JP2907566B2 - Method for producing Al-Zn-Si alloy material - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing an Al--Zn--Si alloy used for a low-temperature brazing material, and particularly to an Al--Z suitable for obtaining the alloy as a plate or a strip.
The present invention relates to a method for manufacturing an n-Si alloy material.

[0002]

2. Description of the Related Art Recently, when brazing aluminum and stainless steel, or when brazing a joining member including an aluminum alloy casting, die casting, or the like, Al-Zn-Si is used.
Attempts have been made to braze using a low-temperature brazing material made of a system alloy.

[0003] Al-
Since the Zn-Si based alloy material has low elongation at high temperatures, in the case of manufacturing a plate or a strip in particular, conventionally, forging is performed after casting, and then rolling is performed.

[0004]

However, in the above manufacturing method, for example, as the amount of Si increases, forging,
There is a disadvantage that cracks occur during rolling and the like. In addition, there is also a disadvantage that productivity is low because it is difficult to process from a very large ingot.

SUMMARY OF THE INVENTION The present invention has been made to solve such a drawback, and it is an object of the present invention to provide an Al-Zn- alloy which can efficiently obtain a plate or a strip without cracks or the like.
The purpose is to produce and provide Si-based alloy materials.

[0006]

As a result of various experiments and studies, the inventor has found that the above object can be achieved by performing extrusion at a relatively low temperature after casting, and has completed the present invention. .

That is, the method for producing an Al—Zn—Si alloy material according to the present invention is as follows: Zn: 30 to 70 wt%;
An alloy billet containing 1.0 to 10 wt% and Be: 0.1 wt% or less, the balance being aluminum and unavoidable impurities is used, and the billet is extruded at a temperature of 250 to 350 ° C. .

First, in the aluminum alloy to be manufactured according to the present invention, Zn (zinc) is an element effective for lowering the melting point of the alloy, and thus makes the alloy usable as a low-temperature brazing material. However, the alloy is 30wt%
If it is less than 70% by weight, the above effects are poor. Conversely, if it exceeds 70% by weight, the workability deteriorates and extrusion by the present invention becomes difficult. A particularly preferred Zn content is 35 to 65 wt%.

[0009] Si (silicon) also serves to lower the melting point of the alloy and increase the fluidity thereof to improve the function as a low-temperature brazing material or the like. However, its content is 1.
If the amount is less than 0% by weight, these effects are poor. On the other hand, if it exceeds 10% by weight, extrusion becomes difficult. A particularly preferred content of Si is 1.0 to 3.0 wt%.

[0010] Be (beryllium) contributes to the improvement of the mechanical properties such as strength and elongation of the alloy without impairing the low melting point effect of Zn and Si. As a result, when the alloy is used as a brazing material, This has the effect of improving the mechanical properties of the brazed joint (fillet) after brazing. However, if the content exceeds 0.1 wt%, the effect is saturated and economic waste is caused. Therefore, the content must be 0.1 wt% or less. A particularly preferred content of Be is 0.005 to 0.015 wt%.

Next, the manufacturing process will be described. In the present invention, after the alloy billet having the above composition is melt-cast,
It is characterized in that it is extruded into a plate or a strip at a relatively low billet temperature of 250 to 350 ° C. Here, the conditions of melting and casting are not particularly limited and may be performed according to a conventional method. One example is as follows. That is, the melting temperature is set to 850 to 950 ° C. and 8
The temperature is maintained at 50 to 950 ° C. for 40 to 80 minutes, the Zn mass is added, and the temperature is adjusted to 700 to 740 ° C. after stirring. The Al-2.5 wt% Be mass is added within this temperature range, and then the molten metal is treated by bubbling. And casting.

In the extrusion performed after casting, the billet temperature is limited to 250 to 350 ° C. because the extrusion itself becomes difficult at a temperature lower than 250 ° C., and when the temperature exceeds 350 ° C., the Al—Zn— This is because eutectic melting of the (Si) system occurs and grain boundary cracks occur due to the pushing force. Therefore, by performing extrusion in the billet temperature range of 250 to 350 ° C., a plate-like extruded material can be obtained without cracking or the like. Other extrusion conditions are not particularly limited in the present invention, but preferably the pressing ratio is 15 to 50, the die temperature is 300 to 350 ° C, the container temperature is 300 to 350 ° C,
The use of a ram speed of 2 to 6 mm / sec is preferable in that a good extruded material can be manufactured by further suppressing the risk of cracking and the like.

After completion of the extrusion step, if necessary, 0.1 to
Rolling may be performed at a rolling reduction of about 1.0 mm / 1 pass to form a thin sheet. Such rolling should be performed in a hot state of 250 to 350 ° C. while still hot immediately after extrusion.
This is preferable in that the extrusion step and the rolling step can be continuously performed to increase the efficiency. Here, the rolling temperature is set to 25
The reason why it is preferable to define the temperature at 0 to 350 ° C. is 250 ° C.
This is because plastic working may be difficult in the following.
If the temperature exceeds 350 ° C., eutectic melting of an Al—Zn— (Si) -based alloy may occur, which may cause grain boundary cracking.

[0014]

Next, an embodiment of the present invention will be described.

[0015]

[Table 1]

Al-Z of each composition of A to D shown in Table 1 above
An n-Si alloy billet was produced by melting and casting.
Melting and casting were performed according to the following procedure. That is, after adding and dissolving Si in Al dissolution (900 ° C.) and keeping it for 30 minutes, Zn was added to adjust the temperature to 720 ° C., and further an Al-Be lump was added. Next, after performing the molten metal treatment,
It was cast into billets at 05 ° C.

Next, each billet was heated to the billet temperature shown in Table 2 and extruded into a plate having a width of 50 mm and a thickness of 5 mm. Extrusion was performed at both container and die temperatures of 30 ° C.
The test was performed under the conditions of 0 ° C., a ram speed of 6 mm / sec, and a pressing ratio of 30.

Next, with respect to Samples Nos. 2 and 4, hot rolling was performed immediately after extrusion to a thickness of 0.2 mm at a temperature of 300 ° C. and a rolling reduction of about 0.5 mm / 1 pass.

Inspection of each of the sheet materials obtained as described above for defects such as cracks revealed that none was recognized. In addition, about sample No.5, since the billet temperature was too high, favorable extrusion could not be performed. Sample N
For o1 to 4, mechanical properties at room temperature were also investigated. The results are shown in Table 2 below.

[0020]

[Table 2]

From the above results, it was confirmed that the Al—Zn—Si alloy plate produced according to the present invention had no cracks and good mechanical properties.

[0022]

According to the present invention, Zn: 30 to
70 wt%, Si: 1.0 to 10 wt%, Be: 0.1 wt%
Using an alloy billet containing the following and the balance of aluminum and unavoidable impurities, the temperature of the billet is 250 to
It is characterized by being extruded at a temperature set to 350 ° C. Therefore, the conventional manufacturing method by forging and rolling is unnecessary, and the Al—Zn—Si alloy material can be easily formed into a plate or a strip without cracking or the like. Can be manufactured. In addition, since the extrusion method is adopted, such an Al-Zn-Si alloy material can be manufactured continuously, and the production efficiency can be increased, and it can sufficiently cope with industrial production as a low-temperature brazing material or the like. Can be. Further, when hot rolling is performed at a temperature of 250 to 350 ° C. immediately after extrusion, the extrusion step and the rolling step can be performed continuously, and a thinner thin plate can be efficiently produced.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ Identification symbol FI C22C 21/10 C22C 21/10 C22F 1/053 C22F 1/053 (56) References JP-A-49-11748 (JP, A) JP-A-3-230889 (JP, A) JP-A-51-10113 (JP, A) JP-A-4-333548 (JP, A) JP-A-4-501536 (JP, A) (58) Fields investigated (Int.Cl. ⁶ , DB name) B23K 35/40 340 B21B 3/00 B21C 23/00 B23K 35/28 310 C22C 18/04 C22C 21/10 C22F 1/053

Claims (2)

(57) [Claims] 1. Zn: 30-70 wt%, Si: 1.0-
Using an alloy billet containing 10 wt% and Be: 0.1 wt% or less, the balance being aluminum and unavoidable impurities,
A method for producing an Al-Zn-Si alloy material, wherein the billet is extruded with the temperature set at 250 to 350C. 2. The method for producing an Al—Zn—Si alloy material according to claim 1, wherein hot rolling is performed at a temperature of 250 to 350 ° C. immediately after the extrusion.