KR20040027264A - Die-casting process for rheocasting method and apparatus thereof - Google Patents

Abstract

PURPOSE: A die casting method for rheocasting and a die casting apparatus for rheocasting are provided to obtain more fine and uniformed spheroidized grains, improve energy efficiency, reduce manufacturing cost, improve mechanical properties, simplify casting process and shorten manufacturing period of time. CONSTITUTION: The die casting method for rheocasting comprises a step of forming a metal slurry by impressing electromagnetic field to a slurry manufacturing region of sleeve connected to a forming die into one end of which plunger is injected, and at the other end of which a forming cavity is formed and injecting molten metal into the slurry manufacturing region; and a step of injecting the metal slurry into the forming cavity of the forming die by pressing the plunger, wherein the sleeve is arranged with being horizontal to the ground, and the slurry manufacturing region of the sleeve is a region formed by the plunger and an open-and-shut door opened and closed with being installed in the sleeve, wherein the sleeve is arranged in such a way that the sleeve is inclined to the ground so that one end part of the sleeve into which the plunger is inserted is directed to the ground, and the slurry manufacturing region of the sleeve is a region formed with one end of the slurry manufacturing region being closed by the plunger, wherein the sleeve is installed in such a way that one end part of the sleeve into which the plunger is inserted is rotated to a certain angle for the ground, and the slurry manufacturing region of the sleeve is a region formed with one end of the slurry manufacturing region being closed by the plunger, and wherein the sleeve is arranged in such a way that the sleeve is perpendicular to the ground so that one end part of the sleeve into which the plunger is inserted is directed to the ground, and the slurry manufacturing region of the sleeve is a region formed with one end of the slurry manufacturing region being closed by the plunger.

Description

Die-casting method and apparatus for the reaction high molding

The present invention relates to a die casting method and apparatus for reactive solidification, and more particularly, to a die casting method and apparatus for reactive solidification capable of fine and uniform crystal grain structure.

Refractive solidification (rheocasting) refers to a processing method for producing a billet or a final molded product by casting or forging a solidified solid slurry of a predetermined viscosity without being solidified. Here, the reaction solid metal slurry can be deformed by a small force due to thixotropic properties in the state where the liquid crystal and the spherical crystal grains are mixed at an appropriate ratio at the temperature of the reaction solid region. As described above, it means a metal material which is easily formed and processed.

This reaction solidification method is called a reaction solid / semi-molding method as well as a thixoforming method, wherein the semi-melt molding method reheats a billet prepared by the reaction solid-forming method into a slurry in a semi-molten state, and then Refers to a processing method in which a slurry is cast or forged into a final product.

The reaction solid / semi-molten molding method has various advantages over the general molding method using molten metal such as casting or molten forging. For example, the slurry used in the reaction solid / semi-melt molding method has fluidity at a lower temperature than molten metal, so that the temperature of the die exposed to the slurry can be lower than that of molten metal, resulting in longer die life. Can be long. In addition, turbulence is less generated when the slurry is extruded along the cylinder, thereby reducing the incorporation of air during the casting process, thereby reducing the generation of pores in the final product. In addition, there is little solidification shrinkage, workability is improved, the mechanical properties and corrosion resistance of the product is improved, and the weight of the product is possible. Accordingly, it can be used as a new material in the automotive and aircraft industries, and electrical and electronic information communication equipment.

The conventional reaction solidification method is to make the spherical particles suitable for reaction solidification by destroying the dendrite crystal structure that is already formed by stirring at a temperature below the liquidus line when cooling the molten metal. For example, mechanical stirring, electromagnetic stirring, gas bubbling, low frequency, high frequency or electromagnetic vibration, or agitation by electric shock are used.

For example, U. S. Patent No. 3,948, 650 discloses a method and apparatus for preparing a liquid-solid mixture, in which the molten metal is cooled with vigorous stirring while solidifying. In addition, the disclosed solid metal slurry production apparatus is stirred by a stir bar while injecting a solid-liquid mixture into a vessel, which stirs the solid-liquid mixture having a predetermined viscosity to flow the resinous structure in the mixture. To crush or disperse the crushed dendritic structure. In the manufacturing method as described above, to obtain spherical crystals by grinding the dendritic crystal form already formed in the cooling process as a crystal nucleus, the cooling rate decreases and the manufacturing time increases due to the latent heat generated by the formation of the initial solidification layer And uneven crystal states due to temperature unevenness in the stirring vessel. In addition, in the case of the manufacturing apparatus, due to the limitations of mechanical agitation, the temperature distribution in the container is nonuniform, and because it operates in the chamber, the working time and subsequent processes have a very difficult limit.

U.S. Patent No. 4,465,118 discloses a method and apparatus for producing a semi-solid alloy slurry, in which a cooling manifold and a mold are sequentially provided inside an electromagnetic field applying means having a coil. The upper side is formed so that molten metal is continuously injected, and cooling water flows to the cooling manifold to cool the mold. In the method for producing a high-temperature alloy slurry, first, molten metal is injected from the upper side of the mold, and the molten metal passes through the mold to first form a solidification zone by a cooling manifold, where The magnetic field is applied by the electromagnetic field applying means, the cooling proceeds while crushing the dendritic tissue, and finally an ingot is formed from the bottom. By the way, also in such a manufacturing method and apparatus, the basic technical idea is that after solidification occurs, vibration is applied to break up the dendritic structure, which also has many problems in the above-described process and structure structure. In addition, in the case of the manufacturing apparatus, it is very difficult to control the state of the metal by forming the ingot continuously as the molten metal proceeds from the top to the bottom, or by continuously growing it, and the overall process control is difficult. In addition, there is a limit in that the temperature difference in the vicinity of the wall of the container and in the vicinity of the center of the container is severe because the container is already water-cooled at the stage before the electromagnetic field is applied.

In addition, as described below, the reaction solid / semi-melt molding method is present in various ways, but all of them have the same technical idea that the dendritic tissue is already formed and used as crystal nuclei as described above. Carry.

U.S. Patent 4,694,881 discloses a dendritic tissue formed from molten metal which is heated by heating the alloy so that all metal components in the alloy are in a liquid state, then cooling the resulting liquid metal to a temperature between the liquid and solid phase lines and then applying a shear force. Disclosed is a method of making thixotropic materials by fracture.

Japanese Laid-Open Patent Publication No. 11-33692 discloses that molten metal is injected into a container at or near the liquidus temperature or up to 50 ° above the liquidus temperature, and then at least a part of the molten metal is cooled to the liquidus temperature during cooling of the molten metal. At the time of the following, that is, the first time passing through the liquidus temperature, by applying a motion to the molten metal, for example by ultrasonic vibration, and then gradually cooled to prepare a metal slurry for reaction solid casting having a granular crystal metal structure A method is disclosed. However, also in this method, force such as ultrasonic vibration is used to break up the dendritic crystal structure formed in the initial stage of cooling. When the pouring temperature is set higher than the liquidus temperature, it is difficult to obtain a crystalline form of granules, and at the same time, it is difficult to rapidly cool the molten metal. In addition, the structure of the surface portion and the central portion becomes uneven.

In addition, in the method for forming a semi-molten metal disclosed in Japanese Patent Laid-Open No. 10-128516, the molten metal is injected into a container, and the vibration bar is deposited in the molten metal to vibrate in contact with the molten metal to vibrate in the molten metal. To give. Accordingly, the vibration force of the vibration bar is transmitted to the molten metal, thereby forming an alloy in a solid-liquid coexisting state having crystal nuclei at or below the liquidus temperature, and then cooling the molten metal in the container to a molding temperature indicating a predetermined liquidity. By holding for 30 to 60 minutes, the crystal nuclei are grown to obtain a semi-molten metal. However, the size of the crystal nuclei obtained by this method is about 100 mu m, the process time is also long, and there is a problem that it is difficult to apply to a container having a predetermined size or more.

US Pat. No. 6,432,160 discloses a method for producing a semi-molten metal slurry by precisely controlling cooling and stirring simultaneously. Specifically, after injecting molten metal into the mixing vessel, a stator assembly installed around the mixing vessel is operated to generate sufficient magnetomotive force to rapidly stir the molten metal in the vessel. The temperature of the molten metal is rapidly lowered by using a thermal jacket installed around the mixing vessel and precisely controlling the temperature of the container and the molten metal. When the molten metal is cooled, the molten metal is continuously stirred and adjusted in such a way as to provide rapid agitation when the solid fraction is low and to provide increased electromotive force as the solid phase increases.

Conventional reaction / semi-melting methods and apparatuses as described above utilize shear forces to crush the dendritic crystal forms already formed during cooling to form granular metal structures. That is, at least a part of the molten metal is applied only when the temperature is lowered below the liquidus line so as to avoid various problems such as decreasing the cooling rate and increasing the manufacturing time due to latent heat generation due to the formation of the initial solidification layer. In addition, it is difficult to obtain a uniform and fine structure as a whole due to the unevenness of the temperature in the container, and due to the temperature difference between the wall and the center of the container The nonuniformity is further increased.

The present invention is to solve the problems as described above, to obtain finer and more uniform spheroidized particles and at the same time can realize the advantages of improved energy efficiency, reduced manufacturing costs, improved mechanical properties, simplified casting process and shorter manufacturing time It is an object of the present invention to provide a die casting method and apparatus therefor.

Another object of the present invention is to produce a high quality reaction solid die casting product in a short time.

1 is a graph showing a die casting method for reaction solidification of the present invention;

2 and 3 is a schematic view showing a die casting apparatus for reaction solidification according to an embodiment of the present invention,

Figure 4 is a partial cross-sectional view showing another embodiment of the sleeve of the die casting apparatus for reaction solidification of the present invention,

Figure 5 is a schematic view showing a die casting apparatus for forming a reaction vessel according to another embodiment of the present invention,

6 and 7 is a schematic view showing a die casting apparatus for forming a reaction vessel according to another preferred embodiment of the present invention;

8 and 9 are schematic diagrams showing a die casting apparatus for reaction solidification according to another preferred embodiment of the present invention.

In order to achieve the above object, the present invention provides a metal slurry by applying an electromagnetic field to the slurry production region of the sleeve connected to the molding die having a plunger at one end and connected to the molding cavity at the other end, and injecting molten metal into the slurry production region. And forming the metal plunger and injecting the metal slurry into the molding cavity of the molding die.

According to another feature of the invention, the sleeve is disposed to be horizontal to the ground, the slurry manufacturing region of the sleeve may be a region formed by the opening and closing door and the plunger is installed in the sleeve and openable.

According to another feature of the invention, the sleeve is disposed to be inclined to the ground, the slurry manufacturing region of the sleeve may be a region formed by one end closed by the plunger.

According to another feature of the invention, the sleeve is provided so that one end is inserted into the plunger is rotated at a predetermined angle with respect to the ground, the slurry manufacturing region of the sleeve may be a region formed by one end is closed by the plunger. .

According to another feature of the invention, the sleeve is disposed perpendicular to the ground such that one end into which the plunger is inserted is toward the ground, and the slurry manufacturing region of the sleeve may be a region formed by one end closed by the plunger. have.

According to another feature of the invention, the application of the electromagnetic field may be made before injecting molten metal into the slurry manufacturing region.

According to another feature of the invention, the application of the electromagnetic field may be made at the same time as injecting molten metal into the slurry manufacturing region.

According to another feature of the invention, the application of the electromagnetic field may be made during the injection of molten metal into the slurry manufacturing region.

According to another feature of the invention, the application of the electromagnetic field may last until at least the solid phase rate of the molten metal in the slurry production region reaches 0.001 to 0.7, preferably may reach until 0.001 to 0.4 More preferably 0.001 to 0.1.

According to another feature of the present invention, the step of cooling the molten metal after the molten metal is injected into the slurry manufacturing region of the sleeve to which the electromagnetic field is applied.

According to another feature of the invention, the cooling step may include the step of cooling the molten metal until a solid phase rate of 0.1 to 0.7.

According to another feature of the invention, the cooling step may be to cool the molten metal at a rate of 0.2 ?? / s to 5.0 ?? / s.

According to another feature of the invention, the cooling step may be to cool the molten metal at a rate of 0.2 ?? / s to 2.0 ?? / s.

In order to achieve the above object, the present invention also provides a stirring portion for providing an electromagnetic field to the space portion and having a space portion therein, a sleeve provided in the space portion, in which a liquid molten metal is injected, and the sleeve A plunger for pressurizing the slurry produced by inserting it into one end thereof, and being connected to the other end of the sleeve to form a predetermined molded article, wherein a predetermined molding cavity is provided by a moving die and a fixed die, and is pressed by the plunger. It provides a die casting apparatus for reaction high molding, characterized in that the slurry comprises a molding die which is injected into the molding cavity.

According to another feature of the invention, the sleeve is arranged horizontally to the ground, the opening and closing that closes the molding die side inlet opening while pressing the plunger while the slurry is produced adjacent to the other end to which the molding die is connected The door may be further provided.

According to another feature of the invention, at least some of the sleeve may be disposed inclined with respect to the ground such that one end into which the plunger is inserted faces the ground.

According to another feature of the invention, the sleeve is provided with a first sleeve provided to be rotated at a predetermined angle with respect to the ground so that one end is inserted into the ground plunger, and the second sleeve parallel to the ground, The first sleeve is rotated and movable to be coupled to the second sleeve, and the first sleeve may be disposed in the space part.

According to another feature of the invention, the sleeve is disposed perpendicular to the ground so that one end of the plunger is inserted toward the ground, and is provided to enable the lifting movement is detachable from the molding die, the sleeve is the After the slurry is prepared, the plunger may be raised together with the forming die, and the plunger may pressurize the slurry after the sleeve is bonded.

According to another feature of the invention, the stirring unit may be to apply an electromagnetic field before the molten metal is injected into the sleeve.

According to another feature of the invention, the stirring unit may be to apply an electromagnetic field at the same time the molten metal is injected into the sleeve.

According to another feature of the invention, the stirring unit may be to apply an electromagnetic field while the molten metal is injected into the sleeve.

According to another feature of the invention, the agitating part may continue to apply the electromagnetic field until at least the solid phase rate of the molten metal in the sleeve reaches 0.001 to 0.7, preferably until it reaches 0.001 to 0.4 It may be, and more preferably may last until 0.001 to 0.1.

According to another feature of the invention, the sleeve may be further added to the temperature control device.

According to another feature of the invention, the temperature control device may be provided with at least one of a cooling device installed in the sleeve and an electric heater formed on the outer wall of the sleeve.

According to another feature of the invention, the temperature control device may cool the molten metal in the sleeve until a solid phase rate of 0.1 to 0.7.

According to another feature of the invention, the temperature control device can cool the molten metal in the sleeve at a rate of 0.2 ℃ / s to 5.0 ℃ / s.

According to another feature of the invention, the temperature control device can cool the molten metal in the sleeve at a rate of 0.2 ℃ / s to 2.0 ℃ / s.

Hereinafter, with reference to the accompanying drawings will be described in detail a preferred embodiment of the present invention.

First, with reference to Figure 1 looks at the die casting method for reaction solidification of the present invention.

Unlike the conventional techniques described above, the reaction die casting method of the present invention is to inject molten metal into a sleeve to prepare a slurry, and then inject the same into a molding die to die cast the molded article. At this time, in this invention, stirring by an electromagnetic field is performed before injection of molten metal into the said sleeve is completed. In other words, before the molten metal is injected into the sleeve, the formation of the initial dendritic tissue is blocked by the stirring by the electromagnetic field simultaneously with the molten metal into the sleeve or during the molten metal into the sleeve. In this case, ultrasonic waves may be used instead of the electromagnetic field as the stirring. This will be described in more detail as follows.

That is, an empty sleeve is arranged without pouring molten metal into a predetermined space, and an electromagnetic field is applied to a predetermined region and a slurry production region of the empty sleeve. At this time, the application of the electromagnetic field is made of an intensity capable of stirring the molten metal.

Next, as can be seen in Figure 1, the molten metal is injected into the slurry production region of the sleeve at the pouring temperature Tp, the electromagnetic field is applied to the slurry production region may be in a state where stirring is made. However, the present invention is not necessarily limited thereto, and the electric field agitation may be performed simultaneously with molten metal pouring, or electromagnetic agitation may be performed while the molten metal is pouring.

By performing electromagnetic agitation before the injection of the molten metal into the sleeve is completed, the molten metal does not grow from the initial solidification layer in the inner sleeve of the low temperature sleeve into the dendritic structure, and thus the fine crystals throughout the slurry manufacturing region. The nuclei are generated at the same time, the entire molten metal in the slurry manufacturing region can be rapidly cooled directly below the liquidus temperature to generate a plurality of crystal nuclei at the same time.

This is due to active initial agitation by applying an electromagnetic field before or at the same time as injecting the molten metal into the slurry manufacturing zone, and the molten metal inside and the molten metal on the surface are well stirred, so that the heat transfer in the molten metal occurs quickly, and the inner wall of the sleeve This is because the initial solidification layer formation at is suppressed. In addition, convective heat transfer between the well-stirred molten metal and the low temperature inner sleeve wall increases, thereby rapidly cooling the temperature of the entire molten metal. That is, the injected molten metal is dispersed into the dispersed particles by electromagnetic field stirring at the same time as the injection, and the dispersed particles are evenly distributed in the sleeve as crystal nuclei, so that a temperature difference does not occur throughout the slurry manufacturing region. On the other hand, according to the prior arts, the injected molten metal is brought into contact with the inner sleeve of the low temperature sleeve and grows into dendritic crystals in the initial solidification layer in the inner sleeve wall by rapid convective heat transfer.

This principle may be explained with reference to the latent heat of solidification, that is, no initial solidification of the molten metal at the inner wall surface of the sleeve occurs, so that no latent heat of solidification occurs, so that cooling of the molten metal is only performed by the molten metal. It is possible to release only the amount of heat corresponding to the specific heat of (only about 1/400 of the latent heat of solidification). Accordingly, the molten metal in the slurry manufacturing region is uniformly and rapidly reduced in temperature throughout the center from the wall of the sleeve, without forming a dendrite crystal which is an initial solidification layer that is often generated in the inner wall of the sleeve as in the prior art. Indicates. The time it takes is only a short time of about 1 to 10 seconds after the injection of molten metal. As a result, a large number of crystal nuclei are uniformly generated throughout the molten metal in the slurry manufacturing region, and the distance between the crystal nuclei becomes very short due to the increase in the nuclei formation density, and thus dendritic crystals do not form and grow independently. To form.

The same is true when an electromagnetic field is applied while molten metal is being poured. In the case where an electromagnetic field is applied while molten metal is being poured, although the initial solidification layer is formed on the inner wall of the sleeve, the initial solidification layer no longer grows into the dendritic structure by stirring the electromagnetic field during the injection process. You will not lose. The effects thereafter are as described above.

At this time, the molten metal pouring temperature Tp is preferably maintained at a temperature between the liquidus temperature to the liquidus + 100 ℃ (melt superheat degree, melt superheat = 0 ℃ ~ 100 ℃). As described above, since the entire inside of the slurry manufacturing region containing the molten metal is uniformly cooled, it is not necessary to cool the liquidus temperature near the liquidus temperature before injecting the molten metal into the sleeve, and the temperature higher than the liquidus temperature is about 100 ° C. This is because it can be maintained. On the other hand, in the conventional method of applying the electromagnetic field to the container when the molten metal is injected into the slurry production container and a part of the molten metal is below the liquidus line, the initial solidification layer is formed on the wall of the container, and the latent heat of solidification is generated. Since the latent heat of coagulation is about 400 times the specific heat, it takes a lot of time for the temperature of the molten metal of the entire container to drop. Therefore, in this conventional method, it was common to cool the temperature of the molten metal to a temperature of about 50 ° C. above the liquidus level or to inject it into a container. Therefore, at this time, it is necessary to wait until the temperature of the injected molten metal reaches an appropriate temperature, which is very difficult in the actual process.

In addition, in the present invention, the end point of the electromagnetic field agitation is, as shown in FIG. 1, when the temperature of the molten metal in the sleeve is at least a portion, that is, below the liquidus temperature T ₁ , that is, After a predetermined crystal nucleus is formed at a solid phase rate of about 0.001, there is no big problem even if the electromagnetic field agitation is terminated at any time. That is, the electromagnetic field agitation may be applied until the molten metal is injected into the slurry manufacturing region of the sleeve, the molten metal is cooled, and the molten metal is injected into the molding die according to subsequent pressurization. This is because the magnetic field agitation at the stage of crystal grain growth around the crystal nuclei does not affect the properties of the metal slurry to be produced because the nuclei are evenly distributed throughout the slurry manufacturing region of the sleeve.

However, the above-mentioned electromagnetic stirring may be applied only during the manufacture of the metal slurry in the sleeve, and therefore, at least until the solid phase rate of the molten metal reaches any time of 0.001 to 0.7, and in terms of energy efficiency, It can last at least until the solid phase rate of the molten metal in the slurry production zone is 0.001 to 0.4, more preferably until the solid phase rate of the molten metal is 0.001 to 0.1.

On the other hand, after the molten metal is injected into the slurry production region to form crystal nuclei with a uniform distribution, the slurry production region is cooled to accelerate the growth of the generated crystal nuclei. Therefore, this cooling step may be performed when the molten metal is injected into the slurry production region. As described above, the electromagnetic field may be continuously applied even during this cooling step.

On the other hand, the cooling step may be continued until the step of injecting the slurry into the molding die according to the pressurization, according to a preferred embodiment of the present invention, the molten metal is cooled to a point (t2) until the solid phase rate of 0.1 to 0.7 In this case, the cooling rate of the molten metal may be about 0.2 ° C./sec to 5.0 ° C./sec, which may also be 0.2 ° C./sec to 2.0 depending on the distribution of crystal nuclei and fineness of particles. It can also be set to ° C / sec.

According to this method, a metal slurry in a solid state of a solid state having a predetermined solid phase rate can be prepared, and it can be directly pressurized and injected into a molding cavity of a molding die to diecast.

According to the method as described above, it is possible to significantly shorten the time to prepare the metal slurry in the reaction solid state, from the time of injection of the molten metal into the sleeve into a metal material in the form of a metal slurry with a solid phase of 0.1 to 0.7 The time required to form is only 30 seconds to 60 seconds. By die casting using the prepared metal slurry, a molded article having a uniform and dense spherical crystal structure can be obtained.

This die-casting method for reaction solidification can be applied to both the horizontal horizontal to the ground, the inclined slope to the ground, the vertical perpendicular to the ground.

If the sleeve is disposed to be horizontal to the ground, the slurry manufacturing region of the sleeve may be a region formed by the opening / closing door and the plunger which is installed in the sleeve to open and close, and the sleeve is inclined to the ground. If present, the slurry manufacturing region of the sleeve may be a region where one end is closed by the plunger. In addition, when the sleeve is disposed perpendicular to the ground such that one end into which the plunger is inserted is toward the ground, the slurry manufacturing region of the sleeve may be a region formed by closing one end of the sleeve by the plunger. Each structure of the die casting apparatus according to the arrangement of the sleeve will be described later.

The die casting method for reaction solidification as described above may be realized by the preferred embodiment of the present invention according to FIGS. 2 and 3.

As shown in FIG. 2, the die casting apparatus for reaction solidification according to an exemplary embodiment of the present invention includes a space portion 12 therein, and an electromagnetic field applying coil device 11 includes the space portion 12. A stirring portion 1 provided to surround the sleeve, a sleeve 2 provided in the space portion 12 in the stirring portion 1, and a pressurizing plunger 3 inserted into one end of the sleeve 2; And a forming die 4 connected to the other end of the sleeve 2.

The stirring part 1 has a space part 12 inside, and the coil device 11 for electromagnetic field application is arrange | positioned so that this space part 12 may be enclosed. The space 12 and the electromagnetic field applying coil device 11 are fixed by a separate frame structure (not shown). The electromagnetic field applying coil device 11 is provided to radiate an electromagnetic field of a predetermined intensity toward the space portion 12, and electromagnetic stirring of the molten metal injected into the sleeve 2 accommodated in the space portion 12, It is electrically connected to a control unit (not shown), and the strength and operating time thereof are adjusted. The electromagnetic field applying coil device 11 may be applied to any coil device that can be used for normal electromagnetic stirring. Such a stirring unit may be provided to perform ultrasonic stirring in addition to the electromagnetic field.

Meanwhile, as shown in FIG. 2, the electromagnetic field applying coil device 11 has a center of the mouthpiece 21 formed in the sleeve 2, and thus, the mouthpiece fixture 23 extending from the mouthpiece 21. Are excreted around. Accordingly, the molten metal injected into the sleeve 2 is to be thoroughly stirred from the stage of injection.

The sleeve 2 according to the present invention combines the function of a slurry production vessel for reacting molten metal into a slurry by electromagnetic field stirring and for guiding the produced slurry to the forming die 4.

The plunger 3 is inserted into one end of the sleeve 2, and the other end is connected to the forming die 4. The sleeve 2 is normally provided and installed in the space 12 of the stirring part 1. do. A spout 21 is formed in the upper portion of the sleeve 2 so that molten metal can be injected therein, and a funnel-shaped pouring jig 22 is stirred in the sputter 21 to facilitate pouring from the ladle 5. The portion 1 extends outward.

The sleeve 2 may be provided with a metal material, or may be provided with an insulating material such as alumina or aluminum nitride. When provided with a metal material, it is preferable to use the thing whose temperature is higher than the temperature of the molten metal accommodated. Although not shown in the drawings, a separate thermocouple may be embedded, and the thermocouple may be connected to a controller (not shown) to transmit temperature information to the controller.

In a preferred embodiment of the invention as seen in FIGS. 2 and 3, the sleeve 2 is arranged horizontally on the ground, to react the molten metal injected through the spout 21 into a slurry for reaction. The opening and closing door 23 is provided at a position adjacent to the other end to which the forming die 4 is connected. The opening / closing door 23 is closed while the slurry is produced in the sleeve 2, and is opened when the plunger 3 pressurizes the produced solid slurry. Thus, one side of the sleeve 2 is closed by the plunger 3, the other side is closed by the opening and closing door 23 so that the sleeve can perform the function as a slurry production vessel.

In addition, the sleeve 2 may be formed to accommodate only molten metal, as shown in FIGS. 2 and 3, but may further include a temperature controller 24, as shown in FIG. 4. have. The temperature control device 24 is a cooling device and a heating device can be applied alone or in combination, according to a preferred embodiment of the present invention, the cooling device, for example, the cooling water pipe 25 in the form of a water jacket It may be to surround the outside of the sleeve 2, the heating device may be an electric heater (not shown) formed on the outside of the sleeve (2). The coolant pipe 25 is installed in a separate fixing block 26 on the outer wall of the sleeve 2. And of course, the sleeve 2 may be embedded with a thermocouple.

The molten metal received in the sleeve by such a coolant pipe 25 and an electric heater (not shown) can be cooled at an appropriate rate. Of course, the sleeve 2 and its temperature control device 24 as seen in FIG. 4 can be applied as is to all embodiments of the present invention described below.

On the other hand, the plunger 3 inserted into one end of the sleeve 2 is connected to a separate pressurizing device (not shown) to reciprocate the piston in the sleeve 2, the reaction slurry in the sleeve 2 After the manufacture of the mold is completed, the slurry is injected into the molding die 4 by advancing in the direction of the molding die 4.

The forming die 4 connected to the other end of the sleeve 2 comprises a moving die 41 and a fixed die 42. The movable die 41 and the stationary die 42 meet to form a molding cavity 43 having a predetermined shape, and the stationary die 42 is injected into the molding cavity 43 so that a slurry in a solid state is injected. The injection port 44 is processed. These moving dies 41 and the stationary die 42 are respectively installed on the support plates 45a and 45b, which are attached to the machine facility in which the die casting apparatus according to the present invention is installed. The moving die 41 and the fixed die 42 are supported. The moving die 41 is separated from the fixed die 42 when the molding is completed, so that the molded article formed in the molding cavity 43 can be separated.

Next, with reference to Figures 1 to 3 will be described the operation of the die casting apparatus for reaction solidification according to a preferred embodiment of the present invention configured as described above.

First, as shown in FIG. 2, the electromagnetic field is applied at a predetermined frequency and intensity into the space 12 by the coil device 11 for applying the electromagnetic field in the stirring unit 1. The voltage, frequency, and intensity of the applied electromagnetic field may be 250V, 60Hz, and 500Gauss, respectively, but are not limited thereto.

In this state, the molten metal melted in a separate furnace is transferred by an injection vessel 5 such as a ladle and injected into the slurry production zone in the sleeve 2 under the influence of the electromagnetic field. At this time, the furnace and the sleeve may be directly connected to allow molten liquid molten metal to be directly injected into the sleeve. In addition, the said molten metal at this time may be liquidus + 100 degreeC as mentioned above.

As such, when the molten metal, which is completely molten and liquid, is injected into the sleeve 2 in which electromagnetic stirring is in progress, fine recrystallized particles are distributed throughout the sleeve 2, and the recrystallized particles grow rapidly to form a dendritic structure. No generation will occur.

As described above, the electromagnetic field may be applied at the same time as the injection of the molten metal or may be applied during the injection of the molten metal.

In addition, the application of the electromagnetic field can be performed until the slurry is injected into the molding cavity as described above. Thus, application of the electromagnetic field can last at least until the solid phase rate of the molten metal is 0.001 to 0.7. However, for energy efficiency, it is preferable to continue until the solid phase rate becomes 0.001 to 0.4 after the injection of molten metal, and more preferably, it can be continued until the solid phase rate becomes 0.001 to 0.1. This time can be determined by experiment in advance, and thus applying the electromagnetic field for a fixed time.

After the application of the electromagnetic field is terminated or while the application of the electromagnetic field is continued, the sleeve 2 is cooled at a predetermined rate until a solid phase rate of 0.1 to 0.7 is produced to produce a reactive metal slurry. At this time, the cooling rate is controlled by a temperature control device installed outside the sleeve 2 may be a rate of 0.2 ℃ / sec to 5.0 ℃ / sec, more preferably 0.2 ℃ / sec to 2.0 ℃ / sec Can be speed.

After producing the reaction solid metal slurry, the opening / closing door 23 is opened, and as shown in FIG. 3, the slurry is pressurized using the plunger 3 and injected into the forming die 4. The slurry pressurized by the plunger 3 is injected into the molding cavity 43 through the inlet 44 of the molding die 4, where it is rapidly cooled to produce a molded article corresponding to the shape of the molding cavity 43. Will be done. After the molding is completed, the moving die 41 is retracted to separate the molding die 4, thereby taking out the molded article from the molding cavity 43.

Thus, according to the die casting apparatus for reaction solidification according to a preferred embodiment of the present invention, not only a molded product having a fine and uniform structure can be obtained by a simple method, but also the time for preparing the reaction solid metal slurry can be significantly shortened. The overall process time can be reduced, resulting in increased energy savings and increased productivity.

FIG. 5 shows a die casting apparatus for reaction solidification according to another exemplary embodiment of the present invention, which is different from the above embodiment in that the sleeve 2 is grounded so that one end of the plunger 3 is inserted into the ground. To be inclined relative to Hereinafter, description will be made mainly on the parts that are distinguished from the above-described embodiment.

The die casting apparatus for reaction solidification according to another preferred embodiment of the present invention is arranged such that the sleeve 2 is inclined with respect to the ground, as shown in FIG. There is no need to have an opening and closing door for blocking. In other words, the molten metal injected through the spout 21 is accumulated in the vicinity of the plunger 3 of the sleeve 2 is disposed obliquely, it is not necessary to provide a separate opening and closing door in the sleeve (2). In this case, however, it may be preferable to provide a door opening and closing door that can block the mouth opening 21 when the slurry in the sleeve 2 is pressurized by the plunger 3. The angle of inclination of the sleeve 2 may be adjusted in accordance with the design conditions, but any angle may be sufficient as molten metal may accumulate inside the sleeve 2 depending on the angle of inclination.

As the sleeve 2 is formed to be inclined, as shown in FIG. 5, the forming die 4 connected to the other end of the sleeve 2 is also disposed to be inclined as a whole. However, this arrangement of the forming die 4 obliquely may create limitations in its application with the whole machine. As can be seen in FIGS. 6 and 7, the forming die 4 is placed horizontally on the ground. It can be formed into a structure for operating only the slurry manufacturing region of the sleeve.

That is, as can be seen in FIGS. 6 and 7, the sleeve 2 can be rotated at a predetermined angle θ, and the second sleeve fixed to the forming die 4 ( It divides into 24 and arrange | positions the rotating 1st sleeve 23 to the space part 12 of the stirring part 1. The inside of this first sleeve 23 becomes a slurry production area. As shown in FIGS. 6 and 7, the first sleeve 23 and the second sleeve 24 are coupled to one side of end portions facing each other such that the first sleeve 23 has a predetermined angle θ at the center thereof. It is preferable that the rotation angle θ be within 90 degrees. When the first sleeve 23 is inclined at an angle of 90 degrees with respect to the ground as shown in FIG. 6, molten metal is injected therebetween to prepare a slurry, and after the slurry production is completed, as shown in FIG. And the second sleeve 24 are combined, and the plunger 3 is pressurized to inject the slurry into the molding cavity 43 of the molding die 4 for molding. Therefore, in this apparatus, a separate hot water ball is not necessary.

8 and 9 show a die casting apparatus for reaction solidification according to another preferred embodiment of the present invention. As can be seen in FIGS. 8 and 9, the sleeve 2 is disposed perpendicular to the ground. do. The sleeve 2 is disposed perpendicular to the ground such that one end into which the plunger 3 is inserted is directed toward the ground, and is connected to a separate driving device (not shown) so as to allow the lifting movement. And this sleeve 2 has a structure which can be attached or detached from the shaping | molding die 4.

In another preferred embodiment of the present invention, the sleeve 2 may be provided with a sleeve body 2a, a movable sleeve 2b, and a fixed sleeve 2c. The sleeve body 2a is formed such that the plunger 3 is inserted into the lower end portion and the molten metal is injected into the open upper end portion. The lower end of the sleeve body (2a) is coupled to the movable sleeve (2b) connected to a separate drive (not shown). As described later, the movable sleeve 2b functions to push up the sleeve body 2a to be bonded to the fixing sleeve 2c of the fixing die 42 after the slurry is manufactured. The sleeve body 2a It may be formed integrally with. The sleeve body 2a is disposed to be located in the space portion 12 of the stirring portion 1 provided on the support 13, and an electromagnetic field applying coil device 11 is installed to surround the space portion 12. .

On the other hand, the shaping die 4 is also vertically disposed so that the injection hole 44 faces the sleeve 2 in correspondence to the vertical arrangement of the sleeve 2. At this time, the lower end is stepped downwardly so that the sleeve body 2a is inserted into the fixing die 42, and the fixing sleeve 2c and the fixing sleeve 2c are coupled to the sleeve body 2a. Support member 46 for supporting and fixing the sleeve body (2a) coupled to the) is installed.

According to another preferred embodiment of the present invention configured as described above, first, the position of the sleeve body 2a in the space portion 12 in a state in which the sleeve body 2a is separated from the forming die 4 as shown in FIG. 8. Let's do it. And the electromagnetic field is applied to the space part 12 by the stirring part 1, and molten metal is inject | poured into the sleeve main body 2a by the injection container 5. At this time, the lower end of the sleeve body 2a is closed by the plunger so that the sleeve body 2a functions as a container.

After the molten metal is injected into the sleeve body 2a, the molten metal is cooled to prepare a reaction solid metal slurry. This is the same as described above.

After slurry production is complete, the movable sleeve 2b and the plunger 3 are raised to allow the sleeve body 2a to engage the fixed sleeve 2c installed in the forming die 4, as shown in FIG. 9. The plunger 3 is accelerated and raised to inject a slurry into the molding cavity of the molding die 4 to perform molding.

According to the die casting apparatus for reaction solidification according to another preferred embodiment of the present invention, there is no need to install a separate opening and closing door in the sleeve, and the sleeve can be used as a slurry production container, thereby further simplifying the reaction solidification. It becomes possible to do it.

As described above, the die casting method for apparatus for solidification and the apparatus of the present invention are various metals / alloys such as aluminum or alloys thereof, magnesium or alloys thereof, zinc or alloys thereof, copper or alloys thereof, or iron or the like. Of course, it can be applied universally to reaction solidification methods such as alloys.

As described above, according to the present invention, the following effects can be obtained.

First, a molded article having a uniform and fine spherical structure as a whole can be obtained.

Second, even a short time of stirring at a higher temperature than the liquidus can significantly increase the nucleation density on the sleeve wall to realize spheroidization of the particles.

Third, improvement of the mechanical properties of the manufactured molded article can be realized.

Fourth, since the electromagnetic stirring time can be greatly shortened, less energy is required for stirring.

Fifth, the overall process can be simplified, and the product molding time can be shortened, thereby improving productivity.

In the present specification, the present invention has been described with reference to limited embodiments, but various embodiments are possible within the spirit of the present invention. In addition, although not described, equivalent means will also be referred to as incorporated in the present invention. Therefore, the true scope of the present invention will be defined by the claims.

Claims (31)

Applying an electromagnetic field to a slurry manufacturing region of the sleeve having a plunger inserted at one end and connected to a molding die having a molding cavity at the other end, and injecting molten metal into the slurry manufacturing region to form a metal slurry; And Compressing the plunger and injecting the metal slurry into a molding cavity of the molding die. The method of claim 1, And the sleeve is disposed to be horizontal to the ground, and the slurry manufacturing region of the sleeve is a region formed by the opening / closing door and the plunger installed in the sleeve to open and close. The method of claim 1, The sleeve is disposed so as to be inclined with respect to the ground such that one end into which the plunger is inserted is directed toward the ground, and the slurry manufacturing region of the sleeve is a region formed by closing one end by the plunger. . The method of claim 1, And the sleeve is provided such that one end of the plunger is rotated at a predetermined angle with respect to the ground, and the slurry manufacturing region of the sleeve is an area formed by closing one end of the plunger by the plunger. The method of claim 1, The sleeve is disposed vertically with respect to the ground such that one end into which the plunger is inserted is directed toward the ground, and the slurry manufacturing region of the sleeve is a region formed by closing one end by the plunger. . The method according to any one of claims 1 to 5, The application of the electromagnetic field is a reaction casting die casting method, characterized in that before the injection of molten metal into the slurry manufacturing region. The method according to any one of claims 1 to 5, The application of the electromagnetic field is a die casting method for reactive solidification, characterized in that at the same time as the molten metal is injected into the slurry manufacturing region. The method according to any one of claims 1 to 5, The application of the electromagnetic field is carried out during the injection of molten metal into the slurry production region die casting method for reaction molding. The method according to any one of claims 1 to 5, The application of the electromagnetic field lasts at least until the solid phase rate of the molten metal in the slurry production zone reaches 0.001 to 0.7. The method of claim 9, The application of the electromagnetic field lasts at least until the solid phase rate of the molten metal in the slurry production zone reaches 0.001 to 0.4. The method of claim 10, The application of the electromagnetic field lasts at least until the solid phase rate of the molten metal in the slurry production zone reaches 0.001 to 0.1. The method according to any one of claims 1 to 5, And cooling the molten metal after injecting molten metal into the slurry manufacturing region of the sleeve to which the electromagnetic field is applied. The method of claim 12, The cooling step is a reaction casting die casting method comprising the step of cooling the molten metal until a solid phase rate of 0.1 to 0.7. The method of claim 12, The cooling step is a die casting method for reaction solidification, characterized in that for cooling the molten metal at a rate of 0.2 ℃ / s to 5.0 ℃ / s. The method of claim 14, The cooling step is a die casting method for reaction solid molding, characterized in that for cooling the molten metal at a rate of 0.2 ℃ / 2.0 to 2.0 ℃ / s. A stirring unit having a space inside and applying an electromagnetic field to the space; A sleeve provided in the space part and into which a molten metal of a liquid is injected; A plunger pressurizing the prepared slurry inserted into one end of the sleeve; And A molding die connected to the other end of the sleeve to form a predetermined molded article, the molding die having a predetermined molding cavity by a moving die and a fixed die, wherein the slurry is injected into the molding cavity by pressurization of the plunger; Die casting apparatus for reaction molding, characterized in that. The method of claim 16, The sleeve is disposed to be horizontal to the ground, and adjacent to the other end connected to the molding die further comprises an opening and closing door for closing the molding die side inlet while the slurry is manufactured and open when the plunger is pressed. Die casting apparatus for reaction high molding. The method of claim 16, At least a portion of the sleeve is die casting apparatus for reaction solidification, characterized in that the one end is inserted inclined with respect to the ground so that the one end is inserted into the ground. The method of claim 16, The sleeve is provided with a first sleeve provided to be rotated at a predetermined angle with respect to the ground so that one end into which the plunger is inserted is directed to the ground, and a second sleeve parallel to the ground, wherein the first sleeve is rotated to form the second sleeve. It is movable to be coupled to a sleeve, the die casting apparatus for the reaction molding, characterized in that the first sleeve is disposed in the space portion. The method of claim 16, The sleeve is disposed perpendicular to the ground such that one end into which the plunger is inserted is directed toward the ground, and is provided to be capable of lifting and lowering with the forming die, wherein the sleeve is with the plunger after the slurry is manufactured. A die casting apparatus for reaction solidification, wherein the plunger pressurizes the slurry after the sleeve is raised to be bonded to the molding die. The method according to any one of claims 16 to 20, The stirring part die casting apparatus for forming a reaction solid, characterized in that for applying an electromagnetic field before the molten metal is injected into the sleeve. The method according to any one of claims 16 to 20, The stirring unit is a reaction casting die casting device, characterized in that the molten metal is injected into the sleeve and at the same time apply an electromagnetic field. The method according to any one of claims 16 to 20, The stirring unit is a reaction casting die casting apparatus, characterized in that for applying an electromagnetic field while the molten metal is injected into the sleeve. The method according to any one of claims 16 to 20, And wherein the stirring unit maintains the application of the electromagnetic field until at least the solid phase rate of the molten metal in the sleeve reaches 0.001 to 0.7. The method of claim 24, And wherein the stirring unit continues to apply the electromagnetic field until at least the solid phase rate of the molten metal in the sleeve reaches 0.001 to 0.4. The method of claim 25, And wherein the stirring unit maintains the application of the electromagnetic field until at least the solid phase rate of the molten metal in the sleeve reaches 0.001 to 0.1. The method according to any one of claims 16 to 20, The sleeve is die-casting apparatus for reaction molding, characterized in that the temperature control device is further added. The method of claim 27, And the temperature control device is provided with at least one of a cooling device installed in the sleeve and an electric heater formed on the outer wall of the sleeve. The method of claim 27, And the temperature control device cools the molten metal in the sleeve until it reaches a solid phase rate of 0.1 to 0.7. The method of claim 27, The temperature control device is a die casting apparatus for reaction solidification, characterized in that for cooling the molten metal in the sleeve at a rate of 0.2 ℃ / s to 5.0 ℃ / s. The method of claim 30, The temperature control device is a die casting apparatus for reaction solidification, characterized in that for cooling the molten metal in the sleeve at a rate of 0.2 ℃ / 2.0 to 2.0 ℃ / s.