JPS61221312A - Method and apparatus for producing metallic powder by impact atomization - Google Patents

Abstract

PURPOSE:To produce fine-grained metallic powder having high quality by subjecting the downward flow of a molten metal to impact diagonal shearing in downward air flow thereby grinding and atomizing the molten metal under the impact. CONSTITUTION:The pouring flow 2 of the molten metal dropping from a tundish 1 is subjected to the impact diagonal shearing by striking vanes 5 projected on the outside periphery of a striking impeller 4 rotating at a high speed in an arrow rotating direction 19 in the downward air flow 16 shown by the arrow to form molten metal drops or metallic powder 17. The above-mentioned striking vanes 5 are made into the helical cone shape projected on the outside periphery of the impeller 4 rotating around a revolving shaft 14 at 5-85 deg. helix angle alpha with respect to the shaft 14 and are provided with ventilating parts 18 so as not to disturb the downward air flow 16. The scattering direction of the molten drops which are ground is thereby controlled and the metallic powder having good quality is obtd. The much finer formation of the molten drops is also possible by disposing the impeller constituted similarly to the above-mentioned impeller 4 so as to face each other and bringing the molten drops obtd. in the above-mentioned manner into collision against such impellers.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a method and apparatus for producing metal powder in which molten metal is atomized by impact pulverization.

[Conventional technology]

Conventionally, methods for producing powder directly from molten metal include (1) liquid atomization using a high-speed (high-pressure) liquid such as water or oil as the atomizing medium; (2) N2. Gas atomization method that uses high-velocity (high-pressure) gas such as Ar, (3) Sublay atomization method that atomizes molten metal with gas, (4) Release of molten metal that has occluded high-pressure gas into a vacuum to release the occluded gas. Vacuum atomization method in which the metal is atomized by expansion; (5) Molten metal is injected into a high-speed rotating body such as a disk or bowl-shaped drum and is dispersed by centrifugal force. Or arc discharge,
There are various methods such as centrifugal atomization, which uses an electron beam, plasma, laser, etc. as a heat source to melt the base material while rotating and scattering it due to centrifugal force.

In recent years, rapid solidification with a microstructure in which amorphous metal powder or alloying elements are dissolved in a highly supersaturated solid solution has been used as raw material powder for powder metallurgy, paint pigments, electromagnetic applications, catalysts, thermal spraying, overlay applications, etc. There is a need to produce high-quality metal powder at low cost. However, the method for producing metal powder as described above has the following problems and cannot satisfy these requirements.

That is, (1) In the liquid atomization method, contamination due to liquid occurs.

(2) In the gas atomization method, there is a limit to the injection gas velocity, so it is difficult to produce fine powder with an average particle size of 504 m or less, and the particles produced may form satellite build-ups or trap the spray gas. There are other problems.

(3) The spray atomization method is difficult to apply to high melting point metals due to the material of the spray nozzle.

(4) In the vacuum atomization method, the types of molten metal and storage gas are limited, and the cooling rate of particles is 102°K/S.
It is slow at about eC and has the problem of trapping storage gas.

(5) In the centrifugal atomization method using a rotating disk, slipping occurs between the disk or bowl-shaped disk and the molten metal, and the average particle size is In addition, the base material rotating centrifugal atomization method is limited by the processing of the base material and the rotation mechanism, so the average particle size is only about 100 μm.
Only about 400 ILm of powder has been obtained, and there are other problems such as component segregation in the base material.

For each of the above methods, rotary impact spraying involves applying an impact force such as a gear-shaped or impeller-shaped impeller with protrusions or recesses, or an impeller such as a rod or hammer-shaped striking arm to crush the injected flow of molten metal. According to the law, the impact energy applied to the molten metal increases in proportion to the mass of the impeller and the square of the rotational speed, so mass production by increasing the size of the equipment is the key. Further, since it becomes possible to atomize the particles by increasing the rotational speed, it becomes possible to achieve a cooling rate of about 105 to 108°/SeC as a result of the atomization.

This rotational impact spraying method was used in the old days of Bee Ken Eye O ψ Nis Report (B, 1. O, S).

Report No. 706, No. 1223) (D, P, G,) (rotating disk)
In recent years, Powder Metallurgy International (Powder Metallurgy I
nt,.

Vol, l 1.1979. PI3), JP-A-58-1
It can be found in Japanese Patent Publication No. 53707, Japanese Patent Publication No. 58-35563, and Japanese Patent Application Laid-open No. 197206/1983.

(a) As shown in Figure 8, in the rotating disk method, the molten metal is dropped while being surrounded by a cone-shaped water stream, and a blade installed on a horizontal disk is rotated in the horizontal direction to crush it by impact. However, it is not possible to produce clean metal powder due to water contamination.

(b) The method described in Powder Metallurgy International and JP-A-58-153707 rotates a convex rotating body in the form of a spur gear in the horizontal direction, as shown in FIGS. 9 and 10, respectively. In this method, molten metal is dropped and injected from the direction of rotation and is crushed by impact.

Therefore, as the circumferential speed increases, the velocity and volume of the airflow released in the horizontal direction increases, and this airflow scatters the falling injection flow of molten metal.

(c) Japanese Patent Publication No. 5B-35563 and Japanese Unexamined Patent Publication No. 1983
The method described in Japanese Patent No. 197206 is shown in FIGS. 11 and 12, respectively.

An impact body with an underwater rotating shaft is rotated vertically, and melt-resistant metal is injected vertically and crushed by impact. In this case, the air flow released in the radial direction of the rotating cylinder due to the rotation of the #'I bombardment body scatters the injection flow of molten metal, so its installation is limited to the α-vacuum tank.

[Problem that the invention seeks to solve]

The main parameters when producing metal powder by rotary impact atomization are the radius of the striking vanes, the striking! ! ! There are various factors such as the amount of balls in the blade, the shape and number of the striking blades, the rotational speed (peripheral speed) of the striking blades, and the material of the striking blades, but the above-mentioned rotary impact spraying method and its apparatus have the following problems.

(a) Rotation of the striking blades causes centrifugal force to act in the radial direction of the rotating cylinder, creating airflow. If this airflow is discharged toward the molten metal injection stream, there is a problem in that the molten metal injection stream is blown away by the airflow before reaching the rotary impeller. In particular, this becomes a serious problem when the radius or rotational speed of the impeller is increased, or when pre-spraying using other airflows is used in advance of impact spraying. Therefore, in the known method and device, the height of the protrusion of the striking blade, the depth of the four parts, or the length of the striking arm are made as short as possible to suppress the generation of air current. In addition, the impeller is rotated horizontally to emit airflow in the radial direction, which is the horizontal direction, and molten metal is injected from the vertical direction to avoid scattering due to the airflow.

Furthermore, it is provided in a vacuum.

(b) In the above-mentioned known rotary impact spraying method and device, the crushed droplets are scattered over a wide range, often in the vertical direction where the molten metal is injected, and the molten metal is scattered on the ceiling of the collection tank (atmosphere maintenance tank). Not only does it adhere to the bottom of the injection device and disturb the injection flow and reduce the recovery yield of powder, but the adhering material flakes off and damages the striking blades. Further, the scattered droplets in this direction of rotation are coarse particles.

(c) The known rotary impact spraying method and device are comprised of one impeller having a protrusion.

Thus, once a molten metal droplet is impact-shattered.

Even though it is still in a molten state, it scatters and is not subjected to impact pulverization again.

[Means for solving problems]

In order to solve the above-mentioned problems (a), (b), and (c), the present invention basically consists of: A) generating a downward air flow and treating the falling flow of molten metal therein;

B) The falling flow of molten metal is obliquely cut by an impeller that is inclined to the falling flow.

C) A second blowing blade for re-pulverization is provided to further improve the crushing effect.

I decided to do so.

In the conventional method and apparatus shown in FIGS. 8 to 12, in order to solve the problem that the airflow caused by the rotating striking blade scatters the molten metal injection flow, the longitudinal direction of the striking blade is set relative to the axis of its rotation locus. By directing the airflow produced by the striking vanes downwards by twisting tangentially,
It can be solved.

In the rotary percussion spray method, it is most efficient to impact and crush the molten metal stream horizontally from the α side in front of the rotary percussion blade.

However, with such a striking blade, the faster the rotation speed is, the more opportunities there are to crush and spray the molten metal on the L side and front upper side of the striking blade facing the molten metal injection flow.
A problem arises in that the molten metal is scattered in the direction in which the molten metal is injected, and the scattered droplets are coarse particles. Therefore, in the present invention, the falling flow of molten metal is obliquely cut. That is, as described above, the striking blades are twisted into a helical shape, and the outer periphery of the striking blades is inclined in the axial direction, so that the striking blades are shaped like helical bevel teeth and have a twist angle with respect to the axis of rotation. A falling flow of molten metal was supplied to the sloped area of the outer edge. As a result, scattering in the injection direction is eliminated, and the scattering direction of the crushed and sprayed droplets can be directed downward. Furthermore, the crushing efficiency was increased by re-pulverizing the powder using a second rotating blowing blade installed in parallel with the blowing blade.

Also, a vent was provided in the striking blade so that the suction airflow could be quickly discharged through the vent.

[Effect]

According to the present invention, the injection flow of molten metal is pulverized by impact without being discharged by the rotation of the striking blade or being scattered by the air current. Furthermore, it is possible to prevent the impact-pulverized droplets from scattering in the vertical direction or in the injection direction of the molten metal. Furthermore, since it is re-pulverized using a plurality of impellers, it can be made into fine particles.

In addition, by providing a ventilation section in the striking blade, the suction airflow passes through quickly, which not only improves the impact crushing efficiency, but also improves the airflow cooling of the striking blade and reduces the wind pressure (windage loss) on the striking blade. can be measured, so the output of the rotary power source can be reduced.

〔Example〕

Embodiment 1 FIG. 1 shows an example of a striking impeller 4 used in carrying out the method of the present invention, in which (a) is a plan view and (b) is a perspective view. The striking blade 5 projects from the impeller 4 and includes a striking front surface 6, a striking peripheral part 7, a striking rear surface lO1, a striking top surface 11, and a striking bottom surface 1.
Consisting of 3. When the striking blade 5 is rotated, the striking peripheral part 7 is connected to the rotation axis 14 such that the rotation locus of the striking peripheral part 7 of the striking blade 5 or the extension line 8 of the striking peripheral part substantially forms a conical shape. tilt at any angle. Hereinafter, this angle will be referred to as an inclination angle β. Tilt angle β
approximately corresponds to 172 full angles of the apex angle of the virtual cone.

Moreover, the impeller is constructed by twisting the striking bottom surface 13 of the striking blade 5 so that its rotational phase is delayed.

Specifically, the striking blade 5 is such that when the striking blade is rotated, the striking peripheral edge 7 or the extension 8 of the striking peripheral edge is substantially conical, and the striking blade extends from the center 9 of the striking peripheral edge to the rotation axis 14. It has one longitudinal direction when projected onto a plane perpendicular to the perpendicular line 15, which is twisted in a helical shape with respect to the rotating shaft 14, and the striking bottom surface 13 is It is configured to rotate with a phase delay relative to the upper surface 11.

The angle at which the striking blade 5 is twisted in a helical shape with respect to the rotation axis is called a twist angle α.

As shown in F, the striking periphery is inclined so that the rotation locus of the striking periphery or an extension of the striking periphery forms a conical shape, and the striking bottom surface rotates with a lag in phase with respect to the striking top surface. By twisting the striking front surface and providing a striking vane, the striking impeller 4 sucks in airflow from the striking top surface or peripheral part, which rotates with the phase leading, and from the striking bottom surface, which rotates with the phase delayed, in the direction of the rotation axis. The airflow is released almost downward. Therefore, by injecting the molten metal into the peripheral edge of the striking blade, the molten metal injected flow riding on the suction airflow can be effectively obliquely cut and pulverized and sprayed at the peripheral edge of the rotating striking blade. At this time, if the angle at which the injection shaft 3 of the molten metal is incident on the periphery of the striking blade is θ, the droplets crushed and sprayed at the periphery of the striking blade will reach the periphery of the striking blade with a reflection angle θa that is symmetrical to the incident angle θ. It scatters in a concentric conical shape centered on the tangent to the direction of rotation of the part. This not only reduces the scattering of droplets in the vertical direction or in the direction of the injection axis of the molten metal, but also completely prevents it. The incident angle θ is not limited.

Therefore, it is not necessary to limit the inclination angle β of the striking blade 5, which makes almost a full angle with respect to the incident angle 0, and the peripheral edge of the striking blade 5 can be rotated from the front side to the back side as shown in FIG. If the outer circumferential surface of the peripheral edge of the striking blade is formed into a linear shape by chamfering the radius to shorten it or making it thinner, it is possible to avoid crushing and spraying with the outer circumferential surface, and to reduce the crushing by only the diagonal cutting action. It can be done.

Note that the shape of the peripheral edge of the striking blade does not necessarily have to be straight, and may be somewhat uneven, or arcuate, or curved.
It may be arcuate, as long as the rotation locus of the striking peripheral edge or its approximate extension line is approximately conical.

Furthermore, when the torsion angle α of the striking blade 5 is less than 5 degrees, airflow is released in the radial direction of the striking blade due to centrifugal force, and the molten metal injection flow is scattered in the L space of the virtual rotating cone forming surface. will begin to receive On the other hand, the twist angle α is 8
If the angle exceeds 5 degrees, the pulverized metal particles will be crushed exclusively at the peripheral edge of the striking blade or the back surface of the striking blade, and the pulverized metal particles will become coarse.

- Therefore, in order to more efficiently apply a lateral impact to the front of the impact or the periphery of the impact, the torsion angle α should be in the range of 5 to 85 degrees.

Next, an embodiment of the present invention using one impeller 4 having a striking blade 5 (hereinafter referred to as a single type) will be described.

FIG. 3 is a conceptual diagram of the main parts of an embodiment of a device that can suitably carry out the present invention using one impeller 4.

In FIG. 3, one impeller having one or more striking blades 5 is supported by a bearing and rotatably provided by a drive device, and is provided with a housing (not shown) for maintaining the atmosphere or collecting powder. surrounded by. Further, if necessary, a molten metal supply device, such as a tundish 1, is also surrounded by the housing.

Here, the phase of the striking bottom surface 13, which has an arbitrary inclination angle β with respect to the rotation axis 14 and has a long rotation radius of the truncated cone, is delayed so that the rotation peripheral edge of the striking blade 5 forms a truncated cone. The impeller 4 was constructed by providing a striking blade having a twist angle α of 5 to 85 degrees so as to rotate.

When the blade 114 is rotated, the impact surface ll of the truncated cone of the impact blade 5 having a short rotation radius and the impact peripheral portion 7 rotate in advance to suck in the airflow 16 and discharge it downward from the impact bottom surface 13. do. When the molten metal is injected toward the striking peripheral part of the rotating striking vane ff15, the flow 2 becomes the airflow 16.
The metal is guided to the striking periphery of the rotating striking blade 5, is subjected to a lateral impact, is cut obliquely, is pulverized and sprayed, and is scattered as molten metal droplets or metal powder 17.

At this time, since the striking blade 5 is provided with an arbitrary inclination angle β so that its peripheral edge forms a truncated cone, the molten metal droplets or metal powder 17 crushed and sprayed at the striking peripheral edge 7
is an incident angle of 0 in the injection direction of the molten metal with respect to the striking peripheral portion 7.
The molten metal is scattered in a concentric conical shape centered on the tangent of rotation from the collision impact pulverization point of the impact peripheral edge 7 with the direction of the reflection angle Oa symmetrical to , thereby reducing the scattering in the direction of rotation or in the direction of the injection axis 3 of the molten metal. Or it can be prevented.

Next, an example will be described in which one impeller shown in FIG. 3 was rotated in the horizontal direction under the following conditions, and molten Sn at 280° C. was injected gravity-dropped from the direction of rotation using a 2 mmφ nozzle and pulverized by impact.

Number of blowing blades: 8 (equally spaced every 45 degrees) Inclination angle of hitting blades: 2 degrees, 5 degrees, 25 degrees, 45 degrees, 75 degrees, 85 degrees, Twisting angle of hitting blades: 0 degrees, 5 degrees, 20 degrees, 30 degrees, 45
degree, 65 degrees, 85 degrees, 90 degrees, Distance from the rotation axis to the impact crushing point of the striking blade (rotational impact radius): 160 mm Rotational circumferential speed of the impact crushing point of the striking blade (rotational impact circumferential speed): 1
00m/sec Material of the blowing blade: Mild steel Ventilation holes on the surface of the blowing blade that receives wind pressure: Yes (area is 172 mm on the blade surface) or not Rotating distance from the impact crushing point of the hitting blade to the ceiling of the spray chamber: 300 mm 5th Figure 6 shows the relationship between the inclination angle of the blowing blade and the ceiling adhesion row with respect to the amount of molten metal injected.
As is clear from the figure and Fig. 6, as the inclination angle of the striking blade increases, the amount of adhesion to the ceiling of the spray chamber decreases, and when the inclination angle is 75 degrees or more, no adhesion to the ceiling occurs. It can be seen that by changing the inclination angle of the striking blade with respect to the injection direction, the scattering direction of droplets or metal powder after impact pulverization can be controlled. It is also seen that the sharpening impact pulverization is effectively carried out when the torsion angle of the striking blades is 5 to 85 degrees, and further atomization is achieved by providing ventilation holes in the striking blades.

Example 2 A first percussion impeller and a second percussion impeller are arranged side by side facing each other, and the molten metal can be further atomized by impact pulverization between the impellers. can. Specifically, two impellers are used. That is, a first striking impeller in which the above-mentioned striking vanes have an inclination angle and a weeping angle, and the rotation locus of the outer periphery of the striking peripheral edge or an extension of the striking peripheral edge is substantially conical; The rotation locus of the outer periphery of the striking blade is cylindrical, and the angle of rotation is 5 to 8 with respect to the rotation axis.
A second striking impeller having a twist angle of 5 degrees is used, and the striking impeller's circumferential edge of the first striking impeller and the striking impeller's circumferential edge of the second striking impeller are arranged to face each other, and the striking impeller is identical to each other. rotate in one direction or the other. In this way, when molten metal is injected into the rotating cone forming surface of the first striking impeller and cut obliquely at the peripheral edge of the first striking impeller of the first striking impeller, it is pulverized and sprayed by a lateral impact, and the incident angle θ The scattered droplets are scattered in the tangential direction with a reflection angle θa symmetrical to , and these scattered droplets are efficiently crushed and sprayed again at the peripheral edge of the striking impeller of the second striking impeller rotating oppositely. The torsion angle of the striking blades of the second striking impeller is preferably 5 to 85 degrees for the same reason as described above. Second
The twist angle α and rotation direction 19 of the striking impeller 21 of the striking impeller 20 are determined according to the discharge direction of the airflow 15 of the striking impeller 4.

FIG. 4 is an example of a conceptual diagram of a main part of an apparatus for carrying out the present invention, in which a percussion impeller and an impact impeller are arranged so that the percussion blades face each other.

A first striking impeller 4 and a second striking impeller 2 shown in FIG.
0 as shown in Table 1, and the striking blades are arranged at intervals of 5 m.
280°C Sn and 1600°C molten stainless steel (SUS304) were first struck with a 4mmφ nozzle. It was injected from the direction of rotation toward the periphery of the impeller and pulverized by impact. In addition, the injection position of the molten metal is determined from the line connecting the respective rotational axes of the first striking impeller and the second striking impeller when the rotation impact radius of the striking impeller is 160 mm and with respect to the rotation direction. The point was set 20 degrees behind.

FIG. 7 shows the relationship between the rotational impact circumferential speed of the striking blade and the median diameter of the sieve fraction determined from particle size analysis.

As is clear from Table 1 and Figure 7, the metal powder is atomized in inverse proportion to the rotational impact circumferential speed of the striking blade, and it can be seen that the twin method is more atomized than the single method at the same peripheral speed.

By hollowing out the striking blades 5 and 21 of the first and second impellers and providing ventilation m18, it is possible to reduce the wind pressure (windage loss) and centrifugal force that the blades receive during rotation, and airflow cooling. can be promoted, and rotational power can be made advantageous.

The distance between the rotating cylindrical surfaces of the striking blades of the impellers facing each other is appropriately selected from the radius, shape, number of installed impellers, and arrangement of the impellers provided on the impeller. A range of approximately 100 mm is preferable, but it is also possible to arrange two overlapping blades under the condition that the facing blades do not collide with each other. Further, in addition to the case where the radius and shape of each impeller (including the striking blades) are the same and the number of revolutions (same circumferential speed) is the same, it is also possible to crush the molten metal under the condition that all of them are %.

As shown in FIG. 7, the metal powder produced by the rotary impact atomizer becomes more atomized as the circumferential speed of the impact blades increases, and as the number of impact blades increases (the
The smaller the ratio of the short side to the long side (longitudinal direction) of the striking blade, and the smaller the diameter of the molten metal injection stream, the more likely it is to be pulverized, and at the same time it is rapidly cooled. This flow of molten metal may be a columnar flow that falls by gravity from a nozzle made of refractory material, or may be dispersed droplets that have been previously atomized by other methods such as gas atomization.

Further, the atmosphere can be freely selected, and non-oxidized powder can be obtained by creating an atmosphere that does not contain an oxygen source, or by applying the striking blade constructed as in the present invention in a vacuum or reduced pressure atmosphere. It is also possible to obtain metal powder. Further, the striking blades may be formed integrally with the impeller or may be detachable, and the material thereof may be appropriately selected from metal, ceramics, graphite, or a composite material thereof. The blowing blade is a turbo type blower, pressure 1ii
As seen in propellers, the shape of the blades may be, for example, reaction-shaped or crescent-shaped, and they are installed linearly or curved, and the rotation locus of the peripheral edge is not only truncated, but also shaped like a truncated cone. It may be conical or hyperbolic. The axis of rotation is not limited to the vertical direction;
It can be installed horizontally or at any angle between vertical and horizontal.

〔Effect of the invention〕

The method for producing metal powder and the apparatus for producing the same according to the present invention are configured as described above, so that by rapid cooling through atomization, special structures such as amorphous metal powder or a fine structure with supersaturated solid solution of alloying elements are formed. It is possible to produce high quality metal powder with a unique structure.

In addition, by impact-pulverizing the molten metal injection stream with oblique cutting impact using the impact blades whose impact periphery forms a substantially conical shape, the scattering direction of the crushed droplets can be controlled, and the droplets can be roughly Since the particles can be efficiently collided with the striking blades of the second impeller disposed opposite to each other, further atomization can be achieved. Furthermore, by providing a ventilation section in the striking blade, it is possible to promote airflow cooling in addition to water cooling and reduce wind damage, which also makes it possible to increase the size of equipment, reduce power, and mass-produce powder. be effective.

[Brief explanation of the drawing]

1 and 2 show an impeller according to an embodiment of the present invention, respectively (a) is a plan view, (b) is a perspective view, and FIG. 3 is a main part of a single type device according to an embodiment of the present invention. 4 is a conceptual diagram of the main parts of the twin-type device according to the embodiment of the present invention, and FIG. 5 shows the inclination angle of the striking blade and molten metal when the device shown in FIG. 3 is used. 6 is a graph showing the relationship between the amount of ceiling deposited and the amount of injection, and FIG. Graphs showing the relationship between the rotational impact circumferential speed of the striking blade and the median diameter of the metal powder when using the apparatus shown in Figure 4 and Figure 4. Figures 8 to 12 show the conventional rotary impact spraying method and its equipment. It is an explanatory diagram showing an outline. l... Molten metal supply section (tundish) 2... Molten metal injection flow 3... Molten metal injection shaft 4... Strike impeller 5... Strike vane 6... Front side of the strike vane 7...Peripheral edge of the striking blade 8...Extension line of the peripheral edge of the striking blade 9...Center of the peripheral edge of the striking blade 10...Back surface 11 of the striking blade 12...L side 12 of the striking blade ... Front side of the striking blade 13... Bottom surface of the striking blade 14... Rotating shaft 15... Line 16 drawn from the center of the outer surface of the striking blade to the rotating shaft 16... Air flow 17 ... Molten metal droplets or metal powder 18 ... Ventilation section l9 ... Rotation direction 20 ... Second blowing impeller 21 ... Striking blades 22 of the second blowing impeller ... Second
Rotation axis α of the striking impeller...Twist angle β of the striking vane...Inclination angle of the striking vane 0...Incidence angle of total melt bending

Claims (1)

[Scope of Claims] 1. A method for producing metal powder by impact atomization, characterized in that a falling flow of molten metal is cut obliquely by impact in a downward air flow. 2. A striking impeller that rotates at high speed around a rotating shaft, a helical bevel-shaped striking vane that protrudes from the outer periphery of the impeller and has a helical angle of 5 to 85 degrees with respect to the rotating shaft, and the striking vane. 1. An apparatus for producing metal powder, comprising a metal supply section that supplies a falling flow of molten metal to a peripheral portion. 3. A first impact impeller that rotates at high speed around the rotation axis;
a helical bevel-shaped first striking impeller protruding from the outer periphery of the first striking impeller and having a helical angle of 5 to 85 degrees with respect to the rotation axis; a second percussion impeller that is installed and rotates at high speed around the rotational axis; and a helical spur tooth-shaped impeller that protrudes from the outer periphery of the second percussion impeller and has a helical angle of 5 to 85 degrees with respect to the rotational axis. A metal powder manufacturing apparatus comprising: a striking blade; and a metal supply section that supplies a falling flow of molten metal to the peripheral edge of the first striking blade. 4. The metal powder manufacturing apparatus according to claim 2 or 3, wherein the striking blade is provided with a ventilation section.