JP6330958B1 - Metal powder manufacturing apparatus and metal powder manufacturing method - Google Patents

Abstract

An apparatus for producing a metal powder that exhibits an excellent cooling action is provided. A molten metal supply unit that discharges molten metal, a cylindrical body that is installed below the molten metal supply unit, and a flow of a cooling liquid that cools the molten metal discharged from the molten metal supply unit. A cooling liquid flow forming unit formed in the cylindrical body, wherein the cooling liquid flow forming unit spreads in a film shape from the upper part to the lower part in the axial direction of the cylindrical body. A metal powder manufacturing apparatus, characterized in that a coolant flows out along an inner peripheral wall of the cylindrical body to form a flow of the cooling liquid in the cylindrical body. [Selection] Figure 2

Description

  The present invention relates to a metal powder production apparatus and a metal powder production method.

  For example, as shown in Patent Document 1, a metal powder manufacturing apparatus that manufactures metal powder using a so-called gas atomization method and a manufacturing method using the apparatus are known. The conventional apparatus includes a molten metal supply container that discharges molten metal, a cylinder installed below the molten metal supply container, and a flow of a coolant that cools the molten metal discharged from the molten metal supply unit. And a cooling liquid layer forming part formed along the inner peripheral wall of the cylindrical body.

  The cooling liquid layer forming means sprays the cooling liquid linearly toward the tangential direction of the inner peripheral wall of the cooling cylinder, and causes the cooling liquid to flow down while swirling along the inner peripheral wall of the cooling container. Forming a layer. By using the cooling liquid layer, it is expected that the droplets can be rapidly cooled to produce a highly functional metal powder.

  However, in the conventional apparatus, even if the cooling liquid is sprayed linearly toward the tangential direction of the inner peripheral wall of the cooling cylinder, a part of the cooling liquid collides with the inner peripheral wall of the cylindrical body and bounces off. This causes a problem of entraining a large amount of air in the liquid flow and cannot provide a sufficient cooling effect.

Japanese Patent Laid-Open No. 11-80812

  This invention is made | formed in view of such an actual condition, The objective is to provide the manufacturing method of the metal powder which uses the metal powder manufacturing apparatus which has the outstanding cooling effect | action, and it.

In order to achieve the above object, a metal powder production apparatus according to the present invention comprises:
A molten metal supply unit for discharging the molten metal;
A cylinder installed below the molten metal supply unit, and a cooling liquid flow forming unit that forms a flow of cooling liquid for cooling the molten metal discharged from the molten metal supply unit in the cylinder. A metal powder production apparatus comprising:
The cooling liquid flow forming part flows out the cooling liquid spreading in a film shape from the upper part to the lower part in the axial direction of the cylindrical body along the inner peripheral wall of the cylindrical body, and flows the cooling liquid into the cylindrical body. It is characterized by forming.

In order to achieve the above object, a method for producing a metal powder according to the present invention comprises:
Forming a flow of the coolant along the inner peripheral wall of the cylinder installed below the molten metal supply unit;
Discharging the molten metal from the molten metal supply unit toward the flow of the cooling liquid, and a method for producing a metal powder comprising:
In the step of forming the flow of the cooling liquid, the cooling liquid that spreads in a film shape downward from the upper part of the cylindrical body flows out along the inner peripheral wall of the cylindrical body.

  In the metal powder production apparatus and the metal powder production method according to the present invention, the coolant that spreads in a film shape from the upper part to the lower part in the axial direction of the cylinder flows out along the inner peripheral wall of the cylinder, and enters the cylinder. Forming a flow of the cooling liquid; In the conventional metal powder manufacturing apparatus, since the cooling liquid was caused to flow out linearly, there was a problem of entraining a large amount of air in the flow of the cooling liquid. In the present invention, the cooling liquid is spread in a film shape. By flowing out from above the cylinder as much as possible, it is possible to effectively suppress the problem of involving atmospheric gas such as air in the flow of the cooling liquid, and to enhance the cooling effect by the cooling liquid.

  Further, for example, the coolant flow forming portion has a first flow path cross-sectional area, and an inflow portion that allows the coolant to flow into the interior, and from the inflow portion toward the lower portion in the axial direction, An expanded flow path portion in which the flow path cross-sectional area gradually increases to a second flow path cross-sectional area wider than the first flow path cross-sectional area, and a third flow path cross-sectional area narrower than the second flow path cross-sectional area And a cooling liquid discharge section for discharging the cooling liquid in a film shape along the inner peripheral wall.

  In the metal powder manufacturing apparatus having such a cooling flow forming portion, the cooling liquid passes through the enlarged flow path portion, thereby generating a flow in which the cooling flow spreads downward. A cooling liquid spreading in a film shape toward the surface can be suitably formed. In addition, since the third channel cross-sectional area, which is the channel cross-sectional area of the coolant discharge part, is narrower than the second channel cross-sectional area in the enlarged channel part, the flow rate of the coolant flowing out is increased and melted. The metal cooling efficiency can be increased.

  In addition, for example, the coolant discharge section may extend along a concentric direction of the inner peripheral wall of the cylindrical body. Since the cooling liquid discharge portion extends in the concentric direction of the inner peripheral wall, the flow of the cooling liquid is preferably formed along the inner peripheral wall, so that the problem of air being caught in the flow of the cooling liquid can be prevented. .

  Further, for example, the metal powder manufacturing apparatus has a plurality of the cooling liquid flow forming portions, and the plurality of cooling liquid flow forming portions are along a plane orthogonal to the axial direction of the cylindrical body, and You may arrange | position along the concentric direction of the said internal peripheral wall in the said cylinder. The number of cooling liquid forming parts included in the metal powder manufacturing apparatus is not particularly limited, but the flow of the cooling liquid is suitably formed along the inner peripheral wall by arranging the plurality of cooling liquid forming parts in the concentric direction. Therefore, it is possible to prevent the problem that air is involved in the flow of the coolant.

FIG. 1 is a schematic cross-sectional view of a metal powder manufacturing apparatus according to an embodiment of the present invention. FIG. 2 is a perspective view showing a coolant flow forming unit and a coolant supply unit included in the metal powder apparatus shown in FIG.

  Hereinafter, the present invention will be described based on embodiments shown in the drawings.

First Embodiment As shown in FIG. 1, a metal powder manufacturing apparatus 10 according to an embodiment of the present invention is formed of a large number of metal particles by cooling and solidifying a molten metal 21 by an atomizing method (gas atomizing method). An apparatus for obtaining metal powder. The metal powder manufacturing apparatus 10 includes a molten metal supply unit 20 that discharges the molten metal 21 and a cooling unit 30 that is disposed below the molten metal supply unit 20 in the vertical direction. In the drawings, the vertical direction is a direction along the Z axis.

  The molten metal supply unit 20 includes a heat-resistant container 22 that stores the molten metal 21. A heating coil 24 is disposed on the outer periphery of the heat resistant container 22, and the molten metal 21 accommodated in the heat resistant container 22 is heated and maintained in a molten state. A discharge port 23 is formed at the bottom of the heat-resistant container 22, from which the molten metal 21 is directed toward the coolant flow 60 formed on the inner peripheral wall 33 of the cylindrical body 32 of the cooling unit 30. It is discharged as dripping molten metal 21a.

  A gas injection unit 26 is disposed on the outer peripheral portion of the outer bottom wall of the heat resistant container 22 so as to surround the discharge port 23. The gas injection unit 26 includes a gas injection port 27. High-pressure gas is injected from the gas injection port 27 toward the dropped molten metal 21 a discharged from the discharge port 23. The high-pressure gas is jetted obliquely downward from the entire circumference of the dropped molten metal 21a discharged from the discharge port 23. The dropped molten metal 21a becomes a large number of droplets, and is cylindrical along the gas flow. It is carried toward the flow 60 of the coolant formed on the inner peripheral wall 33 in the portion 32a.

  The molten metal 21 may contain any element. For example, a metal containing at least one of Ti, Fe, Si, B, Cr, P, Cu, Nb, and Zr can be used. These elements are highly active, and the molten metal 21 containing these elements is easily oxidized to form an oxide film by contact with air for a short period of time, making it difficult to miniaturize. Yes. As described above, the metal powder manufacturing apparatus 10 uses an inert gas as a gas to be injected from the gas injection port 27 of the gas injection unit 26, thereby preventing the progress of oxidation even if the molten metal 21 is easily oxidized. It can be pulverized.

  The gas injected from the gas injection port 27 is preferably an inert gas such as nitrogen gas, argon gas or helium gas, or a reducing gas such as ammonia decomposition gas. However, if the molten metal 21 is a metal that is difficult to oxidize. Air may be used.

  The cooling unit 30 includes a cylindrical body 32 installed below the molten metal supply unit 20, a cooling liquid flow forming unit 40 that forms a coolant flow 60 for cooling the molten metal 21 in the cylindrical body 32, and a cooling liquid And a supply unit 50 (see FIG. 2 for the coolant supply unit 50). The cylindrical body 32 has a cylindrical portion 32a connected to one end of the cylindrical portion 32a connected to the molten metal supply portion 20 and a conical portion 32b connected to the other end of the cylindrical portion 32a. Have The inner diameter of the inner peripheral wall 33 of the cylindrical portion 32a is not particularly limited, but is preferably 50 to 500 mm.

  In the present embodiment, the axial direction O of the cylindrical body 32 is inclined at a predetermined angle θ1 with respect to the vertical line Z. Although it does not specifically limit as predetermined angle (theta) 1, Preferably, it is 5-45 degree | times. By setting it as such an angle range, it becomes easy to discharge the dripping molten metal 21a from the discharge outlet 23 toward the flow 60 of the coolant formed in the inner peripheral wall 33 of the cylindrical body 32. The arrow in the axial direction O is a direction from the upper part to the lower part of the cylindrical body 32.

  The dropped molten metal 21a discharged toward the coolant flow 60 in the cylindrical body 32 collides with the coolant flow 60, and is rapidly cooled and solidified to become a solid metal powder. A discharge portion 34 is provided below the cylindrical body 32 along the axial direction O, and the metal powder contained in the coolant flow 60 can be discharged together with the coolant to the outside. The metal powder discharged together with the cooling liquid is separated from the cooling liquid and taken out in an external storage tank or the like. The cooling liquid is not particularly limited, but cooling water is used.

  An adjustment plate 35 is fixed to the inner peripheral wall 33 on the downstream side of the coolant flow 60.

  In the present embodiment, the coolant flow forming portion 40 is provided in the upper part of the cylindrical body 32 in the axial direction O. The cooling liquid flow forming part 40 flows out the cooling liquid that spreads in a film shape from the upper part to the lower part in the axial direction O of the cylindrical body 32 along the inner peripheral wall 33 of the cylindrical body 32 via the cooling liquid discharge part 46. Then, a coolant flow 60 is formed in the cylinder 32.

  The coolant flow forming unit 40 shown in FIG. 1 flows out the coolant so as to spread in a film shape along the inner peripheral wall 33 of the cylindrical body 32. FIG. 2 is a perspective view showing the coolant flow forming part 40 and the coolant supply part 50 (not shown in FIG. 1) shown in FIG. As shown in FIG. 2, the coolant flow forming portion 40 is arranged in a ring shape along a plane P orthogonal to the axial direction O of the cylindrical body 32 and along the concentric direction V of the inner peripheral wall 33 of the cylindrical body 32. The first coolant flow forming unit 40A, the second coolant flow forming unit 40B, the third coolant flow forming unit 40C, and the fourth coolant flow forming unit 40D are configured. The first to fourth cooling liquid flow forming portions 40A to 40D have the same shape and structure except that the arrangement with respect to the concentric direction V is different. Therefore, the first cooling liquid flow forming portion 40A will be described as an example. The description of the other coolant flow forming unit is omitted.

  As shown in FIG. 2, the first coolant flow forming part 40 </ b> A has an inflow part 42, an enlarged flow path part 44, and a coolant discharge part 46. The inflow portion 42 is located at the upper end of the first coolant flow forming portion 40A, and allows the coolant to flow into the first coolant flow forming portion 40A. The inflow part 42 is connected to a first coolant supply part 50 </ b> A that supplies the coolant to the inflow part 42.

  The inflow part 42 and the first coolant supply part 50A have a first flow path cross-sectional area S1. As will be described later, at least a part of the enlarged flow path portion 44 constituting the inside of the first coolant flow forming section 40A, preferably the entire enlarged flow path portion 44, has a flow wider than the first flow path cross-sectional area S1. It has a road cross-sectional area.

  As shown in FIG. 2, an enlarged flow path portion 44 is connected below the inflow portion 42. The enlarged flow path portion 44 gradually expands from the inflow portion 42 downward in the axial direction O to a second flow path cross-sectional area S2 wider than the first flow path cross-sectional area S1. It is configured. As shown in FIG. 2, the channel width of the enlarged channel portion 44 is wider in both the radial direction N of the cylindrical body 32 and the concentric direction V of the inner peripheral wall 33 than the inflow portion 42.

  The flow passage width of the enlarged flow passage portion 44 gradually expands in the concentric direction V of the inner peripheral wall 33 toward the lower side in the axial direction O of the cylindrical body 32, so that the coolant flow 60 flows in the cylindrical body 32. A coolant layer can be formed so as to suitably cover the inner peripheral wall 33. In addition, since the enlarged flow path portion 44 has a larger flow path cross-sectional area than the inflow portion 42 and the coolant discharge portion 46, the flow direction of the coolant is appropriately adjusted while suppressing the occurrence of turbulent flow. can do. As shown in FIG. 2, the enlarged flow path portion 44 only needs to have a portion where the flow path cross-sectional area expands downward in the axial direction O, and in addition, the flow path cross-sectional area is constant. You may have the other part which is.

  As shown in FIG. 2, the coolant discharge part 46 is formed on the flow path bottom wall 44 b of the enlarged flow path part 44 in the first coolant flow forming part 40 </ b> A and flows through the enlarged flow path part 44. The coolant that has flown out is allowed to flow out in the form of a film along the inner peripheral wall 33 of the cylinder 32 that continues downward. The coolant discharge part extends along the concentric direction V of the inner peripheral wall 33, and the flow path width in the concentric direction V is longer than the radial flow path width.

  The coolant discharge part 46 has a third flow path cross-sectional area S3 that is narrower than the second flow path cross-sectional area S2, and extends from the first coolant flow forming part 40A along the inner peripheral wall 33 of the cylindrical body 32. Then, the cooling liquid is allowed to flow out into a film. Since the coolant discharge part 46 has an elongated gap shape extending along the concentric direction V of the inner peripheral wall 33, unlike the circular coolant discharge part, the coolant can flow out in a film shape.

  The coolant discharge section 46 has a third flow path cross-sectional area S3 that is narrower than the second flow path cross-sectional area S2 in the upper enlarged flow path section 44. Therefore, the flow 60 of the coolant formed on the inner peripheral wall 33 is provided. The metal powder manufacturing apparatus 10 having such a coolant discharge section 46 can effectively cool the dropped molten metal 21a.

  As shown in FIG. 2, the second to fourth coolant flow forming portions 40B to 40D are also similar to the first coolant flow forming portion 40A, the inflow portion 42, the enlarged flow path portion 44, and the coolant discharge. Part 46. The second to fourth coolant supply units 50B to 50D are connected to the coolant discharge parts 46 of the second to fourth coolant flow forming parts 40B to 40D, respectively.

  As shown in FIG. 2, in the coolant flow formation unit 40, a plurality of coolant discharge units 46 are arranged along the orthogonal plane P <b> 1 and the concentric direction V. With such an arrangement, it is possible to more suitably prevent the problem that air or the like is involved in the coolant flow 60 formed on the inner peripheral wall 33 of the cylindrical body 32. The numbers of the inflow part 42, the enlarged flow path part 44, and the cooling liquid discharge part 46 included in the cooling liquid flow forming part 40 are not particularly limited, and may be singular or plural. It is preferable to do. Note that the number of the coolant discharge portions 46 and the enlarged flow passage portions 44 may be the same or different. For example, the enlargement flow passage portions 44 and the coolant discharge portions 46 are continuous along the concentric direction V. You may do it.

  As shown in FIG. 1, the radial position of the outer diameter end of the coolant discharge part 46 included in each of the first to fourth coolant flow forming parts 40A to 40D is the diameter of the inner peripheral wall 33 in the cylindrical part 32a. It is preferable to match the directional position from the viewpoint of preventing air or the like from being entrained in the coolant flow 60.

  The coolant that has flowed out of the coolant flow forming unit 40 as shown in FIG. 2 is formed in the cylindrical body 32 by the direction of the flow formed by the coolant flow forming unit 40 and the gravity that acts on the coolant after flowing out. A coolant flow 60 is formed along the peripheral wall 33. In the metal powder manufacturing apparatus 10 shown in FIG. 1, the dropped molten metal 21 a shown in FIG. 1 is incident on the inner peripheral liquid surface of the coolant flow 60 formed in this way, and the dropped molten metal 21 a is cooled. While being cooled inside the liquid flow 60, it flows with the cooling liquid and moves toward the discharge portion 34.

  In the metal powder manufacturing apparatus 10 according to the present embodiment, the coolant flow forming unit 40 causes the coolant to flow out so as to spread downward in a film shape, and thus the coolant flow 60 along the inner peripheral wall 33 of the cylindrical body 32. However, it is difficult to entrain air or the like, and it is possible to efficiently cool the dropped molten metal 21a incident on the coolant flow 60. Further, in such a metal powder manufacturing apparatus 10, even if the pressure of the coolant supplied to the coolant flow forming unit 40 is increased, a turbulent flow such that the coolant flow 60 entrains air or the like is generated. Therefore, it is possible to rapidly cool the dripped molten metal 21a using the coolant flow 60 that is high-speed and laminar.

  As mentioned above, although embodiment was shown and the metal powder manufacturing apparatus which concerns on this invention was demonstrated, this invention is not limited only to the metal powder manufacturing apparatus 10 mentioned above, and having other embodiment and a modified example Needless to say. For example, the first to fourth cooling liquid flow forming parts 40A to 40D shown in FIG. 2 are connected to the first to fourth cooling liquid supply parts 50A to 50D extending along the axial direction O. The liquid supply unit may be connected to the cooling liquid flow forming unit from a direction inclined with respect to the axial direction O. As a result, the coolant flowing out from the coolant discharge section 46 can also be inclined with respect to the axial direction O, and the coolant flow 60 can be made into a spiral swirl flow.

  Hereinafter, although this invention is demonstrated based on a more detailed Example, this invention is not limited to these Examples.

EXAMPLE Using the metal powder production apparatus 10 shown in FIG. 1, Fe-Si-B (Experiment No. 6), Fe-Si-Nb-B-Cu (Experiment No. 7), Fe-Si-B-P-Cu (Experiment No. 8), Fe-Nb-B (Experiment No. 9), and Fe-Zr-B (Experiment No. 10) were produced.

  In each experiment, the dissolution temperature was 1500 ° C., the injection gas pressure was 5 MPa, the gas type argon used was constant, and the coolant flow condition was a pump pressure of 7.5 kPa. In the examples, metal powder having an average particle diameter of about 25 μm could be produced. The average particle size was determined by measurement using a dry particle size distribution measuring device (HELLOS). Moreover, the crystal analysis of the metal powder produced by experiment number 6-10 was evaluated by the powder X-ray diffraction method. The magnetic properties of the metal powder were measured by measuring the coercive force (Oe) with an Hc meter. The results are shown in Table 1.

Comparative Example A metal powder (experiment number) was prepared in the same manner as in the example using the same metal powder production apparatus as in the example, except that a circular coolant discharge unit was provided and the coolant flowed out linearly. 1-5) were produced and evaluated similarly. The results are shown in Table 1.

  Comparing the examples of Table 1 and the comparative example, the magnetic properties were improved and the amorphousness was improved. This is because the flow of the coolant is further rectified by passing through the coolant discharge portion 46, so that the flow of the coolant becomes uniform, a more effective cooling effect is obtained, and there is less powder that is insufficiently cooled. it is conceivable that. Further, when the crystal analysis of the metal powder was performed by powder X-ray diffraction, there was a comparative example having a peak due to the crystal. When compared with the same composition, for the magnetic properties of the metal powder, the comparative example has a larger coercive force than the example, it can be confirmed that the magnetic properties accompanying the amorphization in the example appears significantly, It was confirmed that an excellent cooling effect was obtained in the examples.

  Comparing the above comparative example with the example, the flow of the cooling liquid is rectified without being turbulent even when the pump pressure is high, by using the cooling liquid flow forming section that causes the cooling liquid to flow out in a film shape. As a result, the cooling effect of the metal powder increased, amorphousness could be confirmed even for compositions that could not be produced conventionally, and magnetic properties could be improved.

DESCRIPTION OF SYMBOLS 10 ... Metal powder manufacturing apparatus 20 ... Molten metal supply part 21 ... Molten metal 21a ... Dripping molten metal 22 ... Heat-resistant container 23 ... Discharge port 24 ... Heating coil 26 ... Gas injection part 27 ... Gas injection part 30 ... Cooling part 32 ... cylindrical body 32a ... cylindrical part 32b ... conical part 33 ... inner peripheral wall 34 ... discharge part 35 ... adjusting plate 40 ... cooling liquid flow forming part 40A-40D ... first to fourth cooling liquid flow forming part 42 ... inflow part 44 ... Enlarged flow path 44b ... Flow path bottom wall 46 ... Coolant discharge part 50 ... Coolant supply part 50A-50D ... 1st-4th coolant supply part 60 ... Coolant flow S1-S3 ... 1st ~ Third channel cross-sectional area N ... radial direction OO ... axial direction P1 ... orthogonal plane V ... concentric direction

Claims (4)

A molten metal supply unit for discharging the molten metal;
A cylinder installed below the molten metal supply unit, and a cooling liquid flow forming unit that forms a flow of cooling liquid for cooling the molten metal discharged from the molten metal supply unit in the cylinder. A metal powder production apparatus comprising:
The cooling liquid flow forming unit, a cold却液toward the bottom from the axial direction of the upper portion of the cylindrical body to flow out along the inner peripheral wall of the cylinder to form a flow of the cooling liquid in the cylindrical body,
The coolant flow forming part is
An inflow portion having a first flow path cross-sectional area and allowing the cooling liquid to flow therein;
From the inflow portion toward the lower portion in the axial direction, an enlarged flow path portion in which the flow path cross-sectional area gradually expands to a second flow path cross-sectional area wider than the first flow path cross-sectional area;
A cooling liquid discharge section having a third flow path cross-sectional area narrower than the second flow path cross-sectional area and allowing the cooling liquid to flow out in a film form along the inner peripheral wall. Metal powder production equipment. The metal powder manufacturing apparatus according to claim 1 , wherein the coolant discharge part extends along a concentric direction of the inner peripheral wall of the cylindrical body. A plurality of the coolant flow forming portions;
The plurality of cooling liquid flow forming portions are arranged along a plane orthogonal to the axial direction of the cylindrical body and along a concentric direction of the inner peripheral wall of the cylindrical body. The metal powder manufacturing apparatus of Claim 1 or Claim 2 . A step of forming a flow of the cooling liquid along the inner peripheral wall of the cylindrical body installed below the molten metal supply unit , the cooling liquid forming unit ;
Discharging the molten metal from the molten metal supply unit toward the flow of the cooling liquid, and a method for producing a metal powder comprising:
Wherein in the step of forming a flow of cooling fluid, the cooling fluid forming section, a pre-Symbol coolant downward from the upper portion of the cylindrical body, flows along the inner peripheral wall of the cylindrical body,
The coolant flow forming part is
An inflow portion having a first flow path cross-sectional area and allowing the cooling liquid to flow therein;
From the inflow portion toward the lower portion in the axial direction, an enlarged flow path portion in which the flow path cross-sectional area gradually expands to a second flow path cross-sectional area wider than the first flow path cross-sectional area;
A cooling liquid discharge section having a third flow path cross-sectional area narrower than the second flow path cross-sectional area and allowing the cooling liquid to flow out in a film form along the inner peripheral wall. A method for producing metal powder.

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