JP2013091840A - Side support material and method for producing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a side support material which, when brazed to a fin, exhibits little erosion to the fin by brazing and is excellent in erosion resistance, and a method for producing the same.SOLUTION: The side support material 5 is obtained when one surface of a core material, which comprises 1.0-2.0 mass% of Mn, 0.5-1.5 mass% of Si, 0.3-1.2 mass% of Cu, and 0.03-0.3 mass% of Mg, with the balance of Al and unavoidable impurities, is clad in a brazing material, which comprises 3.0-9.0 mass% of Si, with the balance of Al and unavoidable impurities, and the other surface of the core material is clad in a diffusion prevention layer, which comprises 1.0-2.0 mass% of Mn, 0.3-1.7 mass% of Si, and 0.03-0.25 mass% of Cu, with the balance of Al and unavoidable impurities.

Description

  The present invention relates to a side support material and a manufacturing method thereof.

  Aluminum heat exchangers for automobiles use aluminum alloy tubes, fins, and side supports, which are assembled by brazing. Thinning of fins and tubes has been progressing for the purpose of weight reduction, and accordingly, it is necessary to increase the strength after brazing in order to ensure the pressure resistance of the heat exchanger. In particular, since the aluminum alloy side support material has a great influence on the pressure resistance of the heat exchanger, a high strength side support material has been proposed so far (see, for example, Patent Document 1).

JP 2005-15857 A

  As mentioned above, fins tend to be thinner for the purpose of weight reduction, and when brazing a brazing sheet with a large amount of brazing material, such as side support material, and brazing, and fin material, A problem has arisen in which erosion with buckling occurs. In addition, in order to secure the pressure resistance of heat exchangers using thinned fins and tubes, the side support after brazing needs to have high strength.

  The present invention has been made in view of such circumstances, and when brazed to a fin, there is little brazing erosion to the fin, excellent erosion resistance, and high strength after brazing. An object is to provide a side support material and a manufacturing method thereof.

  The side support material of the present invention has Mn: 1.0 to 2.0 mass%, Si: 0.5 to 1.5 mass%, Cu: 0.3 to 1.2 mass%, Mg: 0.03 to 0 3% by mass, on one side of a core material composed of an aluminum alloy composed of the balance Al and inevitable impurities, Si: 3.0 to 9.0% by mass, composed of an aluminum alloy composed of the balance Al and inevitable impurities The brazing material is clad, and the other surface of the core material is Mn: 1.0-2.0 mass%, Si: 0.3-1.7 mass%, Cu: 0.03-0.25 mass% The diffusion prevention layer made of an aluminum alloy composed of the remaining Al and inevitable impurities is clad.

In the side support material of the present invention, the core material may further contain one or two of Zr: 0.05 to 0.25% by mass and Ti: 0.03 to 0.20% by mass. preferable.
In the side support material of the present invention, it is preferable that the diffusion preventing layer further contains Zn: 0.05% by mass or more and less than 0.5% by mass.
In the side support material of the present invention, it is preferable that a crystal grain size of the core material after brazing is 200 μm or less.
In the side support material of the present invention, it is preferable that the average equivalent-circle diameter of the Si particles in the brazing material is 2 μm or less.

  The method for producing a side support material of the present invention is a method for producing the side support material of the present invention, wherein the core material of the side support is 550 ° C. or more and 610 ° C. or less and 1 hour or more and 10 hours or less. It is characterized in that it is produced by a production method that implements the above, or a production method that does not carry out homogenization.

The side support material according to the present invention is clad with brazing material containing Si with a predetermined content on one surface of a core material containing Mn, Si, Cu, Mg with a predetermined content, and on the other surface. Since the diffusion preventing layer containing Mn, Si, and Cu at a predetermined content is clad, when brazed to the fin, the braze erosion to the fin is small and the erosion resistance is excellent.
Further, in the side support material according to the present invention, by defining the crystal grain size after brazing of the core material to 200 μm or less, the brazing erosion to the core material of the side support is promoted when brazed to the fin, Wax erosion is suppressed.
Furthermore, in the side support material according to the present invention, by regulating the average equivalent circle diameter of the Si particles in the brazing material to 2 μm or less, the brazing erosion to the fin is more effectively suppressed when brazed to the fin. it can.
The side support material manufacturing method of the present invention is manufactured by a manufacturing method in which a homogenization process is performed in which the core material of the side support is 550 ° C. or more and 610 ° C. or less and 1 hour or more and 10 hours or less, or a manufacturing method that does not perform the homogenization process Thus, the crystal grain size of the core material of the side support material can be reduced. Therefore, during the brazing heat treatment when brazing the side support material manufactured by the method according to the present invention to the fin, the brazing erosion to the core material of the side support material is increased, and the brazing erosion to the fin is suppressed. be able to.

It is a perspective view showing one embodiment of a heat exchanger using the side support material concerning the present invention. It is a front view of the heat exchanger shown in FIG. It is a schematic diagram which shows the brazing junction part of the fin and side support material in the heat exchanger using the side support material which concerns on this invention.

Hereinafter, specific embodiments of the present invention will be described.
FIG. 1 is a perspective view showing an embodiment of a heat exchanger using a side support material according to the present invention, and FIG. 2 is a front view of the heat exchanger shown in FIG.
A heat exchanger 1 shown in FIGS. 1 and 2 includes a pair of header pipes 2 and 2 that are spaced apart on the left and right sides, and parallel to each other in a direction perpendicular to the header pipe 2 between the header pipes 2 and 2. A plurality of tubes 3 made of aluminum alloy provided at intervals, corrugated fins 4 made of aluminum alloy provided so as to be installed between the adjacent tubes 3, 3, and a plurality of tubes 3 It is comprised from the side support material 5 and 5 which concerns on this invention provided in the upper and lower sides on the outer side.

In the heat exchanger 1, the header pipe 2, the tube 3, and the side support material 5 are inserted into the slots (insertion holes) formed in a plurality on the side surface of the header pipe 2, and the end portions of the tubes 3 and the header pipes 5 are inserted. Both are brazed to each other using a brazing material disposed around the insertion portion, and the tube 3, the side support material 5 and the fin 4 are brazed to each other.
In the heat exchanger 1 having such a configuration, the internal space (refrigerant passage) of each header pipe 2 and each tube 3 circulates the refrigerant, so that heat exchange between the refrigerant and the outside air is performed via the fins 4. It has become.

The shape of the header pipe 2 made of aluminum alloy is not particularly limited as long as it has a space through which the refrigerant passes. The header pipe 2 is not limited to the cylindrical shape shown in FIG. 2 and may have any shape.
The shape of the tube 3 is not particularly limited as long as the refrigerant is circulated through the internal space of the header pipe 2 and heat can be efficiently exchanged through the fins 4.
For example, an extruded multi-hole tube having a flat cross section and a plurality of flow holes formed therein, or an aluminum alloy in which a brazing material and a sacrificial material are bonded to one or both sides of a core material (rolled plate) A made brazing sheet can be used. What is necessary is just to form the thickness of the tube 3 in about 0.15-0.30 mm, for example.

The fin 4 is brazed to the tube 3 and the side support material 5 via the brazing material by being brazed in a state where the fin 4 is assembled to the tube 3 and the side support material 5. The shape of the fin 4 is not specifically limited, For example, it can select suitably according to the form of the heat exchanger 1 to which the fin 4 is applied, such as flat plate shape, corrugated plate shape, bellows shape. The plate | board thickness of the fin 4 shall be the range of 0.040-0.080mm, for example.
In the present invention, the fin 4 is made of an aluminum alloy such as JIS3003.

<Side support material>
FIG. 3 is a schematic diagram showing a brazed joint between the fin 4 and the side support material 5 in the heat exchanger 1 using the side support material according to the present invention. As shown in FIG. 3, the side support material 5 is formed by cladding a brazing material 5R on one surface of a core material 5S and cladding a diffusion preventing layer 5K on the other surface of the core material 5S. The side support material 5 has a brazing material 5R side surface brazed to the bent portion of the fin 4 and a fillet 7 is formed at the joint portion. The side support material 5 is plate-shaped and has a thickness of 0.8 to 2.0 mm.

The core material 5S of the side support material 5 has Mn: 1.0 to 2.0 mass%, Si: 0.5 to 1.5 mass%, Cu: 0.3 to 1.2 mass%, Mg: 0.03. It is comprised from about 0.3 mass% aluminum alloy which consists of remainder Al and an unavoidable impurity. The brazing material 5R clad on one surface of the core material 5S is made of an aluminum alloy composed of Si: 3.0 to 9.0% by mass, the balance Al and inevitable impurities. Further, the diffusion preventing layer 5K clad on the other surface of the core material 5S has Mn: 1.0 to 2.0 mass%, Si: 0.3 to 1.7 mass%, Cu: 0.03 to 0 .25% by mass, composed of an aluminum alloy composed of the balance Al and inevitable impurities.
Hereinafter, the reasons for limiting the composition of the aluminum alloy used in the present invention will be described.
In addition, content of each element described in this specification is mass% unless otherwise specified, and includes an upper limit and a lower limit unless otherwise specified. For example, the notation of 1.0 to 2.0% means 1.0% or more and 2.0% or less.

(Side support core composition)
“Mn: 1.0 to 2.0% by mass”
By setting the Mn content to 1.0% by mass or more, the strength after brazing when brazed to the fin can be improved by dispersion strengthening with the Al—Mn compound. When the Mn content is less than 1.0% by mass, the dispersion strengthening by the Al—Mn compound is small, and when brazing to the fin, the desired strength after brazing may not be obtained.
By setting the content of Mn to 2.0% by mass or less, it is possible to suppress an increase in Al- (Mn, Fe) -based coarse crystallized product during casting. When the Mn content exceeds 2.0% by mass, the Al- (Mn, Fe) -based coarse crystallized product increases during casting, and when brazed to the fin, the desired post-brazing strength is obtained. May not be obtained. Moreover, there exists a possibility that manufacturability (moldability) may fall.

[Si: 0.5 to 1.5% by mass]
By making the Si content 0.5% by mass or more and 1.5% by mass or less, the strength after brazing when brazed to the fin can be improved by dispersion strengthening with the Al—Mn—Si based compound. it can. When the Si content is less than 0.5% by mass, the dispersion strengthening by the Al—Mn—Si-based compound is small, and when brazing to the fin, the desired strength after brazing may not be obtained. On the other hand, when the Si content exceeds 1.5% by mass, the dispersion strengthening by the Al—Mn—Si based compound becomes too large, and the molding process may be difficult.

[Cu: 0.3 to 1.2% by mass]
By setting the Cu content to 0.3 mass% or more and 1.2 mass% or less, the strength after brazing can be improved by solid solution of Cu. When the content of Cu is less than 0.3% by mass, the amount of solid solution of Cu is small, and when brazing to a fin, the desired strength after brazing may not be obtained. Moreover, when the solid solution amount of Cu exceeds 1.2% by mass, the solid solution amount of Cu is large, the strength becomes too high, and the molding process may be difficult.

[Mg: 0.03-0.3 mass%]
By setting the Mg content to 0.03% by mass or more, the strength after brazing when brazed to the fin can be improved by dispersion strengthening and solid solution strengthening with an intermetallic compound. When the Mg content is less than 0.03% by mass, the influence of dispersion strengthening and solid solution strengthening due to the intermetallic compound is small, and the contribution to the strength after brazing when brazed to the fins may be small.
By making Mg content 0.3 mass% or less, it can suppress that the crystallization thing at the time of casting coarsens. When the content of Mg exceeds 0.3% by mass, the crystallized product at the time of casting becomes coarse, and the manufacturability (formability) may be reduced.

In the present invention, the core material 5S of the side support material 5 may contain one or two of Zr 0.05 to 0.25% by mass and Ti 0.03 to 0.20% by mass in addition to the above elements. it can.
These elements have the effect of increasing the strength of the core material 5S. When the content of these elements is less than the above range, the influence of dispersion strengthening and solid solution strengthening by the intermetallic compound is small, and the contribution to the strength after brazing is small. Moreover, when content of these elements exceeds the said range, the crystallization thing at the time of casting may coarsen, and there exists a possibility that manufacturability (productivity) may fall.

(Composition of side support brazing material)
[Si: 3.0 to 9.0% by mass]
When the Si content is 3.0% by mass or more and 9.0% by mass or less, sufficient brazability is obtained. When the content of Si is less than 3.0% by mass, the amount of molten brazing is small at the time of brazing heat treatment to the fin, and sufficient brazing property may not be obtained. Further, when the Si content exceeds 9.0 mass%, the amount of molten brazing is large during the brazing heat treatment to the fin, and there is a risk that significant brazing erosion to the fin 4 is likely to occur.

  In the present invention, it is preferable that the average equivalent circle diameter of the Si particles in the brazing material 5R of the side support material 5 is 2 μm or less. By setting the average equivalent circle diameter of the Si particles in the brazing material 5R to 2 μm or less, when the side support material 5 is brazed to the fins 4, the brazing erosion to the fins 4 can be more effectively suppressed. When the average equivalent circle diameter of the Si particles in the brazing material 5R exceeds 2 μm, coarse Si particles melt during the brazing heat treatment, and when the side support material 5 is brazed to the fins 4, the fins 4 undergo significant brazing corrosion. There is a risk of receiving.

(Composition of side support material diffusion prevention layer)
The diffusion preventing layer 5K is provided in order to prevent the brazing properties of the header pipe 2 and the side support 5 from being inhibited by Mg contained in the core material 5S. By providing the diffusion preventing layer 5K, Mg from the core material 5S can be prevented from diffusing during brazing, and the header pipe 2 and the side support 5 can be brazed firmly.
[Mn: 1.0 to 2.0% by mass]
By setting the Mn content to 1.0% by mass or more, the strength after brazing can be improved by dispersion strengthening with an Al—Mn compound. When the Mn content is less than 1.0% by mass, the dispersion strengthening by the Al—Mn compound is small, and the desired strength after brazing may not be obtained.
When the Mn content is 2.0% by mass or less, it is possible to suppress an increase in Al- (Mn, Fe) -based coarse crystallized product during casting. When the Mn content exceeds 2.0% by mass, the Al- (Mn, Fe) -based coarse crystallized product increases, and the desired strength after brazing may not be obtained. Moreover, there exists a possibility that manufacturability (moldability) may fall.

[Si: 0.3 to 1.7% by mass]
By setting the Si content to be 0.3% by mass or more and 1.7% by mass or less, the strength after brazing can be improved by dispersion strengthening with an Al—Mn—Si compound. When the Si content is less than 0.3% by mass, the dispersion strengthening due to the Al—Mn—Si compound is small, and the desired strength after brazing may not be obtained. On the other hand, when the Si content exceeds 1.7% by mass, the dispersion strengthening by the Al—Mn—Si based compound becomes too large, which may make the molding process difficult.

[Cu: 0.03-0.25 mass%]
By setting the Cu content to 0.03% by mass or more and 0.25% by mass or less, the strength after brazing can be improved by solid solution of Cu. When the Cu content is less than 0.03% by mass, the Cu solid solution amount is small, and the desired strength after brazing may not be obtained. Moreover, when content of Cu exceeds 0.25 mass%, there is much solid solution amount of Cu, raw material intensity | strength becomes high too much and there exists a possibility that a shaping | molding process may become difficult. In addition, since the potential becomes noble and the potential difference from the core material becomes small, a sufficient sacrificial anode effect does not work.

In the present invention, the diffusion preventing layer 5K of the side support material 5 can contain 0.05% by mass or more and less than 0.5% by mass of Zn in addition to the above elements.
When the Zn content is less than 0.05% by mass, the potential becomes noble and the potential difference from the core material 5S becomes small, so that the sufficient sacrificial anode effect may not work. Further, when the Zn content is 0.5% by mass or more, the potential becomes low, and the self-corrosion resistance of the side support material 5 alone may be reduced.

The overall thickness of the plate-like side support material 5 is preferably in the range of 0.8 to 2.0 mm, and the clad rate of the brazing material 5R of the side support material 5 is preferably in the range of 3 to 10%.
By setting the clad rate of the brazing material 5R of the side support material 5 in the range of 3 to 10%, sufficient brazing properties with the fins 4 can be obtained. When the clad rate of the brazing material 5R is less than 3%, the amount of the molten brazing is small during the brazing heat treatment, and there is a possibility that sufficient brazing properties cannot be obtained. Further, when the cladding ratio of the brazing material 5R exceeds 10%, the amount of the molten brazing is excessively increased during the brazing heat treatment, and the fin 4 may be subjected to significant brazing erosion.

Moreover, it is preferable that the clad rate of the diffusion preventing layer 5K of the side support material 5 is in the range of 3 to 10%.
By setting the cladding rate of the diffusion preventing layer 5K of the side support material 5 in the range of 3 to 10%, a sufficient sacrificial anode effect can be obtained. When the cladding rate of the diffusion preventing layer 5K is less than 3%, the diffusion preventing layer 5K becomes thin, and there is a possibility that a sufficient sacrificial anode effect cannot be obtained. Moreover, when the cladding rate of the diffusion preventing layer 5K exceeds 10%, the core material 5S becomes thin, and the desired strength after brazing may not be obtained.

In the present invention, the crystal grain size after brazing of the core material 5S of the side support material 5 is preferably 200 μm or less. By setting the crystal grain size after brazing of the core material 5S to 200 μm or less, brazing erosion of the side support 5 to the core material 5S during brazing is promoted, and brazing erosion to the fins 4 is more effectively performed. Can be suppressed.
When the crystal grain size of the core material 5S exceeds 200 μm, the brazing erosion of the side support 5 to the core material 5S during the brazing heat treatment becomes small, and the fins 4 may be significantly brazed by excessive melting brazing.

(Manufacturing method of side support material)
The side support material 5 is formed by casting an aluminum alloy for a core material, an aluminum alloy for a diffusion preventing layer, and an aluminum alloy for a brazing material, and subjecting the obtained ingot to a homogenization treatment or a homogenization treatment. After forming an aluminum alloy plate by hot rolling, annealing is performed, and then a thin aluminum alloy plate having a thickness slightly thicker than the target plate thickness is obtained by cold rolling, and then intermediate annealing is performed to obtain the target plate thickness. Thus, it can manufacture by giving cold rolling.
In the manufacturing process of the side support material 5, when performing a homogenization process, it is preferable to carry out in a high temperature range. Specifically, it is preferable to perform the homogenization treatment on the core material 5S of the side support material 5 under the conditions of a treatment temperature of 550 ° C. or more and 610 ° C. or less and a treatment time of 1 hour or more and 10 hours or less. By homogenizing under such conditions, the crystal grain size of the core material 5S of the side support material 5 can be made fine, and the brazing erosion to the core material 5S is increased during the brazing heat treatment, and the brazing to the fins 4 is performed. Erosion can be suppressed.

When the treatment temperature of the homogenization treatment is less than 550 ° C. or the treatment time is less than 1 hour, the crystal grain size after brazing of the core material 5S becomes coarse, and the brazing heat treatment of the side support material 5 to the core material 5S is performed. There is a risk that the erosion is reduced and the fins 4 are subject to significant wax erosion due to excessive melting wax. In addition, when the treatment temperature of the homogenization treatment exceeds 610 ° C. or the treatment time exceeds 10 hours, the intermetallic compound becomes coarse and the desired strength after brazing cannot be obtained, and the self-corrosion resistance may be lowered. .
In addition, this homogenization process is performed as needed, and it is preferable not to perform the homogenization process itself, rather than performing the homogenization process outside the temperature range and the time range described above.

  As shown in FIGS. 1 and 2, the heat exchanger 1 using the side support material 5 of the present embodiment is arranged with the header pipe 2, the side support material 5, the tubes 3, and the fins 4, and then the bent portions of the fins 4 are tubed. By brazing and fixing the upper surface or the lower surface of 3 and the surface of the side support material 5 on the brazing material 5R side, the end of the tube 3 and the end of the side support material 5 and the header pipe 2 are fixed by brazing. Manufactured.

In the side support material 5 of the present embodiment, a brazing material 5R containing Si with a predetermined content is clad on one surface of a core material 5S containing Mn, Si, Cu, Mg with a predetermined content, and the other side. Since the diffusion prevention layer 5K containing Mn, Si, and Cu with a predetermined content is clad on the surface of the surface, when the fin 4 is brazed, there is little brazing of the fin 4 and erosion resistance Excellent.
Therefore, in the heat exchanger 1 using the side support material 5 of the present embodiment, the brazing erosion rate of the joint area of the fin 4 after the side support material 5 is brazed to the fin 4 can be 50% or less.
Here, the wax erosion rate in the joint area of the fin 4 is the ratio of the wax erosion on the fin 4 side when the cross section of the joint between the fin 4 and the side support material 5 is observed. The original area of the fin 4 is calculated as a denominator, and the area of the brazed erosion portion of the fin 4 after brazing is calculated as a numerator. That is, (wax erosion rate of the joint area of the fin 4) = (cross-sectional area of the braze erosion part of the fin 4 at the joint after brazing) / (cross-sectional area of the joint of the fin 4 before brazing) × 100 (%).

  In addition, the heat exchanger 1 using the side support material 5 of the present embodiment is suppressed in brazing of the fins 4 and has excellent erosion resistance, excellent moldability, and excellent post-brazing strength. . For this reason, the fin 4 and the tube 3 and the side support material 5 are reliably joined, and heat exchange between the refrigerant and the outside air is efficiently performed through the fin 4. Moreover, since the side support material 5 of this invention has the intensity | strength excellent after brazing to the fin 4, it is suitable as a side support material for the heat exchanger 1 provided with the intensity | strength which was excellent even if it reduced in weight and size.

  As mentioned above, although each embodiment of the heat exchanger which concerns on this invention was described, each part which comprises the heat exchanger 1 using the above-mentioned side support material 5 is an example, Comprising: suitably in the range which does not deviate from the scope of the present invention Can be changed.

  Examples of the present invention will be described below, but the present invention is not limited to these examples.

(Examples 1-31 and Comparative Examples 1-16)
"Production of side support materials"
Each element was contained in the contents shown in Table 1 and Table 2, and the balance aluminum alloy for the core material, the aluminum alloy for the diffusion prevention layer, and the aluminum alloy for the brazing material were cast by semi-continuous casting. . Next, the obtained ingot was homogenized under the conditions shown in Tables 1 and 2.
Subsequently, the ingot for diffusion prevention layer was combined with one side of the ingot of the obtained core material, and the ingot for brazing material was further combined with the other side to form a clad material. After a predetermined thickness was obtained by hot rolling, annealing was performed, and then a thin aluminum alloy plate having a thickness slightly larger than the target thickness was obtained by cold rolling. Thereafter, the obtained aluminum alloy plate was subjected to intermediate annealing, and by final cold rolling, a brazing material was clad on one surface of the core material, and a diffusion prevention layer was clad on the other surface, thickness 1.0 mm The side support material of H14 refining was obtained. The clad rate of the brazing material of the obtained side support material was 5%, and the clad rate of the diffusion prevention layer was 5%.

"Evaluation"
The produced side support material was evaluated as follows. The evaluation results are shown in Tables 1 and 2.
1. Formability of side support material The obtained side support material is formed into a U-shaped cross section with a length of 450mm x width 18mm by press molding (the length of each U-shaped piece is 18mm), and the side support material after molding The dimensions of were measured. When the dimensional difference of ± 5 to 10% occurs with respect to the dimension after molding of the side support material of Example 1 shown in Table 1, “△”, and when the dimensional difference of more than ± 10% occurs, “×” ".

2. The average equivalent circle diameter of the Si particles in the brazing material of the side support material The cross section of the side support material was observed using a scanning electron microscope JSM-6390LV (manufactured by JEOL Ltd.), and image analysis software Image for the Si particles in the brazing material -Pro (Media Cybernetics) was used for image analysis, and the average equivalent circle diameter was measured.

3. Tensile strength immediately after brazing of side support material Corrugated forming process, corrugated thickness 0.05mm, JIS3003 alloy fin is assembled on the side support material brazing material side surface, 600 ℃ in nitrogen atmosphere The side support material and the fins were brazed by brazing for 3 minutes. The strength of the side support material was measured by performing a tensile test immediately after brazing. The side support material is processed into the shape of a JIS No. 5 test piece, and this is used as a test piece. By using AG-GI 10kN as a tensile tester, a tensile test is performed at a tensile speed of 2 mm / min. The tensile strength (yield strength: MPa) immediately after brazing was measured. The tensile strength is 170 MPa or more and the strength is good.

4). Tensile strength after aging of side support material The side support material brazed with the fins according to the above procedure was subjected to aging treatment at 80 ° C. for 1 week, and then subjected to a tensile test in the same manner as described above.

5. Crystal grain size of the core material of the side support material after brazing Using a metal microscope BX60M (manufactured by Olympus Corporation), the side support material is observed from a cross section parallel to the rolling direction, and the crystal grains are clarified by etching. The crystal grain size was measured.

6). Fillet size of the joint between the fin and the side support material After assembling and brazing the side support material and the corrugated fin in the above procedure, using the metal microscope BX60M (manufactured by Olympus Corporation), the brazed joint between the side support and the fin The fillet formed in the cross section was observed from the cross section, a cross-section photograph of the fillet was taken, and the fillet size was determined from the photograph. When a dimensional difference of more than ± 10% occurred with respect to the fillet size of Example 1 shown in Table 1, it was evaluated as “x”.

7). Wax erosion After the side support and corrugated thickness 0.05mm, JIS3003 alloy fin is assembled and brazed by the above procedure, the metal support microscope BX60M (Olympus Co., Ltd.) is used to braze the side support material and the fin. The fillet formed at the joint was observed from the cross section, a cross-section photograph of the fillet was taken, and the brazing erosion property was judged from the brazing erosion rate.

  As shown in Table 1, each of Examples 1 to 31 is excellent in strength after brazing of the side support material, has good moldability, suppresses brazing of the fins, and is excellent in erosion resistance. It was. Especially, in Examples 1-23 which performed homogenization processing in the range of 550-610 degreeC and 1 to 10 hours, and Examples 27-29 which did not perform homogenization processing, the moldability of a side support material is good. In addition, the erosion resistance was particularly excellent.

As shown in Table 2, Comparative Examples 1, 3, 5, and 7 in which the content of any of Mn, Si, Cu, and Mg in the core material of the side support material is lower than the predetermined range of the present invention are those after brazing. The strength was reduced. Further, in Comparative Examples 1 and 3 having a low Mn or Si content, the erosion resistance was low.
In Comparative Examples 2, 4, 6, and 8 in which the content of any of Mn, Si, Cu, and Mg in the core material of the side support material exceeds the predetermined range of the present invention, the strength of the core material becomes too high, and molding is performed. The nature was low.

In Comparative Example 9 in which the content of Si in the brazing material of the side support material is less than the predetermined range of the present invention, the amount of molten brazing during brazing heat treatment is reduced, the fillet size is small, and sufficient brazing properties are obtained. There wasn't.
In Comparative Example 10 in which the content of Si in the brazing filler metal of the side support material was larger than the predetermined range of the present invention, the amount of brazing filler metal was too large, so the brazing erosion rate was high and the fillet size was large.

In Comparative Examples 11, 13, and 15 in which the content of any of Mn, Si, and Cu in the diffusion preventing layer of the side support material is lower than the predetermined range of the present invention, the strength after brazing was lowered.
In Comparative Examples 12, 14, and 16, in which the content of any of Mn, Si, and Cu in the diffusion preventing layer of the side support material exceeds the predetermined range of the present invention, the strength of the diffusion preventing layer becomes too high, and the moldability is increased. It was low.

  DESCRIPTION OF SYMBOLS 1 ... Heat exchanger, 2 ... Header pipe, 3 ... Tube, 4 ... Fin, 5 ... Side support material, 5S ... Core material, 5K ... Diffusion prevention layer, 5R ... Brazing material, 7 ... Fillet.

Claims (6)

  Mn: 1.0-2.0% by mass, Si: 0.5-1.5% by mass, Cu: 0.3-1.2% by mass, Mg: 0.03-0.3% by mass, balance Al On one surface of a core material composed of an aluminum alloy composed of unavoidable impurities, a brazing material composed of an aluminum alloy composed of Si: 3.0 to 9.0% by mass, the balance Al and unavoidable impurities is clad, From the other surface of the core material, Mn: 1.0 to 2.0% by mass, Si: 0.3 to 1.7% by mass, Cu: 0.03 to 0.25% by mass, balance Al and inevitable impurities A side support material comprising a diffusion barrier layer made of an aluminum alloy.   The said core material further contains 1 type or 2 types in Zr: 0.05-0.25 mass% and Ti: 0.03-0.20 mass%, The claim 1 characterized by the above-mentioned. Side support material as described.   The side support material according to claim 1 or 2, wherein the diffusion preventing layer further contains Zn: 0.05 mass% or more and less than 0.5 mass%.   The side support material according to any one of claims 1 to 3, wherein a crystal grain size of the core material after brazing is 200 µm or less.   The side support material according to any one of claims 1 to 4, wherein an average equivalent-circle diameter of Si particles in the brazing material is 2 µm or less. A method for producing the side support material according to any one of claims 1 to 5,
The core material of the side support is manufactured by a manufacturing method in which homogenization is performed at 550 ° C. or more and 610 ° C. or less and 1 hour or more and 10 hours or less, or a manufacturing method in which the homogenization processing is not performed. Production method.

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