JPH0311866B2 - - Google Patents

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention relates to a method for producing structural parts for automobiles, aerospace equipment, various industrial machines, etc., or fiber-reinforced composite members used as materials thereof. .

(Prior Art) Conventionally, as shown in FIG. 1, a method for producing this type of fiber-reinforced composite member has been to produce a cylindrical material having a long fiber bundle 1 disposed inside and a filter 2 provided at the lower end. Place the mold 3 on the suction box 4, and
A method of injecting the molten metal 5 from the upper part of the molten metal 5 and simultaneously opening the valve 6 provided in the suction box 4 to reduce the pressure in the gap portions of the long fiber bundle 1 through the filter 2 and allowing the molten metal 5 to penetrate into these gap portions. As shown in FIG. 2, a molten metal 14 is placed in a container 13 with the lower part of a cylindrical mold 12 having a long fiber bundle 11 arranged therein.
As shown in FIG. A method of infiltrating the molten metal 19 into the gaps between the long fiber bundles 16 by supplying the molten metal 19 under pressure with a plunger 18 into a mold 17 in which the long fiber bundles 16 are disposed (Japanese Patent Application Laid-Open No. 57-20021)
-31467).

However, in such a conventional manufacturing method of fiber-reinforced composite members, the long fiber bundles 1, 11, 16 are simply arranged in the molds 3, 12, 17, and the long fiber bundles 1, 11, 16 are Molten metal 5 in the gap,
14, 19 because it was a method of infiltrating
In the process of the molten metal 5, 14, 19 penetrating into the gap, part or all of the long fiber bundles 1, 11, 16 may be bent or the fibers may be biased and their distribution state may become uneven. There is a problem in that even though fibers are composited into a metal matrix, the reinforcing effect of the fibers is insufficient.

(Object of the Invention) The present invention has been made by focusing on the conventional problems as described above, and in the process of infiltrating the matrix molten metal into the gap portions of the fiber bundles when manufacturing a fiber reinforced composite member, the fiber bundles are The fibers in the matrix of the manufactured composite member are not bent and their distribution is uniform and the strength is uniform. The purpose is to provide a fiber-reinforced composite member with small variations.

(Structure of the Invention) The method for manufacturing a fiber reinforced composite member according to the present invention includes providing a movable part in a mold that is displaced by the pressure of molten metal, and coupling the ends of the fiber bundles arranged in the mold to the movable part. and the movable part is displaced by the pressure of the molten metal injected into the mold to pull the fiber bundle in its length direction, so that the molten metal permeates and solidifies between the fiber bundles. It is a feature.

The mold used in this invention has a corresponding hollow cylindrical molding space when manufacturing a fiber-reinforced composite material in the shape of a round bar, for example. When manufacturing a molding machine, one having a molding space of a shape corresponding to the molding space is used.

A movable part whose position changes depending on the pressure of the molten matrix metal supplied into the mold is provided in the mold. For example, this movable part is provided at two locations when joining both ends of the fiber bundle, but it is provided at one location when joining only one end of the fiber bundle and fixing the other end of the fiber bundle to the mold. It will be done. The position of this movable part changes when it receives pressure from the molten metal, but it can also be supported by an elastic body or the like so that it returns to its original position when the pressure from the molten metal is removed.

When a matrix molten metal is injected into the mold, the movable part is displaced by the pressure of the molten metal, and the fiber bundles connected to the movable part are pulled in the longitudinal direction, and in this state, the fiber bundles are The molten metal penetrates into the gap, cools, and solidifies, yielding a fiber-reinforced composite part or material.

Therefore, while the molten metal permeates into the gap between the fiber bundles and solidifies, the fiber bundles are in a state of tension in the length direction, which may cause the fibers in the composite member to bend. It is possible to prevent unevenness from occurring.

The reinforcing fibers used in the fiber reinforced composite member of this invention include C, B, W, Mo, SiC,
Examples include Al ₂ O ₃ and Si ₃ N ₄ , and the matrix includes Al, Mg, Cu, Fe, Zn, etc. alone or in alloys.

Further, the fiber surface may be appropriately subjected to surface treatment to improve wettability with the matrix.

(Example 1) First, as shown in FIG. 4a, alumina fiber bundles 22 having an average fiber diameter of 20 μm are placed on a flat tray 21.
are arranged in a flat state, and both ends of the fiber bundles 22 are exposed from above, and a presser plate 2 is installed.
3, on both ends of the fiber bundle 22,
Al powder was sprayed by plasma spraying using a plasma torch 24 to form sprayed end portions 25 at both ends of the fiber bundle 22 .

Next, the fiber bundle 22 after being thermally sprayed with Al is
After being removed from the tray 21 as shown in FIG. 4B, the fiber bundle 22 was wound to form a cylindrical fiber bundle 23 as shown in FIG. 4C. Next, Fig. 4 d, e
As shown in FIG. 2, after metal rings 27, 27 were placed over both ends of the cylindrical fiber bundle 23 and fixed by caulking, through holes 28, 28 were provided in the metal rings 27, 27.

FIG. 5 and FIG. 6 are diagrams showing the structure of the mold used in this example, and this mold 30 is divided into an upper mold 31 and a lower mold 32, each having its own structure. It has semi-cylindrical molding spaces 31a and 32a.

Furthermore, movable members 35, 35 are disposed at both ends of the molding space 32a of the lower mold 32 as movable parts that are displaced by the pressure of the molten metal. The movable member 35 includes an upwardly protruding portion 35a that fits into the through hole 28 formed in the cylindrical fiber bundle 23, and a spring receiving portion 35b. Equipped with a lower mold 32
It is possible to slide in the left-right direction in FIG. 5 while being fitted into the grooves 32b, 32b formed in the grooves 32b, 32b. A compression coil spring 37 is disposed between the fixed member 36 attached to the left and right ends of the lower mold 32 and the spring receiving part 35b of the movable member 35, and each movable member 35 is attached to the lower mold 32. It is always pressed against the center side. At this time, as shown in FIG. 6a, the movable member 35 stops when the lower end corner 35d hits the stepped portion 32c of the lower mold 32.

Then, the upper mold 31 and the lower mold 32
A plurality of molding spaces 31a and 32a are formed in each of the molding molds 30, so that a plurality of composite members can be manufactured at once using one molding die 30. The molding spaces 31a and 32a are communicated through a runner 41, a sleeve 42 is provided at one end of the runner 41 (lower end in FIG. 5), and a plunger 43 is disposed within the sleeve 42. 43 allows supply and pressurization of molten metal.
Furthermore, a displacement meter 45 is provided so that the displacement of each movable member 35 can be measured. moreover,
A plurality of knockout pins 46 are provided in the runner 41 so as to be able to protrude upward.

In manufacturing a composite member using such a mold 30, first, the cylindrical fiber bundle 23 manufactured by the process shown in FIG. 4 is placed in the molding space 32a of the lower mold 32, and then The through holes 28 provided at both ends of the cylindrical fiber bundle 23 are connected to each movable member 35.
It fitted with the upwardly protruding portion 35a. . In this state, the cylindrical fiber bundle 23 was slightly bent.

Next, the upper mold 31 is installed on the lower mold 32, and after the molding spaces 31a and 32a are aligned to surround the cylindrical fiber bundle 23, the molten aluminum alloy is poured from the runner 41 into the molding spaces 31a and 32a. (JIS AC4B; hot water temperature 750°C) was supplied and pressurized with a plunger 43 at a pressure of about 800 Kgf/cm ² .
At this time, it was confirmed by each displacement meter 45 that at the same time as the plunger 43 pressurized the molten metal, each movable member 35 was pushed by the molten metal and moved in the direction of compressing the compression coil spring 37. That is, as each movable member 35 moves, the cylindrical fiber bundle 23 is pulled in its length direction (axial direction),
In this state, the molten alloy was immersed in the gap between the cylindrical fiber bundles 23 and solidified after cooling, to obtain a composite member in which the molten alloy penetrated into the gap between the fiber bundles 23.

After solidification of the molten alloy, the upper mold 31 was removed, and the knockout pin 46 was projected upward to take out a composite member 50 as shown in FIG. 7 from the lower mold 32. After taking out this composite member 50, the compression coil spring 37
The repulsive force causes each movable member 35 to automatically return to its original position. Note that through holes 28 are formed at both ends of the composite member 50, and the composite member 50 is cut and removed as appropriate for use.

In this invention, the fiber volume fraction Vf (%) in the fiber-reinforced composite member 50 is determined by the number of turns of the cylindrical fiber bundle 23 shown in FIG. When the volume fraction Vf value and the pressing force of the molten metal are determined, a compression coil spring 37 having a spring constant such that the fiber bundles 22, 23 will not break during pressurization is used accordingly. In addition, when it is desired to further increase the molten metal pressure, the fiber bundle 22,
A stopper 47 (see FIG. 5) may be provided to prevent excessive compression of the compression coil spring 37 so that the compression coil spring 23 does not break.

In this way, composite members having different fiber volume fractions Vf were manufactured by the conventional method and the method of the present invention, and the tensile strengths of the resulting composite members were measured, and the results are shown in FIG. 8. As shown in Figure 8,
It is clear that the composite members obtained by the method of the present invention have significantly better tensile strength than those obtained by the conventional method.

(Example 2) In this example, the sheet-like fiber bundle 22 shown in FIG. 4b is wound around a pipe 51 with both ends closed, as shown in FIG. 9, to form a cylindrical fiber bundle 23. However, a case is shown in which rings 27 are fitted to both ends of this cylindrical fiber bundle 23, and then through holes 28 are formed.

Then, a sheet-like fiber bundle 22 is attached to this pipe 51.
The cylindrical fiber bundle 23 formed by winding is placed in the mold 30 in the same manner as in Example 1, and the runner 4
The molten alloy was supplied from 1 and pressurized by the plunger 43 to infiltrate and solidify the molten alloy in the gap between the fiber bundles 23. Next, the composite member was taken out from the mold 30 and removed by cutting both ends to obtain a hollow fiber-reinforced composite member 60 as shown in FIG. 10.

(Example 3) In this example, instead of the plasma spraying of Al powder shown in FIG.
After fitting, a through hole 28 is formed, and Example 1 is completed.
After placing it in the mold 30 in the same manner as above, it was cast.

At this time, decomposed gas was generated from the phenolic resin heated by the molten aluminum alloy, but no decomposed gas remained in the resulting composite member. This is because the decomposition gas of the phenolic resin is transferred to the upper and lower molding molds 31 and 32 and the movable member 3.
It is thought that this is because the liquid flowed out toward the compression coil spring 37 through the gap between the spring 5 and the helical spring 37.

(Effects of the Invention) As explained above, according to the method for manufacturing a fiber-reinforced composite member of the present invention, a movable part that is displaced by molten metal pressure is provided in a mold, and the movable part is disposed in the mold. The ends of the installed fiber bundles are joined together, and the movable part is displaced by the pressure of the molten metal injected into the mold to pull the fiber bundles in the length direction, so that the molten metal is applied between the fiber bundles. Since the molten metal permeates and solidifies the fibers, unlike the conventional method, when the molten metal permeates into the gaps between the fiber bundles, some or all of the fiber bundles may be bent, or the fibers may become uneven and their distribution may be affected. The condition does not become uneven, and each fiber bundle becomes straight because the fiber bundle is stretched in its length direction during the process of permeation and solidification of the molten metal between the fiber bundles. The molten metal is solidified while the process is still in progress, and a very remarkable effect can be brought about in that it is possible to obtain a composite member of excellent quality with uniform fiber distribution and extremely small variations in strength.

[Brief explanation of the drawing]

Figures 1 to 3 are explanatory longitudinal cross-sectional views showing a conventional method for manufacturing a composite member, Figures 4 a to e are explanatory views sequentially showing the steps of forming a fiber bundle into a cylindrical fiber bundle, and Figure 5. 6 is an explanatory plan view of a state in which a cylindrical fiber bundle is arranged in the lower mold of the mold used in the embodiment of this invention, and FIGS. 6 a, b, c, and d are respectively A-- A, B-B, C-C, and D-D cross-sectional views; FIG. 7 is an explanatory cross-sectional view of the composite member manufactured using the mold shown in FIG. 5; FIG. A graph showing the results of examining the tensile strength of the composite member manufactured by the above method, Fig. 9 is a cross-sectional explanatory diagram of the cylindrical fiber bundle used in Example 2 of the present invention, and Fig. 10 is a graph showing the results of examining the tensile strength of the composite member manufactured in Example 2. FIG. 22...Fiber bundle, 23...Cylindrical fiber bundle, 30
... Molding mold, 35 ... Movable member (movable part), 50,
60...Composite member.

Claims (1)

[Claims] 1. A movable part that is displaced by the pressure of the molten metal is provided in the mold, and the ends of the fiber bundles arranged in the mold are connected to the movable part, and the movable part is displaced by the pressure of the molten metal injected into the mold. A method for producing a fiber-reinforced composite member, characterized in that the molten metal is permeated and solidified between the fiber bundles by displacing the fiber bundles so that the fiber bundles are stretched in the longitudinal direction thereof.