Device and method for preparing ceramic-nickel-based composite powder for 3D printing

Abstract

The invention provides a preparation device and method of ceramic-nickel-based composite powder for 3D printing, and belongs to the technical field of preparation of ceramic-nickel-based spherical composite powder for 3D printing. According to the preparation device of the ceramic-nickel-based composite powder for 3D printing, an air storage tank is connected with a ceramic micro-powder storage tank through a low-pressure air conveying pipeline, a heating leaking ladle is located below a smelting furnace, and molten metal heated by the smelting furnace enters the heating leaking ladle; the ceramic micro-powder storage tank is connected with an upper-stage low-pressure nozzle through a powder mixing pipeline, and the gas storage tank is connected with a lower-stage high-pressure nozzle through a high-pressure gas conveying pipeline; the upper-stage low-pressure nozzle and the lower-stage high-pressure nozzle are both connected with the flow guide channel. An annular argon spray pipe is arranged at the upper part of the atomization tank; and a rotary secondary crushing disc is arranged right below a feeding port of the atomization tank. The technological process for preparing the ceramic-nickel-based spherical composite powder through the device can achieve automation, performance is stable and reliable, and the device is suitable for large-scale production of high-performance composite powder for 3D printing.

Description

Technical Field

[0001] The invention provides a device and a method for preparing ceramic-nickel-based composite powder for 3D printing, belonging to the technical field of preparing ceramic-nickel-based spherical composite powder for 3D printing. Background Art

[0002] With the rapid development of high-end equipment in the fields of aerospace, military and national defense, higher and higher requirements have been put forward for the strong load-bearing, high heat resistance, wear resistance, corrosion resistance, lightweight and integrated design and manufacturing of complex structures of hot-end parts serving in extremely harsh environments. Compared with nickel-based high-temperature alloys, one of the typical representative materials for traditional hot-end parts manufacturing, ceramic particle reinforced nickel-based composite materials developed in recent years have a wide range of demands in the field of high-end equipment due to their higher specific strength, specific stiffness, heat resistance, corrosion resistance, oxidation resistance and other comprehensive properties.

[0003] The preparation of ceramic particle reinforced nickel-based composites using traditional processes (such as in-situ reaction, casting, melt infiltration, self-propagating high-temperature synthesis and powder metallurgy) usually requires special precision forming molds, complex processes, low density of formed parts, uneven structure, difficulty in producing complex structural shapes, and the need for subsequent surface processing. The manufacturing is difficult, the cycle is long, and the cost is high, which can no longer meet the urgent needs of high-performance complex components in the harsh service environment of high-end fields such as aerospace.

[0004] In the additive manufacturing industry chain of high-performance complex metal alloys and their composite structural parts, high-quality powder raw materials are the material basis and forerunner of the development of this technology, playing a vital role and directly affecting the quality and performance of the formed parts. However, since the research on metal alloys and composite powder materials for additive manufacturing in my country is still in its infancy, high-end powders rely on imports and are severely restricted; core powder making technology and equipment cannot be introduced (international blockade and embargo), and independent research and development investment is insufficient; the high cost of powder material preparation and unstable quality seriously affect the promotion and application of ceramic particle reinforced nickel-based composite materials in the field of high-end equipment, and have become a bottleneck problem that needs to be solved urgently. Summary of the invention

[0005] The purpose of the present invention is to overcome the deficiencies in the prior art and to provide a device and method for preparing ceramic-nickel-based composite powder for 3D printing. The process of preparing ceramic-nickel-based spherical composite powder by the device can be automated, and the performance is stable and reliable, which is suitable for large-scale production of high-performance composite powder for 3D printing.

[0006] In order to solve the problems of the prior art, the present invention discloses a device for preparing ceramic-nickel-based composite powder for 3D printing, comprising a ceramic micropowder storage tank, a smelting tank and an atomizing tank. A powder feeding ultrasonic device is arranged at the bottom of the ceramic micropowder storage tank, and the gas storage tank is connected to the ceramic micropowder storage tank through a low-pressure gas pipeline.

[0007] The smelting tank includes a smelting furnace and a heating leak bag, the heating leak bag is located below the smelting furnace, and the molten metal heated by the smelting furnace enters the heating leak bag; the ceramic micropowder storage tank is connected to the upper low-pressure nozzle below the heating leak bag through a powder mixing pipeline, and the gas storage tank is connected to the lower high-pressure nozzle below the heating leak bag through a high-pressure gas transmission pipeline; the bottom opening of the smelting tank is connected to the feeding port at the top of the atomization tank, and the channel from the bottom of the heating leak bag to the bottom opening position of the smelting tank forms a diversion channel, and the upper low-pressure nozzle and the lower high-pressure nozzle are both connected to the diversion channel.

[0008] An annular argon nozzle is arranged on the upper part of the atomizing tank, a rotating secondary crushing disk is arranged just below the feeding port of the atomizing tank, and a discharge port is arranged at the bottom of the atomizing tank.

[0009] Preferably, a circulating cooling water pipe is also provided at the lower part of the atomizing tank.

[0010] Preferably, the atomizing tank is also provided with a vacuum pumping device.

[0011] Preferably, a dust removal device is also provided on the atomizing tank.

[0012] Preferably, pressure gauges are provided on the low-pressure gas pipeline and the high-pressure gas pipeline.

[0013] Preferably, a pressure regulating valve is provided on the pipeline between the low-pressure gas pipeline and the ceramic micropowder storage tank.

[0014] Preferably, a smelting ultrasonic device is provided below the upper low-pressure nozzle.

[0015] The present invention also discloses a method for preparing a ceramic-nickel-based composite powder for 3D printing, which specifically includes: (1) loading a set amount of ceramic powder into a ceramic powder storage tank and loading a set amount of nickel matrix into a smelting furnace; (2) opening a gas storage tank connected to a low-pressure gas pipeline and a high-pressure gas pipeline, and adjusting the pressure gauges on the low-pressure gas pipeline and the high-pressure gas pipeline so that the gas flow reaches a specified pressure; (3) starting the ceramic powder storage tank and the powder feeding ultrasonic device below, and controlling the powder feeding speed according to the process requirements; (4) smelting furnace The molten metal in the atomizer is poured into the heating ladle and mixed with the ceramic powder-argon mixture sprayed from the upper low-pressure nozzle and the argon sprayed from the lower high-pressure nozzle in the guide channel and atomized to form composite droplets; (5) In the atomizer, the broken composite droplets are rapidly cooled and solidified through the annular argon nozzle, the circulating cooling water pipe and the rotating secondary crushing disk to form high-performance ceramic-nickel-based spherical composite powder; (6) The ceramic-nickel-based spherical composite powder is discharged from the discharge port at the bottom of the atomizer and is dried, screened and packaged to obtain the finished product.

[0016] The beneficial effects of the present invention are: (1) The ceramic micropowder is dispersed and transported by a powder mixing device composed of a ceramic micropowder storage tank and a powder feeding ultrasonic device below through the coordination of ultrasonic vibration and air flow disturbance. The powder feeding ultrasonic device at the bottom of the ceramic micropowder storage tank generates ultrasonic impact when vibrating at ultrasonic frequency and the disturbance of low-pressure airflow to prevent the blockage of the micropowder outlet, so that the micropowder is well dispersed; at the same time, there is a certain pressure difference between the upper and lower parts of the ceramic micropowder storage tank. Under the action of pressure, the ceramic micropowder enters the powder mixing pipeline through the powder outlet of the ceramic micropowder storage tank. The powder feeding ratio can be controlled by controlling the speed of the stepper motor.

[0017] (2) A two-stage atomizing nozzle is used to atomize the metal liquid flow. The upper low-pressure nozzle adopts an ultrasonic low-pressure tightly coupled annular gap nozzle, and the lower high-pressure nozzle adopts a high-pressure supersonic nozzle. The upper low-pressure nozzle has a low injection speed of low-pressure airflow mixed with ceramic micropowder, which causes less wear on the nozzle. Compared with the single-stage atomizing nozzle, the experiment will not be unable to be carried out due to rapid wear due to high pressure. The lower high-pressure nozzle sprays high-pressure pure inert gas, which will not cause wear on the nozzle.

[0018] (3) An annular argon nozzle is used to spray inert gas argon to cool and solidify the broken droplets, increasing the rotation of the droplets on the secondary crushing disk. The cooling rate can be precisely controlled by controlling the annular argon injection speed and flow rate, thereby preparing the ceramic-nickel-based spherical composite powder required under different conditions.

[0019] (4) The process for preparing ceramic-nickel-based spherical composite powders can be automated, with stable and reliable performance, and is suitable for large-scale production of composite powders for high-performance 3D printing. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a schematic diagram of the structure of the present invention; Figure 2 It is a schematic diagram of the structure of the atomization and cooling device in the present invention.

[0021] Reference numerals: 1. Discharge port; 2. Circulating cooling water pipe; 3. Vacuum pumping device; 4. Atomizing tank; 5. Annular argon nozzle; 6. Smelting tank; 7. Smelting furnace; 8. Powder mixing pipeline; 9. Ceramic micro powder storage tank; 10. Ceramic micro powder; 11. Powder feeding ultrasonic device; 12. Pressure regulating valve; 13. Pressure gauge; 14. Low-pressure gas pipeline; 15. Heating leakage bag; 16. Upper low-pressure nozzle; 17. Smelting ultrasonic device; 18. Lower high-pressure nozzle; 19. Diversion channel; 20. Rotating secondary crushing disk; 21. Gas storage tank; 22. High-pressure gas pipeline; 23. Dust removal device. DETAILED DESCRIPTION

[0022] The present invention will be further described below in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the structure of the present invention.

[0023] like Figure 1 and Figure 2 As shown, a device for preparing ceramic-nickel-based composite powder for 3D printing includes a ceramic micropowder storage tank 9, a smelting tank 6 and an atomizing tank 4. A powder feeding ultrasonic device 11 is provided at the bottom of the ceramic micropowder storage tank 9, and the gas storage tank 21 is connected to the ceramic micropowder storage tank 9 through a low-pressure gas pipeline 14.

[0024] The smelting tank 6 includes a smelting furnace 7 and a heating leaking bag 15, the heating leaking bag 15 is located below the smelting furnace 7, and the molten metal heated by the smelting furnace 7 enters the heating leaking bag 15; the ceramic powder storage tank 9 is connected to the upper low-pressure nozzle 16 below the heating leaking bag 15 through the powder mixing pipeline 8, and the gas storage tank 21 is connected to the lower high-pressure nozzle 18 below the heating leaking bag 15 through the high-pressure gas pipeline 22; the bottom opening of the smelting tank 6 is connected to the feeding port at the top of the atomizing tank 4, and the channel from the bottom of the heating leaking bag 15 to the bottom opening position of the smelting tank 6 forms a diversion channel 19, and the upper low-pressure nozzle 16 and the lower high-pressure nozzle 18 are both connected to the diversion channel 19.

[0025] Pressure gauges 13 are provided on the low-pressure gas pipeline 14 and the high-pressure gas pipeline 22 , a pressure regulating valve 12 is provided on the pipeline between the low-pressure gas pipeline 14 and the ceramic powder storage tank 9 , and a smelting ultrasonic device 17 is provided below the upper low-pressure nozzle 16 .

[0026] An annular argon nozzle 5 is provided on the upper part of the atomizing tank 4 , a rotating secondary crushing disk 20 is provided just below the feeding port of the atomizing tank 4 , and a discharge port 1 is provided at the bottom of the atomizing tank 4 .

[0027] A circulating cooling water pipe 2 is also provided at the lower part of the atomizing tank 4 , a vacuum pumping device 3 is also provided on the atomizing tank 4 , and a dust removal device 23 is also provided on the atomizing tank 4 .

[0028] In actual production, the smelting furnace 7 may adopt a "medium frequency induction furnace".

[0029] In the present invention, the ceramic powder 10 is dispersed and transported in coordination through ultrasonic vibration-airflow disturbance, and a two-stage atomizing nozzle is used to atomize the molten metal flow. The upper low-pressure nozzle 16 adopts an ultrasonic low-pressure tightly coupled annular gap nozzle, and the lower high-pressure nozzle 18 adopts a high-pressure supersonic nozzle. The upper low-pressure nozzle 16 is close to the lower high-pressure nozzle 18. The upper low-pressure nozzle 16 sprays a low-pressure inert gas mixed powder jet containing uniform ceramic powder, and the lower high-pressure nozzle 18 sprays a high-pressure inert pure gas atomizing jet. The molten metal flows from the heating leak bag 15 into the guide channel 19 according to its own gravity, and then flows to the atomization focus of the upper low-pressure nozzle 16. The low-pressure inert gas is uniformly sprayed through the upper low-pressure nozzle 16 and injected into the molten metal flow. The molten metal flow mixed with ceramic powder continues It flows into the atomization focus of the lower-stage high-pressure nozzle 18, and the supersonic high-pressure atomizing gas ejected by the lower-stage high-pressure nozzle 18 is atomized into tiny droplets, which are rapidly solidified into a composite spherical powder containing ceramic particles through cooling devices such as the annular argon nozzle 5, the circulating cooling water pipe 2, and the rotating secondary crushing disk 20; by controlling process parameters such as the matrix component ratio, ultrasonic amplitude, atomization pressure, and cooling rate, a ceramic-nickel-based spherical composite powder with high density, uniform structure, and uniform and dense distribution of ceramic powder inside and outside the matrix is ​​formed.

[0030] Example 1: According to the device shown in the figure, the method for preparing TiC-nickel-based spherical composite powder comprises the following steps: (1) Loading a set amount of TiC ceramic powder 10 into a ceramic powder storage tank 9; (2) heating a predetermined amount of nickel matrix in a smelting furnace 7 to a molten state and reaching a predetermined superheat; (3) Open the gas storage tank 21 connected to the low-pressure gas pipeline 14 and the high-pressure gas pipeline 22, and adjust the pressure gauges 13 on the low-pressure gas pipeline 14 and the high-pressure gas pipeline 22 so that the gas flow reaches the specified pressure; (4) Start the ceramic powder storage tank 9 and the powder feeding ultrasonic device 11 below, and control the powder feeding speed according to the process requirements; (5) The molten metal in the smelting furnace 7 is poured into the heating ladle 15, and is mixed and atomized with the ceramic powder-argon mixture sprayed from the upper low-pressure nozzle 16 and the argon sprayed from the lower high-pressure nozzle 18 in the guide channel to form composite droplets; (6) In the atomizing tank 4, the crushed composite droplets are rapidly cooled and solidified through the annular argon nozzle 5, the circulating cooling water pipe 2 and the rotating secondary crushing disk 20 to form a high-performance TiC-nickel-based spherical composite powder; 7) The obtained TiC-nickel-based spherical composite powder is dried, sieved and packaged to obtain composite powders for 3D printing with different particle sizes.

[0031] Example 2: According to the device shown in the figure, the method for preparing Al2O3-nickel-based spherical composite powder includes the following steps: (1) A set amount of Al2O3 ceramic powder 10 is loaded into a ceramic powder storage tank 9; (2) heating a predetermined amount of nickel matrix in a smelting furnace 7 to a molten state and reaching a predetermined superheat; (3) Open the gas storage tank 21 connected to the low-pressure gas pipeline 14 and the high-pressure gas pipeline 22, and adjust the pressure gauges 13 on the low-pressure gas pipeline 14 and the high-pressure gas pipeline 22 so that the gas flow reaches the specified pressure; (4) Start the ceramic powder storage tank 9 and the powder feeding ultrasonic device 11 below, and control the powder feeding speed according to the process requirements; (5) The molten metal in the smelting furnace 7 is poured into the heating ladle 15, and is mixed and atomized with the ceramic powder-argon mixture sprayed from the upper low-pressure nozzle 16 and the argon sprayed from the lower high-pressure nozzle 18 in the guide channel to form composite droplets; (6) In the atomizing tank 4, the crushed composite droplets are rapidly cooled and solidified through the annular argon nozzle 5, the circulating cooling water pipe 2 and the rotating secondary crushing disk 20 to form a high-performance Al2O3-nickel-based spherical composite powder; 7) The obtained Al2O3-nickel-based spherical composite powder is dried, sieved and packaged to obtain composite powders for 3D printing with different particle sizes.

[0032] Example 3: A certain amount of WC ceramic powder 10 is loaded into a ceramic powder storage tank 9, and the steps of Examples 1 and 2 are followed to obtain WC-nickel-based spherical composite powder.

[0033] Example 4: A certain amount of SiC ceramic powder 10 is loaded into a ceramic powder storage tank 9, and the steps of Examples 1 and 2 are followed to obtain SiC-nickel-based spherical composite powder.

[0034] In the present invention, an annular argon nozzle is used to spray inert gas argon to cool and solidify the broken droplets. A droplet rotating secondary crushing disk 20 is added at 0.6m in the atomizing tank 4 in the coaxial direction with the heating leak bag 15 and the atomizing nozzle. The cooling rate can be controlled by controlling the annular argon injection speed and flow rate.

[0035] 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 and modifications can be made without departing from the technical principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A device for preparing ceramic-nickel-based composite powder for 3D printing, characterized in that: Including ceramic micro powder storage tanks, gas storage tanks, smelting tanks and atomizing tanks, A powder feeding ultrasonic device is provided at the bottom of the ceramic micro-powder storage tank, and the gas storage tank is connected to the ceramic micro-powder storage tank through a low-pressure gas pipeline; The smelting tank includes a smelting furnace and a heating ladle, the heating ladle is located below the smelting furnace, and the molten metal heated by the smelting furnace enters the heating ladle; the ceramic powder storage tank is connected to the upper low-pressure nozzle below the heating ladle through a powder mixing pipeline, and the gas storage tank is connected to the lower high-pressure nozzle below the heating ladle through a high-pressure gas pipeline; the bottom opening of the smelting tank is connected to the feeding port at the top of the atomizing tank, and the channel from the bottom of the heating ladle to the bottom opening of the smelting tank forms a diversion channel, and the upper low-pressure nozzle and the lower high-pressure nozzle are both connected to the diversion channel; An annular argon nozzle is arranged on the upper part of the atomizing tank, a rotating secondary crushing disk is arranged just below the feeding port of the atomizing tank, and a discharge port is arranged at the bottom of the atomizing tank.

2. The device for preparing a ceramic-nickel-based composite powder for 3D printing according to claim 1, characterized in that: A circulating cooling water pipe is also arranged at the lower part of the atomizing tank.

3. The device for preparing a ceramic-nickel-based composite powder for 3D printing according to claim 1, characterized in that: The atomizing tank is also provided with a vacuum pumping device.

4. A device for preparing ceramic-nickel-based composite powder for 3D printing according to claim 2 or 3, characterized in that: The atomizing tank is also provided with a dust removal device.

5. The device for preparing a ceramic-nickel-based composite powder for 3D printing according to claim 1, characterized in that: The low-pressure gas pipeline and the high-pressure gas pipeline are provided with pressure gauges.

6. The device for preparing a ceramic-nickel-based composite powder for 3D printing according to claim 5, characterized in that: A pressure regulating valve is arranged on the pipeline between the low-pressure gas pipeline and the ceramic micro-powder storage tank.

7. The device for preparing a ceramic-nickel-based composite powder for 3D printing according to claim 1, characterized in that: A smelting ultrasonic device is arranged below the upper low-pressure nozzle.

8. A method for preparing a ceramic-nickel-based composite powder for 3D printing using the device for preparing a ceramic-nickel-based composite powder for 3D printing according to any one of claims 1 to 7, characterized in that: The following steps are involved: (1) Loading a set amount of ceramic powder into a ceramic powder storage tank and a set amount of nickel matrix into a smelting furnace; (2) Open the gas storage tank connected to the low-pressure gas pipeline and the high-pressure gas pipeline, and adjust the pressure gauges on the low-pressure gas pipeline and the high-pressure gas pipeline so that the gas flow reaches the specified pressure; (3) Start the ceramic micro powder storage tank and the powder feeding ultrasonic device below, and control the powder feeding speed according to the process requirements; (4) The molten metal in the smelting furnace is poured into the heating ladle and mixed and atomized with the ceramic powder-argon mixture sprayed from the upper low-pressure nozzle and the argon gas sprayed from the lower high-pressure nozzle in the guide channel to form composite droplets; (5) In the atomization tank, the broken composite droplets are rapidly cooled and solidified through the annular argon nozzle, circulating cooling water pipe and rotating secondary crushing disk to form high-performance ceramic-nickel-based spherical composite powder; (6) The ceramic-nickel-based spherical composite powder is discharged from the discharge port at the bottom of the atomizing tank, and is dried, sieved and packaged to obtain a finished product.

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