JPH02268962A - Production of fiber reinforced composite material - Google Patents

Abstract

PURPOSE:To obtain the crack-free molding by laminating and depositing a porous refractory molding on a fiber molding, preheating this fiber molding, then putting the molding into a die, injecting a light alloy into the die and molding the alloy under pressurization, then executing a heat treatment and machining away the unnecessary part of the composite part and light alloy. CONSTITUTION:The fiber molding 20 is a circular cylindrical body constituted of ceramics, etc., and has a gap. The porous refractory molding 22 consisting of alumina, etc., is laminated and deposited on one side face and outer side face of the molding 20. The molding 20 is heated together with the molding 22 to a prescribed temp. by an electric heater, etc. The preheated molding 20 is inserted into the die 13 in such a manner that the porous refractory molding 22 in the outside part comes into contact with the inside wall of the die 13 and the surface not mounted with the molding 22 is positioned upward. The light metal 12 in a molten metal state is poured into this die 13 and is pressurized by a pressurizing punch 15 to impregnate the light alloy 12 into the molding 20 and the molding 22, by which the composite is formed. The piston 10 is removed from the die 13 and the light alloy 12 and composite part 20' are removed after the heat treatment, by which the piston is formed. The molding having no cracks between the fiber reinforced composite part and the light alloy is obtd. in this way.

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial Field of Application) The present invention relates to a method for manufacturing a fiber-reinforced composite member, and particularly to a method for producing a composite part of a fiber-reinforced molded body and a cast metal without causing cracks. The present invention relates to a method for manufacturing a fiber-reinforced composite member.

(Prior art and problems to be solved by the invention) 7.Recently, ceramics (S i c, Si 3N4 ° Al2O3,
Fiber-reinforced composite members are being developed by combining a metal or alloy such as aluminum as a matrix metal with a fiber-reinforced molded body composed of whiskers, particles, short fibers, and long fibers such as 20.5Ti02, carbon). .

For example, when this fiber-reinforced composite member is applied to a piston, the head part has high mechanical strength (
It is formed of a fiber-reinforced molded body 11 that is not abrasive, and the skirt portion is formed of a metal or alloy 12 that is a base material and has high mechanical strength.

In order to combine the fiber-reinforced molded body 11 and the alloy 12, first, as shown in FIG. Next, the light alloy 12 to be used as the base material is made into a molten state and poured into the mold 13, and then pressurized by the pressure punch 15 to impregnate the internal voids of the fiber-reinforced molded body 11 with the alloy 12 and solidify it.

This solidified piston 10 is taken out from the mold 13 and heat treated to form a final product.

However, 1. The piston 10 manufactured by such a method requires the manufacturing process of the fiber-reinforced molded body 11 and the alloy 12,
In particular, when heat-treating, the fiber-reinforced molded body 11 and the alloy 12
Because each composite member undergoes different thermal deformation due to the difference in coefficient of thermal expansion of the composite member, the fiber-reinforced molded body 1
Cracks may occur at the composite boundary A between Alloy 1 and Alloy 12.

In addition, in this manufacturing method, the alloy 12 is injected into the voids of the fiber-reinforced molded product 11 and impregnated, so that the air present in the voids in the fiber-reinforced molded product 11 is transferred from the mold 13 to the outside during composite. This air may not be discharged and may remain inside the fiber-reinforced molded body 11, and this air may be dissolved in the fiber-reinforced molded body 11 during heat treatment, causing blisters to occur in the fiber-reinforced molded body 11. be.

In addition, in this manufacturing method, the fiber-reinforced molded body 11 is
The fiber-reinforced molded body 1 is preheated because it comes into direct contact with 3.
1 is cooled by the mold 13 and the temperature drops during casting, making it impossible to form a good composite at an appropriate temperature.

Furthermore, since the preheated fiber-reinforced molded product 11 etc. is directly moved in and out of the mold 13, the fiber-reinforced molded product 11 may warp in the mold part during this operation, and furthermore, the mold may become dirty during the initial pouring process. There are problems such as the possibility that the molten metal remains in the fiber-reinforced molded body 11, causing deterioration in mechanical performance and quality.

The present invention aims to provide a method for manufacturing a fiber-reinforced composite member that solves the above-mentioned problems.

[Structure of the invention]

(Means for Solving the Problems) The present invention is a product in which a fiber-reinforced molded body and a casting metal serving as a base material are composited under pressure. After preheating this fiber-reinforced molded product, the porous refractory molded product is inserted into a mold so that it is inscribed in the inner wall of the mold, and the casting metal is placed in this mold. This casting metal, the fiber-reinforced molded body, and the porous refractory molded body are integrally pressure-molded to form a composite, and then this composite is taken out and mixed with the porous refractory molded body for casting. It is designed to remove unnecessary parts of metal.

(Function) Since the porous refractory molded body is layered around the outer periphery of the fiber-reinforced molded body, when the base metal for casting is injected and pressurized, the air in the fiber-reinforced molded body is absorbed into the porous refractory molded body. The object moves into the molded body,
It does not remain in the fiber-reinforced molded product, and the initially contaminated metal does not migrate to the elongated refractory molded product, thereby causing no deterioration in the properties of the molded product. Furthermore, the portions where cracks are likely to occur during cutting of the molded product are removed, thereby improving the quality of the molded product.

(Example) An example of the manufacturing method of the present invention applied to a piston will be described below with reference to the drawings. Note that the same parts as in FIGS. 4 and 5 are designated by the same reference numerals, and detailed explanation thereof will be omitted.

The fiber-reinforced molded body 20 has a cylindrical shape made of whiskers, particles, short fibers, and long fibers of ceramics, and the fiber-reinforced molded body 20 usually includes four
There are 0-95% voids.

This fiber-reinforced molded body 20 is layered with a porous refractory molded body 22 made of alumina, mullite, aluminum borosilicate, asbestos, or the like on its side and outer surfaces.

This fiber-reinforced molded body 20 is heated to 600° C. together with a porous refractory molded body 22 by a heating device (not shown) such as an electric heater.
It is preheated to a temperature of 00°C to 800°C. This preheated fiber-reinforced molded body 20 is transferred to an external porous refractory molded body 22.
is in contact with the inner wall of the mold 13 and the porous refractory molded body 2
2 is inserted into the mold 13 with the unlayered surface facing upward. Then, a molten casting metal 12 is injected into the mold 13 into which the fiber-reinforced molded body 20 is inserted. Thereafter, this metal 12 is pressurized by a pressure bunch 15, and the metal 12 is compressed into a fiber-reinforced molded body 20 and a porous refractory molded body 2.
A composite is formed by impregnating and coagulating the inside of 2. When this metal 12 is impregnated into the voids of the fiber-reinforced molded body 20, the first dirty metal 12 is transferred to the refractory molded body 22 through the voids of the fiber-reinforced molded body 20, and the fiber-reinforced molded body 10
Only the clean metal 12 in the middle remains inside.

Therefore, the fiber-reinforced molded body 20, that is, the piston 10
No deterioration of mechanical properties and quality. Furthermore, when pressurizing the cast metal 12, the air in the fiber-reinforced molded body 20 is moved to the refractory molded body 22, so the fiber-reinforced molded body 20
No blisters are generated within 0.

The piston 10 formed in this manner is removed from the mold 13 and heat treated by a heat treatment device (not shown), and then the cast metal 12 and refractory molded body 22 that are unnecessary for the piston 10 are cut by a cutting device to form a final product. A piston 10 is obtained.

During a series of manufacturing steps of the piston 10, especially during heat treatment of the fiber-reinforced molded body 20 and the cast metal 12, the thermal expansion difference is The part where cracks are likely to occur is mainly between the refractory molded body 22 and the cast metal 12, and the cracks that occur between the refractory molded body 22 and the cast metal 12 will eventually form the piston 10. Since the piston 10 is cut by a cutting device at the time of cutting, the piston 10 can be made in good condition without leaving any cracks.

Further, the refractory molded body 22 also serves as a heat insulator when the fiber-reinforced molded body 10 and the cast metal 12 are cast and pressurized in the mold 13, so that the composite can be formed at an appropriate temperature.

〔Effect of the invention〕

A porous refractory molded body is layered on a fiber-reinforced molded body, and the fiber-reinforced molded body is preheated, placed in a mold, and cast metal is injected. After forming the composite material by pressure forming the cast metal, we heat-treated it and removed the porous refractory molded body, which has good machinability, so parts that are prone to cracking can be removed during processing into the product. It is possible to obtain a molded product without cracks between the fiber-reinforced molded product and the cast metal.

Moreover, since the refractory molded body is porous, the air in the fiber-reinforced molded body moves to the refractory molded body during casting, and this air does not cause blisters to occur in the fiber-reinforced molded body. Furthermore, since the cast metal moves into the refractory molded body, the characteristics of the molded product are not degraded by the initial dirty metal.

Furthermore, since this refractory molded product also retains the heat of the fiber-reinforced molded product, a good composite member can be obtained.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view of a fiber-reinforced molded article of the present invention, FIG. 2 is a cross-sectional view of a composite of a fiber-reinforced molded article and cast metal, and FIG. 3 is a cross-sectional view of a piston manufactured by the method of the present invention. , 4th
FIG. 5 is a schematic diagram illustrating a conventional method for manufacturing a fiber-reinforced composite molded article. 10... Piston, 11.20... Fiber reinforced molded body, 12... Cast metal, 13... Mold, 14... Electric heater, 15... Pressure punch, 21... Aperture,
22... Refractory molded body.

Claims (1)

[Claims] In a product in which a fiber-reinforced molded body and a casting metal serving as a base material are composited under pressure, a porous refractory molded body is layered on one side and an outer surface of the fiber-reinforced molded body, and this fiber-reinforced molded body is After preheating the molded body, the porous refractory molded body is inserted into a mold so that it is inscribed in the inner wall of the mold, and a light alloy for casting is injected into this mold to form the casting metal and the fiber-reinforced molded body. and a porous refractory molded body are integrally pressure-molded to form a composite, and then the composite is taken out and unnecessary parts of the porous refractory molded body and the casting metal are cut and removed. Manufacturing method for composite parts