JP2009220144A - Aluminum member internal chill method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an aluminum member internal chill method which is suitable for recycling by the formation of a diffusion layer which does not comprise zinc as impurities in the internal chill of an aluminum member. <P>SOLUTION: When, as an aluminum member, e.g., an aluminum alloy cup 11 is subjected to internal chill with an aluminum alloy, so as to produce an aluminum member internally chilled product, the aluminum member internal chill method comprising: a stage where the aluminum alloy cup is immersed into a molten metal 13 for aluminum immersion (with a melting point of 525°C) comprising, by weight, 26 to 30% copper and 5 to 6% silicon in aluminum, so as to form a diffusion layer by the aluminum alloy molten metal on the surface; and an internal chill stage where the aluminum member in which the diffusion layer is formed by the aluminum alloy molten metal on the surface is set in a mold, so as to cast the same by an aluminum alloy molten metal 17. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an aluminum member casting method in which an aluminum member is cast with an aluminum alloy.

In the case of an aluminum member cast made of aluminum material (for example, an aluminum pipe or aluminum bar made of wrought material), the surface of the aluminum member is not treated or an oxide film is machined. After removing the target chemically and chemically, it is cast.
In the case of the gravity casting method or the low pressure casting method, the temperature at which the molten metal for casting is in contact with the aluminum member is generally 650 ° C to 700 ° C. The melting point of the aluminum wrought material is about 650 ° C. Furthermore, the aluminum wrought material has a feature that the solid-liquid coexistence region is narrow because there are few alloy elements.
For this reason, for example, when casting an aluminum pipe, the aluminum member surface does not melt unless the aluminum member is heated to the melting point. There is a problem that sufficient mechanical strength cannot be obtained.
On the other hand, when the aluminum member is heated to a temperature higher than the melting point, the aluminum wrought material has a small alloy element, so the solid-liquid coexistence area is narrow. .

In order to solve the problem, Patent Document 1 discloses a method of forming a plating layer made of solder or brazing material for aluminum on the surface of an aluminum member.
In Patent Document 2, the surface of an aluminum member is covered with a flux-containing aluminum alloy brazing material containing a brazing filler metal component and a flux component, and a molten aluminum casting material is poured into the mold to cast the aluminum member. Is disclosed.
In any case, the coating layer is formed on the surface of the aluminum member at a relatively low temperature by containing zinc having a low melting point.

Japanese Patent Laid-Open No. 7-290226 JP-A-6-304740

However, the invention disclosed in Patent Document 1 or Patent Document 2 has the following problems.
For example, when an aluminum pipe is cast when an automobile engine cylinder is made of aluminum, in the techniques of Patent Document 1 and Patent Document 2, the solder material or the brazing material contains zinc in order to lower the melting point. is doing.
When recycling the aluminum by melting the cylinder by recycling, there was a problem if zinc contained. That is, since a general aluminum alloy contains copper and silicon, there is no problem even if these elements are contained. However, zinc is an impurity, and treatment for reducing the zinc content is performed. There is a problem that it is necessary and costly to recycle.

  An object of the present invention is to solve the above-mentioned problems, and an object thereof is to provide an aluminum member casting method suitable for recycling.

In order to achieve the above object, the aluminum member casting method of the present invention has the following configuration.
(1) In an aluminum member casting method for casting an aluminum member with an aluminum alloy, a dipping step of immersing the aluminum member in an aluminum alloy molten metal containing 26 to 30% by weight of copper and 5 to 6% by weight of silicon in aluminum And a casting step of casting the soaked aluminum member with an aluminum material.

Next, the operation and effect of the aluminum member casting method of the present invention having the above-described configuration will be described.
According to the aluminum member casting method of the present invention, it has a step of immersing in aluminum melt containing 26 to 30% by weight of copper and 5 to 6% by weight of silicon before casting with an aluminum material. . The melting point of the molten aluminum alloy is about 525 ° C. By immersing the aluminum member in the molten aluminum alloy, a diffusion layer can be formed on the surface of the aluminum member. The melting point of the aluminum member is 650 ° C., and the aluminum member does not melt.

Next, an aluminum member having a diffusion layer formed of molten aluminum alloy on the surface by dipping is set in a mold, and casting is performed with an aluminum material. At the time of casting, the temperature at which the molten aluminum alloy comes into contact with the aluminum member is set to 550 ° C. to 650 ° C., but the melting point of the aluminum alloy forming the diffusion layer is 525 ° C. Therefore, the aluminum member surface, the diffusion layer, and the aluminum material are It can be sufficiently metallic.
Furthermore, when recycling a cast product, the conventional cast product contains zinc, which is an impurity, whereas the aluminum component cast method of the present invention is a component of a normal aluminum alloy. Since it contains only aluminum, copper, and silicon, it can be recycled as it is, so there is no extra effort or cost.

Hereinafter, an embodiment in which an aluminum member casting method according to the present invention is embodied will be described in detail with reference to the drawings.
FIG. 1 shows a diagram of the dipping process. In the immersion container 12, a molten aluminum alloy that contains 26-30 wt% copper (27 wt% in this embodiment) and 5-6 wt% silicon (5 wt% in this embodiment) in aluminum. 13 is stored. A heater 14 is attached to the immersion container 12, and the molten aluminum alloy immersion metal 13 (melting point 525 ° C.) is heated to about 570 ° C.
FIG. 2 shows a cross-sectional view of an aluminum alloy cup 11 that is an aluminum member. The material of the aluminum alloy cup 13 is an aluminum wrought material, 6063. The outer diameter is 20 mm, the length is 100 mm, and the wall thickness is 2 mm.

As shown in FIG. 1, an aluminum alloy cup 11 is dipped for 20 seconds in a molten aluminum alloy dipping bath 13 to about 2/3 of the length. After 20 seconds, the aluminum alloy cup 11 is pulled out from the molten aluminum alloy dipping bath 13. As a result, as shown in FIG. 3, an aluminum immersion layer 15 having a thickness of 1 to 2 mm is formed on the outer peripheral surface of the aluminum alloy cup 11. The aluminum immersion layer 15 is a diffusion layer formed on the surface of the aluminum alloy cup 11.
Next, the aluminum alloy cup 11 on which the aluminum immersion layer 15 is formed is set in the lower mold 16 b of the green sand mold 16. Then, the upper mold 16a is mounted on the lower mold 16b. Then, the molten aluminum alloy 17 is injected into the casting space in the green sand mold 16 through the casting port 18. The material of the molten aluminum alloy 17 is AC4C. Aluminum contains about 7% by weight of silicon, and is a material generally used for aluminum casting. The temperature of the molten aluminum alloy 17 to be injected is controlled to be 680 ° C.

Thereby, the aluminum immersion layer 15 formed on the surface of the aluminum alloy cup 11 and the aluminum alloy molten metal 17 are alloyed, and the surface of the aluminum alloy cup 11 and the molten aluminum alloy 17 are finally cast. It is cast in a metallic state.
Here, when the aluminum alloy cup 11 is immersed in the molten aluminum melt 13, the components of the molten aluminum 13 are 26-30 wt% copper (27 wt% in this embodiment) in the aluminum, silicon 5 Since it is ˜6% by weight (in this example, 5% by weight), the temperature of the molten aluminum for immersing aluminum 13 can be lowered to 570 ° C. compared to 650 ° C., which is the melting point of the aluminum wrought material. The aluminum immersion layer 15 can be formed on the surface without adverse effects such as making a hole in the aluminum alloy cup 11 that is a wrought material.
Furthermore, when the aluminum alloy cup 11 with the aluminum immersion layer 15 formed thereon is cast with the molten aluminum alloy 17 at 680 ° C., the aluminum immersion layer 15 (melting point 525 ° C.) is melted, and the surface of the aluminum alloy cup 11 is The layer and the molten aluminum alloy 17 are strongly bonded metallically.

As described above in detail, according to the aluminum member casting method of the present embodiment, the aluminum alloy cup 11 is a molten aluminum dip containing 26-30 wt% copper and 5-6 wt% silicon in aluminum. 13 (melting point: 525 ° C.) and a casting step in which the aluminum alloy cup 11 is cast with the molten aluminum alloy 17, so that the aluminum alloy cup 13 is immersed in the molten aluminum for immersing aluminum 13. A diffusion layer can be formed on the surface of the member (aluminum alloy cup 11). Then, when the aluminum alloy cup 11 having a diffusion layer formed of molten aluminum alloy formed on the surface by dipping is set in a mold and casting is performed with an aluminum material, the molten aluminum alloy 17 becomes an aluminum member (aluminum alloy cup 11). Although the contact temperature is 550 ° C. to 650 ° C., since the melting point of the aluminum alloy forming the diffusion layer is 525 ° C., the surface of the aluminum member, the diffusion layer, and the aluminum material can be sufficiently bonded metallically.
Furthermore, when recycling a cast product, the conventional cast product contains zinc, which is an impurity, whereas the aluminum component cast method of the present invention is a component of a normal aluminum alloy. Since it contains only aluminum, copper, and silicon, it can be recycled as it is, so there is no extra effort or cost.

In addition, this invention is not limited to the said embodiment, A part of structure can also be changed suitably and implemented in the range which does not deviate from the meaning of invention.
For example, in this embodiment, a sand mold is used as a casting method, but aluminum die casting may be used.

It is sectional drawing which shows the state which immersed the aluminum alloy cup 11 in the molten metal 13 for aluminum immersion. 2 is a cross-sectional view showing the shape of an aluminum alloy cup 11. FIG. It is sectional drawing of the aluminum alloy cup 11 in which the aluminum immersion layer 15 was formed. It is sectional drawing which shows the process of casting the aluminum alloy cup 11 in which the immersion layer 15 was formed with the aluminum alloy molten metal 17. FIG.

Explanation of symbols

11 Aluminum Alloy Cup 13 Molten Aluminum 15 Aluminum Dipped Layer 17 Aluminum Alloy Molten

Claims (1)

In an aluminum member casting method in which an aluminum member is cast with an aluminum alloy,
A dipping step of dipping the aluminum member in an aluminum alloy melt containing 26 to 30 wt% copper and 5 to 6 wt% silicon in aluminum;
An aluminum member casting method characterized by comprising a casting step of casting the immersed aluminum member with an aluminum material.

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