JPH07144267A - Cast in method of aluminum based composite material - Google Patents

Abstract

PURPOSE:To obtain the cast in boundary having high joining property by relatively not lowering a temp. of cast in boundary and improving the deposition between Al based composite material and Al alloy in the production of a cast in product of Al based composite material. CONSTITUTION:In the method to cast in/integrate Al based composite material 1 with Al alloy placed in mold, plural recessed grooves or projecting line or protrusions are arranged on the surface to be cast in of Al based composite material, with using the die, which is split to an insert die and main die 3 in contact with Al based composite material 1, further, the insert die, which is made of a heat conductivity material lower than that of the main die, is kept at the temp. higher than that of the main die, the cast in is executed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a product made of an aluminum alloy which is lightweight and is particularly excellent in heat resistance and wear resistance by casting, and is preferably used for manufacturing a disc rotor for a disc brake of an automobile. it can.

[0002]

2. Description of the Related Art This type of product uses an aluminum-based composite material composed of aluminum or an aluminum alloy and ceramic particles in a portion where heat resistance and wear resistance are required, and other portions. Is made of a conventional aluminum alloy for casting and is introduced in JP-A-4-293705.

A disk rotor can be manufactured by casting this aluminum-based composite material with an aluminum alloy. In this case, it is important to sufficiently improve the bondability of the interface between the casting and the casting. The following various methods are conceivable in order to improve this bondability. That is, the preheating temperature of the aluminum-based composite material before the aluminum-based composite material is placed in the mold is further increased, the molten metal temperature of the cast aluminum alloy is further increased, and the aluminum-based composite material is set in the mold. Measures such as shortening the time until the molten aluminum alloy is poured and applying Ni or Zn plating to the surface of the aluminum-based composite material have been taken, but in any case, quality, cost, working condition restrictions, etc. There was a problem in terms.

[0004]

As a result of various studies in view of the above problems, the present invention improves the heat retention of an aluminum-based composite material, and further improves the shape of the composite material to improve the bondability at the interface between the cast-in and garment. It was made.

That is, the present invention is a method of installing an aluminum-based composite material in a mold and integrating the cast-girth with an aluminum alloy, in which a plurality of grooves or ridges are formed on the surface of the aluminum-based composite material that is to be cast. Or provide multiple protrusions,
Using an insert mold that is in contact with an aluminum-based composite material and a mold that is divided into a main mold, and an insert mold that is made of a member having a lower thermal conductivity than the main mold, and has a temperature higher than that of the main mold. It is characterized by holding and casting.

[0006]

The above-mentioned present invention will be further described. First, the mold part for setting the aluminum-based composite material to be cast is an insert mold separate from the main mold, and the material of the insert mold has lower thermal conductivity than the material of the main mold. And
A heater is installed in this insert mold to keep the temperature of the insert mold higher than that of the main mold.

Next, an aluminum-based composite material, which has been formed into a predetermined shape as described below, is preheated outside the mold, set in the mold having the above structure, and molten aluminum alloy is poured into the mold. And cast around with the aluminum alloy.

By providing a plurality of uneven lines or projections on the surface of the aluminum-based composite material to be cast at this time, the contact surface area between the molten aluminum alloy and the aluminum-based composite material is increased, so that the temperature of the aluminum-based composite material is increased. It rapidly rises and solidifies in a high temperature state so that the weldability is improved. Therefore, the joint strength at the interface between the cast metal and the molten metal after solidification of the molten metal is remarkably improved as compared with the conventional case.

After casting, the product is commercialized through processes such as removal of unnecessary parts and cutting. The product obtained by the method of the present invention has a relatively low temperature at the interface between the cast and sill and has a large bonding area, so that a good bonding interface can be obtained.

[0010]

EXAMPLE An example in which the present invention is applied to the manufacture of an aluminum-based composite material disk rotor having a structure in which the sliding surface portion is formed of an aluminum-based composite material and the other portion is cast in an aluminum alloy is shown.

A ring-shaped aluminum-based composite material made of an aluminum alloy containing 20% silicon carbide particles was molded as a sliding surface shape product. The surface of the composite material on the interface between casting and burrs (anti-sliding surface side) has a shape in which a plurality of recessed grooves (A) are penetrated in the radial direction as shown in FIG. 1, or as shown in FIG. A plurality of protrusions (B) were erected. Such a shape can be easily obtained by forming reverse concavities and convexities on a die for molding the sliding surface shaped article.

Next, as shown in FIG. 3, a portion for setting the sliding surface of the sliding surface shape product (1) of the disk rotor casting mold is a stainless insert mold (2) (2 ').
The other main mold (3) was manufactured by SKD61.
Eight rod-shaped heaters (4) are installed in the insert molds (2) and (2 '), respectively.
(2 ') was used for heating and heat retention. The main mold (3) is composed of a fixed mold (5) and a movable mold (6) as in the conventional case, and the movable mold (6) is movable by a pressure cylinder (7). (8)
Indicates a support plate. In this case, in order to prevent the heat of the insert mold from escaping to the main mold, a heat insulating material such as an asbestos sheet may be inserted between the insert mold and the main mold.

The temperature of the main die of the die having the above structure is set to about 200.
℃, the temperature of the insert mold is about 400 ℃, after the above-mentioned sliding surface shape product (1) preheated to 500 ℃ outside the mold is set in the mold, molten aluminum alloy at 720 ℃ (9) Was poured and the sliding surface shape product (1) was cast to obtain an aluminum-based composite disk rotor. In the figure, (10) shows a molten metal sleeve, and (11) shows a pressure punch for pouring the molten aluminum alloy into the mold under pressure.

At the joining interface between the aluminum-based composite material and the aluminum alloy of the obtained disk rotor, both were welded together without any gap as shown in FIG. On the other hand, a sliding surface shape product having a flat surface on the interface between the casting and the casting of the composite material is shown in FIG.
In a disc rotor that is cast from an aluminum alloy without operating the heater in the insert mold of the above, the joining interface between the two can only be obtained by those that are not in close contact with each other or are partially welded. It was

When the disk rotor obtained according to the present invention is mounted on an automobile and used, the shearing force acting in the rotation direction of the rotor is applied not only to the interface between the aluminum alloy and the aluminum-based composite material but also to the mutual mother material. The strength of the rotor is greatly improved as compared with a conventional rotor having a flat interface.

[0016]

EFFECTS OF THE INVENTION According to the present invention, the following effects can be obtained in the production of cast-in-mold products of aluminum-based composite materials. Since the temperature at the interface between the cast metal and the aluminum-based composite material and the aluminum alloy is not relatively lowered, the interface between the cast metal and the cast metal having the excellent bondability can be obtained. Since the joint strength at the interface of the cast metal is significantly improved, it is most suitable for manufacturing a lightweight disc rotor using an aluminum-based composite material for the sliding surface portion. Since it is not necessary to raise the temperature of the cast aluminum alloy melt to a particularly high temperature, there is no concern about internal defects due to gas absorption due to high temperature melting and deterioration of the characteristics of the cast product. Since it is not necessary to raise the preheating temperature of the aluminum-based composite material more than necessary, time and energy for preheating can be saved. Since the time from setting the aluminum-based composite material in the mold to pouring the aluminum alloy can be slightly increased, restrictions on working conditions are relaxed. Since it is not necessary to perform surface treatment or the like on the aluminum-based composite material, the cost is reduced.

[Brief description of drawings]

1A and 1B show a shape of an aluminum-based composite material used in an embodiment of the present invention, FIG. 1A is a partial plan view, and FIG. 1B is a view on arrow M of FIG.

2A and 2B also show other shapes, FIG. 2A is a partial plan view, and FIG. 2B is a view on arrow N of FIG.

FIG. 3 is an explanatory view showing an example of a mold for carrying out the present invention.

FIG. 4 is a photograph of a metallographic structure showing an interface between a cast metal and an aluminum-based composite material according to the method of the present invention and an aluminum alloy.

[Explanation of symbols]

 1 Sliding surface shape product 2, 2'Insert mold 3 Main mold 4 Bar heater 5 Fixed type 6 Movable type 7 Pressurizing cylinder 8 Support plate 9 Aluminum alloy melt 10 Molten metal sleeve 11 Press punch

Claims (1)

[Claims] 1. A method of placing an aluminum-based composite material in a mold and integrating cast aluminum with an aluminum alloy, the method comprising: The main mold is an insert mold that is provided with protrusions and uses an insert mold that comes into contact with an aluminum-based composite material and a mold that is divided into a main mold, and that is made of a member having lower thermal conductivity than the main mold. A method of casting a cast aluminum-based composite material using an aluminum alloy, which is characterized in that the casting is carried out at a temperature higher than that of the casting.