Radio frequency plasma-high frequency inductance composite gas atomization powder making device and method

Abstract

The invention relates to a radio frequency plasma-high frequency inductance composite gas atomization powder making device and method, and the device comprises an atomizing nozzle which is provided with a nozzle center hole; an opening is formed in one end of the restraining structure, the opening end is inserted into the nozzle center hole, and a gas inlet used for introducing plasma gas is formed in the side wall of the restraining structure; the high-frequency induction coil is arranged in the restraint structure and used for being arranged outside the alloy material in a sleeving mode and enabling the alloy material to be melted at a high temperature; the radio frequency plasma generator is arranged in the restraint structure and is arranged below the high-frequency induction coil, and the position of the air inlet is higher than that of the radio frequency plasma generator; and the radio frequency induction coil is arranged outside the constraint structure in a sleeving manner and corresponds to the radio frequency plasma generator, and the radio frequency induction coil is used for exciting the plasma gas into radio frequency plasma. The method has the effect of reducing the powder granularity on the basis of improving the powder yield.

Description

Technical Field

[0001] This application relates to the field of gas atomization powder making apparatus, and in particular to a radio frequency plasma-high frequency inductor composite gas atomization powder making apparatus and method. Background Technology

[0002] Gas atomization is a powder preparation method that uses a rapidly moving fluid (atomizing medium) to impact or otherwise break down liquid metal or alloy into fine droplets, which are then condensed into solid powder. Among all metal powder preparation methods, gas atomization is the most widely used in the field, as the particle size of metal powders prepared using this method can cover almost all application requirements.

[0003] Gas atomization powder production technology can be divided into vacuum induction melting atomization (VIGA) with a crucible and electrode induction melting gas atomization (EIGA) without a crucible. Among them, EIGA is widely used in powder production processes. It involves melting metal in an induction melting coil at a certain vertical feed rate. The molten metal flows through the central hole of the atomizer and is impacted by a high-speed inert gas flow to form metal powder particles. However, due to the low superheat of the melt in the EIGA powder production process, the prepared powder particles are relatively coarse and the yield is relatively low. Summary of the Invention

[0004] In order to improve powder yield and reduce powder particle size, this application provides a radio frequency plasma-high frequency inductive composite gas atomization powder preparation device and method.

[0005] Firstly, the radio frequency plasma-high frequency inductor composite gas atomization powder making device provided in this application adopts the following technical solution: A radio frequency plasma-high frequency inductive composite gas atomization powder preparation device, comprising: The atomizing nozzle has a central hole and an air nozzle that communicates with the central hole for inert airflow to enter. The constraint structure has an open end, which is inserted into the central hole of the nozzle. An air inlet for introducing plasma gas is provided on the side wall of the constraint structure. A high-frequency induction coil is disposed within the constraint structure and is used to be fitted over the outside of the alloy material to allow the alloy material to melt at high temperature; A radio frequency plasma generator is disposed inside the constraint structure and below the high frequency induction coil, wherein the air inlet is positioned higher than the radio frequency plasma generator; A radio frequency induction coil is sleeved outside the constraint structure and corresponds to the radio frequency plasma generator. The radio frequency induction coil is used to excite the plasma gas into radio frequency plasma. There is a gap between the radio frequency plasma generator and the inner wall of the constraint structure. The side wall of the constraint structure is also provided with a side gas inlet for introducing plasma gas into the gap. The side gas inlet is located above the radio frequency induction coil and multiple inlets are arranged around the axis of the constraint structure.

[0006] By employing the above technical solution, during the preparation of metal powder, alloy material is inserted into a high-frequency induction coil inside a constraint structure, and plasma gas is introduced into the air inlet. The alloy droplets, melted by the induction of the high-frequency induction coil, drip along with the plasma gas into a radio frequency plasma generator. A radio frequency induction coil, mounted outside the generator, excites the plasma gas to form radio frequency plasma. During its descent, the radio frequency plasma further heats the alloy droplets it encapsulates using its high temperature, significantly increasing the superheat of the droplets. The alloy droplets then enter an atomizing spray... Inside the nozzle, the high-speed flow of inert gas ejected from the nozzle breaks up the alloy droplets, atomizing them into fine powder. This reduction in powder particle size effectively improves the yield of fine powder. Introducing plasma gas into the gap between the radio frequency plasma and the confinement structure restricts the flow of the high-temperature radio frequency plasma, ensuring it maintains a stable direction. This reduces the probability of the high-temperature radio frequency plasma splashing onto the inner wall of the confinement structure and burning it out. The introduced edge gas surrounds the radio frequency plasma in a ring, further reducing the probability of the high-temperature radio frequency plasma burning out the confinement structure.

[0007] Preferably, the air inlet is located above the high-frequency induction coil, and multiple inlets are provided around the axis of the constraint structure.

[0008] By adopting the above technical solution, the air inlet is set above the high-frequency induction coil. The introduced plasma gas has sufficient distance and time to encapsulate the molten alloy droplets, and the plasma gas has formed a stable flow rate when it merges with the alloy droplets, resulting in better fusion effect. This facilitates the full excitation of the plasma gas after it is dropped into the radio frequency plasma generator, and the encapsulated alloy droplets are fully heated, which is beneficial to obtaining a higher fine powder yield and reducing the particle size of the metal powder.

[0009] Preferably, a portion of the radio frequency induction coil is located below the radio frequency plasma generator.

[0010] By adopting the above technical solution, a portion of the radio frequency induction coil is placed below the radio frequency plasma generator to ensure that the plasma gas is fully excited to form high-temperature radio frequency plasma, and to ensure that the alloy droplets are fully and uniformly heated, so as to obtain a higher fine powder yield.

[0011] Preferably, the constraint structure is a water-cooled quartz sleeve.

[0012] By adopting the above technical solution, the confinement structure is used to confine the plasma gas and the high-temperature radio frequency plasma excited by the radio frequency induction coil, so that the plasma gas and radio frequency plasma can operate stably inside the confinement structure. The quartz material has the properties of hardness and high temperature resistance, which can further reduce the probability of the high-temperature radio frequency plasma burning off the sidewalls of the confinement structure.

[0013] Preferably, there is a gas supply gap between the outer wall of the constraint structure and the inner wall of the nozzle center hole, and the gas supply gap is used to introduce inert gas.

[0014] By adopting the above technical solution, since the gas flow rate in the central hole of the nozzle is relatively large during the atomization process, and is much greater than the flow rate of plasma and argon in the radio frequency plasma, an additional gas supply path is required. Inert gas is introduced from the gas supply gap to prevent the plasma flame from going out and to ensure the stable operation of the atomization process.

[0015] Preferably, a sealing ring is installed on the top of the constraint structure, and the alloy material is used to insert and clamp in the through hole of the sealing ring. The axis of the through hole coincides with the axis of the constraint structure, and the two ends of the high-frequency induction coil are inserted into the sealing holes on the side wall of the constraint structure.

[0016] By adopting the above technical solution and setting a sealing ring, the sealing performance of the constraint structure is ensured while guaranteeing that the alloy material is vertically inserted into the high-frequency induction coil. This prevents the plasma gas from overflowing from the constraint structure and ensures the stable operation of the plasma gas within the constraint structure. The two ends of the high-frequency induction coil are inserted and fixed in the sealing holes of the constraint structure, which facilitates the fixing of the high-frequency induction coil and effectively ensures the sealing performance of the constraint structure.

[0017] Preferably, the alloy material is an alloy rod with a diameter of 50-80 mm, and the end of the alloy rod inserted into the high-frequency induction coil is inverted conical, and the high-frequency induction coil is also inverted conical.

[0018] By adopting the above technical solution, the alloy droplets that have not reached the optimal atomization temperature can be further heated due to the radio frequency induction coil installed below, so that the superheat of the alloy droplets is increased to more than 250 degrees Celsius. Thus, when melting alloy materials at high temperature, finer metal powder can be produced even using a thicker alloy rod of 50~80mm, with a higher powder yield and higher powder production efficiency compared to using wire.

[0019] Secondly, this application provides a method for preparing powder by radio frequency plasma-high frequency inductor composite gas atomization, which adopts the following technical solution: A method for powder preparation by radio frequency plasma-high frequency inductive composite gas atomization includes the following steps: The alloy material is inserted into the high-frequency induction coil; Plasma gas is introduced into the air inlet and the side air inlet; Inert gas is introduced into the air supply gap and the atomizing nozzle; A high-frequency induction coil melts the tip of the alloy material, and plasma gas envelops the alloy droplets as they are injected into the radio frequency plasma generator. Radio frequency induction coils excite plasma gas into high-temperature radio frequency plasma; High-temperature radio frequency plasma heats the alloy droplets; The superheated alloy droplets are injected into the central hole of the nozzle and impacted by the high-pressure supersonic inert airflow ejected from the atomizing nozzle, forming metal powder with a smaller particle size.

[0020] By adopting the above technical solution, an RF induction coil is added below the high-frequency induction coil. The RF induction coil heats the plasma gas introduced from the air inlet into high-temperature RF plasma. Since the plasma has already wrapped the alloy droplets before entering the RF plasma generator, the high-temperature RF plasma can further heat the wrapped alloy droplets, increasing the superheat of the alloy droplets. As the superheat of the alloy material increases, the spheroidization degree of the metal powder increases, the average particle size decreases, and finer metal powder can be obtained, as well as the powder yield can be improved.

[0021] In summary, this application includes at least one of the following beneficial technical effects: This application sets up a radio frequency induction coil below a high frequency induction coil to excite the plasma gas that is introduced into the confinement structure and encapsulates the alloy droplets to form a high-temperature radio frequency plasma gas. The high-temperature plasma gas further heats the alloy droplets, greatly increasing the superheat of the alloy droplets. The alloy droplets heated to a higher temperature are introduced into an atomizing nozzle and impacted by a high-speed inert gas flow to form finer metal powder. By placing the air inlet above the high-frequency induction coil, the plasma gas has sufficient distance and time to envelop the alloy droplets, and the plasma gas has already formed a stable flow rate when it merges with the droplets, resulting in a better fusion effect with the alloy droplets. By opening a peripheral gas inlet near the radio frequency induction coil and introducing plasma gas through the peripheral gas inlet, the high-temperature radio frequency plasma can be confined within a certain space and formed in a stable direction, which can effectively reduce the probability of the high-temperature radio frequency plasma flowing and burning the inner wall of the confinement structure. Attached Figure Description

[0022] Figure 1 This is a cross-sectional schematic diagram of the powder-making apparatus of this application.

[0023] Figure 2yes Figure 1 A magnified view of the structure at point A in the middle.

[0024] Figure 3 This is a process flow diagram of the powder preparation method of this application.

[0025] Explanation of reference numerals in the attached drawings: 1. Atomizing nozzle; 11. Nozzle center hole; 12. Air nozzle; 2. Constraint structure; 21. Air inlet; 22. Side air inlet; 23. Sealing ring; 3. High-frequency induction coil; 4. Radio frequency plasma generator; 5. Radio frequency induction coil; 6. Alloy material; 7. Alloy droplet; 8. Radio frequency plasma; 9. Air supply gap; 10. Water cooling layer. Detailed Implementation

[0026] The following is in conjunction with the appendix Figure 1-3 This application will be described in further detail.

[0027] This application discloses a radio frequency plasma-high frequency inductor composite gas atomization powder-making device. (Refer to...) Figure 1 The radio frequency plasma-high frequency inductive composite gas atomization powder-making device includes a constraint structure 2, a high frequency induction coil 3 disposed inside the constraint structure 2, a radio frequency plasma generator 4 disposed inside the constraint structure 2 and located below the high frequency induction coil 3, and a radio frequency induction coil 5 sleeved outside the constraint structure 2. The radio frequency induction coil 5 corresponds to the radio frequency plasma generator 4. The constraint structure 2 is a columnar structure with one open end, and the open end of the constraint structure 2 is inserted into the nozzle center hole 11 of the atomizing nozzle 1.

[0028] Alloy material 6 passes through the sealing end of constraint structure 2 and is vertically inserted into high-frequency induction coil 3. It is then melted by the induction of high-frequency induction coil 3 to form alloy droplets 7. Specifically, both ends of high-frequency induction coil 3 are inserted into pre-reserved sealing holes in constraint structure 2 and sealed with sealant. A sealing ring 23 is fixed to the sealing end of constraint structure 2. The sealing ring 23 has a through hole through which alloy material 6 passes. The axis of the through hole, the axis of high-frequency induction coil 3, and the axis of constraint structure 2 coincide. When alloy material 6 passes through the through hole of sealing ring 23, it is held by sealing ring 23 to fix its position while ensuring the sealing of constraint structure 2. The alloy droplets 7, which have not yet reached the optimal atomization temperature, drip into radio frequency plasma generator 4 under the action of gravity.

[0029] To facilitate the dripping of the alloy droplet 7 and to constrain its diameter, at least one end of the alloy material 6 is a pointed tip with an inverted cone shape at an angle of approximately 60°. The high-frequency induction coil 3 is also designed to be an inverted cone shape, following the angle of the pointed tip.

[0030] An inlet 21 for introducing plasma gas is provided on the side wall of the constraint structure 2, and the inlet 21 is located above the radio frequency plasma generator 4. The plasma gas introduced into the constraint structure 2 encapsulates the alloy droplets 7, and when flowing through the radio frequency plasma generator 4, it is excited by the radio frequency induction coil 5 to form high-temperature radio frequency plasma 8. The temperature of the radio frequency plasma 8 is extremely high, reaching a maximum of 9000K. The radio frequency plasma 8 further heats the alloy droplets 7 it encapsulates, greatly increasing the superheat of the alloy droplets 7, which can exceed 250 degrees Celsius. Then, these alloy droplets 7, heated to a higher temperature, drip into the central hole 11 of the nozzle, and are broken into fine powder particles by the high-pressure supersonic inert gas flow introduced from several nozzles 12 of the atomizing nozzle 1, thereby effectively reducing the powder particle size. At the same time, because the obtained metal powder is finer, the yield of fine powder is also higher.

[0031] The type of plasma gas is not required, as long as it can be excited by high temperature to become high-temperature radio frequency plasma 8. Common plasma gases mainly include air, oxygen, argon, argon-hydrogen mixture, and carbon tetrafluoride (CF4). The specific plasma gas is changed according to the type of metal powder material being prepared. Among them, argon is the most common plasma gas and is also an inert gas. This application uses the example of introducing argon into both the inlet 21 and the nozzle 12 as an example.

[0032] Multiple air inlets 21 are arranged around the axis of the constraint structure 2 to facilitate the all-round envelopment of the alloy droplets 7. To ensure that the alloy droplets 7 are completely immersed in the plasma gas, the air inlets 21 are positioned higher than the high-frequency induction coil 3, and several air inlets 21 are located at the same height, which facilitates the formation of a stable airflow of plasma gas within the constraint structure 2, ensuring stable operation of the powder making process. At the same time, the plasma gas has sufficient distance and time to envelop the molten alloy droplets 7. When the alloy droplets 7, encased in plasma gas, are dropped into the radio frequency plasma generator 4, they can be fully heated by the radio frequency plasma 8, which is beneficial for obtaining lower powder particle size and higher fine powder yield.

[0033] Furthermore, in order to ensure that the argon gas introduced through the inlet 21 can encapsulate the alloy droplet 7 as it drips, the argon gas flow rate should be matched with the melting and dripping speed of the alloy droplet 7. The melting speed of the alloy droplet 7 is related to the number of turns of the high-frequency induction coil 3 and the diameter of the alloy material 6. Since this application utilizes radio frequency plasma 8 to heat the alloy droplet 7 to a higher temperature, a finer metal powder particle size can be obtained. Therefore, this application can use a rod-shaped alloy material 6, which can improve powder production efficiency while obtaining a finer powder particle size. This application uses an alloy rod diameter of 50-80 mm and a high-frequency induction coil 3 with 3-5 turns as an example for illustration. Correspondingly, the argon gas flow rate is set to approximately 15 L / min, and the diameter of the inlet 21 is set to approximately 10 mm.

[0034] To ensure that all plasma gas is excited, the radio frequency induction coil 5 is located in the lower middle part of the radio frequency plasma generator 4, with a portion of the radio frequency induction coil 5 positioned below the radio frequency plasma generator 4. Incompletely excited plasma gas dripping from the radio frequency plasma generator 4 is re-excited by this portion of the radio frequency induction coil 5 to form high-temperature radio frequency plasma 8, which continues to heat the alloy droplets 7 encased within it. This process facilitates heating all the alloy droplets 7 immersed in the radio frequency plasma 8, resulting in a higher yield of fine powder.

[0035] The radio frequency plasma generator 4 is integrally formed with the constraint structure 2, and the top of the radio frequency plasma 8 generating gas is connected to the side wall of the constraint structure 2. There is a certain gap between the radio frequency plasma generator 4 and the inner wall of the constraint structure 2. The radio frequency plasma 8 generated by the radio frequency induction coil 5 is a high-temperature and unstable spark. During the excitation, it tends to run wildly inside the radio frequency plasma generator 4. Especially when it is excited by a part of the radio frequency induction coil 5 located below the radio frequency plasma generator 4, the high-temperature radio frequency plasma 8 can easily sputter directly onto the inner wall of the constraint structure 2, thereby burning the inner wall of the constraint structure 2, which will shorten the service life of the constraint structure 2. In order to further constrain the high-temperature radio frequency plasma 8, a side gas inlet 22 for introducing plasma gas (argon gas is used as an example in this application) is opened on the side wall of the constraint structure 2. Multiple side gas inlets 22 are arranged at intervals around the axis of the constraint structure 2. Argon gas is introduced through the side gas inlet 22 and flows into the gap between the radio frequency plasma generator 4 and the constraint structure 2, forming a stable airflow. This stable airflow confines the radio frequency plasma 8 within the space it forms and can prevent the sputtered radio frequency plasma 8 from contacting the inner wall of the constraint structure 2, reducing the probability of the inner wall of the constraint structure 2 being burned.

[0036] To further reduce the probability of the constraint structure 2 being burned out, the material of the constraint structure 2 should also be a material with high strength, high hardness and high temperature resistance. Therefore, the constraint structure 2 of this application is a quartz water-cooled jacket made of quartz material, and the side wall of the quartz water-cooled jacket is a double-layer structure with a water-cooling layer 10 between the two layers, so that the constraint structure 2 has a good cooling and heat insulation effect, and avoids the heat of the internal radio frequency plasma 8 from being transferred outward, causing the side wall of the constraint structure 2 to get hot.

[0037] Because the gas velocity in the nozzle center hole 11 is relatively high during atomization, and much greater than the flow rates of plasma and argon in the radio frequency plasma 8, an additional gas supply path is required. Therefore, the diameter of the nozzle center hole 11 is larger than the outer diameter of the constraint structure 2, resulting in a gas supply gap 9 between the outer wall of the constraint structure 2 and the inner wall of the nozzle center hole 11. During metal powder preparation, inert gas is introduced into the gas supply gap 9 to prevent the plasma flame from extinguishing and to ensure stable operation of the atomization process.

[0038] The implementation principle of the radio frequency plasma-high frequency inductive composite gas atomization powder preparation device in this application embodiment is as follows: When preparing metal powder, the tip of the rod-shaped alloy material 6 is vertically inserted into the high frequency induction coil 3 through the through hole of the top sealing ring 23, and argon gas is introduced into the air inlet 21, the side gas inlet 22, and the gas replenishment gap 9, and the flow rate of the introduced argon gas is controlled respectively. After the alloy material 6 is melted by the induction of the high frequency induction coil 3, it forms alloy droplets 7. The argon gas introduced from the air inlet 21 encapsulates the alloy droplets 7 and drips them into the radio frequency plasma generator 4 together. The argon gas is excited by the radio frequency plasma coil to become high-temperature radio frequency plasma 8. The high-temperature radio frequency plasma 8 further heats the alloy droplets 7, increasing the superheat of the alloy droplets 7. Thus, when the alloy droplets 7 and the radio frequency plasma 8 are introduced into the atomizing nozzle 1, they are crushed into fine powder particles by the impact of the high-pressure supersonic argon gas flow, which can effectively reduce the particle size of the metal powder and improve the yield of fine powder.

[0039] This application also discloses a method for producing powder using radio frequency plasma-high frequency inductor composite gas atomization. (Refer to...) Figure 3 The radio frequency plasma-high frequency inductive composite gas atomization powder preparation method includes the following steps: S1: Insert the alloy material 6 into the high-frequency induction coil 3.

[0040] S2: Introduce plasma gas into the air inlet 21 and the side air inlet 22.

[0041] S3: Inert gas is introduced into the air supply gap 9 and the atomizing nozzle 1.

[0042] S4: The high-frequency induction coil 3 melts the tip of the alloy material 6, and the plasma gas envelops the alloy droplet 7 and drips it into the radio frequency plasma generator 4.

[0043] S5: The radio frequency induction coil 5 excites the plasma gas into high-temperature radio frequency plasma 8.

[0044] S6: High-temperature plasma heats the alloy droplet 7.

[0045] S7: The alloy droplets 7 with higher superheat are dropped into the central hole 11 of the nozzle and impacted by the high-pressure supersonic inert airflow ejected from the atomizing nozzle 1 to form metal powder with a smaller particle size.

[0046] The above are all preferred embodiments of this application, and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. A radio frequency plasma-high frequency inductive composite gas atomization powder-making device, characterized in that: include: The atomizing nozzle (1) has a nozzle center hole (11) and an air nozzle (12) connected to the nozzle center hole (11) for inert airflow to enter; The constraint structure (2) has an open end, and the open end is inserted into the central hole (11) of the nozzle. An air inlet (21) for introducing plasma gas is provided on the side wall of the constraint structure (2). A high-frequency induction coil (3) is disposed inside the constraint structure (2) and is used to be sleeved on the outside of the alloy material (6) so that the alloy material (6) melts at high temperature; A radio frequency plasma generator (4) is disposed inside the constraint structure (2) and below the high frequency induction coil (3), wherein the air inlet (21) is positioned higher than the radio frequency plasma generator (4); A radio frequency induction coil (5) is sleeved outside the constraint structure (2) and corresponds to the radio frequency plasma generator (4). The radio frequency induction coil (5) is used to excite the plasma gas into radio frequency plasma (8). There is a gap between the radio frequency plasma generator (4) and the inner wall of the constraint structure (2). The side wall of the constraint structure (2) is also provided with a side gas inlet (22) for introducing plasma gas into the gap. The side gas inlet (22) is located above the radio frequency induction coil (5) and multiple inlets are arranged around the axis of the constraint structure (2).

2. The radio frequency plasma-high frequency inductive composite gas atomization powder making device according to claim 1, characterized in that: The air inlet (21) is located above the high-frequency induction coil (3) and has multiple openings around the axis of the constraint structure (2).

3. The radio frequency plasma-high frequency inductive composite gas atomization powder making device according to claim 1, characterized in that: Part of the radio frequency induction coil (5) is located below the radio frequency plasma generator (4).

4. The radio frequency plasma-high frequency inductive composite gas atomization powder making device according to claim 1, characterized in that: The constraint structure (2) is a water-cooled quartz sleeve.

5. The radio frequency plasma-high frequency inductive composite gas atomization powder making device according to claim 1, characterized in that: There is a gas filling gap (9) between the outer wall of the constraint structure (2) and the inner wall of the nozzle center hole (11), and the gas filling gap (9) is used to introduce inert gas.

6. The radio frequency plasma-high frequency inductive composite gas atomization powder making device according to claim 1, characterized in that: A sealing ring (23) is installed on the top of the constraint structure (2). The alloy material (6) is used to insert and clamp in the through hole of the sealing ring (23). The axis of the through hole coincides with the axis of the constraint structure (2). The two ends of the high-frequency induction coil (3) are inserted into the sealing holes on the side wall of the constraint structure (2).

7. The radio frequency plasma-high frequency inductive composite gas atomization powder making device according to claim 6, characterized in that: The alloy material (6) is an alloy rod with a diameter of 50~80mm. The end of the alloy rod inserted into the high-frequency induction coil (3) is inverted cone shape, and the high-frequency induction coil (3) is also inverted cone shape.

8. A method for producing powder by radio frequency plasma-high frequency inductive composite gas atomization, characterized in that: Includes the following steps: Insert the alloy material (6) into the high-frequency induction coil (3); Plasma gas is introduced into the air inlet (21) and the side air inlet (22); Inert gas is introduced into the air supply gap (9) and the atomizing nozzle (1); The high-frequency induction coil (3) melts the tip of the alloy material (6), and the plasma gas encapsulates the alloy droplet (7) and drips it into the radio frequency plasma generator (4); The radio frequency induction coil (5) excites the plasma gas into high-temperature radio frequency plasma (8); High-temperature radio frequency plasma (8) heats the alloy droplet (7); The alloy droplets (7) with higher superheat are dropped into the central hole (11) of the nozzle and impacted by the high-pressure supersonic inert airflow ejected by the atomizing nozzle (1) to form metal powder with lower particle size.

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