Powder preparation device, powder preparation method, and powder

Abstract

The embodiment of the invention provides a powder preparation device, a powder preparation method and powder. The powder preparation device comprises: a reaction chamber; the plasma generating device is used for forming plasma; and the crushing assembly is arranged in the reaction cavity and is used for crushing the raw materials subjected to plasma melting to form smaller powder. By adopting the powder preparation device disclosed by the embodiment of the invention, the powder with the particle size smaller than that of the raw material powder can be prepared.

Description

Technical Field

[0001] The present disclosure relates to the field of powder preparation, and in particular to a powder preparation device, a powder preparation method, and powder. Background Art

[0002] Powders such as metal powders and ceramic powders are widely used in the fields of automobiles, machinery, electronics, 3D printing, semiconductors, etc. According to the requirements of powder applications, powders that meet specific properties, such as morphology, purity, oxygen content, particle size, etc., need to be prepared.

[0003] Plasma can be used as a technical means to prepare powders. For conventional processes or devices that use plasma to prepare powders, plasma helps to transform the morphology of the powders and improve their purity. However, when small-particle powders need to be prepared, conventional preparation processes or devices cannot meet the requirements.

[0004] Therefore, it is necessary to develop a new powder preparation device and a powder preparation method. Summary of the invention

[0005] In order to solve the problem that conventional powder preparation processes or devices are difficult to prepare small-particle powders, an embodiment of the present disclosure provides a powder preparation device, which includes: a reaction chamber; a plasma generating device for forming plasma; and a crushing component, which is arranged in the reaction chamber and is used to crush the raw materials melted by plasma to form smaller powders.

[0006] In some embodiments, the fragmentation assembly includes: a rotating disk, adapted to rotate, and disposed facing the plasma.

[0007] In some embodiments, the surface of the rotating disk close to the plasma is a non-planar surface.

[0008] In some embodiments, a surface of the rotating disk close to the plasma is provided with a plurality of protrusion structures.

[0009] In some embodiments, the protruding structure is an arc-shaped rib.

[0010] In some embodiments, the protrusion structure protrudes from the surface of the rotating disk by a size of 5 mm to 10 mm.

[0011] In some embodiments, the crushing assembly further comprises: a heating assembly for heating the rotating disk.

[0012] In some embodiments, the heating element is disposed on the outer side of the rotating disk.

[0013] In some embodiments, the heating assembly includes a metal ring disposed around the rotating disk and in contact with the rotating disk.

[0014] In some embodiments, the metal ring and the rotating disk are an integral structure.

[0015] In some embodiments, the powder preparation device further includes: a collecting component for collecting powder.

[0016] An embodiment of the present disclosure also provides a method for preparing powder, which uses any of the above powder preparation devices to prepare powder, and the preparation method includes: introducing a working gas into the plasma generating device; ionizing the working gas to generate plasma; adding a first powder to be processed into the reaction chamber, forming molten droplets after passing through the plasma, and the molten droplets collide with the crushing component during the descent process to form a second powder, and the diameter of the second powder is smaller than the diameter of the first powder.

[0017] In some embodiments, the fragmentation assembly includes a rotating disk that is disposed facing the plasma and is suitable for rotating, and a rotation speed of the rotating disk is related to a density of the first powder.

[0018] In some embodiments, the rotation speed of the rotating disk is 15000 rpm / min to 50000 rpm / min.

[0019] In some embodiments, the distance between the rotating disk and one end of the plasma close to the rotating disk is 10 cm to 50 cm.

[0020] In some embodiments, the rotating disk is heated by a heating assembly to maintain a temperature of 1000° C. to 1500° C.

[0021] In some embodiments, the working gas includes: a first gas, a second gas and hydrogen; the step of introducing the working gas into the plasma generating device and ionizing the working gas to generate plasma further includes: introducing the first gas at a flow rate of 30L / min to 80L / min, introducing the second gas at a flow rate of 80L / min to 200L / min, and starting plasma discharge to generate plasma; adding hydrogen to the second gas at a flow rate of 5L / min to 20L / min and introducing it into the reaction chamber, and adjusting the plasma discharge power to 50kW to 200kW.

[0022] In some embodiments, after the plasma is generated, the pressure in the reaction chamber is controlled to be 90 kPa to 110 kPa.

[0023] In some embodiments, the first powder includes one or more of metal powder or ceramic powder.

[0024] In some embodiments, the first powder is one or more of tungsten powder, molybdenum powder, tantalum powder, niobium powder, and rhenium powder.

[0025] In some embodiments, the particle size of the first powder is 15 μm to 300 μm.

[0026] In some embodiments, the particle size D90 of the second powder is less than 5 μm, and D50 is less than 3 μm.

[0027] An embodiment of the present disclosure further provides a powder, which is prepared by any of the above powder preparation methods, wherein the particle size D90 of the powder is less than 5 μm, and D50 is less than 3 μm.

[0028] In some embodiments, the powder is molybdenum powder or tungsten powder.

[0029] Compared with the prior art, the technical solution of the embodiment of the present disclosure has the following beneficial effects:

[0030] The crushing component of the embodiment of the present disclosure collides with the raw material melted by plasma to crush it into smaller powders during the powder preparation process, thereby preparing powders with a smaller particle size than the raw material powder to meet the requirements for the powder particle size.

[0031] Furthermore, the crushing assembly of the embodiment of the present disclosure includes a rotating disk arranged facing the plasma, so that the molten droplets passing through the plasma collide with the rotating disk in a rotating state and are crushed, thereby being refined into powder with a smaller particle size.

[0032] Furthermore, the crushing component of the embodiment of the present disclosure includes a heating component, which is used to heat the rotating disk to maintain a certain temperature, so that the powder is in thermal contact with the rotating disk, avoiding the solidification of molten droplets on the surface of the rotating disk, thereby avoiding a reduction in crushing efficiency and powder preparation efficiency.

[0033] The method for preparing powder of the embodiment of the present disclosure adopts a powder preparation device including the crushing component to prepare powder. The first powder to be processed is heated by plasma to form molten droplets. The molten droplets collide with the crushing component during the descent process to form a second powder with a smaller particle size, thereby achieving powder refinement.

[0034] The powder of the embodiment of the present disclosure is prepared by the preparation method of the embodiment of the present disclosure. The particle size D90 of the powder is less than 5 μm, and D50 is less than 3 μm, which can meet the application requirements for ultrafine particle size powder. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Other features and advantages of the present disclosure will be better understood through the following detailed description of the optional embodiments in conjunction with the accompanying drawings, in which the same reference numerals represent the same or similar components, wherein:

[0036] Figure 1 A schematic structural diagram of a powder preparation device according to an embodiment of the present disclosure is shown;

[0037] Figure 2 A schematic diagram of the top view of the rotating disk of the crushing assembly according to an embodiment of the present disclosure is shown;

[0038] Figure 3-4 A schematic structural diagram of a crushing assembly according to an embodiment of the present disclosure is shown. DETAILED DESCRIPTION

[0039] Embodiments of the present disclosure are described in detail below, and examples of the embodiments are shown in the accompanying drawings. In the accompanying drawings, the same or similar reference numerals represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present disclosure, and cannot be understood as limiting the present disclosure.

[0040] Unless otherwise defined, the technical terms or scientific terms used herein shall have the usual meanings understood by persons with ordinary skills in the field to which the present disclosure belongs. In the description of the present disclosure, it should be understood that the terms "center", "longitudinal", "lateral", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present disclosure and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation to the present disclosure.

[0041] In order to solve the problem that conventional powder preparation devices cannot prepare small-particle powders, an embodiment of the present disclosure provides a powder preparation device, which includes: a reaction chamber; a plasma generating device for forming plasma; and a crushing component, which is arranged in the reaction chamber and is used to crush the raw materials melted by plasma to form powders with smaller particle sizes.

[0042] The powder preparation device according to the embodiment of the present disclosure is described in detail below with reference to the accompanying drawings.

[0043] Figure 1 FIG. 1 is a schematic diagram showing the structure of a powder preparation device according to an embodiment of the present disclosure. Figure 1The powder preparation device of the embodiment of the present disclosure includes: a reaction chamber 1, which is used to provide space and conditions for powder preparation; a plasma generating device 2, which is used to form plasma 21; and a crushing component 3, which is arranged in the reaction chamber 1 and is used to crush the raw material melted by the plasma 21 to form smaller powders.

[0044] In some embodiments, the plasma generating device 2 includes a plasma chamber 22 , which is connected to the reaction chamber 1 so that the plasma 21 and the powder can enter the reaction chamber 1 .

[0045] The first powder 4 is suitable for being fed into the plasma 21, and forms molten droplets 6 after passing through the plasma 21. The molten droplets 6 fall and collide with the crushing components to be crushed into smaller molten droplets. The smaller molten droplets solidify to form second powders 5, so that powders with smaller particle sizes can be obtained.

[0046] In some embodiments, the breaking assembly 3 includes: a rotating disk 31, which is arranged facing the plasma 21, that is, arranged on the conveying path of the molten droplets 6 to collide with it. The rotating disk 31 is suitable for rotating around its axis to increase the collision force with the molten droplets 6 and better break the molten droplets 6.

[0047] In order to improve the collision efficiency and the crushing effect, the surface of the rotating disk 31 close to the plasma 21 is a non-flat surface. Compared with the flat surface, the non-flat surface has a larger surface area, which increases the collision probability between the rotating disk 31 and the molten droplets 6 and improves the crushing efficiency.

[0048] In some embodiments, the surface of the rotating disk 31 close to the plasma 21 is provided with a plurality of protrusion structures, and the protrusion structures can be set and can include different protrusion structures at the same time. In some embodiments, the protrusion structures are arc-shaped ribs.

[0049] Figure 2 FIG. 1 is a schematic diagram showing a top view of a rotating disk of a crushing assembly according to an embodiment of the present disclosure. Figure 2 , a surface of the rotating disk 31 close to the plasma 21 is provided with a plurality of arc-shaped ribs 32, and the plurality of arc-shaped ribs 32 are evenly spaced and distributed on the surface of the rotating disk 31. In some embodiments, the rotating disk 31 is adapted to rotate about direction A, i.e., counterclockwise in a top view, and the rotation direction A is opposite to the direction extending from the concave side to the convex side of the arc-shaped rib 32. Due to the arc bending direction, the concave side of the rotating arc-shaped rib 32 has a larger contact area with the molten droplet 6 than the convex side, thereby making the probability of collision between the molten droplet 6 and the concave side of the arc-shaped rib 32 greater, which is more conducive to breaking the molten droplet 6.

[0050] In some embodiments, the protrusion structure protrudes from the surface of the rotating disk 31 by a size of 5 mm to 10 mm, thereby achieving a better crushing effect and crushing efficiency for the molten droplets 6 .

[0051] In some embodiments, the crushing assembly 3 further includes: a heating assembly 33, which is used to heat the rotating disk 31. The rotating disk 31 heated to a certain temperature can prevent the molten droplets 6 that collide with it from solidifying too quickly and affecting the crushing effect. In some embodiments, the adding assembly 33 is arranged on the outside of the rotating disk 31; in some embodiments, the heating assembly 33 is arranged on the side of the rotating disk 31 away from the plasma generating device 2.

[0052] Figure 3-4 The schematic diagram of the structure of the crushing assembly according to the embodiment of the present disclosure is shown, wherein Figure 3 A side view of the crushing assembly. Figure 4 This is a top view of the crushing assembly. Figure 3 and Figure 4 The heating component 33 is annular in structure and is arranged on the outer side of the rotating disk 31 around the rotating disk 31. In some embodiments, the heating component 33 with an annular structure is an integral structure with the rotating disk 31 or is suitable for rotating together. The heating component 33 makes the crushing range of the crushing component 3 larger, and while the annular heating component 33 heats the rotating disk 31, the molten droplets 6 that contact and collide with it remain in a molten state and are crushed due to its own temperature.

[0053] In some embodiments, the crushing component 3 is arranged directly opposite to the plasma 31. Most of the molten droplets 6 passing through the plasma 21 flow to the middle of the rotating disk 31, and a small part flows to the edge of the rotating disk 31. The temperature of the molten droplets 6 flowing to the edge of the rotating disk 31 drops relatively quickly. Therefore, the heating component 33 arranged on the outside of the rotating disk 31 helps to ensure that the molten droplets 6 colliding with the edge of the rotating disk 31 and the heating component 33 are in a molten state, so as to ensure the crushing effect and the uniformity of the crushing, and prevent the particle size distribution of the powder 7 formed after the crushing from being too wide.

[0054] In some embodiments, the ring-shaped heating component 33 is a metal ring, and the temperature of the metal ring is increased by resistive heating.

[0055] In some embodiments, arc-shaped protruding ribs 32 are protruding from the surfaces of the rotating disk 31 and the annular structure heating component 33 .

[0056] In some embodiments, the crushing assembly 3 further includes a rotating shaft 34 for driving the rotating disk 31 to rotate. The rotating shaft 34 can be connected to a motor, and the motor provides power for the rotation of the rotating shaft 34.

[0057] In some embodiments, a temperature sensor is provided on the rotating disk 31 to detect its temperature.

[0058] In the powder preparation device of the disclosed embodiment, in some embodiments, the position of the crushing assembly 3 in the reaction chamber 1 can be adjusted, so as to adjust the distance between the crushing assembly 3 and the plasma 21 to adapt to plasmas 21 of different sizes and energy distributions. In some embodiments, the powder preparation device further includes a position adjustment device for adjusting the distance between the crushing assembly 3 and the plasma 21 to avoid the crushing assembly 3 and the plasma 21 being too far away from each other, causing the molten droplets 6 to solidify, to avoid the distance being too close, causing the rotating disk 31 to be unable to withstand the high temperature of the plasma 21, or to avoid the distance being too close, causing the molten droplets 6 to be insufficiently melted, that is, to collide with the rotating disk 31 and affect the crushing effect. In some embodiments, the distance between the rotating disk 31 of the crushing assembly 3 and one end of the plasma 21 close to it is adjusted to be 10 cm to 50 cm.

[0059] The powder preparation device of the embodiment of the present disclosure, the plasma generating device 2 can have multiple implementations to generate plasma with specific energy density and other properties according to the requirements of the powder preparation process for the plasma to be generated.

[0060] In some embodiments, the plasma generating device 2 further includes an induction coil 23, which is connected to a power source 24. When powered on, an electromagnetic field is generated to ionize the working gas introduced into the plasma chamber 22, thereby generating plasma 21. In some embodiments, the power source 24 is a high-frequency power source, which provides a high-frequency current to the induction coil 23. In some embodiments, the induction coil 23 is disposed around the plasma chamber 22, which is conducive to generating high-energy plasma in the plasma chamber 22.

[0061] In some embodiments, the plasma chamber 22 includes a first chamber wall 221, and the working gas ionized to generate plasma is introduced into the plasma chamber 22 from the first chamber wall 221; in some embodiments, the first chamber wall 221 is provided with a plurality of gas inlets (not shown in the figure), which are used to respectively introduce working gases with different flow rates or different functions, for example, the first chamber wall 221 is provided with a first gas inlet and a second gas inlet, wherein the first gas inlet is used to introduce the first gas, and the second gas inlet is used to introduce the second gas; the first gas can be argon, and the second gas can be argon, or a mixed gas of argon and hydrogen. In some embodiments, more gas inlets can be provided to simultaneously introduce different gas flow rates to adjust the ratio of each gas, so as to facilitate adjusting the energy density of the generated plasma.

[0062] In some embodiments, a raw material inlet pipe 222 is further provided on the first chamber wall 221 of the plasma chamber 22, so that the raw material first powder 4 for preparing the second powder 5 is fed into the plasma chamber 22 through the raw material inlet pipe 222. In some embodiments, the raw material inlet pipe 222 is provided above the plasma 21, so that the first powder 4 is fed into the plasma 21.

[0063] The temperatures of different regions of the plasma 21 are different, and thus the first powder 4 can be transported into different temperature regions of the plasma 21 according to the melting point and melting degree requirements of the first powder 4 .

[0064] In some embodiments, according to the melting point and melting degree requirements of the first powder 4, the raw material inlet pipe 222 is set at a corresponding position in a specific temperature zone of the plasma 21, which is conducive to more efficiently and fully making the first powder 4 reach a molten state, or even reach completely molten droplets, thereby helping to improve the crushing efficiency of the crushing component 3.

[0065] In some embodiments, the first powder 4 is delivered into the plasma 21 via a carrier gas to improve the delivery efficiency and accuracy of the first powder 4 , thereby improving the melting efficiency of the first powder 4 .

[0066] refer to Figure 1 In some embodiments, a vacuum pipeline 11 is provided on a cavity wall of the reaction chamber 1 of the powder preparation device, and the vacuum pipeline 11 is connected to the vacuum system. The working gas and the carrier gas continuously enter the reaction chamber 1, and the gas is exhausted from the vacuum pipeline 11 by the vacuum system to control the pressure of the reaction chamber 1. When the powder preparation device is about to start the powder preparation process, the air in the reaction chamber 1 is exhausted through the vacuum system, especially the oxygen and other gases that have an impact on the plasma treatment process, and a lower vacuum degree is reached; when the powder preparation process is completed, the gas in the reaction chamber 1 is exhausted through the vacuum system and replaced with clean air.

[0067] Continue to refer Figure 1 In some embodiments, the powder preparation device of the embodiment of the present disclosure further includes a collecting component 7 for collecting the second powder 5; the collecting component 7 is connected to the reaction chamber 1 so that the second powder 5 enters the reaction chamber 1. The collecting component 7 and the plasma generating device 2 can be arranged on opposite sides of the reaction chamber 1.

[0068] By using the powder preparation device of the embodiment of the present disclosure, a second powder 5 with a smaller particle size is prepared using the first powder 4 as raw material. The first powder 4 is melted by the plasma 21, and the molten droplets 6 collide with the crushing component 3 and are crushed into smaller molten droplets, which then solidify to form the second powder 5.

[0069] For first powders 4 of different densities, the crushing efficiency and crushing effect are ensured by adjusting the rotation speed of the rotating disk 31 of the crushing assembly 3. In some embodiments, the rotation speed of the rotating disk 31 is 15000 rpm / min to 50000 rpm / min.

[0070] In some embodiments, the rotation speed of the rotating disk 31 is automatically adjusted according to the temperature, length and width of the plasma 21, and the distance between the rotating disk and the plasma 21, so that efficient and continuous powder preparation can still be achieved when the properties of the plasma 21 change.

[0071] In some embodiments, the second powder 5 prepared by the powder preparation device of the embodiment of the present disclosure has a particle size D90 of less than 5 μm, a D50 of less than 3 μm, and a concentrated particle size distribution.

[0072] The second powder is prepared using the powder preparation device of the embodiment of the present disclosure. Since the plasma 21 has a spheroidizing effect on the morphology of the powder, the second powder 5 is a spherical powder with a small particle size and a concentrated particle size distribution. It has good fluidity and packing density and can be used in 3D printing, target material production, preparation of ceramic slurry and other fields.

[0073] In some embodiments, the second powder 5 is a refractory metal powder or ceramic powder such as tungsten, molybdenum, tantalum, niobium, and rhenium. In some embodiments, the second powder 5 is molybdenum powder or tungsten powder, which is used to prepare an electronic paste for HTCC high temperature co-fired ceramics. The electronic paste is stable at high temperatures and forms a good bond with other materials such as a ceramic substrate during the sintering process. It has high printing resolution, one-time firing, controllable dielectric layer thickness, smooth surface, unlimited number of stacking layers, and matches the thermal expansion coefficient of silicon semiconductors, and has good performance and processing efficiency.

[0074] The embodiments of the present disclosure also provide a method for preparing powder, which uses the powder preparation device of any of the above embodiments to prepare powder.

[0075] In some embodiments, the preparation method includes: introducing a working gas into a plasma generating device; ionizing the working gas to generate plasma; adding a first powder to be processed into a reaction chamber, melting after passing through the plasma to form molten droplets, and the molten droplets collide with the crushing component during the descent process to form a second powder, and the diameter of the second powder is smaller than the diameter of the first powder.

[0076] In some embodiments, the crushing assembly includes a rotating disk disposed facing the plasma, and the rotating disk is rotated to collide and crush the molten droplets formed after passing through the plasma to form smaller powders. The crushing assembly and the rotating disk are the same as in any of the above embodiments and will not be repeated here.

[0077] The rotation speed of the rotating disk is related to the density of the first powder. The smaller the density of the first powder, the higher the rotation speed of the rotating disk is required to ensure the crushing effect. In some embodiments, the rotation speed of the rotating disk is 15000rpm / min to 50000rpm / min; in some embodiments, the rotation speed of the rotating disk is 20000rpm / min to 50000rpm / min; in some embodiments, the rotation speed of the rotating disk is 30000rpm / min to 50000rpm / min.

[0078] In some embodiments, the rotation speed of the rotating disk is automatically adjusted according to the temperature and range (length and width) of the plasma, and the distance between the rotating disk and the end of the plasma closest to it, so that efficient and continuous powder preparation can be achieved when the properties of the plasma change.

[0079] In some embodiments, the distance between the crushing assembly and the plasma is adjusted to prevent the crushing assembly from being too far away from the plasma, causing the molten droplets to solidify before being crushed, and to prevent the rotating disk 31 from being too close to withstand the high temperature of the plasma 21, or the molten droplets 6 from being insufficiently melted and colliding with the rotating disk 31, thereby affecting the crushing effect. In some embodiments, the distance between the rotating disk of the crushing assembly and one end of the plasma close to it is adjusted to be 10 cm to 50 cm.

[0080] In some embodiments, the preparation method further includes: heating the rotating disk; the rotating disk heated to a certain temperature can prevent the molten droplets colliding with it from solidifying too quickly and affecting the crushing effect. The temperature at which the rotating disk needs to be heated and maintained can be set accordingly according to the melting point of the first powder 4. The higher the melting point of the first powder 4, the higher the temperature maintained by the rotating disk. In some embodiments, the rotating disk is heated to maintain its temperature at 1000°C to 1500°C; in some embodiments, the rotating disk is heated by a heating component.

[0081] In some embodiments, the working gas introduced into the plasma chamber includes an inert gas; in some embodiments, the working gas is an inert gas and hydrogen, and the inert gas can be one or more of helium, neon, and argon.

[0082] The preparation method of the disclosed embodiment adjusts the energy of the plasma generated by the ionization of the working gas by controlling the type and flow rate of the working gas. In some embodiments, the introduced working gas includes a first gas and a second gas, the first gas is an inert gas, and is introduced into the reaction chamber at a flow rate of 30L / min to 80L / min; the second gas is an inert gas, and is introduced into the reaction chamber at a flow rate of 80L / min to 200L / min. In some embodiments, the working gas also includes hydrogen. After the plasma is formed, the hydrogen and the second gas are introduced into the reaction chamber together, and the flow rate of the hydrogen is 5L / min to 20L / min.

[0083] In some embodiments, ionizing the working gas to generate plasma includes: turning on a power source to generate an electric field or an electromagnetic field in the plasma chamber, so that the working gas introduced into the plasma chamber is ionized to generate plasma.

[0084] In some embodiments, after the plasma is formed, the discharge power is adjusted to 50 kW to 200 kW to ensure that the plasma is at a relatively stable energy level. In some embodiments, after the plasma is formed, the pressure in the reaction chamber is controlled to 90 kPa to 110 kPa to ensure that the plasma is at a relatively stable energy level.

[0085] In some embodiments, the first powder is introduced into the plasma chamber through a carrier gas, and the carrier gas is an inert gas. In some embodiments, the first powder is introduced into the plasma at a flow rate of 10 g / min to 150 g / min under the action of a carrier gas at a flow rate of 5 L / min to 20 L / min, and in some embodiments, the first powder is introduced into the region with the highest energy of the plasma.

[0086] The powder preparation method of the embodiment of the present disclosure is adopted, and the first powder is used as a raw material to prepare the second powder. In some embodiments, the particle size of the first powder is 15μm to 300μm, and the particle size D90 of the second powder is less than 5μm, and D50 is less than 3μm. The preparation method of the embodiment of the present disclosure can be used to prepare powders with smaller particle sizes.

[0087] In the method for preparing the powder of the disclosed embodiment, since plasma has a spheroidizing effect on the morphology of the powder, the second powder is a spherical powder with a small particle size and a concentrated particle size distribution, has good fluidity and packing density, and can be used in 3D printing, target material production, preparation of ceramic slurry and other fields.

[0088] The method for preparing the powder of the embodiment of the present disclosure can be applied to prepare a second powder with a smaller particle size using a plurality of metal or ceramic powders as the first powder. In some embodiments, the first powder includes one or more of metal powder or ceramic powder; in some embodiments, the first powder is one or more of tungsten powder, molybdenum powder, tantalum powder, niobium powder, rhenium powder, refractory metal powder or ceramic powder; in some embodiments, the first powder is molybdenum powder or tungsten powder, and a second powder with a particle size D90 less than 5μm and D50 less than 3μm is prepared, and the second powder is also molybdenum powder or tungsten powder, which is used to prepare the electronic paste of HTCC high temperature co-fired ceramics, the electronic paste has stability at high temperature, and forms a good combination with other materials such as ceramic substrates during the sintering process, has high printing resolution, one-time firing, controllable dielectric layer thickness, smooth surface, unlimited number of stacking layers, matches the thermal expansion coefficient of silicon semiconductor, and has good performance and processing efficiency.

[0089] In a specific embodiment, the powder preparation method of the present disclosure includes:

[0090] Start the vacuum system and evacuate the reaction chamber to a vacuum degree no greater than 0.1 Pa;

[0091] At different positions on the cavity wall of the reaction cavity, a first gas argon gas is introduced into the plasma cavity at a flow rate of 50 L / min and a second gas argon gas is introduced at a flow rate of 130 L / min, and a power supply is turned on to generate a plasma flame in the plasma cavity, with a portion of the plasma flame located in the reaction cavity; hydrogen gas is introduced into the second gas at a flow rate of 15 L / min, and the plasma discharge power is adjusted to 100 kW to keep the plasma flame in a stable state;

[0092] Start the crushing assembly, make the rotating disk rotate at a speed of 40000rpm / min, and heat the rotating disk through the heating assembly to a temperature of 1500℃;

[0093] The pressure in the reaction chamber is controlled to be 100 kPa by a vacuum system, and the first powder (particle size is 15 μm to 53 μm) is transported to the plasma flame at a powder supply rate of 80 g / min and an argon carrier gas of 10 L / min. The first powder is heated to become molten droplets, which collide with the rotating disk under the action of the carrier gas and are broken, and solidify to form the second powder;

[0094] Stop introducing the carrier gas and the first powder, close the crushing assembly, turn off the power supply, stop introducing the first gas, the second gas and hydrogen, close the vacuum system, and obtain the second powder in the collecting device. The particle size of the second powder is D90=4.5μm and D50=2.5μm.

[0095] The embodiment of the present disclosure further provides a powder, which is prepared by the powder preparation method of the embodiment of the present disclosure, and the particle size D90 of the powder is less than 5 μm, and D50 is less than 3 μm.

[0096] In some embodiments, the powder is molybdenum powder or tungsten powder with a particle size D90 less than 5 μm and D50 less than 3 μm, and is used to prepare an electronic paste for HTCC high-temperature co-fired ceramics. The electronic paste is stable at high temperatures and forms a good bond with other materials such as a ceramic substrate during the sintering process. It has high printing resolution, one-time firing, controllable dielectric layer thickness, smooth surface, unlimited number of stacking layers, matches the thermal expansion coefficient of silicon semiconductors, and has good performance and processing efficiency.

[0097] Since the plasma treatment has a spheroidizing effect on the morphology of the first powder, the second powder is a spherical powder with a smaller particle size and a concentrated particle size distribution. It has good fluidity and packing density, and can meet the application requirements for ultrafine particle size powders. For example, it can be used in 3D printing, target material production, preparation of ceramic slurry and other fields.

[0098] The above is only an exemplary embodiment used to illustrate the principle of the present disclosure, and is not intended to limit the scope of protection of the present disclosure. For those of ordinary skill in the art, various modifications and improvements can be made without departing from the spirit and essence of the present disclosure, and these modifications and improvements are also within the scope of protection of the present disclosure.

Claims

1. A powder preparation device, characterized in that: include: Reaction chamber; A plasma generating device for forming plasma; The crushing assembly is arranged in the reaction chamber and is used for crushing the plasma-melted raw materials to form smaller powders.

2. The powder preparation device according to claim 1, characterized in that: The fragmentation assembly includes a rotating disk, which is suitable for rotating and disposed facing the plasma.

3. The powder preparation device according to claim 2, characterized in that: The surface of the rotating disk close to the plasma is a non-planar surface.

4. The powder preparation device according to claim 3, characterized in that: A surface of the rotating disk close to the plasma is provided with a plurality of protruding structures.

5. The powder preparation device according to claim 4, characterized in that: The protruding structure is an arc-shaped rib.

6. The powder preparation device according to claim 4, characterized in that: The protrusion structure protrudes from the surface of the rotating disk by a size of 5 mm to 10 mm.

7. The powder preparation device according to claim 2, characterized in that: The crushing assembly further comprises: a heating assembly for heating the rotating disk.

8. The powder preparation device according to claim 7, characterized in that: The heating component is arranged on the outer side of the rotating disk.

9. The powder preparation device according to claim 8, characterized in that: The heating assembly includes a metal ring disposed around the rotating disk and in contact with the rotating disk.

10. The powder preparation device according to claim 9, characterized in that: The metal ring and the rotating disk are an integrated structure.

11. The powder preparation device according to any one of claims 1 to 10, characterized in that: Also includes: The collecting component is used to collect powder.

12. A method for preparing a powder, characterized in that: The powder is prepared by using the powder preparation device according to any one of claims 1 to 11, comprising: introducing working gas into the plasma generating device; ionizing the working gas to generate plasma; A first powder to be processed is added into the reaction chamber, and molten droplets are formed after passing through the plasma. The molten droplets collide with the crushing component during the descent process to form a second powder, and the diameter of the second powder is smaller than that of the first powder.

13. The preparation method according to claim 12, characterized in that: The fragmentation assembly includes a rotating disk that is arranged to face the plasma and is suitable for rotating. The rotation speed of the rotating disk is related to the density of the first powder.

14. The preparation method according to claim 13, characterized in that: The rotating speed of the rotating disk is 15000 rpm / min to 50000 rpm / min.

15. The preparation method according to claim 13, characterized in that: The distance between the rotating disk and one end of the plasma close to the rotating disk is 10 cm to 50 cm.

16. The preparation method according to claim 13, characterized in that: The rotating disk is heated by a heating assembly to maintain its temperature at 1000°C to 1500°C.

17. The preparation method according to claim 12, characterized in that: The working gas includes: a first gas, a second gas and hydrogen; the step of introducing the working gas into the plasma generating device and ionizing the working gas to generate plasma further includes: The first gas is introduced at a flow rate of 30 L / min to 80 L / min, the second gas is introduced at a flow rate of 80 L / min to 200 L / min, and plasma discharge is started to generate plasma; Hydrogen is added to the second gas at a flow rate of 5 L / min to 20 L / min and introduced into the reaction chamber, and the plasma discharge power is adjusted to 50 kW to 200 kW.

18. The preparation method according to claim 12, characterized in that: After the plasma is generated, the pressure in the reaction chamber is controlled to be 90 kPa to 110 kPa.

19. The preparation method according to any one of claims 12 to 18, characterized in that: The first powder includes one or more of metal powder or ceramic powder.

20. The preparation method according to claim 19, characterized in that: The first powder is one or more of tungsten powder, molybdenum powder, tantalum powder, niobium powder and rhenium powder.

21. The preparation method according to any one of claims 12 to 18, characterized in that: The particle size of the first powder is 15 μm to 300 μm.

22. The preparation method according to claim 21, characterized in that: The particle size D90 of the second powder is less than 5 μm, and D50 is less than 3 μm.

23. A powder, characterized in that: The powder is prepared by the method for preparing a powder according to any one of claims 12 to 22, wherein the particle size D90 of the powder is less than 5 μm, and D50 is less than 3 μm.

24. The powder according to claim 23, characterized in that The powder is molybdenum powder or tungsten powder.

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