JPH04200855A - Production of fiber reinforced metal matrix composite - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

Detailed Description of the Invention (Field of Application in Industry -■-) The present invention provides a fiber-reinforced fiber molded product in which molten metal can easily penetrate into a fiber molded product for metal reinforcement, and there is no gas defect in which the fiber and metal are in close contact with each other. This invention relates to a method for manufacturing metal composite materials.

(Prior art and its problems) As a manufacturing method for fiber-reinforced metal composite materials, there is a high-pressure casting method in which a fiber molded body is placed in a mold, molten metal is press-fitted, and the molten metal permeates into the fiber molded body. Are known. In this method, it is necessary to remove the gas inside the fiber molded product and to maintain the shape of the fiber molded product.

Up to now, a method has been proposed in which the gas in the fiber molded body placed in the mold is exhausted, the molten metal is impregnated under reduced pressure, and then solidified under high pressure (Japanese Patent Laid-Open No. 60-626
No. 5). However, with this method, it is difficult to impregnate the molten metal under reduced pressure when the wetting of the molten metal and fibers is poor, or when the fiber volume fraction of the metal composite H material is large.

In addition, the fiber molded body is directly brought into contact with an exhaust means provided in the mold, and the fiber molded body is fixed to the exhaust means by suction, and the molten metal is supplied while blowing tJl of gas inside the fiber molded body, A method of pressure impregnation has been proposed (Japanese Patent Application Laid-open No. 257442/1983). In this method, since the fiber molded body is directly contacted and fixed to the exhaust means, the temperature of the contact portion of the preheated fiber molded body decreases, and therefore it is difficult to uniformly impregnate the molten metal.
This is inconvenient because the fiber molded body is deformed.

(Technical means for solving the problem) The present invention maintains the preheating temperature of the fiber molded body and press-fits the molten metal to infiltrate the molded body while exhausting the gas inside the molded body. Provided is a method for producing a fiber-reinforced metal composite material free of.

The present invention provides that when manufacturing a fiber-reinforced metal composite material by a high-pressure casting method in which molten metal is pressurized into a fiber molded body, an exhaust port for suction and exhaust and a porous body covering the exhaust port are provided in the mold, The fiber molded body with the porous body partially joined is preheated, the porous body of the fiber molded body part and the porous body of the exhaust port provided in the mold are overlapped, and then the molten metal is poured into the mold. A fiber-reinforced metal composite material characterized in that the molten metal is press-fitted into the fiber molded body while the gas inside the fiber molded body is sucked and exhausted through the porous body of the exhaust port part and the porous body of the fiber molded body part. Regarding the manufacturing method.

The fiber molded article used in the present invention is, for example, silicon carbide fiber, carbon fiber, alumina fiber, boron fiber, 5i-T
It can be manufactured using i-C-0 fiber (Tyranno fiber manufactured by Ube Industries, Ltd.: registered trademark) or whiskers.

The metals used for manufacturing the metal composite material of the present invention include:
Examples include aluminum, aluminum alloys, magnesium, and magnesium alloys.

A specific example of the mold used in the high pressure casting method of the present invention is
As shown in the figure. An exhaust port 2 for suction and exhaust is provided on the bottom surface of the mold 1, and is connected to a suction device 3 for exhaust. Also, a porous body 4 for covering the exhaust port inside the mold.
is provided at the exhaust port.

The porous body 4 provided at the exhaust port 2 is a heat-resistant molded body having a large number of small holes that allow gas to pass through easily by suction, but prevent molten metal from passing through. As a specific example of this porous body,
Examples include molded bodies made of oxides such as silica, zirconia and alumina, metals such as iron, nickel and copper, and carbides such as silicon carbide and graphite.

Easily available bricks, metal filters, etc. can also be used directly. Further, a porous body having a desired shape and size can be manufactured by a generally well-known molding method. For example, in the case of an oxide, the oxide powder is molded using an inorganic adhesive such as water glass and then sintered. In the case of metal, for example, as described in JP-A No. 215933,
Porous bodies can be produced by shot blasting metal foam. The volume fraction of the porous body is preferably 30 to 70%, and if the volume fraction is too small, molten metal may pass through it.
Furthermore, since the mechanical strength of the porous body is weak, the porous body is destroyed by the casting pressure. Moreover, if the volume ratio is too large, it will take a long time to suck and exhaust the gas.

The fiber molded body 5 for reinforcing metal has a porous body 6 joined to a part thereof, and the porous body 6 joined to the fiber molded body overlaps the porous body 4 provided at the exhaust port in the mold. Arrange the fiber moldings as shown. The porous body 6 is desirably a heat-resistant molded body having a large number of small pores with good heat retention in order to prevent heat loss in the preheated fiber molded body, and the porous body 6 is preferably a heat-resistant molded body having a large number of small holes with good heat retention. Like the porous body 4, it is manufactured from oxide, metal, carbide, or the like. The volume ratio of the porous body 6 is 10 to
50% is preferable; if the volume fraction is too small, the mechanical strength of the porous body will be weak and the porous body will be destroyed by the casting pressure.

Also, if the volume ratio is too large, the heat retention will decrease,
Therefore, the temperature of the fiber molded article decreases significantly, and furthermore, it takes a long time to suck and exhaust the gas. In order to join the porous body 6 to the fiber molded body, an inorganic adhesive such as colloidal silica or ethyl silicate can be used.

In the present invention, the fiber molded body 5 to which the porous body 6 is bonded
After preheating, the fiber molded body 5 is placed on the porous body 4 provided at the exhaust port 2 in the mold l, and then the molten metal 7 is placed in the mold l.
The movable punch 8 is lowered to a position where it contacts the molten metal 7, and the molten metal 7 is pumped by the movable bonder 8 while the gas inside the fiber molded body is sucked and exhausted through the porous body 4 and the porous body 6 by the exhaust device l-2. 3. Producing a fiber-reinforced metal composite H material by pressurizing and infiltrating the fiber molded body 5 (effects of the invention) According to the present invention, fiber! (The fiber part of the f molded body is directly f
Since it does not come into contact with the porous body provided in the first part, it is possible to prevent a rapid temperature drop in the preheated fiber molded body, and pressurizes the molten metal while sucking and exhausting the gas inside the fiber molded body. Since it is permeated, a uniform fiber-reinforced metal composite material can be produced without deformation of the molded body, even in fibers that are difficult to wet with the molten metal and in fiber composition molded bodies with a large volume fraction.

(Example) Examples are shown below.

Example 1 5iO7 particles with an average particle diameter of about 100 μm were mixed with water glass, hardened with CO2 gas, and then sintered at 800°C.
7. A porous body was produced in the whole mold having the desired shape. The volume fraction of this porous body was 6,096.

A porous body for bonding fiber molded bodies having a volume fraction of 50% was produced in the same manner as described above, except that S i 02 t'fr particles having an average particle diameter of about 200 μm were used.

The fiber molded article is 100 mm x 1.00 mm >< 1100 t manufactured from silicon carbide whiskers.
The volume fraction of this molded product was about 25 to 3096. This molded body and the porous body for joining the fiber molded body were joined using colloidal silica.

On the porous body installed at the exhaust port in the mold, a porous body preheated to 630°C or a bonded fiber molded body is placed so that the porous bodies are in contact with each other, and the temperature is increased to 730°C in the mold. 60 of
6. Supply all the molten metal, lower the movable punch, and when the movable punch comes into contact with the molten metal, turn on the suction device, operate the movable punch with a pressure of 500 kgf/mm2, and allow the molten metal to penetrate into the fiber molded body. Zeta.

The fiber-reinforced metal composite material obtained by coagulation was uniform without any disorder of the fiber molded body or gas defects.

Comparative Example 1 Except for using a porous body or an unbonded fiber molded body,
A fiber-reinforced metal composite material 4'A was produced using the same method as in Example 1.3 The obtained fiber-reinforced metal composite material 4'A had voids remaining in the part of the exhaust gas 11 that was in contact with the porous body. However, the penetration of the molten metal was not sufficient. In addition, cracks in the fiber molded body were also observed.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a pressure casting apparatus during casting according to the present invention. 1... Mold, 2... Exhaust [1, 3... Suction device,
4...Porous material, 5...Fiber! 11; Molded object, 6...
Multi-fL body, 7... Molten metal, 8... Movable punch.

Claims (1)

[Claims] When manufacturing a fiber-reinforced metal composite material by a high-pressure casting method in which molten metal is pressurized into a fiber molded body, an exhaust port for suction and exhaust and a porous body covering the exhaust port are provided in the mold.
The fiber molded body with the porous body partially joined is preheated, the porous body of the fiber molded body part and the porous body of the exhaust port provided in the mold are overlapped, and then the molten metal is poured into the mold. A fiber-reinforced metal composite material characterized in that the molten metal is press-fitted into the fiber molded body while the gas inside the fiber molded body is sucked and exhausted through the porous body of the exhaust port part and the porous body of the fiber molded body part. Production method.