Alloy powder vacuum gas atomization device for additive manufacturing

Abstract

In order to solve the problems of satellite powder defects, low powder yield and the like in the vacuum gas atomization process, the utility model provides an alloy powder vacuum gas atomization device for additive manufacturing, which comprises a smelting furnace and an atomization chamber connected to the lower part of the smelting furnace, the upper portion of the atomizing chamber is provided with an atomizing nozzle located on the outer side of the flow guide pipe, the atomizing nozzle is connected with a compressed inert gas tank, a heating device is arranged between the atomizing nozzle and the compressed inert gas tank, and the upper end in the atomizing chamber is further provided with an airflow whirling baffle located on the outer side of the atomizing nozzle. The length direction of the airflow rotation baffle is distributed in the vertical direction, the length of the airflow rotation baffle is adjustable, the temperature of inert gas in the atomizing nozzle is adjusted through the arranged heating device, the powder particle size and particle size distribution can be further reduced, and the powder yield is increased; and the airflow rotation baffle is arranged, so that airflow rotation in the atomizing chamber is inhibited, and the collision probability between the powder and the liquid drops is reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of additive manufacturing devices, in particular to an alloy powder vacuum gas atomization device used for additive manufacturing. Background Art

[0002] Vacuum gas atomization has become the mainstream technology for producing fine spherical metal and alloy powders. It is widely used in powder metallurgy, metal injection molding, metal additive manufacturing and other fields because it can produce powders with fine particle size, good sphericity, high purity and low oxygen content. The basic principle is to use high-speed airflow to impact the molten metal, and convert the kinetic energy of the gas into the surface energy of the molten metal through collision, so that the molten metal flow is broken into fine droplets, and then quickly cooled and solidified in the airflow atmosphere to form powder.

[0003] In the existing technology, for high-strength aluminum alloy powders used in 3D printing additive manufacturing, such as aluminum-based, copper-based, stainless steel-based, high-entropy alloy powders, etc., during the production process, the yield rate in the particle size range of 15~53μm is basically less than 40%. The main reasons for the above problems are the large width of the powder particle size distribution and satellite powder defects.

[0004] Satellite powder refers to a special form of powder particles formed in the process of atomization powder making. Specifically, it is an irregular particle formed by very small spherical particles adhering to larger spherical powder. For satellite powder, one theory holds that the solidified fine powder is sucked into the injection area under the nozzle by the swirling airflow and collides with the droplets that have not yet completely solidified, eventually forming satellite powder. Although reducing the diameter of the atomization chamber can effectively reduce the probability of satellite powder, it will cause the droplets to collide with the inner wall of the atomization chamber prematurely, reducing the powder yield.

[0005] Regarding powder particle size parameters, reducing the width of powder particle size distribution can not only increase the powder yield, which can effectively reduce the cost of powder production, but also reduce the width of particle size distribution can inhibit the formation of satellite powder, which is of great significance for improving the quality and performance of powder. Utility Model Content

[0006] In order to solve the problems of satellite powder defects and low powder yield in the vacuum gas atomization process, the utility model provides an alloy powder vacuum gas atomization device for additive manufacturing, and the technical solution adopted is as follows:

[0007] A vacuum air atomization device for alloy powder used in additive manufacturing, comprising a smelting furnace and an atomization chamber connected to the bottom of the smelting furnace, wherein a guide pipe is provided at the discharge port at the lower end of the smelting furnace, an atomization nozzle located outside the guide pipe is provided at the upper part of the atomization chamber, and the atomization nozzle is connected to a compressed inert gas tank. The device is characterized in that a heating device is provided between the atomization nozzle and the compressed inert gas tank, and an airflow swirl baffle is also provided at the upper end of the atomization chamber, the airflow swirl baffle is located outside the atomization nozzle, and the length direction of the airflow swirl baffle is distributed along the vertical direction and the length is adjustable.

[0008] Furthermore, the heating device includes a heating shell and a heating wire arranged inside the heating shell. The heating shell is provided with an air inlet and an air outlet respectively connected to the compressed inert gas tank and the atomizing nozzle.

[0009] Furthermore, the heating device is connected to a temperature regulating device, which includes a controller, a temperature sensor and a power regulating module. The power regulating module is connected to the heating wire, the temperature sensor is arranged between the heating device and the atomizing nozzle, and the temperature sensor is connected to the controller signal input end, and the power module is connected to the controller signal output end.

[0010] Furthermore, a height adjustment device is provided between the airflow swirl baffle and the atomization chamber, for adjusting the position of the airflow swirl baffle in the height direction of the flow field of the atomization nozzle.

[0011] Furthermore, the height adjustment device includes a baffle body, an adjustment plate, a drive motor and an adjustment screw. The adjustment plate is located on the baffle body and can be slidably connected to the inside of the baffle body along the length direction of the baffle body. The drive motor is arranged above the atomization chamber, and the drive motor is transmission-connected to the adjustment screw. The adjustment screw is threadedly connected to a nut, and the nut is fixedly connected to the adjustment plate.

[0012] Furthermore, a second baffle is arranged between the outer side of the airflow swirl baffle and the inner wall of the atomizing chamber, the inner end of the second baffle is fixedly connected to the lower end of the airflow swirl baffle, the outer end is connected to the inner wall of the atomizing chamber in an up and down sliding manner, and a vibration device is fixedly connected to the second baffle.

[0013] Furthermore, the vibration device is a mechanical vibrator or an ultrasonic generator.

[0014] Furthermore, the atomizing nozzle is a tightly coupled gas atomizing nozzle.

[0015] The beneficial effects of the utility model are:

[0016] 1. By setting a temperature regulating device between the atomizing nozzle and the inert gas compression tank, the temperature of the inert gas entering the atomizing nozzle can be adjusted according to different process parameters. Heating the inert gas temperature to a suitable temperature can further reduce the powder particle size and force distribution, effectively improving the powder yield;

[0017] 2. The airflow swirl baffle is set in the atomization chamber to suppress the airflow swirl generated inside the atomization chamber, reduce the collision probability between powder and droplets, thereby reducing the probability of satellite powder and further improving the powder recovery rate;

[0018] 3. The airflow swirl baffle is adjusted through the height adjustment device. The height adjustment can increase the airflow reflow space and reduce the reflow height without the need for complex operations such as disassembly and shutdown;

[0019] 4. By setting up the second baffle and the vibrator, the powder attached to the airflow vortex baffle and the second baffle can be vibrated and removed, thereby avoiding powder adhesion, further improving the powder recovery rate, and facilitating equipment cleaning. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 This is a schematic diagram of the structure of the utility model

[0021] Figure 2 for Figure 1 Schematic diagram of the partial enlarged structure of the middle A part

[0022] Figure 3 Schematic diagram of the connection structure between the baffle body and the adjustment plate

[0023] Among them, 1-smelting furnace, 2-stirring motor, 3-stirring rod, 4-feed hopper, 5-atomizing chamber, 6-driving motor, 7-baffle body, 8-adjusting plate, 9-screw, 10-nut, 11-second baffle, 12-vibrator, 13-atomizing nozzle, 14-guide pipe, 15-inert gas inlet, 16-inlet pipe, 17-temperature sensor, 18-heater, 19-controller, 20-power adjustment module, 21-inert gas compression tank, 22-inlet pipe of atomizing chamber, 23-powder collection tank. DETAILED DESCRIPTION

[0024] The exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although the exemplary embodiments of the present disclosure are shown in the accompanying drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided to enable a more thorough understanding of the present disclosure and to fully convey the scope of the present disclosure to those skilled in the art.

[0025] In the description of the utility model, it is necessary to understand that the terms "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the viewing direction or position relationship, and are only for the convenience of describing the utility model, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the utility model.

[0026] This embodiment provides an alloy powder vacuum gas atomization device for additive manufacturing, such as Figure 1-Figure 3 As shown, it includes a smelting furnace 1 and an atomizing chamber 5. An atomizing nozzle 13 is arranged on the upper part of the atomizing chamber 5. A temperature regulating device is arranged on the air inlet pipe 16 of the atomizing nozzle 13, which is used to regulate the temperature of the inert gas entering the atomizing nozzle 13. An airflow swirl baffle is also arranged at the upper position in the atomizing chamber 5. The airflow swirl baffle is located outside the airflow field of the atomizing nozzle 13, and the airflow swirl baffle is provided with a height regulating device.

[0027] Specifically, a stirring rod 3 is provided inside the smelting furnace 1, and a stirring motor 2 is provided at the upper end. The output shaft of the stirring motor 2 is transmission-connected to the stirring rod 3. The stirring motor 2 can drive the stirring rod 3 to rotate, thereby stirring the melt inside the smelting furnace 1. Of course, an ultrasonic generator or ultrasonic + mechanical stirring can also be used to mix the melt inside the smelting furnace 1 to improve the uniformity of the composite material inside the smelting furnace 1. A feed hopper 4 is also provided at the upper end of the smelting furnace 1, and a discharge port is provided at the lower end. A guide pipe 14 is connected below the discharge port.

[0028] An atomizing nozzle 13 is arranged above the atomizing chamber 5, and a powder collecting tank 23 is connected to the bottom thereof. An atomizing chamber air inlet pipe 22 is also connected between the inert gas compression tank 21 and the atomizing chamber 5. In this embodiment, the atomizing nozzle 13 adopts a tightly coupled atomizing nozzle, such as Figure 2As shown, the atomizing nozzle 13 is fixedly connected to the lower end of the smelting furnace 1, the guide pipe 14 extends downward into the guide channel on the main body of the atomizing nozzle 13, the inert gas inlet 15 of the atomizing nozzle 13 is connected to the inert gas compression tank 21 through the air inlet pipe 16, the temperature regulating device includes a heater 18, a temperature sensor 17, a controller 19 and a power regulating module 20, the heater 18 is composed of a heating shell and a heating wire, the heating shell is a hollow and sealed shell structure, a plurality of groups of heating wires are arranged inside the heating shell, and an air inlet and an air outlet are respectively arranged on both sides of the heating shell, the air inlet and the inert gas compression tank 21 are connected to each other through the air inlet pipe 16, and the temperature regulating device includes a heater 18, a temperature sensor 17, a controller 19 and a power regulating module 20, the heater 18 is composed of a heating shell and a heating wire, the heating shell is an internally hollow and sealed shell structure, a plurality of groups of heating wires are arranged inside the heating shell, and an air inlet and an air outlet are respectively arranged on both sides of the heating shell, and the air inlet and the inert gas compression tank 21 are connected to each other through the air inlet pipe 16. The inert gas compression tank 21 is connected, and the air outlet is connected to the atomizing nozzle 13 through the air inlet pipe 16; the temperature sensor 17 is arranged on the air inlet pipe 16 at the air outlet of the heating shell, and the power regulation module 20 adopts a thyristor voltage regulation module. The temperature sensor 17 and the power regulation module 20 are respectively connected to the signal input end and the signal output end of the controller 19. The controller 19 controls the heating temperature of the heater 18 through the power regulation module 20, and monitors the inert gas temperature on the air inlet pipe 16 through the temperature sensor 17 for feedback, so as to ensure that the inert gas temperature in the atomizing nozzle 13 meets the process setting requirements.

[0029] The inert gas is heated by the heater 18, and feedback adjustment is performed by the controller 19, the power adjustment module 20 and the temperature sensor 17, which is suitable for process adjustment under different production environments.

[0030] In this embodiment, taking aluminum-based alloy powder as an example, the feedback temperature of the temperature sensor 17 is controlled at 300-350°C. At this temperature, the increase in temperature not only enhances the atomization effect and increases the kinetic energy of the inert gas to make the obtained particle size more uniform and finer, but also reduces the density of the inert gas and improves fluidity, which helps to mix the gas and liquid more evenly, thereby improving the uniformity of the atomization process and reducing the production of large or irregular particles, thereby further reducing the powder particle size and particle size distribution, which can effectively improve the powder yield; at the same time, it can also avoid the problem of increased particle size and uneven distribution caused by excessively high temperature leading to excessive diffusion of airflow.

[0031] The airflow swirl baffle includes a baffle body 7 and an adjustment plate 8. The baffle body 7 is a plate-like structure distributed in the vertical direction as a whole, and a slide groove distributed in the vertical direction and penetrating downward is arranged inside the baffle body 7. The upper end of the baffle body 7 is fixedly connected to the upper end cover of the atomization chamber 5 and is located outside the atomization nozzle 13. The adjustment plate 8 is connected to the inside of the slide groove by sliding up and down.

[0032] The height adjustment device includes a driving motor 6, a lead screw 9 and a nut 10. The lead screw 9 is distributed in a vertical direction, and the upper part is rotatably connected to the inside of the baffle body 7 through a bearing. The nut 10 is threadedly connected to the lead screw 9 and fixedly connected to the adjustment plate 8. The driving motor 6 is fixedly connected above the atomization chamber 5 and is located on one side of the smelting furnace 1. The output shaft of the driving motor 6 is distributed vertically upward, and the upper end of the lead screw 9 extends upward from the atomization chamber 5 by a certain length, and the lead screw 9 is connected to the output shaft of the driving motor 6 through a gear set meshing transmission. The driving motor 6 is actuated to drive the lead screw 9 to rotate, thereby driving the adjustment plate 8 to slide up and down along the baffle body 7 through the nut 10, thereby realizing the adjustment of the airflow swirl baffle height.

[0033] The setting of the air flow swirl baffle can block the swirl of the air flow sprayed from the atomizing nozzle 13, inhibit the swirl of the air flow in the atomizing chamber, and thus reduce the probability of collision between powder and droplets; by adjusting the height of the air flow swirl baffle, the air flow reflow space is increased and the reflow height is reduced, which can be suitable for the production of alloy powders under different process parameters such as atomizing nozzle flow rate and flow rate, and the height is automatically adjusted by the driving motor 6, and the equipment does not need to be shut down or dismantled for complex operations.

[0034] In addition, a second baffle plate 11 is fixedly connected to the lower end of the adjusting plate 8, an inner end of the second baffle plate 11 is fixedly connected to the lower end of the adjusting plate 8, and an outer end of the second baffle plate 11 is connected to the inner wall of the atomizing chamber 5 for sliding up and down. In order to improve the coordination stability between the two, a groove is provided at the outer end of the second baffle plate 11, and a boss connected to the inner wall of the atomizing chamber 5 for sliding up and down in cooperation with the groove is provided. A vibrator 12 is also fixedly connected to the second baffle plate 11. By setting the vibrator 12 to vibrate the second baffle plate 11, the baffle body 7 and the adjusting plate 8 are driven to vibrate at the same time, so that the powder attached to the surface falls off, which is convenient for cleaning the baffle and avoids the adhesion of the powder and the reduction of the yield.

[0035] This device is not only suitable for aluminum-based alloy powders, but also for the vacuum gas atomization production of copper-based, stainless steel-based, high-entropy alloy and other powders. It can effectively reduce the width of powder particle size distribution and the appearance of satellite powder, thereby improving the powder recovery rate.

[0036] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements can be made without departing from the principle of the present invention, and these improvements should also be regarded as the protection scope of the present invention.

Claims

1. A vacuum gas atomization device for alloy powder for additive manufacturing, comprising a smelting furnace, an atomization chamber connected to the bottom of the smelting furnace, a guide pipe is provided at the discharge port at the lower end of the smelting furnace, an atomization nozzle located outside the guide pipe is provided at the upper part of the atomization chamber, and the atomization nozzle is connected to a compressed inert gas tank, characterized in that: A heating device is provided between the atomizing nozzle and the compressed inert gas tank. An airflow swirl baffle is also provided at the upper end of the atomizing chamber. The airflow swirl baffle is located outside the atomizing nozzle. The length direction of the airflow swirl baffle is distributed along the vertical direction and the length is adjustable.

2. The alloy powder vacuum gas atomization device for additive manufacturing according to claim 1, characterized in that: The heating device comprises a heating shell and a heating wire arranged inside the heating shell. The heating shell is provided with an air inlet and an air outlet which are respectively connected to a compressed inert gas tank and an atomizing nozzle.

3. The alloy powder vacuum gas atomization device for additive manufacturing according to claim 2, characterized in that: The heating device is connected to a temperature regulating device, which includes a controller, a temperature sensor and a power regulating module. The power regulating module is connected to the heating wire, the temperature sensor is arranged between the heating device and the atomizing nozzle, and the temperature sensor is connected to the controller signal input end, and the power module is connected to the controller signal output end.

4. The alloy powder vacuum gas atomization device for additive manufacturing according to claim 1, characterized in that: A height adjustment device is provided between the airflow swirling baffle and the atomization chamber, and is used to adjust the position of the airflow swirling baffle in the height direction.

5. The alloy powder vacuum gas atomization device for additive manufacturing according to claim 4, characterized in that: The height adjustment device includes a baffle body, an adjustment plate, a drive motor and an adjustment screw. The adjustment plate is located on the baffle body and can be slidably connected to the inside of the baffle body along the length direction of the baffle body. The drive motor is arranged above the atomization chamber. The drive motor is connected to the adjustment screw by transmission. The adjustment screw is threadedly connected with a nut from above, and the nut is fixedly connected to the adjustment plate.

6. The alloy powder vacuum gas atomization device for additive manufacturing according to claim 4 or 5, characterized in that: A second baffle is arranged between the outer side of the airflow swirl baffle and the inner wall of the atomizing chamber, the inner end of the second baffle is fixedly connected to the lower end of the airflow swirl baffle, and the outer end is connected to the inner wall of the atomizing chamber in an up and down sliding manner, and a vibration device is fixedly connected to the second baffle.

7. The alloy powder vacuum gas atomization device for additive manufacturing according to claim 6, characterized in that: The vibration device is a mechanical vibrator or an ultrasonic generator.

8. The alloy powder vacuum gas atomization device for additive manufacturing according to claim 1, characterized in that: The atomizing nozzle is a tightly coupled gas atomizing nozzle.

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