JPH0448544B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a composite material comprising a reinforcing material such as fiber, thin wire material, powder material, whisker, etc., and a matrix metal.

As a type of composite material, fiber-reinforced metal materials are reinforced with high-strength, high-elasticity fibers made of boron, carbon, alumina, silica, and silicon carbide, and the matrix is metals such as aluminum and magnesium or their alloys. (FRM) is known, and various methods for manufacturing such fiber-reinforced metal materials have been proposed.

One of the conventional methods for manufacturing these fiber-reinforced metal materials is to fill a mold with fiber reinforcement, then introduce molten matrix metal into the mold, and then use a plunger that engages with the mold to remove the molten matrix metal. A so-called high-pressure casting method is known in which metal is solidified while being pressurized in a mold.

In this high-pressure casting method, the molten matrix metal is pressurized by a plunger, and the pressurized molten matrix metal removes the air that existed between each fiber of the reinforcing material before casting. Penetrate. Therefore, not all the air that existed between each fiber of the reinforcing material before casting is removed from between each fiber during casting, and some air remains between each fiber after casting, resulting in Cavities may form within the composite material and the bond between the reinforcement and the matrix metal may be insufficient.

Furthermore, as described in, for example, Japanese Unexamined Patent Publication No. 50-144629, a method is already known in which high-pressure casting is performed after reducing the pressure in the mold. According to this method,
A high-performance composite material can be produced compared to a simple high-pressure casting method in which the pressure inside the mold is not reduced.

However, in this method, the pressure inside the mold is first reduced, and then the molten matrix metal is poured into the mold. A conduit that connects the mold and melting furnace, and an on-off valve that controls communication between the conduit are essential, and the mold, conduit, and their connections must be highly airtight, so the equipment is complicated. The problem is that it has to be expensive.

Furthermore, in the method described in the above publication, not only the inside of the mold but also the inside of the conduit connecting the mold and the melting furnace must be depressurized, so the depressurization process takes a relatively long time, and one Each time the production of composite material is completed, the matrix metal solidifies in the conduit and on-off valve, so when producing the next composite material, it is necessary to reduce the pressure inside the mold and then pour the molten matrix metal. In this case, it is necessary to replace the conduit with a new conduit including the on-off valve, or to melt the matrix metal in the conduit using a heater etc. after reducing the pressure in the mold, which makes it difficult to manufacture composite materials efficiently and at low cost. The problem is that it can't be done.

Furthermore, in order to ensure that the molten metal of the molten matrix metal penetrates between the fibers of the reinforcing material, etc., Japanese Patent Application No. 55-107040 (Unexamined Patent Publication No. It is preferable to preheat the reinforcing material to a temperature higher than the melting point of the matrix metal prior to casting, as proposed in No. 57-31467), but as mentioned above, the depressurization process requires a relatively long time. However, there is a problem in that the reinforcing material that has been preheated is cooled down by heat absorption by the mold, and therefore the desired effect of preheating the reinforcing material cannot be fully achieved.

In view of the above-mentioned problems in the conventional high-pressure casting method, the present invention reliably eliminates the air existing between each fiber of the reinforcing material and reliably infiltrates the molten matrix metal between each fiber. The purpose of the present invention is to provide a method that can efficiently and inexpensively produce a high-quality composite material with excellent adhesion between the reinforcing material and the matrix metal.

According to the present invention, the present invention provides a molding chamber for casting a composite material consisting of a matrix metal and a reinforcing material, a pressurizing chamber that communicates directly with the molding chamber, and a molten metal introduced into the pressurizing chamber. Using a casting apparatus having a pressurizing means for pressurizing matrix metal, pouring molten matrix metal into the pressurizing chamber with the reinforcing material filled in the molding chamber, and forming a part communicating with the pressurizing chamber. This is achieved by a method for producing a composite material, in which the pressure inside the molding chamber is reduced from the opposite side, and then the molten matrix metal is solidified while being pressurized by the pressurizing means.

According to the method of the present invention, molten matrix metal is poured into a pressurizing chamber that directly communicates with the molding chamber, so that the molding chamber is in a state where communication with the pressurizing chamber is cut off by the molten matrix metal. The pressure is reduced and the air is efficiently and reliably removed from between each fiber of the reinforcing material filled in the molding chamber, so that no air remains between each fiber of the reinforcing material and melting is possible. The matrix metal penetrates well between each fiber of the reinforcing material, making it possible to produce a high-quality composite material with excellent adhesion between the reinforcing material and the matrix metal. Even when the pressure is high, a composite material can be produced satisfactorily without setting the pressure applied to the molten matrix metal by the pressure means to be high.

Further, according to the method of the present invention, the pressurizing chamber and the molding chamber of the casting apparatus used are in direct communication with each other, and after the molten matrix metal is poured into the pressurizing chamber, the pressure inside the molding chamber is reduced. The only space that needs to be depressurized and air removed is the relatively narrow molding chamber filled with reinforcing material, and the matrix metal solidifies only in the pressurizing chamber and molding chamber of the casting equipment, and the solidified material is not cast after casting. It can be easily removed from the equipment, and the same casting equipment can be reused many times. Therefore, compared to the method described in JP-A-50-144629, the time required to reduce the pressure inside the molding chamber is shorter, less energy is required, and no conduits or on-off valves are required. Therefore, there is no need to replace the conduit or remelt the matrix metal within the conduit, so that the above-mentioned high quality composite material can be produced efficiently and at low cost.

Also in the method of the present invention, it is preferable to preheat the reinforcing material to a temperature higher than the melting point of the matrix metal prior to casting. After the molten matrix metal is poured, the pressure within the molding chamber is reduced so that at least a portion of the reinforcement remains in contact with the hot molten matrix metal during the depressurization process, and the time required for the depressurization is short. Therefore, compared to the method described in JP-A-50-144629 mentioned above, the temperature drop in the reinforcing material is smaller, which improves the permeability of the matrix metal between the individual reinforcing materials and the reinforcing material. It is possible to produce a composite material with even better adhesion between the metal and the matrix metal.

Further, in order to easily fill the reinforcing material into the molding chamber and to take out the solidified material formed in the pressurizing chamber and the molding chamber from the casting device, the casting device generally has a plurality of pieces that abut each other at the parting surface. It is composed of the following types. According to the method of the present invention, since molten matrix metal is poured into the pressurizing chamber before the pressure inside the molding chamber is reduced, air from outside the molding apparatus flows into the pressurizing chamber through the space between the parting surfaces. This prevents the molding chamber from being depressurized to a sufficiently low pressure, and also prevents some of the molten matrix metal poured into the pressurizing chamber from entering the space between the parting surfaces. Therefore, a means for sealing between these parting surfaces may be unnecessary or simple. Therefore, the casting apparatus for carrying out the method of the present invention is suitable for carrying out the method described in the above-mentioned publication. It may be simpler than a casting device for casting.

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

FIGS. 1 and 2 are schematic longitudinal sections showing a first embodiment of a manufacturing apparatus that may be used to carry out the method for manufacturing a composite material according to the present invention, in a depressurization process in a molding chamber and a composite material casting process, respectively. It is a front view. In these figures, 1 indicates a composite material manufacturing device, and this composite material manufacturing device 1 has a molding chamber 3 for casting a composite material made of matrix metal and reinforcing material 2; A mold 5 having a pressurizing chamber 4 in communication with it, a plunger 7 that fluid-tightly fits into the pressurizing chamber 4 and pressurizes the molten matrix metal 6 introduced into the molding chamber 3 and the pressurizing chamber 4, and the mold. The molding chamber 3 is reciprocatably received in a bore 8 formed in the molding chamber 3.
It also includes a knockout pin 9 for taking out the solidified material solidified in the pressurizing chamber 4 from the mold 5, and a pressure reducing device 10 for reducing the pressure inside the molding chamber 3. The pressure reducing device 10 is provided along the longitudinal direction of the bore 8 so as to be spaced apart from each other.
The end opposite to the side that communicates with (lower end in the figure)
A plurality of passages 11 that communicate with the outside of the mold 5
and mold 5 and knockout pin 9 provided around the opening of bore 8 and seals 12 and 1, respectively.
A vacuum pump 16 is connected to the plenum 14 in a gas-tight manner via a conduit 15. The upper end 17 of the knockout pin 9 is formed in the shape of an inverted cone and is received in the conical inner circumferential surface 18 of the bore 8, and the upper end 17 of the plunger 9 allows the passage 11 to connect the molding chamber 3 and the plenum 14. The opening and closing of communication with the building is now controlled.

The method for manufacturing a composite material according to the present invention, which is carried out using the composite material manufacturing apparatus configured as described above, is carried out as follows. First, as shown in FIG. 1, the knockout pin 9 is slightly lifted to create a slight gap between its upper end 17 and the conical inner circumferential surface 18 of the bore 8, and the molding chamber 3 is reinforced. The material 2 is filled, and in this state, molten matrix metal is poured into the pressurizing chamber 4. Next, the vacuum pump 16 is operated to reduce the pressure inside the plenum 14 and the molding chamber 3 to a predetermined pressure. After several seconds have passed in this state, the plunger 7 is fitted into the pressurizing chamber 4 and slowly lowered, and the knockout pin 9 is lowered just before the lower end of the plunger 7 contacts the molten matrix metal 6. The communication of the passage 11 is cut off, and at the same time, the operation of the vacuum pump 16 is stopped. Next, the plunger 7 pressurizes the molten matrix metal 6 in the pressurizing chamber 4 to a predetermined pressure, and the pressurizing chamber 4
The pressurized state is maintained until the molten matrix metal in the molding chamber 3 is completely solidified, and after the molten matrix metal 6 in the mold 5 is completely solidified, the solidified body is removed from the mold by the knockout pin 9. 5, and the composite material formed in the molding chamber 3 is obtained by removing the solidified body consisting only of the matrix metal solidified in the pressurizing chamber 4 from the solidified body by cutting or the like.

Using the composite material manufacturing apparatus configured as described above, a composite material consisting of aluminum fibers as a reinforcing material and molten aluminum alloy as a matrix metal was manufactured as follows. First, the length is 80mm
Alumina fibers (fiber diameter 20μ, Dupont FP fibers) are oriented in one direction and bundled so that the volume ratio is 55%, and this is fixed with an inorganic binder to form the reinforcing material molded body 2. Formed. Next, this reinforcing material molded body 2 was heated to 800° C. in air.

Next, as shown in FIG.
With a gap of approximately 0.5 mm provided between the upper end 17 and the conical inner circumferential surface 18 of the bore 8, the mold 5 is
The molding chamber 3 was filled with the reinforcing material molded body 2. Next, an aluminum alloy (JIS
By pouring molten metal of standard AC4C) and operating the vacuum pump 16 at the same time, the plenum 1 is
4 and the inside of the molding chamber 3 was reduced to about 0.01 Kg/cm ² .
Next, the plunger 7 is fitted into the pressurizing chamber 4 and slowly lowered, and just before the lower end of the plunger comes into contact with the molten aluminum alloy 6, the knockout pin 9 is lowered to cut off communication with the passage 11. At the same time, the operation of the vacuum pump 16 was stopped. Next, the molten aluminum alloy 6 in the pressurizing chamber 4 is pressurized to a pressure of 1300 Kg/cm ² by the plunger 7, and the molten aluminum alloy 6 in the pressurizing chamber 4 and the forming chamber 3 is
After the molten aluminum alloy 6 in the mold 5 has completely solidified, the solidified body is taken out from the mold 5 by the knockout pin 9 and the solidified body is heated. A composite material formed in the molding chamber 3 was obtained by removing the solidified body consisting only of the aluminum alloy solidified in the pressure chamber 4 by cutting.

When longitudinal and cross sections of the composite material thus produced were observed using an electron microscope, it was found that there was almost no air trapped between the FP fibers.
It was observed that the aluminum alloy penetrated well between the FP fibers throughout the composite material. In addition, a tensile test piece was prepared from this composite material and the tensile strength was measured, and this composite material showed a high tensile strength of 65 kg/mm ² .

FIGS. 3 and 4 are schematic longitudinal sections showing a second embodiment of the manufacturing apparatus that may be used to carry out the method for manufacturing a composite material according to the present invention, respectively, during a depressurization process in a molding chamber and a composite material casting process. It is a front view. In these figures, members that are substantially the same as those shown in FIGS. 1 and 2 are designated by the same reference numerals.

In the composite material manufacturing apparatus of this embodiment, the mold 5 is provided with a wedge-shaped passage 18 that communicates and connects the lower part of the molding chamber 3 with the outside of the mold 5.
A wedge-shaped valve element 19 is inserted into the wedge-shaped passage 18 to control opening and closing of communication between the molding chamber 3 and the plenum 14 through the passage 18 . This valve element 19 is held in the closed position as shown in FIG. As shown in FIG. 3, the pin 22 is removed from the grooves 20 and 21 and moved to the left in the figure, thereby separating the inside of the molding chamber 3 and the plenum 14. We are beginning to achieve communication between the two countries. Further, a sealing device 23 is provided between the mold 5 and the knockout pin 9, and this sealing device 23 seals the knockout pin 9 and the bore when the pressure inside the molding chamber 3 is reduced by the vacuum pump 16. Air is prevented from flowing into the molding chamber 3 from outside the mold 5 through the space between the mold 5 and the mold 5.

The method for manufacturing a composite material according to the present invention, which is carried out using the composite material manufacturing apparatus configured as described above, is carried out as follows. First, the reinforcing material 2 is filled into the molding chamber 3 of the mold 5, and in this state, molten matrix metal is poured into the pressurizing chamber 4. Next, as shown in FIG. 3, the pin 22 is removed to establish communication between the molding chamber 3 and the plenum 14, and at the same time, the vacuum pump 16 is activated to bring the inside of the plenum 14 and the molding chamber 3 to a predetermined pressure. Reduce the pressure to After several seconds have passed in this state, the plunger 7 is inserted into the pressurizing chamber 4.
The pins 22 are inserted into the grooves 20 and 21 just before the lower end of the plunger 7 comes into contact with the molten matrix metal 6, thereby establishing communication between the molding chamber 3 and the plenum 14. is shut off, and at the same time, the operation of the vacuum pump 16 is stopped. Next, the molten matrix metal 6 in the pressurizing chamber 4 is pressurized to a predetermined pressure by the plunger 7,
The pressurized state is maintained until the molten matrix metal in the pressurizing chamber 4 and the molding chamber 3 is completely solidified, and after the molten matrix metal 6 in the mold 5 is completely solidified, the solidified body is removed from the knockout pin 9. The composite material formed in the molding chamber 3 is removed from the mold 5 by cutting, and the solidified body consisting only of the matrix metal solidified in the pressurizing chamber 4 is removed from the solidified body by cutting or the like. get.

FIG. 5 is a diagrammatic longitudinal section similar to FIGS. 1 and 3 showing a third embodiment of a manufacturing apparatus that may be used to carry out the method for manufacturing a composite material according to the present invention during a depressurization process in the molding chamber. Top view, Figure 6 is the line of Figure 5 -
FIG. In these figures, members that are substantially the same as those shown in FIGS. 1 to 4 are designated by the same reference numerals.

In the composite material manufacturing apparatus of this embodiment, the mold 5 includes a lower mold member 24 and an upper mold member that cooperates with the plunger 7 and the knockout pin 9 to define the pressurizing chamber 4 and the molding chamber 3, respectively. 25, and are held in contact with each other as shown in FIG. 5 by pressure holding means such as a ram device (not shown). The upper surface 26 of the lower mold member 24 is provided with a wheel-shaped groove 27 around the bore 8;
is communicated by a groove 28 to the outer peripheral surface of the lower mold member 24 to which the plenum 14 is attached. These grooves 27 and 28 are formed on the lower mold member 24 so that the upper mold member 25 has its lower surface 29 and the lower mold member 2.
When the upper surface 26 of 4 is placed in contact with the lower surface 29, the molding chamber 3 is moved into the plenum 14.
It is designed to define a passageway that communicates with and connects with.

The method for manufacturing a composite material according to the present invention, which is carried out using the composite material manufacturing apparatus configured as described above, is carried out as follows. First, the upper mold member 25 and the lower mold member 24 of the mold 5 are held in contact with each other as shown in FIG. The molten matrix metal is poured into the pressurized chamber 4. Next, the vacuum pump 16 is operated to reduce the pressure inside the plenum 14 and the molding chamber 3 to a predetermined pressure. After several seconds have passed in this state, the plunger is inserted into the pressurizing chamber 4 and slowly lowered, causing the molten matrix metal 6 in the pressurizing chamber 4 to pass through the reinforcing material 2 and form the groove 27.
At the point when the liquid has oozed out into the liquid, the operation of the vacuum pump 16 is stopped. Next, the molten matrix metal 6 in the pressurizing chamber 4 is pressurized to a predetermined pressure by the plunger 7, and the pressurized state is maintained until the molten matrix metal in the pressurizing chamber 4 and the molding chamber 3 is completely solidified. After the molten matrix metal in the mold 5 is completely solidified, the solidified body is taken out from the mold 5 by the knockout pin 9, and the solidified body is solidified only from the solidified matrix metal in the pressurizing chamber 4. By removing the body by cutting etc.
A composite material formed in the molding chamber 3 is obtained. In this embodiment, the seal at the lower end of the molding chamber 3 is automatically sealed as the molten matrix metal 6 seeped into the groove 27 is cooled by the upper mold member 25 and the lower mold member 24 and solidified in the groove 27. is achieved.

FIG. 7 and FIG. 8 are illustrative diagrams showing a fourth embodiment of the manufacturing apparatus that may be used to carry out the method for manufacturing a composite material according to the present invention, respectively, at a step of starting depressurization in a molding chamber and a step of manufacturing a composite material. FIG.
In these figures, parts that are substantially the same as those shown in FIGS.
The same reference numerals as those in the figure are given.

In the composite material manufacturing apparatus of this embodiment, the mold consists of an upper mold 5a and a lower mold 5b, and these upper molds and lower molds are held under pressure by a ram device (not shown). By means of means, the molds are maintained in a clamped state when assembled together as shown in FIGS. 7 and 8. A runner 30 for pouring molten matrix metal 6 into the pressurizing chamber 4 is formed in the upper mold 5a. A cylinder bore 31 communicating with the pressurizing chamber 4 is formed in the lower mold 5b, and a knockout pin 32 that reciprocates along the cylinder bore is inserted through the cylinder bore. The upper end surface of the knockout pin 32 defines the bottom surface of the pressurizing chamber 4. Knockout pins 35 and 36 are inserted into bores 33 and 34 of the lower mold 5b communicating with the molding chamber 3 to take out the solidified material solidified in the molding chamber 3 from the lower mold 5b.

The method for manufacturing a composite material according to the present invention, which is carried out using the composite material manufacturing apparatus configured as described above, is carried out as follows. First, the reinforcing material 2 is filled into the molding chamber 3, and the vacuum pump 16 is operated while the communication between the molding chamber 3 and the pressurizing chamber 4 is cut off by the knock-out pin 32, as shown in FIG. Thus, molten matrix metal 6 is poured into pressurizing chamber 4 through runner 30. Next, knockout pin 3
2 and plunger 7 to introduce the molten matrix metal 6 into the molding chamber 3, the plenum 1
4 and the inside of the molding chamber 3 is reduced to a predetermined pressure. After several seconds have passed in this state, the vacuum pump 16
The molten matrix metal 6 in the pressurizing chamber 4 is pressurized to a predetermined pressure by stopping the operation of the pressurizing chamber 4 and the molten matrix metal 6 in the molding chamber 3 by slowly lowering the plunger 7. After the molten matrix metal 6 in the pressurizing chamber 4 and the molding chamber 3 has completely solidified, the upper mold 5a and the lower mold 5b are released, and the solidified material is released. It is taken out from the lower mold 35b by the knockout pins 32 and knockout pins 35 and 36, and the solidified body made only of the matrix metal solidified in the pressurizing chamber 4 is removed from the solidified body by cutting or the like, thereby forming the solidified body. A composite material formed in chamber 3 is obtained.

Although the present invention has been described above in detail with reference to several embodiments, the present invention is not limited to these embodiments, and various embodiments are possible within the scope of the present invention. This will be clear to those skilled in the art.

[Brief explanation of the drawing]

FIGS. 1 and 2 are schematic longitudinal sections showing a first embodiment of a manufacturing apparatus that may be used to carry out the method for manufacturing a composite material according to the present invention, in a depressurization process in a molding chamber and a composite material casting process, respectively. The plan view, FIG. 3, and FIG. 4 are illustrations showing a second embodiment of the manufacturing apparatus that may be used to carry out the method for manufacturing a composite material according to the present invention, respectively, in the depressurization process in the molding chamber and the composite material casting process. The diagrammatic longitudinal sectional view, FIG. 5, is similar to FIGS. 1 and 3 showing a third embodiment of the manufacturing apparatus that may be used to carry out the method for manufacturing a composite material according to the present invention, in a depressurization process in the molding chamber. Similar schematic longitudinal section, No. 6
The figure is a plan cross-sectional view taken along the line 5 in FIG. FIG. 3 is an illustrative longitudinal sectional view showing a starting process and a composite material casting process. 1... Composite material manufacturing device, 2... Reinforcement material, 3...
...Molding chamber, 4...Pressure chamber, 5...Mold, 5a...
Upper mold, 5b... lower mold, 6... molten matrix metal, 7... plunger, 8... bore, 9... knockout pin, 10... pressure reducing device, 11... passage, 12, 13... seal , 14...plenum,
15... Conduit, 16... Vacuum pump, 17... Upper end, 18... Conical inner peripheral surface, 19... Valve element, 2
0, 21...Groove, 22...Pin, 23...Seal device, 24...Lower mold member, 25...Upper mold member, 26...Top surface, 27, 28...Groove, 29...
...bottom surface, 30...runner, 31...cylinder bore,
32... Knock out pin, 33, 34... Bore, 35, 36... Knock out pin.

Claims (1)

[Claims] 1. A molding chamber for casting a composite material made of a matrix metal and a reinforcing material, a pressurizing chamber directly communicating with the molding chamber, and a pressurizing means for pressurizing the molten matrix metal introduced into the pressurizing chamber. Using a casting apparatus having a molding chamber, molten matrix metal is poured into the pressurizing chamber with the reinforcing material filled in the molding chamber, and the molten matrix metal is poured into the molding chamber from a portion on the opposite side of the portion communicating with the pressurizing chamber. A method for manufacturing a composite material, comprising: reducing the pressure of the molten matrix metal, and then solidifying the molten matrix metal while pressurizing it with the pressurizing means.