A nanoparticle composite metal powder atomization device and atomizer

Abstract

The present application belongs to the technical field of metal additive manufacturing, and discloses a nanoparticle composite metal powder atomization device and an atomizer. The atomizer includes a fixed crushing body and a centrifugal turntable. By arranging a crushing structure between the fixed crushing body and the centrifugal turntable, the mixed melt can be effectively blended and crushed, and the distribution uniformity of nanoparticles in the metal melt can be significantly improved, thereby solving the technical problems of nanoparticle agglomeration and uneven distribution in the traditional atomization process.

Description

Technical Field

[0001] The present application relates to the technical field of metal additive manufacturing, and in particular to a nano-particle composite metal powder atomization device and an atomizer. Background Art

[0002] Nanoparticle composite metal powder is a metal powder obtained by combining metal substrate and nanoparticles. Compared with pure metal substrate, nanoparticle composite metal materials usually have the advantages of higher strength, greater hardness and better wear resistance. This composite material has broad application prospects in aerospace, automobile manufacturing, electronics industry and other fields. At present, the application of laser selective melting technology (SLM) in composite material manufacturing has attracted more and more attention because it can produce metal-based composite materials with unique microstructure and mechanical properties at a lower cost. Nano-ceramic particle composite metal powder is a relatively commonly used nano-particle composite metal powder. The presence of nano-ceramic particles eliminates the preferential orientation of the metal substrate microstructure along a specific direction, accelerates heterogeneous nucleation, promotes the recrystallization process, hinders grain growth, and significantly refines the grains. The appropriate proportion of nanoparticle addition can effectively improve the performance of SLM printed parts.

[0003] However, there are some technical difficulties in the process of preparing nanoparticle composite metal powder. First, due to their special surface effects, nanoparticles are prone to serious agglomeration behavior. This agglomeration will lead to uneven distribution of nanoparticles in the metal matrix, thus affecting the performance of the composite material. Secondly, there is usually a significant density difference between the matrix metal and the nanoparticles. During centrifugal atomization, serious relative slip will occur between the nanoparticles and the melt of the matrix metal, which further aggravates the problem of uneven distribution.

[0004] The above problem is particularly prominent when using conventional atomization process to prepare nanoparticle composite metal powder in one go. The traditional atomization method is difficult to effectively disperse nanoparticles evenly in the metal melt, resulting in uneven distribution of nanoparticles in the final composite metal powder. This uneven distribution will seriously affect the performance of the composite material, making it unable to fully exert the reinforcing effect of nanoparticles.

[0005] In addition, existing atomization technologies often lack effective mixing and breaking mechanisms when processing nanoparticle composite metal melts. This causes the nanoparticles to easily form agglomerates during the atomization process and cannot be fully dispersed in the metal matrix. At the same time, due to the lack of an effective mixing process, the distribution of nanoparticles in the metal melt is also difficult to achieve an ideal uniform state.

[0006] How to achieve uniform distribution of nanoparticles in a one-time atomization preparation process has become a key technical problem in the preparation of high-performance nanoparticle composite metal powders. Solving this problem requires not only improving the structural design of the atomization equipment, but also optimizing the mixing, crushing and dispersion mechanisms during the atomization process.

[0007] In view of the above problems, the existing technology needs to be improved urgently. Summary of the invention

[0008] The purpose of the present application is to provide a nanoparticle composite metal powder atomization device and an atomizer, which can solve the problem of uneven distribution of nanoparticles in metal melt and improve the performance of composite metal powder.

[0009] In a first aspect, the present application provides an atomizer, comprising a coaxially arranged fixed crushing body, a centrifugal turntable and an atomizing spray disc; the centrifugal turntable is located below the fixed crushing body, a spacing space is provided between the lower surface of the fixed crushing body and the upper surface of the centrifugal turntable, the fixed crushing body is provided with a through hole that runs through the upper and lower parts and is connected to the spacing space, the through hole is used to inject a mixed melt formed by a mixture of nanoparticles and a metal melt into the spacing space; the centrifugal turntable is used to rotate to make the mixed melt perform centrifugal motion in the spacing space and finally fly out from the edge of the centrifugal turntable, and the atomizing spray disc is used to spray an airflow to atomize the mixed melt flying out of the centrifugal turntable;

[0010] The lower surface of the fixed crushing body is provided with a first characteristic structure, which includes a protruding structure and / or a concave structure. The upper surface of the centrifugal turntable is provided with a second characteristic structure, which includes a protruding structure and / or a concave structure. The first characteristic structure and the second characteristic structure are used to cooperate to form a crushing structure, and the crushing structure is used to mix and crush the mixed melt moving in the interval space.

[0011] By setting a crushing structure between the fixed crushing body and the centrifugal turntable, the mixed melt can be effectively blended and crushed, significantly improving the distribution uniformity of nanoparticles in the metal melt, and solving the technical problems of nanoparticle agglomeration and uneven distribution in the traditional atomization process.

[0012] Optionally, the crushing structure includes a plurality of first discrete protrusion bands, a plurality of first annular grooves, a plurality of second discrete protrusion bands and a plurality of second annular grooves, the first discrete protrusion band, the first annular groove, the second discrete protrusion band and the second annular groove are all coaxially arranged, the first discrete protrusion band includes a plurality of first protrusions evenly arranged in the circumferential direction, and the second discrete protrusion band includes a plurality of second protrusions evenly arranged in the circumferential direction; the first discrete protrusion band and the first annular groove are alternately arranged in the radial direction on the lower surface of the fixed crushing body to form the first characteristic structure, and the second discrete protrusion band and the second annular groove are alternately arranged in the radial direction on the upper surface of the centrifugal turntable to form the second characteristic structure; the first discrete protrusion band and the second annular groove are arranged one-to-one in a vertically opposite relationship, and the first annular groove and the second discrete protrusion band are arranged one-to-one in a vertically opposite relationship.

[0013] The crushing structure includes a plurality of first discrete raised bands, a plurality of first annular grooves, a plurality of second discrete raised bands and a plurality of second annular grooves. These structures are coaxially arranged and radially alternately spaced on the surfaces of the fixed crushing body and the centrifugal turntable. Through the interaction of these structures, when the mixed melt moves in the interval space, these concave-convex structures will produce collision and shearing effects on the mixed melt, which can effectively mix and crush it, thereby solving the mixing and crushing problems of the mixed melt during movement.

[0014] Optionally, the crushing structure includes a plurality of discrete groove bands and a plurality of third annular grooves, the discrete groove bands and the third annular grooves are coaxially arranged, and the discrete groove bands include a plurality of circular arc grooves evenly arranged along the circumferential direction; at least one of the discrete groove bands and / or at least one of the third annular grooves are arranged on the lower surface of the fixed crushing body to form the first characteristic structure, and at least one of the discrete groove bands and / or at least one of the third annular grooves are arranged on the upper surface of the centrifugal turntable to form the second characteristic structure; each of the discrete groove bands is arranged opposite to a third annular groove in the up and down directions, and at least one sphere is arranged between each of the circular arc grooves and the corresponding third annular groove, and the sphere is partially located in the corresponding circular arc groove and the corresponding third annular groove.

[0015] This design utilizes rolling spheres to fully mix and crush the mixed melt moving in the interval space, thereby solving the problem of uneven distribution of nanoparticles in the atomized powder.

[0016] Preferably, the upper surface of the centrifugal turntable is provided with a liquid falling zone, a second crushing zone and a second flying-off zone, the liquid falling zone is located at the center of the upper surface of the centrifugal turntable, the second flying-off zone is located at the edge of the upper surface of the centrifugal turntable, and the second crushing zone is located between the liquid falling zone and the second flying-off zone; the lower surface of the fixed crushing body is provided with a first crushing zone and a first flying-off zone, the first flying-off zone is located at the edge of the lower surface of the fixed crushing body, and the first crushing zone is located between the through hole and the first flying-off zone; the liquid falling zone is opposite to the through hole, the second crushing zone is opposite to the first crushing zone, and the second flying-off zone is opposite to the first flying-off zone;

[0017] The crushing structure is arranged between the first crushing zone and the second crushing zone, and the first fly-off zone and the second fly-off zone are both smooth surfaces.

[0018] Preferably, the first take-off area and the second take-off area are both horizontal planes;

[0019] Alternatively, both the first fly-off area and the second fly-off area are arc surfaces that gradually bend downward from the inside to the outside, and the normal distance between the first fly-off area and the second fly-off area is the same at any position.

[0020] Preferably, the liquid drop area is further provided with a plurality of third protrusions protruding upward.

[0021] Preferably, the fixed crushing body is capable of heating the mixed melt.

[0022] Preferably, an electric heating device is provided on the fixed crushing body;

[0023] Alternatively, the fixed crushing body is made of a conductive material, and the fixed crushing body is used to generate heat by being energized to heat the mixed melt.

[0024] In the second aspect, the present application provides a nanoparticle composite metal powder atomization equipment, comprising a smelting chamber and an atomization chamber arranged at the lower side of the smelting chamber, wherein a smelting tongs pot and a tundish are arranged in the smelting chamber, a guide nozzle is connected to the lower end of the tundish, and the guide nozzle extends into the atomization chamber, the smelting tongs pot is used to smelt the metal substrate to obtain a metal melt; the smelting tongs pot and / or the tundish are also used to mix the metal melt and nanoparticles to obtain a mixed melt; the atomizer and the drive motor mentioned above are arranged in the atomization chamber; the guide nozzle extends into the through hole of the atomizer or is arranged above the atomizer directly opposite the through hole, and the guide nozzle is used to output the mixed melt to the atomizer; the drive motor is used to drive the centrifugal turntable of the atomizer to rotate.

[0025] Preferably, a stirring device is provided in the smelting tongs and / or the tundish.

[0026] Beneficial effects: The nanoparticle composite metal powder atomization equipment and atomizer provided in the present application, the atomizer includes a fixed crushing body and a centrifugal turntable. By setting a crushing structure between the fixed crushing body and the centrifugal turntable, the mixed melt can be effectively blended and crushed, and the distribution uniformity of the nanoparticles in the metal melt can be significantly improved, which solves the technical problems of nanoparticle agglomeration and uneven distribution in the traditional atomization process. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 A schematic diagram of the structure of an atomizer provided in an embodiment of the present application.

[0028] Figure 2 for Figure 1 Bottom view of a fixed crushing body in an atomizer.

[0029] Figure 3 for Figure 1 Top view of the centrifugal turntable in the atomizer.

[0030] Figure 4 A schematic diagram of the structure of another atomizer provided in an embodiment of the present application.

[0031] Figure 5 for Figure 4 Bottom view of a fixed crushing body in an atomizer.

[0032] Figure 6 for Figure 4 Top view of the centrifugal turntable in the atomizer.

[0033] Figure 7 This is a schematic diagram of the structure of the nanoparticle composite metal powder atomization equipment provided in an embodiment of the present application.

[0034] Explanation of reference numerals: 1. fixed crushing body; 101. through hole; 102. first crushing zone; 103. first flying zone; 2. centrifugal turntable; 201. liquid falling zone; 202. second crushing zone; 203. second flying zone; 204. third protrusion; 3. atomizing spray disc; 301. flow channel; 4. crushing structure; 401. first discrete protrusion belt; 4011. first protrusion; 402. first annular groove; 403. second discrete protrusion belt; 4031. second protrusion; 404. second Annular groove; 405, discrete groove belt; 4051, arc groove; 406, third annular groove; 407, sphere; 100, atomizer; 200, smelting chamber; 300, atomization chamber; 400, smelting tongs pot; 500, tundish; 600, guide nozzle; 700, drive motor; 800, powder collecting device; 801, first powder collecting tank; 802, cyclone separator; 803, second powder collecting tank; 804, dust collector; 805, third powder collecting tank; 806, induced draft fan. DETAILED DESCRIPTION

[0035] The technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all of the embodiments. The components of the embodiments of the present application described and shown in the drawings here can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present application provided in the drawings is not intended to limit the scope of the application claimed for protection, but merely represents the selected embodiments of the present application. Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art without making creative work belong to the scope of protection of the present application.

[0036] It should be noted that similar reference numerals and letters represent similar items in the following drawings, so once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings. At the same time, in the description of this application, the terms "first", "second", etc. are only used to distinguish the description and cannot be understood as indicating or implying relative importance.

[0037] Nanoparticle composite metal powder is a metal powder obtained by combining metal substrate and nanoparticles. Compared with pure metal substrate, nanoparticle composite metal materials usually have the advantages of higher strength, greater hardness and better wear resistance. However, due to the serious agglomeration behavior of nanoparticles and the obvious difference in density between the base metal and the nanoparticles, when the nanoparticle composite metal powder is prepared in one time using the conventional atomization process, the nanoparticles are often unevenly distributed in the atomized powder. How to use a one-time atomization preparation process to prepare nanoparticle composite metal powder with uniform distribution of nanoparticles is an urgent problem to be solved.

[0038] To solve this problem, the present application proposes an innovative atomizer design.

[0039] Please refer to Figure 1-Figure 6 In some embodiments of the present application, an atomizer 100 comprises a coaxially arranged fixed crushing body 1, a centrifugal turntable 2 and an atomizing spray disc 3; the centrifugal turntable 2 is located below the fixed crushing body 1, and there is a spacing space between the lower surface of the fixed crushing body 1 and the upper surface of the centrifugal turntable 2, and the fixed crushing body 1 is provided with a through hole 101 that runs through the upper and lower parts and is connected to the spacing space, and the through hole 101 is used to inject a mixed melt formed by a mixture of nanoparticles and a metal melt into the spacing space; the centrifugal turntable 2 is used to rotate to make the mixed melt perform centrifugal motion in the spacing space and finally fly out from the edge of the centrifugal turntable 2, and the atomizing spray disc 3 is used to spray an airflow to atomize the mixed melt flying out of the centrifugal turntable 2;

[0040] The lower surface of the fixed crushing body 1 is provided with a first characteristic structure, which includes a convex structure and / or a concave structure. The upper surface of the centrifugal turntable 2 is provided with a second characteristic structure, which includes a convex structure and / or a concave structure. The first characteristic structure and the second characteristic structure are used to cooperate to form a crushing structure 4, and the crushing structure 4 is used to mix and crush the mixed melt moving in the interval space.

[0041] By arranging a crushing structure 4 between the fixed crushing body 1 and the centrifugal turntable 2, the mixed melt can be effectively blended and crushed, the distribution uniformity of the nanoparticles in the metal melt is significantly improved, and the technical problems of nanoparticle agglomeration and uneven distribution in the traditional atomization process are solved.

[0042] Specifically, through the above scheme, the combination of the fixed crushing body 1, the centrifugal turntable 2 and the atomizing spray disc 3 can effectively blend and crush the mixed melt, break the nanoparticle agglomerates in the mixed melt, so that the mixing between the nanoparticles and the metal melt is more uniform, and the relative slip caused by the density difference between the nanoparticles and the metal melt under the centrifugal action is eliminated, further improving the mixing uniformity between the nanoparticles and the metal melt, and then solving the problem of uneven distribution of nanoparticles in the atomized powder. The centrifugal motion of the centrifugal turntable 2 makes the mixed melt evenly distributed, and the jet airflow of the atomizing spray disc 3 further atomizes the mixed melt, ensuring that the nanoparticles are evenly distributed in the atomized droplets, thereby preparing a nanoparticle composite metal powder with uniformly distributed nanoparticles.

[0043] The crushing structure 4 can be realized by various structures.

[0044] For example, in some embodiments, see Figure 1-Figure 3 The crushing structure 4 includes a plurality of first discrete protrusion bands 401, a plurality of first annular grooves 402, a plurality of second discrete protrusion bands 403 and a plurality of second annular grooves 404. The first discrete protrusion band 401, the first annular groove 402, the second discrete protrusion band 403 and the second annular groove 404 are all coaxially arranged. The first discrete protrusion band 401 includes a plurality of first protrusions 4011 uniformly arranged along the circumferential direction, and the second discrete protrusion band 403 includes a plurality of second protrusions 4031 uniformly arranged along the circumferential direction. The first discrete protrusion band 401 and the first annular groove 402 are alternately arranged at intervals along the radial direction on the lower surface of the fixed crushing body 1 to form a first characteristic structure, and the second discrete protrusion band 403 and the second annular groove 404 are alternately arranged at intervals along the radial direction on the upper surface of the centrifugal turntable 2 to form a second characteristic structure. The first discrete protrusion band 401 and the second annular groove 404 are arranged opposite to each other up and down in a one-to-one correspondence, and the first annular groove 402 and the second discrete protrusion band 403 are arranged opposite to each other up and down in a one-to-one correspondence.

[0045] The crushing structure 4 includes a plurality of first discrete raised bands 401, a plurality of first annular grooves 402, a plurality of second discrete raised bands 403 and a plurality of second annular grooves 404. These structures are coaxially arranged and radially alternately arranged on the surfaces of the fixed crushing body 1 and the centrifugal turntable 2. Through the interaction of these structures, when the mixed melt moves in the interval space, these concave-convex structures will produce collision and shearing effects on the mixed melt, which can effectively mix and crush it, thereby solving the mixing and crushing problems of the mixed melt during movement.

[0046] Through the rotation of the centrifugal turntable 2, this structure can make the mixed melt subject to multiple collisions and shearing effects in the interval space, thereby achieving effective blending and crushing. Specifically, the raised portions of the first discrete raised band 401 and the second discrete raised band 403 will come into contact and collide with the mixed melt multiple times during its movement, thereby enhancing the blending effect. At the same time, the provision of the first annular groove 402 and the second annular groove 404 also increases the flow path of the mixed melt, causing it to be subjected to more shearing effects during its movement, thereby further improving the crushing effect. By providing alternatingly spaced concave-convex structures on the surfaces of the fixed crushing body 1 and the centrifugal turntable 2, effective blending and crushing of the mixed melt is achieved. Compared with the prior art, this technical solution can significantly improve the blending and crushing effects of the mixed melt without increasing additional energy consumption through the optimization of the structural design, solves the problem of uneven distribution of nanoparticles in the metal melt, and improves the quality and performance of nanoparticle composite metal powder.

[0047] The number of the first discrete protrusion band 401, the first annular groove 402, the second discrete protrusion band 403, and the second annular groove 404, the number of the first protrusions 4011 in each first discrete protrusion band 401, and the number of the second protrusions 4031 in each second discrete protrusion band 403 can be adjusted according to actual needs. The specific shapes of the first protrusion 4011 and the second protrusion 4031 can be set according to actual needs.

[0048] In order to avoid interference when the centrifugal turntable 2 rotates and ensure smooth passage of the mixed melt, a certain interval h is required between the first discrete protrusion band 401 and the corresponding second annular groove 404 and between the first annular groove 402 and the corresponding second discrete protrusion band 403 (see Figure 1 ), the interval h is preferably 0.5mm-3mm.

[0049] For example, in some embodiments, see Figure 4-Figure 6The crushing structure 4 includes a plurality of discrete groove bands 405 and a plurality of third annular grooves 406, the discrete groove bands 405 and the third annular grooves 406 are coaxially arranged, and the discrete groove bands 405 include a plurality of circular arc grooves 4051 uniformly arranged along the circumferential direction; at least one discrete groove band 405 and / or at least one third annular groove 406 are arranged on the lower surface of the fixed crushing body 1 to form a first characteristic structure, and at least one discrete groove band 405 and / or at least one third annular groove 406 are arranged on the upper surface of the centrifugal turntable 2 to form a first characteristic structure; each discrete groove band 405 is arranged opposite to a third annular groove 406 in the up-down direction, and at least one sphere 407 is arranged between each circular arc groove 4051 and the corresponding third annular groove 406, and the sphere 407 is partially located in the corresponding circular arc groove 4051 and the corresponding third annular groove 406 (such as Figure 4 as shown).

[0050] This design utilizes the rolling spheres 407 to fully blend and crush the mixed melt moving in the interval space, and in particular, can effectively crush agglomerated nanoparticles, thereby solving the problem of uneven distribution of nanoparticles in the atomized powder.

[0051] Among them, the discrete arc grooves 4051 are arranged to cooperate with the annular grooves (i.e., the third annular grooves 406). On the one hand, it can prevent the spheres 407 from hindering the rotation of the centrifugal turntable 2. On the other hand, the spheres 407 can be positioned at the position of the arc grooves 4051 to ensure the uniform distribution of the spheres 407 in the interval space, thereby ensuring that the mixed melt in all directions can be effectively blended and crushed evenly.

[0052] Among them, the number and distribution position of the discrete groove bands 405 and the third annular groove 406 can be adjusted according to actual needs, the number of arc grooves 4051 in each discrete groove band 405, and the number of spheres 407 in each arc groove 4051 can be adjusted according to actual needs.

[0053] For example Figure 5 and Figure 6 In the embodiment, all the discrete groove bands 405 are arranged on the lower surface of the fixed crushing body 1, and all the third annular grooves 406 are arranged on the upper surface of the centrifugal turntable 2. However, in fact, all the discrete groove bands 405 can also be arranged on the upper surface of the centrifugal turntable 2, and all the third annular grooves 406 can be arranged on the lower surface of the fixed crushing body 1; or, part of the discrete groove bands 405 can be arranged on the lower surface of the fixed crushing body 1, and another part of the discrete groove bands 405 can be arranged on the upper surface of the centrifugal turntable 2, and part of the third annular grooves 406 can be arranged on the lower surface of the fixed crushing body 1, and another part of the third annular grooves 406 can be arranged on the upper surface of the centrifugal turntable 2.

[0054] Optionally, the material of the spheres 407 is the same as that of the nanoparticles to avoid material contamination issues and ensure consistency of the mixing effect.

[0055] In this embodiment, the upper surface of the centrifugal turntable 2 is provided with a liquid falling zone 201, a second crushing zone 202 and a second flying zone 203, the liquid falling zone 201 is located at the center of the upper surface of the centrifugal turntable 2, the second flying zone 203 is located at the edge of the upper surface of the centrifugal turntable 2, and the second crushing zone 202 is located between the liquid falling zone 201 and the second flying zone 203; the lower surface of the fixed crushing body 1 is provided with a first crushing zone 102 and a first flying zone 103, the first flying zone 103 is located at the edge of the lower surface of the fixed crushing body 1, and the first crushing zone 102 is located between the through hole 101 and the first flying zone 103; the liquid falling zone 201 is opposite to the through hole 101, the second crushing zone 202 is opposite to the first crushing zone 102, and the second flying zone 203 is opposite to the first flying zone 103;

[0056] The crushing structure 4 is arranged between the first crushing zone 102 and the second crushing zone 202, and the first fly-off zone 103 and the second fly-off zone 203 are both smooth surfaces.

[0057] By setting the upper surface of the centrifugal turntable 2 and the lower surface of the fixed crushing body 1 to have different areas, these areas can effectively crush and evenly blend the mixed melt through corresponding designs. The liquid falling area 201 is used to receive the mixed melt injected from the through hole 101, the crushing area crushes and blends the mixed melt through the crushing structure 4, and the flying area ensures that the mixed melt flies out smoothly under the action of centrifugal force. Through this design, it can ensure that the mixed melt is fully crushed and evenly distributed on the centrifugal turntable 2, thereby solving the problem of uneven crushing of the mixed melt during the atomization process.

[0058] The liquid falling area 201 may be a straight structure or a concave structure.

[0059] The through hole 101 can be used for inserting the guide nozzle 600 of the nano-particle composite metal powder atomization device, or only for passing the mixed melt.

[0060] The first flying-off zone 103 and the second flying-off zone 203 may both be horizontal planes, thereby ensuring that the mixed melt maintains a stable motion trajectory when flying out, and reducing the deviation caused by gravity or other external forces.

[0061] The first flying-off area 103 and the second flying-off area 203 may also be arc surfaces that gradually bend downward from the inside to the outside (e.g. Figure 1As shown in FIG. 1 ), the normal distance between the first flying zone 103 and the second flying zone 203 is the same at any position. Thus, the guiding effect of the arc surface can be utilized to make the mixed melt receive a more uniform force when flying out, thereby further improving the uniformity of atomization. The design that the normal distance is the same at any position ensures that the distance between the two flying zones is consistent, thereby avoiding unstable flying of the melt due to uneven distance.

[0062] In some preferred embodiments, see Figure 3 The liquid drop area 201 is also provided with a plurality of third protrusions 204 protruding upward.

[0063] By providing a plurality of third protrusions 204 protruding upward in the liquid falling area 201, the distribution state of the mixed melt in the liquid falling area can be effectively changed, thereby promoting the uniform distribution of the mixed melt. These third protrusions 204 can disturb the mixed melt when it falls, so that the mixed melt is more evenly distributed on the centrifugal turntable 2, thereby improving the atomization effect and the uniform distribution of the nanoparticles in the metal powder. The third protrusions 204 disturb the mixed melt, so that it is more evenly distributed on the centrifugal turntable 2, and the agglomerated nanoparticles can also be broken up, thereby improving the atomization effect and the uniformity of the distribution of the nanoparticles in the metal powder.

[0064] Specifically, the third protrusions 204 protruding upward can be in different shapes, quantities and arrangements. For example, the third protrusions 204 can be conical, hemispherical or other suitable geometric shapes, and can be evenly distributed along the circumference or arranged in a specific pattern as required. By adjusting the height, quantity and spacing of the third protrusions 204, the distribution effect of the mixed melt can be further optimized.

[0065] Furthermore, the atomizing spray disc 3 can be arranged around the fixed crushing body 1, and the atomizing spray disc 3 can be provided with a LAVAL type or contraction type flow channel 301 to generate a high-speed airflow; the direction of the atomizing spray disc 3 spraying the airflow is preferably tilted downward and outward, so that the atomized metal droplets can be diffused to a larger range, reducing the probability of mutual collision between metal droplets, thereby reducing the generation of satellite balls. Among them, the angle A between the direction of the spraying airflow of the atomizing spray disc 3 and the vertical direction is preferably not greater than 15°, while ensuring the effective reduction of the generation of satellite balls, ensuring that the high-speed airflow and the mixed melt flying out of the centrifugal turntable 2 can generate sufficient impact to achieve reliable atomization, so that the size of the metal droplets meets the requirements.

[0066] Furthermore, when the second flight zone 203 is an arc surface that gradually bends downward from the inside to the outside, on the longitudinal section of the centrifugal turntable 2, the angle B between the tangent at the outer edge of the second flight zone 203 and the vertical direction is preferably not greater than 30°, so as to ensure that sufficient impact can be generated between the high-speed airflow and the mixed melt flying out of the centrifugal turntable 2 to achieve reliable atomization.

[0067] In some preferred embodiments, the fixed crushing body 1 is capable of heating the mixed melt.

[0068] By utilizing the heating function of the fixed crushing body 1, the appropriate temperature of the mixed melt can be maintained during the atomization process, thereby ensuring the fluidity and uniformity of the mixed melt. This heating function plays a certain role in solving the temperature control problem of the mixed melt. Specifically, the heating function of the fixed crushing body 1 can prevent the mixed melt from solidifying or decreasing in fluidity due to temperature drop during the atomization process, thereby improving the uniform distribution effect of the nanoparticles in the metal powder and improving the atomization effect of the atomizing spray disc 3 spraying the airflow.

[0069] There are many ways to realize the heating function of the fixed crushing body 1. For example, an electric heating device, such as a resistance wire heating device or an electric heating film heating device, can be set on the fixed crushing body 1. The fixed crushing body 1 can also be made of a conductive material, and the fixed crushing body 1 is used to heat the mixed melt by powering on. When in use, the fixed crushing body 1 is powered on to heat the fixed crushing body 1 itself, thereby heating the mixed melt.

[0070] refer to Figure 7 The present application provides a nano-particle composite metal powder atomization device, comprising a smelting chamber 200, an atomization chamber 300 arranged at the lower side of the smelting chamber 200, a smelting tongs pot 400 and a tundish 500 are arranged in the smelting chamber 200, a guide nozzle 600 is connected to the lower end of the tundish 500, and the guide nozzle 600 extends into the atomization chamber 300, the smelting tongs pot 400 is used to smelt a metal substrate to obtain a metal melt (the melt will be injected into the tundish 500); the smelting tongs pot 400 0 and / or the intermediate package 500 is also used to mix the metal melt and the nanoparticles to obtain a mixed melt; the atomizing chamber 300 is provided with the aforementioned atomizer 100 and a driving motor 700; the guide nozzle 600 extends into the through hole 101 of the atomizer 100 or is arranged above the atomizer 100 directly opposite to the through hole 101, and the guide nozzle 600 is used to output the mixed melt to the atomizer 100; the driving motor 700 is used to drive the centrifugal turntable 2 of the atomizer 100 to rotate.

[0071] A feeding mechanism for adding nanoparticles may be provided at the entrance of the smelting tongs 400 or the entrance of the tundish 500, and the nanoparticles are fed into the smelting tongs 400 or the tundish 500 through the feeding mechanism to be mixed with the molten metal substrate.

[0072] When the feeding mechanism inputs the nanoparticles into the smelting tongs 400, in order to improve the mixing uniformity, a stirring device can be provided in the smelting tongs 400 and / or the tundish 500; when the feeding mechanism inputs the nanoparticles into the tundish 500, a stirring device can be provided in the tundish 500. The stirring device can be a mechanical stirrer, an electromagnetic stirrer, an ultrasonic stirrer, etc.

[0073] The mixed melt is stirred by a stirring device before entering the guide nozzle 600. On the one hand, it can improve the distribution uniformity of the nanoparticles, thereby ultimately improving the distribution uniformity of the nanoparticles in the metal powder. On the other hand, it can reduce the probability of clogging of the guide nozzle 600 due to agglomeration of nanoparticles.

[0074] Furthermore, the nano-particle composite metal powder atomization equipment also includes a powder collecting device 800, and the powder collecting device 800 is used to collect the formed nano-particle composite metal powder.

[0075] Specifically, see Figure 7 The powder collecting device 800 includes a first powder collecting tank 801 arranged at the lower end of the atomization chamber 300, a cyclone separator 802 whose air inlet is connected to the atomization chamber 300, a second powder collecting tank 803 arranged at the lower end of the cyclone separator 802, a dust collector 804 whose air inlet is connected to the air outlet of the cyclone separator 802, a third powder collecting tank 805 arranged at the lower end of the dust collector 804, and an induced draft fan 806 connected to the air outlet of the dust collector 804.

[0076] During operation, coarse powder with large particle size mainly falls into the first powder collecting tank 801, and fine powder will enter the cyclone separator 802 with the air flow under the suction force provided by the induced draft fan 806. The cyclone separator 802 further separates the fine powder in the air flow, and the separated fine powder will fall into the second powder collecting tank 803, while the ultrafine powder will enter the dust collector 804 with the air flow for filtration, and the filtered ultrafine powder will fall into the third powder collecting tank 805, and the filtered air flow will be discharged to the atmosphere or the subsequent exhaust gas treatment system.

[0077] In summary, the nanoparticle composite metal powder atomization equipment and atomizer provided by the present application have at least the following advantages:

[0078] 1. Using the crushing structure 4, the nanoparticles are dispersed through impact, shearing and crushing, and the nanoparticle agglomerates are crushed to achieve uniform distribution of the nanoparticles in the metal melt;

[0079] 2. The crushing structure 4 is used to improve the relative slippage and uneven distribution of nanoparticles and metal substrate melt due to the inconsistent density when the centrifugal turntable 2 rotates at high speed;

[0080] 3. Reduce the wettability requirements between the surface material of the centrifugal turntable 2 and the metal substrate melt. The crushing structure 4 can be used to repeatedly impact the mixed melt so that the speed between the mixed melt and the centrifugal turntable 2 is synchronized, thereby improving the energy transfer efficiency of the centrifugal turntable 2 to the mixed melt.

[0081] 4. The preparation process of nanoparticle composite metal powder for additive manufacturing is short, the process cost is low, and the preparation time is short.

[0082] In this document, relational terms such as first and second, etc. are used merely to distinguish one entity or operation from another entity or operation, but do not necessarily require or imply any such actual relationship or order between these entities or operations.

[0083] The above description is only an embodiment of the present application and is not intended to limit the protection scope of the present application. For those skilled in the art, the present application may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. An atomizer, characterized in that: The invention comprises a coaxially arranged fixed crushing body (1), a centrifugal turntable (2) and an atomizing spray disc (3); the centrifugal turntable (2) is located below the fixed crushing body (1); a space is provided between the lower surface of the fixed crushing body (1) and the upper surface of the centrifugal turntable (2); the fixed crushing body (1) is provided with a through hole (101) which runs through the upper and lower parts and is connected to the space; the through hole (101) is used to inject a mixed melt formed by mixing nanoparticles and a metal melt into the space; the centrifugal turntable (2) is used to rotate to make the mixed melt perform centrifugal motion in the space and finally fly out from the edge of the centrifugal turntable (2); the atomizing spray disc (3) is used to spray an airflow to atomize the mixed melt flying out of the centrifugal turntable (2); The lower surface of the fixed crushing body (1) is provided with a first characteristic structure, the first characteristic structure comprising a convex structure and / or a concave structure, the upper surface of the centrifugal turntable (2) is provided with a second characteristic structure, the second characteristic structure comprising a convex structure and / or a concave structure, the first characteristic structure and the second characteristic structure are used to cooperate to form a crushing structure (4), and the crushing structure (4) is used to mix and crush the mixed melt moving in the interval space.

2. The atomizer according to claim 1, characterized in that The crushing structure (4) comprises a plurality of first discrete protrusion bands (401), a plurality of first annular grooves (402), a plurality of second discrete protrusion bands (403) and a plurality of second annular grooves (404); the first discrete protrusion band (401), the first annular groove (402), the second discrete protrusion band (403) and the second annular groove (404) are all coaxially arranged; the first discrete protrusion band (401) comprises a plurality of first protrusions (4011) uniformly arranged along the circumference; the second discrete protrusion band (403) comprises a plurality of second protrusions (4031) uniformly arranged along the circumference; 1); the first discrete raised bands (401) and the first annular grooves (402) are arranged alternately and spaced along the radial direction on the lower surface of the fixed crushing body (1) to form the first characteristic structure, and the second discrete raised bands (403) and the second annular grooves (404) are arranged alternately and spaced along the radial direction on the upper surface of the centrifugal turntable (2) to form the second characteristic structure; the first discrete raised bands (401) and the second annular grooves (404) are arranged opposite to each other in a one-to-one correspondence, and the first annular grooves (402) and the second discrete raised bands (403) are arranged opposite to each other in a one-to-one correspondence.

3. The atomizer according to claim 1, characterized in that The crushing structure (4) comprises a plurality of discrete groove bands (405) and a plurality of third annular grooves (406), wherein the discrete groove bands (405) and the third annular grooves (406) are coaxially arranged, and the discrete groove bands (405) comprise a plurality of circular arc grooves (4051) uniformly arranged along the circumferential direction; at least one of the discrete groove bands (405) and / or at least one of the third annular grooves (406) are arranged on the lower surface of the fixed crushing body (1) to form the first characteristic structure, and at least one of the discrete groove bands (405) And / or at least one of the third annular grooves (406) is arranged on the upper surface of the centrifugal turntable (2) to form the second characteristic structure; each of the discrete groove bands (405) is arranged opposite to a third annular groove (406) in the up and down direction, and at least one sphere (407) is arranged between each of the arc grooves (4051) and the corresponding third annular groove (406), and the sphere (407) is partially located in the corresponding arc groove (4051) and the corresponding third annular groove (406).

4. The atomizer according to claim 1, characterized in that The upper surface of the centrifugal turntable (2) is provided with a liquid falling zone (201), a second crushing zone (202) and a second flying zone (203); the liquid falling zone (201) is located at the center of the upper surface of the centrifugal turntable (2); the second flying zone (203) is located at the edge of the upper surface of the centrifugal turntable (2); and the second crushing zone (202) is located between the liquid falling zone (201) and the second flying zone (203); the lower surface of the fixed crushing body (1) is provided with a first crushing zone (202); a crushing zone (102) and a first flying-off zone (103), wherein the first flying-off zone (103) is located at the edge of the lower surface of the fixed crushing body (1), and the first crushing zone (102) is located between the through hole (101) and the first flying-off zone (103); the liquid falling zone (201) is opposite to the through hole (101), the second crushing zone (202) is opposite to the first crushing zone (102), and the second flying-off zone (203) is opposite to the first flying-off zone (103); The crushing structure (4) is arranged between the first crushing zone (102) and the second crushing zone (202), and the first fly-off zone (103) and the second fly-off zone (203) are both smooth surfaces.

5. The atomizer according to claim 4, characterized in that The first take-off area (103) and the second take-off area (203) are both horizontal planes; Alternatively, the first fly-off area (103) and the second fly-off area (203) are both arc surfaces that gradually bend downward from the inside to the outside, and the normal distance between the first fly-off area (103) and the second fly-off area (203) is the same at any position.

6. The atomizer according to claim 4, characterized in that The liquid drop area (201) is also provided with a plurality of third protrusions (204) protruding upwards.

7. The atomizer according to any one of claims 1 to 6, characterized in that: The fixed crushing body (1) is capable of heating the mixed melt.

8. The atomizer according to claim 7, characterized in that The fixed crushing body (1) is provided with an electric heating device; Alternatively, the fixed crushing body (1) is made of a conductive material, and the fixed crushing body (1) is used to generate heat by being energized to heat the mixed melt.

9. A nano-particle composite metal powder atomization device, comprising a smelting chamber (200), an atomization chamber (300) arranged at the lower side of the smelting chamber (200), a smelting tongs pot (400) and a tundish (500) arranged in the smelting chamber (200), a guide nozzle (600) connected to the lower end of the tundish (500), the guide nozzle (600) extending into the atomization chamber (300), the smelting tongs pot (400) being used for smelting a metal substrate to obtain a metal melt; characterized in that: The smelting tongs (400) and / or the tundish (500) are also used to mix the metal melt and the nanoparticles to obtain a mixed melt; the atomizing chamber (300) is provided with an atomizer (100) according to any one of claims 1 to 8 and a drive motor (700); the guide nozzle (600) extends into the through hole (101) of the atomizer (100) or is arranged above the atomizer (100) directly opposite to the through hole (101), and the guide nozzle (600) is used to output the mixed melt to the atomizer (100); the drive motor (700) is used to drive the centrifugal turntable (2) of the atomizer (100) to rotate.

10. The nano-particle composite metal powder atomization equipment according to claim 9, characterized in that: A stirring device is provided in the smelting tongs (400) and / or the tundish (500).

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