An apparatus, method and system for preparing spherical composite powder

Abstract

The present invention provides an apparatus, a method and a system for preparing spherical composite powder. The apparatus includes a spheroidizing generator and an air supply device; the spheroidizing generator includes a housing having a cavity therein; a spray gun is provided at the top of the housing; the outlet of the spray gun is located within the cavity, and the inlet of the spray gun is connected to a slurry preparation container through a slurry pipe; the air outlet of the air supply device is communicated with the bottom opening of the housing, so that the gas sent into the cavity by the air supply device can blow the raw material powder in the cavity upward and keep it dispersed. The apparatus, the method and the system for preparing spherical composite powder provided by the embodiments of the present invention can prepare spherical composite powder at low cost, simply and efficiently.

Description

Technical Field

[0001] The present invention belongs to the technical field of powder preparation, and particularly relates to an apparatus, a method and a system for preparing spherical composite powder. Background Art

[0002] With the development of rail transit, 5G communication technology and the continuous emergence of new materials, the requirements for the performance of workpiece materials in various fields are getting higher and higher. Composite materials are composed of two or more materials with different chemical and physical properties, and maintain the advantages of each component material. Due to the complementarity and correlation of the component properties, composite materials can obtain comprehensive properties that cannot be achieved by single materials. At present, metal matrix and ceramic matrix composite materials have gradually attracted people's attention due to their excellent properties. Sub-micron powders are agglomerated due to the intermolecular attraction and the interaction between particles, which greatly limits their application fields. Spherical powders have been increasingly widely used in many fields due to their excellent fluidity and high tapped density. For example, in the field of thermal spraying, due to their good fluidity, the coatings have better wear resistance; in the field of powder metallurgy, the formed parts prepared from spherical powders have high density and uniform shrinkage, so the obtained products have high precision and are of great value in the fields of injection molding and additive manufacturing. At present, the methods for preparing spherical powders include gas atomization method, plasma torch method and rotating electrode atomization method. However, the plasma torch method and the rotating electrode atomization method have not been used due to high costs and the fact that the gas atomization method is not suitable for preparing composite powders.

[0003] Therefore, there is an urgent need in the industry for a technical solution for spherical composite powders that is low-cost, simple and efficient to prepare. Summary of the Invention

[0004] The purpose of the present invention is to provide an apparatus, a method and a system for preparing spherical composite powders, which can prepare spherical composite powders at low cost, simply and efficiently.

[0005] To achieve the above purpose, the present invention provides the following technical solutions:

[0006] In a first aspect of the present invention, an apparatus for preparing spherical composite powder is provided, including a spheroidizing generator and a blowing device;

[0007] The spheroidizing generator includes a housing, and a cavity is provided inside the housing; a spray gun is provided at the top of the housing; the outlet of the spray gun is located inside the cavity, and the inlet of the spray gun is connected to a slurry preparation container through a slurry pipe;

[0008] The air outlet of the blowing device is communicated with the bottom opening of the housing, so that the gas sent by the blowing device into the cavity can blow the raw material powder in the cavity upward and keep it dispersed.

[0009] In one embodiment of the present invention, the housing includes an inner housing and an outer housing, and an ultrasonic medium is provided in the gap formed between the two; a plurality of ultrasonic generators are provided outside the outer housing.

[0010] In one embodiment of the present invention, an exhaust valve is provided at the top of the housing.

[0011] Preferably, a peristaltic pump is provided on the slurry pipe.

[0012] In one embodiment of the present invention, a cylindrical connecting portion extends downward from the bottom of the housing, and an annular clamping protrusion is provided at the bottom end of the connecting portion;

[0013] The air supply device is a cyclone generator, which includes an upper housing and a lower housing. The upper housing is sleeved on the bottom end of the connecting portion and is supported by the clamping protrusion. The lower housing is detachably connected to the upper housing; the top of the lower housing abuts against the bottom surface of the clamping protrusion; a plurality of air inlet pipes are provided on the side wall of the lower housing, and each air inlet pipe is connected to a gas source.

[0014] In one embodiment of the present invention, there is an air inlet gap between the lower housing and the bottom end of the connecting portion; or

[0015] Air inlet holes are provided on the side wall of the bottom end of the connecting portion;

[0016] Preferably, a screen is provided at the top end of the connecting portion.

[0017] The second aspect of the present invention also provides a method for preparing spherical composite powder, using the above-mentioned equipment for preparing spherical composite powder. The method includes the following steps:

[0018] A. In the slurry preparation container, a binder, a dispersant, a wetting agent, and a solvent are mixed evenly, and 0 or at least 1 kind of the first raw material powder is added and mixed evenly to obtain a slurry; the first raw material powder includes metal powder and ceramic powder;

[0019] B. At least 1 kind of the second raw material powder is added into the cavity of the spheroidizing generator; the second raw material powder includes metal powder and ceramic powder;

[0020] C. The slurry is transported into the spray gun by a peristaltic pump, and the slurry is sprayed out of the spray gun into the cavity of the spheroidizing generator by using compressed air as the power;

[0021] D. The air supply device is turned on, and compressed air is input into the cavity of the spheroidizing generator for spheroidizing treatment to obtain spherical composite powder.

[0022] In one embodiment of the present invention, in the step D, an ultrasonic generator provided on the housing is turned on to shake off the spherical composite powder adhered to the inner wall of the housing.

[0023] Preferably, the power of the ultrasonic generator is 25 - 40 KW.

[0024] More preferably, in the step A, a pore-forming agent is further added to the slurry preparation container to form a porous spherical composite powder.

[0025] In one embodiment of the present invention, the method for preparing the spherical composite powder further includes the steps:

[0026] E. Place the prepared spherical composite powder in a drying oven for drying, and then put it into a sintering furnace for sintering treatment.

[0027] F. After sintering, perform sieving and grading for standby.

[0028] Preferably, in the step E, the sintering furnace includes a sintering chamber and a sintering air supply device; there is a sintering cavity in the sintering chamber, and a container for placing the spherical composite powder is provided in the sintering cavity, and the container can release the spherical composite powder inside; a heating device is also provided in the sintering cavity; the air outlet of the sintering air supply device is communicated with the bottom of the sintering chamber, so that the gas sent by the sintering air supply device can blow the released spherical composite powder upward and keep it dispersed; the sintering treatment in the step E includes:

[0029] E1. Place the spherical composite powder in the container, and heat it up through the heating device to perform pre-sintering and degumming treatment on the spherical composite powder in the container.

[0030] E2. Pass an upward-flowing gas into the sintering cavity of the sintering chamber through the sintering air supply device, and then release the spherical composite powder in the container, so that the spherical composite powder is blown up by the upward-flowing gas and kept dispersed.

[0031] E3. Continue to raise the temperature and keep it warm for a predetermined time.

[0032] E4. Stop heating, and the sintering air supply device stops supplying air. After cooling to room temperature, collect the powder product.

[0033] In one embodiment of the present invention, the binder is BR73, BR113, BR115 or BR106, the dispersant is triethylhexyl phosphate, sodium dodecyl sulfate or a mixed solution of sodium dodecylbenzenesulfonate and a 30% toluene solution; the wetting agent is PEG1000, PEG1500 or PEG2000; the solvent is isopropyl alcohol, ethyl acetate or n-butyl acetate;

[0034] Preferably, in the slurry, by weight ratio, the binder is 5-10%, the dispersant is 0-2%, the wetting agent is 3-5%, the solvent is 50-60%, and the first raw material powder is 0-40%;

[0035] More preferably, in step C, the rate of the peristaltic pump is 3-15 mL / min, and the air pressure of the compressed air is 0.3-2 MPa; in step D, the flow rate of the compressed air is 30-50 sccm.

[0036] The third aspect of the present invention further provides a system for preparing spherical composite powder, including the described equipment and a sintering furnace;

[0037] The sintering furnace includes a sintering chamber and a sintering air supply device; there is a sintering cavity in the sintering chamber, and a container for placing the spherical composite powder is provided in the sintering cavity, and the container can release the internal spherical composite powder; a heating device is also provided in the sintering cavity; the air outlet of the sintering air supply device is communicated with the bottom of the sintering chamber, so that the gas sent by the sintering air supply device can blow up the released spherical composite powder upward and keep it dispersed.

[0038] Compared with the prior art, the advantages and beneficial effects of the embodiments of the present invention are as follows:

[0039] The current spheroidizing equipment is mainly used for the preparation of metal or alloy powders. However, the equipment, method and system for preparing spherical composite powders provided by the embodiments of the present invention have simple equipment and can be used for the spheroidizing treatment of heterogeneous mixed powders. Compared with the traditional spherical powder preparation method, the method provided by the embodiments of the present invention can not only prepare metal and alloy powders into spherical powders, but also prepare heterogeneous powders. In the embodiments of the present invention, the airflow generated by the cyclone generator suspends the powder, and then the colloid sprayed by the high-pressure spray gun adheres the suspended powder into a sphere, and the sphericity of the prepared spherical composite powder is high. The ultrasonic generator in the embodiments of the present invention can prevent the powder from adhering to the side wall and the bottom and affecting the spheroidizing process. Description of the Drawings

[0040] The accompanying drawings forming a part of the present invention are used to provide a further understanding of the present invention. The schematic embodiments of the present invention and their descriptions are used to explain the present invention and do not unduly limit the present invention. Among them:

[0041] Figure 1 It is a schematic three-dimensional structure diagram of the equipment for preparing spherical composite powder provided by an embodiment of the present invention;

[0042] Figure 2 It is a top view of the equipment for preparing spherical composite powder provided by an embodiment of the present invention;

[0043] Figure 3 It is a longitudinal sectional view of the equipment for preparing spherical composite powder provided by an embodiment of the present invention;

[0044] Figure 4 It is a schematic three-dimensional structure diagram of the sintering furnace in the system for preparing spherical composite powder provided by an embodiment of the present invention;

[0045] Figure 5 It is a longitudinal sectional view of the sintering furnace in the system for preparing spherical composite powder provided by an embodiment of the present invention;

[0046] Figure 6 It is a photograph of the spherical composite powder provided by Embodiment 1 of the present invention.

[0047] Explanation of reference numerals:

[0048] 1 - Spheroidizing generator, 11 - Housing, 111 - Inner housing, 112 - Outer housing, 113 - Gap, 12 - Cavity, 13 - Spray gun, 14 - Exhaust valve, 15 - Ultrasonic generator, 16 - Connecting part, 161 - Clamping projection, 2 - Air supply device, 21 - Upper housing, 22 - Lower housing, 23 - Air inlet pipe, 3 - Sintering furnace, 31 - Sintering chamber, 311 - Sintering cavity, 312 - Leg, 313 - Exhaust valve, 314 - Temperature measuring device installation part, 32 - Sintering air supply device, 321 - Upper shell, 322 - Lower shell, 323 - Pipeline, 4 - Container, 41 - Rotating shaft, 5 - Heating device, 6 - Collection part. Detailed description of the specific implementation

[0049] The present invention will be described in detail below with reference to the accompanying drawings and in conjunction with embodiments. Each example is provided by way of explanation of the present invention rather than limitation of the present invention. In fact, those skilled in the art will clearly understand that modifications and variations can be made to the present invention without departing from the scope or spirit of the present invention. For example, features shown or described as part of one embodiment can be used in another embodiment to produce yet another embodiment. Therefore, it is desirable that the present invention includes such modifications and variations that fall within the scope of the appended claims and their equivalents.

[0050] In the description of the present invention, terms such as "first", "second" and the like do not denote any order, quantity or importance, but are only used to distinguish different components. Terms such as "comprising" or "including" mean that the elements or objects appearing before this word cover the elements or objects listed after this word and their equivalents, without excluding other elements or objects. The orientation or positional relationships indicated by terms such as "longitudinal", "transverse", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", etc. are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention rather than requiring the present invention to be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation to the present invention. The terms "connected", "joined" and "arranged" used in the present invention should be understood in a broad sense. For example, they can be fixedly connected or detachably connected; they can be directly connected or indirectly connected through intermediate components; they can be wired connections, radio connections, or wireless communication signal connections. For those of ordinary skill in the art, the specific meanings of the above terms can be understood according to specific circumstances.

[0051] As Figure 1 、 Figure 2 shown, an embodiment of the present invention provides a device for preparing spherical composite powder, including a spheroidizing generator 1 and a blowing device 2.

[0052] As Figure 3 shown, the spheroidizing generator 1 includes a housing 11, which has a cavity 12 therein for containing raw material powder, such as one or more raw material powders that make up the spherical composite powder to be prepared. The top of the housing 11 is provided with a spray gun 13, the outlet of the spray gun 13 is located in the cavity 12, and the inlet of the spray gun 13 is connected to a slurry preparation container (not shown in the figure) through a slurry pipe. The spray gun 13 is used to spray slurry into the cavity 12 of the spheroidizing generator 1 to prepare spherical powder, and the slurry preparation container is used to prepare slurry (containing a binder, a dispersant, a wetting agent, a solvent, and 0 or at least 1 kind of raw material powder). Preferably, a peristaltic pump (not shown in the figure) is provided on the slurry pipe to pump the slurry into the spray gun 13. The inlet of the spray gun 13 is also connected to a compressed air pipeline (not shown in the figure) to provide power for spraying the slurry by the spray gun 13. In order to facilitate the addition of solid raw material powder into the cavity 12 of the spheroidizing generator 1, the top of the housing has an openable upper cover.

[0053] The air outlet of the air supply device 2 is communicated with the bottom opening of the housing 11, so that the gas sent into the cavity 12 by the air supply device 2 can blow up the raw material powder in the cavity 12 upward and keep it dispersed. The communication between the air outlet of the air supply device 2 and the bottom opening of the housing 11 can be a direct connection or a connection through a pipeline, without limitation. Further, an exhaust valve 14 is provided on the housing 11 to discharge the gas in the cavity 12 of the spheroidization generator 1.

[0054] When the device for preparing spherical composite powder provided by the embodiment of the present invention is in use, the slurry (containing a binder, a dispersant, a wetting agent, a solvent, and 0 or at least 1 kind of raw material powder) is sprayed into the cavity 12 of the spheroidization generator 1 through the spray gun 13. At the same time, the gas input into the cavity 12 by the air supply device 2 blows up the raw material powder in the cavity 12 and keeps it dispersed. The slurry aerosol and the raw material powder are evenly contacted and spheroidized to obtain spherical composite powder. Compared with the existing devices for preparing spherical powder, the device of the embodiment of the present invention has a low manufacturing cost, the slurry aerosol and the raw material powder are evenly contacted, the spherical composite powder prepared has a high sphericity, and the surface coating of large particle powder can be realized.

[0055] Since the raw material powder in the cavity 12 of the spheroidization generator 1 is blown up by the air flow input by the air supply device 2 and mixed with the slurry aerosol sprayed by the spray gun 13, the prepared spherical composite powder will slowly adhere to the inner wall of the cavity 12 of the spheroidization generator 1. To solve the above problems, as Figure 3 shown, in the embodiment of the present invention, the housing 11 includes an inner housing 111 and an outer housing 112. An ultrasonic medium, such as water, is provided in the gap 113 formed therebetween. The top of the gap 113 can be open and communicated with the outside. A plurality of ultrasonic generators 15 are provided outside the outer housing 112 for vibrating down the spherical composite powder adhering to the inner wall of the cavity 12 of the spheroidization generator 1 to prevent it from accumulating thicker and thicker.

[0056] In the embodiment of the present invention, in order to realize the connection between the air supply device 2 and the spheroidization generator 1, a cylindrical connecting portion 16, such as a cylindrical shape, extends downward from the bottom of the housing 11 of the spheroidization generator 1. An annular clamping convex 161 is provided at the bottom end of the connecting portion 16. The air supply device 2 is a cyclone generator, including an upper housing 21 and a lower housing 22. The upper housing 21 is sleeved on the bottom end of the connecting portion 16 and supported by the clamping convex 161 to limit the downward movement of the upper housing 21. The lower housing 22 is detachably connected to the upper housing 21, for example, by bolt connection. The top of the lower housing 22 abuts against the bottom surface of the clamping convex 161 to limit the upward movement of the lower housing 22. A plurality of air inlet pipes 23 are provided on the side wall of the lower housing 22, and each air inlet pipe 23 is connected to a gas source (not shown in the figure), such as compressed air.

[0057] The gas passage between the air supply device 2 and the connecting portion 16 may be as follows: there is an intake gap between the lower housing 22 and the bottom end of the connecting portion 16; or intake holes are provided on the side wall of the bottom end of the connecting portion 16 to send gas into the connecting portion 16. At this time, the gap corresponding to the connecting portion 16 between the upper housing 21 and the lower housing 22 is equivalent to the air outlet of the air supply device 2.

[0058] In order to collect the prepared spherical composite powder product and prevent it from falling into the air supply device, a screen is provided at the top end of the connecting portion 16.

[0059] An embodiment of the present invention further provides a system for preparing spherical composite powder, including the above-mentioned equipment and a sintering furnace 3.

[0060] As Figure 4 、 Figure 5 shown, the sintering furnace 3 includes a sintering chamber 31 and a sintering air supply device 32. The sintering chamber 31 has a sintering cavity 311. A container 4 for placing the spherical composite powder is provided in the sintering cavity 311. The container 4 can release the internal spherical composite powder. For example, by rotating the rotating shaft 41 connected to the container 4, its opening can be rotated downward. A heating device 5, such as a resistance wire, is also provided in the sintering cavity 311 to heat the sintering cavity 311. Legs 312 extend downward from the bottom edge of the sintering chamber 31 to support the sintering chamber 31. The sintering air supply device 32 can be a cyclone generator, including an upper shell 321 and a lower shell 322, which are connected to a gas source through a pipeline 323, such as a mixed gas of one or more of compressed air, nitrogen, argon, hydrogen, methane, and ammonia. The air outlet of the sintering air supply device 32 is communicated with the bottom of the sintering chamber 31, so that the gas sent by the sintering air supply device 32 can blow the released spherical composite powder upward and keep it dispersed for dynamic sintering of the spherical composite powder. An exhaust valve 313 for exhausting gas and a temperature measuring device installation portion 314 for installing a temperature measuring device (such as a thermometer, thermocouple) are also provided on the side wall of the sintering chamber 31. In order to facilitate the collection of product powder, a collection portion 6 with a gradually decreasing inner diameter is provided at the bottom of the sintering chamber 31.

[0061] The sintering furnace 3 provided by the embodiments of the present invention can release the spherical composite powder from the container 4 during sintering and blow it up by the upward air flow, so that the spherical composite powder has a high dispersion degree during sintering, rapid and uniform heat transfer, and can avoid the spherical composite powder from being sintered together. After sintering, the original shape (such as spherical multi-edge angle) and size (such as particle size) of the spherical composite powder can be maintained. In addition, since there is no need to reduce the sintering temperature as in the prior art (to avoid the spherical composite powder from being sintered together), the spherical composite powder in the embodiments of the present invention can be sintered at a high temperature. The higher the temperature, the greater the strength of the sintered powder. Therefore, the maximum strength sintering of the spherical composite powder can be achieved.

[0062] The embodiments of the present invention further provide a method for preparing spherical composite powder. Using the above-mentioned equipment for preparing spherical composite powder, the method includes the following steps:

[0063] A. In the slurry preparation container, mix the binder, dispersant, wetting agent and solvent evenly, and add 0 or at least 1 kind of the first raw material powder (that is, the raw material powder can be not added to the slurry, or 1 or more kinds of raw material powder can be added), and mix evenly to obtain the slurry; the first raw material powder includes metal powder and ceramic powder; specifically, the binder can be an acrylic resin, such as a mixed solution of BR73, BR113, BR115 or BR106 and 30% toluene solution (BR73 and similar numbers are the grades of thermoplastic acrylic resins of Mitsubishi in Japan), the dispersant can be a mixed solution of triethylhexyl phosphate, sodium dodecyl sulfate or sodium dodecylbenzenesulfonate and 30% toluene solution; the wetting agent can be PEG1000 (polyethylene glycol 1000), PEG1500 (polyethylene glycol 1500) or PEG2000 (polyethylene glycol 2000); the solvent can be isopropyl alcohol, ethyl acetate or n-butyl acetate; further, in the slurry, by weight ratio, the binder is 5-10%, the dispersant is 0-2%, the wetting agent is 3-5%, the solvent is 50-60%, and the first raw material powder is 0-40%;

[0064] B. Add at least 1 kind of the second raw material powder into the cavity 12 of the spheroidizer 1; the second raw material powder includes metal powder and ceramic powder; as an optional embodiment, the components of the first raw material powder include one or more of silicon carbide, tungsten carbide, cobalt, W5 diamond, and ceramic binder, and the second raw material powder includes one or more of silicon carbide, tungsten carbide, cobalt, W5 diamond, and ceramic binder.

[0065] C. Use a peristaltic pump to transport the slurry into the interior of the spray gun 13, and use compressed air as the power to spray the slurry from the spray gun 13 into the cavity 12 of the spheroidization generator 1; preferably, in step C, the rate of the peristaltic pump is 3 - 15 mL / min (such as 3 mL / min, 5 mL / min, 7 mL / min, 9 mL / min, 11 mL / min, 13 mL / min, 15 mL / min), and the air pressure of the compressed air is 0.3 - 2 MPa (such as 0.3 MPa, 0.5 MPa, 0.7 MPa, 0.9 MPa, 1.3 MPa, 1.5 MPa, 1.7 MPa, 1.9 MPa, 2 MPa);

[0066] D. Turn on the air supply device 2, input compressed air into the cavity 12 of the spheroidization generator 1, with a flow rate of 30 - 50 sccm (such as 30 sccm, 35 sccm, 40 sccm, 45 sccm, 50 sccm), perform spheroidization treatment to obtain spherical composite powder. In step D, turn on the ultrasonic generator 15 provided on the housing 11 to shake off the spherical composite powder adhering to the inner wall of the housing 11 to prevent it from accumulating thicker and thicker. Preferably, the power of the ultrasonic generator 15 is 25 - 40 KW (such as 25 KW, 30 KW, 35 KW, 40 KW).

[0067] In the method for preparing spherical composite powder provided by the embodiment of the present invention, when preparing the slurry in step A, any one of the raw material powders to be prepared into the composite powder may not be put in. At this time, all the raw material powders of the composite powder to be prepared are mixed evenly and then put into the cavity 12 of the spheroidization generator 1, and the slurry sprayed by the spray gun 13 only contains additives (binder, dispersant, wetting agent, solvent); it is also possible to put one or more raw material powders of the composite powder to be prepared when preparing the slurry, and put the remaining raw material powders of the composite powder to be prepared into the cavity 12 of the spheroidization generator 1.

[0068] Compared with the existing method for preparing spherical powder, the slurry aerosol in the embodiment of the present invention contacts the raw material powder more evenly, the prepared spherical composite powder has a high sphericity, can control the particle size by adjusting the time, and realizes the surface coating treatment of larger particles.

[0069] As an alternative embodiment, in order to obtain porous spherical composite powder, in step B, 0 - 5% of a pore-forming agent is further added to the spheroidization generator to finally form porous spherical composite powder, and the pore-forming agent can be one of PS (polystyrene), PMMA (polymethyl methacrylate), carbon black, PVA (polyvinyl alcohol), and PVB (polyvinyl butyral).

[0070] Furthermore, the method for preparing spherical composite powder further includes the steps:

[0071] E. Place the prepared spherical composite powder in a drying oven for drying, and then put it into a sintering furnace for sintering treatment;

[0072] F. After sintering, perform sieving and grading for later use.

[0073] Preferably, as Figure 4 、 Figure 5 shown, the sintering furnace 3 includes a sintering chamber 31 and a sintering air supply device 32. The sintering chamber 31 has a sintering cavity 311. A container 4 for placing the spherical composite powder is provided in the sintering cavity 311. The container 4 can release the internal spherical composite powder. For example, by rotating the rotating shaft 41 connected to the container 4, its opening can be rotated downward. A heating device 5, such as a resistance wire, is also provided in the sintering cavity 311 to heat the sintering cavity 311. The bottom edge of the sintering chamber 31 extends downward to form legs 312 for supporting the sintering chamber 31. The sintering air supply device 32 can be a cyclone generator, including an upper shell 321 and a lower shell 322, which is connected to a gas source, such as a mixed gas of one or several of compressed air, nitrogen, argon, hydrogen, methane, and ammonia, through a pipeline 323. The air outlet of the sintering air supply device 32 is communicated with the bottom of the sintering chamber 31, so that the gas sent by the sintering air supply device 32 can blow the released spherical composite powder upward and keep it dispersed for dynamic sintering of the spherical composite powder. An exhaust valve 313 for exhausting gas and a temperature measuring device installation part 314 for installing a temperature measuring device (such as a thermometer, thermocouple) are also provided on the side wall of the sintering chamber 31. In order to facilitate the collection of product powder, a collection part 6 with a gradually decreasing inner diameter is provided at the bottom of the sintering chamber 31. The sintering treatment in step E includes:

[0074] E1. Place the spherical composite powder in the container 4, heat it up through the heating device 5, and perform pre-sintering and degumming treatment on the spherical composite powder in the container 4; preferably, the heating rate during pre-sintering is 4 - 8 °C / min, and it is kept warm for 60 - 180 min respectively when the temperature rises to 100 - 120 °C, 300 - 330 °C, and 500 - 700 °C;

[0075] E2. Pass an upward-flowing gas into the sintering cavity 311 of the sintering chamber 31 through the sintering air supply device 32, and then release the spherical composite powder in the container 4, so that the spherical composite powder is blown up by the upward-flowing gas and kept dispersed; the gas sent by the sintering air supply device 32 can be one or several of compressed air, nitrogen, argon, hydrogen, methane, and ammonia; preferably, the flow rate of the gas sent by the sintering air supply device 32 is 40 - 100 sccm;

[0076] E3. Continuously raise the temperature (650 - 920 °C) and hold for a predetermined time (180 - 400 min);

[0077] E4. Stop heating, stop the air supply of the sintering air supply device 32, and collect the powder product after cooling to room temperature.

[0078] The following are several examples of the method for preparing spherical composite powder provided by the present invention.

[0079] Example 1

[0080] A. In the slurry preparation container, mix 10% binder (select BR73), 2% dispersant, 3% wetting agent (select PEG1000), and 50% solvent (select isopropyl alcohol) evenly to obtain a slurry;

[0081] B. Add 30% of W5 diamond and 12% of ceramic binder powder into the cavity 12 of the spheroidizer 1;

[0082] C. Use a peristaltic pump to transport the slurry into the spray gun 13 at a rate of 15 mL / min, and spray the above slurry from the spray gun 13 with clean compressed air as the power, where the gas pressure is 2 MPa;

[0083] D. Turn on the switch of the air supply device 2 to input clean compressed air into the cavity 12 of the spheroidizer 1, blow up the raw material powder in the cavity 12 of the spheroidizer 1 and keep it dispersed for spheroidization treatment. The gas flow rate of the compressed air is 50 sccm to obtain spherical composite powder, as Figure 6 shown.

[0084] Example 2

[0085] A. In the slurry preparation container, mix 10% binder (select BR113), 2% dispersant, 5% wetting agent (select PEG1500), and 50% solvent (select ethyl acetate) evenly to obtain a slurry;

[0086] B. Add 30% of W5 diamond and 10% of ceramic binder mixed powder (the powder has been mixed evenly and has been cured) into the cavity 12 of the spheroidizer 1;

[0087] C. Use a peristaltic pump to transport the slurry into the spray gun 13 at a rate of 15 mL / min, and spray the above slurry from the spray gun 13 with clean compressed air as the power, where the gas pressure is 0.3 MPa;

[0088] D. Turn on the switch of the air supply device 2 to input clean compressed air into the cavity 12 of the spheroidizer 1, blow up the raw material powder in the cavity 12 of the spheroidizer 1 and keep it dispersed, and carry out spheroidization treatment. The gas flow rate of the compressed air is 50 sccm, and a quasi-spherical composite powder is obtained. During the spheroidization process, turn on the ultrasonic generator 15 outside the housing and set the power of the ultrasonic generator 15 to 40 KW;

[0089] E. Place the prepared quasi-spherical composite powder in a drying oven for drying, and then put it into a sintering furnace for sintering treatment; The sintering preferably uses Figure 4 、 Figure 5 The sintering furnace 3 shown in the figure is used for dynamic sintering; When pre-sintering, the heating rate is 4 °C / min, and it is kept warm for 120 min at 120 °C, 330 °C, and 550 °C respectively; When sintering, the temperature is 650 °C and it is kept warm for 200 min; The gas flow rate of the compressed air transported by the sintering air supply device 32 is 30 sccm;

[0090] F. After sintering, carry out sieving and grading for later use.

[0091] Example 3

[0092] A. In this slurry preparation container, mix 10% binder (select BR115), 2% dispersant, 5% wetting agent (select PEG2000), silicon carbide with a mass fraction of 5% of the diamond mass, and 60% solvent (select n-butyl acetate) evenly to obtain a slurry;

[0093] B. Add 30% of the W5 diamond and 10% of the ceramic binder mixed powder into the cavity 12 of the spheroidizer 1;

[0094] C. Use a peristaltic pump to transport the slurry into the spray gun 13 at a rate of 15 mL / min, and spray the above slurry from the spray gun 13 with clean compressed air as the power, where the gas pressure is 2 MPa;

[0095] D. Turn on the switch of the air supply device 2 to input clean compressed air into the cavity 12 of the spheroidizer 1, blow up the raw material powder in the cavity 12 of the spheroidizer 1 and keep it dispersed, and carry out spheroidization treatment. The gas flow rate of the compressed air is 50 sccm, and a quasi-spherical composite powder is obtained. During the spheroidization process, turn on the ultrasonic generator 15 outside the housing and set the power of the ultrasonic generator 15 to 40 KW;

[0096] E. Place the prepared quasi-spherical composite powder in a drying oven for drying, and then put it into a sintering furnace for sintering treatment; The sintering preferably uses Figure 4 、 Figure 5The sintering furnace 3 shown is used for dynamic sintering; during pre-sintering, the heating rate is 4 °C / min, and it is kept warm for 120 min at 120 °C, 330 °C, and 550 °C respectively; during sintering, the temperature is 650 °C and it is kept warm for 200 min; the flow rate of the compressed air conveyed by the sintering air supply device 32 is 30 sccm;

[0097] F. After sintering is completed, screening and classification are carried out for standby.

[0098] Example 4

[0099] A. In the slurry preparation container, 10% binder (select BR106), 2% dispersant, 5% wetting agent (select PEG2000), silicon carbide with a mass fraction of 5% of the diamond mass, and 60% solvent (select ethyl acetate) are mixed evenly to obtain a slurry;

[0100] B. 25% of W5 diamond, 5% pore-forming agent (select carbon black), and 10% ceramic binder mixed powder are added into the cavity 12 of the spheroidizer 1;

[0101] C. A peristaltic pump is used to convey the slurry into the spray gun 13 at a rate of 15 mL / min, and the above slurry is sprayed out from the spray gun 13 driven by clean compressed air, where the gas pressure is 2 MPa;

[0102] D. The switch of the air supply device 2 is turned on to input clean compressed air into the cavity 12 of the spheroidizer 1, and the raw material powder in the cavity 12 of the spheroidizer 1 is blown up and kept dispersed for spheroidization treatment. The gas flow rate of the compressed air is 50 sccm to obtain a spherical composite powder. During the spheroidization process, the ultrasonic generator 15 outside the housing is turned on, and the power of the ultrasonic generator 15 is set to 40 KW;

[0103] E. The prepared spherical composite powder is placed in a drying oven for drying, and then put into a sintering furnace for sintering treatment; sintering is preferably carried out using Figure 4 、 Figure 5 the sintering furnace 3 shown, for dynamic sintering; during pre-sintering, the heating rate is 4 °C / min, and it is kept warm for 120 min at 120 °C, 330 °C, and 550 °C respectively; during sintering, the temperature is 650 °C and it is kept warm for 200 min; the flow rate of the compressed air conveyed by the sintering air supply device 32 is 30 sccm;

[0104] F. After sintering is completed, screening and classification are carried out for standby to obtain a porous spherical composite powder product.

[0105] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A method for preparing spherical composite powder, characterized in that, Using a device for preparing spherical composite powder, the device including a spheroidizing generator and an air supply device; The spheroidizing generator includes a housing with a cavity inside; a spray gun is provided at the top of the housing; the outlet of the spray gun is located inside the cavity, and the inlet of the spray gun is connected to a slurry preparation container through a slurry pipe; The air outlet of the air supply device is communicated with the bottom opening of the housing, so that the gas sent into the cavity by the air supply device can blow up the raw material powder in the cavity upward and keep it dispersed, The housing includes an inner housing and an outer housing, and an ultrasonic medium is provided in the gap formed between the two; several ultrasonic generators are provided outside the outer housing, The air supply device is a cyclone generator, The method includes the following steps: A. In the slurry preparation container, mix a binder, a dispersant, a wetting agent and a solvent evenly, and add 0 or at least 1 of the first raw material powders; the first raw material powders include metal powders and ceramic powders; mix evenly to obtain a slurry; B. Add at least 1 of the second raw material powders into the cavity of the spheroidizing generator; the second raw material powders include metal powders and ceramic powders; C. Use a peristaltic pump to transport the slurry into the spray gun, and use compressed air as the power to spray the slurry from the spray gun into the cavity of the spheroidizing generator; D. Open the air supply device, input compressed air into the cavity of the spheroidizing generator, and perform spheroidizing treatment to obtain spherical composite powder; E. Place the prepared spherical composite powder in a drying oven for drying, and then put it into a sintering furnace for sintering treatment; F. After sintering, perform sieving and grading for later use; In step E, the sintering furnace includes a sintering chamber and a sintering air supply device; There is a sintering cavity in the sintering chamber, and a container for placing the spherical composite powder is provided in the sintering cavity, and the container can release the spherical composite powder inside; a heating device is also provided in the sintering cavity; the air supply port of the sintering air supply device is communicated with the bottom of the sintering chamber, so that the gas sent by the sintering air supply device can blow up the released spherical composite powder upward and keep it dispersed; The sintering treatment in step E includes: E1. Place the spherical composite powder in the container, heat and raise the temperature through the heating device, and perform pre-sintering and debinding treatment on the spherical composite powder in the container; E2. Pass an upward flowing gas into the sintering cavity of the sintering chamber through the sintering air supply device, and then release the spherical composite powder in the container, so that the spherical composite powder is blown up by the upward flowing gas and kept dispersed; E3. Continue to raise the temperature and keep it warm for a predetermined time; E4. Stop heating, the sintering air supply device stops supplying air, and collect the powder product after cooling to room temperature, The sintering furnace also includes a rotating shaft, a collection part, a temperature measuring device and a temperature measuring device installation part, The rotating shaft is connected to the container and is used to release the spherical composite powder inside the container by rotation, The collection part is arranged at the bottom of the sintering chamber, The temperature measuring device installation part is used to install the temperature measuring device.

2. The method for preparing the spherical composite powder according to claim 1, characterized in that, An exhaust valve is provided at the top of the housing; A peristaltic pump is provided on the slurry pipe.

3. The method for preparing spherical composite powder according to claim 1, characterized in that A cylindrical connecting portion extends downward from the bottom of the housing, and an annular clamping convex is provided at the bottom end of the connecting portion; It includes an upper housing and a lower housing. The upper housing is sleeved on the bottom end of the connecting portion and is supported by the clamping convex. The lower housing is detachably connected to the upper housing; the top of the lower housing abuts against the bottom surface of the clamping convex; a plurality of air inlet pipes are provided on the side wall of the lower housing, and each air inlet pipe is connected to a gas source.

4. The method for preparing spherical composite powder according to claim 3, characterized in that There is an air inlet gap between the bottom end of the lower housing and the connecting portion; A screen is provided at the top end of the connecting portion.

5. The method for preparing spherical composite powder according to claim 3, characterized in that Air inlet holes are provided on the side wall of the bottom end of the connecting portion; A screen is provided at the top end of the connecting portion.

6. The method for preparing spherical composite powder according to any one of claims 4 or 5, characterized in that In step D, turn on the ultrasonic generator provided on the housing to shake off the spherical composite powder adhered to the inner wall of the housing; The power of the ultrasonic generator is 25 - 40 KW; In step B, a pore-forming agent is also added to the spheroidizing generator.

7. The method for preparing spherical composite powder according to claim 6, characterized in that The binder is BR73, BR113, BR115 or BR106, the dispersant is triethylhexyl phosphate, sodium dodecyl sulfate or a mixed solution of sodium dodecylbenzenesulfonate and 30% toluene solution; the wetting agent is PEG1000, PEG1500 or PEG2000; the solvent is isopropyl alcohol, ethyl acetate or n-butyl acetate.

8. The method for preparing spherical composite powder according to claim 7, characterized in that In the slurry, by weight, the binder is 5 - 10%, the dispersant is 0 - 2%, the wetting agent is 3 - 5%, the solvent is 50 - 60%, and the first raw material powder is 0 - 40%.

9. The method for preparing spherical composite powder according to claim 7, characterized in that In step C, the rate of the peristaltic pump is 3 - 15 mL / min, and the air pressure of the compressed air is 0.3 - 2 MPa; in step D, the flow rate of the compressed air is 30 - 50 sccm.

10. A system for preparing spherical composite powder, characterized in that, It includes the method according to any one of claims 1 - 9 and a sintering furnace; The sintering furnace includes a sintering chamber and a sintering air supply device; there is a sintering cavity in the sintering chamber, and a container for placing the spherical composite powder is provided in the sintering cavity, and the container can release the spherical composite powder inside; a heating device is also provided in the sintering cavity; the air supply port of the sintering air supply device is communicated with the bottom of the sintering chamber, so that the gas sent by the sintering air supply device can blow the released spherical composite powder upward and keep it dispersed.

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