JPS5988973A - Production of fiber molded object for producing fiber reinforced metal composite material - 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 The present invention is directed to the production of a fiber-reinforced metal composite material in which reinforcing fibers are used as a reinforcing material and metal is used as a matrix. One of the methods of forming a molded body with high density and orientation has conventionally been to use a binder such as a resin or wax.

However, binders such as resins and waxes are expensive, require heating and high pressure when forming molded objects, and need to vaporize the binder at a high temperature of 400°C or higher after molding. When the binder vaporizes, odor and smoke are generated, which may cause environmental pollution and disasters.

Furthermore, at high temperatures, for example, boron fibers, carbon fibers, glass slivers, etc. may deteriorate, and the quality of the molded product may deteriorate.

The applicant of the present application has proposed a method for solving these problems and molding a reinforcing material of a composite material having a well-defined shape and density without using a binder having various drawbacks as described above. Japanese Patent Application No. 55-65666 (Japanese Unexamined Patent Publication No. 56-16112) filed by the same applicant as
'O) is used as a binder, this substance is mixed with materials such as powder, thin wire, fibers, boards, etc. at room temperature, or impregnated into a collection of the materials, and after forming the materials into a predetermined shape. proposed a method for preforming powders, fine wires, fibers, etc., which is characterized by forming compacts by cooling and solidifying them.

According to this method of forming reinforcing fibers by freezing, reinforcing fibers can be formed at lower temperatures and pressures than conventional methods that use binders such as resins and waxes, and the binder can also be vaporized at low temperatures. Since it is possible to
It is possible to efficiently mold reinforcing fibers at low cost.

However, in the method proposed above, or when forming a fiber molded body using long fibers such as carbon fibers or alumina fibers, it is necessary to form a fiber molded body in which reinforced #J & navy blue are oriented in one direction. However, it is difficult to produce a fiber molded product in which reinforcing fibers are oriented in a complicated manner according to the product shape, etc., and it is difficult to handle the fiber molded product until it is placed in a compression mold. Furthermore, there is a problem that it is difficult to produce a fiber molded article having a low (and uniform) reinforcing fiber density.

In view of the above-mentioned disadvantages of the freezing-based molding method proposed above, the present invention utilizes the advantages of the freezing-based forming method of strong seven fibers while avoiding the above-mentioned problems. It is an object of the present invention to provide an improved method for producing a fiber molded article for producing a fiber reinforced metal composite material.

According to the present invention, such an object is to form a composite fiber body made of reinforcing fibers and auxiliary fibers that disappear by combustion, and to use the composite 111f body to produce composite fibers having a predetermined shape, a predetermined reinforcing fiber density, and orientation. Forming a preform, impregnating the composite fiber preform with a substance that is liquid at room temperature, solid at low temperature, and gas at high temperature, and solidifying the substance by cooling it. This is achieved by a method for producing a fiber molded article for producing a fiber-reinforced metal composite material, which is then heated to remove the substance as a liquid or gas, and to eliminate the auxiliary fibers by combustion.

According to the method for manufacturing a fiber molded article for producing fiber-reinforced metal composite materials according to the present invention, a composite fiber body consisting of the reinforcement 134 and auxiliary fibers that disappear by combustion is formed, and the composite fiber body is used to form a predetermined shape and shape. A composite fiber preform with specified reinforcement, fiber density, and orientation is formed, and the composite fiber preform is shaped by freezing. After that, the auxiliary machine cloth is removed by combustion, so that the reinforcing fibers are auxiliary. Since the predetermined reinforcing fiber density and orientation state ensured by the fibers are maintained as they are even after the removal of the substance, a fiber molded article in which the reinforcing fibers are formed in a predetermined shape with a predetermined density and orientation state can be efficiently manufactured. be able to. In particular, according to the method of the present invention, it is possible to easily produce a fiber molded article in which the reinforcing fibers have a small and uniform density.

As one method for manufacturing a composite material, a reinforcing material is filled in a mold, and a molten metal of 71 to 60% is introduced into the mold,
A pressure casting method is known in which the molten matrix metal is solidified while being pressurized in a mold, and this pressure casting method is disclosed in an application filed by the same applicant as the present applicant. As proposed in Japanese Patent Application No. 55-1 '07 '040, in order to ensure that the molten metal of the matrix metal enters between each fiber of the reinforcing material, it is necessary to insert the reinforcing material into the matrix metal. It has been found that it is desirable to preheat the melting point of the matrix metal to a temperature higher than the melting point of the matrix metal, and maintain it at that temperature even when the matrix metal slag is introduced.

According to the method of the present invention, the fiber compact is heated in the step of burning out the auxiliary fibers from the formed fiber compact. When manufacturing a composite material using a pressure casting method, the step of preheating the fiber molded body can be omitted.

The binder used in the method of the present invention is a substance that is liquid at normal temperature, solid at low temperature, e.g. -50°C to 20°C, and gaseous at high temperature, e.g. 30°C to 300°C, such as water. The main ingredient may be other surfactants, viscosity modifiers, etc., as needed. In particular, water or water-based materials, such as mixtures of water and alcohol, are preferred because they are inexpensive and easy to handle.
In addition, benzene, formic acid, acetic acid, xylene, hydrogen peroxide, and mixtures thereof may be used.

Further, the auxiliary fibers that disappear by combustion may be organic fibers such as acrylic fibers and rayon fibers.

Furthermore, the composite fiber body in the method of the present invention is a knitted fabric, a woven fabric, a mat, a nonwoven fabric made of reinforcing fibers and auxiliary fibers, a strand made of reinforcing fibers and auxiliary fibers twisted together, etc. good.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The invention will be explained in detail below by way of example embodiments with reference to the accompanying figures.

Example 1 Carbon fiber' (Torayka (registered trademark) manufactured by Toshi Co., Ltd.) M4
'O1 fiber diameter 7μ) yarn (number of fibers 6 'O'O'
0 fibers) are stacked perpendicularly to each other, and acrylic fibers 2
By weaving (fiber diameter 15μ) as yarn,
As shown in FIG. 1, a non-crimp cloth 3 was formed using the composite fiber body.

Next, the thus formed non-crimp cloth 3 was cut into the shape of a connecting rod. In this case, the carbon fibers are 0°/9 with respect to the longitudinal axis of the connecting rod.
One 4a extends at an angle of 0' and the other 4b extends at an angle of ±45° with respect to the longitudinal axis of the connecting rod. Next, the non-crimp cloths 4a and 41 are separated and cut as shown in FIG.
) were alternately laminated to form a composite m-paper molded body 5 as shown in FIG. 3. Next, this composite fiber preform 5 was placed in a compression mold (not shown in the figure), and after filling the compression mold with water, it was compressed so that the volume ratio of the non-crimp cloth became 65%, and in that state. The water was solidified at a temperature of -40°C.

Further, the composite fiber preform 5 in which water has been coagulated in this manner
Stainless steel (JIs standard S) not shown in the diagram
Placed in a case made of US 31 'OS) and heated the whole case to a temperature of 6'O'O℃ for 10 minutes in a heating furnace.
By heating and holding for a minute, the acrylic fibers 12 as auxiliary fibers are burned and removed, and as shown in FIG.
Carbon fibers 1 oriented in a laminated manner at 90° and ±45°
A fiber molded body 6 was obtained for manufacturing a connecting rod of an IJli cloth-reinforced metal composite material sheath using the reinforcing fibers. The volume fraction of carbon fibers in the fiber molded article 6 thus produced was 50%, and almost no deterioration of the carbon fibers was observed.

Fire lid 1” - Alumina fiber 7 (FP fiber manufactured by DuPont, fiber diameter 2
By twisting the acrylic fibers 8 (fiber diameter: 15 .mu.m) and the acrylic fibers 8 (fiber diameter: 15 .mu.m), a strand 9 was formed as a 1:1 composite fiber of alumina fiber and acrylic fiber, as shown in FIG. This strand 9 is then cut to a length of 1'Qcm and stacked in one direction, resulting in a length of 1'Qcm as shown in FIG.
A composite fiber preform 10 having a width of 4 am, a thickness of i, and a thickness of 5 cm was formed. The composite fiber preform 10 thus formed is placed in a compression mold (not shown), a mixture of water and colloidal silica is introduced into the compression mold, and
After impregnating the composite fiber preform 1o with the mixture,
The mixture was lightly compressed so that the volume fraction of the strand 9 was approximately 40%, and the mixture was solidified in that state at a temperature of -40°C.

The composite III preform 10 in which the mixture has been solidified is placed in a case made of stainless steel (JIS standard S'J S 31' OS), which is not shown in the figure.
By heating and holding the case at 6'O'0°C for 10 minutes, the acrylic fibers 8 are destroyed by combustion,
As a result, as shown in FIG. 7, a fiber molded body 11 for producing a fiber-reinforced metal composite material using unidirectionally oriented alumina fibers 7 as reinforcing fibers was obtained. The volume fraction of the alumina fibers 7 in this fiber molded body 11 was very small, about 20%, and the alumina fibers 7 remained uniformly oriented along the longitudinal direction of the fiber molded body 11.

Although the present invention has been described in detail with reference to two embodiments above, the present invention is not limited to these embodiments, and various embodiments are possible within the scope of the present invention. would be obvious for ordinary wages.

[Brief explanation of drawings]

Figures 1 to 4 show the manufacturing process of one embodiment of the method for manufacturing a fiber molded article for manufacturing fiber reinforced metal composite materials according to the present invention, and Figures 5 to 7 show the manufacturing process of a fiber reinforced metal composite material according to the present invention. This is the previous article showing the manufacturing process of another example of the method for manufacturing a fiber molded article for manufacturing a composite material. DESCRIPTION OF SYMBOLS 1... Carbon fiber, 2... Acrylic fiber, 3... Non-crimp cloth, 4a, 4b... Cut non-crimp cloth, 5... Composite fiber preform, 6...
Fiber molded product, 7... Alumina fiber, 8... Acrylic fiber, 9... Strand, 10... Composite fiber preform, 11... Fiber molded product patent applicant Toyota Motor Corporation teenager
Patent Attorney Masaki Akashi No. 1 Figure 2 Figure 3 Figure 4

Claims (1)

[Claims] forming a composite fiber body consisting of reinforcing fibers and auxiliary fibers that disappear by combustion; using the composite fiber body to form a composite fiber preformed body having a predetermined shape and a predetermined reinforcing fiber density and orientation; The preform is impregnated at room temperature with a substance that is liquid at room temperature, solid at low temperature, and gaseous at high temperature, cooled to solidify the substance, and then heated to turn the substance into liquid. Alternatively, a method for producing a fiber molded article for producing a fiber-reinforced metal composite material, characterized in that the auxiliary fibers are removed as a gas and the auxiliary m-fibers are eliminated by combustion.