TWI618589B - Device and method for manufacturing material particles - Google Patents

Abstract

The invention discloses a method and a device for manufacturing a material powder, comprising: providing a device for manufacturing a material powder, comprising: a feeding unit for continuously supplying a raw material; and an atomizing tower, wherein the atomizing tower is provided with a a high frequency induction heating unit that heats one end of the material and melts it into a droplet of material; a plasma heats the jet unit, which supplies a high temperature to the droplet of the material, and blows the droplet of the material to make the material Droplet atomization; and a powder collection unit for collecting the material powder formed by the natural sedimentation of the atomized material droplets. According to the present invention, the particle size distribution range of the material powder can be reduced to provide a material powder having a uniform size.

Description

Method and device for manufacturing material powder

The present invention relates generally to the fabrication of powder materials; in particular, the present invention relates to techniques for making powder materials with uniform particle size.

Material powder is an important manufacturing material in today's manufacturing industry, for example, in the increasingly popular 3D printing technology, flat inkjet printing, screen printing, and imprint technology. Imprinting) and so on. The use of inks containing the desired printed material powders in various printing techniques, wherein the material powder to be printed will critically affect print quality, particularly in electronic circuit products. The uneven thickness of the metal powder will cause difficulty in controlling the wire diameter of the electronic circuit, and even cause a short circuit or an open circuit, thereby causing component failure. Techniques for transferring powders for manufacturing materials include mechanical pulverization, plasma rotary electrode method, electrode induction smelting gas atomization method, and plasma torch method. In particular, electrode-induced smelting gas atomization (EIGA) is a widely used method for metal powder materials, which uses a high-speed gas stream to spray molten metal droplets. 1 shows a conventional electrode induction smelting gas atomization device 100. When the induction coil 101 is heated to melt the metal material, the molten metal droplets are blown by the high pressure gas jet device 102 to break into minute droplets. The metal droplets are solidified by cooling and settled to a collection dish. However, the metal powder produced by the conventional EIGA device has a wide particle size distribution, and the metal powder produced by further screening needs to be applied to the printing ink, and even the metal powder produced needs to be further refined, and the throughput is produced. Low efficiency. In addition, high-speed airflow blowing consumes a large amount of gas, which is expensive to manufacture and does not meet the production cost reduction required by the printing technology. Therefore, there is a need for an apparatus and method for producing a fine and uniform particle size material powder to solve the problems of low production throughput and high manufacturing cost.

The present invention provides an apparatus and method for producing a material powder for producing a particle size homogenizing material powder to reduce the particle size distribution range of the material powder. An embodiment of the present invention provides an apparatus for manufacturing a material powder, comprising: a feeding unit for continuously supplying a raw material; and an atomizing tower, wherein a high frequency induction heating unit is disposed in the atomizing tower, Heating one end of the raw material and melting it into a droplet of material; a plasma heating the jetting unit, which supplies a high temperature to the droplet of the material, and blowing the droplet of the material to atomize the droplet of the material; A powder collection unit for collecting material powder formed by natural sedimentation of the atomized material droplets. Another embodiment of the present invention provides a method of producing a material powder comprising continuously supplying a raw material to an atomization tower at a steady rate; heating one end of the raw material in the atomization tower and melting it into a material a droplet; providing a high temperature to the droplet of the material, and blowing the droplet of the material to atomize the droplet of the material; and naturally depositing the droplet of the atomized material to form a powder of the material. According to the present invention, the particle size distribution range of the material powder can be reduced, and a material powder having a uniform size can be provided, which further simplifies the manufacturing process and further provides a manufacturing flux.

While the invention has been described and illustrated with reference to the embodiments of the invention It will be understood by those skilled in the art that various changes and alternatives may be made without departing from the true spirit and scope of the invention as defined by the appended claims. In order to solve the problem that the material powder manufacturing process is complicated and the particle size distribution is uneven, the present invention provides an apparatus and a method for manufacturing a material powder, which can concentrate the particle size distribution of the material powder without further screening of the material powder. , or refined material powder, to simplify the manufacturing process, and further increase the material powder market usage and increase throughput. For example, a powder material having a uniform particle size is suitable for use in printing inks, and when used for printing metal lines, it helps to control line width and circuit quality. 2 shows a schematic diagram of an apparatus 200 for making a material powder, wherein the feed system 201 continuously supplies the feedstock 202 into the atomization tower 203 at a steady rate. The high frequency induction heating unit 204 and the plasma heating jet unit 205 are disposed in the atomization tower 203, wherein the high frequency induction heating unit 204 heats one end of the raw material 202 to melt it into material droplets, and the feeding system 201 continuously advances the raw material. 202, the molten material droplets are introduced into the plasma heating jet flow unit 205, and the plasma heating jet flow unit 205 injects the material droplets to atomize them. Finally, the atomized material droplets are separated from the heating spray unit 205 and then cooled, and are coagulated by the cohesive force of the fine material droplets and solidified to form a powder, which naturally settles in the powder collecting unit 206. According to the present invention, after the raw material is melted into a droplet shape, the droplets of the material are continuously heated by the plasma during the atomization process, which can improve the fluidity of the droplets and increase the degree of atomization during the atomization process, thereby effectively reducing the particles. size. A cooling system (not shown in the drawings) is disposed in the atomization tower 203. For example, a cooling water line is surrounded in the inner side of the atomization tower, so that the temperature in the atomization tower 203 is stably maintained at 30 ° C -50 ° C. To stabilize the cooled atomized particles. The raw material may be a metal wire or a ceramic wire having a wire diameter of 5 mm to 16.5 mm, preferably 6 mm or more, and a feeding system 201 having a feed speed ranging from 5 to 15 mm/sec. The raw material 201 may also be other forms of solid materials, including rod-shaped materials, irregular block materials or powder materials, and the like. Before the feedstock enters the atomization tower 203, the chamber is evacuated, for example, to a vacuum of 10 ^-4 mbar. An inert gas which does not react with the material to be powdered, such as argon, helium and/or nitrogen, is supplied via the gas inlet 207. An inert gas is introduced to maintain a pressure of about 0.7 psi in the chamber of the atomization tower 203. The high frequency induction heating unit 204 heats one end of the raw material 102 by an induction coil having a frequency ranging from 150 kHz to 1000 kHz, preferably between 150 kHz and 400 kHz, and having a power of 27 kW to 100 kW, in such a condition. The raw material is rapidly melted into droplets. Figure 3 shows a schematic view of a plasma heated jet flow unit 205 of the present invention. The plasma heating jet unit 205 is configured in a ring shape and includes a cathode 2051, an anode 2052 and a cyclone system 2053 surrounding the molten material droplets. The plasma heating jet unit 205 continues to heat the droplets of the molten material, and the cathode 2051 and the anode 2052 form a plasma ring with a power of 40 kW - 100 kW, so that the inert gas forms an inert gas plasma, and the cyclone system 2053 makes the inert gas The gas plasma blows the droplets of molten material to impact the surface of the material droplet at a high speed to heat the material droplets again to reduce the viscosity coefficient of the material itself and to blow into fine droplets, that is, an atomization process. A high pressure inert gas is introduced into the plasma jet unit 205 at a flow rate of 100 L/m to 500 L/m, and the inert gas pressure is 10 kg/m ² -20 kg/m ² . The blown fine material droplets leave the plasma heating jet unit 205, solidify by cooling, and naturally settle to the powder collecting unit 206. The annular plasma heating jet unit 205 can uniformly heat the range surrounded by the cathode 2051 and the anode 2052. For the droplets of the material which have been formed into a molten state, since the viscosity coefficient is low, it is easy to deviate from the central axis during the atomization process. Compared with the conventional plasma gun atomization technology, the plurality of plasma guns must be focused on the material droplets to atomize the material, and the annular plasma heating jet unit 205 does not have the problem of difficulty in focusing. Since the material droplets are continuously heated and atomized during the high-speed high-pressure inert gas injection, the extremely high temperature material droplets can make the fine droplets generated by the atomization process smaller and uniform. The powder occupancy of the particle size of 63 μm or less is greatly improved. In one embodiment, the cyclone system 2053 includes a De Laval nozzle with a gas velocity of about 1 Mach-20 Mach at high speed to cause the metal droplets to form a finer powder. The material powder formed according to the present invention is spherical, fine in size and uniform in particle size, for example, the metal powder produced has an average particle diameter of 50 μm - 100 μm, and the powder having a particle diameter of more than 150 μm is less than 10%. An embodiment of the present invention is manufactured by the following procedure: (1) evacuating the atomization tower 203 to 10 ^-4 mbar; (2) introducing argon gas into the atomization tower 203 via the air inlet 207, when fogging is performed The pressure of the tower 203 reaches 0.7 psi; (3) the high frequency induction heating unit 204 is controlled by the controller to pass argon gas, and the current is adjusted and the high frequency ignition device is activated, the high frequency induction heating unit 204 is turned on, and the argon flow rate is adjusted. 200L/m, current is adjusted to 300A; (4) Continuously turn on the high-frequency induction heating unit 204, the induction coil copper used is about 6.8mm in outer diameter, the distance from the upper edge of the coil to the lower edge is about 61mm, and the inner diameter of the coil is about 22mm, the current is adjusted to 700A; (5) the titanium alloy wire having a wire diameter of 6.5 mm is fed into the atomization tower 203 by the feeding system 201; (6) after the titanium alloy wire passes through the high frequency induction heating unit 204, The color of the wire is bright red and forms an alloy metal droplet; (7) the alloy metal droplet is heated by the plasma ring of the plasma heating jet unit 205 and blown away by the high-speed cyclone, and becomes a smaller droplet to form an atomized powder. The droplets of alloy metal that are blown off can be cooled by airflow and gravity settling due to The plasma heating jet unit 205 has a large amount of argon gas introduced, the argon gas stream brings the settled powder to the bottom of the atomizing tower 203; and (8) collects spherical particles in the powder collecting unit 206, and the particle size range It is 50 μm - 70 μm. In the present invention, increasing the frequency and power used by the high-frequency induction heating unit 204 will accelerate the melting speed of the wire, and Table 1 is part of the experimental data: <TABLE border="1"borderColor="#000000"width="85%"><TBODY><tr><td> Frequency (kHz) </td><td> Power (kW) </td><td> Wire melting time</td></tr><tr><td > 75 </td><td> 7 </td><td> 5sec </td></tr><tr><td> 400 </td><td> 18 </td><td> 2.37sec </td></tr><tr><td> 400 </td><td> 27 </td><td><1sec</td></tr></TBODY></TABLE> Table 1 Increasing the inlet pressure of the cyclone system 2053 blown into the inert gas by the plasma heating spray unit 205 helps to increase the occupancy of the powder below 63 μm. Table 2 shows some experimental data: <TABLE border="1" borderColor= "#000000"width="85%"><TBODY><tr><td> Inlet pressure (psi) </td><td> Less than 63μm powder occupancy (%) </td></tr><Tr><td> 140 </td><td> 28 </td></tr><tr><td> 180 </td><td> 36 </td></tr><tr><td > 220 </td><td> 60 </td></tr></TBODY></TABLE> Table 2 Table 3 compares the powder manufacturing apparatus of the present invention with the conventional electrode induction smelting gas atomization (EIGA) ) device and The plasma torch device produces particle size. Under similar operating conditions, the powder manufacturing apparatus and method of the present invention can effectively increase the occupancy of powders of less than 63 μm: <TABLE border="1"borderColor="#000000"width="85%"><TBODY><tr><td>device</td><td> less than 63μm powder occupancy (%) </td></tr><tr><td> EIGA device</td><Td> 33 </td></tr><tr><td> plasma torch device</td><td> 50 </td></tr><tr><td> device of the invention</td ><td> 64 </td></tr></TBODY></TABLE> Table 3 Figure 4 shows a schematic view of another apparatus 400 for making a powder material of the present invention. The feed system 401 continuously supplies the feedstock 402 to the atomization tower 403 at a steady rate. The high frequency induction heating unit 404 and the plasma heating jet unit 405 are disposed in the atomization tower 403, wherein the high frequency induction heating unit 404 heats one end of the raw material 402 to melt it into material droplets, and the feeding system 401 continuously advances the raw material. 402. The plasma heating spray unit 405 comprises a plurality of plasma heating spray guns surrounding the molten material droplets. Each of the plasma heating spray guns comprises a cathode 4051, an anode 4052 and a cyclone system 4053, and the cyclone system 4053 is formed. The plasma inert gas continuously heats the material droplets and strikes the surface of the material droplets at a high speed to heat the material droplets again to reduce the viscosity coefficient of the material itself, so that the material droplets are atomized and blown into Small droplets. Finally, the atomized droplets of material leave the heating range of the heating jet unit 405 and then gradually cool, and are coagulated and solidified by the cohesive force of the droplets of the fine material to form a powder, which naturally settles in the powder collecting unit 406. The construction and configuration of the structures and methods as shown in the various exemplary embodiments are merely illustrative. Accordingly, all such modifications are intended to be included within the scope of the present invention. The order or sequence of any program or method steps may be changed or re-sequenced according to alternative embodiments. Other substitutions, modifications, changes and omissions may be made in the design, operation, and configuration of the example embodiments without departing from the scope of the invention.

100‧‧‧Preferred electrode induction smelting gas atomization device

101‧‧‧Induction coil

102‧‧‧High pressure jet

200‧‧‧Device for the manufacture of material powders

201‧‧‧Feeding system

202‧‧‧Materials

203‧‧‧Atomization Tower

204‧‧‧High frequency induction heating unit

205‧‧‧Plastic heating jet unit

206‧‧‧Powder collection unit

207‧‧‧air inlet

2051‧‧‧ cathode

2052‧‧‧Anode

2053‧‧‧Cyclone system

1 is a schematic view of a device for manufacturing a material powder; FIG. 2 is a schematic view of a device for manufacturing a material powder according to the present invention; FIG. 3 is a schematic view of a plasma heating spray system according to the present invention; A schematic representation of a device for making a powder of material.

Claims (19)

An apparatus for manufacturing a material powder, comprising: a feeding unit for continuously supplying a raw material; and an atomizing tower, wherein the atomizing tower is provided with: a high frequency induction heating unit that heats one end of the raw material And melting it into droplets of material; a plasma heating jet unit that provides a high temperature to the droplet of material and blowing the droplet of material to atomize the droplet of material, wherein the plasma heats the jet unit It is configured to be annular and surrounds the molten droplets of the material; and a powder collection unit for collecting the material powder formed by the natural sedimentation of the atomized material droplets. A device for producing a material powder according to claim 1, wherein the raw material is a metal or a ceramic. A device for producing a material powder according to claim 1, wherein the atomization tower further comprises an air inlet to input an inert gas. The apparatus of claim 3, wherein the inert gas comprises at least one of the group consisting of argon, helium, and nitrogen. The apparatus for producing a material powder according to claim 3, wherein the plasma heating jet flow unit comprises a cyclone system to cause the inert gas to strike the material droplet at a high speed. A device for producing a material powder according to claim 1, wherein the plasma heating jet flow unit is introduced into the inert gas at a high pressure and forms a plasma. The apparatus for producing a material powder according to claim 1, wherein the plasma heating jet flow unit comprises a cathode, an anode and at least one cyclone system, wherein the cyclone system is configured to supply a plasma inert gas at a high speed. The apparatus for producing the material powder 3, wherein the high-frequency induction heating unit, the flow rate of the inert gas to 100L / m-500L / m, and a pressure of 10kg / m ² -20kg / m ² request entries. The apparatus of claim 7, wherein the cathode and the anode form a plasma ring having a power ranging from 40 kW to 100 kW. A method for producing a material powder, comprising: continuously supplying a raw material to an atomization tower at a steady rate; in the atomization tower, heating one end of the raw material and melting it into a material droplet; The droplets are surrounded by a high temperature, and the droplets of the material are sprayed to atomize the droplets of the material; and the droplets of the atomized material are naturally settled to form a powder of material. A method of producing a material powder according to claim 10, wherein the material droplet is a metal or a ceramic. The method of producing a material powder of claim 10, further comprising introducing an inert gas into the atomization tower via an air inlet. A method of making a material powder of claim 12, wherein the inert gas comprises at least one of the group consisting of argon, helium, and nitrogen. A method of producing a material powder according to claim 10, wherein the raw material is heated by a high frequency induction at a frequency of 150 kHz to 1000 kHz. A method of producing a material powder according to claim 10, wherein the raw material is heated by an induction coil having a power of 27 kW to 100 kW. The method of producing the material powder requested item 12, wherein the feed flow rate of the inert gas in the system is the 100L / m-500L / m, and a pressure of 10kg / m ² -20kg / m ² of the heating conditions. A method of producing a material powder according to claim 10, wherein the material droplets are atomized in a power of 40 kW to 100 kW. A method of producing a material powder according to claim 10, wherein the obtained powder has an average particle size The diameter is from 50 μm to 100 μm. A method of producing a material powder according to claim 10, wherein the powder having a particle diameter of more than 150 μm has a powder occupation ratio of less than 10%.