JP2000202682A - Aluminum alloy brazing filler metal and aluminum alloy clad material for heat exchanger excellent in brazability and corrosion resistance using the brazing filler metal for clad material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an aluminum alloy brazing filler metal, which has excellent brazability in brazing with using, in particular, fluoride group flux, and an aluminum alloy clad material for a heat exchanger, which is excellent in brazability and corrosion resistance, is capable of improving strength after brazing, thinning a working fluid passage material, reducing a weight of the aluminum alloy heat exchanger and extending a life. SOLUTION: An aluminum brazing filler metal is an Al-Si group alloy containing 6-14% Si, 0.006-0.7% Fe, further a Mg content regulated to <=0.004%, a Ca content regulated to <=0.006%, an aluminum alloy clad material is a material where a brazing filler metal is cladded on one face or both faces of a core material, a core material is an aluminum alloy containing 0.5-2.0% Mn, 0.1-1.0% Cu, 0.11-1.0% Si, further a Fe content regulated to <=0.3%, a Mg content regulated to <=0.04%, and the balance Al with impurities.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an aluminum alloy brazing material, and an aluminum alloy clad material for a heat exchanger having excellent brazing properties and corrosion resistance using the brazing material as a cladding material, and more specifically, an evaporator or a radiator for a car air conditioner. , A brazing material used for brazing an aluminum alloy heat exchanger, particularly a brazing material suitably used for brazing in an inert gas atmosphere using a fluoride-based flux, and the heat produced by brazing The present invention relates to an aluminum alloy clad material for a heat exchanger having excellent brazing properties and corrosion resistance used as a constituent material of a working fluid passage of an exchanger.

[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.

As shown in FIGS. 1 and 2, for example, a drone cup type evaporator 10 has core plates 11 and 1 made of press-formed aluminum alloy clad material.
2 and aluminum alloy fin 13 corrugated
And the core plates 11 and 12 are brazed.
The fins 13 are joined to the core plates 11 and 12 by melting the brazing material, and a working fluid passage 14 for a refrigerant or the like is formed between the core plates 11 and 12.

[0004] The core plates 11 and 12 are made of Al-Mn, Al-Mn-Cu, Al-Mn.
Aluminum alloys containing Mn, such as -Mg-based and Al-Mn-Cu-Mg-based alloys, for example, JIS A3003 alloy and 3005 alloy are used.
System, Al-Si-Mg system, Al-Si-Mg-Bi system,
Al-Si-Mg-Be system, Al-Si-Bi system, Al
Al- such as -Si-Be type, Al-Si-Bi-Be type
An Si alloy or the like is used, and an aluminum alloy clad material obtained by cladding the above brazing material on one or both surfaces of the above core material is used.

As the fins 13, an aluminum alloy obtained by adding Cu, Mg, Zn, Sn, In or the like to an Al-Mn alloy is used. A brazing method for the fins 13 and the core plates 11 and 12 is used. In general, a brazing method using a fluoride-based flux in an inert gas atmosphere is applied in terms of environmental problems and costs, but vacuum brazing may be applied in some cases.

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, in order to reduce the thickness of the aluminum alloy clad material constituting the working fluid passage, if various elements are added and the strength is increased, the corrosion resistance is reduced, and the brazing becomes difficult as the material becomes thinner, and heat exchange becomes difficult. Vessel manufacturability,
Since a problem arises in durability, there is a demand for the development of a clad material with further improved brazing properties and corrosion resistance.

The aluminum alloy clad material conventionally used as the core plates 11 and 12 of the drone cup type evaporator 10 has a core material of an aluminum alloy containing Mn as described above, and has a pitting corrosion resistance. For example, when applied to a working fluid passage material of a refrigerant, the penetration leakage accident due to pitting has been experienced.

In order to improve the pitting resistance of the working fluid passage material, the fins 13 are made of a material having a potential lower than that of the working fluid passage material, for example, Al-Mn-Zn, Al-M.
It is conceivable to apply an n-Sn-based alloy, an Al-Mn-In-based alloy, or the like, and to use the sacrificial anode effect of the fins 13 made of these materials to prevent corrosion of the working fluid passage material.
This anticorrosion method is effective only for the working fluid passage material near the joint with the fin 13, and the sacrifice anode effect of the fin 13 does not reach the working fluid passage material at a position away from the fin 13, and pitting occurs. Inevitable.

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 a core material (Japanese Patent Publication 6-4)
No. 1621), the content of Fe, which constitutes a compound serving as a cathode among the core material components and degrades 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 respectively limited to improve intergranular corrosion resistance (Japanese Patent Publication No. 6-41621) has been proposed. The proposed aluminum alloy clad material is
Although the corrosion resistance is improved to some extent, there is a problem that the strength characteristics after brazing are not sufficiently improved and the pressure resistance of the heat exchanger is reduced.

As an effective means for improving the strength characteristics of the clad material, there is addition of Mg to the Al-Mn alloy core material, but a fluoride-based flux is used for the clad material comprising the Mg-containing core material. In the case of brazing, the Mg in the core material diffuses to the surface in the brazing process and reacts with F in the flux to form an MgF ₂ compound, and the amount of flux effectively acting in brazing decreases. In addition, there is a problem that the effect of removing the oxide film from the flux is reduced and the brazing property is impaired.

[0011] In the brazing of an aluminum alloy brazing material, in particular, in brazing using a fluoride-based flux, good brazing can be performed even for a thinned heat exchanger constituent material, thereby reducing the manufacturing cost of the heat exchanger. Therefore, development of an improved brazing material capable of achieving stable brazing even with a reduced flux consumption has been desired.

[0012]

SUMMARY OF THE INVENTION The present invention solves the above-mentioned conventional problems in an aluminum alloy brazing material and a working fluid passage material which are particularly suitable for brazing using a fluoride-based flux. In order to obtain an aluminum alloy clad material that satisfies the requirement for thinning of the brazing material, the composition of the brazing material with respect to the brazing properties and the corrosion resistance of the brazed heat exchanger constituent material, the core of the clad material using the brazing material as a cladding material About the composition of the material and the effect of its combination,
It was made as a result of conducting experiments and studies from various angles, and the purpose was to use an aluminum alloy brazing material with excellent brazing properties, and to use the brazing material as a skin material, with good brazing properties and corrosion resistance. Another object of the present invention is to provide an aluminum alloy clad material for a heat exchanger having improved strength after brazing.

[0013]

According to the first aspect of the present invention, there is provided an aluminum alloy brazing material containing 6 to 14% of Si and 0.06 to 0.7% of Fe,
Is regulated to 0.04% or less, the Ca content is regulated to 0.006% or less, and the balance consists of Al and impurities.

Further, the aluminum alloy brazing material according to claim 2 is the same as the brazing material according to claim 1, further comprising Bi: 0.01 to 0.4.
%. The brazing filler metal according to claim 3 is the same as the brazing filler metal according to claim 1 or 2, further comprising: Zn: 0.3 to 4.0.
%, In: 0.005 to 0.1%, and Sn: 0.01 to 0.1%.

[0015] The aluminum alloy clad material according to claim 3 is used as a skin material on one or both surfaces of the core material.
An aluminum alloy clad material clad with the brazing material according to any one of the above, wherein the core material is Mn: 0.5% to 2.
0%, Cu: 0.1% to 1.0%, Si: 0.11 to 1.0%, Fe content as impurities is restricted to 0.3% or less, Mg content is regulated to 0.04% or less. Characterized by being composed of an aluminum alloy
An aluminum alloy clad material according to a fourth aspect is characterized in that, in the aluminum alloy clad material according to the third aspect, the core material further contains Ti: 0.06 to 0.35%.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The significance of the alloy components in the aluminum alloy brazing material of the present invention and the reasons for limiting the same will be described. (1) Components of brazing material The brazing material differs depending on the brazing method. For example, in the case of flux brazing, an Al-Si alloy is used, and in the case of vacuum brazing, an Al-Si-Mg alloy or Al −
A Si-Mg-Bi alloy or the like is used.
The content of i is preferably in the range of 6% to 14%.

[0017] Fe has the effect of refining the structure of the brazing material and increasing the fluidity of the brazing material. The preferred content of Fe is
If the content is less than 0.06%, the effect is not sufficient. If the content exceeds 0.7%, the effect is saturated and A becomes a cathode with respect to the Al matrix.
The production amount of the l-Fe compound increases and the corrosion resistance decreases.

In the case of brazing using a fluoride-based flux, Mg is concentrated on the surface of the brazing material and reacts with fluorine (F) in the flux to form an MgF ₂ compound in a brazing process. Since the amount of flux effectively acting in brazing is reduced to reduce the effect of removing the oxide film of the flux and impair brazing properties, the content of Mg is preferably regulated to 0.04 or less, more preferably to 0.02% or less.

Since Ca in the brazing material constitutes a dense oxide on the surface of the brazing material, it lowers the wettability and spreadability of the brazing material and impairs the brazing property. The preferred content of Ca is in the range of 0.006% or less, and if it exceeds 0.006%, the brazing property is significantly reduced. The more preferred content of Ca is in the range of 0.004% or less.

Bi lowers the melting point of the wax and improves the wettability and flowability of the wax. The preferred content of Bi is 0.01
% To 0.4%, the effect is small when it is less than 0.01%, and when it exceeds 0.4%, the effect is saturated and the self-corrosion resistance is lowered. A more preferred content range is
0.1 to 0.4%.

Zn, In, and Sn lower the potential of the brazing material, provide a sacrificial anode effect to the core material, and improve the corrosion resistance of the clad material. The preferred content is Zn: 0.3%
4.0%, In: 0.005% to 0.1%, Sn: 0.01% to 0.1%
If the respective amounts are less than the lower limits, the effect is not sufficient. If the respective amounts exceed the upper limits, the corrosion and wear of the brazing material portion of the clad material is remarkable, and the sacrificial anode effect of the brazing material portion is not maintained for a long period of time. The self-corrosion resistance of the attached portion is also reduced.

In the brazing material, a small amount of, for example, 0.1% or less of Be, Sr, L
One or more of i and Na can be contained. Also, Mn, Cu, Ti, Cr, Zr, N
An element such as i may be contained in the brazing material in a small amount for the purpose of improving the strength of the brazing material as long as the effect of the present invention is not impaired. However, when the content of these elements increases,
Since the self-corrosion resistance of the brazing material decreases, the total content of these elements is preferably suppressed to 1% or less.

The significance of the alloy components in the aluminum alloy clad material for a heat exchanger of the present invention and the reasons for the limitations will be described. (2) Components of core material Mn in the core material functions to improve the strength of the clad material. The preferred range of Mn content is 0.5% to 2.0%. If the content is less than 0.5%, the effect is small. If the content exceeds 2.0%, a coarse compound is produced at the time of casting, which impairs the rolling processability. It is difficult to obtain a suitable clad material.

Cu in the core material functions to enhance the strength of the clad material, increase the potential of the core material, increase the potential difference between the brazing material layer and the fin material, and enhance the anticorrosion effect. The preferred range of Cu content is 0.1% to 1.0%. If the Cu content is less than 0.1%, the effect is small. If the Cu content exceeds 1.0%, the core material may be melted at the time of brazing. Also has poor corrosion resistance.

The Si in the core material increases the strength of the clad material. A preferred content range is 0.11 to 1.0%. If the content is less than 0.11%, the effect is not sufficient. If the content exceeds 1.0%, the core material may be melted during brazing, and the corrosion resistance of the core material is reduced. .

Since Fe acts as a cathode with respect to the aluminum base material and reduces the corrosion resistance, it is preferably restricted to 0.3% or less. However, a high-purity aluminum ingot having a very small Fe content is expensive and impractical, so it is more preferably in the range of 0.01 to 0.3% or less.

In the case of brazing using a fluoride-based flux, Mg in the core material diffuses to the surface in the brazing process and reacts with F in the flux to form an MgF ₂ compound. The amount of effectively acting flux is reduced, and the effect of removing the oxide film of the flux is reduced, thereby impairing the brazing property. Therefore, the Mg content is 0.
It is preferable to regulate it to 04% or less. More preferably 0.
02% or less.

[0028] Ti functions to improve the corrosion resistance of the core material. That is, Ti is divided into a high-concentration region and a low-concentration region, and they are alternately distributed in the thickness direction to form a layer. The low-Ti concentration region corrodes preferentially as compared with the high-concentration region. As a result, the progress of corrosion in the thickness direction is prevented, and the pitting resistance of the material is improved. The preferable content range of Ti is 0.06 to 0.35%,
If it is less than 06%, the effect is small, and if it exceeds 0.35%, a coarse compound is formed at the time of casting, and it becomes difficult to roll the material.

In addition, impurity elements such as Zn, Cr, and Zr may be contained in the core material within a range that does not impair the effects of the present invention. However, Zn makes the potential of the core material low, reduces the potential difference with the fin material, and impairs the corrosion resistance.
It is preferable to set the following. Although Cr and Zr have the effect of making the structure finer, they impair workability. Therefore, each of them is preferably limited to 0.3% or less.

The aluminum alloy clad material of the present invention comprises:
The aluminum alloy constituting the core material and the brazing material is ingot-formed by, for example, continuous casting, homogenized, or homogenized, and then hot-rolled to a predetermined thickness. According to the method, the clad material is formed by hot rolling, finally cold-rolled to a predetermined thickness, and finally subjected to annealing. In addition, the aluminum alloy brazing material of the present invention is used as a brazing material for a brazing material used for joining various components by being processed into a predetermined shape such as a plate material or a wire material, in addition to being applied as a cladding material. Can also be suitably used.

The aluminum alloy clad material of the present invention is
For example, as shown in FIGS. 1 and 2, the clad material is press-molded into core plates 11 and 12 to be used as a constituent member of a drone cup type evaporator. Then, a fin 13 made of aluminum alloy is brazed and joined to assemble a drone cup type evaporator. To make a tank material such as a radiator or a capacitor, the 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 to both brazing joints. Vacuum brazing can also be applied.

[0032]

EXAMPLE 1 An aluminum alloy for core material (JIS 3) was produced by continuous casting.
003) and an aluminum alloy for a brazing filler metal having the composition shown in Table 1 (brazing filler metals having compositions shown in Nos. 1 to 22). The aluminum alloy for brazing material is hot-rolled and then hot-rolled into a 3 mm thick brazing material, and the aluminum alloy for brazing material is coated on both sides of the core material. A brazing material was overlapped as a material and hot-rolled to obtain a clad material having a thickness of 3 mm. Thereafter, cold rolling was performed to obtain a plate having a thickness of 1.0 mm, and final annealing was performed to produce a soft plate (O-finished) of a clad material (brazing sheet). (Clad material Nos. 1 to 22)

[0033]

[Table 1]

The clad material (cladded materials Nos. 1 to 22) obtained as described above was subjected to the following method.
(1) Brazing properties and (2) corrosion resistance were evaluated. (1) Brazing property As shown in FIG. 3, an aluminum alloy clad material 2 in which brazing materials 4 and 5 are clad on both surfaces of a core material 6 has a width of 20 mm.
mm and a length of 40 mm, and this was placed on a 3003 alloy material (cut to a width of 25 mm, a length of 40 mm, and a thickness of 2 mm) 3 to form an inverted T-shaped joint 1. After applying the compound flux (concentration 1%),
Brazing heat treatment was performed in a nitrogen gas atmosphere at a temperature of 600 ° C. for 5 minutes. As shown in FIG. 4, fillet portions 7 and 8 are melt-formed at the corners of the inverted T-shaped joint 1 after the treatment, so that the cross-sectional areas of these fillet portions 7 and 8, A ₁ and A ₂ and measure the cross-sectional area A ₁
And the cross-sectional area of the brazing material 4 and 5 of the front A ₂ take it with heat, from the ratio of the A ₀₁ and A _02, the flow coefficient K = (A ₁ +
To calculate the _{A 2) / (A 01 +} A 02). The larger the flow coefficient K, the greater the proportion of the brazing material that has melted, indicating that the flowability of the brazing material is good and the brazing property is excellent. In the brazing of a brazing sheet for an ordinary heat exchanger for automobiles, if the flow coefficient K is less than 0.35, poor brazing properties such as cut-out of fillets are likely to occur. When the K was 0.35 or more, the brazing property was good (）), and when the K was less than 0.35 or the fillet was actually cut, the brazing property was insufficient (x).

(2) Corrosion resistance Regarding the inverted T-shaped joint 1 after the above-mentioned brazing and heating, C
The ASS test was performed for two weeks based on JIS8681 and the maximum corrosion depth of the general portion (the portion other than the fillet portion) of the clad material after the test was measured. Further, the corrosion state of the brazed joint fillet after the corrosion test was investigated, and the test material in which 50% or more of the fillet area disappeared due to corrosion was evaluated as having insufficient corrosion resistance (x). Those having a corroded portion of less than 25% of the fillet area (◎) and those having a corrosion area of 25% or more and less than 50% (○) were evaluated as having good corrosion resistance.

Table 2 shows the evaluation results. As can be seen from Table 2, the examples satisfying the conditions of the present invention (cladding material No.
1 to 22) all exhibited excellent brazing properties with a flow coefficient K of 0.40 or more. The maximum corrosion depth after the CASS test was 0.25 to 0.5 mm, indicating good corrosion resistance. In addition, all of the test materials of this example were excellent in manufacturability without causing a problem in manufacturing.

[0037]

[Table 2]

Comparative Example 1 Aluminum alloy for core material (JIS 3
003) and an aluminum alloy for a brazing filler metal having the composition shown in Table 3 (the brazing filler metals having the compositions shown in Nos. 23 to 33) were ingoted, and an aluminum alloy clad having a thickness of 1.0 mm was formed in the same process as in Example 1. A soft plate (O-tempered) of the material was produced (cladding materials Nos. 23 to 33).

[0039]

[Table 3]

The obtained aluminum alloy clad materials (clad materials Nos. 23 to 33) were evaluated for (1) brazing properties and (2) corrosion resistance in exactly the same manner as in Example 1 above. Table 4 shows the evaluation results.

[0041]

[Table 4] << Table note >> Flow coefficient *: Fillet cut

As shown in Table 4, the cladding materials (cladding materials Nos. 23 to 3) according to the comparative examples which did not satisfy the conditions of the present invention.
No. 3) does not have the required performance as an aluminum alloy clad material for a heat exchanger. That is, the clad material No. In No. 23, since the content of Si in the brazing material is small, the flow coefficient K is small and the brazing property is inferior. Cladding material No. In No. 24, since the content of Si in the brazing material was too large, rolling workability was poor and a sound clad material could not be produced. Cladding material No. In No. 25, since the content of Fe in the brazing material is small, the flow coefficient K is small, and the brazing property is inferior. Cladding material No. In No. 26, since the content of Fe in the brazing filler metal was large, the corrosion resistance was poor, the maximum corrosion depth after the CASS test was large, and the self-corrosion of the fillet portion was severe.

The clad material No. In No. 27, since the content of Mg in the brazing material was large, the brazing property was inferior, a sufficient fillet was not formed during brazing, and the fillet was cut. Cladding material No. In No. 28, since the content of Ca in the brazing material was large, the brazing property was poor, and sufficient fillets were not formed during brazing, and the fillets were cut. Cladding material No. No. 29 has a large Bi content in the brazing material, and the clad material No. 29 has a high Bi content. No. 30 has a high Zn content in the brazing material, and the clad material No. 30 has a high Zn content. No. 31 has a high In content in the brazing material, and clad material No. 31 has a high In content. 32 is S in brazing material
Since the content of n is large, in any case, the self-corrosion of the fillet portion is severe in the CASS test, and the corrosion resistance is poor. Cladding material No. Reference numeral 33 denotes Bi, Zn, In, Sn in the brazing material.
, The effect of each additive element was not observed, and the cladding material (cladding N
o. Only performance equivalent to 1) is shown.

Example 2 By continuous casting, an aluminum alloy for a core material having a composition shown in Table 5 (No. 34 to 49) and an aluminum alloy for a brazing material having a composition shown in Table 6 (No. 34 to 4)
4) The aluminum alloy for core material is cast and the ingot is homogenized and then chamfered to a thickness of 21 mm to obtain a core material. For the aluminum alloy for brazing material, the ingot is chamfered. After hot-rolling to form a brazing material having a thickness of 4.5 mm, a brazing material as a cladding material was superimposed on both surfaces of the core material and hot-rolled to obtain a cladding material having a thickness of 3 mm. Thereafter, the sheet is subjected to cold rolling to obtain a sheet having a thickness of 0.5 mm, and is subjected to final annealing, so that a soft sheet of a clad material (brazing sheet) (O
Temper) was prepared. (Clad material Nos. 34 to 58)

With respect to the obtained aluminum alloy clad material (cladded materials Nos. 34 to 58), (1) brazing properties, (2) corrosion resistance (the test period was 4 weeks), in exactly the same manner as in Example 1 above. ) Was evaluated. further,
(3) Fluoride flux (concentration 1%) for clad material
Was applied and subjected to a brazing heat treatment of heating at a temperature of 600 ° C. for 5 minutes in a nitrogen gas atmosphere, and then a tensile test was performed at room temperature to evaluate the strength after brazing. Tables 7 and 8 show the evaluation results.

[0046]

[Table 5]

[0047]

[Table 6]

[0048]

[Table 7]

[0049]

[Table 8]

As can be seen from Tables 7 and 8, the clad material No. All of Nos. 34 to 58 exhibited excellent brazing properties with a flow coefficient K of 0.40 or more. Maximum corrosion depth of general part after CASS test is 0.16 ~ 0.30mm
And has excellent corrosion resistance. Less corrosion of fillet. Moreover, the tensile strength equivalent after brazing is 137MPa.
a or more, showing excellent strength. These clad materials had good workability, and did not cause any trouble in the production of the clad materials.

Comparative Example 2 By continuous casting, an aluminum alloy for a core material having a composition shown in Table 9 (No. 50 to 65) and an aluminum alloy for a brazing material having a composition shown in Table 10 (No. 45 to 5)
4) The aluminum alloy for core material is cast and the ingot is homogenized and then chamfered to a thickness of 21 mm to obtain a core material. For the aluminum alloy for brazing material, the ingot is chamfered. After hot-rolling to form a brazing material having a thickness of 4.5 mm, a brazing material as a cladding material was superimposed on both surfaces of the core material and hot-rolled to obtain a cladding material having a thickness of 3 mm. Thereafter, the sheet is subjected to cold rolling to obtain a sheet having a thickness of 0.5 mm, and is subjected to final annealing, so that a soft sheet of a clad material (brazing sheet) (O
Temper) was prepared. (Clad material No. 59-84)

With respect to the obtained aluminum alloy clad material (clad material No. 59 to 84), (1) brazing property, (2) corrosion resistance, and (3) after brazing, in exactly the same manner as in Example 3 above. The strength was evaluated. Table 11 shows the results.
And Table 12.

[0053]

[Table 9]

[0054]

[Table 10]

[0055]

[Table 11] << Table note >> Flow coefficient *: Fillet cut

[0056]

[Table 12] << Table note >> Flow coefficient *: Fillet cut

As shown in Tables 11 to 12, the cladding material N
o. 59, no. No. 66 is inferior in strength after brazing because the Mn content of the core material is low. Cladding material No. 60, no.
In No. 67, since the Mn content of the core material was large, the workability was poor and rolling was difficult. Cladding material No. 61, no. 68
Since the Cu content of the core material is small, the strength is inferior and the corrosion depth of the general portion is large. Cladding material No. 62, No. 69
In Example 2, since the amount of Cu in the core material was large, local melting occurred during brazing heating. Cladding material No. 63, no. 70
Is inferior in strength because the amount of Si in the core material is small. Cladding material No. 64, no. 71 has a large amount of Si in the core material,
Local melting occurred during brazing heating. Cladding material N
o. 65, no. In No. 72, since the amount of Fe in the core material was large, the corrosion resistance was poor, and a through hole was formed in the corrosion test. The clad material No. In No. 65, since the amount of Mg in the core material was large, a sufficient fillet was not formed by brazing heating, and the fillet was cut. No. No. 73 has a small amount of Ti in the core material, and is inferior in corrosion resistance to the Ti-containing clad materials (Nos. 47 to 58). Cladding material No. In No. 74, since the amount of Ti in the core material was large, rolling was difficult and a sound clad material could not be produced.

The clad material No. 75 is Si in brazing material
, The flow coefficient K is small, and the brazing property is inferior. Cladding material No. In No. 76, since the content of Si in the brazing material was too large, rolling workability was poor and a sound clad material could not be produced. Cladding material No. 77 is
Since the content of Fe in the brazing material is small, the flow coefficient K is small, and the brazing property is inferior. Cladding material No. No. 78 is inferior in corrosion resistance due to the high content of Fe in the brazing material,
The maximum corrosion depth after the ASS test is large, and the self-corrosion of the fillet is also severe.

Further, the clad material No. In No. 79, since the content of Mg in the brazing material was large, the brazing property was poor, sufficient fillets were not formed during brazing, and the fillets were cut. Cladding material No. In No. 80, since the Ca content of the brazing material was large, the brazing properties were poor, and sufficient fillets were not formed during brazing, and the fillets were cut. Cladding material No. No. 81 has a high Bi content in the brazing material, and the clad material No. 81 has a high Bi content. No. 82 has a high Zn content in the brazing material, and clad material No. No. 83 has a high In content in the brazing material, and clad material No. 84 is S in brazing material
Since the content of n is large, in any case, the self-corrosion of the fillet portion is severe in the CASS test, and the corrosion resistance is poor.

[0060]

According to the present invention, an aluminum alloy brazing material having good brazing properties, particularly in brazing using a fluorinated flux, and good brazing properties and corrosion resistance, and strength after brazing An aluminum alloy clad material for a heat exchanger having improved properties is provided. According to the aluminum alloy clad material for a heat exchanger, the thickness of the working fluid passage material can be reduced, and the weight and life of an aluminum heat exchanger such as a radiator or a condenser can be reduced.

[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.

FIG. 3 is a cross-sectional view showing a state of a brazing property verification test (before brazing heating) of the aluminum alloy clad material for a heat exchanger according to the embodiment of the present invention.

FIG. 4 is a cross-sectional view showing a state of a brazing property verification test (after brazing heating) of the aluminum alloy clad material for a heat exchanger according to the embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Inverted T-shaped joint 2 Aluminum alloy clad material 3 3003 alloy material 4, 5 Brazing material 6 Core material 7, 8 Fillet part 10 Drone cup type evaporator 11, 12 Core plate 13 Aluminum alloy fin 14 Working fluid passage

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

Claims (5)

[Claims] 1. Si: 6 to 14% (% by weight, hereinafter the same), F
e: An aluminum alloy brazing filler metal containing 0.06 to 0.7%, the content of Mg is restricted to 0.04% or less, the content of Ca is restricted to 0.006% or less, and the balance consists of Al and impurities. 2. The aluminum alloy brazing material according to claim 1, further comprising Bi: 0.01 to 0.4%. 3. Further, Zn: 0.3-4.0%, In: 0.005%
The aluminum alloy brazing material according to claim 1 or 2, comprising one or more of 0.1 to 0.1% and Sn: 0.01 to 0.1%. 4. An aluminum alloy clad material in which the brazing material according to any one of claims 1 to 3 is clad as a skin material on one or both surfaces of the core material, wherein the core material is Mn:
0.5% to 2.0%, Cu: 0.1% to 1.0%, Si: 0.11 to 1.0
%, The content of Fe as an impurity is controlled to 0.3% or less, and the content of Mg is controlled to 0.04% or less. Aluminum alloy clad material for heat exchangers with excellent corrosion resistance. 5. The aluminum alloy clad material for heat exchangers according to claim 4, wherein the core material further contains Ti: 0.06 to 0.35%.