JP7328194B2 - aluminum alloy brazing sheet - Google Patents

Description

TECHNICAL FIELD The present invention relates to an aluminum alloy brazing sheet, and more particularly to an aluminum alloy brazing sheet used for automotive heat exchangers and the like.

Automobile heat exchangers are usually manufactured by forming, assembling, and brazing aluminum alloy plates that are lightweight and have excellent thermal conductivity. A brazing sheet composed of a core material, a brazing material, and a sacrificial material is used as the plate material in order to achieve strength, brazeability, and corrosion resistance. Al--Mn alloys, which have relatively high strength, are mainly used for the core material, and alloying elements such as Mg, Cu, and Si are added to the core material in order to improve the strength.

However, when even a small amount of Mg such as 0.1% by mass is added to the core material, there is a problem that Mg diffuses into the brazing filler metal due to heating during brazing, reacts with the flux, and significantly deteriorates brazability.
Therefore, as a method for improving the brazeability of a brazing sheet in which Mg is added to the core material, for example, in Patent Document 1, a Mg diffusion suppressing layer (intermediate layer) is provided between the core material and the brazing material to reduce the Mg content. A brazing sheet that suppresses diffusion and improves brazeability has been proposed.

JP-A-2006-131923

From the viewpoint of increasing the strength, the method of adding Mg to the core material is very effective. However, when the amount of Mg added to the core material increases, it becomes impossible to suppress the deterioration of brazeability even in the case of the structure provided with the intermediate layer shown in Patent Document 1, and as a result, strength and brazeability It is difficult to achieve both In particular, in the technique disclosed in Patent Document 1, the brazeability on the surface of the sacrificial material has not been sufficiently studied, and it is difficult to suppress the occurrence of brazing defects at the joint between the sacrificial material and the brazing material.

Accordingly, an object of the present invention is to provide an aluminum alloy brazing sheet that achieves both strength after brazing and brazeability.

In order to solve the above-described problems, the present inventors focused on each component of an aluminum alloy brazing sheet having a four-layer structure of sacrificial material-core material-intermediate layer-brazing material, and investigated the effects of each component on the above-described problems. I studied hard.
As a result, it was found that by limiting the content of Mn in the sacrificial material to a predetermined value or less, the brazeability can be improved even if the core material contains a large amount of Mg in order to improve strength. Specifically, by reducing the Mn content of the sacrificial material, the fluidity of the molten brazing material on the surface of the sacrificial material during brazing is greatly improved, and as a result, the strength after brazing based on Mg in the core material is improved. It was found that the brazeability can be improved while enjoying the effect of.

That is, the aluminum alloy brazing sheet according to the present invention comprises a core material, a sacrificial material provided on one side of the core material, a brazing material provided on the other side of the core material, and the core material and the brazing material. and an intermediate layer provided therebetween, wherein the core material contains Si: 0.30% by mass or more and 1.00% by mass or less, and Mn: 0.50% by mass or more and 2.00% by mass. % or less, Cu: 0.60% by mass or more and 1.20% by mass or less, Mg: 0.05% by mass or more and 0.80% by mass or less, the balance being Al and unavoidable impurities, and the sacrificial material is Si: 0.10% by mass or more and 1.20% by mass or less, Zn: 2.00% by mass or more and 7.00% by mass or less, Mn: 0.40% by mass or less, the balance being Al and unavoidable impurities, the intermediate layer is Si: 0.05% by mass or more and 1.20% by mass or less, Mn: 0.50% by mass or more and 2.00% by mass or less, Cu: 0.10% by mass or more and 1.20% by mass or less, and the balance being Al and unavoidable impurities.

The aluminum alloy brazing sheet according to the present invention can exhibit excellent post-brazing strength and brazeability.

1 is a cross-sectional view of an aluminum alloy brazing sheet according to an embodiment of the present invention; FIG. FIG. 4 is a diagram for explaining a gap filling test, and is a perspective view of a state in which the lower plate and the upper plate are combined. FIG. 4 is a diagram for explaining a gap filling test, and is a side view of a state in which the lower plate and the upper plate are combined; FIG. 4 is a diagram for explaining a wax spread test, and is a top view of a state in which an upper plate is placed on a lower plate; In addition, it is a figure of the state which removed the upper stainless steel plate. FIG. 4 is a diagram for explaining a wax spread test, and is a side view of a state in which an upper plate is placed on a lower plate;

EMBODIMENT OF THE INVENTION Hereinafter, with reference to drawings suitably, the form for implementing the aluminum alloy brazing sheet (henceforth a brazing sheet suitably) which concerns on this invention is demonstrated.

[Aluminum alloy brazing sheet]
As shown in FIG. 1, the brazing sheet according to this embodiment includes a core material 1, a sacrificial material 2 provided on one side of the core material 1, a brazing material 4 provided on the other side of the core material 1, and a core material 1 and an intermediate layer 3 provided between the brazing material 4. That is, the brazing sheet 10 according to this embodiment has a four-layer structure.
In the brazing sheet 10 according to this embodiment, the content of each component of the core material 1, the sacrificial material 2, and the intermediate layer 3 is appropriately specified.
Hereinafter, the reasons for numerically limiting each component of the core material, sacrificial material, and intermediate layer of the brazing sheet according to this embodiment will be described in detail.

[Heartwood]
The core material of the brazing sheet according to this embodiment contains Si, Mn, Cu, and Mg, and the balance is Al and unavoidable impurities.
Moreover, the core material of the brazing sheet according to the present embodiment may further contain one or more of Ti, Cr, and Zr.

(Si in core material: 0.30% by mass or more and 1.00% by mass or less)
Si improves the strength after brazing by forming a solid solution in the base material and forming an Al--Mn--Si intermetallic compound together with Mn. In addition, Si improves strength after brazing together with Mg. If the Si content is less than 0.30% by mass, the strength improvement effect is small. On the other hand, if the Si content exceeds 1.00% by mass, the solidus temperature is lowered, which may cause melting during brazing.
Therefore, the content of Si is 0.30% by mass or more and 1.00% by mass or less.

From the viewpoint of improving the strength after brazing, the Si content is preferably 0.40% by mass or more, more preferably 0.50% by mass or more. From the viewpoint of avoiding melting during brazing, the Si content is preferably 0.80% by mass or less, more preferably 0.70% by mass or less.

(Mn of core material: 0.50% by mass or more and 2.00% by mass or less)
Mn improves the strength after brazing by forming a solid solution in the base material and forming an Al--Mn--Si intermetallic compound together with Si. If the Mn content is less than 0.50% by mass, the strength improvement effect is small. On the other hand, if the Mn content exceeds 2.00% by mass, the intermetallic compound precipitates coarsely, degrading the rollability and making it difficult to produce a brazing sheet.
Therefore, the content of Mn is 0.50% by mass or more and 2.00% by mass or less.

From the viewpoint of improving the strength after brazing, the Mn content is preferably 0.80% by mass or more, more preferably 1.20% by mass or more. Moreover, the Mn content is preferably 1.80% by mass or less, more preferably 1.60% by mass or less, from the viewpoint of suppressing deterioration of the rollability.

(Cu in core material: 0.60% by mass or more and 1.20% by mass or less)
Cu dissolves in the matrix after brazing and improves the strength after brazing. If the Cu content is less than 0.60% by mass, the strength improvement effect is small. On the other hand, if the Cu content exceeds 1.20% by mass, the solidus temperature decreases, and there is a risk of melting during brazing.
Therefore, the content of Cu is 0.60% by mass or more and 1.20% by mass or less.

From the viewpoint of improving the strength after brazing, the Cu content is preferably 0.80% by mass or more, more preferably 0.90% by mass or more. Moreover, the Cu content is preferably 1.10% by mass or less from the viewpoint of avoiding melting during brazing.

(Mg in core material: 0.05% by mass or more and 0.80% by mass or less)
Mg improves post-brazing strength through interaction with Si. If the Mg content is less than 0.05% by mass, the strength improvement effect is small. On the other hand, when the content of Mg exceeds 0.80% by mass, it reacts with the flux used for brazing, resulting in a marked deterioration in brazeability.
Therefore, the content of Mg is 0.05% by mass or more and 0.80% by mass or less.

From the viewpoint of improving the strength after brazing, the Mg content is preferably 0.30% by mass or more, more preferably 0.40% by mass or more. Moreover, the content of Mg is preferably 0.70% by mass or less from the viewpoint of avoiding deterioration of brazeability.

(Ti of core material: 0.30% by mass or less)
As is generally known, Ti is distributed in layers in an aluminum alloy, so that the electric potential distribution of the brazing sheet also becomes a distribution corresponding to the concentration of Ti. Since it is possible to reduce the rate of progress of corrosion in the direction, it contributes to the improvement of corrosion resistance. However, if the Ti content exceeds 0.30% by mass, coarse Al ₃ Ti intermetallic compounds are likely to be formed during casting, and workability is reduced, so cracks are likely to occur during tube molding.
Therefore, when Ti is contained, the content of Ti is 0.30% by mass or less.

(Cr in core material: 0.30% by mass or less)
As is generally known, Cr improves strength after brazing by forming Al ₃ Cr dispersed particles with Al for dispersion strengthening. However, when the Cr content exceeds 0.30% by mass, a coarse Al ₃ Cr intermetallic compound is formed, degrading the rollability.
Therefore, when Cr is contained, the content of Cr is 0.30% by mass or less.

(Zr in core material: 0.30% by mass or less)
As is generally known, Zr improves strength after brazing by forming Al ₃ Zr dispersed particles with Al for dispersion strengthening. However, if the Zr content exceeds 0.30% by mass, a coarse Al ₃ Zr intermetallic compound is formed, and workability is lowered, so that cracks are likely to occur during tube molding.
Therefore, when Zr is contained, the content of Zr is 0.30% by mass or less.

If the above-described Ti, Cr, and Zr do not exceed the above-described upper limits, the core material naturally contains one or more types, that is, not only when one type is included, but also when two or more types are included. do not interfere with the effect.

(Remainder of core material: Al and unavoidable impurities)
The remainder of the core material of the brazing sheet according to this embodiment is Al and unavoidable impurities. The unavoidable impurities are impurities that are unavoidably mixed when the raw material is melted. may be contained.
Specifically, V, Ni, Ca, Na, Sr, Li, Mo, Zn, Sn, and In each do not inhibit the effects of the present invention as long as they are in the range of 0.05% by mass or less. And, if each of these components does not exceed the predetermined content described above, the effect of the present invention is hindered not only when it is contained as an unavoidable impurity but also when it is actively added. do not have.
In addition, Ti, Cr, and Zr described above may also be contained as unavoidable impurities, and the content in this case is, for example, 0.1% by mass or less individually and 0.3% by mass or less in total.

[Sacrificial material]
The sacrificial material of the brazing sheet according to this embodiment contains Si, Zn, and Mn, and the balance is Al and unavoidable impurities.
Moreover, the sacrificial material of the brazing sheet according to this embodiment may further contain one or more of Ti, Cr, and Zr.

(Si of sacrificial material: 0.10% by mass or more and 1.20% by mass or less)
Si improves the strength of the sacrificial material. If the Si content is less than 0.10% by mass, the strength improvement effect is small. On the other hand, if the Si content exceeds 1.20% by mass, the solidus temperature is lowered, which may cause melting during brazing.
Therefore, the content of Si is 0.10% by mass or more and 1.20% by mass or less.

From the viewpoint of improving the strength, the Si content is preferably 0.30% by mass or more, more preferably 0.40% by mass or more, and more preferably 0.60% by mass or more. From the viewpoint of avoiding melting during brazing, the Si content is preferably 1.00% by mass or less, more preferably 0.90% by mass or less.

(Zn in sacrificial material: 2.00% by mass or more and 7.00% by mass or less)
Zn prevents pitting corrosion and crevice corrosion by making the potential of the base material base and enhancing the sacrificial corrosion protection effect on the core material and the intermediate layer. If the Zn content is less than 2.00% by mass, the effect of sacrificial corrosion protection is small. On the other hand, if the Zn content exceeds 7.00% by mass, the self-corrosiveness of the sacrificial material increases excessively, and the corrosion resistance of the entire brazing sheet is lowered.
Therefore, the Zn content is 2.00% by mass or more and 7.00% by mass or less.

The Zn content is preferably 3.00% by mass or more, more preferably 4.00% by mass or more, from the viewpoint of enhancing the sacrificial anticorrosion effect. Moreover, from the viewpoint of avoiding a decrease in corrosion resistance, the Zn content is preferably 6.00% by mass or less, more preferably 5.00% by mass or less.

(Mn of sacrificial material: 0.40% by mass or less)
Mn improves the strength after brazing by forming a solid solution in the base material and forming an Al--Mn--Si intermetallic compound together with Si. It also has a great influence on the fluidity of the molten brazing material on the surface of the sacrificial material. Specifically, when the Mn content is 0.40% by mass or less, the fluidity of the molten brazing filler metal on the surface of the sacrificial material is significantly increased during brazing, and the brazeability can be greatly improved.
Therefore, the content of Mn is 0.40% by mass or less.

From the viewpoint of improving brazeability, the Mn content is preferably 0.30% by mass or less, 0.20% by mass or less, 0.10% by mass or less, 0.03% by mass or less, and 0.01% by mass. The following are more preferred.
On the other hand, the lower limit of the Mn content is not particularly limited, and may be 0% by mass.

In addition, since the content of Mn in the sacrificial material of the brazing sheet according to the present embodiment is regulated to a predetermined value or less, although the strength of the sacrificial material itself is slightly reduced, Mg in the core material and Si , Mn, and Cu, respectively, the strength of the brazing sheet as a whole can be ensured.

(Ti, Cr, Zr of sacrificial material: 0.30% by mass or less)
Ti, Cr, and Zr in the sacrificial material behave similarly to Ti, Cr, and Zr in the core material, respectively. , 0.30% by mass or less.
If the above-mentioned Ti, Cr, and Zr do not exceed the above-described upper limits, the sacrificial material includes not only one type but also two or more types. It does not interfere with the effects of the present invention.

(Remainder of sacrificial material: Al and unavoidable impurities)
The remainder of the sacrificial material of the brazing sheet according to this embodiment is Al and unavoidable impurities. The unavoidable impurities are impurities that are unavoidably mixed when the raw material is melted. may be contained.
Specifically, V, Ni, Ca, Na, Sr, Li, Mo, Zn, Sn, and In each do not inhibit the effects of the present invention as long as they are in the range of 0.05% by mass or less. And, if each of these components does not exceed the predetermined content described above, the effect of the present invention is hindered not only when it is contained as an unavoidable impurity but also when it is actively added. do not have.
In addition, Mn, Ti, Cr, and Zr described above may also be contained as unavoidable impurities. be.

[Middle layer]
The intermediate layer of the brazing sheet according to this embodiment contains Si, Mn, and Cu, and the balance is Al and unavoidable impurities.
In addition, the intermediate layer of the brazing sheet according to this embodiment may contain Mg, and may further contain one or more of Ti, Cr, and Zr.

(Si in intermediate layer: 0.05% by mass or more and 1.20% by mass or less)
Si improves the strength after brazing by forming a solid solution in the base material or by forming an Al--Mn--Si intermetallic compound together with Mn. If the Si content is less than 0.05% by mass, the strength improvement effect is small. On the other hand, if the Si content exceeds 1.20% by mass, the solidus temperature is lowered, which may cause melting during brazing.
Therefore, the content of Si is 0.05% by mass or more and 1.20% by mass or less.

From the viewpoint of improving the strength after brazing, the Si content is preferably 0.30% by mass or more, more preferably 0.50% by mass or more, and more preferably 0.70% by mass or more. From the viewpoint of avoiding melting during brazing, the Si content is preferably 1.10% by mass or less, and preferably 1.00% by mass or less.

(Mn in intermediate layer: 0.50% by mass or more and 2.00% by mass or less)
Mn improves the strength after brazing by forming a solid solution in the base material and forming an Al--Mn--Si intermetallic compound together with Si. If the Mn content is less than 0.50% by mass, the strength improvement effect is small. On the other hand, if the Mn content exceeds 2.00% by mass, the intermetallic compound precipitates coarsely, degrading the rollability and making it difficult to produce a brazing sheet.
Therefore, the content of Mn is 0.50% by mass or more and 2.00% by mass or less.

From the viewpoint of improving the strength after brazing, the Mn content is preferably 0.80% by mass or more, more preferably 1.20% by mass or more. Moreover, the Mn content is preferably 1.80% by mass or less, more preferably 1.60% by mass or less, from the viewpoint of suppressing deterioration of the rollability.

(Cu in intermediate layer: 0.10% by mass or more and 1.20% by mass or less)
Cu dissolves in the matrix after brazing and improves the strength after brazing. If the Cu content is less than 0.10% by mass, the strength improvement effect is small. On the other hand, if the Cu content exceeds 1.20% by mass, the solidus temperature decreases, and there is a risk of melting during brazing.
Therefore, the content of Cu is 0.10% by mass or more and 1.20% by mass or less.

From the viewpoint of improving the strength after brazing, the Cu content is preferably 0.60% by mass or more, more preferably 0.80% by mass or more, and more preferably 0.90% by mass or more. From the viewpoint of avoiding melting during brazing, the Cu content is preferably 1.10% by mass or less, more preferably 1.00% by mass or less.

(Mg in intermediate layer: 0.20% by mass or less)
Mg improves post-brazing strength through interaction with Si. However, if the Mg content exceeds 0.20% by mass, the amount of Mg diffused from the intermediate layer to the brazing filler metal during brazing addition heat increases, and a large amount of reaction with the flux used for brazing occurs, significantly reduce sexuality.
Therefore, when containing Mg, the content of Mg is 0.20% by mass or less.

(Ti, Cr, Zr in intermediate layer: 0.30% by mass or less)
Ti, Cr, and Zr in the intermediate layer behave similarly to Ti, Cr, and Zr in the core material, respectively. , 0.30% by mass or less.
If the above-described Ti, Cr, and Zr do not exceed the above-described upper limits, the intermediate layer may naturally contain one or more types, that is, not only when one type is included, but also when two or more types are included. It does not interfere with the effects of the present invention.

(Remainder of intermediate layer: Al and unavoidable impurities)
The remainder of the intermediate layer of the brazing sheet according to this embodiment is Al and unavoidable impurities. The unavoidable impurities are impurities that are unavoidably mixed when the raw material is melted. may be contained.
Specifically, V, Ni, Ca, Na, Sr, Li, Mo, Zn, Sn, and In each do not inhibit the effects of the present invention as long as they are in the range of 0.05% by mass or less. And, if each of these components does not exceed the predetermined content described above, the effect of the present invention is hindered not only when it is contained as an unavoidable impurity but also when it is actively added. do not have.
In addition, the aforementioned Mg, Ti, Cr, and Zr may also be contained as unavoidable impurities. be.

[Brazing material]
The brazing material of the brazing sheet according to this embodiment is made of, for example, an Al—Si alloy. Examples of Al—Si alloys include general JIS alloys such as 4343 and 4045 defined in JIS Z3263:2002. As the Al—Si alloy, for example, one containing 5% by mass or more and 15% by mass or less (preferably 7% by mass or more and 13% by mass or less) of Si can be used. However, the Si content is not limited to this range. Further, the brazing material may have a known component composition capable of exhibiting its function as a brazing material, and may be an Al--Si--Zn alloy or the like. Also, it may contain other elements.

[Use]
The brazing sheet according to this embodiment can be used, for example, as a member of an automotive heat exchanger, such as a radiator tube material.

[Thickness and clad rate]
The thickness of the brazing sheet according to the present embodiment is not particularly limited. be.
In addition, the clad rate of each member of the brazing sheet according to the present embodiment (the ratio of the thickness of each member when the total thickness of the brazing sheet is 100%) is not particularly limited, but for example, the clad rate of the brazing material is 5% to 25% (preferably 10% to 20%), the cladding rate of the intermediate layer is 5% to 25% (preferably 7% to 20%), and the sacrificial material has a cladding rate of 5% or more. It is 25% or less (preferably 10% or more and 20% or less).

[Method for producing brazing sheet]
The method for manufacturing the brazing sheet according to the present embodiment is not particularly limited, and for example, the brazing sheet is manufactured by a known clad material manufacturing method. An example will be described below.
First, an aluminum alloy having the composition of core material, sacrificial material, brazing material, and intermediate layer is melted and cast, and if necessary, is chamfered (surface smoothing treatment of the ingot) and homogenized. Obtain each ingot. Then, the ingot of the sacrificial material, the brazing material, and the intermediate layer is subjected to hot rolling or mechanical slicing to a predetermined thickness, combined with the ingot of the core material, and hot-rolled into a clad material according to a conventional method. do. After that, the clad material is subjected to cold rolling, intermediate annealing if necessary, final cold rolling, and final annealing if necessary.
The homogenization treatment is preferably carried out at 400 to 610° C. for 1 to 20 hours, and the intermediate annealing is preferably carried out at 200 to 450° C. for 1 to 20 hours. Also, the final annealing is preferably carried out at 150-450° C. for 1-20 hours. Then, when performing the final annealing, it is possible to omit the intermediate annealing. Any of H1n, H2n, and H3n (JIS H0001:1998) may be used for refining.
The method for producing an aluminum alloy brazing sheet according to the present embodiment is as described above, but for conditions not specified in each of the steps, conventionally known conditions may be used. Needless to say, the conditions can be changed as appropriate as long as the effect obtained by is exhibited.

Next, the aluminum alloy brazing sheet according to the present invention will be specifically described by comparing Examples satisfying the requirements of the present invention and Comparative Examples not satisfying the requirements of the present invention.

[Production of test material]
By the above-described manufacturing method shown as this embodiment, an aluminum alloy having the composition shown in Tables 1 to 4 is cast, homogenized, and hot rolled (or sliced), and brazing material-intermediate layer-core material-sacrificial material. were superimposed, hot rolled, cold rolled, and finally annealed to produce a test material (brazing sheet) having a thickness of 0.2 mm.

[contents of the test]
(Strength test after brazing)
The prepared test material is cut into a size according to need, and after performing a heat treatment equivalent to brazing in a nitrogen atmosphere at a temperature range of 577 ° C or higher for 7 to 8 minutes, it is held at room temperature for 7 days. did. A JISZ2241:2011 No. 13B test piece was prepared from this test material, and the tensile strength was measured using a tensile tester. The crosshead speed was set at 5 mm/min until the 0.2% proof stress was reached, and then at 20 mm/min until the test piece broke.
As for the "strength after brazing", 190 MPa or more was judged to be acceptable.

(Brazability: gap filling test)
The prepared test material was cut into a size of 25 mm×55 mm to obtain a test piece. Then, after coating the surface of the brazing filler metal of the test piece (test material) with a fluoride-based flux, the test pieces are placed between the lower plate 21 and the upper plate 22 so as to achieve the states shown in FIGS. 2A and 2B. A stainless steel spacer 23 having a diameter of 2 mm was sandwiched, and fixed using a wire 24 with a certain clearance provided. Then, the test piece in this state was held in a temperature range of 577° C. or higher for 3 to 4 minutes in a nitrogen atmosphere, and then the gap filling length was measured. The maximum brazing temperature was set at the melting temperature of the test material or less.
The lower plate 21, which is the test piece in FIGS. 2A and 2B, is arranged so that the brazing material side faces upward. 2A and 2B, an aluminum alloy plate with alloy number 3003 defined in JISZ3263:2002 and having a thickness of 1 mm was used.
As for the "brazability of the brazing filler metal surface" indicated by the results of the gap filling test, 15 mm or more was judged to pass.

(Brazability: wax spreading test)
The prepared test material was cut into a size of 40 mm×70 mm to obtain a test piece. Then, using two stainless steel plates 33 and fixtures 34 (bolts and nuts), the lower plate 31 and the upper plate 32, which are test pieces (test materials), are held together so that the state shown in FIGS. 3A and 3B is obtained. After fixing and holding in a temperature range of 577° C. or higher for 2 to 3 minutes in a nitrogen atmosphere, the spread area of the braze (=the area of the braze spread from the 15 mm×20 mm area of the upper plate 32 in top view) was measured. The maximum brazing temperature was set at the melting temperature of the test material or less.
Specifically, the lower plate 31, which is the test piece in FIGS. 3A and 3B, was placed with the sacrificial material facing upward. The upper plate 32 in FIGS. 3A and 3B is a brazing sheet comprising an Al—Si brazing material, and the brazing material of the upper plate 32 is placed in contact with the sacrificial material of the lower plate 31 . As a matter of course, the upper plate 32 used in the wax spread test of each test piece used a brazing sheet of the same configuration.
Note that the two stainless steel plates 33 and the fixture 34 in FIG. 3B are for preventing positional deviation between the lower plate 31 and the upper plate 32 during holding.

In addition, when the holding time in the heated state in each of the above tests exceeds the predetermined time, the strength value does not change significantly, and the state of the molten brazing filler metal does not change significantly. A retention time of 2 minutes or longer in the post-application strength test, gap-filling test, and brazing test does not significantly affect the results.
As for the "brazability of the sacrificial material surface" indicated by the results of the solder spreading test, a value of 130 mm ² or more was judged to pass.

These results are shown in Table 5. In Table 5, those that do not satisfy the requirements of the present invention are indicated by underlining the values, and those that were not evaluated are indicated by "-" in the evaluation item column.

[Consideration of the results]
As shown in Tables 1 to 5, No. Nos. 1 to 8, 10 to 12, and 15 to 18 are test materials satisfying the component composition specified by the present invention.
And no. Nos. 1 to 7, 10 to 12, and 15 to 18 satisfy the component composition defined by the present invention, and thus showed a sufficiently high level of post-brazing strength.
In addition, No. No. 8 did not undergo a strength test after brazing. 5 had the same compositions of the core material, brazing material and sacrificial material, and the content of Mg in the intermediate layer was large. It is presumed that a numerical value higher than the strength after brazing of No. 5 can be obtained.

And no. Since 1 to 8, 10 to 12, and 15 to 18 satisfy the component composition defined by the present invention, favorable results were obtained in the gap filling test.
Also, No. Nos. 1, 2, 10 to 12, 15, and 16 satisfied the component composition specified by the present invention, and thus gave favorable results in the wax spread test.
In addition, No. 3-8, 17, 18 were not subjected to the wax spread test. However, no. 3 to 8 are No. 1 and 2, or substantially the same sacrificial material (a sacrificial material with a lower Mn content); 17 and 18 are Nos. It had the same sacrificial material as 10. Therefore, No. The fluidity of the molten brazing filler metal on the sacrificial material surfaces of No. 3 to No. 8 is as follows. As a result, the spread area of the wax is also about the same as No. 1 and No. 2. It is presumed to be about the same as No. 1 and No. 2. The fluidity of the molten brazing filler metal on the sacrificial material surfaces of 17 and 18 is No. As a result, the spreading area of the wax is also about the same as that of No. 10. It is estimated that it will be about the same as 10.

From these results, it can be concluded that not only the "strength after brazing" but also the "brazability" (the brazeability of the brazing material surface indicated by the results of the gap-filling test) can be achieved by the brazing sheet satisfying the component composition specified in the present invention. , and the brazeability of the sacrificial material surface indicated by the results of the braze spreading test) are also excellent, and it has been confirmed that both can be achieved at a high level.

On the other hand, No. In Nos. 9, 13, and 14, the Mn content of the sacrificial material was high, so the molten braze on the surface of the sacrificial material did not flow, and the solder spreading test did not reach the desired level. That is, No. Nos. 9, 13, and 14 were evaluated to be poor in brazeability.

In addition, the data of each test material is plotted on a graph in which the horizontal axis is the "Mn amount (mass%) of the sacrificial material" and the vertical axis is the "spreading area (mm ² ) of the brazing test", which is the result of the brazing spreading test. As a result, it was confirmed that there was a strong correlation between the two (indices on the vertical and horizontal axes). Specifically, it was confirmed on the graph that as the "Mn amount (% by mass) of the sacrificial material" decreased, the "spread area of the brazing filler metal (mm ² )" increased.
Therefore, based on this result, it became clear that the inventors' idea that the brazeability (brazeability of the sacrificial material surface) can be improved by suppressing the Mn amount of the sacrificial material is correct. .

REFERENCE SIGNS LIST 1 core material 2 sacrificial material 3 intermediate layer 4 brazing material 10 brazing sheet

Claims (9)

Aluminum comprising a core material, a sacrificial material provided on one side of the core material, a brazing material provided on the other side of the core material, and an intermediate layer provided between the core material and the brazing material An alloy brazing sheet,
The core material contains Si: 0.30% by mass or more and 1.00% by mass or less, Mn: 0.50% by mass or more and 2.00% by mass or less, Cu: 0.60% by mass or more and 1.20% by mass or less, Mg : 0.30 % by mass or more and 0.80% by mass or less, the balance being Al and unavoidable impurities,
The sacrificial material contains Si: 0.10% by mass or more and 1.20% by mass or less, Zn: 2.00% by mass or more and 7.00% by mass or less, Mn: 0.40% by mass or less, and the balance being Al and unavoidable consisting of impurities,
The intermediate layer contains Si: 0.05% by mass or more and 0.83 % by mass or less, Mn: 0.50% by mass or more and 2.00% by mass or less, Cu: 0.10% by mass or more and 0.95 % by mass or less, The balance consists of Al and unavoidable impurities,
An aluminum alloy brazing sheet , wherein the sacrificial material has a clad rate of 5% or more and 25% or less . 2. The aluminum alloy brazing sheet according to claim 1, wherein the intermediate layer further contains Mg: 0.20% by mass or less. 2. The intermediate layer further contains one or more of Ti: 0.30% by mass or less, Cr: 0.30% by mass or less, and Zr: 0.30% by mass or less. Or the aluminum alloy brazing sheet according to claim 2 . 3. The core material further contains one or more of Ti: 0.30 mass % or less, Cr: 0.30 mass % or less, and Zr: 0.30 mass % or less. The aluminum alloy brazing sheet according to claim 3 . 2. The sacrificial material further contains one or more of Ti: 0.30% by mass or less, Cr: 0.30% by mass or less, and Zr: 0.30% by mass or less. The aluminum alloy brazing sheet according to any one of claims 4 to 4. 6. The aluminum alloy brazing sheet according to any one of claims 1 to 5, wherein the brazing material comprises an Al-Si alloy or an Al-Si-Zn alloy. The aluminum alloy brazing sheet according to any one of claims 1 to 6, wherein the brazing material has a clad rate of 5% or more and 25% or less. The aluminum alloy brazing sheet according to any one of claims 1 to 7, wherein the intermediate layer has a clad rate of 5% or more and 25% or less. The aluminum alloy brazing sheet according to any one of claims 1 to 8, wherein the brazing sheet has a thickness of 0.35 mm or less.

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