JP3472605B2 - Extruded aluminum alloy for brazing - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an extruded aluminum alloy for brazing used in a union of a heat exchanger. 2. Description of the Related Art Extruded aluminum alloys for brazing, which are well known, include A7N01 alloy and 7
Although there is a 003 alloy, the extrudability and corrosion resistance of these No. 7000 series alloys are inferior to 6000 series alloys such as A6063 and 6061. On the other hand, even in such a 6000 series alloy,
6061 alloy has a solidus temperature of 582 ° C and Al-10wt%
Since it is close to the melting point of the Si brazing material, there is a disadvantage that the base material is partially melted during brazing. Also, 6063
Although the alloy can be brazed, there is a drawback that when the alloy is heated for a short time such as baking after painting, improvement in strength can hardly be expected. The present invention has been made in view of such technical background, and is capable of being brazed, has excellent extrudability and corrosion resistance, and does not cause dissolution during brazing, and furthermore, has the following features. When heating for a short time after attaching,
An object of the present invention is to provide an extruded aluminum alloy for brazing in which improvement in strength can be expected. [0005] In order to achieve the above object, the present invention is based on an Al-Mg-Si alloy which is basically an extruded brazing alloy having excellent extrudability and corrosion resistance. By adding a predetermined amount of Cu to this,
The above object has been achieved. [0006] More specifically, the present invention relates to a method for producing Mg: 0.1.
5 to 0.8 wt%, Si: 0.3 to 0.6 wt%, Cu:
0.2 to 0.7 wt% , Ti: 0.01 to 0.1 wt% , or Mn: 0.01 to 0.1 wt% . Including 2wt%
Yes, and it is an gist extruded aluminum alloy for brazing, characterized in that the balance aluminum and inevitable impurities. In the above, Mg and Si are elements that impart excellent strength, brazing property, extrudability, and corrosion resistance. If Mg is less than 0.5 wt% and Si is less than 0.3 wt%, brazing is performed. If heating is performed for a short time later, the effect of improving strength cannot be obtained. On the other hand, if Mg exceeds 0.8 wt%, the brazing property deteriorates, and if Si exceeds 0.6 wt%, the solidus temperature of the alloy becomes 605 ° C. or less, and there is a risk of melting during brazing. . Therefore, Mg is 0.5 to 0.8 wt.
% And Si must be specified in the range of 0.3 to 0.6 wt%. A particularly preferred content is Mg:
0.6 to 0.7 wt%, Si: 0.4 to 0.5 wt%. [0008] Cu is an element that contributes to an improvement in the strength of the alloy when a short-time heating such as baking is applied after brazing. However, if the content is less than 0.2 wt%, the effect is poor. On the other hand, if it exceeds 0.7 wt%, the solidus temperature of the alloy will be 605 ° C. or less, and there will be a risk of melting during brazing. Therefore, Cu must be specified at 0.2 to 0.7 wt%. Particularly preferably 0.3 to
0.5wt% is good. [0009] Ti is used to improve the strength by refining the alloy structure.
It contributes, but the effect is less than 0.01wt%
Poor. Conversely, even if it exceeds 0.1 wt%, the above effects are exceptional
No significant increase can be expected, resulting in economic waste. Especially good
The preferred content is 0.03-0.06 wt%. [0010] Mn is an optional additive element, although Ru der contributes to strength improvement by refining the alloy structure, 0.01 w t
%, The effect is poor. Conversely, if the content exceeds 0.2% by weight , no particular increase in the effect can be expected, resulting in economic waste. Particularly preferred free Yuryou when containing M n
Is from 0.05 to 0.15% by weight. The alloy according to the present invention is extruded and used for a joining member for brazing. Extrusion conditions are not particularly limited, and may be performed according to a conventional method. EXAMPLES (Strength test after short-time heating) Aluminum alloys having various compositions shown in Table 1 were prepared and melted, and then cast into billets having a diameter of 3 inches and a length of 150 mm. Next, these billets were heated at 530 ° C. for 10 hours and then air-cooled to carry out soaking. Next, each billet is heated to 450 ° C., and as shown in FIG. 1, the height H is 40 mm, the width W is 20 mm,
It was extruded into an extruded profile (1) having an L-shaped cross section with a thickness t of 1.0 mm. After extrusion, each extruded material (1) was added at 530 ° C. × 1
After carrying out the encapsulation treatment for a long time, it was water-cooled, and further, each extruded material was subjected to a short-time aging treatment at 180 ° C. × 0.5 hour. In the above process, the embedding treatment was equivalent to the heat applied by brazing, and the short-term aging treatment was equivalent to short-time heating after brazing. Then, a tensile test was performed to measure the proof stress. Table 1 shows the results. (Brazing test) As shown in FIG. 2, two sheets of each extruded material obtained by the above-mentioned extrusion had a thickness of 1 with KF-AlF ₃ eutectic flux adhered to both surfaces.
mm A4045 alloy material (2) was sandwiched in the middle and vertically overlapped with each other, and heated and brazed at 600 ° C. for 3 minutes in an N ₂ atmosphere. Then, the brazed portion of the brazed product was visually observed, and a differential thermal analysis was performed to determine a solidus temperature of each extruded material (1). Table 1 shows the results. [Table 1] As can be seen from the results in Table 1, the products of the present invention have excellent brazing properties and a solidus temperature of 6
It is as high as 05 ° C or higher, so there is no danger of melting when brazing is applied, and the proof stress after short-time aging treatment, which is equivalent to short-time heating after brazing, is all as large as 100 N / mm ² or more. Was obtained. According to the present invention, a predetermined amount of M
Since it contains g, Si, Cu , and Ti , it is not only brazable but also excellent in extrudability and corrosion resistance, and has a high solidus temperature to prevent dissolution during brazing. . In addition, when heating is performed for a short time, such as baking, after brazing, an improvement in strength can be expected, and a brazed product excellent in strength can be provided.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of an extruded material used in an embodiment of the present invention. FIG. 2 is a cross-sectional view of a test piece in a brazing test performed in an example of the present invention. [Description of Signs] 1. Extruded material (extruded aluminum alloy)

Claims (1)

(57) [Claims 1] Mg: 0.5-0.8 wt%, Si:
0.3-0.6 wt%, Cu: 0.2-0.7 wt%,
Ti: An extruded aluminum alloy for brazing containing 0.01 to 0.1 wt%, the balance being aluminum and unavoidable impurities.