JP2019013981A - Flux free brazing method of aluminum material and aluminum alloy member for flux free brazing - Google Patents

Abstract

To provide a flux free brazing method capable of obtaining a stable joining state even in a joint having an open part.SOLUTION: In a flux free brazing method of an aluminum material where a brazing sheet cladded with an Al alloy brazing filler metal containing 3-13 mass% Si and 0.1-5.0 mass% Mg on one surface or both surfaces of an Al-made core material and the aluminum alloy member of a joining object member are assembled and brazed without using a flux in a non-oxidation gas atmosphere, brazing is performed by containing one or more kinds of metal elements having a melting point of 350°C or lower and a standard free energy of formation (ΔG°) of an oxide of higher than -150 (kg cal/gr mol O) at 600°C by 0.01-0.5 mass% respectively in the aluminum alloy member.SELECTED DRAWING: None

Description

  The present invention relates to a flux-free brazing method for an aluminum material and an aluminum alloy member for flux-free brazing.

  Heat exchangers for automobiles and the like are manufactured by brazing and joining after assembling members. In order to perform good brazing, it is necessary to destroy the oxide film on the surface of the alloy member, and in order to destroy the oxide film on the material surface, a method of brazing using a flux is widely known. . As a method of performing brazing and joining using a flux, a method using a noclock flux has become the mainstream. However, when an aluminum alloy containing Mg is used to increase the strength, there is a problem that Mg reacts with the flux and a flux inactivation reaction (generation of Mg fluoride or the like) occurs. is there. Therefore, a method of performing brazing joining without using a flux has been proposed.

As a method for performing good brazing without using a flux, it has been proposed to use an Al—Si—Mg alloy as a brazing material. By using an Al—Si—Mg-based alloy for the brazing material, the Mg in the brazing material reduces and decomposes the Al oxide film (Al ₂ O ₃ ) on the surface of the joint near the melting point of the brazing material at the time of brazing. Since the oxide film on the alloy surface is destroyed, good brazing can be performed.
For example, in Patent Document 1, while adding Mg to the brazing material of the fin material and brazing sheet and adjusting the amount of Mg to be added, while solving the problem of scale adhesion in the furnace during vacuum brazing This makes it possible to manufacture high-strength and lightweight heat exchangers.
In Patent Document 2, as a flux-free brazing method in an inert gas atmosphere, elements such as Ag, Be, Bi, and misch metal are added to an Al alloy for a core material containing Mg, Si, or the like. It has been proposed to use a clad Al alloy for brazing material to improve the wet spreadability during brazing.

Japanese Patent Laid-Open No. 07-145439 Japanese Patent No. 4996255

As described above, in flux-free brazing using an Al—Si—Mg-based brazing material, Mg in the brazing material that has been melted and activated reductively decomposes the Al oxide film (Al ₂ O ₃ ) on the surface of the joint. It becomes possible to join. In addition, for obstructive surface joints that are not easily affected by the atmosphere, joints that combine brazing sheets with brazing materials and brazed sheets and brazing materials that do not have brazing materials due to the decomposition of the oxide film by Mg With a joint that combines a member (bare material), a good joined state can be obtained.

  However, in the case of a joint shape having an open portion that is easily influenced by the atmosphere, it is difficult to obtain a sufficient joined state. In particular, when a brazing sheet and a bare material are combined and joined, decomposition of the Al oxide film on the surface of the bare material is difficult to proceed, and it is difficult to obtain sufficient joining. Furthermore, when using a bare material to which Mg is added for weight reduction, strength enhancement, etc., the MgO film which is a stable oxide film which is difficult to be decomposed easily grows at the time of brazing, and bonding is significantly hindered. . Therefore, a flux-free brazing method that can obtain a stable joint state even in a joint having an open portion is strongly desired.

  The present invention has been made in the background of the above circumstances, and an object thereof is to provide a flux-free brazing method and an aluminum alloy member for flux-free brazing that can obtain a stable joined state even in a joint having an open portion. To do.

By adding a metal element having a low melting point and a high standard free energy of formation of oxide to the bare alloy, the present inventors altered the dense Al oxide film of the bare material and decomposed it during brazing. As a result, it was discovered that the joining state by brazing between the brazing sheet and the bare material was improved.
On the bare metal surface to which the low melting point element is added, in order to suppress the growth of a dense oxide film by concentrating the low melting point element on the bare material surface during the brazing temperature rising process, It is thought that the oxide film was easily decomposed when contacted. Similarly, on the bare material surface to which Mg is added, low melting point elements are concentrated on the bare material surface during the brazing temperature rising process, and the growth of the MgO film is suppressed, so that a stable bonding state is obtained. Conceivable. In addition, when a low melting point element having a low standard free energy of formation of oxide is added to the bare material, the low melting point element concentrated on the surface forms an oxide layer and inhibits bonding. It is important to select a low-melting-point element having a high standard free energy of formation of oxide.

That is, among the flux-free brazing methods for an aluminum material of the present invention, the first invention is that an Al alloy brazing material containing 3 to 13 mass% Si and 0.1 to 5.0 mass% Mg is an Al core. A flux-free brazing method for an aluminum material in which a brazing sheet clad on one or both surfaces of a material and an aluminum alloy member to be joined are assembled and brazed in a non-oxidizing gas atmosphere without using a flux. ,
In the aluminum alloy member, one or two metal elements having a melting point of 350 ° C. or lower and a standard free energy of formation (ΔG °) of oxide at 600 ° C. higher than −150 (kg cal / gr mol O ₂ ) It contains 0.01 to 0.5 mass% of seeds or more.

  The flux-free brazing method for an aluminum material according to a second aspect of the present invention is the method according to the first aspect, wherein the aluminum alloy member includes Bi: 0.01 to 0.5 mass%, In: 0. 01-0.5 mass%, Sn: 0.01-0.5 mass%, K: 0.01-0.5 mass%, Se: 0.01-0.5 mass%, Na: 0.01-0.5 mass% , Pb: One or more of 0.01 to 0.5 mass% are contained.

  A flux-free brazing method for an aluminum material according to a third aspect of the present invention is the method according to the first aspect, wherein the aluminum alloy member contains Bi: 0.01 to 0.5 mass% as the metal element, , In: 0.01 to 0.5 mass%, Sn: 0.01 to 0.5 mass%, K: 0.01 to 0.5 mass%, Se: 0.01 to 0.5 mass%, Na: 0.01 It is characterized by containing 1 type (s) or 2 or more types of -0.5mass%, Pb: 0.01-0.5mass%.

  In the flux-free brazing method for an aluminum material according to a fourth aspect of the present invention, in any one of the first to third aspects of the present invention, the aluminum alloy member further contains 0.1 to 0.7 mass% of Mg. It is characterized by that.

  In the flux-free brazing method for an aluminum material according to a fifth aspect of the present invention, in any one of the first to fourth aspects of the present invention, the brazing material contains the metal element, and Bi: 0 as the metal element. .01-0.5 mass%, In: 0.01-0.5 mass%, Sn: 0.01-0.5 mass%, K: 0.01-0.5 mass%, Se: 0.01-0.5 mass %, Na: 0.01 to 0.5 mass%, Pb: 0.01 to 0.5 mass%, or one or more thereof.

  A flux-free brazing method for an aluminum material according to a sixth aspect of the present invention is the method according to any one of the first to fourth aspects, wherein the brazing material contains the metal element, and Bi: 0 as the metal element. .01-0.5 mass%, and In: 0.01-0.5 mass%, Sn: 0.01-0.5 mass%, K: 0.01-0.5 mass%, Se: 0.0. It contains one or more of 01 to 0.5 mass%, Na: 0.01 to 0.5 mass%, and Pb: 0.01 to 0.5 mass%.

  A flux-free brazing method for an aluminum material according to a seventh aspect of the present invention is the method according to any one of the first to sixth aspects of the present invention, wherein the thickness of the oxide film on the surface of the joint portion is the temperature raising process of the brazing. In particular, the brazing is performed so that the actual temperature of the joint portion is 20 nm or less when the actual temperature is 550 ° C.

  The flux-free brazing method for an aluminum material according to an eighth aspect of the present invention is the method according to any one of the first to seventh aspects, wherein the thickness of the MgO film on the surface of the joint is the temperature rising process of the brazing. Among them, the brazing is performed so that the actual temperature of the joint portion is 2 nm or less when the actual temperature is 550 ° C.

  A flux-free brazing method for an aluminum material according to a ninth aspect of the present invention is the method according to any one of the first to eighth aspects, wherein the non-oxidizing gas atmosphere has an oxygen concentration of 100 ppm or less. It is characterized by an atmosphere.

The aluminum alloy member for flux-free brazing according to the tenth aspect of the present invention is a non-oxidizing material having an oxygen concentration of 100 ppm or less using an Al alloy brazing material containing 3 to 13 mass% Si and 0.1 to 5.0 mass% Mg. A flux-free aluminum alloy member for brazing that is brazed without using flux in a reactive gas atmosphere,
One or two metal elements having a melting point of 350 ° C. or lower and a standard free energy of formation (ΔG °) of oxide at 600 ° C. higher than −150 (kg cal / gr mol O 2) in the aluminum alloy member. Each of these is characterized by containing 0.01 to 0.5 mass%.

  The aluminum alloy member for flux-free brazing according to an eleventh aspect of the present invention is the metal element according to the tenth aspect of the present invention, wherein Bi: 0.01 to 0.5 mass%, In: 0.01 to 0.5 mass% , Sn: 0.01-0.5 mass%, K: 0.01-0.5 mass%, Se: 0.01-0.5 mass%, Na: 0.01-0.5 mass%, Pb: 0.01 It contains 1 type or 2 types or more of -0.5 mass%, It is characterized by the above-mentioned.

  An aluminum alloy member for flux-free brazing according to a twelfth aspect of the present invention, in the tenth aspect of the present invention, contains Bi: 0.01 to 0.5 mass% as the metal element, and In: 0.01 -0.5 mass%, Sn: 0.01-0.5 mass%, K: 0.01-0.5 mass%, Se: 0.01-0.5 mass%, Na: 0.01-0.5 mass%, One or more of Pb: 0.01-0.5mass% is contained, It is characterized by the above-mentioned.

  According to a thirteenth aspect of the present invention, there is provided the flux-free brazing aluminum alloy member according to any one of the tenth to twelfth aspects of the present invention, wherein the brazing material contains the metal element, and Bi: 0 as the metal element. .01-0.5 mass%, In: 0.01-0.5 mass%, Sn: 0.01-0.5 mass%, K: 0.01-0.5 mass%, Se: 0.01-0.5 mass %, Na: 0.01 to 0.5 mass%, Pb: 0.01 to 0.5 mass%, or one or more thereof.

  According to a fourteenth aspect of the present invention, there is provided the flux-free brazing aluminum alloy member according to any one of the tenth to twelfth aspects of the present invention, wherein the brazing material contains the metal element, and Bi: 0 .01-0.5 mass%, and In: 0.01-0.5 mass%, Sn: 0.01-0.5 mass%, K: 0.01-0.5 mass%, Se: 0.0. It contains one or more of 01 to 0.5 mass%, Na: 0.01 to 0.5 mass%, and Pb: 0.01 to 0.5 mass%.

  The aluminum alloy member for flux-free brazing according to the fifteenth aspect of the present invention is characterized in that in any one of the tenth to fourteenth aspects of the present invention, Mg: 0.1 to 0.7 mass% is further contained.

  Hereinafter, the reasons for limiting the components and the like will be described.

1. Aluminum alloy member One or more metal elements having a melting point of 350 ° C. or lower and a standard free energy (ΔG °) of oxide at 600 ° C. higher than −150 (kg cal / gr mol O ₂ ): 0 .01 to 0.5 mass%
Since the above metal elements are concentrated on the bare material surface during brazing, the growth of a dense Al oxide film or MgO film is suppressed. If the content is less than 0.01 mass%, this effect is insufficient, and if the content is 0.5 mass% or more, the effect is saturated. Therefore, the content of the metal element is set in the above range. The lower limit is more preferably 0.05 mass% and the upper limit is more preferably 0.3 mass%. Moreover, as said metal element, Bi, In, Sn, K, Se, Na, Pb is mentioned suitably.

Mg: 0.1-0.7 mass%
Mg added to the aluminum alloy member forms Mg2Si by forming a compound with Si added to the bare material and Si diffused from the brazing material, thereby increasing the material strength. Also, the Al oxide film (Al2O3) on the bare material surface is reduced and decomposed. If the content is less than 0.1 mass%, the effect is insufficient. If the content exceeds 0.7 mass%, the MgO film tends to grow on the bare material surface in the joint having an open portion, and the bonding is hindered. The Therefore, when Mg is contained if desired, the content is set within the above range. It is more desirable that the lower limit is 0.2 mass% and the upper limit is 0.6 mass%.

  In addition, low melting point elements such as Bi, In, and Sn added to aluminum alloy members have a low solid solubility in aluminum, and therefore melt at the melting point of the low melting point element alone in the aluminum material depending on the heat treatment conditions of the material manufacturing process. And concentrated on the surface of the aluminum material. Since the surface of the material enriched with low melting point elements is susceptible to corrosion due to the weakened oxide film, hydrated oxide accumulates on the surface of the material when corrosion progresses before brazing, impeding bonding during brazing. There is a case. In this case, if Mg and a low melting point element are added together, a compound or the like can be formed and the melting point can be raised, so that surface concentration during the raw material manufacturing process can be suppressed. However, in this case as well, in the brazing temperature raising process up to about 600 ° C., the low melting point element is concentrated on the surface of the material before the melting of the brazing, so the above-mentioned effect of suppressing the growth of the MgO film is maintained.

  In addition, in the aluminum alloy of the present invention, in addition to Al and the above-described trace elements, by mass%, Mn: 0.2 to 2.5%, Cu: 0.05 to 1.0%, Si: 0.1 -1.2%, Fe: 0.1-1.0% etc. can be contained.

2. Brazing sheet (1) brazing material Si: 3 to 13 mass%
Si added to the Al alloy brazing material lowers the melting point of the brazing material and generates a molten brazing material necessary for joining at a temperature equal to or higher than the eutectic temperature at the time of brazing temperature rise. If the Si content is less than 3%, the amount of liquid phase produced is insufficient and sufficient fluidity cannot be obtained. If the Si content exceeds 13%, the primary crystal Si rapidly increases and the workability deteriorates. Sometimes joint erosion is significantly accelerated. Therefore, the content of Si in the brazing material is set within the above range. For the same reason, it is more preferable to set the lower limit to 5% and the upper limit to 12%.

Mg: 0.1-5.0 mass%
Mg acts on a dense oxide film (Al2O3 film) generated on the surface of the material in the brazing temperature rising process to decompose the oxide film, thereby improving the wettability and fluidity of the brazing. However, if the Mg content is less than 0.1 mass%, the decomposition action of the oxide film cannot be sufficiently obtained, and if it exceeds 5.0 mass%, the brazing filler metal strength becomes too high and the workability is lowered. For this reason, the content of Mg in the brazing material is preferably within the above range. For the same reason, the Mg content is more preferably 0.2% at the lower limit and 3.0% at the upper limit.

One or more metal elements having a melting point of 350 ° C. or lower and a standard free energy of formation (ΔG °) of oxide at 600 ° C. higher than −150 (kg cal / gr mol O ₂ ): 0.01 to 0.5 mass%
Since the metal elements described above are concentrated on the surface of the brazing material during brazing, the growth of a dense Al oxide film or MgO film is suppressed. If the content is less than 0.01 mass%, this effect is insufficient, and if the content is 0.5 mass% or more, the effect is saturated. Therefore, the content of the metal element is set in the above range. The lower limit is more preferably 0.05 mass% and the upper limit is more preferably 0.3 mass%. Moreover, as said metal element, Bi, In, Sn, K, Se, Na, Pb is mentioned suitably.
Further, among these elements, Bi, In, Sn, and Pb have the effect of lowering the surface tension of the molten solder and improving the wetting and spreading property of the brazing material, and in particular, Bi is preferably used because of its high effect. Can do.

(2) Core material The composition of the Al core material is not particularly limited, and any commonly used aluminum material can be used without any problem. However, in brazing with an Al—Si alloy brazing material, the product temperature is heated to around 600 ° C., so if an alloy member having a lower solidus temperature is used, it is difficult to ensure structural dimensional accuracy after brazing. . In the present invention, any aluminum alloy that does not cause this problem can be used, but it is preferable to use JIS A1000 series, A3000 series, and A6000 series alloys that are excellent in thermal conductivity and strength.

  According to the present invention, by adding a metal element having a low melting point and a high standard free energy of oxide formation to the bare material alloy, the dense Al oxide film on the surface of the bare material is altered and decomposed during brazing. It becomes easy and it becomes possible to improve the joining state after brazing.

It is a figure which shows the brazing evaluation model in the Example of this invention. Similarly, it is a figure which shows a junction part width | variety.

Hereinafter, an embodiment of the present invention will be described.
The aluminum alloy member of the present invention can be produced by, for example, a conventional method.
First, an aluminum alloy is prepared by preparing the composition of the present invention. The melting is performed by a semi-continuous casting method. The obtained aluminum alloy ingot is homogenized under predetermined conditions. That is, the homogenization treatment conditions are a treatment temperature of 350 to 600 ° C. and a treatment time of 1 to 10 hours. Thereafter, the aluminum alloy member of the present invention is obtained through soaking, hot rolling, cold rolling and the like. The aluminum alloy member can be manufactured, for example, as a fin material for a heat exchanger. The soaking is preferably performed at a temperature equal to or less than the homogenization temperature and processing time, and a temperature of 350 to 500 ° C and a holding time of 1 to 10 hours. In cold rolling, cold rolling can be performed at a total rolling reduction of 75% or more, intermediate annealing can be performed at a temperature of 300 to 400 ° C., and then final rolling at a rolling rate of 40% can be performed. The intermediate annealing may not be performed.

  When the fin material for the heat exchanger is obtained by the cold rolling or the like, thereafter, corrugating or the like is performed as necessary. The corrugating process can be performed by passing between two rotating molds, can be processed satisfactorily, and exhibits excellent formability.

The fin material obtained in the above process is used for brazing as a constituent member of a heat exchanger in combination with other constituent members (such as a tube and a header). As other constituent members, an Al alloy brazing material containing 3 to 13 mass% Si and 0.1 to 5.0 mass% Mg is composed of a brazing sheet clad on one or both sides of an Al core material. Use. Brazing is performed without using flux in a non-oxidizing gas atmosphere. The non-oxidizing gas atmosphere preferably has an oxygen concentration of 100 ppm or less.
The brazing is performed such that the thickness of the oxide film on the surface of the joint is 20 nm or less when the actual temperature of the joint is 550 ° C. during the temperature raising process of the brazing. When the member contains Mg, the thickness of the MgO film is 2 nm or less when the actual temperature of the joint is 550 ° C. during the brazing temperature rising process. desirable. The thickness of the oxide film or MgO film in the brazing temperature rising process is the oxygen concentration in the atmosphere, the amount of Mg in the alloy exposed to the atmosphere, the brazing temperature rising rate, the airtightness of the brazing furnace, the brazing furnace However, any of the conditions is not particularly limited in order to adjust in consideration of these factors comprehensively.

  According to the brazing described above, by adding a metal element having a low melting point and a high standard free energy of formation of oxide to the bare material alloy, the dense Al oxide film on the surface of the bare material is altered and brazed. Since it becomes easy to be disassembled sometimes, a stable joint state can be obtained even in a joint having an open portion.

  A brazing material having a composition shown in Tables 1 to 5 (the balance Al and inevitable impurities), a JIS A1100 alloy (Al-0.15 mass% Si-0.4 mass% Fe-0.1 mass% Cu) prepared as a core material, JIS A3003 alloy (Al-1.2 mass% Mn-0.3 mass% Si-0.4 mass% Fe-0.1 mass% Cu), JIS A3005 alloy (Al-1.2 mass% Mn-0.3 mass% Si-0. 4 mass% Mg-0.4 mass% Fe-0.1 mass% Cu-0.05 Zn), clad in combination with JIS A6063 alloy (Al-0.6 mass% Mg-0.4 mass% Si-0.25 mass% Fe) Aluminum material was prepared. As the aluminum clad material, various composition brazing materials were made to have a clad rate of 5% and finished to a thickness of 0.3 mm equivalent to H14.

  Moreover, the corrugated fin of the aluminum bear material (0.1-mm thickness) of the alloy composition shown to Tables 1-5 was prepared as brazing object member. The aluminum bare material is based on JIS A1100 alloy (Al-0.15 mass% Si-0.4 mass% Fe-0.1 mass% Cu) and JIS A3003 alloy (Al-1.2 mass% Mn-0.3 mass%) as a base alloy. Si-0.4 mass% Fe-0.1 mass% Cu) and JIS A7072 alloy (Al-1.0 mass% Zn-0.1 mass% Si-0.25 mass% Fe) were prepared and re-melted into various base alloys. Bi, In, Sn, K, Se, Na, Pb, and Mg were added, and various aluminum alloy bare materials shown in Tables 1 to 5 were melted. In this embodiment, the aluminum bare material corresponds to the aluminum alloy member of the joined member of the present invention.

  A tube having a width of 25 mm was manufactured using the aluminum clad material, and as shown in FIG. 1, the tube 12 and the corrugated fin 11 were combined to form a core 10 having 15 stages of tubes and a length of 300 mm as a brazing evaluation model. . The core was heated to 600 ° C. in a brazing furnace in a nitrogen gas atmosphere adjusted to various oxygen contents, and the brazing state was evaluated. In addition, although various joining tests were performed in a batch type furnace consisting of two chambers, a heating chamber and a cooling chamber, which were replaced with nitrogen gas, in order to investigate the oxide film and MgO film thicknesses at 550 ° C. in various tests, Using the core cooled at an ultimate temperature of 550 ° C., the oxide film thickness and the MgO film thickness on the surface of the joint were examined by a depth profile using an X-ray photoelectron spectrometer.

O Brazing property and joining rate The joining rate was calculated | required with the following formula and the superiority / inferiority between each sample was evaluated.
Fin joint rate = (total joint length after fin and tube brazing / total contact length before fin and tube braze) × 100

-Joint width evaluation The brazed joint state is not limited to the above-mentioned joint ratio, but in order to confirm the improvement of fillet forming ability, which is the object of the present invention, as shown in FIG. The points were measured, and the superiority or inferiority was evaluated by the average value.
While all of the examples showed good brazing properties, in the comparative example, sufficient joining was not obtained at a joining rate of 50% or less.

10 Core 11 Corrugated fin 12 Tube 13 Joint part

That is, among the flux-free brazing methods for an aluminum material of the present invention, the first invention is that an Al alloy brazing material containing 3 to 13 mass% Si and 0.1 to 5.0 mass% Mg is an Al core. A brazing sheet clad on one or both sides of a material and a bare aluminum alloy member, which is a member to be joined , and brazed without using flux in a non-oxidizing gas atmosphere. A method,
In the aluminum alloy member, one or two metal elements having a melting point of 350 ° C. or lower and a standard free energy of formation (ΔG °) of oxide at 600 ° C. higher than −150 (kg cal / gr mol O ₂ ) It contains 0.01 to 0.5 mass% of seeds or more.

A flux-free brazing method for an aluminum material according to a seventh aspect of the present invention is the method according to any one of the first to sixth aspects, wherein the non-oxidizing gas atmosphere has an oxygen concentration of 100 ppm or less. It is characterized by an atmosphere.

The aluminum alloy member for flux-free brazing according to the eighth aspect of the present invention is a non-oxidizing material having an oxygen concentration of 100 ppm or less using an Al alloy brazing material containing 3 to 13 mass% Si and 0.1 to 5.0 mass% Mg. a aluminum alloy member for with flux free brazing a bare material to be brazed without flux in sexual gas atmosphere,
In the aluminum alloy member, one or two metal elements having a melting point of 350 ° C. or lower and a standard free energy of formation (ΔG °) of oxide at 600 ° C. higher than −150 (kg cal / gr mol O ₂ ) It contains 0.01 to 0.5 mass% of seeds or more.

The aluminum alloy member for flux-free brazing according to the ninth aspect of the present invention is the metal element according to the eighth aspect , wherein Bi: 0.01 to 0.5 mass%, In: 0.01 to 0.5 mass%. , Sn: 0.01-0.5 mass%, K: 0.01-0.5 mass%, Se: 0.01-0.5 mass%, Na: 0.01-0.5 mass%, Pb: 0.01 It contains 1 type or 2 types or more of -0.5 mass%, It is characterized by the above-mentioned.

An aluminum alloy member for flux-free brazing according to a tenth aspect of the present invention contains Bi: 0.01 to 0.5 mass% as the metal element in the eighth aspect of the present invention, and further, In: 0.01 -0.5 mass%, Sn: 0.01-0.5 mass%, K: 0.01-0.5 mass%, Se: 0.01-0.5 mass%, Na: 0.01-0.5 mass%, One or more of Pb: 0.01-0.5mass% is contained, It is characterized by the above-mentioned.

An aluminum alloy member for flux-free brazing according to an eleventh aspect of the present invention is the aluminum alloy member for brazing according to any one of the eighth to tenth aspects of the present invention, wherein the brazing material contains the metal element, and Bi: 0 as the metal element. .01-0.5 mass%, In: 0.01-0.5 mass%, Sn: 0.01-0.5 mass%, K: 0.01-0.5 mass%, Se: 0.01-0.5 mass %, Na: 0.01 to 0.5 mass%, Pb: 0.01 to 0.5 mass%, or one or more thereof.

The aluminum alloy member for flux-free brazing according to a twelfth aspect of the present invention is the aluminum alloy member for brazing according to any one of the eighth to tenth aspects of the present invention, wherein the brazing material contains the metal element, and Bi: 0 as the metal element. .01-0.5 mass%, and In: 0.01-0.5 mass%, Sn: 0.01-0.5 mass%, K: 0.01-0.5 mass%, Se: 0.0. It contains one or more of 01 to 0.5 mass%, Na: 0.01 to 0.5 mass%, and Pb: 0.01 to 0.5 mass%.

The aluminum alloy member for flux-free brazing according to the thirteenth aspect of the present invention is characterized in that in any of the eighth to twelfth aspects of the present invention, Mg: 0.1 to 0.7 mass% is further contained.

An aluminum alloy member for flux-free brazing according to an eighth aspect of the present invention is a flux-free material used as a bare member to be joined for flux-free brazing with an Al alloy brazing material containing Mg in a non-oxidizing gas atmosphere. An aluminum alloy member for brazing,
One or two metal elements having a melting point of 350 ° C. or lower and a standard free energy of formation (ΔG °) of oxide at 600 ° C. higher than −150 (kg cal / gr mol O 2) in the aluminum alloy member. Each of these is characterized by containing 0.01 to 0.5 mass%.

Claims (15)

A brazing sheet in which an Al alloy brazing material containing 3 to 13 mass% Si and 0.1 to 5.0 mass% Mg is clad on one or both sides of an Al core material and an aluminum alloy member to be joined are assembled. A flux-free brazing method for an aluminum material that is brazed without using a flux in a non-oxidizing gas atmosphere,
One or two metal elements having a melting point of 350 ° C. or lower and a standard free energy of formation (ΔG °) of oxide at 600 ° C. higher than −150 (kg cal / gr mol O 2) in the aluminum alloy member. A flux-free brazing method for an aluminum material characterized by containing 0.01 to 0.5 mass% of each of the above.   In the aluminum alloy member, Bi: 0.01 to 0.5 mass%, In: 0.01 to 0.5 mass%, Sn: 0.01 to 0.5 mass%, K: 0.01 to Containing one or more of 0.5 mass%, Se: 0.01 to 0.5 mass%, Na: 0.01 to 0.5 mass%, Pb: 0.01 to 0.5 mass% The flux-free brazing method for an aluminum material according to claim 1.   The aluminum alloy member contains, as the metal element, Bi: 0.01 to 0.5 mass%, In: 0.01 to 0.5 mass%, Sn: 0.01 to 0.5 mass%, K : 0.01 to 0.5 mass%, Se: 0.01 to 0.5 mass%, Na: 0.01 to 0.5 mass%, Pb: 0.01 to 0.5 mass%, or one or two of them The flux-free brazing method for an aluminum material according to claim 1, comprising the above.   The said aluminum alloy member contains 0.1-0.7 mass% of Mg further, The flux free brazing method of the aluminum material in any one of Claims 1-3 characterized by the above-mentioned.   The brazing material contains the metal element, and as the metal element, Bi: 0.01 to 0.5 mass%, In: 0.01 to 0.5 mass%, Sn: 0.01 to 0.5 mass%, One or two of K: 0.01-0.5 mass%, Se: 0.01-0.5 mass%, Na: 0.01-0.5 mass%, Pb: 0.01-0.5 mass% The flux-free brazing method for an aluminum material according to any one of claims 1 to 4, further comprising seeds or more.   The brazing material contains the metal element, and the metal element contains Bi: 0.01 to 0.5 mass%, In: 0.01 to 0.5 mass%, Sn: 0.01 to 0.5 mass%, K: 0.01-0.5 mass%, Se: 0.01-0.5 mass%, Na: 0.01-0.5 mass%, Pb: 0.01-0.5 mass% The flux-free brazing method for an aluminum material according to any one of claims 1 to 4, comprising one or more of the following.   The brazing is performed such that the thickness of the oxide film on the surface of the joint is 20 nm or less when the actual temperature of the joint is 550 ° C. during the temperature raising process of the brazing. A flux-free brazing method for an aluminum material according to any one of claims 1 to 6.   The brazing is performed so that the thickness of the MgO film on the surface of the joint is 2 nm or less when the actual temperature of the joint is 550 ° C. during the temperature raising process of the brazing. The flux-free brazing method for an aluminum material according to any one of claims 1 to 7.   The flux-free brazing method for an aluminum material according to any one of claims 1 to 8, wherein the non-oxidizing gas atmosphere is an atmosphere having an oxygen concentration of 100 ppm or less. A flux-free brazing that uses an Al alloy brazing material containing 3 to 13 mass% of Si and 0.1 to 5.0 mass% of Mg without using flux in a non-oxidizing gas atmosphere having an oxygen concentration of 100 ppm or less. Attached aluminum alloy member,
One or two metal elements having a melting point of 350 ° C. or lower and a standard free energy of formation (ΔG °) of oxide at 600 ° C. higher than −150 (kg cal / gr mol O 2) in the aluminum alloy member. An aluminum alloy member for flux-free brazing characterized by containing 0.01 to 0.5 mass% of each of the above.   As the metal element, Bi: 0.01 to 0.5 mass%, In: 0.01 to 0.5 mass%, Sn: 0.01 to 0.5 mass%, K: 0.01 to 0.5 mass%, Se : 0.01-0.5 mass%, Na: 0.01-0.5 mass%, Pb: One or more of 0.01-0.5 mass% are contained. 10. An aluminum alloy member for flux-free brazing according to 10.   As said metallic element, Bi: 0.01-0.5mass% is contained, Furthermore, In: 0.01-0.5mass%, Sn: 0.01-0.5mass%, K: 0.01-0 .5 mass%, Se: 0.01 to 0.5 mass%, Na: 0.01 to 0.5 mass%, Pb: 0.01 to 0.5 mass%, containing one or more. The aluminum alloy member for flux-free brazing according to claim 10, characterized in that   The brazing material contains the metal element, and as the metal element, Bi: 0.01 to 0.5 mass%, In: 0.01 to 0.5 mass%, Sn: 0.01 to 0.5 mass%, One or two of K: 0.01-0.5 mass%, Se: 0.01-0.5 mass%, Na: 0.01-0.5 mass%, Pb: 0.01-0.5 mass% The aluminum alloy member for flux-free brazing according to any one of claims 10 to 12, comprising a seed or more.   The brazing material contains the metal element, and the metal element contains Bi: 0.01 to 0.5 mass%, In: 0.01 to 0.5 mass%, Sn: 0.01 to 0.5 mass%, K: 0.01-0.5 mass%, Se: 0.01-0.5 mass%, Na: 0.01-0.5 mass%, Pb: 0.01-0.5 mass% The aluminum alloy member for flux-free brazing according to any one of claims 10 to 12, comprising one or more of the following.   The aluminum alloy member for flux-free brazing according to any one of claims 10 to 14, further comprising Mg: 0.1 to 0.7 mass%.

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