JPH05212531A - Forming method of metallic base composite material - Google Patents

Abstract

PURPOSE:To form a molded product having a complicated shape at a low working cost by induction-heating the top of self-consuming plunger at the neighborhood of the nozzle formed at the top of cylinder. CONSTITUTION:A self-consuming plunger 12 of column like formed of the metallic composite material is supplied inside a plunger room 14 formed in a cylinder 13, and the top of self-consuming plunger 12 is molten with the induction heating only at the neighborhood of a nozzle 20 of the cylinder 13. Therefore, the metallic base composite material is rapidly melted, pressurized with the self-consuming plunger 12 itself, ejected from a nozzle 20, and filled inside a cavity 28 of a forming die 22. Because the time until being filled is become short, and the molten state is not continued in the long time, so the metallic matrix and the adding material are not separated due to the difference of specific gravity.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for molding a metal matrix composite material.

[0002]

2. Description of the Related Art Conventionally, when molding a molded product in which short fibers, whiskers, particles and the like are dispersed in a metal matrix, molding methods such as a high pressure impregnation casting method, a casting method and a powder method have been used. In the high-pressure impregnation casting method, a preform (preform) is manufactured in advance from short fibers, particles and the like, and the molten metal matrix is impregnated into the preform at high pressure.

Further, in the casting method, additives such as short fibers, whiskers and particles are mixed in a molten metal matrix and stirred, and the molten metal is poured into a molding die for casting. Then, in the powder method, additives such as short fibers, whiskers, and particles are mixed with the powder of the metal matrix, and the powder is supplied into the cavity of the mold and pressurized, or injected into the mold. Molded by and then
I try to sinter.

[0004]

However, in the above-mentioned conventional method for forming a metal-based composite material, in the case of the high-pressure impregnation casting method, the molten metal is impregnated into the preformed body at a high pressure, so that it is sufficient. Since it is difficult to perform various impregnations, not only a molded product having a complicated shape cannot be molded, but also internal defects are likely to occur. In addition, it is necessary to manufacture a preform for molding, which complicates the manufacturing process and increases the working cost.

Further, in the case of the casting method, the additives cannot be uniformly mixed in the molten metal and the reaction between the metal matrix and the additives is likely to occur, which deteriorates the quality of the molded product. I will end up. In the case of the powder method, not only the molding process becomes complicated and the working cost becomes high, but also internal defects are apt to occur and the quality of the molded product deteriorates. In addition, the dimensional accuracy is poor and it is difficult to form a complicated shape.

The present invention solves the problems of the conventional method for molding a metal-based composite material, has a low working cost, can mold a molded product having a complicated shape, and has high dimensional accuracy.
Moreover, it is an object of the present invention to provide a method for molding a metal matrix composite material which can improve the quality of a molded product.

[0007]

Therefore, in the method for forming a metal matrix composite material of the present invention, a columnar cylinder formed of a metal matrix composite material comprising a metal matrix and an additive is provided in a plunger chamber formed in a cylinder. Of the self-consumable plunger, and the tip of the self-consumable plunger is melted by induction heating only in the vicinity of the nozzle formed at the tip of the cylinder.

The molten metal matrix composite material is pressurized by the self-consuming plunger itself and is ejected from the nozzle.
Then, the injected metal matrix composite material is filled in the cavity of the molding die that is arranged so as to face the nozzle.

[0009]

According to the present invention, a self-consuming plunger formed of a metal matrix composite material comprising a metal matrix and an additive is supplied into the plunger chamber formed in the cylinder as described above, and is formed at the tip of the cylinder. The tip of the self-consuming plunger is melted by induction heating only in the vicinity of the nozzle. Therefore, the metal matrix composite melts rapidly.

The molten metal matrix composite material is pressurized by the self-consuming plunger itself and injected from the nozzle. Then, the injected metal matrix composite material is filled in the cavity of the molding die that is arranged so as to face the nozzle. Therefore, the time until filling is shortened.

[0011]

Embodiments of the present invention will now be described in detail with reference to the drawings. FIG. 1 is a sectional view of an essential part of a molding apparatus to which the molding method for a metal-based composite material of the present invention is applied.
In the figure, 12 is a self-consuming plunger formed in a columnar shape by a metal matrix composite material, 13 is a cylinder that accommodates the self-consuming plunger 12, and the self-consuming plunger 12 is driven by a plunger driving device (not shown). It is driven and slides downward in the plunger chamber 14 formed by the cylinder 13. The plunger driving device is controlled by a control device (not shown), and the descending speed of the self-consuming plunger 12 can be set to an arbitrary value.

The cylinder 13 includes a low temperature side cylinder part 15 made of steel, a heat insulating cylinder part 16 made of a material having a high heat insulating property such as ceramics, and a high temperature side cylinder part 18 made of heat resistant metal or conductive ceramics. And they are continuously formed from the upper side to the lower side. Two
Reference numeral 0 denotes a nozzle made of heat-resistant metal or conductive ceramics formed at the tip of the high temperature side cylinder portion 18.

Reference numeral 31 is a coil for high frequency induction heating, which is arranged close to the periphery of the high temperature side cylinder portion 18. The high-frequency induction heating coil 31 receives a drive current from a high-frequency power supply device (not shown), generates a high-frequency induction current in the high temperature side cylinder portion 18, and heats the high temperature side cylinder portion 18 by high frequency induction heating. in this case,
The high frequency power supply device receives a signal from the control device and supplies a set drive current to the high frequency induction heating coil 31. Since the high-frequency induction heating coil 31 heats only the vicinity of the nozzle 20, the tip of the self-consumption type plunger 12 is rapidly melted.

The self-consumable plunger 12 is composed of a metal matrix composite material in which a powdery metal matrix and additives such as short fibers, whiskers and particles are compounded, and the metal matrix composite material is formed into a cylindrical shape. Is used. Therefore, when the tip of the self-consumable plunger 12 is heated and melted by the high-frequency induction heating coil 31, the molten metal-based composite material is accumulated in the portion surrounded by the high temperature side cylinder portion 18 in the plunger chamber 14. Be done. Then, when the plunger driving device lowers the self-consumable plunger 12, the molten metal matrix composite material is injected through the nozzle 20. As described above, the self-consumable plunger 12 is a raw material and at the same time has a function of a plunger for pressurizing the molten metal matrix composite material.

Reference numeral 22 is a mold made of heat-resistant metal or ceramics, and the fixed side and the movable side of the parting line are brought into contact with and separated from each other by a mold opening / closing device (not shown). The mold 22 includes a sprue 24 that opens at a position corresponding to the nozzle 20 and a cavity 2 that communicates with the sprue 24.
Have eight. At an appropriate position on the upper end of the cavity 28,
A vent (not shown) is formed so as to communicate with the outside of the molding die 22, and the air in the cavity 28 when the molten metal matrix composite material is filled is discharged through the vent.

Next, the operation of the molding apparatus having the above construction will be described. When the self-consuming plunger 12 is lowered in the plunger chamber 14 by a plunger driving device (not shown), the control device supplies a driving current set to the high frequency induction heating coil 31 via a high frequency power supply device, The high temperature side cylinder portion 18 is heated. The tip of the self-consuming plunger 12 is heated and the nozzle 20
Melts near.

As described above, since the self-consuming type plunger 12 is lowered in the plunger chamber 14 and only the vicinity of the nozzle 20 is rapidly heated so that the tip of the self-consuming type plunger 12 is melted, it is melted. The time from molding to molding is shortened, the metal matrix and the additive are not separated due to the difference in specific gravity, the metal matrix composite can be maintained in a uniform mixed state, and the stirring work is unnecessary. ..

Further, the reaction between the metal matrix and the additive can be suppressed as much as possible. Subsequently, the plunger driving device further lowers the self-consumable plunger 12, presses the molten metal-based composite material at the tip of the self-consumable plunger 12, and the pressed metal-based composite material is ejected from the nozzle 20. Is ejected. The injected metal matrix composite material is sent to the sprue 24 of the molding die 22, and the cavity 28
Filled inside. At this time, the air existing in the cavity 28 is discharged to the outside through the vent.

The molten metal matrix composite material has a cavity 28.
After filling the inside, the plunger driving device is controlled to hold the pressure for a while. Then, the molding die 22 is depressurized to move and separate, and the molded product is taken out from the cavity 28. In this case, the vicinity of the nozzle 20 can be cooled. Since the molded product is molded by the die casting method,
It becomes possible to cool rapidly and a fine structure can be formed inside the molded product. Therefore, the quality of the molded product is improved, a molded product having a complicated shape can be molded, and the dimensional accuracy can be improved.

The above-mentioned steps are usually carried out under vacuum and in the presence of an inert gas, although it depends on the composition of the metal matrix. In addition, if necessary, the nozzle 20 is heated,
It is possible to cool the mold 22
It is advisable to be able to preheat or cool such items.

In the drawing, the nozzle 20 is arranged so as to open downward, and the nozzle is ejected downward. However, the nozzle 20 can be ejected in either the upward direction or the lateral direction as required. It should be noted that the present invention is not limited to the above-described embodiments, and various modifications can be made based on the spirit of the present invention, and these are not excluded from the scope of the present invention.

[0022]

As described above in detail, according to the present invention, a cylindrical self-consumable plunger molded of a metal matrix composite material including a metal matrix and an additive is provided in a plunger chamber formed in a cylinder. It is supplied and the tip of the self-consuming plunger is melted by induction heating only in the vicinity of the nozzle formed at the tip of the cylinder. Therefore, the metal matrix composite melts rapidly.

The molten metal matrix composite material is pressurized by the self-consuming plunger itself and injected from the nozzle.
Then, the injected metal matrix composite material is filled in the cavity of the molding die that is arranged so as to face the nozzle.
Therefore, the time until filling is shortened and the molten state does not last for a long time, so that the metal matrix and the additive are not separated due to the difference in specific gravity.
Further, the additive can be uniformly dispersed in the metal matrix without performing a stirring operation. Further, the reaction between the metal matrix and the additive can be suppressed as much as possible.

Since the preform is unnecessary, the work can be simplified and the work cost can be reduced.
Furthermore, since the molded product is molded by the die casting method,
It becomes possible to cool rapidly and a fine structure can be formed inside the molded product. Therefore, the quality of the molded product is improved, a molded product having a complicated shape can be molded, and the dimensional accuracy can be improved.

[Brief description of drawings]

FIG. 1 is a sectional view of an essential part of a molding apparatus to which a molding method for a metal-based composite material of the present invention is applied.

[Explanation of symbols]

 12 Self-consumable Plunger 13 Cylinder 14 Plunger Chamber 20 Nozzle 22 Mold 28 Cavity 31 High Frequency Induction Heating Coil

Claims (1)

[Claims] 1. A cylindrical self-consuming plunger formed of a metal matrix composite material comprising a metal matrix and an additive is supplied into a plunger chamber formed in the cylinder, and (b) the tip of the cylinder. Only in the vicinity of the nozzle formed in, the tip of the self-consuming plunger is melted by induction heating, and (c) the molten metal matrix composite material is pressurized by the self-consuming plunger itself and injected from the nozzle, d) A method of molding a metal-based composite material, which comprises filling the inside of a cavity of a molding die arranged so as to face the nozzle.