JP2801192B2 - Aluminum alloy and aluminum alloy composite for heat exchanger members - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an aluminum alloy for a heat exchanger member manufactured by brazing and a laminated material using the alloy as a core material, and particularly to an excellent strength. Things. [Prior art] Many conventional heat exchangers, especially heat exchangers for automobiles, such as radiators, heaters, oil coolers, evaporators and condensers for air conditioners, are made of Al alloy, and are assembled into a desired shape and then assembled. It is joined by attaching. Materials for these heat exchangers include Al and Al alloys shown in Table 1. When these Al or Al alloys are used alone, they may be used as extruded multi-hole tubes for heat exchangers for air conditioners, fins or oars for laminated evaporators or oil coolers
There are Al type radiator pipes, etc. In addition, when these Al or Al alloys are used as a joining material, aluminum alloy brazing material as shown in Table 2 is used as a cladding material.
Alternatively, a brazing sheet clad on one or both sides of an Al alloy core material is used. Examples of the use of the brazing sheet include fan materials for heat exchangers for air conditioners, sheet materials for laminated evaporators and oil coolers, radiator tubes, headers or tank materials, and radiator tubes and header materials for cooling water. Alternatively, a material in which a sacrificial anode layer having a lower potential than the core material is provided on the surface of the brazing sheet that comes into contact with the cooling water or the cooling liquid to improve corrosion resistance inside the member through which the cooling liquid flows, thereby preventing through-hole corrosion. It is used. Al alloys are also used in fin materials for heat exchangers for home and commercial air conditioners. [Problems to be Solved by the Invention] In such heat exchangers, recently, there is an increasing demand for thinning of each component for the purpose of weight reduction and cost reduction. And various alloy developments have been attempted. However, members for heat exchangers, especially members manufactured by brazing, have high strength at the time of brazing heated to about 600 ° C. and strength after brazing,
In addition, when flux is used during brazing, there is no reaction with the flux, and after brazing, corrosion resistance is also required. Not. [Means for Solving the Problems] The present invention has been variously studied in view of the above, and as a result, the aluminum alloy and the aluminum alloy composite material for a heat exchanger member having good brazing properties and excellent strength after brazing. Was developed. That is, one of the aluminum alloys of the present invention is Mg 0.01-1 wt.
%, Si 0.01-1.5wt%, Fe0.01-1.0wt%, Ni0.3wt%
Including 5wt% or less, Mn0.01 ~ 2wt%, Cr0.001 ~ 0.5w
t%, Zr0.001-0.5wt%, Hf0.001-1.5wt%, Ti0.001-0.5
wt.%, one or more kinds of elements from the group of 0.0001 to 0.1 wt.% B, and the balance consists of Al and inevitable impurities. Another one of the aluminum alloys of the present invention has a Mg of 0.01 to
Including 1wt%, Si 0.01 ~ 1.5wt%, Fe0.01 ~ 1.0wt%, Ni0.3wt% to 5wt%, Mn0.01 ~ 2wt%, Cr0.001 ~
0.5wt%, Zr0.001 ~ 0.5wt%, Hf0.001 ~ 1.5wt%, Ti0.001
~ 0.5wt%, B 0.0001 ~ 0.1wt%, containing one or more elements from the group, and Zn0.5 ~ 5wt%, In0.005 ~ 0.5w
It is characterized by containing one or more elements from the group of t%, Sn 0.005 to 0.5 wt%, and the balance of Al and unavoidable impurities. The aluminum alloy composite material of the present invention is characterized in that any one of the above-mentioned aluminum alloys is used as a core material, and one or both surfaces of the core material are clad with an aluminum alloy brazing material containing 5 wt% or more of Si. [Operation] In the present invention, the component composition of the Al alloy is limited as described above for the following reasons. The addition of Mg causes solid solution in the matrix and Mg with Si.
₂ The fine precipitates of Si are generated and contribute to the improvement of strength.The reason why the Mg content is limited to 0.01 to 1 wt% is that sufficient strength cannot be obtained with less than 0.01 wt%, and that if it exceeds 1 wt% This is because the brazing property is significantly impaired, and in the extreme case, it becomes impossible to braze. More preferably, the range of 0.02 to 0.6 wt% is good, and in the case of brazing using a flux, 0.02 to 0.
Addition in the range of 3 wt% is desirable. The addition of Si produces fine precipitates of Mg ₂ Si with Mg,
When n is added, it further generates fine Al-Mn-Si-based precipitates and improves the strength, and the Si content is 0.01 to 1.
The reason why the content is limited to 5 wt% is that if the content is less than 0.01 wt%, sufficient strength cannot be obtained, and if the content exceeds 1.5 wt%, there is a high risk of melting at the time of additional heat for brazing. The addition of Fe improves the strength of the material, especially the high-temperature strength, and the content of Fe is limited to 0.01 to 1.0 wt% by 0.01 wt%.
If it is less than 1.0%, sufficient strength cannot be obtained, and if it exceeds 1.0% by weight, coarse Al-Fe-Si-based or Al-Fe-Ni-based intermetallic compounds are generated and the strength is reduced. The addition of Ni produces fine precipitates of Al ₃ Ni, improving the strength of the material at room temperature and high temperature, and also improving the corrosion resistance and fatigue strength. The Ni content exceeds 0.3 wt% to 5 wt% or less. The reason is that if the content is less than 0.3 wt%, these effects are not sufficient, and if it exceeds 5 wt%, the ductility of the material is reduced. Furthermore, Mn 0.01 to 2 wt%, Cr 0.001 to 0.5 wt%, Zr 0.001 to 0.
5wt%, Hf0.001 ~ 1.5wt%, Ti0.001 ~ 0.5wt%, B0.0001 ~
One or two or more elements are added from the group of 0.1 wt%, or Zn 0.5 to 5 wt%, In0.005 to 0.5 wt%, Sn0.00
The first group, that is, Mn, Cr, Zr, Hf, Ti and B, each of which contains one or more elements from the group of 5 to 0.5 wt% is fine and stable crystallization or precipitation. It has the effect of producing a material and making the structure of the material uniform, and consequently contributes to the improvement of the strength of the material, especially high-temperature strength and ductility. Is not sufficient, and if it exceeds the upper limit, a coarse intermetallic compound is produced at the time of casting in the production of the material, and the ductility and toughness of the material are reduced. Although these elements are effective even when added alone, they often have better effects when added in combination. However, since these elements homogenize the structure and refine the structure, when such a composition is used for a fin material or the like, if the structure is too fine, it will be a portion that comes into contact with the brazing material during brazing. Abnormal diffusion of Si in the material into the material results in buckling of the material. Therefore, when the material of the present invention is used for a member in which diffusion of Si is a problem, the addition amount of these elements should be minimized. Further, since the second group, that is, Zn, In and Sn all have the effect of lowering the potential of the material, when the material of the present invention is used as a site requiring a sacrificial effect, it improves pitting corrosion resistance. The respective contents are limited as described above because the effect is not sufficient below the lower limit, and the effect is saturated when it exceeds the upper limit, and there is a possibility that the ductility of the material may be further reduced. These elements may be added alone or in combination of two or more. Next, the Al alloy composite material according to the present invention is a material in which the above Al alloy is used as a core material and a brazing material containing 5 wt% or more of Si is clad on one or both surfaces thereof.
The reason for the above limitation is that if the content is less than 5 wt%, the liquidus temperature is high, so that the brazing material does not sufficiently melt and brazing becomes difficult. For this reason, ordinary brazing filler metals containing 5 to 15 wt% of Si are used.
A small amount of e, Bi, Mg, etc. may be added. The brazing material is preferably clad on one or both sides of the core material in a range of 3 to 30%, more preferably 5 to 15% of the total thickness. If necessary, such a cladding material may be clad in multiple layers. In this case, the alloy of the present invention and the brazing material need not be in contact with each other, but may have one or more layers of alloy between them. The cladding may be performed via a layer. In the case of an Al alloy composite material in which a brazing material is clad on one surface, an Al alloy having a potential lower than that of the core material by 50 mV or more can be clad on the other surface. The reason why the potential of the Al alloy is made to be low is that the Al alloy acts as a sacrificial layer in cathodic protection and protects the core material. Is not obtained. The sacrificial layer is preferably clad in the range of 1 to 20%, more preferably 3 to 20% of the total thickness. Further, when such a laminated material is clad in multiple layers, the core material according to the present invention and the sacrificial layer do not need to be in direct contact with each other, and are at least 50 mV with respect to other core materials directly in contact with the sacrificial layer. What is necessary is just to have a low potential. The above alloys of the present invention and composite materials can be used as materials for any brazing method such as flux brazing, inert atmosphere brazing, and vacuum brazing. Further, these alloys and composite materials can be manufactured by a conventional method. [Examples] Next, the present invention will be described with reference to Examples. Example (1) An Al alloy having the composition shown in Table 3 was melted, continuously cast, the ingot was hot-rolled, then cold-rolled and annealed to produce a sheet material having a thickness of 1 mm. A tensile test piece was processed from the plate material, heated at a temperature of 610 ° C. for 5 minutes assuming brazing conditions, and then subjected to a tensile test. The results are also shown in Table 3.
Further, as a brazing test, as shown in FIG.
The abutting portion by the brazing heating in the reverse T 5% suspension of the flux consisting of preprocessed fluoroaluminate, potassium using a joint test piece was applied after drying N ₂ gas atmosphere butted against the PC Fillets were formed, and the results are shown in Table 3 together with ○ for those with good fillets, and x for those without fillets or non-uniform fillets. In addition, JIS3003,
Similar tests were conducted for JIS3004 and JIS6061, and the results are shown in Table 3. As is clear from Table 3, all the alloys of the present invention have good brazing properties and a tensile strength of 16.2 kgf / mm ² or more, which is equal to or higher than that of the conventional alloy. I understand. On the other hand, the comparative alloy No. 8 having a Mg content exceeding 1 wt% has poor brazing properties, and the comparative alloys No. 7 and No. 10 which do not contain Mg and the comparative alloys No. 9 and No. It can also be seen that the tensile strength was inferior. Example (2) A plate was obtained using the ingot of the alloy No. 3 of the present invention shown in Table 3, and the plate was used as a core in a structure shown in Table 4 and one surface thereof was JIS4045 shown in Table 1. A 1.0mm thick clad alloy plate material brazed with a thickness of 10% of the total thickness and JIS7072 alloy clad on the other surface with a thickness of 10% of the total thickness as a sacrificial layer material The material was manufactured by a conventional method. A 32 mm × 200 mm plate was cut out from the laminated material, processed into a JIS No. 5 tensile test piece, subjected to a tensile test, and the results are shown in Table 4. In addition, after cutting out a 50 mm × 100 mm plate from the above laminated material, seal the JIS4045 alloy surface, perform a 500-hour CASS test to evaluate the corrosion resistance from the JIS7072 alloy surface, measure the pitting depth, The results are shown in Table 4.
Further, as shown in FIG. 2, the above-mentioned composite material is shown in Table 1.
JIS1050 600 suspension flux consisting preprocessed fluoroaluminate, potassium using reverse T joint specimens abutted on the surface of the alloy sheet in the coating was dried N ₂ gas atmosphere
The heat of brazing was applied at 5 ° C. for 5 minutes to evaluate the brazing properties of the fillets, and the results are shown in Table 4. For comparison, the conventional alloy JIS3003 alloy is used as the core material and JIS40
45 alloy is used as brazing material and clad at 10% of the total sheet thickness, and JIS7072 alloy is used as a sacrificial layer skin on the other side.
A 1.0 mm-thick laminated material clad at a thickness of 0% was produced by a conventional method, and the same tests were performed as described above. The results are shown in Table 4. The potential in Table 4 is based on the core material of
5% Na based on saturated calomel electrode for alloy skin
The values measured in a Cl aqueous solution at 25 ° C. are shown. As is clear from Table 4, the laminated material of the present invention is particularly superior in strength and superior in corrosion resistance as compared with the comparative material. [Effects of the Invention] As described above, according to the present invention, an Al alloy and an Al alloy composite material having high strength, excellent brazing properties and corrosion resistance can be obtained.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side view showing a brazing property test of the alloy of the present invention.
The figure is a side view showing a brazing property test of the laminated material of the present invention. 1 JIS BA12PC brazing sheet 2… Alloy 3 of the present invention… Laminated material 4 of the present invention… JIS1050 alloy sheet

────────────────────────────────────────────────── (5) References JP-A-59-85837 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) C22C 21/00

Claims (1)

(57) [Claims] Mg0.01 ~ 1wt%, Si0.01 ~ 1.5wt%, Fe0.01 ~ 1.0wt%,
Contains more than 0.3wt% of Ni and less than 5wt%, and more than 0.01wt% of Mn
%, Cr0.001 ~ 0.5wt%, Zr0.001 ~ 0.5wt%, Hf0.001 ~ 1.5w
For heat exchanger members, characterized by containing one or more elements from the group of t%, Ti0.001 ~ 0.5wt%, B0.0001 ~ 0.1wt%, with the balance being Al and unavoidable impurities. Aluminum alloy. 2. Mg0.01 ~ 1wt%, Si0.01 ~ 1.5wt%, Fe0.01 ~ 1.0wt%,
Contains more than 0.3wt% of Ni and less than 5wt%, and more than 0.01wt% of Mn
%, Cr0.001 ~ 0.5wt%, Zr0.001 ~ 0.5wt%, Hf0.001 ~ 1.5w
An aluminum alloy containing one or more elements from the group of t%, 0.001 to 0.5 wt% of Ti, and 0.0001 to 0.1 wt% of B, and the balance being Al and unavoidable impurities is used as a core material. An aluminum alloy composite material for heat exchanger members, characterized in that one or both surfaces of the above are clad with an aluminum alloy brazing material containing 5 wt% or more of Si. 3. Mg0.01 ~ 1wt%, Si0.01 ~ 1.5wt%, Fe0.01 ~ 1.0wt%,
Contains more than 0.3wt% of Ni and less than 5wt%, and more than 0.01wt% of Mn
%, Cr0.001 ~ 0.5wt%, Zr0.001 ~ 0.5wt%, Hf0.001 ~ 1.5w
t%, Ti 0.001-0.5wt%, B0.0001-0.1wt%, containing one or more elements, Zn0.5-5wt%, I
An aluminum alloy for a heat exchanger member, comprising one or more elements from the group of n 0.005 to 0.5 wt% and Sn 0.005 to 0.5 wt%, the balance being Al and unavoidable impurities. 4. Mg0.01 ~ 1wt%, Si0.01 ~ 1.5wt%, Fe0.01 ~ 1.0wt%,
Contains more than 0.3wt% of Ni and less than 5wt%, and more than 0.01wt% of Mn
%, Cr0.001 ~ 0.5wt%, Zr0.001 ~ 0.5wt%, Hf0.001 ~ 1.5w
t%, Ti 0.001-0.5wt%, B0.0001-0.1wt%, containing one or more elements, Zn0.5-5wt%, I
an aluminum alloy containing one or more elements from the group of n0.005 to 0.5 wt% and Sn0.005 to 0.5 wt%, with the balance being Al and unavoidable impurities as a core material, one side of the core material or An aluminum alloy composite material for heat exchanger members, characterized in that both surfaces are clad with an aluminum alloy brazing material containing 5 wt% or more of Si.