Device for preparing alloy powder by gas atomization and atomization system containing the same

Abstract

The present invention discloses a device for preparing alloy powder by gas atomization and an atomization system containing the same. The device includes an atomizing nozzle and an induction coil, wherein the atomizing nozzle includes a containing chamber, wherein the containing chamber is used to contain at least a portion of the induction coil, and an opening is also provided at the bottom of the atomizing nozzle as a gas ejection port, and the gas ejection port is oriented toward the axial direction of the induction coil. The melting point of the parent material is in the containing chamber, that is, in the atomizing nozzle, which shortens the distance between the melting point and the atomization point, greatly improving the fine powder recovery rate. And there is no need to modify the atomizing chamber, and the induction coil is normally installed from the upper smelting chamber, reducing the equipment processing cost. In addition, the airflow field is prevented from directly acting on the induction coil, and the powder making process is more stable. During the powder making process, the prepared alloy powder will not stick to the induction coil, protecting the use of the induction coil.

Description

Technical Field

[0001] The invention relates to a device for preparing alloy powder by gas atomization and an atomization system comprising the device. Background Art

[0002] At present, the mainstream technology for titanium alloy powder making in the market is electrode vacuum induction melting gas atomization powder making (EIGA). The titanium alloy base material specifications used by traditional EIGA gas atomization powder making equipment are φ50-600mm rods, and the rods are suspended on the top of the gas atomization nozzle. After the induction coil melts the tip of the base material, the molten metal falls freely, passes through the middle hole of the atomization nozzle, and is broken by the high-pressure inert gas at the bottom of the atomization nozzle to form droplets. The droplets are naturally cooled and spheroidized to form spherical powder. However, since the melting point is far away from the atomization point, the molten metal falls freely from the melting point to the atomization point, and the viscosity increases due to heat loss. Finally, the same energy inert gas cannot fully break up the molten metal, resulting in a low yield of fine powder.

[0003] In addition, there is also a technical solution in the prior art to place an induction coil under the atomizing nozzle to shorten the distance between the melting point of the base material and the atomizing point. However, there are still the following three problems:

[0004] 1. The induction coil is placed at the bottom of the nozzle, that is, the induction coil is placed in the atomization chamber of the powder making equipment (in the gas atomization powder making equipment, the bottom of the atomization nozzle is the atomization chamber). Conventionally, the induction coil is installed from the existing window in the smelting chamber (the top of the atomization nozzle). Changing to the atomization chamber installation not only requires an additional installation port (affecting the air tightness and increasing the processing cost of the powder making equipment), but also cannot ensure the centering degree every time the atomization nozzle is installed. Once the centering degree cannot be guaranteed, the liquid will be tilted by the electromagnetic force during the smelting process, resulting in a disordered atomization state;

[0005] 2. The induction coil is placed at the bottom of the atomizing nozzle, that is, in the impact range of high-pressure inert gas. During the atomization process, the shaking of the induction coil will also lead to powder production failure. In addition, the induction coil is in the atomization airflow field, which will also cause new uncertain effects on the airflow field.

[0006] 3. Because the induction coil is in the atomization chamber, it is inevitable that powder will fly and stick to the coil during the powder making process. If the temperature of the powder is high enough, it can burn through the coil. Even if the temperature is not enough to damage the coil, after long-term accumulation, after the insulation on the coil surface fails, it will still short-circuit and "break down" the coil. That is, there is a great deal of uncontrollable components in the powder making process.

[0007] Therefore, the prior art has the following defects: in traditional atomization equipment, the distance between the melting point and the atomization point of the base material is relatively long, and the fine powder recovery rate is low; and in the "bottom-mounted" scheme of the induction coil, the coil and the airflow field interfere with each other, resulting in an unstable powder making process. Summary of the invention

[0008] The technical problem to be solved by the present invention is to overcome the defects of low fine powder yield and unstable powder making process in the prior art, and to provide a device for preparing alloy powder by gas atomization and an atomization system comprising the same.

[0009] The present invention solves the above technical problems through the following technical solutions:

[0010] The present invention provides a device for preparing alloy powder by gas atomization, which includes an atomizing nozzle and an induction coil. The atomizing nozzle includes a accommodating chamber, which is used to accommodate at least a part of the induction coil. The bottom of the atomizing nozzle is also provided with an opening as a gas outlet, and the gas outlet is oriented toward the axial direction of the induction coil.

[0011] In this scheme, the above-mentioned structural form is adopted. On the first hand, the induction coil is placed in the accommodating chamber, and the base material is placed in the induction coil for heating, that is, the melting point of the base material is in the accommodating chamber, that is, in the atomizing nozzle, but not above the atomizing nozzle, which shortens the distance between the melting point and the atomizing point. The high-pressure inert gas ejected from the gas outlet can fully break up the molten metal, greatly improving the fine powder recovery rate. On the second hand, there is no need to modify the atomizing chamber (add an installation port for the induction coil), and the induction coil is normally installed from the upper smelting chamber, reducing the equipment processing cost. On the third hand, the airflow field is avoided from directly acting on the induction coil, and the powder making process is more stable. On the fourth hand, since the induction coil is not in the atomizing chamber of the atomizing nozzle, during the powder making process, the alloy powder produced is not easy to or even will not stick to the induction coil, protecting the use of the induction coil.

[0012] Preferably, the induction coil is symmetrically arranged along its axis.

[0013] In this solution, the above-mentioned structural form is adopted, and the electromagnetic induction intensity on each horizontal plane in the induction coil is the same, so the alloy base material is melted evenly; it is suitable for base materials such as rods, wires or thin rod raw materials, and has a wide range of applications.

[0014] Preferably, the induction coil comprises a conical unit, and a thin end of the conical unit is close to the bottom of the accommodating cavity.

[0015] In the present solution, the above-mentioned structural form is adopted, which makes it easy to control the melting stability of the base material, avoid the situation where the base material is induced to melt as a whole, the upper melt combines with the lower melt to make the melt larger, resulting in poor atomization effect and difficulty in controlling the atomization gas-liquid ratio; in addition, the melting point is at the lower part of the induction coil, which makes the melting point closer to the atomization point.

[0016] Preferably, the induction coil further comprises two connecting units connected to both sides of the conical unit, the conical unit comprises several layers of coil units arranged in parallel, the several layers of coil units are arranged from small to large according to diameter size, and the connecting units connect the several layers of coil units in sequence.

[0017] In this solution, the above-mentioned structural form is adopted to connect several layers of coil units through connecting units to enhance the compactness of the induction coil. Two connecting units are respectively arranged on both sides of the conical unit to ensure the symmetry and stability of the induction coil. In addition, since the electromagnetic induction intensity on each plane should be the same, the inner diameter of the conical unit gradually transitions from large to small, the magnetic field is relatively stable, the alloy base material melts stably, and the base material at the bottom of the induction coil gradually melts.

[0018] Preferably, there is a gap between the inner wall of the accommodating cavity and the connecting unit.

[0019] In the present solution, the above-mentioned structural form is adopted to reduce or avoid the thermal deformation of the accommodating chamber due to the influence of the induction coil; in addition, the inner wall of the accommodating chamber is far away from the induction coil, so that the heat converted by the induction coil acts more on the base material, thereby enhancing the melting effect of the base material and improving the recovery rate of fine alloy powder.

[0020] Preferably, the coil unit and the connecting unit are hollow inside, and the connecting unit is connected to several layers of the coil units.

[0021] In this solution, the above structure is adopted, and each layer of coil units is interconnected with two connecting units, so that a channel can be formed inside the induction coil. In the actual atomization process, cooling water is introduced into the connecting unit on one side, and the cooling water flows into all the coil units and flows out from the connecting unit on the other side to cool the induction coil to prevent it from softening during the heating process and protect the induction coil. It is also a kind of protection for the outside - it is conducive to reducing the temperature inside the device.

[0022] Preferably, the inner diameter of the accommodating cavity gradually transitions from large to small, wherein the closer to the bottom of the accommodating cavity, the smaller the inner diameter of the cavity.

[0023] In the present scheme, the above-mentioned structural form is adopted, the accommodating chamber is in a "funnel" structure, and the inner wall of the accommodating chamber is as far away from the induction coil as possible, so that the induction coil reduces the electromagnetic induction effect on the atomizing nozzle and acts more on the alloy base material, thereby enhancing the melting effect of the base material and improving the recovery rate of alloy fine powder.

[0024] Preferably, the gas ejection port is close to the bottom of the accommodating cavity;

[0025] And / or, the gas ejection outlet is arranged as an annular gap;

[0026] And / or, along the ejection direction of the gas, the opening of the gas ejection port first decreases and then increases.

[0027] In this solution, the above structure is adopted to shorten the distance between the melting point and the atomization point, thereby obtaining a higher alloy fine powder recovery rate. Inert gas can be sprayed from all sides of the melt to atomize the melt, with high atomization efficiency, greatly improving the powder production rate. Accelerating the gas spraying speed can fully break up the melt, greatly improving the fine powder recovery rate.

[0028] Preferably, a heat insulation layer is provided on the inner wall of the accommodating cavity.

[0029] In this solution, the above-mentioned structural form is adopted to avoid the atomizing nozzle from being deformed due to induction heat.

[0030] The present invention also provides an atomization system, which includes an atomization device and the device for preparing alloy powder by gas atomization as described above, wherein the atomization device is connected to the atomization nozzle.

[0031] The positive and progressive effects of the present invention are:

[0032] On the one hand, the induction coil is placed in the accommodating chamber, and the base material is placed in the induction coil for heating, that is, the melting point of the base material is in the accommodating chamber, that is, in the atomizing nozzle, but not above the atomizing nozzle, which shortens the distance between the melting point and the atomizing point. The high-pressure inert gas ejected from the gas outlet can fully break up the melt, greatly improving the fine powder recovery rate. On the other hand, there is no need to modify the atomizing chamber (add an installation port for the induction coil), and the induction coil is normally installed from the upper smelting chamber to reduce the equipment processing cost. On the third hand, the airflow field is avoided from directly acting on the induction coil, and the powder making process is more stable. On the fourth hand, since the induction coil is not in the atomizing chamber of the atomizing nozzle, the alloy powder produced is not easy to or will not stick to the induction coil during the powder making process, protecting the use of the induction coil. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 This is a schematic diagram of the structure of an apparatus for preparing alloy powder by gas atomization according to an embodiment of the present invention.

[0034] Figure 2 Schematic diagram of the structure of an atomizing nozzle according to an embodiment of the present invention.

[0035] Figure 3 Schematic diagram of the structure of the atomizing nozzle according to another embodiment of the present invention from another angle.

[0036] Figure 4 4 is a cross-sectional view of an atomizing nozzle according to an embodiment of the present invention.

[0037] Figure 5 Schematic diagram of the structure of the induction coil according to an embodiment of the present invention.

[0038] Figure 6 FIG. 4 is a schematic structural diagram of the induction coil according to another embodiment of the present invention from another angle.

[0039] Figure 7 FIG. 4 is a schematic structural diagram of the induction coil according to another embodiment of the present invention from another angle.

[0040] Figure 8 for Figure 1 A magnified view of the gas jet in the center.

[0041] Description of reference numerals:

[0042] Atomizing nozzle 1

[0043] Accommodating chamber 11

[0044] Gas outlet 12

[0045] The first outlet section 121

[0046] Second outlet section 122

[0047] The third outlet section 123

[0048] Insulation layer 13

[0049] Nozzle cavity 14

[0050] Induction coil 2

[0051] Conical unit 21

[0052] Coil unit 211

[0053] Connection unit 22

[0054] Extension unit 23 DETAILED DESCRIPTION

[0055] The present invention is further described below by way of examples, but the present invention is not limited to the scope of the examples.

[0056] The embodiment of the present invention provides a device for preparing alloy powder by gas atomization, such as Figure 1 , Figure 2 and Figure 3As shown. The device for preparing alloy powder by gas atomization includes an atomizing nozzle 1 and an induction coil 2. The atomizing nozzle 1 includes a receiving chamber 11, and the receiving chamber 11 is used to accommodate at least a part of the induction coil 2, wherein a through hole is provided in the atomizing nozzle 1 as the receiving chamber 11. The alloy parent material is placed in the induction coil 2, that is, in the receiving chamber 11 of the atomizing nozzle 1. The induction coil 2 heats the alloy parent material to melt it, and the molten liquid can fall directly from the bottom of the receiving chamber 11 without passing through the entire atomizing nozzle 1. The bottom of the atomizing nozzle 1 is also provided with an opening as a gas outlet 12, and the gas outlet 12 is oriented toward the axial direction of the induction coil 2. The high-pressure inert gas ejected from the gas outlet 12 crushes the falling molten liquid to harvest the alloy powder.

[0057] In this embodiment, on the one hand, the induction coil 2 is placed in the accommodating chamber 11, and the parent material is placed in the induction coil 2 for heating, that is, the melting point of the parent material is in the accommodating chamber 11, that is, in the atomizing nozzle 1, but not above the atomizing nozzle 1, which shortens the distance between the melting point and the atomizing point. The high-pressure inert gas ejected from the gas ejection port 12 can fully crush the melt, greatly improving the fine powder recovery rate. On the other hand, there is no need to modify the atomizing chamber (add an installation port for the induction coil), and the induction coil 2 is normally installed from the upper smelting chamber, reducing the equipment processing cost. On the third hand, the airflow field is avoided from directly acting on the induction coil 2, and the powder making process is more stable. On the fourth hand, since the induction coil is not in the atomizing chamber of the atomizing nozzle 1, during the powder making process, the alloy powder produced is not easy to or even will not stick to the induction coil 2, protecting the use of the induction coil 2.

[0058] As a preferred implementation, Figure 5 , Figure 6 and Figure 7 As shown, the induction coil 2 is symmetrically arranged along its axis. The traditional induction coil spirals upward, and the inlet and outlet are mostly one up and one down, with an asymmetric structure. The electromagnetic induction intensity on each horizontal plane should be different, requiring the rod-shaped parent material in the middle of the induction coil to rotate to eliminate the uneven melting. However, it is difficult to achieve rotation during the melting process for wire and thin rod raw materials. With this structural form, the electromagnetic induction intensity on each horizontal plane of the induction coil 2 is the same, and the alloy parent material is melted evenly; it is suitable for parent materials such as rods, wires or thin rod raw materials, and has a wide range of applications; and no other additional operations are required, and the operation is simple.

[0059] As a preferred implementation, Figure 1 and Figure 5As shown, the induction coil 2 includes a conical unit 21, and the thin end of the conical unit 21 is close to the bottom of the accommodating cavity 11. The inner diameter of the induction coil 2 increases from bottom to top. The upper part of the induction coil 2 is only induction preheated without melting because it is far from the parent material, and the lower part of the induction coil 2 is actually induction melting because it is close to the parent material. It is easy to control the stability of the melting of the parent material, and avoid the situation that the parent material is induction melted as a whole, the upper melt combines with the lower melt to make the melt larger, resulting in poor atomization effect and difficulty in controlling the atomization gas-liquid ratio; in addition, the melting point is at the lower part of the induction coil 2, so that the melting point is closer to the atomization point.

[0060] As a preferred embodiment, the induction coil 2 further includes two connecting units 22 connected to both sides of the conical unit 21. The conical unit 21 includes several layers of coil units 211 arranged in parallel. The several layers of coil units 211 are arranged from small to large according to the diameter size. The connecting units 22 connect the several layers of coil units 211 in sequence. The several layers of coil units 211 are connected by the connecting units 22 to enhance the compactness of the induction coil 2. The two connecting units 22 are respectively arranged on both sides of the conical unit 21 to ensure the symmetry and stability of the induction coil 2. In addition, since the electromagnetic induction intensity on each plane should be the same, the inner diameter of the conical unit 21 gradually transitions from large to small, the magnetic field is relatively stable, the alloy base material melts stably, and the base material at the bottom of the induction coil 2 gradually melts.

[0061] For example, the conical unit 21 uses 4-6 steel pipe rings of different horizontal planes and different diameters, the diameter of the steel pipe is 5mm-8mm, the wall thickness is 1mm-1.5mm, and the vertical spacing between each layer of steel pipe rings is 2mm-5mm. The connecting unit 22 uses a copper pipe, and the angle between the copper pipe of the connecting unit 22 and the central axis of the conical unit 21 is 20°-30°.

[0062] As a preferred embodiment, there is a gap between the inner wall of the accommodating chamber 11 and the connecting unit 22. This reduces or prevents the accommodating chamber 11 from being affected by the induction coil 2 and deformed by heat; in addition, the inner wall of the accommodating chamber 11 is far away from the induction coil 2, so that the heat converted by the induction coil 2 acts more on the parent material, enhancing the effect of melting the parent material, so as to improve the recovery rate of fine alloy powder.

[0063] As a preferred embodiment, the coil unit 211 and the connection unit 22 are hollow inside, and the connection unit 22 is connected to several layers of coil units 211. Each layer of coil units 211 is connected to two connection units 22, so that a channel can be formed inside the induction coil 2. Cooling water is introduced into the connection unit 22 on one side, flows into all the coil units 211, and flows out from the connection unit 22 on the other side to cool the induction coil 2 to prevent it from softening during the heating process and protect the induction coil 2. At the same time, it is also a protection for the outside - it is conducive to reducing the temperature inside the device.

[0064] As a preferred embodiment, the connection unit 22 is integrally formed with a plurality of coil units, which reduces the processing steps. In addition, the connection unit 22 can be connected with the coil unit 211, which is easier to achieve by integrally forming.

[0065] Specifically, a compact connection unit 22 and several coil units are formed in one piece by 3D printing. First, it is easy to achieve the connection between the connection unit 22 and the coil unit 211. Second, in the specific implementation, the inner diameter of the coil unit 211 with the smallest diameter in the conical unit 21 is set to 8mm-12mm, that is, the copper tube with a diameter of 5mm-8mm needs to be bent to an inner diameter ring of 8mm-12mm. Because if the inner diameter of the bottom coil unit 211 in the conical unit 21 is too large, the bottom opening of the cavity 11 of the accommodating cavity should also be increased accordingly, resulting in an increase in the distance between the gas ejection port 12 and the induction coil 2, that is, the distance between the melting point and the atomization point is lengthened; if the inner diameter is too small, the parent material is easy to stick to the induction coil 2 during the heating process, affecting the use effect of the induction coil 2. In addition to 3D printing, other conventional methods are difficult to achieve. The induction coil 2 also includes an extension unit 23 welded to the port of the connection unit 22, and the extension unit 23 is hollow to form a complete water flow channel. During the actual atomization process, cooling water is introduced into the extension unit 23 on one side, flows into all the coil units 211 and the connection unit 22 , and flows out from the extension unit 23 on the other side.

[0066] In addition, in a specific implementation, the induction coil 2 is made of CuCrZr copper alloy, and the melting efficiency of the base material is improved by taking advantage of its high electrical and thermal conductivity properties.

[0067] As a preferred implementation, Figure 1 and Figure 2 As shown, the inner diameter of the accommodating chamber 11 gradually transitions from large to small, wherein the closer to the bottom of the accommodating chamber 11, the smaller the inner diameter of the chamber. The accommodating chamber 11 is in a "bell mouth" structure, and the inner wall of the accommodating chamber 11 is as far away from the induction coil 2 as possible, so that the induction coil 2 reduces the electromagnetic induction effect on the atomizing nozzle 1, acts more on the alloy parent material, strengthens the effect of the parent material melting, and improves the recovery rate of alloy fine powder.

[0068] As a preferred implementation, Figure 1 and Figure 4 As shown, the angle between the inner wall of the accommodating cavity 11 and the bottom surface of the atomizing nozzle 1 is 45°-50°. If the angle is too large, the distance that the induction coil 2 extends into the accommodating cavity 11 is small, which lengthens the distance between the melting point and the atomizing point; if the angle is too large, the strength of the atomizing nozzle 1 cannot be guaranteed.

[0069] Specifically, the atomizing nozzle 1 is integrally formed by 3D printing. In order to ensure that the atomizing nozzle 1 does not need to add additional printing support during the printing process, the angle between the inner wall of the accommodating cavity 11 and the bottom surface of the atomizing nozzle 1 is 45°-50°. Figure 1 It is understood that the atomizing nozzle 1 includes a nozzle inner cavity 14 surrounding the accommodating cavity 11, and the cross section of the nozzle inner cavity 14 is triangular, in order to ensure that the atomizing nozzle 1 does not need to add additional printing support during the printing process, while reducing the printing raw materials and the printer. On the other hand, the traditional atomizing nozzle is machined with multiple parts, and then connected by sealing rings and fasteners such as bolts / screws between the parts, while the one-piece atomizing nozzle 1 does not include a sealing rubber ring, which simplifies the sealing ring and assembly structure inside the atomizing nozzle, and also avoids the situation where the sealing ring is damaged due to the excessive induction heating of the atomizing nozzle 1, resulting in the instability of the structure of the atomizing nozzle 1.

[0070] In addition, the atomizing nozzle 1 is made of CuCrZr copper alloy (printing performance reference: tensile strength 300±20MPa, yield strength 250±15MPa, elongation 38±2%), which is mainly based on the copper alloy's low electromagnetic induction heat generation. In addition, the copper alloy itself has a certain electromagnetic shielding effect and internal gas cooling, so the atomizing nozzle 1 does not need to consider water cooling.

[0071] The relevant dimensions of the atomizing nozzle 1 are as follows: the wall thickness is 3mm-8mm, the total thickness in the vertical direction is 50mm-70mm, the bottom diameter is 150mm-200mm, the bottom aperture of the accommodating chamber 11 is 20mm-25mm, and the inner wall of the accommodating chamber 11 is at an angle of 40°-45° with the central axis of the atomizing nozzle 1.

[0072] As a preferred embodiment, the gas ejection port 12 is close to the bottom of the accommodating chamber 11. The distance between the melting point and the atomization point is shortened to obtain a higher alloy fine powder yield.

[0073] Specifically, combined Figure 1 It is understood that the gas ejection port 12 is surrounded by several walls of the atomizing nozzle 1, and the gas ejection port 12 is closer to the melting point.

[0074] In some embodiments, the gas ejection port 12 is arranged as an annular seam. The gas ejection port 12 is axially arranged around the central axis of the accommodating chamber 11, and the inert gas can be ejected from all around the melt to atomize the melt, with high atomization efficiency, greatly improving the powder production rate.

[0075] In some embodiments, Figure 8 As shown, along the direction of gas ejection (such as Figure 8The opening of the gas outlet 12 is first reduced and then increased (indicated by the arrow in the middle). The inert gas is first compressed and then released in the gas outlet 12, which speeds up the gas ejection speed, can fully break up the melt, and greatly improve the fine powder recovery rate.

[0076] Specifically, the gas outlet 12 is a Laval structure, which includes a first outlet section 121, a second outlet section 122 and a third outlet section 123. The inert gas passes through the first outlet section 121 and the second outlet section 122 in sequence, and is ejected from the third outlet section 123 to atomize the melt. Among them, the inner diameter of the first outlet section 121 gradually shrinks from large to small to the middle to the second outlet section 122, and the inner diameter after the second outlet section 122 gradually expands from small to large as the third outlet section 123. The airflow is accelerated, and the ejected inert gas is more uniform, and the atomization effect is stable. In addition, the angle between the gas outlet 12 and the central axis of the atomizing nozzle 1 can be appropriately increased, for example, 45°-70°, to move the atomization point upward and shorten the distance between the melting point and the atomization point. The inner diameter at the end of the second outlet section 122 is set as the throat diameter, for example, the throat diameter is 0.5mm-1.2mm.

[0077] As a preferred embodiment, a heat insulating layer 13 is provided on the inner wall of the accommodating cavity 11 to avoid the atomizing nozzle 1 from being deformed due to induction heat.

[0078] In the specific implementation, the inner wall of the accommodating chamber 11 is treated with a "thermal barrier coating" surface, the coating thickness is 0.05mm-0.1mm, and the coating structure is: bonding layer (MCrAlY) + thermally grown oxide layer (Al2O3 film) + ceramic surface layer (Y2O3+ZrO2). It is mainly to avoid the deformation of the atomizing nozzle 1 due to thermal radiation during the high-temperature heating of the base material. This embodiment, as a schematic expression, adopts the method of applying a "thermal barrier coating" surface treatment to the inner wall of the accommodating chamber 11. In other alternative embodiments, any suitable method may also be adopted.

[0079] The embodiment of the present invention further provides an atomization system, which includes an atomization device and a device for preparing alloy powder by gas atomization according to any of the above embodiments, wherein the atomization device is connected to the atomization nozzle 1. The opening on the atomization nozzle 1 cooperates with the atomization device, and an inert gas is provided to the atomization nozzle 1 through the atomization device, and the inert gas is then ejected through the gas outlet 12 of the atomization nozzle 1. The opening can be arranged in an annular hole or an annular gap, that is, the opening is arranged axially around the central axis of the atomization nozzle 1. Of course, the shape of the opening is not limited, as long as the atomization device can cooperate with the atomization nozzle 1 through the opening.

[0080] In specific use, the atomizing nozzle 1 is installed on the atomizing device, and the induction coil 2 is installed from the window of the smelting chamber to the center of the accommodating chamber 11 by the mobile device, and a certain gap is maintained between the bottom of the induction coil 2 and the bottom of the accommodating chamber 11, for example, 2mm-15mm, and the bottom of the induction coil 2 is roughly parallel to the bottom of the accommodating chamber 11, and a certain gap is maintained between the bottom of the induction coil 2 and the inner wall of the accommodating chamber 11, for example, 1mm-5mm. The alloy parent material is sent to a specific position in the induction coil 2 by the feeding device, so that a certain distance is maintained between the bottom of the alloy parent material and the bottom of the accommodating chamber 11, for example, 5mm-25mm. Among them, the feeding speed needs to match the smelting amount and the atomization amount, so as to adjust the smelting amount per unit time during the smelting process, for example: the feeding speed is 10mm / s-30mm / s. The alloy parent material is made of wire with a diameter of 3mm-5mm, and of course, raw materials such as rods or thin rods can also be used. Cooling water is passed through the induction coil 2, and the power is turned on (for example: frequency 100k-250Hz, power 5kw-25kw). When the parent material is just melted, the atomizing equipment is turned on to spray out high-pressure inert gas (for example: air pressure is 2.5Mpa-4Mpa), and the high-pressure inert gas is sprayed out from the gas outlet 12, and the falling molten liquid is crushed at a certain position below the atomizing nozzle 1 to obtain alloy fine powder. Therefore, the powder making process has higher stability, and there is more room for improvement in power supply power, frequency, air pressure, gas flow, etc., and with process control, a higher alloy fine powder yield can be obtained.

[0081] The following two specific implementation methods are provided as examples:

[0082] Implementation Method 1

[0083] TC4 titanium alloy wire with a diameter of 3 mm was selected as the base material.

[0084] Atomizing nozzle 1 is made of CuCrZr copper alloy, and the dimensions are as follows:

[0085] 1) The bottom diameter of the atomizing nozzle 1 is 150 mm and the total thickness is 50 mm;

[0086] 2) The inner diameter of the center hole at the bottom of the accommodating cavity 11 is 20 mm;

[0087] 3) The angle between the side wall of the accommodating cavity 11 and the central axis is 45°;

[0088] 4) The wall thickness of the atomizing nozzle 1 is 3 mm, the angle between the inner cavity wall surface of the accommodating cavity 11 in the atomizing nozzle 1 and the central axis is also 45°, and the angle between the other inner cavity wall surfaces and the central axis is greater than 45°;

[0089] 5) The throat diameter is 0.7 mm, and the angle between the Laval tube structure and the central axis is 60°;

[0090] 6) The atomizing nozzle 1 is formed by SLM 3D printing integrated molding. The side wall of the accommodating cavity 11 is treated with a "thermal barrier coating" surface, and the structure and material of the thermal barrier coating are "bonding layer (MCrAlY) + thermally grown oxide layer (Al2O3 film) + ceramic surface layer (Y2O3 + ZrO2)".

[0091] The induction coil 2 is made of CuCrZr copper alloy, and the dimensions are as follows:

[0092] 1) The number of layers of the coil unit 211 is set to 5;

[0093] 2) The inner diameter of the bottom coil unit 211 is 8 mm;

[0094] 3) The diameter of the coil unit 211 is 5 mm and the wall thickness is 1 mm;

[0095] 4) The vertical spacing between adjacent coil units 211 is 3 mm;

[0096] 5) In any central axis section of the conical unit 21, there are two symmetrical oblique copper tubes as connecting units 22, the oblique copper tubes are connected to the five circles of horizontal copper tubes, and the angle between the oblique copper tubes and the central axis is 25°;

[0097] 6) The main part of the induction coil 2 (the conical unit 21 and the connecting unit 22) is integrally formed by SLM 3D printing, and the ports of the connecting unit 22 are respectively welded to the two extension units 23, wherein the extension units 23 use water-cooled copper tubes of the same specifications to form a complete water-cooled induction coil.

[0098] During specific use, the atomizing nozzle 1 is installed on the atomizing device, and the induction coil 2 is installed from the window of the smelting chamber to the center of the accommodating chamber 11 by the mobile device, and the gap between the bottom of the induction coil 2 and the bottom of the accommodating chamber 11 is maintained at 2mm. The wire is sent to a specific position in the induction coil 2 by the feeding device, and a distance of 5mm is retained between the bottom of the wire and the bottom of the accommodating chamber 11, and the feeding speed is adjusted to 25mm / s. Cooling water is passed into the induction coil 2, and the power is turned on (frequency 100k, power 5kw). When the wire is just melted, the atomizing equipment is turned on to spray high-pressure inert gas (air pressure is 2.5Mpa), and the high-pressure inert gas is sprayed from the gas outlet 12, and the falling molten liquid is broken at a certain position below the atomizing nozzle 1 to obtain fine alloy powder. A fine powder (≤53μm) ratio of more than 60% can be obtained.

[0099] Implementation Method 2

[0100] TC4 titanium alloy wire with a diameter of 4 mm was selected as the base material.

[0101] Atomizing nozzle 1 is made of CuCrZr copper alloy, and the dimensions are as follows:

[0102] 1) The bottom diameter of the atomizing nozzle 1 is 170 mm and the total thickness is 60 mm;

[0103] 2) The inner diameter of the center hole at the bottom of the accommodating chamber 11 is 22 mm;

[0104] 3) The angle between the side wall of the accommodating cavity 11 and the central axis is 45°;

[0105] 4) The wall thickness of the atomizing nozzle 1 is 3 mm, the angle between the inner cavity wall surface of the accommodating cavity 11 in the atomizing nozzle 1 and the central axis is also 45°, and the angle between the other inner cavity wall surfaces and the central axis is greater than 45°;

[0106] 5) The throat diameter is 0.9 mm, and the angle between the Laval tube structure and the central axis is 65°;

[0107] 6) The atomizing nozzle 1 is formed by SLM 3D printing integrated molding. The side wall of the accommodating cavity 11 is treated with a "thermal barrier coating" surface, and the structure and material of the thermal barrier coating are "bonding layer (MCrAlY) + thermally grown oxide layer (Al2O3 film) + ceramic surface layer (Y2O3 + ZrO2)".

[0108] The induction coil 2 is made of CuCrZr copper alloy, and the dimensions are as follows:

[0109] 1) The number of layers of the coil unit 211 is set to 5;

[0110] 2) The inner diameter of the bottom coil unit 211 is 10 mm;

[0111] 3) The diameter of the coil unit 211 is 5 mm and the wall thickness is 1 mm;

[0112] 4) The vertical spacing between adjacent coil units 211 is 3 mm;

[0113] 5) In any central axis section of the conical unit 21, there are two symmetrical oblique copper tubes as connecting units 22, the oblique copper tubes are connected to the five circles of horizontal copper tubes, and the angle between the oblique copper tubes and the central axis is 25°;

[0114] 6) The main part of the induction coil 2 (the conical unit 21 and the connecting unit 22) is integrally formed by SLM 3D printing, and the ports of the connecting unit 22 are respectively welded to the two extension units 23, wherein the extension units 23 use water-cooled copper tubes of the same specifications to form a complete water-cooled induction coil.

[0115] During specific use, the atomizing nozzle 1 is installed on the atomizing device, and the induction coil 2 is installed from the window of the smelting chamber to the center of the accommodating chamber 11 by the mobile device, and the gap between the bottom of the induction coil 2 and the bottom of the accommodating chamber 11 is maintained at 3mm. The wire is fed to a specific position in the induction coil 2 by the feeding device, and a distance of 10mm is retained between the bottom of the wire and the bottom of the accommodating chamber 11, and the feeding speed is adjusted to 15mm / s. Cooling water is passed into the induction coil 2, and the power is turned on (frequency 100k, power 10kw). When the wire is just melted, the atomizing equipment is turned on to spray high-pressure inert gas (air pressure is 3Mpa), and the high-pressure inert gas is sprayed from the gas outlet 12, and the falling molten liquid is broken at a certain position below the atomizing nozzle 1 to obtain fine alloy powder. A fine powder (≤53μm) ratio of more than 60% can be obtained.

[0116] Although the specific embodiments of the present invention are described above, it should be understood by those skilled in the art that this is only for illustration and the protection scope of the present invention is defined by the appended claims. Those skilled in the art may make various changes or modifications to these embodiments without departing from the principles and essence of the present invention, but these changes and modifications all fall within the protection scope of the present invention.

Claims

1. A device for preparing alloy powder by gas atomization, characterized in that: It comprises an atomizing nozzle and an induction coil, wherein the atomizing nozzle comprises a containing cavity, wherein the containing cavity is used to contain at least a part of the induction coil, and an opening is also provided at the bottom of the atomizing nozzle as a gas ejection port, and the gas ejection port faces the axial direction of the induction coil; The induction coil comprises a conical unit, and the thin end of the conical unit is close to the bottom of the accommodating cavity; The induction coil also includes two connecting units connected to both sides of the conical unit, the conical unit includes several layers of coil units arranged in parallel, the several layers of coil units are arranged from small to large according to diameter size, the connecting units connect the several layers of coil units in sequence, and the several layers of coil units and the connecting units are closed.

2. The device for preparing alloy powder by gas atomization according to claim 1, characterized in that: The induction coil is symmetrically arranged along its axis.

3. The device for preparing alloy powder by gas atomization according to claim 1, characterized in that: There is a gap between the inner wall of the accommodating cavity and the connecting unit.

4. The device for preparing alloy powder by gas atomization according to claim 1, characterized in that: The coil unit and the connection unit are hollow inside, and the connection unit is connected with several layers of the coil units.

5. The device for preparing alloy powder by gas atomization according to claim 1, characterized in that: The inner diameter of the accommodating cavity gradually transitions from large to small, wherein the closer to the bottom of the accommodating cavity, the smaller the inner diameter of the cavity.

6. The device for preparing alloy powder by gas atomization according to claim 1, characterized in that: The gas ejection port is close to the bottom of the accommodating cavity; And / or, the gas ejection outlet is arranged as an annular gap; And / or, along the ejection direction of the gas, the opening of the gas ejection port first decreases and then increases.

7. The device for preparing alloy powder by gas atomization according to claim 1, characterized in that: A heat insulation layer is arranged on the inner wall of the accommodating cavity.

8. An atomization system, characterized in that: The atomization system comprises an atomization device and the device for preparing alloy powder by gas atomization as claimed in any one of claims 1 to 7, and the atomization device is connected to the atomization nozzle.

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