JPS606265A - Production of composite fiber member - Google Patents

Abstract

PURPOSE:To obtain a composite member which is dense and has high strength by heating and holding a fiber molding to and at the temp. of a molten metal or above and penetrating the molten metal into the gaps among the fibers under the reduced pressure then solidifying the composite consisting of the fiber molding and the molten metal under a high pressure. CONSTITUTION:A fiber molding 12 of delta-alumina is placed in a graphite crucible 11 and is quickly heated to and held at about 650 deg.C by a high frequency heating furnace 13. A melt 18 of an Al alloy is poured into the crucible and at the same time a valve 16 is opened to evacuate the inside of an evacuated vessel 15 to about 10<-1>Torr and to evacuate the inside of the molding 12 through a filter 14, thereby penetrating the molten metal 18 into the gaps of the molding 12. The inside of the vessel 15 is then leaked and immediately the composite 20 consisting of the molding 12 and the molten metal 18 is charged into a metallic mold 21 and is solidified while the composite is kept pressed to about 1,500kg/cm<2> by a punch 22. The above-mentioned composite fiber member is combined with at least a part of the casting by a casting method. The deformation such as collapsion and bend of the fibers is obviated in the stage of high pressure casting and a uniform distribution is obtd.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a fiber composite member.

Fiber composite members are made by dispersing fibers in part or all of a matrix to improve the properties of the matrix, such as pre-mechanical properties, and because the improvement in properties can be significant, it is used in many fields. Its application has been attempted and some have been put into practical use.

Conventionally, as a method for manufacturing such a fiber composite member, there has been a method as shown in FIG. 1, for example.

That is, in FIG. 1, l is a mold, 2 is an m female molded body, 3 is a molten metal, and 4 is a punch, and after the fiber molded body 2 is placed in the mold 1, the molten metal 3 is injected. Then, the molten metal 3 is solidified while being pressurized with a punch 4 (see, for example, Japanese Patent Laid-Open No. 52-60222).

However, in such a conventional manufacturing method for fiber composite members, the molten metal 3 is forced to fill the voids of the m female molded body 2 by applying high pressure with the punch 4 and solidify. When the penetration resistance of the molten metal 3 into the fiber molded body 2 increases before or during filling, the static pressure of the metal molten metal 7g, 3 increases and this pressure exceeds the compressive strength of the fiber molded body 2. In this case, defects such as deformation or breakage occur in the fiber molded body 2, such as crushing, bending, etc., and as a result, the distribution of [1] in the composite member (7%) becomes uneven,
There is a problem in that stress concentration points occur as the fibers break, making it difficult to obtain excellent properties as a composite member.

This invention was made by focusing on such conventional problems, and when manufacturing a fiber composite member in which fiber molded bodies are composited by high-pressure casting, the fiber molded bodies may be crushed or bent during high-pressure casting. To provide a method for manufacturing a fiber composite member in which defects such as deformation or breakage do not occur, the fiber distribution state in the fiber composite member after manufacturing is uniform, and stress concentration areas are not generated. The purpose is to

The method for manufacturing a fiber composite material according to the present invention includes heating and holding the fiber molded body in a molten metal composite when manufacturing a fiber composite member in which a fiber molded body is partially or completely composited by high-pressure casting. In another invention which achieves the same object, the molten metal is infiltrated into the voids inside the fiber molded body under reduced pressure, and then the fiber molded body-metal molten composite is solidified under high pressure. When partially compositing the fibrous molded body, the fibrous molded body is heated and held at a temperature lower than the temperature of the molten metal, and the molten metal is infiltrated into the voids inside the fibrous molded body under reduced pressure. - The molten metal composite is solidified under high pressure to obtain a fiber composite member, and the fiber composite member is composited into at least a portion of the casting by an appropriate casting method such as a pressure casting method or a gravity casting method. It is said that

The fibers to which this invention is applied include non-metallic (ceramic) fibers such as carbon fiber, boron fiber, alumina fiber, silicon nitride fiber, silicon carbide fiber, zirconia fiber, glass fiber, aramid fiber, steel fiber, and voice car. , glass,
There are polymer materials, etc.) and metal fibers, and it is possible to select an appropriate one depending on the purpose of use. In order to improve the wettability between the fibers and the metal (for example, in the case of a composite of C-based fibers, Cu, and A pattern), it is also possible to perform an appropriate surface treatment on the surface of the fibers.

When molding these fibers, an appropriate method can be used, such as a method in which the fibers are collected in a slurry by suction through a filter and deposited, or a method using a press.

On the other hand, low melting point metals such as A4. Mg, Cu, and alloys thereof, as well as other metals and alloys, can be selected depending on the purpose of use.

Then, the above-described appropriately shaped fiber molded body is heated and maintained at a temperature equal to or higher than the temperature of the molten metal, and the molten metal is allowed to penetrate into the voids inside the fiber molded body under reduced pressure. Therefore, by supplying the molten metal under reduced pressure, the molten metal permeates and fills every corner inside the fiber molded body, and at this time, it is necessary to prevent the fiber molded body from being deformed such as crushing or bending. is possible. After the molten metal is infiltrated into the voids inside the fiber molded body under reduced pressure, the fiber molded body-metal composite is immediately solidified under high pressure to produce a fiber composite in which the fibers are uniformly dispersed in the metal matrix. Get the parts. At this time, as a means for solidifying the molten metal under high pressure, it is convenient to solidify by mechanical pressing, but it is also possible to employ gas pressurization or the like.

The fiber composite member obtained in this way can also be applied to a fiber composite member in which fibers are dispersed in a part of the metal matrix, and in this case, the fiber molded body-molten metal composite is heated under high pressure. After solidifying to obtain a fiber composite metal, this fiber composite metal is composited into at least a portion of the casting by an appropriate casting method such as a pressure casting method or a gravity casting method.

Embodiments of the present invention will be described below based on the drawings.

[Example 1] Fig. 2 is a schematic sectional view of the apparatus used in Example 1, and in the figure, 11 is a crucible whose horizontal cross section is circular, 12 is a cylindrical fiber molded body, and 13 is a crucible having a circular horizontal cross section. 14 is a high-frequency induction heating type heating furnace consisting of a high-frequency coil 13a and a furnace frame 13b installed to heat the crucible 11 and the fiber molded body 12; 14 is installed at the bottom of the crucible 11, and allows air to pass through but not the molten metal. A filter 15 is a vacuum chamber container that communicates with the filter 14 and the inside of the crucible 11 through a -1 partial opening 15a, and this vacuum chamber container 15 is connected to a vacuum tank (not shown) through a valve 16. .

In this example, δ alumina fibers with an average diameter of 3 pm, a length of 1 to 2 mm, and a composition of 96% AM and 03-4% 5i02 are used as fibers, and these fibers are formed into a cylindrical fiber molded body (bulk density 1 .32g/cm3, Vf: 40%
) was used. Next, this fiber molded body 12
was placed in a graphite crucible 11 and rapidly heated in a high frequency heating furnace 13. At this time, the graphite crucible 11 is heated by the high-frequency heating furnace 13 and the fiber molded body 12 is heated at the same time. During this time, the temperatures of the crucible 11 and the fiber molded body 12 are measured with a non-contact thermometer, and temperature is 6
It was maintained at a constant temperature of 50'C. Next, from the second part of the fiber molded body 12 into the crucible 11, a JIS standard AC8A aluminum alloy (molten metal temperature 650°
C) 18 was injected, and at the same time, the valve 16 was opened to reduce the pressure inside the vacuum chamber container 15 to 10 −1 torr. Here, foamed gypsum is used as the filter 14, which allows air to pass through but not the molten metal 12, so the filter 14
By reducing the pressure inside the fiber molded body 12 through the fiber molded body 12, the molten alloy metal 18 penetrated gently into the voids of the fiber molded body 12 and filled every corner thereof. Thereafter, the inside of the vacuum chamber container 15 leaks, and the fiber molded body-molten metal composite 2 is immediately filled with the molten alloy 12 as shown in FIG.
0 into the mold 21 and punched 1500 by the punch 22.
The fiber composite member 25 shown in FIG. 4 was obtained by applying pressure at a pressure of kg/cm2 and coagulating under this pressure.

In the fiber composite member 25 manufactured by the method described in ``1'', there were no defects such as deformation or breakage such as crushing and bending of the fiber molded product (■2), and the fibers were uniformly and densely dispersed. As a result, a very good fiber composite metal member could be obtained.

[Example 2] Using the same apparatus as in Example 1, fibers with an average diameter of 5p were
Using a W fiber with a length of 3 mm and placing this W fiber molded body (V f = 30%) in the crucible 11 and energizing the heating furnace 13, the crucible 11 and the fiber molded body 1 are heated.
2 was heated and maintained at 1100'O.

Next, an electrolytic copper molten metal 18 at 1100°C is supplied into the crucible 11 to infiltrate and fill the fiber molded body 12 with this molten metal 18. The resulting fiber molded body-metal molten composite is shown in FIG. The composite material 20 is placed in a mold 21 shown in the figure, and the punch 22 is lowered to apply pressure to the composite material 20 at a pressure of 1500 kg/cm2, and the composite material 20 is solidified under this pressure, thereby uniformly dispersing the fibers and forming dense fibers. A composite member 25 was obtained.

[Example 3] In Example 1, the fiber molded body 12 was molded into a shape that took into account the head part of a piston for an internal combustion engine, and the other parts were the same as in Example 1, and a combustion chamber with a shape corresponding to the head part of the piston was formed. A fiber composite member 25 having a forming space 25a was manufactured. Next, this th! t%, the composite member 25 was placed in a piston forming mold 31 for an internal combustion engine (31a is a lower mold, 31b is a "-mold, 31c is a side core) shown in FIG. 5, and JIS standard AC8A molten aluminum alloy 3
2 was supplied into the mold 31, and the fiber composite member 25 was composited onto the piston head portion.

As a result of the characteristic evaluation test of the piston obtained in this way, the thermal conductivity of the fiber composite metal part was 0.10ca.
l 1cmΦsec * 00, which is less than 1/2 that of A1 alloy, improves thermal efficiency as an internal combustion engine and improves fuel consumption.
, Co, etc. can be reduced.

[Example 4] In Example 1, the fiber molded body 12 was molded into a shape that took into account the cam part of a camshaft, which is a valve mechanism component for an internal combustion engine, and the other parts were the same as in Example 1, and the cam part of the camshaft was molded. A fiber composite member 25 having a shape corresponding to the part was manufactured. Next, this fiber composite member 25 is molded into an internal combustion engine shaft forming mold 35 (35a is a sprue, 35b is a runner) as shown in FIG.

35c is a casting space. ), JIS standard A
Supplying molten C4B aluminum alloy into a mold 35,
A cam shaft was obtained by constructing a cam portion with a fiber composite member 25.

As a result of subjecting the thus obtained camshaft to a durability test, there were no problems with the abrasion resistance9 strength of the fiber composite material that constitutes the cam part, and the camshaft was equipped with a cam part with excellent characteristics. At the same time, it was confirmed that reducing the weight of the camshaft significantly improves the power performance of the internal combustion engine.

As explained above, according to the present invention, when manufacturing a fiber composite member in which a fiber molded body is partially or completely composited by high-pressure casting, the fiber molded body is heated and held at a temperature higher than the temperature of the molten metal. That #1! After infiltrating the molten metal into the voids inside the fiber molded body under reduced pressure, the fiber molded body-molten metal composite is solidified under high pressure to obtain a fiber composite member, and the fiber molded body is partially composited. In this case, since the fiber composite member is composited into at least a part of the casting by a casting method, unlike the conventional technology, the molten metal pressure increases due to the increased resistance to penetration of the molten metal into the fiber molded body. To obtain a dense and high-strength fiber composite member by being able to eliminate defects such as crushing, bending, and breakage of a fiber a molded product, and at the same time eliminating non-uniformity of dispersion. A very good effect can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view showing an example of a conventional high-pressure solidification and casting apparatus, and FIGS. 2 and 3 are longitudinal sectional views of a molten metal filling apparatus and a longitudinal cross-section of the high-pressure solidification and filling apparatus used in an embodiment of the present invention. 4 is a perspective view of a fiber composite member obtained by the apparatus shown in FIG. 3, and FIGS. 5 and 6 show a piston mold for an internal combustion engine and a camshaft mold used in an embodiment of the present invention. 7 is a longitudinal sectional view, and FIG. 7 is a sectional view taken along the line X--X in FIG. 6. 12... Fiber molded body, 18, 23.36... Molten metal, 25... Fiber composite member. kuto n τ-de-

Claims (2)

[Claims] (1) After heating and maintaining the fiber molded body at a temperature below the temperature of the molten metal and infiltrating the molten metal into the voids inside the fiber molded body under reduced pressure, the fiber molded body-molten metal composite is heated under high pressure. A method for manufacturing a fiber composite member, characterized by solidifying it. (2) After heating and maintaining the fiber molded body above the temperature of the molten metal to infiltrate the molten metal into the voids inside the fiber molded body under reduced pressure, the fiber molded body-molten metal composite is solidified under high pressure. A method for producing a fiber composite member, comprising: obtaining a fiber composite member using a casting method, and incorporating the fiber composite member into at least a portion of a casting by a casting method.