JP7062108B2 - Injection nozzle and metal powder manufacturing equipment including it - Google Patents

Description

One aspect of the present invention relates to an apparatus for producing a metal powder, an injection nozzle for injecting cooling water for cooling the metal powder, and an apparatus for producing the metal powder.

Recently, in order to derive the miniaturization, high functionality, diversification and refinement of high-density electronic circuit elements for the dramatic development of the electronic industry, the spread of electronic devices and the improvement of processing speed, chemically It is necessary to prioritize the establishment of a technique for producing fine metal powder that is stable and has excellent conductivity.

As a typical method as such a metal powder manufacturing technique, a rapid solidification process is used. That is, the rapid solidification method is used not only for functional alloy materials such as hard magnetic materials, soft magnetic materials, hydrogen storage alloy materials, and thermoelectric materials, but also for structures such as aluminum alloys, copper alloys, and stainless steel. A method for producing spherical powders for various mechanical parts.

In general, the rapid coagulation method is a water spray method (water), which is a technique in which a fluid or gas is blown at high speed into a molten metal that is discharged when a metal powder is produced by the molten metal, and the molten metal is atomized by the shearing force. Atomization, gas atomization, and centrifugal atomization, which atomizes by the centrifugal force of a cup or disk rotating at high speed, are mainly used.

In the case of a conventional cooling system for powder production, the cooling rate (≤103 ° C) of the metal powder is limited and the quenching effect is insufficient because it is merely a primary cooling action by gas injection or centrifugal spraying. be. SWAP (Spinning water atomization process), which is a method proposed to improve this and obtain a high cooling rate, has been developed so that powder spraying with a fluid and cooling with water can be realized at the same time. ..

However, when the molten metal powder is cooled, it is difficult to achieve a cooling rate above a certain level because the vaporized cooling water generates bubbles or a water vapor layer is formed on the surface of the powder. There is a limit.

In particular, in order to produce an amorphous metal powder, a cooling rate higher than the cooling rate that can be obtained with a conventional metal powder manufacturing apparatus is indispensable.

Amorphous is a term that indicates the state of a substance that does not form crystals and has a disordered and irregular atomic arrangement state, and glass is a typical example of an amorphous substance. Amorphous metals have high strength and excellent ductility due to the lack of crystal orientation, have no self-anisotropic properties, have low electrical resistance, and can be used for various purposes. Is increasing.

Cooling rate acts as an important factor in the production of such amorphous metal powder, which is due to the cooling of metal atoms in the molten metal unless the rate at which the metal melt is cooled is high enough. This is to form stable crystals and form crystalline metal powders.

Conventional metal powder production equipment containing SWAP has attempted to cool with a coolant after atomizing (atomizing) the molten metal, but the cooling rate is too low to form an amorphous metal powder, or Even if an amorphous powder is obtained with a sufficient cooling rate, there are problems that the particle size is irregular and the powder is produced in a shape deviating from the spherical shape. There is a problem that a large amount of gas or cooling water is used to split and cool the molten metal, resulting in high production costs, and research has been conducted on equipment for efficiently producing metal powder with a high amorphous ratio. There is.

Korean Registered Patent No. 10-134156

An object of the present invention is to cool atomized molten metal droplets at a high cooling rate to produce a metal powder having a high proportion of amorphous phases, and to produce amorphous metal powder under various cooling conditions. The purpose is to provide an injection nozzle suitable for manufacturing.

One aspect of the present invention is
An injection nozzle that is fixed by a fixing means and injects cooling water inside a chamber that cools droplets of powdered molten metal.
It is formed by penetrating the base portion (the portion on the root side) connected to the fixing means, the tip portion protruding in the first direction toward the inside of the chamber, and the inside of the base portion and the tip portion. With an injection nozzle holder containing a hollow flow path through which the cooling water flows in the first direction;
A fastening portion coupled to the tip portion, and an injection nozzle tip including an injection portion having a nozzle hole to receive the cooling water supply from the tip portion and inject into the inside of the chamber;
The injection nozzle tip provides an injection nozzle that injects the cooling water in a second direction that faces downward from the first direction.

The flow path is
Formed from the base portion toward the first direction,
It is preferable that the tip portion is formed in a direction lower than the first direction.

The injection nozzle tip preferably includes a guide member that guides the injection coverage angle, which is the angle at which the cooling water flow injected from the nozzle hole spreads, within a certain range.

Further, the injection nozzle tip can be rotated at the tip of the injection nozzle holder to adjust the injection direction.

The length of the injection nozzle holder is preferably 0.1 to 0.7 times the inner diameter of the chamber.

The difference between the injection direction of the injection nozzle tip and the first direction is preferably in the range of 35 to 50 °.

Here, the diameter of the flow path is preferably 10 to 50 times the diameter of the nozzle hole.

When observing the vertical injection angle, which is the smaller angle between the central axis of the fixing means and the injection direction, and the injection direction from the direction along the central axis, the injection direction is the center. A vertical injection angle controller and a circumferential injection angle controller for controlling the circumferential injection angle, which is an angle deviated from the axial direction, can be included.

The vertical injection angle is preferably 10 to 70 °.

Further, it is preferable that the circumferential injection angle is 0 to 90 ° and the injection coverage angle is 15 to 150 °.

The guide member is preferably in the shape of a hollow cylinder or a shape that protrudes from both sides of the nozzle hole in the injection direction to form a slit.

Further, the width of the slit or the distance between the pair of plate-shaped guide members parallel to each other forming the slit is preferably 3 to 4 times the diameter of the nozzle hole, and the width of the slit or the distance between the guide members is preferably 3 to 4 times the diameter of the nozzle hole. The distance between the pair of guide members is preferably 0.3 to 5.0 mm. Here, the slit may be one in which both ends are open or one in which both ends are closed to form a slot, and the slit does not necessarily extend to the same width over the whole, for example, an oval shape or an ellipse. It may be a shape or the like.

The cooling water flows from the base portion in the first direction and flows to the tip portion, and flows from the tip portion to the inside of the chamber through the injection nozzle tip formed in the second direction from the nozzle hole. It is preferable to be sprayed.

Another aspect of the present invention is
A metal powder manufacturing device that cools molten metal after it is pulverized.
With a chamber where the molten metal is cooled internally;
With a molten metal supply unit that supplies molten metal inside the chamber;
With an atomizer that injects a fluid into the molten metal liquid ejected from the molten metal supply unit and splits it;
Including an injection nozzle fixed by fixing means inside the chamber to inject cooling water;
The injection nozzle is
With an injection nozzle holder including a base portion connected to the fixing means, a tip portion protruding in a first direction toward the inside of the chamber, and a hollow flow path penetrating the inside of the base portion and the tip portion;
A fastening portion coupled to the tip portion and an injection nozzle tip including an injection portion with a nozzle hole for injecting cooling water into the chamber;
The injection nozzle holder is connected so as to project in the first direction, and the injection nozzle tip is provided so that the injection direction is downward from the first direction.

The injection nozzles are preferably provided in the range of 2 to 16, and the injection pressure of the cooling water is preferably 30 to 500 bar.

The flow rate of the cooling water is preferably 20 to 200 L / min.

The injection nozzle according to one aspect of the present invention can inject cooling water onto the molten metal droplets scattered by the gas atomizer to destroy the water vapor layer formed on the surface of the scattered molten metal droplets, and the powder can be produced. It can be cooled at a higher rate to produce a metal powder with a high proportion of amorphous phases.

In the injection nozzle, the injection nozzle holder projects in the first direction toward the inside of the chamber, so that the collision point of the molten metal droplets is formed near the injection position of the cooling water, so that the cooling water is injected. It is advantageous that the pressure can be effectively transmitted, the injection nozzle tip has an injection direction formed in a direction facing downward from the first direction, the injection angle can be easily adjusted, and a wide injection angle is formed. ..

Further, since the guide members formed on both side surfaces of the nozzle holes of the injection nozzle can guide the injection coverage angle to a desired range, a cooling environment with cooling water can be stably provided.

It is a front view and the cross-sectional view schematically showing the state which the injection nozzle by one Embodiment of this invention is connected. It is a figure which shows an example of an injection nozzle tip. It is a figure which shows the value of the crystallization enthalpy by the powder particle size in Experimental Examples 1 to 4. It is a figure which shows the result of having analyzed the metal powder produced in Experimental Examples 1 to 4 by an X-ray diffraction (XRD) analyzer.

Prior to describing the invention in detail below, the terms used herein are for the purposes of describing specific embodiments only and are limited only by the appended claims. It should be understood that it does not attempt to limit the scope. All technical and scientific terms used herein have the same meaning as generally understood by those of ordinary skill in the art, unless otherwise stated.

Here, 1) the shape, size, ratio, angle, number, etc. shown in the attached drawings are schematic and can be changed to some extent. 2) Since the attached drawing is illustrated by the line of sight of the observer, the direction and position for explaining the drawing can be variously changed according to the position of the observer. 3) Even if the drawing numbers are different, the same drawing code can be used for the same part.

4) When "comprise, comprises, composing", "have", "consisting of", etc. are used, other parts can be added unless "only" is used. 5) When explained in the singular, it can be interpreted as a large number. 6) Even if the shape, size comparison, positional relationship, etc. are not explained as "about", "substantial", etc., they are interpreted so as to include a normal error range.

7) Even if terms such as "-after", "-before", "following", "following", and "at this time" are used, they are not used in the sense of limiting the temporal position. 8) Terms such as "first," "second," and "third" are used selectively, interchangeably, or repeatedly for convenience of classification and are not construed in a limited sense.

9) The positional relationship between the two parts is "on the top", "on the top", "on the bottom", "next to", "on the side of", "between", etc. As described, one or more other parts may be located between the two parts, unless "immediate" or "straight" is used. 10) When the parts are electrically connected by "-or", it is interpreted that each part is included alone or in combination, but it is electrically connected by "-or" or "either". If so, each part is interpreted alone.

Hereinafter, the components of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a diagram schematically showing a cross section of an injection nozzle for producing a metal powder according to one aspect of the present invention. The injection nozzle for metal powder production includes an injection nozzle holder 32 and an injection nozzle tip 34, and may be provided on the inner wall of the chamber 10 of the metal powder production apparatus by the fixing means 31.

The fixing means 31 is a means for fixing the injection nozzle inside the reactor for producing the metal powder, and the injection nozzle holder 32 can be coupled to the fixing means 31, and the size and shape are not particularly limited, but the fixing means 31 has a central axis. It is preferably configured in the shape of a cylinder.

The fixing means 31 can be installed to fix the injection nozzle to the chamber 10, and is preferably installed near the upper part.

The molten metal melting furnace can be placed in the upper part of the chamber 10, and the molten metal melting furnace is installed or combined so that the melting furnace can be fixed and stably inject the molten metal. An upper plate to be fixed may be further included between the upper part of the chamber 10 and the melting furnace.

The top plate contains fastening holes that can support the melting furnace and allow screws to be attached to the outside so that the melting furnace is fixed. The upper plate is configured to include concentric upper holes in the central portion, and the molten metal can be injected into the chamber 10 through the upper holes. The inner diameter of the upper hole should be formed smaller than the inner diameter of the chamber 10.

When the shape of the fixing means 31 is, for example, a cylinder, one or more injection nozzles can be installed along the circumferential surface. The injection nozzles can be installed in a fixed position, the position may move after installation, or the spacing between the injection nozzles may change.

The position of the coupling portion to which the injection nozzle holder 32 can be coupled can be changed so that the number and position of the injection nozzles coupled to the fixing means 31 can be different. When the fixing means 31 is a cylinder, a connecting portion of the fixing means to which the injection nozzle holder 32 can be connected can be formed along the inner circumferential surface, and the connecting portion includes the shape of a rail or a groove. Can be composed of.

The injection nozzle holder 32 is connected to the fixing means 31 to fix the injection nozzle to the chamber 10 and serves to constantly provide the cooling water supplied from the outside to the injection nozzle.

The injection nozzle holder 32 is configured in the shape of a hollow tube body including a hollow inside, and the cooling water flows through the hollow inside as a flow path 33, and the base portion fixed to the fixing means 31 and the injection. The tip portion includes a tip portion to which the nozzle tip 34 is bonded, and the tip portion can have a shape in which the outer diameter decreases toward the end portion.

The injection nozzle holder 32 is formed so as to have a length of about 100 mm to 120 mm, and the length of the injection nozzle holder 32 is 0.1 to 0.7 times, preferably 0.15 times the inner diameter of the chamber 10. It is double to 0.5 times.

When the injection nozzle holder 32 is shorter than this range, the injection position of the cooling water is farther than the scattering point of the droplets of the molten metal, and the pressure transmission efficiency and the cooling rate can be reduced, so that the particle size is large. The distribution of the powder can be increased, and if the injection nozzle holder is longer than the range, the distance between the injection nozzle holders 32 becomes narrower, so that the molten metal liquid is used when atomizing the molten metal droplets. There is a problem in producing a spherical powder because the drops may collide directly with the nozzle.

Since the injection nozzle holder 32 is formed so as to project inward from the inner wall of the chamber 10, the cooling water to be injected under pressure reduces the distance and required time to collide with the scattered molten metal droplets. .. At this time, since the pressure is efficiently transmitted when the molten metal collides with the cooling water, the water vapor layer formed on the surface of the metal droplets is easily destroyed and the cooling rate becomes very high.

The base portion of the injection nozzle holder 32 is fixed to the joint portion of the fixing means 31, and the rotating shaft that makes it rotatable around the lateral direction perpendicular to the central axis is the fixing means 31 and the injection. It may be provided by a joint with the nozzle holder 32. The injection nozzle holder 32 can rotate around the rotation axis of the base portion to adjust the direction of the injection nozzle holder 32.

In another embodiment of the present invention, the fixing means 31 is formed with a joint portion in the form of a linear or spiral rail having the same protrusion height, and the injection nozzle holder 32 is a joint portion of the fixing means 31. It is equipped with and is movablely connected along the rail. In this way, the base portion can be moved along the joint portion of the cylindrical inner peripheral surface of the fixing means 31, and the injection nozzle holder 32 that can be fixed and driven at a desired position can be used.

The injection nozzle holder 32 is provided so as to extend from the base portion in the first direction. The first direction is the direction toward the inside of the chamber 10, preferably the central axis of the chamber 10, and the flow path 33 formed inside the injection nozzle holder 32 is formed in the first direction from the base portion.

From the tip of the injection nozzle holder 32, the flow path 33 may be formed in a second direction facing downward from the first direction. The flow path 33 may be formed in a curved shape or a curved shape at one or more points inside the injection nozzle holder 32.

When formed in this way, it is preferable that the length of the flow path formed in the first direction by the injection nozzle holder 32 is longer than the length of the flow path formed in the second direction.

FIG. 2 is a diagram schematically showing the structure of the injection nozzle tip 34. The injection nozzle tip 34 injects the cooling water supplied to the flow path 33 of the injection nozzle holder 32 into the inside of the metal powder manufacturing apparatus to cool the molten metal droplets. The injection nozzle tip 34 has a hollow body shape in which a hollow is formed inside, and the discharge port is formed in the front and the inflow port is formed in the rear with respect to the injection direction of the fluid.

The injection nozzle tip 34 is fastened to the injection nozzle holder 32, a fastening portion is formed at the rear, and an injection portion for injecting cooling water is formed at the front. The fastening portion includes an inflow port connected to the flow path of the injection nozzle holder 32 and into which cooling water flows, and includes means for fastening to the injection nozzle holder 32 on the peripheral surface, and may include, for example, a screw thread. ..

When a screw is fastened to the outer surface of the fastening portion of the injection nozzle tip 34, the injection nozzle tip 34 is fastened to a screw thread formed on the inner surface of the flow path at the tip of the injection nozzle holder 32. Since the internal flow path of the injection nozzle holder 32 has a shape bent from the end of the tip portion, the injection direction can be formed so as to face the second direction, which is a direction facing downward from the first direction.

The fastening portion between the injection nozzle holder 32 and the injection nozzle tip 34 may be as follows. That is, it can be fastened to the injection nozzle tip 34 by a thread at the tip of the flow path toward the first direction at the tip of the injection nozzle holder 32, and at the flow path formed in the second direction. It can be fastened to the injection nozzle tip 34.

The first direction is not particularly limited, but is preferably formed in a direction perpendicular to the central axis of the chamber 10 or perpendicular to the inner wall of the chamber 10, preferably an angle formed with the central axis of the chamber 10 or the inner wall of the chamber 10. Is preferably 80 to 100 °.

The second direction in which the flow path is directed from the tip of the injection nozzle holder 32 is different from the first direction in which the flow path is formed from the base portion, and the difference (angle) between the first direction and the second direction is 35 to. It is in the range of 50 °, preferably 35 to 45 °.

When the flow path is linearly configured, the injection nozzle holder 32 can be made to rotate directly in order to adjust the injection direction. However, in this case, since the radius of gyration is large due to the protruding structure of the injection nozzle holder 32, it is difficult to change the injection direction while avoiding collision with the atomized molten metal droplets. Further, when the injection direction of the injection nozzle tip 34 is changed in order to adjust the injection direction, the cooling water is generally injected downward, so that the injection direction in the first direction is downward. In order to change to, a large angle should be displaced in only one direction.

Under the condition that the injection nozzle holder 32 is provided in the direction facing downward from the first direction as described above, the injection angle can be all adjusted up and down, so that even a displacement in a small angle range is wide in the upper part and the lower part. Since the injection angle of the region can be realized, there is a point that it is advantageous for the realization and operation of the equipment.

The injection direction of the combined injection nozzle tip 34 is adjusted by the injection angle controller. The injection angle controller can control the injection direction of the injection nozzle tip 34 coupled to the tip of the injection nozzle holder 32 in the vertical direction and the circumferential direction.

The injection direction of the injection nozzle can be expressed separately as an injection angle in the vertical direction and an injection angle in the circumferential direction, and the injection angle is shown in FIG. The vertical injection angle α means the smaller angle of the injection direction with respect to the central axis of the fixing means 31 or the chamber 10. The vertical injection angle is preferably 10 to 70 °, preferably 30 to 60 °, and more preferably 35 to 45 °.

The circumferential injection angle γ means an angle at which the injection direction deviates from the direction in which the central axis is directed when the injection direction is observed along the central axis, and the injection direction of the cooling water is formed in a cross section perpendicular to the central axis. The projected normal projection can be expressed as an angle between the central axis and a virtual plane passing through the injection port of the nozzle. The circumferential injection angle is in the range of 0 to 90 °, preferably 0 to 65 °, and more preferably 15 to 45 °.

As the injection nozzle tip 34, a nozzle tip having a structure in which the injection portion and the fastening portion can rotate independently of each other can be used. The fastening portion coupled to the tip of the injection nozzle holder 32 is fixed to the injection nozzle holder 32 by a screw thread, and the injection portion of the injection nozzle tip 34 is perpendicular to the fastening portion and a circle by a universal joint or the like. It is rotatable in the circumferential direction, and the injection direction of the cooling water can be controlled by adjusting the injection angle controller to a desired injection direction.

The injection direction of the injection nozzle tip 34 is controlled in the lateral direction after the injection angle in the vertical direction is adjusted along the central axis in a state where the injection direction of the injection nozzle tip 34 is aligned so as to face the central axis. This can be done by rotating the injection direction to adjust the circumferential injection angle.

The nozzle hole 35 formed in the ejection port of the injection nozzle tip 34 can be formed so as to have a diameter of 0.1 to 5.0 mm, preferably 0.3 to 3.0 mm. Since the injection cross-sectional area changes according to the diameter of the nozzle hole 35 of the injection nozzle tip 34, the flow velocity of the injected cooling water can change.

If the diameter of the nozzle hole 35 is smaller than this range, the flow velocity may increase and the molten metal may be further split or it may be difficult to form spherical powder. If the diameter of the nozzle hole 35 is large, the flow velocity decreases. Therefore, there is a problem that the ratio of the amorphous phase of the produced metal powder is low because the cooling effect is lowered.

The hollow diameter of the injection nozzle tip 34 is the same diameter as the nozzle hole 35, smaller than the diameter of the flow path of the injection nozzle holder 32, and the diameter of the flow path of the injection nozzle holder 32 with respect to the hollow diameter of the injection nozzle tip 34. The ratio is 10 to 50 times, preferably 15 to 30 times. When the ratio of the diameter is out of the range, the ratio of the flow rate of the injected cooling water to the flow rate of the supplied cooling water decreases, so that the injection rate of the cooling water decreases or the cooling supplied. There is a difficulty that water must be pressurized at a high pressure, and there is a problem that resistance due to a difference in diameter increases and it is inefficient.

The injection coverage angle β means an angle at which the cooling water injected is spread with respect to the injection direction, and this is shown in FIG. The jet coverage angle means a cone-shaped or fan-shaped jet-shaped central angle. The injection coverage angle β can be adjusted by adjusting the diameter of the nozzle hole 35, the width of the slit, and the like.

In the injection nozzle tip 34, the depth from the protruding surface (tip surface) of the guide member 36 that sandwiches or surrounds the slit to the nozzle hole 35, which is the internal discharge port, is d, and the width of the slit or slotted hole is D2. When the diameter of the hole 35 is D1, the following inequality holds for the coverage angle β.

The injection coverage angle β can be controlled in the range of 15 ° to 150 °, but is preferably formed in the range of 25 ° to 90 °, more preferably 25 ° to 65 °.

The injection unit where the injection nozzle tip 34 is located includes a guide member 36 capable of limiting the flow of cooling water injected from the injection nozzle tip 34 within a certain angle range to guide or control it.

The guide member 36 is formed so as to be formed within a certain range with respect to the injection angle or the injection coverage angle of the cooling water injected from the injection nozzle tip 34 in a conical shape or a fan shape.

One embodiment of the present invention includes a structure having a slit shape protruding from both side surfaces of the ejection port of the injection nozzle tip 34. The injection nozzle tip 34 includes slits protruding on both side surfaces of the discharge port, so that the shape and coverage angle of the injection of the injected cooling water can be adjusted. The cooling water injected from the discharge port of the injection nozzle tip 34 can be injected in a conical shape that is rotationally symmetric with respect to the central axis of the circular nozzle hole 35, and is injected depending on the pressure and flow velocity conditions of the cooling water. It is obtained so that the angle, that is, the size of the coverage angle is different.

In order to set and maintain the size of the injection coverage angle at a desired angle, the protruding slit-forming structure in the injection nozzle tip 34 included in one embodiment of the present invention can be used. Since the slit forming structure (pair of guide members 36) of the injection nozzle tip 34 projects on both sides of the nozzle hole 35, the injection shape of the cooling water to be injected is determined by expanding according to the distance between the slits.

When the angle of the cooling water ejected from the nozzle hole 35 is smaller than the angle between the nozzle hole 35 and the end of the slit, the injected cooling water is ejected inside the slit width (distance between the guide members). When the angle of the cooling water ejected from the nozzle hole 35 is larger than the angle between the nozzle hole 35 and the end of the slit, the injected cooling water collides with the inner surface of the slit and the slit width. A uniform coverage angle can be obtained by spraying within the angle range determined by (the distance between the guide members).

In addition, because the presence of the slit allows cooling water to be injected into a conical injection shape and a flat fan-shaped injection shape, an appropriate injection shape can be used according to the cooling area and centralized cooling requirements. There is an advantage.

The slit spacing of the injection nozzle tip 34 can be in the range of 0.3 to 5.0 mm, preferably in the range of 0.8 to 4.5 mm, more preferably in the range of 1 to 2.5 mm, and the diameter of the nozzle hole 35. It is preferable that the amount is 2 to 6 times, preferably 3 to 4 times.

The shape of the guide member 36 is not particularly limited, and as described above, it is the shape of a parallel plate forming a slit protruding from both sides of the nozzle hole 35, or protruding from the peripheral portion of the nozzle hole 35 and surrounding the periphery. It can be in the form of a hollow cylinder that surrounds it.

When the injection nozzle for metal powder production is used in a metal powder production apparatus, the number and arrangement of the nozzles are not particularly limited, but the number of nozzles is often in the range of 2 to 16, and the spacing between the nozzles is good. Is preferably in the range of 10 to 100 mm.

When the number of nozzles is one, it is difficult to uniformly cool the general molten metal droplets because the cooling water is sprayed only on one surface of the molten metal droplets on which the cooling water falls, and the number of nozzles is 17. In the above case, a chamber 10 having a large diameter should be used, and it is necessary to make the injection angle of each nozzle to be injected different in order to prevent water splashing upward as the number of nozzles increases. There is a problem that the flow rate of the injected cooling water increases and the production cost increases.

If the distance between the nozzles is out of this range, there is a problem in the production of metal powder that must control the crystal structure at a high cooling rate, and it cannot be sufficiently cooled when it is scattered by droplets. Therefore, there is a problem that a plate-shaped unhealthy powder can be produced instead of a spherical powder by hitting the internal chamber 10.

When two or more injection nozzles for producing metal powder are provided, the injection nozzles for producing metal powder can be arranged symmetrically with respect to the central axis, preferably the apex of a regular polygon so as to have a rotationally symmetric shape. It is preferable that each injection nozzle is provided at a position corresponding to.

The supplied cooling water is supplied by a pressurizing device and is supplied from a plurality of cooling water injection nozzles along the flow path of the injection nozzle holder 32, and the flow rate of the supplied cooling water is in the range of 20 to 200 L / min. The pressure of the pressurized cooling water is preferably 30 to 500 bar.

Another embodiment of the present invention is a metal powder manufacturing apparatus including the above-mentioned injection nozzle for metal powder manufacturing.

The metal powder manufacturing apparatus includes an injection nozzle for producing metal powder, a chamber 10 to which the fixing means 31 is coupled, a molten metal supply unit that injects molten metal from the upper part of the chamber 10, and a molten metal supply unit that injects fluid into the molten metal into droplets. Includes atomizer 20 or fluid injection nozzle to split. In the present specification, the fluid injection nozzle is used in the same meaning as the atomizer 20, and is a concept distinguished from the above-mentioned injection nozzle, and is a means for injecting a fluid directly into a molten metal stream to form droplets. Since the cooling effect is insufficient, it is difficult to produce a spherical metal powder.

As the injection nozzle for metal powder production, a nozzle including the above-mentioned features can be used, and the description of the configuration of the injection nozzle is the same as the above-mentioned contents, so it is omitted.

The chamber 10 is a cylinder including a space in which atomized molten metal droplets are cooled, and the shape thereof is not particularly limited, but it is preferably a cylinder or a cylinder having a variable diameter. The chamber 10 has a structure in which the outside and the inside are separated and sealed so that the outside air does not flow into the inside of the chamber 10, and the inner wall is provided with a fixing means 31 for connecting the injection nozzle for producing metal powder. ..

The chamber 10 is composed of an upper chamber and a lower chamber, and the upper chamber and the lower chamber can be used by being connected to each other. At the bottom of the chamber 10, there is a cooled metal powder and the jetted cooling water, there can be a separator for separating the metal powder and the cooling water, and the separated metal powder is dried. The separated cooling water is processed and then pressurized again, and can be circulated and used inside the chamber 10 via the injection nozzle for producing metal powder.

The ratio of the inner diameter to the length of the chamber 10 is preferably 3 to 10 times, preferably 6 to 7 times.

If it deviates from the ratio of the inner diameter to the length, the airflow in the chamber 10 generated along the flow of water sprayed from the nozzle at high pressure does not sufficiently escape, so that the airflow flows backward upward and melts to form an orifice. There may be a problem that the metal liquid that has passed and flowed down is clogged by cooling.

The molten metal supply unit is located at the upper part of the chamber and can inject the molten metal into the inside of the chamber 10, and can be coupled to the upper part of the chamber 10 so that the outside air does not flow into the inside.

The molten metal liquid can be ejected through the molten metal supply unit or flow down by gravity. The composition of the molten metal is not limited, but is predetermined and provided according to the composition of the metal powder to be produced, and the composition can be adjusted so that a high proportion of the amorphous phase is formed when the powder is cooled.

The temperature of the molten metal is not particularly limited, but is formed higher than the melting temperature of the alloy depending on the composition of the molten metal, and can be adjusted to obtain a preferable cooling rate and produce a metal powder having a high proportion of amorphous phases. ..

The melting and heating of the metal is carried out in a melting furnace, and the method of the melting furnace is not particularly limited, and a reflection furnace, a stove furnace, a hot metal furnace, an electric furnace and the like can be used.

The atomizer 20 injects a fluid into a jet stream or a molten metal stream of a molten metal liquid that is jetted or flows down from a molten metal supply unit to split it into fine droplets. The fluid to be injected is not particularly limited, and a liquid atomizing method for injecting a liquid and a gas atomizing method for injecting a gas can be used, and among these, the gas atomizing method is preferably used.

The type of gas used for gas atomization is not particularly limited, but a gas that oxidizes high-temperature molten metal or does not cause a reaction can be used, and an inert gas such as helium, neon, or argon, or reactivity such as nitrogen can be used. A low gas should be used.

The atomizer 20 is located in the lower part of the melting furnace for injecting the molten metal, and can be coupled to the upper hole of the upper plate of the fixing means 31 to split the molten metal liquid injected into the chamber 10.

The fluid injection nozzle used for atomization can use various shapes and numbers of nozzles, and a shape that can split the jet flow of the molten metal liquid with molten metal droplets in the particle size range of the metal powder to be manufactured. And any number of nozzles can be used.

The position and injection angle of the fluid injection nozzle of the atomizer 20 can be adjusted in various ways. The cooling area of the molten metal droplets ejected downward changes depending on the injection angle of the fluid injection nozzle, and the cooling rate and the cooling area may change depending on the position and height provided.

In another embodiment of the present invention, a fluid injection nozzle can be coupled to the upper hole of the upper plate. The fluid injection nozzle may include a through hole coupled to the upper hole through which the molten metal can penetrate and inject, and may include an annular slit-shaped nozzle or injection port that surrounds the perimeter of the through hole.

The fluid supplied from the outside may be gas or cooling water, is filled in a supply pipe formed around the fluid injection nozzle, and then is injected through the annular fluid injection nozzle. The injection shape is conical, and the molten metal liquid injected from the melting furnace can be directly split and at the same time rapidly cooled to form an amorphous metal powder.

In order to cool the molten metal droplets to be injected at high speed and form uniform cooling conditions, the injection direction of the fluid injection nozzle of the atomizer 20 is set to the injection flow of the molten metal liquid (the central axis of the chamber 10 in the illustrated example). ) Is the fluid injection angle a, the distance between the molten metal flow injection nozzle for producing metal powder and the fluid injection nozzle of the atomizer 20, or the difference in height h, the fluid injection angle a and the chamber 10. For inner diameter D
The value of h * tana / D preferably has a value in the range of 0.1 to 0.5.

If it deviates from this range, the scattering angle of the molten metal droplet becomes too large, and the properties of the metal powder produced by dropping the molten metal droplet into a region outside the cooling area of the injection nozzle for producing metal powder are impaired. It may be uniform or the proportion of amorphous phase may be low.

Example 1
For atomization, a gas atomizer is used in which the injection direction (flow liquid injection angle a) of the annular fluid injection nozzle is 5 °, and the vertical injection angle α is 30 ° in the circumferential direction by cooling the droplets. Four injection nozzles were arranged in which the injection angle γ was set to 20 °, the injection coverage angle β was 65 °, and the diameter D1 of the hole (nozzle hole 35) of the injection nozzle tip 34 was 1.0 mm.

Comparative Example 1
A metal powder production device was prepared, which did not include an injection nozzle and consisted of a gas atomizer and cooling water in a static state.

Experimental Examples Experimental Examples 1 to 4: Production of Metal Powder Compared to Examples 1 to 3 and Comparative Example 1, the pressure of the atomized gas is set to 65, 75, 75, 60 bar, respectively, and the flow rate of the cooling water is 35, 40, 40, respectively. , 0 L / min, the water pressure was 110, 180, 180, 0 bar, respectively, and then the temperature of the molten metal to be injected was 1500, 1420, 1400, 1550 ° C., respectively, to produce a metal powder.

The results of Experimental Example 1 to Experimental Example 3 and Comparative Example 1 are summarized in Table 1 below.

Experimental Examples 5-8
In Experimental Examples 1 to 4, the value of crystallization enthalpy according to the powder particle size was measured using a DSC measuring device. The results are summarized in Table 2 below, and the measurement graph is shown in FIG.

Experimental Examples 9-12
The metal powders produced in Experimental Examples 1 to 4 were analyzed by X-ray diffraction (XRD) analysis equipment. The results are shown in FIGS. 4 (a) to 4 (d).

The features, structures, effects, etc. exemplified in each of the above-described embodiments can be combined or modified with respect to other embodiments by a person having ordinary knowledge in the field to which the embodiment belongs. Therefore, the content relating to their combination and modification should be construed as being included in the scope of the present invention.

10 Chamber 20 Atomizer 31 Fixing means 32 Injection nozzle holder 33 Flow path 34 Injection nozzle tip 35 Nozzle hole 36 Guide member

Claims (13)

An injection nozzle that is fixed by a fixing means inside a chamber that cools droplets of powdered molten metal and injects cooling water.
The cooling water is formed through the base portion connected to the fixing means, the tip portion protruding in the first direction toward the inside of the chamber, and the inside of the base portion and the tip portion, and the cooling water is the first. With an injection nozzle holder containing a hollow flow path flowing in the direction;
A fastening portion coupled to the tip portion, and an injection nozzle tip including an injection portion with a nozzle hole that receives the cooling water supply from the tip portion and injects into the inside of the chamber;
The injection nozzle tip injects the cooling water in the second direction facing downward from the first direction.
The injection nozzle tip includes a guide member that guides an injection coverage angle, which is an angle at which the cooling water flow injected from the nozzle hole spreads, within a certain range.
The guide member is an injection nozzle having a shape that protrudes from both sides of the nozzle hole in the injection direction to form a slit . The flow path is
Formed from the base portion toward the first direction,
The injection nozzle according to claim 1, which is formed from the tip portion toward a direction lower than the first direction. The injection nozzle according to claim 1, wherein the injection nozzle tip can be rotated at the tip of the injection nozzle holder to adjust the injection direction. The injection nozzle according to claim 1, wherein the length of the injection nozzle holder is 0.1 to 0.7 times the inner diameter of the chamber. The injection nozzle according to claim 1, wherein the difference between the injection direction of the injection nozzle tip and the first direction is in the range of 35 to 50 °. The injection nozzle according to claim 1, wherein the diameter of the flow path is 10 to 50 times the diameter of the nozzle hole. The vertical injection angle, which is the smaller angle between the central axis of the fixing means and the injection direction; and when the injection direction is observed from the direction along the central axis, the injection direction is the central axis direction. Circumferential injection angle, which is an angle deviated from;
The injection nozzle according to claim 1, further comprising a vertical injection angle controller and a circumferential injection angle controller. The injection nozzle according to claim 7 , wherein the vertical injection angle is 10 to 70 °. The injection nozzle according to claim 7 , wherein the injection angle in the circumferential direction is 0 to 90 °. The cooling water flows from the base portion in the first direction and flows to the tip portion, and flows from the tip portion to the inside of the chamber through the injection nozzle tip formed in the second direction from the nozzle hole. The injection nozzle according to claim 1, wherein the injection nozzle is injected. A metal powder manufacturing device that cools molten metal after it is pulverized.
With a chamber where the molten metal is cooled internally;
With a molten metal supply unit that supplies molten metal inside the chamber;
With an atomizer that injects a fluid into the molten metal liquid ejected from the molten metal supply unit and splits it;
Including an injection nozzle fixed by fixing means inside the chamber to inject cooling water;
The injection nozzle is a metal powder manufacturing apparatus according to any one of claims 1 to 10 . The metal powder manufacturing apparatus according to claim 11 , wherein the injection pressure of the cooling water is 30 to 500 bar. The metal powder manufacturing apparatus according to claim 11 , wherein the flow rate of the cooling water is 20 to 200 L / min.

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