JPH1110310A - Manufacturing method of metal matrix composite material - Google Patents

Abstract

(57) [Problem] To provide a method for manufacturing a metal-based composite material excellent in productivity, in which even when the surface shape of the metal-based composite material is complicated, the surface shape can be easily formed into an arbitrary shape. To provide. SOLUTION: In manufacturing a metal matrix composite material in which a reinforcing material 2 made of ceramic is embedded in a metal matrix, the reinforcing material 2 is arranged in a molding die 1 and a metal is placed in the molding die 1. In the method of pouring and cooling the molten metal 30, the mold 1 is stably present without being decomposed or melted at a temperature lower than the temperature of the molten metal 30. Or, it is formed of a material having easy disintegration.

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 metal matrix composite material in which a reinforcing material made of ceramic is incorporated in a matrix of a metal such as an aluminum alloy, and more particularly to a material for a molding die.

[0002]

2. Description of the Related Art Conventionally, a metal-based composite material is prepared by placing a reinforcing material such as ceramic fiber in a mold, pouring a molten metal into the material, and solidifying the molten metal under pressure. It is done by. The above metal matrix composite material
It has excellent properties such as high strength and high toughness, and is used as various functional parts.

[0003]

However, a material having a high hardness, such as steel or ceramics, has been used for the molding die. Therefore, when the inner surface of the cavity of the molding die is complicated, the processing is difficult. Also, it is difficult to process the surface of the obtained metal matrix composite material. for that reason,
The productivity of metal-based composite materials is low and the cost is high.

Further, when the surface shape of the metal-based composite material is complicated, that is, when the mold surface shape of the mold is complicated, the metal-based composite material cannot be easily removed from the mold.
Therefore, the shape of the metal matrix composite material to be manufactured is also limited. The present invention has been made in view of the above-mentioned conventional problems, and enables the production of a metal-based composite material having excellent productivity, in which even if the surface shape of the metal-based composite material is complicated, the surface shape can be easily formed into an arbitrary shape. It seeks to provide a way.

[0005]

According to the first aspect of the present invention, when manufacturing a metal matrix composite material in which a reinforcing material made of ceramic is incorporated in a metal matrix, the reinforcing material is arranged in a mold. In addition, in the method of pouring the molten metal into the mold and cooling, the mold is stably present without being decomposed and melted at a temperature lower than the temperature of the molten metal, while being easily dissolved in the solvent after casting. A method for producing a metal-based composite material, characterized by being formed of a material having easiness or easiness to collapse.

The most notable point of the present invention is that the mold for molding the metal matrix composite does not decompose or melt below the temperature of the molten metal, and is easily dissolved or collapsed after casting. Is to be made of a material having properties. In the present invention, the ceramic reinforcing material includes ceramic powder, whiskers, fibers and the like.
Further, as the material of the above ceramics, silicon carbide, alumina, zirconia, aluminum nitride, boron carbide,
There are silicon nitride, beryllia, diamond, cubic boron nitride and the like. Examples of the metal include an aluminum alloy, a magnesium alloy, a copper alloy, and a zinc alloy.

Next, the function and effect of the present invention will be described.
That is, according to the present invention, the mold is made of a readily soluble or easily disintegrable material. Therefore, after molding the metal-based composite material, the mold can be easily removed from the metal-based composite material by the solvent. Therefore, even when the mold surface shape is complicated, the metal-based composite material can be easily manufactured, and the productivity is excellent.

Next, as the material of the mold, any one or more of sodium chloride, rock salt, potassium chloride and calcium chloride can be used. In this case, the salt is easily soluble or easily disintegrable in water, an organic solvent, or the like. The material of the molding die may be mixed with ceramics, metal or alloy powder. In this case, the strength is improved, and destruction during handling can be prevented.

These salts can be easily formed into a mold having a desired cavity inner surface, for example, by press-molding the powder with a mold (see the embodiment). In addition, these salts have a high melting temperature and sufficiently withstand the molten metal even when an aluminum alloy or a magnesium alloy is used as the metal. After casting, it can be easily removed by washing with water or blowing high-pressure gas.

Next, it is preferable that the reinforcing material is silicon carbide particles, and the material of the mold is sodium chloride. In this case, in particular, silicon carbide has high thermal conductivity and low thermal expansion, and is suitable for a high-performance composite material.
Sodium chloride has high heat resistance, easy moldability, easy disintegration, and can have the effect of being excellent in productivity.

Further, the metal-based composite material can be used as a heat sink for electronics. In this case, it is possible to easily manufacture a heatsink for an electronic device having a complicated shape capable of efficiently dissipating heat while being in contact with electronic components such as a printed wiring board and a power device. Further, in each of the above inventions, various metal-based composite materials such as a piston for an internal combustion engine can be easily manufactured in addition to the electronic heat sink.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION

Embodiment 1 A method for manufacturing a metal-based composite material according to an embodiment of the present invention will be described with reference to FIGS. This example is shown in Figs.
As shown in FIG. 3, a metal matrix composite material 1 in which a reinforcing material 2 made of ceramics is incorporated in a metal matrix 3
In the production of the metal mold 0 (FIG. 3), the reinforcing material 2 is arranged in the mold 1 and the molten metal 30 is poured into the mold 1 and cooled.

The mold 1 exists stably without being decomposed or melted at a temperature lower than the temperature of the molten metal 30. On the other hand, after casting, the mold 1 is made of a material which is easily soluble or disintegrable in a solvent. It is formed. Further, in the present embodiment, the respective steps in the case of using sodium chloride powder as the material of the molding die 1, silicon carbide powder as the reinforcing material 2, and aluminum alloy as the metal 3 will be described.

(Molding of mold 1 made of sodium chloride) In order to obtain a mold 1 having a mold surface in the shape of the metal-based composite material 10 (FIG. 3B) as a final product, a powder of sodium chloride is formed. In order to solidify the molding die 1, molding is performed at a pressure as high as possible. The pressure during molding is 500kg / c
m ² or more is preferable. After molding, heating can be performed to improve the strength, but it is sufficient to keep the molding as it is.

It is important that the purity of sodium chloride is such that its melting temperature is higher than the melting point of the metal used in high pressure casting, or that it does not melt under the preheating conditions of the reinforcing material. The particle size of the sodium chloride powder can be changed depending on the purpose of controlling the productivity and the strength of the mold, but when smoothing the surface of the product of the metal matrix composite material, 50 to 0.5 μm is applied to the whole or near the surface. It is preferable to use fine powder of

(Preparation for Casting) As shown in FIG. 1, the inside (cavity) of a mold 1 is filled with a reinforcing material 2 made of silicon carbide powder. The particle size and filling amount of the powder can be changed depending on the characteristics of the metal matrix composite material 10 to be manufactured. In particular, when it is desired to increase the filling amount, a mixed powder of fine powder and coarse powder is preferably used. After filling and before casting, the powder can be subjected to filling pressure.

(Casting) As shown in FIG. 2, a mold filled with powder is preheated to about 750.degree. Thereafter, the mold 1 is placed in a mold 15 different from the mold 1 that has been preheated in advance, and a molten aluminum alloy as the molten metal 30 is poured immediately. Next, the pressure punch 16
To solidify and cool the molten aluminum alloy by infiltrating into the gaps between the silicon carbide powders.

(Removal of Metal Matrix Composite Material) The Die 1
The mold 1 is taken out of the mold 5. Next, the mold is immersed in running water to dissolve and remove sodium chloride as a mold material. As a result, as shown in FIG. 3A, the metal matrix composite material 10 and an extra metal 31
Is obtained. Therefore, excess metal 31 adhering to the upper part of the metal matrix composite material 10 is removed by cutting. Thereby, the metal matrix composite material 10 shown in FIG. 3B is obtained.

Embodiment 2 As shown in FIGS. 4 to 6, this embodiment is directed to an example of manufacturing a metal matrix composite material used as an electronic heat sink (FIG. 6). As shown in FIG. 6, the electronic radiator plate 5 has a plate-shaped base 51 to be joined to electronic parts and the like.
And the heat dissipating fins 55 formed integrally therewith. The electronic heat sink 5 has a ceramic reinforcing material 2 made of silicon carbide powder incorporated in a matrix of a metal 3 made of an aluminum alloy.

A specific example of a method for manufacturing the above-described electronic heat sink 5 will be described below. Using a commercially available sodium chloride powder having a purity of 99% or more, pressurizing at 1000 kg / cm ² for 10 seconds, length 50 mm, width 80 mm, depth 5 mm
The mold 4 having the rectangular cavity 40 was manufactured.
The molding die 4 has a diameter of 3 mm at the bottom of the rectangular cavity 40.
It has 50 cylindrical cavities 5 mm in depth and 5 mm in depth.

The molding die 4 was filled with silicon carbide powder mixed at a ratio of 70% by weight of 100 μm powder to 30% by weight of powder having an average particle diameter of 20 μm. Powder is mold 4
Vibration was applied at the time of filling sufficiently to fill the inside.

Next, the mold 4 filled with the silicon carbide powder was preheated at 700 ° C. for about 15 minutes in a nitrogen gas. The mold 4 was placed in a mold that had been preheated to about 300 ° C. (see FIG. 2). Then, the Al-12% S kept at 750 ° C
The i-0.3% Mg alloy was poured and immediately pressurized with a pressure punch to solidify.

After cooling, excess aluminum alloy was removed from the metal matrix composite material, and the sodium chloride mold was washed away with water. The electronic heat sink 5 (FIG. 6) as the obtained metal matrix composite material has the same shape as the mold surface of the sodium chloride mold, and the surface is smooth and can be used without finishing polishing. Was something.

[0024]

According to the present invention, even when the surface shape of a metal-based composite material is complicated, the surface shape can be easily formed into an arbitrary shape, and the production of a metal-based composite material excellent in productivity can be achieved. A method can be provided.

[Brief description of the drawings]

FIG. 1 is an explanatory view showing a state in which a molten metal is poured into a molding die in which a powdery reinforcing material made of ceramics is placed according to a first embodiment.

FIG. 2 is an explanatory diagram showing a state in which the molding die is placed in a mold and is subjected to pressure casting in the first embodiment.

FIG. 3 is an explanatory view of (A) a cast product and (B) a metal-based composite material from which an extra metal portion has been removed in the first embodiment.

FIG. 4 is a plan view of a molding die according to a second embodiment.

FIG. 5 is a sectional view of a molding die according to a second embodiment.

FIG. 6 is an explanatory view of an electronic radiator plate according to a second embodiment.

[Explanation of symbols]

 1. . . Mold, 15. . . Mold, 2. . . 2. reinforcement material; . . Metal, 30. . . 3. molten metal; . . Mold, 5. . . Heat sink for electronics,

 ──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Naohisa Nishino 41-Yokomichi, Nagakute-cho, Aichi-gun, Aichi Prefecture Inside of Toyota Central Research Laboratory Co., Ltd. 41, Yokomichi, Toyota Central Research Laboratory Co., Ltd. (72) Inventor Hiroshi Hojo 41, Yokomichi, Yoji, Nagakute-cho, Aichi-gun, Aichi Prefecture, Japan Toyota Central Research Laboratory Co., Ltd.

Claims (1)

[Claims] In producing a metal matrix composite material in which a reinforcing material made of ceramic is embedded in a metal matrix, the reinforcing material is placed in a mold and a molten metal is poured into the mold. In the method of hot-water cooling, the above-mentioned mold exists stably without decomposing or melting below the temperature of the above-mentioned molten metal, but has good solubility or easy disintegration in solvent after casting A method for producing a metal-based composite material, which is formed of a material.