KR20180025260A - Apparatus and Method for Producing Alloy Powder by the Gas and Water Hybrid Process - Google Patents

Abstract

The present invention relates to an apparatus and a method for producing alloy powder by a gas and water injection hybrid process. The apparatus according to the present invention comprises: a crucible into which an alloy raw material is charged and which melts the alloy′s raw material into molten metal; an orifice which is installed at the lower portion of the crucible and discharges the molten metal; a gas spray nozzle which is provided at the lower end of the orifice, and sprays coolant gas to the molten metal to cool the molten metal to be semi-liquid alloy powder; a chamber which is positioned at the lower portion of the gas spray nozzle, receives the semi-liquid alloy powder therein, and disperses and cools the semi-liquid alloy powder to generate alloy powder; an impeller which is installed at the lower end of the inside of the chamber to rotate, and guides the alloy powder generated in the chamber to a recovery container; and a rotation means which applies driving force to rotate the impeller. The molten metal is cooled by the coolant gas and is additionally cooled while passing through the inside of the chamber, thereby generating alloy powder.

Description

TECHNICAL FIELD The present invention relates to an apparatus for producing an alloy powder by a gas and water injection hybrid method and a method for producing the same,

The present invention relates to an apparatus for producing an alloy powder by a gas and water injection hybrid method and a manufacturing method thereof and, more particularly, to an apparatus for manufacturing an alloy powder by a gas and water injection hybrid method, The present invention relates to an apparatus for manufacturing an alloy powder and a method of manufacturing the same.

The atomization process, which is well known as one of methods for producing powders such as pure metals, alloys, ceramics and composites thereof, can be classified into gas spraying method, water dispersion method and mixed spraying method depending on the type of cooling medium.

Since the inert gas (N ₂ , Ar, He) or air is used as the gas spraying method, it is possible to produce a high-quality powder because there is little oxidation and impurity incorporation in the powder production. However, since the cooling effect is low, Segregation occurs and homogeneous alloy powder can not be obtained, and the cost of the used gas is comparatively high, resulting in an increase in production cost.

The water atomization process uses water (H ₂ 0), which is relatively inexpensive instead of gas or air, as the main refrigerant, which is advantageous for producing fine powder because of its small cooling effect due to its small cooling effect. However, it is difficult to apply when the shape and oxidation of the powder to be produced are problematic.

The mixed spraying method is a manufacturing method in which gas (N ₂ , Ar, He), air and water are mixed at a suitable ratio as a cooling medium and is applied as a manufacturing method considering the advantages and disadvantages of the gas spraying method and the water dispersion method described above.

However, when the injection medium (N ² , Ar, He, air and the mixture thereof) is sprayed at a high pressure of 30 kgf / cm ² (about 29.42 bar) or higher to produce an alloy powder by the gas spraying method described above, However, since it is cooled at a relatively low speed while being scattered in the large chamber, it is difficult to prevent micro-segregation of the alloy component, microstructure can not be obtained, and alloy powder production is more difficult.

On the other hand, the water spray method, which has better cooling effect than the gas spray method, can reduce the cost of powder products because it uses relatively inexpensive water and can reduce the micro segregation due to the large cooling effect. However, when the total amount of Fe elements exceeds 85 at% It is known that it is difficult to produce an amorphous alloy powder of 20 μm or more (a cooling rate of 10 ⁵ K / sec or more is required).

In this connection, Korean Patent Laid-Open Publication No. 10-2004-0023534 (published on Mar. 18, 2004), No. 10-2007-0079575 (published Aug. 2007), Laid-open Patent Publication No. 10-2005-0015563 21). The related technologies have been proposed through.

Japanese Laid-Open Patent Application No. 2014-227591 (Apr. 2014, 2014) discloses a method of producing an alloy powder by colliding liquid particles on the surface of a rotating disk and then spraying a cooling medium to recover the alloy powder Have proposed.

As described above, the characteristics of the alloy powder used for various various functions and mechanical parts are determined by the manufacturing method and the process conditions such as the particle size, shape and microstructure of the powder, and the characteristics of the alloy powder are And it is very important in terms of small size and economical aspects of various functional parts.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned conventional problems, and it is an object of the present invention to provide a method for producing a powder of alloy powder, And an object of the present invention is to provide an alloy powder manufacturing apparatus which improves the properties of the alloy powder by increasing the density of the alloy powder (minute density, green density), a manufacturing method using the alloy powder and an alloy powder produced therefrom.

In order to achieve the above object, an apparatus for producing an alloy powder according to the present invention comprises: a crucible for charging an alloy raw material therein and dissolving the alloy raw material in a molten state; An orifice installed at a lower portion of the crucible to discharge the molten metal; A gas injection nozzle provided at a lower end of the orifice and injecting a coolant gas toward the discharged molten metal to cool the molten metal with a half-alloyed alloy powder; A chamber positioned below the gas injection nozzle to receive the semi-liquid phase alloy powder and disperse and cool the semi-liquid phase alloy powder to produce an alloy powder; An impeller rotatably installed at a lower end of the chamber and guiding the alloy powder produced in the chamber to the recovery container; And rotating means for applying a driving force to rotate the impeller, wherein the molten metal is cooled by the refrigerant gas and further cooled while passing through the inside of the chamber to generate alloy powder.

In one specific example, the chamber includes: a rotating cylinder rotatably installed in the chamber, the rotating cylinder being formed in a cylindrical hollow structure and receiving the semi-liquid phase alloy powder therein; A water injection nozzle rotatably installed at an inner center portion of the rotary cylinder and spraying cooling water toward the inner wall of the rotary cylinder; And an auxiliary water injection nozzle installed at the upper end of the rotating cylinder and opened inside to pass the half powdered alloy powder and cooling the rotating cylinder by spraying the refrigerant to the inner wall or the outer wall of the rotating cylinder, The rotating means applies a driving force to the rotating cylinder, the water jetting nozzle and the auxiliary water jetting nozzle, and the rotating direction by the rotating means may be the same as or opposite to the rotating direction of the semi-liquid phase alloy powder falling.

The rotating means may apply a driving force such that the rotation speed per minute of the rotating cylinder rotates at a speed of 2000 rpm or more and 5000 rpm or less. Preferably, the rotation speed per minute may be a speed of 3000 rpm or more and 5000 rpm or less, At this time, the circumferential speed of the rotating cylinder may vary depending on the diameter, but it is preferable that the circumferential speed of the rotating cylinder is more than 30 m / s.

Wherein the water injection nozzle comprises: a cooling water supply part formed in a long hollow structure in the longitudinal direction; And a nozzle unit formed at the upper end of the cooling water supply unit and spraying the cooling water, wherein the nozzle unit is spaced apart from the cooling water supply unit by a predetermined distance, and at least two or more of the nozzle units are formed.

The nozzle unit may have a plurality of through holes formed along the longitudinal direction of the cooling water supply unit or a slit hole structure formed along the longitudinal direction of the cooling water supply unit.

The refrigerant gas may include one or more of argon, nitrogen, air, and water.

Meanwhile, the present invention includes a method for producing an alloy powder by using the apparatus for producing an alloy powder described above,

Charging an alloy raw material into the crucible and dissolving the alloy raw material in a molten state; Discharging the molten metal from the orifice; A step of spraying a refrigerant gas toward the molten metal while the molten metal is being dropped and cooling and spraying the molten metal with a half-phase alloy powder; Transferring the half-phase alloy powder into the chamber, dispersing and cooling the alloy powder to produce an alloy powder; And guiding the alloy powder to the collection container using the impeller.

The step of producing the alloy powder may include a step of cooling the inner wall or the outer wall of the rotary cylinder by the auxiliary water injection nozzle; A step of secondarily cooling the semi-liquid phase alloy powder to the inside of the rotating cylinder and coming into contact with the inner wall of the rotating cylinder; And a step of third cooling the semi-liquid phase alloy powder by bringing it into contact with cooling water sprayed from a water spray nozzle.

At this time, since the cooling water is injected from the water spray nozzle while rotating at a high pressure of 100 bar or more, the half-liquid phase alloy powder can be effectively cooled by contacting with the cooling water.

According to the apparatus and method for producing an alloy powder according to the present invention, the alloy raw material is first cooled with a half-phase alloy powder by a gas injection nozzle, and further cooled by a rotating cylinder and a water jetting nozzle to produce alloy powder, It is possible to produce a spherical alloy powder having a small amount of fine segregation and satellite powder, and the effect of improving the properties of the alloy powder by increasing the molding density is provided.

1 is a cross-sectional view of an apparatus for producing an alloy powder according to an embodiment of the present invention.
2 is a cross-sectional view taken along line A-A 'in Fig.
3 is a cross-sectional view taken along the line B-B 'in Fig.
4 is a cross-sectional view taken along the line C-C 'in Fig.
Fig. 5 is a sectional view of the water jet nozzle of Fig. 1;
6 is a photograph showing the shapes of the alloy powder prepared by the present invention and the alloy powder prepared by the conventional gas atomization method, respectively.

While the invention is susceptible to various modifications and alternative forms, specific embodiments thereof are shown by way of example in the drawings and will herein be described in detail. It is to be understood, however, that the invention is not to be limited to the specific embodiments, but is to be understood to include all modifications, equivalents, and alternatives falling within the spirit and scope of the invention, And the scope of the present invention is not limited to the following examples.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings, so that those skilled in the art can easily carry out the present invention.

1 is a cross-sectional view of an apparatus for producing an alloy powder according to an embodiment of the present invention.

1, an apparatus 500 for producing an alloy powder according to an embodiment of the present invention includes a melting chamber 100, a gas injection nozzle 200, a chamber 300, and a rotating means 400, .

A melting chamber 100 capable of dissolving an alloy material in a solid state in a suitable atmosphere is disposed on the upper part of the alloy powder manufacturing apparatus 500. The melting chamber 100 is composed of a crucible 110, And may include an induction coil 120.

The crucible 110 is installed inside the melting chamber 100 and a cylindrical orifice 111 is provided below the crucible 110. A stopper 112 is provided on the upper side of the orifice 111, May be provided.

First, the crucible 110 is charged with a solid alloy material in its inside and dissolves the alloy material in the melt 2. A high frequency induction furnace in which the high frequency induction coil 120 is wound is installed on the outer surface of the crucible 110 to dissolve the alloy raw material charged in the crucible 110 into the molten liquid 2.

The molten metal 2 is discharged downward through the orifice 111 and the stopper 112 can block the discharge of the molten metal 2 by controlling the opening and closing of the orifice 111.

Meanwhile, the dissolution chamber 100 may include a gas circulation valve 101 for controlling the flow of gas and appropriately controlling the internal atmosphere, and a pressure gauge (not shown) for checking the gas pressure.

The gas injection nozzle 200 may be positioned below the dissolution chamber 100.

The gas injection nozzle 200 may be installed at a lower or lower side of the orifice 111 in a ring shape. Under the above-described structure, the gas injection nozzle 200 discharges the refrigerant gas (Ar, N ₂ , He, air, water, and the like) at a high pressure in the range of 10 bar to 1000 bar toward the molten metal 2 discharged from the orifice 111 The mixture thereof) is sprayed and subjected to primary cooling to produce an alloy powder 3 in a half-liquid phase.

Since the gas injection nozzle 200 injects the refrigerant gas 201 so as to intersect at an intersection 50 formed at the lower side, the half-liquid phase alloy powder 3 is injected into the chamber 300 located at the lower side It is delivered in scattered form.

Although only the configuration of the gas injection nozzle 200 is shown in the lower part of the dissolution chamber 100 in the figure, the configuration in which the gas injection nozzle 200 is located inside the dissolution chamber 100 is also described in the present invention Of the present invention.

The chamber 300 is positioned below the gas injection nozzle 200 to receive the semi-liquid phase alloy powder 3 and disperse and cool the same to produce an alloy powder 4, An auxiliary water injection nozzle 320, a water injection nozzle 330, and an impeller 340. The auxiliary water injection nozzle 320,

The rotation cylinder 310 is rotatably installed in the chamber 300 and can rotate at a high speed within the chamber 300 with the water injection nozzle 330 as a reference axis. The rotary cylinder 310 may have a cylindrical hollow structure in which the upper and lower portions are opened and the vertical cross-sectional area is widened toward the lower portion.

Accordingly, the half-liquid alloy powder 3 generated by the high-pressure refrigerant gas 201 injected from the gas injection nozzle 200 falls into a scattered form and is transferred to the interior of the rotary cylinder 310.

Next, the auxiliary water injection nozzle 330 may be installed on the rotation cylinder 310.

The auxiliary water molecule nozzle 320 may be formed to open inside and allow the semi-liquid phase alloy powder 3 to be passed through the rotating cylinder 310 to pass therethrough. The auxiliary water injection nozzle 330 injects the refrigerant 320a toward the inner wall of the rotary cylinder 310 through a nozzle hole 321 formed on one surface of the rotary cylinder 310 facing the rotary cylinder 310, The inner wall surface 311 of the heat sink 310 can be cooled to a low temperature state.

Next, the water injection nozzle 330 may be rotatably installed inside the rotation cylinder 310. [

The water injection nozzle 330 is rotatably installed at the inner center portion of the lower end of the rotation cylinder 310 and can spray the cooling water 330a toward the inner wall of the rotation cylinder 310 while rotating at a high speed, A cooling water supply unit 331 for supplying the cooling water 330a and a nozzle unit 332 for spraying the cooling water 330a.

The cooling water supply unit 331 may be installed in a structure communicating with the outside of the chamber 300 at the center of the inner lower end of the rotary cylinder 310. The cooling water supply unit 331 may have an internal hollow structure to supply the cooling water 330a. The upper end of the cooling water supply unit 331 may have a conical shape extending in the longitudinal direction, and the lower end may have a pipe structure communicating with the exterior.

The nozzle unit 332 may be formed on the outer surface of the upper end of the cooling water supply unit 331 to spray the cooling water 330a. Referring to FIG. 3, a sectional view taken along the line B-B ' 5 is a side cross-sectional view of the upper end structure of the water injection nozzle.

1 and 5, the nozzle unit 332 includes a slit hole 332a formed along the longitudinal direction of the cooling water supply unit 331, or a plurality of through holes 332b formed along the longitudinal direction ) Structure.

The higher the water pressure of the cooling water 330a sprayed from the nozzle parts 332a and 332b is, the higher the speed at which the semi-liquid alloy powder 3 is cooled. Therefore, the structure of the slit hole 332a of the nozzle part 332 The structure of the through hole 332b is preferably designed to withstand a water pressure of 50 bar or more.

Referring to FIGS. 1 and 3, the vertical cross-sectional area of the water injection nozzle 330 is divided into four along the outer periphery of the cooling water supply unit 331, 332 are formed at an equal angle with each other at an angle of 90 degrees.

3, the water injection nozzle 330 is configured such that the cooling water supply unit 331 rotates at a high speed and the cooling water 330a is supplied to the inner wall 311 of the rotary cylinder 310 through the nozzle unit 332 A water flow layer rotating in a counterclockwise direction (Fig. 3 (a)) or a clockwise direction (Fig. 3 (b)) is formed between the water injection nozzle 330 and the inner wall 311 of the rotary cylinder 310 . The above-mentioned semi-liquid phase alloy powder 3 is passed through this water flow layer and cooled.

In this cooling process, a part of the semi-liquid phase alloy powder 3 bumps against the inner wall 311 of the rotary cylinder 310, and the inner wall 311 of the rotary cylinder 310 contacts the auxiliary water injection nozzle 320, The cooling can be performed in the process of the half-liquid phase alloy powder 3 hitting against the inner wall 311. In this case,

Next, the impeller 340 may be rotatably installed in an inner lower portion of the chamber 300.

The impeller 340 is integrally rotatable by being bolted to an edge portion 315 extending from the lower end of the rotary cylinder 310 at an inner lower portion of the chamber 300, The rotation force generated while rotating can guide the alloy powder 4 generated through the cooling process in the rotation cylinder 310 to the recovery container 301.

In this regard, FIG. 4 is a cross-sectional view taken along line C-C 'of FIG.

4 is a sectional view of the impeller 340. The number and size of the blades 341 of the impeller 340 depend on the amount of the refrigerant gas 201 injected from the gas injection nozzle 200, The spray amount of the cooling water 330a injected from the injection nozzle 330 and the rotation speed (rpm) of the impeller 340. [

The rotation cylinder 310, the water injection nozzle 330 and the impeller 340 receive the driving force from the rotation means 400 provided on the outside of the chamber 300 and rotate the water injection nozzle 330 It can be rotated by an axis.

The rotating means 400 includes a driving shaft 401, a hollow driving shaft 402 and a driving shaft housing 403 for rotating the rotating cylinder 310, the impeller 340 and the water jetting nozzle 330 And a pulley 404, a belt 405, and a driving motor 410 for rotating the hollow driving shaft 402 at a high speed.

The rotating means 400 can apply a driving force to rotate the rotating cylinder 310 and the water jetting nozzle 330 at a speed of 3000 rpm or more. At this time, the circumferential speed of the rotating cylinder varies depending on the diameter However, it is preferable that the circumferential speed is rotated at 30 m / s or more.

2 is a cross-sectional view taken along line A-A 'in FIG. 1, in which the molten metal 2 discharged from the orifice 111 is scattered by the high-pressure refrigerant gas 201 injected from the gas injection nozzle 200 FIG. 2 (a) shows a state in which the half-liquid phase metal powder 3 rotates in a counterclockwise direction, and FIG. 2 (b) shows a state in which the metal powder 3 rotates in a clockwise direction. .

In this regard, the rotating means 400 may improve the cooling efficiency by rotating the rotating cylinder 310 and the water spraying nozzle 330 in the direction opposite to the rotating direction of the half-liquid phase metal powder 3 have.

For example, when the semi-liquid phase metal powder 3 rotates counterclockwise as shown in FIG. 2 (a), the rotation means 400 rotates the rotation cylinder 310 and the water injection nozzle 330, (See Fig. 3 (b)), it is possible to increase the number and area of contact of the half-liquid phase metal powder 3 with the water layer formed by the cooling water 330a, thereby improving the cooling efficiency. Likewise, when the half-liquid phase metal powder 3 rotates clockwise as it falls, the rotation means 400 rotates the rotation cylinder 310 and the water injection nozzle 330 counterclockwise in the opposite direction The cooling efficiency can be improved.

FIG. 6 is a photograph showing the shapes of the alloy powders produced by the present invention and the alloy powders produced by the conventional gas spraying method, respectively.

Fig. 6 (a) is a photograph of an alloy powder produced by the present invention, and Fig. 6 (b) is a photograph of an alloy powder produced by a conventional gas atomization method.

The alloy powder according to the present invention has an inner diameter of 2.5 mm, an injection pressure of the refrigerant gas of 30 kgf / cm < ² >, an inner diameter of the rotating cylinder The circumferential speed of the water spray nozzle was set to 25 m / sec, and the pressure of the cooling water sprayed from the water spray nozzle was set to 50 bar, 60 Liter / min.

6 (a) and 6 (b), it can be seen that the alloy powder produced by the present invention is spherical alloy powder having less satellite powder than the conventional alloy powder. That is, since the alloy powder is produced by the hybrid method of the gas and the water yarn by the coolant gas and the cooling water, the present invention can obtain the spherical alloy powder having less fine segregation.

The particle size and shape of the alloy powder can be differently adjusted by adjusting the process conditions such as the temperature of the molten metal, the inner diameter of the orifice, and the injection pressure of the refrigerant gas.

While the present invention has been described in connection with what is presently considered to be practical exemplary embodiments, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, And such variations and modifications are intended to fall within the scope of the appended claims.

2: melt
3: Half-liquid phase alloy powder
4: Alloy powder
100: melting chamber
110: Crucible
111: Orifice
112: Stopper
120: high frequency induction coil
200: gas injection nozzle
300: chamber
310: rotating cylinder
320: auxiliary water jet nozzle
330: Water injection nozzle
340: impeller
400: rotating means
500: Alloy powder manufacturing equipment

Claims (8)

A crucible for charging an alloy raw material therein and dissolving the alloy raw material in a molten state;
An orifice installed at a lower portion of the crucible to discharge the molten metal;
A gas injection nozzle provided at a lower end of the orifice and injecting a coolant gas toward the discharged molten metal to cool the molten metal with a half-alloyed alloy powder;
A chamber positioned below the gas injection nozzle to receive the semi-liquid phase alloy powder and disperse and cool the semi-liquid phase alloy powder to produce an alloy powder;
An impeller rotatably installed at a lower end of the chamber and guiding the alloy powder produced in the chamber to the recovery container; And
And rotating means for applying a driving force to rotate the impeller,
Wherein the molten metal is cooled by the refrigerant gas and is further cooled while passing through the inside of the chamber to produce an alloy powder. The apparatus of claim 1,
A rotating cylinder rotatably installed in the chamber and formed in a cylindrical hollow structure to receive the semi-liquid phase alloy powder therein;
A water injection nozzle rotatably installed at an inner center portion of the rotary cylinder and spraying cooling water toward the inner wall of the rotary cylinder; And
And an auxiliary water injection nozzle installed at an upper end of the rotary cylinder to open inside to pass the semi-liquid phase alloy powder and to cool the rotary cylinder by spraying the refrigerant to the inner wall or the outer wall of the rotary cylinder,
Wherein the rotating means applies driving force to the rotating cylinder, the water jetting nozzle and the auxiliary water jetting nozzle, and the rotating direction by the rotating means is the same as or opposite to the rotating direction of the semi-liquid phase alloy powder falling Wherein the alloy powder is a powder. 3. The apparatus according to claim 2,
Wherein the driving force is applied so that the number of revolutions per minute of the rotating cylinder rotates at a speed of 2000 rpm or more and 5000 rpm or less. The water jetting apparatus according to claim 2,
A cooling water supply part formed in a longitudinally long hollow structure; And
And a nozzle unit formed at an upper end of the cooling water supply unit to spray cooling water,
Wherein the nozzle unit is spaced apart from each other by a predetermined distance along the circumference of the cooling water supply unit, and at least two of the nozzle units are formed. The ink jet recording head according to claim 4,
Wherein the cooling water supply unit has a plurality of through holes formed along the longitudinal direction of the cooling water supply unit or a slit hole structure formed along the longitudinal direction of the cooling water supply unit. The apparatus for producing an alloy powder according to claim 1, wherein the refrigerant gas comprises at least one of argon, nitrogen, air, and water. A method for producing an alloy powder using the apparatus for producing an alloy powder according to claim 1,
Charging an alloy raw material into the crucible and dissolving the alloy raw material in a molten state;
Discharging the molten metal from the orifice;
A step of spraying a refrigerant gas toward the molten metal while the molten metal is being dropped and cooling and spraying the molten metal with a half-phase alloy powder;
Transferring the half-phase alloy powder into the chamber, dispersing and cooling the alloy powder to produce an alloy powder; And
And guiding the alloy powder to the recovery container using the impeller. 8. The method of producing an alloy powder according to claim 7,
A step of cooling the inner wall or outer wall of the rotary cylinder by the auxiliary water injection nozzle;
A step of secondarily cooling the semi-liquid phase alloy powder to the inside of the rotating cylinder and coming into contact with the inner wall of the rotating cylinder; And
And a third cooling step of bringing the semi-liquid phase alloy powder into contact with cooling water sprayed from a water spray nozzle.

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