaluated. Table 4 shows the evaluation results.

[0041]

[Table 4]

As shown in Table 4, Comparative Example 1 (cladding materials Nos. 17 to 28), which does not satisfy the conditions of the present invention, does not have the required performance as an aluminum alloy cladding material. That is, the clad material No. In No. 17, the Cu content of the core material is small, so the tensile strength is low, the maximum corrosion depth after the CASS test is large, and the corrosion resistance is poor. Cladding material No.
Sample No. 18 had a low elongation due to a high Cu content in the core material, resulting in insufficient moldability, and caused local melting by heating during brazing.

Clad material No. 19 and 20 are inferior in corrosion resistance due to high content of Si and Fe in the core material, and CA
A through hole was formed in the SS test. Cladding material No. 21 is
Poor corrosion resistance due to low content of Ti in core material, CA
A through hole was formed in the SS test. Cladding material No. 22 is
Since the content of Ti in the core material is large, rolling is difficult and manufacturing is difficult. Cladding material No. In No. 23, since the content of Mg in the core material was large, the elongation was small and the moldability was insufficient, and local melting occurred by heating during brazing.

Clad material No. 24 is JIS core
Corresponding to A3003 alloy material, the core material has a low Cu content, so the tensile strength is low, the core material has a low Ti content, and the core material has a high Si and Fe content.
Poor corrosion resistance, and a through hole was formed in the CASS test. Cladding material No. In Nos. 25 and 27, since the difference between the Cu content of the core material and the Cu content of the brazing material was as small as 0.07%, the corrosion resistance as an aluminum alloy clad material was inferior. Occurred. Cladding material No.
In Nos. 26 and 28, since the content of Cu in each core material is large, rolling is difficult and manufacturing is difficult.

Example 2 By continuous casting, an aluminum alloy for a core having the composition shown in Table 5 (the composition shown in Core Nos. 1 to 6), and
(Braze material No. A, B, C, D, E, F,
Aluminum alloys for brazing alloys having the compositions shown in Tables G and H) were respectively ingoted, and the aluminum alloy for the core material was homogenized, and the surface was cut into a core material having a thickness of 21 mm. Was hot-rolled to obtain a brazing material having a thickness of 4.5 mm, and then the brazing material was superimposed on both sides of the core material and hot-rolled to obtain an aluminum alloy clad material having a thickness of 3 mm. Thereafter, cold rolling was performed and final annealing was performed to prepare a 0.5 mm thick aluminum alloy clad soft plate (temper 0) (cladding materials Nos. 1 and 2).
0).

[0046]

[Table 5]

[0047]

[Table 6]

The aluminum alloy clad materials (cladding materials Nos. 1 to 20) obtained as described above were prepared according to the same method as in Example 1, (1) formability, (2) strength after brazing, and (3) The corrosion resistance and (4) brazing properties were evaluated.
Table 7 shows the evaluation results.

[0049]

[Table 7]

As can be seen from Table 7, Examples 2 (cladding materials Nos. 1 to 20) satisfying the conditions of the present invention have a large elongation of 25% or more and good moldability. Is shown. The strength after brazing is 125M
It exhibited excellent strength of Pa or more. As for the corrosion resistance, the maximum corrosion depth after the CASS test was as shallow as 0.10 mm to 0.16 mm, indicating that it was excellent. In the brazing, no local melting was observed, and the brazing properties were good. Further, in Example 2, all the materials had good manufacturability, and there was no problem in manufacturing.

Comparative Example 2 The compositions (core materials Nos. 7-14) shown in Table 5 were obtained by continuous casting.
And a composition shown in Table 6 [brazing material No. S, T, U, V, X, and Y) were ingoted into an aluminum alloy for brazing material, and the same process as in Example 2 was performed to form a 0.5 mm-thick aluminum alloy clad soft plate (not shown). Quality 0) was produced (cladding materials Nos. 21 to 34). The core 14 is made of JIS
A3003 equivalent product, brazing material S is JIS 4N04 equivalent product, and brazing material T is JIS 4045 equivalent product.

The obtained aluminum alloy clad material (clad material Nos. 21 to 34) was subjected to exactly the same method as in Example 2 above, (1) formability, (2) strength after brazing, and (3) Corrosion resistance and (4) brazing properties were measured and evaluated. Table 8 shows the evaluation results.

[0053]

[Table 8] Note: The # mark indicates that the corrosion consumption of the brazing material is large.

As shown in Table 8, Comparative Example 2 which does not satisfy the conditions of the present invention (cladding materials Nos. 21 to 34) does not have the required performance as an aluminum alloy cladding material. That is, the clad material No. Sample No. 21 has a low tensile strength due to a low content of Cu in the core material, has a large maximum corrosion depth after the CASS test, and is inferior in corrosion resistance. Cladding material No.
Sample No. 22 had a high Cu content in the core material, and therefore had low elongation and poor moldability, and caused local melting by heating during brazing. Cladding material No. Samples Nos. 23 and 24 were inferior in corrosion resistance due to the high content of Si and Fe in their respective core materials, and formed through holes in the CASS test.

Clad material No. In No. 25, since the content of Ti in the core material was small, the corrosion resistance was poor, and a through hole was formed in the CASS test. Cladding material No. In No. 26, since the core material contains a large amount of Ti, rolling is difficult and manufacturing is difficult. Cladding material No. 27 has a high Mg content in the core material,
Elongation was small and molding workability was insufficient, and local melting occurred by heating during brazing. Cladding material No. In No. 28, the core material corresponds to the JIS A3003 alloy material, and since the Cu content of the core material is small, the tensile strength is low, the Ti content of the core material is small, and the Si and Fe of the core material are further reduced. , The corrosion resistance was poor, and a through hole was formed in the CASS test.

Clad material No. In Nos. 29 and 32, since the content of Zn, In, and Sn in the brazing material was small, the sacrificial anode effect of the brazing material portion was insufficient, the maximum corrosion depth after the CASS test was deeper than that in Example 2, and the corrosion resistance was low. Is inferior. Cladding material No. In Nos. 30, 31, 33 and 34, each of the brazing materials has a large content of Zn, In, and Sn, so that the brazing material portion of the clad material is significantly corroded and consumed, and the sacrificial anode effect of the brazing material portion can be maintained for a long time. However, the maximum corrosion depth after the CASS test was deeper than in Example 2, and the corrosion resistance was poor.

[0057]

According to the present invention, by adjusting the combination of the contents of Cu and Mg, the elongation of the material before brazing is increased, and the formability is ensured. To improve the strength characteristics of the steel, restrict the content of Si and Fe,
The inclusion of Ti improves the self-corrosion resistance of the core material.
By adjusting the amount of Zn, In, and Sn added to the brazing material, the sacrificial anode effect is sufficiently exerted on the brazing material, and the corrosion resistance of the clad material is improved. In particular, the brazing material has excellent corrosion resistance and brazing properties. Provided is an aluminum alloy clad material for a heat exchanger, which has excellent formability before forming, has high strength after brazing, and has excellent corrosion resistance and strength. By using the aluminum alloy clad material for a heat exchanger, the thickness of the working fluid passage material can be reduced, and the weight and the life of an aluminum heat exchanger such as an evaporator, a radiator, and a condenser can be achieved.

[Brief description of the drawings]

FIG. 1 is a perspective view of a drone cup type evaporator to which an aluminum alloy clad material for a heat exchanger according to an embodiment of the present invention can be applied.

FIG. 2 is a front view of FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Drone cup type evaporator 2, 3 Core plate 4 Aluminum alloy fin 5 Working fluid passage

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C22C 21/00 C22C 21/00 D F28F 21/08 F28F 21/08 A

Claims (6)

[Claims] 1. An aluminum alloy clad material in which a brazing material is clad on one or both surfaces of a core material, wherein the core material has a Cu content of more than 0.6% (weight%, the same applies hereinafter), a content of 1.2% or less, and a Si content of 0.2% or less. % Or less, Fe: 0.3% or less, Ti: 0.06% or more
An aluminum alloy for a heat exchanger having excellent corrosion resistance and strength, characterized by comprising an aluminum alloy containing 0.35% and the balance being Al and impurities, wherein the brazing material is constituted by an Al-Si-based aluminum alloy. Clad material. 2. The brazing filler metal contains Cu: 0.06% to 1.0%, and the Cu content of the brazing filler metal (γ ₁ %)
The value obtained by subtracting the content (γ ₂ %) is 0.2% or more (γ ₁ −
_{2. The} aluminum alloy clad material for a heat exchanger according to claim 1, wherein the aluminum alloy clad material is made of an Al-Si-based aluminum alloy satisfying? ₂ ? 0.2%). 3. The brazing material further comprises Zn: 0.3% to 4.0%,
2. The corrosion resistance and strength according to claim 1, wherein the alloy is made of an Al-Si-based aluminum alloy containing at least one of In: 0.005% to 0.1% and Sn: 0.01% to 0.1%. Excellent aluminum alloy clad material for heat exchangers. 4. An aluminum alloy clad material in which a brazing material is clad on one or both surfaces of a core material, wherein the core material has a Cu content of more than 0.6% to 1.2% or less, a Si content of 0.2% or less,
e: 0.3% or less, Ti: 0.06% to 0.35%, Mg: 0.06% to
An aluminum alloy for a heat exchanger having an excellent corrosion resistance and strength, characterized by being composed of an aluminum alloy containing 0.5% and the balance being Al and impurities, wherein the brazing material is composed of an Al-Si-based aluminum alloy. Clad material. 5. The brazing material contains Cu: 0.06% to 1.0%, and the Cu content of the core material (γ ₁ %)
The value obtained by subtracting the content (γ ₂ %) is 0.2% or more (γ ₁ −
The aluminum alloy clad material for a heat exchanger having excellent corrosion resistance and strength according to claim 4, wherein the aluminum alloy clad material is made of an Al-Si based aluminum alloy satisfying? ₂ ? 0.2%). 6. The brazing material further comprises Zn: 0.3% to 4.0%,
The corrosion resistance and strength according to claim 4, characterized in that it is made of an Al-Si-based aluminum alloy containing at least one of In: 0.005% to 0.1% and Sn: 0.01% to 0.1%. High-strength aluminum alloy clad material for heat exchangers with excellent performance.