JP2006150442A - Aluminum alloy brazing wire, and brazing method of aluminum alloy casting, and brazed liquid-cooled part - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a brazing wire which is excellent in workability and with which brazing of an aluminum alloy casting at a brazing temperature of 530 to 570°C is made possible. <P>SOLUTION: The aluminum alloy casting brazing wire is composed of an Al-Si-based alloy sheet of 5 to 15mass% in Si content, a hollow sheath constructed of a clad material composed of a Cu sheet in which mass of Cu with respect to the mass of the entire sheath corresponds to 22 to 37mass%, and a fluoride-based non-corrosive flux powder containing cesium fluoride filled into the sheath. The brazing wire is set in a brazing part of an attachment body composed of the brazed aluminum alloy casting and another member to be brazed and thereafter, the attachment body is heated and brazed. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a brazing wire used for brazing an aluminum alloy, an aluminum alloy brazing wire in which a flux is filled in an aluminum alloy sheath, and a low melting point aluminum alloy using the brazing wire. The present invention relates to a method of brazing a casting in a furnace and a liquid-cooled part manufactured by the brazing method.

  Generally, an aluminum-silicon alloy (Al-Si alloy) is used for cast products. This Al-Si alloy has a lower melting point than that of pure aluminum, and can be manufactured in a complicated shape with a mold, so that it is used for applications such as pistons and cylinder heads. In addition, it is used for applications such as building panels by utilizing the gray color. In particular, aluminum alloy die-cast products can be manufactured in complex shapes with high productivity, and in recent years, their production and use have increased.

Even when used in various applications, it is used in combination with a plurality of metal parts. There are various means as a method for joining aluminum alloy cast parts. However, when the joining surface is complicated or airtightness is required, the brazing method is heavily used.
Generally, a brazing material made of an aluminum alloy is used for brazing an aluminum alloy. And the brazing temperature is about about 600 degreeC normally.

As a brazing method for an aluminum material, a method using a potassium fluoride-based non-corrosive flux (commonly called “Nocolok” (registered trademark)) and an Al—Si based brazing material is widely known.
However, this “Nocolok” brazing method uses a flux having a eutectic composition of KF and AlF ₃ . Since the melting point of the eutectic point of KF and AlF ₃ is 560 to 570 ° C., and the melting point of JIS A4045 and A4047 Al—Si alloys used as the brazing material is 577 ° C. It is heated to about 600 ° C., which is about 30 ° C. higher than the melting point of the material.
By this heating, the oxide film on the surface of the aluminum material is dissolved and removed by the molten potassium fluoride-based flux, the wettability with the brazing material is extremely improved, and the flow diffusion of the molten brazing material is promoted. The brazing material that has flowed to the part where the joints are in contact with each other forms a fillet to join the members to be brazed.

  However, in the case of an aluminum alloy cast part, the joining target member is an Al—Si alloy of the same system as the brazing material. For this reason, at the brazing temperature of 600 ° C. when the potassium fluoride-based flux is used, there arises a problem that the parts to be joined themselves melt and the product shape cannot be maintained. This problem of brazing temperature can be solved by lowering the brazing temperature below the melting point of the aluminum alloy, so that measures have been conventionally taken to lower the melting point of the brazing material and lower the melting point of the flux.

Regarding the flux, a cesium fluoride-based non-corrosive flux having a melting point lower than that of the potassium fluoride-based flux has been developed.
On the other hand, as a low melting point brazing material, a Zn—Al alloy having a melting point of around 480 ° C. has been known for a long time (for example, Patent Document 1). However, in recent years, the development of an Al—Cu—Si alloy brazing material having a melting point of 520 to 550 ° C. has been reported because the flowability of the braze is poorer than that of the Al—Si alloy and the corrosion resistance of the fillet is inferior. .
Also, as a method for supplying flux and brazing material to the brazed joint, a brazing wire for brazing containing or containing flux has been proposed to improve work efficiency.

For example, Non-Patent Document 1 proposes a cored wire in which a brazing aluminum alloy material (JIS A4047) is used as a sheath and the core is filled with a “Nokorok” flux or a cesium fluoride-based non-corrosive flux.
In Patent Document 2, aluminum powder or an alloy thereof (JIS A1000 series) is used as a sheath, and a metal powder such as copper, silicon, zinc, etc. is mixed at a predetermined ratio with “Nokorok” flux or cesium fluoride noncorrosive flux. And the brazing wire with which the core of the said sheath was filled is proposed.
Furthermore, in Patent Document 3, each metal powder for obtaining an Al—Cu—Si ternary alloy composition and a cesium fluoride-containing fluoride-based non-corrosive flux powder are enclosed in an aluminum can, and 400 ° C. under vacuum. Describes the production of a flux-containing aluminum alloy brazing wire obtained by extruding a solid material heated and pressed into a wire.
“Industrial Materials”, published by Nikkan Kogyo Shimbun, June 2003 (Vol.51, No.6) p.90-91 JP-A-9-29482 US Pat. No. 5,418,072 JP-A-8-164492

However, the brazing wire proposed in Non-Patent Document 1 also has a brazing temperature of about 600 ° C. because an A4047 alloy having a melting point of 577 ° C. is used as the brazing material. For this reason, it cannot be used for brazing of an aluminum alloy casting having a melting point lower than 600 ° C.
Moreover, in the brazing wire proposed in Patent Document 2, if copper is selected as the metal powder to be filled in the sheath, the melting point becomes an alloy composition of around 550 ° C., and brazing at a temperature of about 570 ° C. is possible. Cannot be used for brazing castings having a temperature lower than 570 ° C. In order to apply to a wider range of casting alloys, it is necessary to fill a mixed powder of a plurality of metals such as copper and silicon to obtain a brazing material having a lower melting point. However, when mixing and filling a plurality of metal powders, filling in a uniform mixed state is very difficult due to the difference in particle size distribution and specific gravity. Further, since the metal powder to be filled is fine and the total surface area is very large, it is accompanied by a very large amount of oxides that inhibit brazing. For this reason, in order to obtain good brazing properties, it is necessary to use a large amount of flux, which causes an increase in manufacturing cost.

  Further, the wire-forming flux-containing aluminum alloy brazing wire proposed in Patent Document 3 can be brazed at a temperature of about 550 ° C. because the melting point of the brazing material is as low as about 530 ° C. However, there are difficulties in the manufacturing process, and the powder forming wire containing the flux has poor formability, and the bending process to the shape along the joint part of the casting, such as a ring shape, is also possible from the examples described in the same document. As can be seen, it must be carried out at a high temperature of 400 ° C., leading to an increase in manufacturing cost.

As described above, in the conventional brazing material, when Al—Si alloy castings are brazed and joined, as a result, an element composition that forms an Al—Cu—Si ternary alloy with a low melting point of the brazing material Even if the composition is achieved, the productivity cannot be improved, the manufacturing cost is high, and the processability is low, so that the usability is not good.
The present invention has been devised to solve such problems, and has a low brazing wire that is excellent in workability and enables brazing of an aluminum alloy casting at a brazing temperature of 530 to 570 ° C. The purpose is to provide at a cost. Furthermore, it aims at providing the method of brazing an aluminum alloy casting at low temperature using this brazing wire.

In order to achieve the object, the aluminum alloy brazing wire of the present invention includes a hollow sheath constructed from an Al—Si based alloy material and a Cu clad material, and cesium fluoride filled in the sheath. It is characterized by comprising a fluoride-based non-corrosive flux powder.
The clad material for constructing the sheath is composed of an Al—Si based alloy plate having a Si content of 5 to 15% by mass and a Cu plate corresponding to 22 to 37% by mass of Cu with respect to the mass of the entire sheath. It is preferable. The fluoride non-corrosive flux powder filled in the sheath preferably contains 10 mol% or more of CsF as a solid content.

In addition, the method for brazing an aluminum alloy casting according to the present invention includes arranging the aluminum alloy brazing wire after the aluminum alloy brazing wire is placed on a brazed portion of an assembly including the aluminum alloy casting to be brazed and the other brazed member. It is characterized by heating the body.
The heating is preferably performed by charging the assembled body into a heated furnace, particularly an inert gas atmosphere furnace heated to a temperature of 530 to 570 ° C.

The aluminum alloy casting to be brazed is made of a die-cast product, particularly an Al-Si alloy, and another aluminum alloy wrought material or aluminum alloy casting is assembled, and then the aluminum alloy brazing wire of the present invention is attached to the brazed portion. May be placed and brazed.
When the brazing method is applied, a liquid-cooled part in which an aluminum alloy lid is watertightly joined to a die-cast aluminum alloy casting having a water channel structure can be easily obtained. In addition, a liquid-cooled component in which an aluminum alloy channel member and a die-cast aluminum alloy case are watertightly joined can be easily obtained.

According to the present invention, an Al—Cu—Si alloy that melts at a temperature lower than 777 ° C. and is excellent in wettability and corrosion resistance is used for the brazing material. Furthermore, in order to lower the melting point, a fluoride flux containing cesium fluoride (CsF) is used, and a brazing wire in which the brazing material and the flux are integrated is arranged in the brazing portion.
Therefore, even a low melting point aluminum alloy casting, particularly an Al-Si die cast product having an eutectic point of about 577 ° C, can be brazed in a furnace without causing brazing defects. For this reason, it can contribute to the significant expansion of the range of use of Al-Si alloy cast products that require low-temperature brazing.

The inventors of the present invention are able to produce an aluminum alloy casting in which an Al—Si based alloy is frequently used due to good castability without causing brazing defects at a temperature lower than the eutectic temperature of the Al—Si based alloy. I have been studying how to braze well.
As a result, it is preferable to use an Al—Cu—Si alloy having a low melting point as the brazing material, it is preferable to use a fluoride-based non-corrosive flux containing CsF as the flux, and further, the brazing material and the flux component That can be brazed with high productivity by placing it in the brazed part of the assembly of the aluminum alloy casting and the other brazed member and inserting the assembly into an atmosphere furnace at a predetermined temperature. I found it.
Details will be described below.

Al-Cu-Si alloy brazing material The present invention makes the best use of the fact that the ternary eutectic point of Al-Cu-Si exhibits a low melting point. However, the Al—Cu—Si ternary eutectic alloy has extremely poor plastic workability. Therefore, not only is it difficult to form the sheath of the brazing wire, but even if the wire can be formed, it is difficult to bend it into a shape along the joint part.

Therefore, in the present invention, the three components are separately supplied as an Al—Si based alloy material and a Cu material so as to produce an Al—Cu—Si ternary eutectic alloy when heated by brazing. And the clad method was adopted as a supply means.
By using a clad material of an Al-Si alloy material and a Cu material, an Al-Cu-Si ternary copolymer having a melting point of 525 ° C is obtained by reacting (eutectic) the Al-Si alloy and Cu during brazing heating. Crystalline wax can be produced. As a result, brazing can be easily performed in a low temperature range of 530 to 560 ° C.

Moreover, by using both materials as clad materials, the amount of oxide film that is normally formed on the surface and inhibits brazing can be reduced, and the amount of flux to be filled can also be reduced.
Furthermore, both the Al—Si based alloy material and the Cu material constituting the clad material have good plastic workability. Since good plastic workability is maintained even after the clad material is formed, not only can the sheath wire be formed into a sheath shape and the flux filled into the sheath easily using a normal wire manufacturing facility, Bending process can be easily performed according to the joint shape of the brazed body. And even when using an automatic torch brazing apparatus, continuous supply can be performed without problems.

  In order to facilitate the formation of eutectic brazing when used as a clad material as described above, the Al—Si based alloy plate constituting the clad material has an Si content of 5 to 15% by mass, and Al—Si. The ratio of the system alloy plate and the Cu plate is preferably adjusted so that the mass of Cu with respect to the mass of the entire sheath corresponds to 22 to 37% by mass. If the amount of Si and / or Cu is out of these numerical ranges, the resulting braze composition and the Al—Cu—Si ternary eutectic composition (Cu; 26.7 mass%, Si; 5.3 mass%) ) Becomes too large, and brazing in the temperature range of 530 to 560 ° C. becomes difficult.

JIS A4343, A4045, A4047, 4N43, 4N45 etc. can be used as an Al-Si system alloy material with Si content of 5-15 mass%.
Since the specific gravity of Cu is 8.9 and the specific gravity of the Al—Si alloy is 2.7, the ratio of the cross-sectional area of the Cu material to the cross-sectional area of the sheath is 22 to 37 mass% of the Cu material relative to the mass of the sheath It can be satisfied by setting the clad rate of the plate-like sheath material before tube forming to 8 to 15%.
In addition, although the four forms as shown in FIG. 1 are assumed as the cross-sectional shape of the sheath clad with the Cu material, any may be used. It suffices if the conditions regarding the cladding rate are satisfied. The tube forming into a sheath shape is also deformed by a normal method.

Filling the inside of the fluoride-based non-corrosive flux sheath with a normal method is also performed.
As the filling flux, a flux having a low melting point and excellent non-corrosiveness is used. In order to omit the flux residue removal step after brazing, it is necessary to use fluoride-based non-corrosive flux powder. Further, in order to lower the melting point of the flux to the melting point of 525 ° C. or lower of the Al—Cu—Si ternary eutectic brazing alloy, it is essential to contain cesium fluoride (CsF).

As the flux, a fluoride-based flux used when brazing a normal aluminum alloy can be used. The compound form of the fluoride-based non-corrosive flux includes KAlF ₄ , K ₂ AlF ₅ , K ₃ AlF ₆ , AlF ₃ , KF, CsF, etc., but a mixture thereof is used as in the conventional case. However, since the melting point of the brazing filler metal itself is lowered in the present invention, the flux itself needs to have a lower melting point. For this reason, CsF is contained in the present invention. If the CsF content is less than 10 mol% of the entire fluoride-based flux, there is little effect of lowering the melting point of the flux, the melting point of the flux becomes higher than the melting point of the brazing material, and the flux may not melt during brazing. . Therefore, in the present invention, it is essential to contain 10 mol% or more of CsF as a solid content.

Since the aluminum alloy brazing wire of the present invention uses a brazing material with a small oxide film, it can be brazed even with a small amount of filled flux.
The mass of the flux with respect to the mass of the brazing wire, that is, the so-called filling rate does not need to be specified, and 20 to 40%, which is the same as the filling rate of the conventional cored wire, is sufficient.

  As mentioned above, brazing aluminum alloy filled with fluoride-based non-corrosive flux that uses Al-Si alloy material and Cu clad material as sheath and contains cesium fluoride to lower melting point When the wire is heated, first, the fluoride non-corrosive flux having a low melting point is melted at a temperature of 440 to 510 ° C., and the oxide film on the joined portion of the sheath material and the brazed body is removed. When further heated to exceed the Al-Cu-Si ternary eutectic temperature of 525 ° C, the sheath Al-Si alloy and Cu react (eutectic) and Al-Cu-Si ternary eutectic An alloy braze is formed, and the molten braze flows to the brazed joint at a brazing temperature of 530 to 570 ° C., and good brazing is achieved.

The aluminum alloy casting to be brazed and heat brazed is assembled with the other brazing material and an aluminum alloy brazing wire is placed on the brazed portion, and then the brazed portion is heated and brazed. There is no restriction on the brazing method. The usual brazing method is sufficient. It can be sufficiently brazed by charging in a furnace heated to a predetermined temperature and holding it for a predetermined time. However, in the present invention, an aluminum alloy brazing material that is easily oxidized is used. Therefore, brazing is also preferably performed in an inert gas in which the brazing material is not oxidized. In order to further prevent oxidation of the brazing material, it is preferable that the brazing atmosphere is once evacuated and then replaced with an inert gas such as nitrogen.

Next, a case where a liquid-cooled part is manufactured using the brazing method of the present invention will be described.
Usually, the liquid-cooled component as shown in FIG. 2 has a complex-shaped water channel inside, and cannot be manufactured in one step. For this reason, a method for producing a water channel portion having a complicated shape by a casting method such as die casting or a method for producing it by forging can be considered. Furthermore, when the water channel pitch is small, it may be produced by skiving or wire cutting. Then, for example, a water channel member 2 having a complicated shape manufactured by a wire cutting method is set in a die-cast case 1 to form a liquid cooling component.

As one form of the liquid-cooled part of the present invention, there may be mentioned one in which a water channel member having a complicated shape is set in a die-cast case and a cold and hot brazing method is adopted as means for obtaining a watertight structure.
At this time, if an Al—Si alloy having excellent fluidity is used as the case material, a complicated and thin member can be easily manufactured without causing casting defects. Furthermore, by adopting the die casting method, liquid-cooled parts can be manufactured at low cost.

  The die-cast case is manufactured by using a die-casting method that uses an Al—Si alloy having excellent castability as a raw material and is inexpensive. The channel member is also made of an Al—Si alloy having excellent castability, and is manufactured by using, for example, a die casting method. A channel member with a small channel pitch is produced by skiving or wire cutting. As the material at that time, an aluminum alloy wrought material such as 1000 series or 6000 series is used. Moreover, although a water channel member may be comprised from two members, in this case, it is comprised from the plate which supports it and the aluminum fin which comprises a water channel.

In order to secure the water tightness between the case 1 and the water channel member 2 manufactured by die casting, the brazing wire 3 bent into a required shape or cut to a required length is set on their mating surfaces. The brazing wire is preferably set in a recess provided in the die-cast case or the water channel member. Brazing is performed by inserting the brazing wire into an inert gas atmosphere furnace heated to a temperature of 530 to 570 ° C. with the brazing wire set.
The above-mentioned form combines a die-cast case and a complex-shaped water channel member, but the opposite form, that is, a complex-shaped water channel member produced by a casting method such as die-casting, is provided with a lid member made of wrought material or the like. In combination, the joints of the two may be watertight joined by a brazing method using a brazing wire.

Example 1:
Next, an example is shown in which brazing wires in which the cladding ratios of the Al—Si based alloy material and the Cu material as the sheath are variously changed are actually manufactured and brazed and tested.
Preparation of Al-Si-based alloy material and Cu clad sheath material A JIS A4045 plate having a thickness of 10 mm is sandwiched between two Cu plates having the thicknesses shown in Table 1 and fixed by welding the tips. 300 It was heated to ° C. and clad rolled to a thickness of 2 mm. Subsequently, intermediate annealing, cold rolling, and final annealing were performed to produce a clad sheath material having a thickness of 0.1 mm.
Table 1 also shows the Cu clad rate measured by observing the cross section of the sheath material, and the ratio of the mass of Cu to the sheath material mass calculated based thereon.
In addition, No. In the sheath materials 1 and 2, the mass of Cu with respect to the mass of the sheath material is in the range of 22 to 37 mass% of the range of the present invention. And No. In the sheath material of No. 3, the mass of Cu with respect to the mass of the sheath material is less than the range of the present invention. In the sheath material No. 4, the mass of Cu with respect to the mass of the sheath material is larger than the range of the present invention. Furthermore, as a conventional sheath material (No. 5), a sheath material having a thickness of 0.1 mm was produced from a JIS A4045 plate having a thickness of 20 mm without sandwiching a Cu plate by the same plate making process as described above.

Preparation of brazing wire Five kinds of sheath materials shown in Table 1 were cut into a width of 10 mm and a length of 20 mm, and wound twice or triple around a steel round bar with an outer diameter of 1 mm, and a wall thickness of 0.3 mm and a length of A brazing wire sheath with a thickness of 20 mm was prepared. One end of the sheath is closed with pliers, and a K-Cs-Al-F fluoride non-corrosive flux containing 48 mol% of cesium fluoride (Daiichi Rare Element Industrial Co., Ltd .; trade name " CF-2 ") After filling about 30 mg of powder, the other end was closed to form a brazing wire.
The flux filling rate is No. In the sheath material of 1-4, it is 29-32 mass%. It was 36 mass% in the sheath material of 5.

Brazing test thickness 1 mm, width 25mm, and the JIS-A3003 aluminum alloy plate length 55mm and the lower plate, thickness 1 mm, width 25mm, inverted T-where the JIS-A3003 aluminum alloy sheet of length 25mm and vertical plates A mold brazing test piece was assembled, and the brazing wire was set on one side of the line of intersection of the lower plate and the vertical plate. This assembly was heated in a nitrogen gas atmosphere furnace to 550 ° C. at a heating rate of 50 ° C./min, held at 550 ° C. for 3 minutes, and then cooled to room temperature at about 100 ° C./min.

Brazing property evaluation The brazing property was determined by observing the appearance of the inverted T-shaped test piece with the naked eye and a stereomicroscope and observing the erosion state of the base by observing the cross section at the center of the joint with an optical microscope.
Appearance evaluation of the joint is ○, where a sufficiently large fillet is formed on both the brazed wire set side and the opposite side, a part of the sheath material remains on the brazed wire set side or the fillet on the opposite side △ is a small one, and × is a case where no wax is generated.
Further, the erosion state of the substrate is measured by measuring the maximum depth of erosion (that is, melting of the substrate) due to the molten wax, and the maximum depth is 0.1 mm or less, and the maximum depth is 0.1 to 0. A sample having a maximum depth of 0.3 to 0.5 mm is indicated by ◯, and a sample having a maximum depth of 0.5 mm or more is indicated by ×.
The evaluation results are shown in Table 2.

As can be seen from the results in Table 2, the present invention is No. In the case of brazing using brazing wires of 1 or 2 sheath materials, both the brazing wire set side and the opposite side are well brazed. The erosion of the base that occurred on the brazing wire set side was also 0.3 mm or less.
On the other hand, No. 1 which is a comparative example and has a small Cu ratio. In the case of brazing using the brazing wire of No. 3 sheath material, a large amount of the sheath material remained on the brazing wire set side, and there was little brazing that flowed on the opposite side. In addition, No. with a large Cu ratio. In the case of brazing using the brazing wire of No. 4 sheath material, the base on the brazing wire set side was severely eroded. This is because when the ratio of Cu to the sheath material exceeds 37% by mass, Cu in the brazing wire becomes excessive, and reacts (eutectic) with the underlying aluminum alloy to be bonded to form an Al—Cu—Si ternary eutectic. As a result, it is presumed that severe erosion (erosion = melting) occurred in the substrate.
In addition, No. which is the conventional sheath material which does not contain Cu. In the case of brazing using the brazing wire No. 5, although the oozing of the melted flux was seen, the brazing wire remained in its original shape and no brazing was formed.
As explained above, it can be seen that by setting the ratio of the mass of Cu to the mass of the sheath to 22 to 37 mass%, it is possible to perform good brazing at a low temperature.

Example 2:
Next, an example in which an aluminum alloy casting is brazed using an aluminum alloy brazing wire incorporating a fluoride non-corrosive flux will be described.
For brazing evaluation, L = 30 mm, W = 50 mm, t = 6 mm die-cast material made of Al-7% Si-0.3% Mg alloy (AC4C), and L = 30 mm, W made of 3003 alloy. = 50 mm, t = 1 mm plate material was prepared.
A plate material was set up on the die-cast material, an inverted T-shaped brazing test piece was assembled, and the brazing wire was cut into a length of 50 mm and set on one side of the line of intersection of the lower plate and the vertical plate. This assembly was placed in an atmosphere furnace, and the inside of the atmosphere furnace was once evacuated and then replaced with nitrogen gas. Thereafter, in this furnace, the assembly was heated to 520 ° C. in about 40 minutes, further held at each temperature of 520 to 580 ° C. for 5 minutes, and then brazed by cooling.

After brazing , the inverted T-shaped brazing specimen was cut and the brazing state was visually observed to evaluate brazing. The results are shown in Table 3.
The evaluations in the table are indicated as “Good” when the die-cast material and the plate material are brazed without any problem by appearance observation, and indicated as “Poor” when there is a part where the brazing is defective.

《Reference example》
In order to confirm the effectiveness of the fluoride-based non-corrosive flux-containing aluminum alloy brazing wire utilization technology of the present invention, as a vertical material, 4343 having a solidus temperature of 577 ° C. as a brazing material on both sides of a 3003 alloy plate. A brazing test was performed using a so-called brazing clad material obtained by cladding an alloy plate at a rate of 10% and using a normal Nocolok (registered trademark) powder as a flux.
A die-cast material having the same size as that of the example was used as a base material, and after applying noco-lock to the surface of the base material to be brazed, the brazing clad material was erected to prepare an assembly for an inverted T-shaped brazing test.
The assembly was placed in an atmospheric furnace and heated as in the example. In this case, the assembly was heated in a furnace to 560 ° C. in about 40 minutes, further held at each temperature of 560 to 590 ° C. for 5 minutes, and then brazed by cooling.
In the same manner as in the examples, after brazing, the inverted T-shaped brazing specimen was cut and the brazing state was visually observed to evaluate the brazing property. The results are also shown in Table 3.

As is clear from the results in Table 3, it was found that when the brazing wire with built-in flux was applied to the brazed part and brazed in a temperature range of 530 to 570 ° C., a good brazed part was obtained.
On the other hand, when the brazing temperature is lower than 530 ° C., it can be seen that the brazing material does not melt and cannot be brazed. On the other hand, when brazing at a high temperature exceeding 570 ° C., the AC4C material itself, which is the base material, partially melts, and good brazing has not been achieved.

In the reference example using the 4343 alloy as the brazing material, the brazing material does not melt even at a brazing temperature of 560 to 570 ° C., and good brazing has not been achieved. Further, when brazing at a temperature exceeding 580 ° C., the AC4C material itself, which is the base material, is partially melted, and satisfactory brazing has not been achieved.
Thus, a fluoride system in which an Al-Si-based alloy material for producing an Al-Cu-Si based alloy having a low eutectic temperature and a Cu clad material are used as a brazing material and the melting temperature is lowered by further containing CsF. By using a flux, an aluminum alloy casting having a low eutectic temperature can be brazed without problems at a low brazing temperature.

The figure explaining the cross-sectional shape of the sheath by the clad material of Al-Si system alloy material and Cu material The figure explaining the section structure of the liquid cooling parts using a die-casting member

Explanation of symbols

1: Die-cast case 2: Channel member 3: Brazing wire

Claims (11)

  Aluminum comprising a hollow sheath constructed from an Al-Si alloy material and a Cu clad material, and a fluoride non-corrosive flux powder containing cesium fluoride filled in the sheath Alloy brazing wire.   The clad material for constructing the sheath is composed of an Al—Si based alloy plate having a Si content of 5 to 15% by mass and a Cu plate corresponding to 22 to 37% by mass of Cu with respect to the mass of the entire sheath. The aluminum alloy brazing wire according to claim 1.   The aluminum alloy brazing wire according to claim 1 or 2, wherein the fluoride non-corrosive flux powder contains 10 mol% or more of CsF as a solid content.   After the aluminum alloy brazing wire according to any one of claims 1 to 3 is arranged in a brazed portion of an assembly composed of an aluminum alloy casting to be brazed and the other brazed member, the assembly A method for brazing an aluminum alloy casting characterized by heating the steel.   The method for brazing an aluminum alloy casting according to claim 4, wherein the heating is performed by charging the assembly into a heated furnace.   The method for brazing an aluminum alloy casting according to claim 4 or 5, wherein the brazing is performed by heating in a temperature range of 530 to 570 ° C.   The method for brazing an aluminum alloy casting according to any one of claims 4 to 6, wherein the heating furnace is an inert gas atmosphere furnace.   The method for brazing an aluminum alloy casting according to any one of claims 4 to 7, wherein the aluminum alloy casting to be brazed is a die-cast product.   The method for brazing an aluminum alloy casting according to claim 8, wherein the die-cast product is made of an Al-Si alloy.   A liquid-cooled component obtained by watertightly bonding an aluminum alloy lid to an aluminum alloy casting having a water channel structure using the brazing method according to any one of claims 4 to 9.   A liquid-cooled component obtained by watertightly bonding an aluminum alloy channel member and a die-cast aluminum alloy case using the brazing method according to any one of claims 4 to 9.

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