CN112091229A - Device and method for refining particle size of metal powder - Google Patents

Abstract

The invention relates to a device and a method for refining the grain diameter of metal powder. The device includes: an atomization chamber; the powder feeding assembly is communicated with the atomizing chamber and is used for providing coarse-grain-size metal powder to the atomizing chamber; a heating unit provided in a communication path between the powder feeding unit and the atomizing chamber, for heating the coarse-grained metal powder to a state where the coarse-grained metal powder starts to melt before the coarse-grained metal powder is decomposed; and an inert gas supply system for decomposing the coarse-particle-size metal powder by blowing an inert gas to the heated coarse-particle-size metal powder, and for providing a protective atmosphere at the time of heating and decomposition of the coarse-particle-size metal powder. The invention can separate 1 coarse-grain-size metal powder into a plurality of fine-grain-size metal powders, so that the grain sizes of the produced metal powders are concentrated to 10-100 mu m.

Description

A device and method for refining the particle size of metal powder

technical field

The invention relates to the technical field of atomization and pulverization, in particular to a device and method for refining the particle size of metal powder.

Background technique

In recent years, with the development of powder metallurgy technologies such as hot isostatic pressing, metal additive manufacturing, and injection molding, the demand for metal powder has grown rapidly; The quality of the powder, especially the particle size distribution, puts forward higher requirements. The 3D printing technology represented by powder bed selective melting and forming has a particle size requirement of 15-100 μm for metal powder.

In the related art, the production technologies of metal powder mainly include gas atomization powder production, plasma fuse atomization powder production, and plasma rotary electrode powder production. Among them, gas atomization pulverizing uses high-pressure gas to directly act on the metal solution, and the prepared metal powder contains more hollow powders; the plasma fuse atomization pulverizing technology can only be used for atomization pulverizing of non-brittle wire materials. The type of bulk material is limited; the metal powder produced by the plasma rotating electrode powder technology has become a recognized high-quality powder preparation technology in the industry due to its high sphericity, good fluidity, and low impurity content.

Regarding the above technical solutions, the inventor found that there are at least the following technical problems: the traditional rotating electrode powder milling technology is subject to technical bottlenecks such as the limit operating speed of the equipment and the diameter of the electrode bar, and the particle size of the metal powder produced is concentrated in 20~250μm. Taking titanium alloy powder as an example, the yield of rotating electrode powder with a particle size of less than 100 μm is less than 40%, and the coarse powder particle size limits the application of rotating electrode powder technology in the field of 3D printing.

Therefore, it is necessary to improve one or more problems existing in the above-mentioned related technical solutions.

It should be noted that this section is intended to provide a background or context for the technical solutions of the invention recited in the claims. The descriptions herein are not admitted to be prior art by inclusion in this section.

SUMMARY OF THE INVENTION

The purpose of the present invention is to provide a device and method for refining the particle size of metal powder, thereby overcoming one or more problems caused by limitations and defects of the related art at least to a certain extent.

First, according to the present invention, a device for refining the particle size of metal powder is provided, comprising:

atomization chamber;

a powder feeding assembly, which is communicated with the atomizing chamber and is used for providing the coarse-grained metal powder to the atomizing chamber;

a heating assembly, which is arranged in the communication path between the powder feeding assembly and the atomizing chamber, and is used for heating the coarse-grained metal powder to the beginning before the coarse-grained metal powder is decomposed the state of melting;

an inert gas supply system, the inert gas supply system communicates with the atomizing chamber and the heating assembly, and the inert gas supply system blows inert gas to the heated coarse-grained metal powder to make the coarse-grained metal powder The metal powder decomposes and serves to provide a protective atmosphere upon heating and decomposition of the coarse-grained metal powder.

Preferably, the powder feeding assembly includes a supply end for accommodating the coarse-grained metal powder and a conveying end in communication with the supply end, a cylindrical interface is provided on the top of the atomization chamber, and the powder feeding assembly has a The delivery end communicates with the atomization chamber through the cylindrical interface.

Preferably, the top of the atomization chamber is provided with a cylindrical interface, the cylindrical interface is provided with an interlayer, and the heating component is provided in the interlayer of the cylindrical interface.

Preferably, the inert gas supply system includes an inert gas source, a low-pressure gas outlet, and a high-pressure gas outlet, the inert gas source is used to supply the inert gas to the low-pressure gas outlet and the high-pressure gas outlet, and the low-pressure gas outlet Both the end and the high-pressure gas outlet are communicated with the atomizing chamber, wherein the high-pressure gas outlet is arranged below the heating assembly.

Preferably, the height of the heating assembly ranges from 10 to 200 mm, the diameter ranges from 2 to 100 mm, and the power ranges from 1 to 1000 kW.

Preferably, the height, diameter and operating power of the heating assembly are associated with the material and particle size of the coarse-grained metal powder.

Preferably, the powder feeding speed of the powder feeding assembly ranges from 10 to 10000 g/min, and the powder feeding speed of the powder feeding assembly is related to the working power of the heating assembly.

According to the present invention, there is also provided a method for refining the particle size of metal powder, comprising the following steps:

providing a protective atmosphere through the inert gas supply system;

supplying the coarse-grained metal powder to the atomizing chamber through the powder feeding assembly;

In the protective atmosphere, the coarse-grained metal powder is heated to a state of starting to melt by the heating component before the coarse-grained metal powder is decomposed;

In the protective atmosphere, the coarse-grained metal powder is decomposed by blowing an inert gas to the heated coarse-grained metal powder through the inert gas supply system;

Here, the coarse-grained metal powder in the state of beginning to melt has an outer portion in a liquid state and an inner portion in a solid state.

Preferably, the coarse-grained metal powder is heated by the heating assembly to have an outer portion in a liquid state and an inner portion in a solid state.

Preferably, an inert gas with a pressure of 3-8 Mpa and a speed of 50-800 m/s is blown to the heated coarse-grained metal powder through an inert gas supply system, so that the liquid outer part is blown away from the solid inner part. Partial separation.

Preferably, the powder feeding speed of the powder feeding assembly and the working power of the heating assembly are adjusted for metal powders of different materials and particle sizes.

The technical scheme provided by the present invention can include the following beneficial effects:

Through the above method and device, on the one hand, one coarse-grained metal powder can be separated into a plurality of fine-grained metal powders, so that the particle size of the produced metal powders is concentrated at 10-100 μm, and can be used as a traditional rotating electrode The perfect complement of atomization powder technology; on the other hand, it has the advantages of high sphericity, good fluidity and good compressibility of metal powder, and also has the characteristics of high efficiency, good quality and good batch consistency.

Description of drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the disclosure and together with the description serve to explain the principles of the disclosure. Obviously, the drawings in the following description are only some embodiments of the present disclosure, and for those of ordinary skill in the art, other drawings can also be obtained from these drawings without creative effort.

FIG. 1 shows a schematic diagram of a device for refining the particle size of metal powder in an exemplary embodiment of the present invention;

FIG. 2 shows a schematic diagram of a process for refining coarse-grained metal powder in an exemplary embodiment of the present invention;

3 shows a schematic cross-sectional view of the coarse-grained metal powder at the beginning of melting in an exemplary embodiment of the present invention.

Reference signs: Atomization chamber-100, powder discharge port-110, powder feeding assembly-200, supply end 210, conveying end-220, heating assembly-300, vacuum system-400, inert gas supply system-500, high pressure gas outlet End-510, Low pressure outlet-520, Inert gas source-530, Pressure control assembly-600, Collection assembly-700, Coarse grain metal powder-800, Solid inner part-810, Liquid outer part-820 , Fine-grained metal powder -900.

Detailed ways

Example embodiments will now be described more fully with reference to the accompanying drawings. Example embodiments, however, can be embodied in various forms and should not be construed as limited to the examples set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the concept of example embodiments to those skilled in the art. The described features, structures, or characteristics may be combined in any suitable manner in one or more embodiments.

Furthermore, the drawings are merely schematic illustrations of embodiments of the invention and are not necessarily drawn to scale. The same reference numerals in the drawings denote the same or similar parts, and thus their repeated descriptions will be omitted. Some of the block diagrams shown in the figures are functional entities that do not necessarily necessarily correspond to physically or logically separate entities.

This example embodiment provides an apparatus for refining the particle size of metal powder. Referring to Figures 1 and 2, the apparatus may include:

The atomizing chamber 100; the powder feeding assembly 200, the powder feeding assembly 200 communicates with the atomizing chamber 100, and is used for providing the coarse-grained metal powder 800 to the atomizing chamber 100; the heating assembly 300, the heating assembly 300 is arranged between the powder feeding assembly 200 and the atomizing chamber 100 In the communication path of the atomization chamber 100, the coarse-grained metal powder 800 is heated to a state of starting to melt before the coarse-grained metal powder 800 is decomposed; the inert gas supply system 500, the inert gas supply system 500 is heated by The resulting coarse-grained metal powder 800 is blown with an inert gas to decompose the coarse-grained metal powder 800 , and serves to provide a protective atmosphere during heating and decomposition of the coarse-grained metal powder 800 .

It should be understood that the preferred particle size range of the coarse-grained metal powder 800 is 100-200 μm when it is refined, but it is not limited to this, and other particle sizes are also possible. The coarse-grained metal powder 800 is only relative For the fine-grained metal powder 900 obtained after refining.

It should be understood that, as shown in FIG. 3 , when the powder feeding component 200 transports the coarse-grained metal powder 800 into the atomization chamber 100 , the coarse-grained metal powder 800 is heated by the heating component 300 and begins to melt. , to form an outer portion 820 in a liquid state and an inner portion 810 in a solid state, after the coarse-grained metal powder 800 enters the atomization chamber 100 in this state, it is impacted by the inert gas provided by the inert gas supply system 500, and in Decomposition of the coarse-grained metal powder 800 is completed in the atomization chamber 100 , so that one coarse-grained metal powder is decomposed into a plurality of fine-grained metal powders. After the coarse-grained metal powder 800 is heated to a state where it begins to melt, it is very easy to react with other reactive gases to destroy the metal powder, so a protective atmosphere needs to be provided during the heating and decomposition of the coarse-grained metal powder 800 . Among them, the protective atmosphere refers to the gas protective environment without oxidation and decarburization. Gases such as nitrogen or argon can be selected. In order to ensure the reliability of the protective atmosphere and improve the purity of the inert gas in the protective atmosphere, it can be used before injecting the inert gas. Evacuate first, and then inject inert gas to improve the purity of the inert gas in the protective atmosphere.

The atomization chamber 100 has sealability, and the atomization chamber 100 is provided with a powder discharge port 110 for discharging the refined metal powder. The heating element 300 can be heated by an induction coil, ion arc, electric arc or electron beam. The heating method of the heating element 300 is not limited as long as the heating temperature of the coarse-grained metal powder 800 can be controlled.

Through the above device, on the one hand, one coarse-grained metal powder can be decomposed into multiple fine-grained metal powders, so that the particle size of the produced metal powders can be concentrated in 10-100 μm; on the other hand, it can be used as a traditional rotating electrode mist. The supplement of chemical powder milling technology has the advantages of high sphericity, good fluidity and good compressibility of metal powder, and has the characteristics of high efficiency, good quality and good batch consistency.

In the following, various parts of the above-described apparatus in this example embodiment will be described in more detail with reference to FIGS. 1 to 2 .

In one embodiment, referring to FIG. 1 , the powder feeding assembly 200 includes a feeding end 210 for containing the coarse-grained metal powder 800 and a feeding end 220 communicating with the feeding end 210 , and the top of the atomization chamber 100 is provided with a cylindrical shape An interface, the conveying end 220 of the powder feeding assembly communicates with the cylindrical interface. Wherein, the powder feeding component 200 can use scraper type, rotary disc pneumatic type, electromagnetic vibration type, drum type or double cylinder type to convey metal powder, as long as it can provide coarse-grained metal powder 800 to the atomizing chamber 100, and The specific conveying method of the powder feeding assembly 200 is not limited. It should be understood that the supply end 210 of the powder feeding assembly 200 may be a separate device for placing the coarse-grained metal powder 800, or may be a metal powder temporary storage device of the metal powder milling equipment, that is, the device of the present invention may Combined with other metal powder pulverizing equipment, the metal powder obtained by this equipment is refined again. In addition, the delivery end 220 is communicated with the top of the atomization chamber 100. After the coarse-grained metal powder 800 is delivered to the top of the atomization chamber 100, it can directly fall into the atomization chamber 100 by gravity for heating or decomposition. step, without the need to transport through additional devices, thereby improving efficiency and saving costs.

In one embodiment, as shown in FIG. 1 , the top of the atomization chamber 100 is provided with a cylindrical interface, and the cylindrical interface is provided with an interlayer, and the heating component 300 is provided in the interlayer of the cylindrical interface. It should be understood that the conveying end 220 of the powder feeding assembly 200 may communicate with the atomizing chamber 100 through a cylindrical interface, and the heating assembly 300 may include a cylindrical interface, that is, the heating assembly 300 may include a circular A cylindrical base and a heating element disposed in the interlayer, and the heating assembly 300 is installed on the top of the atomization chamber 100 . The heating element can be an induction coil, an ion arc, an electric arc or an electron beam. In addition, since the heating assembly 300 is disposed on the top of the atomization chamber 100, after the coarse-grained metal powder 800 is transported to the top of the atomization chamber 100, it can be directly heated in the atomization chamber, so that the coarse-grained metal powder 800 can be heated directly. Both heating and decomposition can be completed in the atomization chamber, which is more conducive to providing a protective atmosphere for the coarse-grained metal powder 800, and only needs to keep the atomization chamber sealed, which improves the simplicity of the device.

In one embodiment, as shown in FIG. 1 , the inert gas supply system 500 includes an inert gas source 530 , a low pressure gas outlet 520 and a high pressure gas outlet 510 , and the inert gas source 530 is used to supply the low pressure gas outlet 520 and the high pressure gas outlet 510 supplies inert gas, and both the low-pressure gas outlet 520 and the high-pressure gas outlet 510 communicate with the atomizing chamber 100 , wherein the high-pressure gas outlet 510 is disposed below the heating assembly 300 . Referring to FIG. 1 , preferably, the low-pressure gas outlet 520 provides a low-pressure inert protective atmosphere for the atomization chamber through the pressure control valve B, and the high-pressure gas outlet 510 is arranged below the heating assembly 300 and is provided through the pressure control valve A. A high-pressure and high-speed inert gas is used to decompose the heated coarse-grained metal powder 800 . Wherein, the high-pressure gas outlet 510 may adopt a ring-slit structure or a plurality of high-pressure nozzle coupling structures, but it is not specifically limited. In addition, the inert gas source 530 can be connected to the low pressure gas outlet 520 and the high pressure gas outlet 510 through one gas delivery channel, or can be respectively connected to the low pressure gas outlet end 520 and the high pressure gas outlet end 510 through two independent gas delivery channels.

In one embodiment, referring to FIG. 2 , the height of the heating assembly 300 ranges from 10 to 200 mm, the diameter ranges from 2 to 100 mm, and the power ranges from 1 to 1000 kW. Specifically, the height of the heating area of the heating component 300 is H=10~200mm, and the diameter D=φ2~100mm; the heating component 300 can be resistance heating, laser or radio frequency inductively coupled plasma; (600°C) to tungsten alloy (3400°C)), the diameter of the coarse-grained metal powder 800 ranges from 100 to 200 μm, and the corresponding heating element 300 has a power range of 1 to 1000kW.

Specifically, in one embodiment, referring to FIGS. 2 and 3 , the height H, diameter D and working power of the heating assembly are associated with the material and particle size of the coarse-grained metal powder 800 . When the coarse-grained metal powder 800 with a diameter of ΦD ₁ is heated to a state where it begins to melt, the diameter of the solid inner portion 810 is ΦD ₂ , and the range of the liquid outer portion 820 is ΦD ₁ -ΦD ₂ . The amount of heat Q required for the particle size metal powder 800 to be heated to the state where it begins to melt is as follows:

表达式（1）；

expression(1);

where ρ is the theoretical density of the metal powder, C _P is the specific heat of the metal powder, T _m is the melting point of the metal powder, H _m is the latent heat of fusion of the metal powder, and T ₀ is room temperature.

According to this expression, the heat required for melting a single metal powder particle has a cubic relationship with the diameter. The larger the particle size of the powder particle, the greater the energy required for melting, and it is not easy to evaporate. Metal powder heated by heating assembly 300 typically undergoes the following stages: solid phase heating, from the initial temperature to the melting point of the material, where the solid phase melts; and liquid phase heating, from the melting point of the material to near the boiling point of the material. Thus, the heat required by the coarse-grained metal powder 800 in each stage in the heating assembly 300 is calculated, and the working power of the heating assembly 300 is adjusted accordingly.

In one embodiment, the powder feeding speed of the powder feeding assembly 200 ranges from 10 to 10000 g/min, and the powder feeding speed of the powder feeding assembly 200 is associated with the working power of the heating assembly 300 . It should be understood that the amount of heat required to heat a single metal powder can be derived according to expression (1), and by adjusting the powder feeding speed of the powder feeding assembly 200, the quantity of the metal powder to be heated by the heating assembly 300 can be determined, thereby determining the heating The operating power of the assembly 300.

In one embodiment, referring to FIG. 1 , the apparatus further includes a vacuum system 400 in communication with the atomization chamber 100 for providing a vacuum environment before the inert gas supply system 500 provides a protective atmosphere. After the atomization chamber 100 is evacuated, extra gas can be effectively removed, and the inert gas is supplied to the atomization chamber 100 through the inert gas supply system 500, which can provide the purity of the inert gas in the atomization chamber 100, thereby ensuring the protective atmosphere reliability.

In one embodiment, referring to FIG. 1 , the device further includes a pressure control assembly 600 , which communicates with the atomization chamber 100 for stabilizing the pressure inside the atomization chamber 100 . When the inert gas supply system 500 blows the inert gas that decomposes the coarse-grained metal powder 800 , the pressure inside the atomization chamber 100 is increased due to excessive inert gas, which affects the blowing speed of the inert gas, which in turn affects the coarse-grained metal powder The effective decomposition of the powder 800, thus exhausting the excess gas through the pressure control assembly 600, stabilizes the internal pressure of the atomizing chamber 100, thereby ensuring the efficient operation of the device.

In one embodiment, as shown in FIG. 1 , the device further includes a collection assembly 700 , which is communicated with the powder discharge port 110 of the atomization chamber 100 for collecting the refined metal powder. Wherein, in the process of collecting the metal powder, the collecting assembly 700 ensures the airtightness of the atomizing chamber 100 at the same time, so that the device can continue to operate while collecting the metal powder. It should be understood that the collecting assembly 700 may be fixedly connected with the atomizing chamber 100 to store the collected metal powder in an additional container. The collecting assembly 700 can also be detachably connected to the atomizing chamber 100. When the collecting assembly 700 completes the collection of metal powder, the collecting assembly 700 can be disassembled and replaced with another collecting assembly to continue collecting the metal powder. Preferably, the collecting assembly 700 includes a pneumatic butterfly valve and a powder collecting tank, the airtightness of the atomization chamber is maintained during the process of collecting the metal powder through the pneumatic butterfly valve, and the refined metal powder is stored in the powder collecting tank.

The present exemplary embodiment also provides a method for refining the particle size of metal powder. Referring to Figures 1 and 2, the method may include the following steps:

provide a protective atmosphere through an inert gas supply system 500;

Supply coarse-grained metal powder 800 to the atomizing chamber 100 through the powder feeding assembly 200;

In the protective atmosphere, the coarse-grained metal powder 800 is heated to a state of starting to melt by the heating component 300 before the coarse-grained metal powder 800 is decomposed;

In the protective atmosphere, the coarse-grained metal powder 800 is decomposed by blowing an inert gas to the heated coarse-grained metal powder 800 by the inert gas supply system 500 .

Among them, the coarse-grained metal powder 800 in the state of beginning to melt has an outer portion 220 in a liquid state and an inner portion 210 in a solid state.

It should be understood that when the powder feeding component 200 transports the coarse-grained metal powder 800 to the inside of the atomizing chamber 100, the coarse-grained metal powder 800 is heated by the heating component 300 and begins to melt, so as to form a liquid state. The outer portion 820 and the solid inner portion 810, after the coarse-grained metal powder 800 enters the atomization chamber 100 in this state, are impacted by the inert gas provided by the inert gas supply system 500, and complete in the atomization chamber 100 The coarse-grained metal powder 800 is decomposed, whereby one coarse-grained metal powder is decomposed into a plurality of fine-grained metal powders. Wherein, the powder feeding assembly 200 may supply a quantitative amount of coarse-grained metal powder 800 to the heating assembly 300 and the atomization chamber 100 by means of uniform conveying. Therefore, the heating and decomposition process of the coarse-grained metal powder 800 is more stable. The inert gas supply system 500 fills the atomization chamber 100 with an inert gas with a purity greater than 99.999% to a positive pressure of 0.02-0.2 Mpa, so as to satisfy the high-purity inert atmosphere environment of the atomization powder forming process.

It should also be understood that the atomization chamber 100 usually has a powder discharge port 110 . Therefore, after the coarse-grained metal powder 800 is refined, there may also be a step 5: through the powder discharge port 110 of the atomization chamber 100 to refine the powder The resulting metal powder is discharged from the atomization chamber 100 .

In one embodiment, the coarse-grained metal powder 800 is heated by the heating assembly 300 to have an outer portion 820 in a liquid state and an inner portion 810 in a solid state. Preferably, the heating component 300 uses a gradient heating method to heat the coarse-grained metal powder 800 . The gradient heating method refers to dividing the heating area of the heating assembly 300 into different heating sections, each section has a different heating temperature, and the heating temperature or holding time is precisely controlled in sections, and the heating temperature of each section is into an increasing relationship. However, the present invention does not specifically limit the heating method of the heating assembly 300, as long as the coarse-grained metal powder 800 can be heated to a state where it begins to melt. In addition, the height and energy of the heating area of the heating element can be adjusted separately according to the material and particle size of the metal powder. Thereby, the coarse-grained metal powder 800 is heated accurately and rapidly to start melting.

In one embodiment, the heated coarse-grained metal powder 800 is blown with an inert gas with a pressure of 3-8 Mpa and a speed of 50-800 m/s through the inert gas supply system 500, so that the outer part 820 in liquid state changes from the solid state The inner part 810 is separated. The pressure and speed of the inert gas blown by the inert gas supply system 500 can be adjusted to adapt to various types of coarse-grained metal powders.

In one embodiment, the vacuum environment is provided by the vacuum system 400 before the protective atmosphere is provided by the inert gas supply system 500 . Since the coarse-grained metal powder 800 needs to start to melt after being heated, it is easy to react with other reactive gases to destroy the metal powder, so a protective atmosphere needs to be provided during the heating and decomposition of the coarse-grained metal powder 800 . The purity of the inert gas in the protective atmosphere can be improved by vacuuming before injecting the inert gas, and then injecting the inert gas. Specifically, the vacuum system 400 provides a vacuum environment in the atomization chamber 100 to ensure that the ultimate vacuum degree reaches 5×10 ⁻³ Pa.

In one embodiment, the powder feeding speed of the powder feeding assembly 200 and the working power of the heating assembly are adjusted for metal powders of different materials and particle sizes. Specifically, the powder feeding speed may range from 10 to 10000 g/min, and the power range of the heating component may range from 1 to 1000 kW. Thus, the present invention can be applied to various metal powders.

In one embodiment, the discharged fine-grained metal powder 900 is collected by the collection assembly 700 while maintaining the sealing of the atomization chamber 100 . Wherein, in the process of collecting the metal powder, the collecting assembly 700 ensures the airtightness of the atomizing chamber 100 at the same time, so that the device can continue to operate while collecting the metal powder.

The present exemplary embodiment also provides a method for using the device for refining the particle size of metal powder, and the method may include the following steps:

Step 1. Evacuate the atomization chamber 100 through the vacuum system 400 to ensure that the ultimate vacuum degree of the atomization chamber 100 reaches 5×10 ⁻³ Pa;

Step 2. Fill the atomization chamber 100 with an inert gas with a purity greater than 99.999% through the low-pressure gas outlet 520 of the inert gas supply system 500 to a positive pressure of 0.02-0.2 Mpa, which satisfies the high-purity inert atmosphere of the atomization powder forming process ;

Step 3. Turn on the heating assembly 300 to generate a high temperature heating area inside the heating assembly 300, and the heating power of the heating assembly 300 ranges from 1 to 1000 kW;

Step 4. The quantitative coarse-grained metal powder raw material 800 is transported at a constant speed through the powder feeding component 200 to the heating area of the heating component 300. According to the different materials of the metal powder raw material and the melting speed of the external part, the powder feeding speed range is 10~10000g /min, and adjust the temperature field distribution of the heating component 300 according to the different metal powder materials and particle sizes;

Step 5. Under the action of the heating element 300, the coarse-grained metal powder 800 begins to melt, and a liquid outer part 820 and a solid inner part 810 are formed; Under the action of the gas, the solid inner part 810 is decomposed to form a separate metal powder, and the liquid outer part 820 is further broken under the action of the inert gas, and finally realizes the decomposition of the initial one coarse-grained metal powder into a plurality of fine metal powders. Particle size metal powder.

Step 6, collecting the refined metal powder through the collecting component 700 .

For example, the particle size range of the TC4 metal powder prepared by the plasma rotating electrode method is 15~200μm, which is sieved, the metal powder with a particle size of less than 100μm is sealed and stored, and the remaining metal powder with a particle size of 100μm~200μm is stored. Put it on the powder feeding assembly 200 for refining. Specific steps are as follows:

Step 1. Evacuate the atomization chamber 100 through the vacuum system 400 to ensure that the ultimate vacuum degree of the atomization chamber 100 reaches 5×10 ⁻³ Pa;

Step 2. Fill the atomization chamber 100 with an inert gas with a purity greater than 99.999% through the low-pressure gas outlet 520 of the inert gas supply system 500 to a positive pressure of 0.02-0.2 Mpa, which satisfies the high-purity inert atmosphere of the atomization powder forming process ;

Step 3. Turn on the heating assembly 300, and generate a high temperature heating area inside the heating assembly 300 by means of resistance heating. The heating power of the heating assembly 300 is 20kW, the height of the heating area is H=50mm, and the diameter D=φ10mm;

Step 4. The quantitative coarse-grained metal powder raw material 800 is transported at a constant speed through the powder feeding component 200 to the heating area of the heating component 300. According to the melting speed of the metal powder, the powder feeding speed is 10g/min, and the corresponding heating time is 0.5S , and adjust the temperature field distribution of the heating assembly 300 so that the temperature of the metal powder reaches 2000°C;

Step 5. Under the action of the heating element 300, the coarse-grained metal powder 800 begins to melt, and a liquid outer part 820 and a solid inner part 810 are formed. Taking the metal powder with a particle size of 200 μm as an example, the metal powder 800 is in a liquid state. The diameter of the outer part 820 is 80-200 μm. Due to the short heating time, the diameter of the solid inner part 810 is 80 μm. At this time, under the action of gravity, the metal powder in the starting melting state falls and leaves the heating element 300 , and enter the high-speed inert gas action area;

Step 6, adjust the high pressure gas outlet 510 of the inert gas supply system 500, the output inert gas pressure is 3Mpa, and the speed is 100m/s; under the action of the high-speed high-pressure gas, the solid inner part 810 is decomposed to form a separate metal powder, which is The liquid outer part 820 is further broken down under the action of the inert gas, and finally realizes the decomposition of the initial one coarse-grained metal powder into a plurality of fine-grained metal powders.

Step 7: Collect the refined metal powder through the collecting component 700 .

For example, the particle size range of W metal powder prepared by the plasma rotating electrode method is 15~200 μm, which is sieved, the metal powder with a particle size of 100 μm or less is sealed and stored, and the remaining metal powder with a particle size of 100 μm~200 μm is stored. Put it on the powder feeding assembly 200 for refining. Specific steps are as follows:

Step 1. Evacuate the atomization chamber 100 through the vacuum system 400 to ensure that the ultimate vacuum degree of the atomization chamber 100 reaches 5×10 ⁻³ Pa;

Step 2. Fill the atomization chamber 100 with an inert gas with a purity greater than 99.999% through the low-pressure gas outlet 520 of the inert gas supply system 500 to a positive pressure of 0.02-0.2 Mpa, which satisfies the high-purity inert atmosphere of the atomization powder forming process ;

Step 3. Turn on the heating assembly 300, and generate a high temperature heating area inside the heating assembly 300 by means of resistance heating. The heating power of the heating assembly 300 is 180kW, the height of the heating area is H=100mm, and the diameter D=φ20mm;

Step 4. The quantitative coarse-grained metal powder raw material 800 is delivered to the heating area of the heating component 300 through the powder feeding component 200 at a constant speed. According to the melting speed of the metal powder, the powder feeding speed is 1000g/min, and the corresponding heating time is 2S. And adjust the temperature field distribution of the heating assembly 300 to make the temperature of the metal powder reach 5000°C;

Step 5. Under the action of the heating element 300, the coarse-grained metal powder 800 begins to melt, and a liquid outer part 820 and a solid inner part 810 are formed. Taking the metal powder with a particle size of 200 μm as an example, the metal powder 800 is in a liquid state. The diameter of the outer part 820 is 100-200 μm. Due to the short heating time, the diameter of the solid inner part 810 is 100 μm. At this time, under the action of gravity, the metal powder in the starting melting state falls and leaves the heating element 300 , and enter the high-speed inert gas action area;

Step 6. Adjust the high-pressure gas outlet 510 of the inert gas supply system 500, and the output inert gas pressure is 8Mpa and the speed is 800m/s; under the action of the high-speed and high-pressure gas, the solid inner part 810 is decomposed to form a separate metal powder, which is The liquid outer part 820 is further broken down under the action of the inert gas, and finally realizes the decomposition of the initial one coarse-grained metal powder into a plurality of fine-grained metal powders.

Step 7: Collect the refined metal powder through the collecting component 700 .

It should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", The orientation or positional relationship indicated by "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", etc. is based on The orientation or positional relationship shown in the accompanying drawings is only for the convenience of describing the embodiments of the present invention and simplifying the description, rather than indicating or implying that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot It is understood as a limitation on the embodiments of the present invention.

In addition, the terms "first" and "second" are only used for descriptive purposes, and should not be construed as indicating or implying relative importance or implying the number of indicated technical features. Thus, a feature defined as "first", "second" may expressly or implicitly include one or more of that feature. In the description of the embodiments of the present invention, "plurality" means two or more, unless otherwise expressly and specifically defined.

In the embodiments of the present invention, unless otherwise expressly specified and limited, terms such as “installation”, “connection”, “connection”, and “fixation” should be understood in a broad sense. For example, it may be a fixed connection or a It can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, and it can be the internal communication of the two elements or the interaction relationship between the two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

In the embodiments of the present invention, unless otherwise expressly specified and limited, the first feature "on" or "under" the second feature may include the first and second features in direct contact, or may include the first and second features The two features are not in direct contact but through another feature between them. Also, the first feature being "above", "over" and "above" the second feature includes the first feature being directly above and obliquely above the second feature, or simply means that the first feature is level higher than the second feature. The first feature is "below", "below" and "below" the second feature includes the first feature being directly below and diagonally below the second feature, or simply means that the first feature has a lower level than the second feature.

In the description of this specification, description with reference to the terms "one embodiment," "some embodiments," "example," "specific example," or "some examples", etc., mean specific features described in connection with the embodiment or example , structure, material or feature is included in at least one embodiment or example of the present invention. In this specification, schematic representations of the above terms are not necessarily directed to the same embodiment or example. Furthermore, the particular features, structures, materials or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. Furthermore, those skilled in the art may combine and combine the different embodiments or examples described in this specification.

Other embodiments of the invention will readily occur to those skilled in the art upon consideration of the specification and practice of the invention disclosed herein. This application is intended to cover any variations, uses, or adaptations of the invention that follow the general principles of the invention and include common knowledge or conventional techniques in the art not disclosed by the invention . The specification and examples are to be regarded as exemplary only, with the true scope and spirit of the invention being indicated by the appended claims.

Claims (10)

1. An apparatus for refining a particle size of a metal powder, comprising:

an atomization chamber;

the powder feeding assembly is communicated with the atomizing chamber and is used for providing the atomizing chamber with the coarse-grain-size metal powder;

a heating unit provided in a communication path between the powder feeding unit and the atomizing chamber, for heating the coarse-grained metal powder to a state where the coarse-grained metal powder starts to melt before the coarse-grained metal powder is decomposed;

an inert gas supply system in communication with the atomizing chamber, the heating assembly, the inert gas supply system decomposing the coarse-particle-size metal powder by blowing an inert gas to the heated coarse-particle-size metal powder and for providing a protective atmosphere upon heating and decomposition of the coarse-particle-size metal powder.

2. The apparatus of claim 1, wherein the powder feed assembly comprises a feed end containing the coarse-grained metal powder and a delivery end in communication with the feed end, the atomization chamber being provided with a cylindrical interface at a top thereof, the delivery end of the powder feed assembly being in communication with the atomization chamber through the cylindrical interface.

3. The apparatus of claim 1, wherein the top of the atomization chamber is provided with a cylindrical port, the cylindrical port is provided with a sandwich, and the heating assembly is disposed in the sandwich of the cylindrical port.

4. The apparatus of claim 1, wherein the inert gas supply system comprises an inert gas source, a low pressure gas outlet end and a high pressure gas outlet end, the inert gas source is configured to supply inert gas to the low pressure gas outlet end and the high pressure gas outlet end, the low pressure gas outlet end and the high pressure gas outlet end are both in communication with the atomizing chamber, and the high pressure gas outlet end is disposed below the heating assembly.

5. The apparatus of claim 3, wherein the heating assembly has a height ranging from 10 to 200mm, a diameter ranging from 2 to 100mm, and a power ranging from 1 to 1000 kW.

6. The apparatus of claim 3, wherein the height, diameter and operating power of the heating assembly are related to the material and particle size of the coarse-grained metal powder.

7. The apparatus of any one of claims 1-6, wherein the powder feeding speed of the powder feeding assembly is in a range of 10-10000 g/min, and is related to the operating power of the heating assembly.

8. A method for refining the particle size of metal powders using the apparatus of any one of claims 1 to 7, comprising:

providing a protective atmosphere through the inert gas supply system;

providing the coarse-sized metal powder to the atomization chamber through the powder feed assembly;

heating, by the heating assembly, the coarse-grained metal powder to a state that begins to melt before the coarse-grained metal powder is decomposed in the protective atmosphere;

blowing an inert gas to the heated coarse-particle-size metal powder by the inert gas supply system in the protective atmosphere to decompose the coarse-particle-size metal powder;

wherein the coarse-grained metal powder in a state of starting to melt has an outer portion in a liquid state and an inner portion in a solid state.

9. The method according to claim 8, wherein the outer part in the liquid state is separated from the inner part in the solid state by blowing an inert gas having a pressure of 3 to 8Mpa and a velocity of 50 to 800m/s to the heated coarse-grained metal powder by an inert gas supply system.

10. Method according to any of claims 8 or 9, characterized in that the powder feeding speed of the powder feeding assembly and the operating power of the heating assembly are adjusted for different materials and particle sizes of the metal powder.

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