JP2007512146A - Semi-solid metal slurry manufacturing method and apparatus - Google Patents

Abstract

The present invention relates to a method and an apparatus for producing a semi-solid metal slurry, and more particularly, in order to be able to produce a semi-solid metal slurry into a uniform spheroidized structure through a simple process.
In a method for producing a semi-solid metal slurry having a uniform spheroidized structure, a molten metal feeding stage for feeding molten metal to a melting furnace; and an electromagnetic field is applied to the molten metal fed to the melting furnace by an electronic stirrer. An electromagnetic field stirring stage that suppresses dendritic tissue growth at the same time as applying and removing temperature deviation of the molten metal; and an inert atmosphere by rapidly cooling the specific heat and latent heat of the molten metal discharged from the melting furnace in a cooling section A cooling step that prevents oxidation and prevents dendritic structures from being formed; the cooled slurry is uniformly distributed in the slurry storage container through the inclined guide member. The present invention relates to a method and an apparatus for producing a semi-solid metal slurry, characterized in that it includes a slurry storage step for storing the slurry.

Description

Detailed Description of the Invention

〔Technical field〕
The present invention relates to a method and an apparatus for producing a semi-solid metal slurry, and more particularly, to a semi-solid metal capable of producing a semi-solid metal slurry into a uniform spheroidized structure through a simple process. The present invention relates to a slurry production method and apparatus.

[Background Technology]
In general, Semi-Solid Metal Forming technology is a method of forming a metal or a metal-based composite material in a temperature range in which a liquid phase and a solid phase coexist. It is a new molding technology that complements the disadvantages of the forging technology that forms in the solid state and maximizes the advantages. Many researches and technical developments have been carried out for practical application, and effective semi-solid metal molding For this purpose, it is important to produce a slurry in which the initial structure is free of dendritic structure and spherical particles are uniformly distributed.

  For this reason, in the existing method and apparatus for producing a semi-solid metal slurry using a semi-solid metal forming method, various methods and various types of apparatuses have been devised and used. As a typical example, a method in which a dendritic structure is broken into a spherical shape by shearing stress due to mechanical or electromagnetic stirring while the molten metal is solidified is mainly used.

  However, in the conventional method and apparatus for producing a semi-solid metal slurry, shear force is used to pulverize the dendritic crystal form already formed in the cooling process into a granular metal structure, that is, When the temperature of a part of the molten metal drops below the liquidus, a force such as vibration is applied for the first time, so the initial solidified layer or the metal structure formed thereby also has a non-uniform temperature in the container. It is difficult to obtain a uniform and fine structure as a whole, and if the injection temperature of the molten metal into the container is not adjusted, the non-uniformity of the structure will be further increased due to the temperature difference between the wall surface and the center of the container. Has a problem.

  In order to solve such problems, conventionally, as shown in FIG. 7, an inclined angle is given to the wall surface of the container as shown in FIG. The molten metal injection step 110 and the cooling step 120 are performed immediately on the outer wall of the container as shown in (b) and cooled by air in a cooling furnace or the like to reduce the internal and external temperature deviations. In the air cooling performed on the outer wall of the container, a dendritic structure is formed on the outer wall of the container, and when this is again raised to an appropriate temperature via high-frequency heating as in (c), the principle of diffusion The high-frequency heating process 130 in which the homogenization of the structure is performed while the alpha phase grows and the deviation of the external temperature becomes equal, and the semi-solid metal slurry thus produced is shown in (d). Need to be separated from the container as A forming step 140 is performed to form the film.

  However, even in such a method, the process of producing the semi-solid metal slurry is performed separately for each process, which not only makes the operation cumbersome, but also requires a long time, as well as productivity. There was a problem of a significant decrease.

[Disclosure of the Invention]
Therefore, the present invention has been devised to solve the conventional problems as described above, and its purpose is to produce a semi-solid metal slurry into a uniform spheroidized structure through a simple process. It is in providing the manufacturing method which can be performed.

  Another object of the present invention is to provide a manufacturing apparatus that allows a semi-solid metal slurry to be easily manufactured into a uniform structure having a spheroid shape with a simple structure unified from supply to molding. There is.

  Another object of the present invention is to enable the temperature deviation of the molten metal supplied to the melting furnace to be minimized.

  Another object of the present invention is to enable rapid cooling to the molten metal to be performed more efficiently.

  Another object of the present invention is to allow the stored slurry to be evenly distributed.

  In order to achieve the above object, the present invention provides a method for producing a semi-solid metal slurry having a uniform spheroidized structure, and a molten metal feeding step of feeding molten metal to the melting furnace; An electromagnetic field is applied to the molten metal fed to the molten metal by an electronic stirrer to remove the temperature deviation of the molten metal, and at the same time, an electromagnetic field stirring stage to suppress dendritic tissue growth; and the molten metal discharged from the melting furnace A cooling stage in which specific heat and latent heat are rapidly cooled in a cooling section to prevent oxidation in an inert atmosphere so that a dendritic structure is not formed; and through a guide member installed with the cooled slurry inclined And a slurry storage step for storing the material falling uniformly in the slurry storage container.

  The method further includes a temperature adjustment step of adjusting an internal temperature by a temperature controller according to a temperature of the molten metal fed into the melting furnace and an atmospheric temperature in the melting furnace.

  A melting furnace formed by a refractory material so that molten metal is fed into and discharged from a housing formed in an upper part of the apparatus for producing a spheroidized uniform structure semi-solid metal slurry; An electronic stirrer installed so that an electromagnetic field is formed on the outside of the furnace by applying electricity; a cooler installed at the bottom of the discharge path of the melting furnace and installed so that the discharged molten metal can be rapidly cooled; A guide member installed at an angle so as to guide the cooled slurry to the lower part of the support frame installed at the lower part of the cooler; and the falling slurry is uniformly installed at the lower part of the guide member. It is comprised with the storage part which stores so that it may be distributed.

  The melting furnace is provided with a temperature controller for adjusting the internal temperature according to the atmospheric temperature in the melting furnace and the temperature of the molten metal.

  The temperature controller includes a temperature sensor and a heating member that generates heat in response to a signal from the temperature sensor.

  In the cooler, a space is formed between an inner wall and an outer wall constituting the cooler, and a passage connected to a discharge path of a melting furnace is formed at an inner center of the inner wall, and one side of the outer wall is formed. A supply connecting pipe connected to the space is formed on the inner wall, and a plurality of injection holes connected to the space are formed on the inner wall.

  The electronic stirrer is installed outside the melting furnace and the cooler.

  The storage unit includes a slurry storage container in which slurry is received, and swirling means that swirls so that the slurry falling in the slurry storage container can be uniformly stored.

  The swivel means swivels the slurry storage container with a constant trajectory according to the input program.

  The slurry storage container is a ceramic material having a low thermal conductivity.

[Best Mode for Carrying Out the Invention]
Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

  FIG. 1 is a schematic block diagram showing the manufacturing stage of the present invention.

As shown in the figure, not only the requirements of complex shapes and number accuracy, molding processability, heat treatment, bubble defect pressure resistance test and productivity are excellent, but also wear resistance, stretch ratio, hardness and tensile strength. In a method for producing a semi-solid metal slurry having an excellent, non-directional, uniform spheroidized structure,
The present invention includes a molten metal feeding step S1 for feeding molten metal to a melting furnace through a known ladle inlet;
By applying an electromagnetic field to the molten metal fed to the melting furnace with an electronic stirrer, temperature deviation is removed so that the temperature of the molten metal can be uniformly distributed, and at the same time, electromagnetic field stirring is performed to suppress dendritic tissue growth. Stage S2;
A cooling step S3 in which the specific heat and latent heat of the molten metal discharged from the melting furnace are rapidly cooled in a cooling section to prevent oxidation in an inert atmosphere and to prevent the formation of a dendritic structure;
It shows that the cooled slurry includes a slurry storage step S4 for storing the slurried slurry so as to be evenly distributed in the slurry storage container through a guide member installed at an inclination. is there.

  Further, the temperature adjustment is performed by adjusting the internal temperature with a temperature controller that senses the temperature according to the temperature of the molten metal fed into the melting furnace and the atmospheric temperature in the melting furnace and generates heat to adjust the temperature. Step S1a is further included. In particular, when the molten metal is re-supplied to the melting furnace, the initial heat loss can be minimized by the condition that the temperature can be adjusted to a constant temperature in the temperature adjusting step.

  FIG. 2 is a schematic longitudinal sectional view showing the main part of the manufacturing apparatus of the present invention.

As shown in the figure, requirements for complex shapes and numerical accuracy, molding processability, heat treatment, bubble defect pressure resistance test and productivity are not only excellent, but also wear resistance, stretch ratio, hardness and tensile strength are excellent In an apparatus for producing a non-directional, uniform spheroidized semi-solid metal slurry,
The present invention includes a melting furnace 10 formed of a refractory material having a low thermal conductivity so that molten metal is fed into and discharged from a housing 1 formed at the top via a known ladle inlet;
An electromagnetic field is formed outside the melting furnace by applying electricity so that the temperature of the molten metal fed and injected into the melting furnace has a uniform distribution and at the same time suppresses dendritic tissue growth. A normal electronic stirrer 20 installed as follows;
A cooler 30 installed so as to rapidly cool the specific heat and latent heat of the molten metal discharged to the lower part of the discharge passage 12 of the melting furnace 10 to prevent oxidation in an inert atmosphere;
A funnel-shaped guide member 40 installed on the support frame 42 installed at the lower part of the cooler so as to be inclined so as to guide the slurry cooled by the cooler to the lower part;
It shows that it is comprised by the storage part 50 installed in the lower part of the said guide member, and storing so that the slurry falling from a guide member may be distributed uniformly.

  The melting furnace 10 includes a normal temperature sensor (not shown) and a known heating member (not shown) such as a heating coil that generates heat in response to a signal from the temperature sensor. It is preferable to provide a known temperature controller 60 that adjusts the internal temperature according to the atmospheric temperature in the melting furnace and the temperature of the melt.

  As a result, it becomes possible to minimize the temperature change of the inside of the melting furnace to which the molten metal is injected and the molten metal to be injected, so that it is possible to maintain the optimum state for producing the semi-solid metal slurry. It will be possible.

  In particular, the temperature controller provided in the melting furnace also has a role of minimizing the loss of initial heat when the molten metal is re-supplied.

  In the cooler 30, a space 35 is formed between an inner wall 34 and an outer wall 36 forming the cooler 30, and a passage 32 connected to the discharge path of the melting furnace is formed at the inner center of the inner wall. A supply connection pipe 36a connected to the space portion is formed on one side of the outer wall, and a plurality of injection holes 34a connected to the space portion are formed on the inner wall and pass through the passage. It is preferable that a coolant is supplied to the molten metal to be rapidly cooled.

  The electronic stirrer 20 is installed so as to cover the outside of the melting furnace 10 and the cooler 30, and is generated by an electromagnetic field in the process of being cooled through the cooler as well as the molten metal in the melting furnace. It is preferable that a dendritic structure is not formed by the stirring force.

  The storage unit 50 includes a slurry storage container 52 in which slurry is received, and a swiveling unit 54 that swirls with a known turntable or an automatic device so that the slurry falling in the slurry storage container can be uniformly stored. It is preferable that the swirl means swirls the slurry storage container with a constant trajectory according to the input program.

  Accordingly, the slurry stored in the slurry storage container is not eccentrically stored in a part, but can be stored in a uniform state in every corner.

  The slurry storage container 52 is preferably formed of a ceramic material having a low thermal conductivity so that the temperature change of the stored slurry can be minimized.

  The semi-solid metal slurry manufactured by the method and apparatus of the present invention as described above was photographed using a known optical microscope as shown in FIGS. 3 to 6, and FIG. Fig. 4 shows the upper part of the tissue, Fig. 4 shows the lower part of the tissue, Fig. 5 shows the inner part of the tissue, and Fig. 6 shows the outer part of the tissue. It can be seen that a uniform spheroidized tissue is formed.

  Therefore, the present invention can not only maintain a constant temperature of the molten metal injected into the melting furnace, but also obtain an overall uniform and fine structure by stirring the electromagnetic field at the liquidus temperature. In addition, the slurry stored in the slurry storage container can be easily manufactured by a single unitized apparatus by providing a condition capable of maintaining a constant temperature without any internal or external temperature deviation. In addition, the entire semi-solid metal slurry can be manufactured to have a uniform spheroidized structure through a simple manufacturing process.

[Industrial applicability]
As described above, the present invention provides a manufacturing method and apparatus capable of manufacturing a semi-solid metal slurry into a uniform spheroidized structure through a simple and simple structure and simple process. A semi-solid metal slurry having a uniform spheroidized structure can have maximum productivity within a short period of time, as well as having the effect of significantly reducing manufacturing costs. .

  Further, by making it possible to minimize the temperature deviation of the molten metal supplied to the melting furnace, there is an effect that it is possible to have an optimum state for producing a semi-solid metal slurry.

  In addition, by allowing a rapid cooling to the molten metal to be performed more efficiently by a cooler in the form of a double tube, the molten metal prevents oxidation in an inert atmosphere so that a dendritic structure is not formed. It also has the effect of making.

  In addition, there is an effect that the slurry stored in the slurry storage container can be uniformly distributed by the swivel means of the storage unit.

It is the schematic block diagram which showed the manufacturing stage of this invention. It is the principal part longitudinal cross-sectional view which showed the manufacturing apparatus of this invention. It is the principal part photograph which showed the structure | tissue state of each part of the semi-solid metal slurry manufactured by this invention. It is the principal part photograph which showed the structure | tissue state of each part of the semi-solid metal slurry manufactured by this invention. It is the principal part photograph which showed the structure | tissue state of each part of the semi-solid metal slurry manufactured by this invention. It is the principal part photograph which showed the structure | tissue state of each part of the semi-solid metal slurry manufactured by this invention. It is the principal part figure which showed the method of manufacturing the conventional semi-solidified metal slurry.

Claims (7)

In an apparatus for producing a semi-solid metal slurry of spheroidized tissue,
A melting furnace 10 formed of a refractory material so that the molten metal is fed into and discharged from the interior of the housing 1 formed at the top;
An electronic stirrer 20 installed such that an electromagnetic field is formed in the melting furnace;
A cooler 30 installed at a lower part of the discharge path of the melting furnace and rapidly cooling the discharged molten metal;
An inclined guide member 40 installed at the lower part of the cooler and guiding the cooled slurry to the lower part;
The storage unit 50 is installed at a lower part of the guide member and uniformly distributes and stores the slurry guided by the guide member.
A space 35 is formed between the inner wall 34 and the outer wall 36 forming the cooler 30, and a passage 32 connected to the discharge path of the melting furnace is formed at the inner center of the inner wall. The semi-solid metal slurry manufacturing apparatus is characterized in that a supply connection pipe 36a connected to the space portion is formed in the inner wall, and a plurality of injection holes 34a connected to the space portion are formed in the inner wall. .   The temperature regulator 60 which adjusts an internal temperature with the inside of the said melting furnace 10 by the atmospheric temperature in a melting furnace and the temperature of a molten metal is comprised, The Claim 1 characterized by the above-mentioned. Semi-solid metal slurry production equipment.   The semi-solid metal slurry according to claim 2, wherein the temperature controller 60 includes a temperature sensor and a heating member that generates heat in response to a signal from the temperature sensor. Manufacturing equipment.   The apparatus for producing a semi-solid metal slurry according to claim 1, wherein the electronic stirrer 20 is installed outside the melting furnace 10 and the cooler 30.   The storage unit 50 includes a slurry storage container 52 in which slurry is received, and swirling means 54 that swirls so that the slurry falling in the slurry storage container can be uniformly stored. An apparatus for producing a semi-solidified metal slurry according to claim 1.   6. The apparatus for producing a semi-solid metal slurry according to claim 5, wherein the turning means turns the slurry storage container with a constant trajectory according to the inputted program.   6. The apparatus for producing a semi-solid metal slurry according to claim 5, wherein the slurry storage container 52 is a ceramic material having a low thermal conductivity.

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