A melt atomization coating apparatus for metal powders and a method of operation thereof

Abstract

This invention discloses a melt atomization coating device for metal powder and its working method, relating to the field of additive manufacturing technology. It aims to solve the technical problem of satellite powder generation during melt atomization coating. The device includes an integrated ring seat, a guide tube, a nozzle, a fixed flow channel pre-gas chamber, a connecting block, a folded tube unit, a drive mechanism, and an adjustment mechanism. Through structural design of the integrated ring seat, guide tube, nozzle, and pre-gas channel system, the drive mechanism drives the connecting block to move synchronously radially and reciprocally. The pre-gas channel, composed of two folded tube units and through holes, undergoes changes in length and trajectory. The direction and angle of the turbulence-inducing sphere relative to the airflow continuously change, causing the ejected airflow to present a composite state. This disrupts the formation conditions of the recirculation zone, making it unstable and effectively suppressing satellite powder generation at its source, thus solving the technical problem of satellite powder generation during melt atomization coating.

Description

Technical Field

[0001] This invention relates to the field of additive manufacturing technology, and more specifically, to a melt atomization coating device for metal powder and its working method. Background Technology

[0002] Gas atomization powder production technology is one of the mainstream methods for producing metal powders for additive manufacturing. Its basic principle is to use high-speed inert gas to impact the molten metal flow, causing it to break up and condense into fine powder. In actual production, in order to achieve fine powder particles, it is usually necessary to use a supersonic gas jet (such as through a Laval nozzle) to strongly impact and break up the liquid flow.

[0003] However, this high-energy jet will inevitably form a stable reflux zone in the atomization chamber. The gas pressure in this reflux zone will continuously roll up the solidified fine powder particles, causing them to collide and adhere with the large droplets that have not yet fully solidified, eventually forming "satellite powder" defects. Satellite powder will significantly reduce the loose density, sphericity and flowability of the powder, seriously affecting the density and mechanical properties of the final part.

[0004] To address the aforementioned problems, existing technologies have proposed various improvement schemes. For example, optimizing the nozzle geometry to adjust the intensity and position of the recirculation zone, or introducing a second auxiliary airflow (such as a swirling or circulating flow) to interfere with the main airflow. However, most of these schemes are static structural designs, meaning the airflow field morphology remains unchanged during atomization, still resulting in a stable recirculation zone, thus making it difficult to fundamentally suppress satellite powder formation. Therefore, we propose a melt atomization coating device for metal powder and its operating method. Summary of the Invention

[0005] The purpose of this invention is to provide a melt atomization coating device for metal powder and its working method, so as to solve the technical problem of satellite powder being easily generated during the melt atomization coating process.

[0006] To solve the above-mentioned technical problems, the present invention provides the following technical solution: a method for molten atomization coating of metal powder, comprising the following steps: S1, Secret Refining: Add the metal powder and binder system to a mixer and mix for 30 minutes, then granulate evenly. S2, Injection Molding: The mixed raw material is injected into a mold and injection molded into a bar with a diameter of 70mm or a wire with a diameter of 1.75mm. S3, Melting and Atomization: The rod or wire obtained in step S2 is fed into a melt atomization coating device. The rod or wire is heated by electrode induction to form a liquid flow. The liquid flow is then blown into spherical coating powder by high-pressure inert gas. S4, Ball Mill: The powder obtained by atomization is added to an agate ball mill for ball milling to break up agglomerated particles and complete spheroidization. S5, High-speed mixing: Add the ball-milled powder to a high-speed mixer and mix the binder components that cannot be dissolved and precipitated at a speed of 2000-3000 rpm; S6, Grading: The mixed powder is fed into a fluidized bed air jet mill for classification, and finished powders in two particle size ranges of 20-63μm and 25-106μm are sieved out.

[0007] In step S3, the melt atomization coating equipment includes a melting chamber and an atomization chamber arranged vertically, and also includes an integrated ring seat. The integrated ring seat is fixed to the top of the atomization chamber, and a guide pipe is fixed inside the integrated ring seat. The top end of the guide pipe is connected to the bottom end of the melting chamber. A nozzle is fixed to the bottom end of the integrated ring seat, and several fixed flow channels are evenly opened along the circumference of the nozzle. A pre-flow channel system is provided inside the integrated ring seat. The pre-flow channel system includes a pre-gas chamber and several connecting blocks. The input end of the pre-gas chamber is connected to the output end of an external gas source mechanism, and the several connecting blocks are respectively opposite to several fixed flow channels. The fixed flow channel is located below the pre-air chamber. A through hole is provided in the connecting block, and a transverse sliding groove is provided on the connecting block. Both ends of the transverse sliding groove are slidably provided with blocks. Both ends of the through hole are provided with folded tube units. Several interference flow balls are uniformly fixed on the inner surface of the folded tube units. The two folded tube units are respectively connected to the pre-air chamber and the fixed flow channel. The integrated ring seat is also provided with a driving mechanism and an adjusting mechanism in an upper and lower structure. The driving mechanism is used to drive several connecting blocks to move radially back and forth synchronously, and the adjusting mechanism is used to adjust the positions of several blocks synchronously. This invention, through the structural design of the integrated ring seat, guide tube, nozzle, and pre-flow channel system, allows high-pressure gas to enter through the pre-flow chamber, flow sequentially through the folded tube unit and through the through hole, and then be ejected from the fixed flow channel of the nozzle. The drive mechanism drives the connecting block to move radially and reciprocally synchronously, causing the folded tube unit to periodically expand and contract. At the same time, the turbulence-inducing spheres uniformly fixed on the inner surface of the folded tube unit create turbulence in the flowing gas. When the folded tube unit bends, the length and trajectory of the pre-flow channel formed by the two folded tube units and the through hole change. The direction and angle of the turbulence-inducing spheres relative to the airflow continuously change, causing the ejected airflow to exhibit a composite state of "dynamic change in macroscopic spatial distribution" and "continuous disturbance of microscopic turbulence," disrupting the formation conditions of the recirculation zone and making it unable to exist stably. This effectively suppresses the generation of satellite powder from the source and solves the technical problem of easy generation of satellite powder during melt atomization and coating.

[0008] Preferably, the integrated ring seat has a plurality of radial grooves in the middle relative to the positions of the plurality of fixed flow channels, the plurality of radial grooves are connected by a rotating ring groove A, a rotating ring groove B is formed above the rotating ring groove A, the inner surface of the rotating ring groove B is connected by a circular groove, the top of the integrated ring seat has an installation cavity, both ends of the radial grooves have movable cavities, a fan-shaped vertical sliding cavity is formed in the gap between two adjacent radial grooves, both ends of the radial grooves have circumferential grooves connected to the vertical sliding cavities, the bottom ends of the plurality of vertical sliding cavities are connected by a rotating ring groove C, the surface of the rotating ring groove C is connected by a cavity, and the surface of the integrated ring seat has a groove relative to the cavity.

[0009] Preferably, the fixed flow channel includes a vertical hole A at the top of the nozzle and an oblique hole at the bottom of the fixed flow channel. The central axis of the oblique hole intersects with the central axis of the guide tube, and the oblique hole and the vertical hole A are connected through an arc-shaped hole.

[0010] Preferably, the pre-air chamber includes an annular cavity formed within the integrated ring seat. The bottom end of the annular cavity has a plurality of vertical holes B formed relative to the vertical hole A. The plurality of vertical holes B are respectively connected to a plurality of movable cavities located above. The integrated ring seat has an input hole that communicates with the annular cavity. The axis of the input hole is tangent to the inner wall of the annular cavity. Threaded grooves are formed at the top end of the vertical hole A, both ends of the through hole, and the bottom end of the vertical hole B.

[0011] Preferably, the connecting block has a connecting shaft fixed at the end away from the guide pipe, and the connecting shaft at the end away from the connecting block passes through the rotating annular groove A and is fixed with a movable ball block A; the stop block has a trapezoidal structure at the end near the through hole, and a connecting rod is fixed at the end of the stop block away from the through hole, and the connecting rod at the end away from the through hole passes through the circumferential sliding groove and is fixed with a movable ball block B.

[0012] Preferably, the folded tube unit includes a folded metal tube with a corrugated cross-section. Several folded metal tubes are respectively disposed in several movable cavities. Both ends of the folded metal tube are fixedly provided with connecting rings. The end of the connecting ring away from the folded metal tube is rotatably connected to a threaded ring. Several threaded rings are respectively threadedly connected to several threaded grooves. In this case, the interference flow ball is uniformly fixed on the jet flow channel formed by the inner surfaces of the folded metal tube, the two connecting rings, and the two threaded rings.

[0013] Preferably, the driving mechanism includes a ring block, a gear ring, a gear, and a motor. The ring block is rotatably disposed within the rotating annular groove A. A sealed reciprocating guide groove is formed within the ring block. An annular through groove communicating with the sealed reciprocating guide groove is formed on the inner surface of the ring block. Several connecting shafts are movably connected to the annular through groove. Several movable ball blocks A are movably connected to the sealed reciprocating guide groove. The gear ring is disposed within the rotating annular groove B. The bottom end of the gear ring is rotatably connected to the rotating annular groove B via a rotating ring A. The bottom end of the rotating ring A passes through the rotating annular groove A and is fixedly connected to the top end of the ring block. The gear is rotatably disposed within the circular groove. The motor is fixedly disposed within the mounting cavity. The top end of the central shaft of the gear passes through the mounting cavity and is fixedly connected to the output shaft of the motor. The sealed reciprocating guide groove is composed of several V-shaped grooves arranged in an annular, equally spaced structure with their ends connected.

[0014] Preferably, the adjusting mechanism includes a worm gear, a worm, several sector blocks, and several circumferential sliding plates; the worm gear is disposed on the rotating annular groove C, and the bottom end of the worm gear is rotatably connected to the bottom end of the rotating annular groove C through a rotating ring B; a threaded guide groove is provided inside the worm gear; the worm is rotatably disposed in the cavity; one end of the worm near the groove passes through the groove and is fixedly provided with an adjusting screw block; several sector blocks are slidably disposed in several vertical sliding cavities; several partial threaded strips are fixedly provided on the outer surface of the sector blocks in a linear, equally spaced structure; several partial threaded strips are evenly fitted with the threaded guide grooves; both sides of the top of the sector blocks are inclined; inclined guide grooves are provided on the inclined surfaces on both sides of the top of the sector blocks; several circumferential sliding plates are slidably disposed in several circumferential sliding grooves; several circumferential sliding plates are connected to several movable ball blocks B; an inclined slider is fixedly provided at one end of the circumferential sliding plate near the inclined guide groove; the inclined slider is slidably connected to the inclined guide groove.

[0015] Preferably, the circumferential sliding plate has a transverse groove that is movably connected to the connecting rod at one end near the movable ball block B, and a wave groove is formed at the other end of the transverse groove away from the movable ball block B, with the movable ball block B being movably connected to the wave groove.

[0016] The beneficial effects of this invention are: 1. This invention, through the structural design of the integrated ring seat, guide tube, nozzle, and pre-flow channel system, allows high-pressure gas to enter through the pre-flow chamber, flow sequentially through the folded tube unit and through the through hole, and then be ejected from the fixed flow channel of the nozzle. The drive mechanism drives the connecting block to move radially and reciprocally in sync, causing the folded tube unit to periodically expand and contract. At the same time, the turbulence-inducing spheres uniformly fixed on the inner surface of the folded tube unit cause the flowing gas to generate turbulence. When the folded tube unit bends, the length and trajectory of the pre-flow channel formed by the two folded tube units and the through hole change. The direction and angle of the turbulence-inducing spheres relative to the airflow continuously change, causing the ejected airflow to exhibit a composite state of "dynamic change in macroscopic spatial distribution" and "continuous disturbance of microscopic turbulence," which disrupts the formation conditions of the recirculation zone and makes it unable to exist stably. This effectively suppresses the generation of satellite powder from the source and solves the technical problem of easy generation of satellite powder during melt atomization coating.

[0017] 2. This invention, through the structural design of the adjustment mechanism, allows the operator to preset the fixed gap size at the through hole according to the material characteristics of the metal powder to be atomized. The operator manually rotates the adjusting screw to drive the worm gear to rotate, and the worm gear drives the worm wheel and the threaded guide groove to rotate in the rotating ring groove C. The threaded guide groove is in movable cooperation with part of the threaded strip on the sector block, so that when the worm wheel rotates, the threaded guide groove pushes the sector block to slide up and down in the vertical sliding cavity. The inclined guide groove at the top of the sector block is in sliding cooperation with the inclined slider on the circumferential slide plate, converting the vertical movement of the sector block into the horizontal movement of the circumferential slide plate in the circumferential sliding groove. This causes the circumferential slide plate to drive the stop block to move through the movable ball block B and the connecting rod, so that the gap channel size between the two stop blocks changes, realizing the synchronous and rapid adjustment of the position of several stop blocks to adapt to the atomization requirements of metal powders of different materials.

[0018] 3. Through further design of the circumferential sliding plate, this invention enables the stop block to move relative to the wave groove by driving the movable ball block B through the connecting rod when the connecting block moves radially back and forth. This causes the two corresponding stop blocks on the same connecting block to move back and forth in opposite directions. As atomization process, the gap channel size between the two stop blocks changes back and forth, causing the airflow flowing through the through hole to have periodic velocity pulsations superimposed on the spatial direction change, forming a composite airflow state. This further disrupts the stable structure of the return zone, preventing the return zone from forming a continuous powder encapsulation path, thereby further suppressing the generation of satellite powder. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the overall structure of the present invention.

[0020] Figure 2 This is a schematic cross-sectional view of the overall structure of the present invention.

[0021] Figure 3 This is a cross-sectional structural diagram of the integrated ring seat and fixed flow channel of the present invention.

[0022] Figure 4 This is a schematic diagram of the disassembled structure of the integrated ring seat of the present invention.

[0023] Figure 5 for Figure 4 An enlarged schematic diagram of the structure of part A.

[0024] Figure 6 This is a partial structural cross-sectional schematic diagram of the present invention.

[0025] Figure 7 This is a cross-sectional structural diagram of the connecting block, folding tube unit, driving mechanism, and adjusting mechanism of the present invention.

[0026] Figure 8 This is a cross-sectional structural diagram of the connecting block and folded tube unit of the present invention.

[0027] Figure 9 This is a cross-sectional structural diagram of the connecting block, circumferential sliding plate, and inclined sliding block of the present invention.

[0028] Figure 10 This is a schematic diagram of the adjustment mechanism of the present invention.

[0029] Figure 11 This is a partial structural breakdown diagram of the adjustment mechanism of the present invention.

[0030] Explanation of the labels in the diagram: 1. Integrated ring seat; 2. Guide tube; 3. Nozzle; 4. Fixed flow channel; 5. Pre-air chamber; 6. Connecting block; 7. Folded tube unit; 8. Drive mechanism; 9. Adjustment mechanism; 11. Radial groove; 12. Rotary annular groove A; 13. Rotary annular groove B; 14. Circular groove; 15. Mounting cavity; 16. Movable cavity; 17. Vertical sliding cavity; 18. Circumferential groove; 19. Rotary annular groove C; 110. Cavity; 111. Groove; 41. Vertical hole A; 42. Angled hole; 43. Arc-shaped hole; 51. Annular cavity; 52. Vertical hole B; 61. Through hole; 62. Transverse groove; 63. Stop block; 64. Coupling; 65. Movable ball block A; 66. Connecting rod; 67. Movable ball block B; 70. Turbulence-inducing sphere; 71. Folded metal tube; 72. Connecting ring; 73. Threaded ring; 81. Ring block; 82. Sealed reciprocating guide groove; 83. Circular through groove; 84. Gear ring; 85. Rotary ring A; 86. Gear; 87. Motor; 90. Adjusting screw block; 91. Worm gear; 92. Rotary ring B; 93. Threaded guide groove; 94. Worm; 95. Sector block; 96. Partial threaded strip; 97. Angled guide groove; 98. Circumferential sliding plate; 99. Angled slider; 981. Horizontal groove; 982. Wave groove. Detailed Implementation

[0031] like Figures 1 to 11 As shown, the present invention relates to a melt atomization coating device for metal powder and its working method, comprising the following steps: S1, Secret Refining: Add the metal powder and binder system to a mixer and mix for 30 minutes, then granulate evenly. S2, Injection Molding: The mixed raw material is injected into a mold and injection molded into a bar with a diameter of 70mm or a wire with a diameter of 1.75mm. S3, Melting and Atomization: The rod or wire obtained in step S2 is fed into a melt atomization coating device. The rod or wire is heated by electrode induction to form a liquid flow. The liquid flow is then blown into spherical coating powder by high-pressure inert gas. S4, Ball Mill: The powder obtained by atomization is added to an agate ball mill for ball milling to break up agglomerated particles and complete spheroidization. S5, High-speed mixing: Add the ball-milled powder to a high-speed mixer and mix the binder components that cannot be dissolved and precipitated at a speed of 2000-3000 rpm; S6, Grading: The mixed powder is fed into a fluidized bed air jet mill for classification, and finished powders in two particle size ranges of 20-63μm and 25-106μm are sieved out.

[0032] In step S3, the melt atomization coating equipment includes a melting chamber and an atomization chamber arranged in an upper and lower structure, such as... Figure 1 As shown, it also includes an integrated ring seat 1, which is fixed at the top of the atomizing chamber. A guide pipe 2 is fixed inside the integrated ring seat 1. The top of the guide pipe 2 is connected to the bottom of the melting chamber. A nozzle 3 is fixed at the bottom of the integrated ring seat 1. Several fixed flow channels 4 are evenly opened along the circumference of the nozzle 3. In embodiments of the present invention, such as Figure 2 and Figure 8As shown, the integrated ring seat 1 is equipped with a front flow channel system, which includes a front air chamber 5 and several connecting blocks 6. The input end of the front air chamber 5 is connected to the output end of the external air source mechanism. The several connecting blocks 6 are respectively positioned below the front air chamber 5 relative to several fixed flow channels 4. The connecting blocks 6 have through holes 61 and transverse sliding grooves 62. Both ends of the transverse sliding grooves 62 are slidably equipped with stops 63. Both ends of the through holes 61 are equipped with folded tube units 7. Several interference flow balls 70 are uniformly fixed on the inner surface of the folded tube units 7. The two folded tube units 7 are respectively connected to the front air chamber 5 and the fixed flow channels 4. The integrated ring seat 1 is also equipped with a drive mechanism 8 and an adjustment mechanism 9 in an upper and lower structure. The drive mechanism 8 is used to drive the several connecting blocks 6 to move radially back and forth synchronously, and the adjustment mechanism 9 is used to adjust the positions of the several stops 63 synchronously. This invention, through the structural design of the integrated ring seat 1, guide tube 2, nozzle 3, and pre-flow channel system, allows high-pressure gas to enter through the pre-flow chamber 5, flow sequentially through the folded tube unit 7 and through hole 61, and then be ejected from the fixed flow channel 4 of the nozzle 3. The driving mechanism 8 drives the connecting block 6 to move radially and reciprocally in sync, causing the folded tube unit 7 to periodically expand and contract. At the same time, the turbulence-inducing spheres 70 uniformly fixed on the inner surface of the folded tube unit 7 generate turbulence in the flowing gas. When the folded tube unit 7 bends, the length and trajectory of the pre-flow channel formed by the two folded tube units 7 and the through hole 61 change. The direction and angle of the turbulence-inducing spheres 70 relative to the airflow continuously change, causing the ejected airflow to exhibit a composite state of "dynamic change in macroscopic spatial distribution" and "continuous disturbance of microscopic turbulence," disrupting the formation conditions of the return zone and making it unable to exist stably. This effectively suppresses the generation of satellite powder from the source and solves the technical problem of easy generation of satellite powder during melt atomization coating.

[0033] In embodiments of the present invention, such as Figure 3 , Figure 4 and Figure 5 As shown, the integrated ring seat 1 has several radial grooves 11 at the middle position relative to several fixed flow channels 4. The radial grooves 11 are connected by a rotating ring groove A12. A rotating ring groove B13 is provided above the rotating ring groove A12. A circular groove 14 is provided on the inner surface of the rotating ring groove B13. An installation cavity 15 is provided at the top of the integrated ring seat 1. Movable cavities 16 are provided at both ends of the radial grooves 11. A fan-shaped vertical sliding cavity 17 is provided in the gap between two adjacent radial grooves 11. A circumferential groove 18 is provided at both ends of the radial grooves 11 and is connected to the vertical sliding cavity 17. The bottom ends of several vertical sliding cavities 17 are connected by a rotating ring groove C19. A cavity 110 is provided on the surface of the rotating ring groove C19. A groove 111 is provided on the surface of the integrated ring seat 1 at the position relative to the cavity 110.

[0034] In embodiments of the present invention, such as Figure 3As shown, the fixed flow channel 4 includes a vertical hole A41 at the top of the nozzle 3 and an oblique hole 42 at the bottom of the fixed flow channel 4. The central axis of the oblique hole 42 intersects the central axis of the guide tube 2, and the oblique hole 42 and the vertical hole A41 are connected through an arc-shaped hole 43. The fixed flow channel 4 of the present invention is composed of the vertical hole A41, the arc-shaped hole 43, and the oblique hole 42 connected in sequence. The central axis of the oblique hole 42 intersects the central axis of the guide tube 2, so that the ejected gas impacts the molten metal flow at a fixed angle, ensuring a constant atomization direction.

[0035] In embodiments of the present invention, such as Figure 4 As shown, the pre-air chamber 5 includes an annular cavity 51 opened in the integrated ring seat 1. The bottom end of the annular cavity 51 has a plurality of vertical holes B52 opened at a position opposite to the vertical hole A41. The plurality of vertical holes B52 are respectively connected to a plurality of movable cavities 16 located above. The integrated ring seat 1 has an input hole 53 that communicates with the annular cavity 51. The axis of the input hole 53 is tangent to the inner wall of the annular cavity 51. Threaded grooves are opened at the top end of the vertical hole A41, both ends of the through hole 61 and the bottom end of the vertical hole B52. This invention sets the axis of the input hole 53 to be tangential to the inner wall of the annular cavity 51, allowing high-pressure gas to enter the annular cavity 51 tangentially. A rotating airflow is formed in the annular cavity 51, and the gas is evenly distributed in the circumferential direction. Then, it is evenly distributed to each folded tube unit 7 through the vertical hole B52. This tangential air intake structure solves the problem of uneven airflow distribution caused by traditional radial air intake and ensures the consistency of air intake in each fixed flow channel 4. The threaded grooves opened at the top of the vertical hole A41, both ends of the through hole 61, and the bottom of the vertical hole B52 are used to connect with the threaded ring 73 of the folded tube unit 7, so as to realize the quick loading and unloading of the folded tube unit 7.

[0036] In embodiments of the present invention, such as Figure 8 and Figure 9 As shown, a connecting shaft 64 is fixed at the end of the connecting block 6 away from the guide pipe 2. The end of the connecting shaft 64 away from the connecting block 6 passes through the rotating annular groove A12 and is fixed with a movable ball block A65. The end of the stop block 63 near the through hole 61 has a trapezoidal structure. A connecting rod 66 is fixed at the end of the stop block 63 away from the through hole 61. The end of the connecting rod 66 away from the through hole 61 passes through the circumferential sliding groove 18 and is fixed with a movable ball block B67. Through the above arrangement, the gap channel between the two stop blocks 63 forms a fixed narrow opening and a diffusion region, causing the airflow to generate local acceleration, diffusion, and backflow effects at the through hole 61, thereby enhancing the micro-disturbance of the airflow.

[0037] In embodiments of the present invention, such as Figure 5As shown, the folded tube unit 7 includes a folded metal tube 71 with a corrugated cross section. Several folded metal tubes 71 are respectively disposed in several movable cavities 16. Both ends of the folded metal tube 71 are fixedly provided with connecting rings 72. The end of the connecting ring 72 away from the folded metal tube 71 is rotatably connected to a threaded ring 73. Several threaded rings 73 are respectively threadedly connected to several threaded grooves. If the interference flow ball block 70 is uniformly fixed on the jet flow channel formed by the inner surfaces of the folded metal tube 71, the two connecting rings 72 and the two threaded rings 73.

[0038] In embodiments of the present invention, such as Figure 6 and Figure 7 As shown, the drive mechanism 8 includes a ring block 81, a gear ring 84, a gear 86, and a motor 87. The ring block 81 is rotatably disposed within a rotating annular groove A12. A sealed reciprocating guide groove 82 is formed within the ring block 81. An annular through groove 83 communicating with the sealed reciprocating guide groove 82 is formed on the inner surface of the ring block 81. Several connecting shafts 64 are movably connected to the annular through groove 83. Several movable ball blocks A65 are movably connected to the sealed reciprocating guide groove 82. The gear ring 84 is disposed within the rotating annular groove B13. Inside, the bottom end of the gear ring 84 is rotatably connected to the rotating annular groove B13 via a rotating ring A85. The bottom end of the rotating ring A85 passes through the rotating annular groove A12 and is fixedly connected to the top end of the ring block 81. The gear 86 is rotatably disposed in the circular groove 14. The motor 87 is fixedly disposed in the mounting cavity 15. The top end of the central shaft of the gear 86 passes through the mounting cavity 15 and is fixedly connected to the output shaft of the motor 87. The sealed reciprocating guide groove 82 is composed of several V-shaped grooves arranged in a ring with equal spacing, with their ends connected. Through the structural design of the drive mechanism 8, the present invention enables the output shaft of the motor 87 to rotate, the gear 86 to rotate, and the gear 86 to drive the gear ring 84 to rotate. The gear ring 84 drives the ring block 81 to rotate synchronously in the rotating annular groove A12 via the rotating ring A85. This causes the sealed reciprocating guide groove 82 to rotate relative to several movable ball blocks A65, and causes the movable ball blocks A65 to drive the connecting block 6 to move synchronously radially back and forth via the connecting shaft 64.

[0039] In embodiments of the present invention, such as Figure 10 and Figure 11As shown, the adjusting mechanism 9 includes a worm gear 91, a worm 94, several sector blocks 95, and several circumferential sliding plates 98. The worm gear 91 is mounted on a rotating annular groove C19, and the bottom end of the worm gear 91 is rotatably connected to the bottom end of the rotating annular groove C19 via a rotating ring B92. A threaded guide groove 93 is provided inside the worm gear 91. The worm 94 is rotatably mounted in the cavity 110, and one end of the worm 94 near the groove 111 is inserted into the groove 111 and fixed with an adjusting screw block 90. ​​Several sector blocks 95 are slidably mounted in several vertical sliding cavities 17. The surface has a linear, evenly spaced structure with several threaded strips 96 fixedly attached. The threaded strips 96 are movably fitted with uniformly threaded guide grooves 93. The top of the fan-shaped block 95 has a sloping structure on both sides. Inclined guide grooves 97 are opened on the sloping surfaces on both sides of the top of the fan-shaped block 95. Several circumferential sliding plates 98 are slidably disposed in several circumferential sliding grooves 18. The several circumferential sliding plates 98 are connected to several movable ball blocks B67. An inclined slider 99 is fixedly attached to one end of the circumferential sliding plate 98 near the inclined guide groove 97. The inclined slider 99 is slidably connected to the inclined guide groove 97. This invention, through the structural design of the adjustment mechanism 9, allows the operator to preset the fixed gap size at the through hole 61 according to the material characteristics of the metal powder to be atomized. The operator manually rotates the adjustment screw block 90 to drive the worm gear 94 to rotate. The worm gear 94 drives the worm wheel 91 and the threaded guide groove 93 to rotate within the rotating ring groove C19. The threaded guide groove 93 is in movable engagement with a portion of the threaded strip 96 on the sector block 95. When the worm wheel 91 rotates, the threaded guide groove 93 pushes the sector block 95 to slide up and down within the vertical sliding cavity 17. The inclined guide groove 97 at the top of the sector block 95 is in sliding engagement with the inclined slider 99 on the circumferential slide plate 98, converting the vertical movement of the sector block 95 into the horizontal movement of the circumferential slide plate 98 within the circumferential sliding groove 18. This causes the circumferential slide plate 98 to move the stop block 63 through the movable ball block B67 and the connecting rod 66, changing the gap channel size between the two stop blocks 63. This achieves synchronous and rapid adjustment of the positions of several stop blocks 63 to adapt to the atomization requirements of metal powders of different materials.

[0040] In embodiments of the present invention, such as Figure 9 As shown, the circumferential sliding plate 98 has a transverse groove 981 at the end near the movable ball block B67, which is movably connected to the connecting rod 66. A wave groove 982 is formed at the end of the transverse groove 981 away from the movable ball block B67, and the movable ball block B67 is movably connected to the wave groove 982. Through further design of the circumferential sliding plate 98, when the connecting block 6 moves radially back and forth, the stop block 63 drives the movable ball block B67 to move relative to the wave groove 982 via the connecting rod 66. This causes the two corresponding stop blocks 63 on the same connecting block 6 to move back and forth in opposite directions. During atomization, the gap between the two stop blocks 63 changes repeatedly, causing the airflow through the through hole 61 to undergo periodic velocity pulsations on top of spatial directional changes, forming a composite airflow state. This further disrupts the stable structure of the recirculation zone, preventing the formation of a continuous powder path in the recirculation zone, thereby further suppressing the generation of satellite powder.

[0041] Working principle: This embodiment provides a melt atomization coating device for metal powder and its working method. When in use, high-pressure inert gas enters the annular cavity 51 tangentially through the input hole 53, forming a rotating airflow in the annular cavity 51. After the gas is evenly distributed along the circumferential direction, it is distributed to the corresponding folded tube unit 7 through each vertical hole B52. After the gas flows through the upper folded tube unit 7, the through hole 61 of the connecting block 6, and the lower folded tube unit 7 in sequence, it enters the fixed flow channel 4 of the nozzle 3 and finally sprays out from the inclined hole 42 at a fixed angle, impacting the molten metal flow from the guide tube 2. During atomization, motor 87 drives gear 86 to rotate, which in turn drives ring block 81 to rotate continuously within rotating ring groove A12 via gear ring 84 and rotating ring A85. The sealed reciprocating guide groove 82 within ring block 81 is formed by connecting the head and tail of V-shaped grooves. Movable ball block A65 slides under the constraint of the V-shaped groove, and drives connecting block 6 to perform periodic radial reciprocating motion along radial slide groove 11 via connecting shaft 64. When connecting block 6 reciprocates, folded tube unit 7 performs periodic expansion and contraction. The length and trajectory of the front channel formed by two folded tube units 7 and through hole 61 change, causing the airflow direction distribution before entering fixed flow channel 4 to continuously change, thereby achieving dynamic modulation of macroscopic spatial distribution. Meanwhile, the turbulence-inducing spheres 70 uniformly fixed on the inner surface of the folded tube unit 7 cause turbulence in the flowing gas. When the folded tube unit 7 bends, the direction and angle of the turbulence-inducing spheres 70 relative to the airflow continuously change, causing the turbulence intensity to dynamically increase with the bending state, forming a continuous disturbance of micro-turbulence. In addition, when the connecting block 6 reciprocates, the connecting rod 66 drives the movable ball block B67 to move relative to the wave groove 982, causing the two corresponding blocks 63 on the same connecting block 6 to move back and forth in opposite directions. The size of the gap channel at the through hole 61 changes periodically, and the velocity pulsation is superimposed on the spatial modulation, further enriching the micro-pulsation component of the airflow. The combined effect of the above three factors results in the airflow that is finally ejected from the inclined hole 42 exhibiting a composite state of "dynamic changes in macroscopic spatial distribution" and "continuous disturbance of microscopic turbulence". This composite airflow continuously disrupts the stable structure of the recirculation zone in the atomization chamber, preventing the recirculation zone from forming a continuous powder entrainment path. Small powder particles cannot be stably entrained and transported to the large droplets, thus effectively suppressing the generation of satellite powder from the source. According to the material characteristics of the metal powder to be atomized, the operator can manually rotate the adjusting screw 90 in advance. Through the transmission of the worm 94, worm wheel 91, sector block 95 and circumferential slide plate 98, the initial position of each stop block 63 is adjusted synchronously, and the size of the fixed gap at the preset through hole 61 is set to meet the atomization requirements of metal powders of different materials.

[0042] The embodiments disclosed in this invention are preferred embodiments, but are not limited thereto. Those skilled in the art can easily understand the spirit of this invention based on the above embodiments and make different extensions and variations, but as long as they do not depart from the spirit of this invention, they are all within the protection scope of this invention.

Claims

1. A method for molten atomization coating of metal powder, characterized in that, Includes the following steps: S1, Secret Refining: Add the metal powder and binder system to a mixer and mix for 30 minutes, then granulate evenly. S2, Injection Molding: The mixed raw material is injected into a mold and injection molded into a bar with a diameter of 70mm or a wire with a diameter of 1.75mm. S3, Melting and Atomization: The rod or wire obtained in step S2 is fed into a melt atomization coating device. The rod or wire is heated by electrode induction to form a liquid flow. The liquid flow is then blown into spherical coating powder by high-pressure inert gas. S4, Ball Mill: The powder obtained by atomization is added to an agate ball mill for ball milling to break up agglomerated particles and complete spheroidization. S5, High-speed mixing: Add the ball-milled powder to a high-speed mixer and mix the binder components that cannot be dissolved and precipitated at a speed of 2000-3000 rpm; S6, Grading: The mixed powder is fed into a fluidized bed air jet mill for classification, and finished powders in two particle size ranges of 20-63μm and 25-106μm are sieved out.

2. The melt atomization coating method for metal powder according to claim 1, wherein in step S3, the melt atomization coating equipment comprises a melting chamber and an atomization chamber arranged in an upper and lower structure, characterized in that, It also includes an integrated ring seat (1), which is fixed at the top of the atomizing chamber. A guide pipe (2) is fixed inside the integrated ring seat (1). The top of the guide pipe (2) is connected to the bottom of the melting chamber. A nozzle (3) is fixed at the bottom of the integrated ring seat (1). Several fixed flow channels (4) are evenly opened along the circumference of the nozzle (3). The integrated ring seat (1) is provided with a front flow channel system, which includes a front air chamber (5) and several connecting blocks (6). The input end of the front air chamber (5) is connected to the output end of an external air source mechanism. Several connecting blocks (6) are respectively positioned below the front air chamber (5) relative to several fixed flow channels (4). A through hole (61) is opened in the connecting block (6), and a transverse sliding groove (62) is opened on the connecting block (6). Both ends of the transverse sliding groove (62) are slidably provided with a stop block (63). Both ends of the through hole (61) are provided with folded tube units (7), and the inner surface of the folded tube unit (7) is uniformly fixed with a few turbulent flow balls (70). The two folded tube units (7) are respectively connected to the front air chamber (5) and the fixed flow channel (4). The integrated ring seat (1) is also provided with a driving mechanism (8) and an adjusting mechanism (9) in an upper and lower structure. The driving mechanism (8) is used to drive several connecting blocks (6) to move radially and reciprocally in sync. The adjusting mechanism (9) is used to adjust the position of several stops (63) in sync.

3. The melt atomization coating equipment according to claim 2, characterized in that, The integrated ring seat (1) has several radial grooves (11) in the middle relative to several fixed flow channels (4). The radial grooves (11) are connected by a rotating ring groove A (12). A rotating ring groove B (13) is provided above the rotating ring groove A (12). A circular groove (14) is provided on the inner surface of the rotating ring groove B (13). An installation cavity (15) is provided at the top of the integrated ring seat (1). Movable cavities (16) are provided at both ends of the radial grooves (11). A fan-shaped vertical sliding cavity (17) is provided in the gap between two adjacent radial sliding grooves (11). Both ends of the radial sliding groove (11) are provided with circumferential sliding grooves (18) that communicate with the vertical sliding cavity (17). The bottom ends of several vertical sliding cavities (17) are connected by a rotating ring groove C (19). A cavity (110) is provided on the surface of the rotating ring groove C (19). A groove (111) is provided on the surface of the integrated ring seat (1) relative to the cavity (110).

4. The melt atomization coating equipment according to claim 3, characterized in that, The fixed flow channel (4) includes a vertical hole A (41) at the top of the nozzle (3) and an oblique hole (42) at the bottom of the fixed flow channel (4). The central axis of the oblique hole (42) intersects the central axis of the guide tube (2). The oblique hole (42) and the vertical hole A (41) are connected through an arc-shaped hole (43).

5. The melt atomization coating equipment according to claim 4, characterized in that, The pre-air chamber (5) includes an annular cavity (51) opened in the integrated ring seat (1). The bottom end of the annular cavity (51) is provided with a plurality of vertical holes B (52) opened relative to the vertical hole A (41). The plurality of vertical holes B (52) are respectively connected to a plurality of movable cavities (16) located above. The integrated ring seat (1) is provided with an input hole (53) communicating with the annular cavity (51). The axis of the input hole (53) is tangent to the inner wall of the annular cavity (51). Among them, the top of the vertical hole A (41), both ends of the through hole (61) and the bottom of the vertical hole B (52) are all provided with threaded grooves.

6. The melt atomization coating equipment according to claim 5, characterized in that, The connecting block (6) has a connecting shaft (64) fixed at one end away from the guide pipe (2), and the connecting shaft (64) is inserted into the rotating annular groove A (12) and fixed with a movable ball block A (65) at the other end away from the connecting block (6). The stop block (63) has a trapezoidal structure near the end of the through hole (61). A connecting rod (66) is fixedly provided at the end of the stop block (63) away from the through hole (61). The end of the connecting rod (66) away from the through hole (61) passes into the circumferential sliding groove (18) and is fixedly provided with a movable ball block B (67).

7. The melt atomization coating equipment according to claim 6, characterized in that, The folded tube unit (7) includes a folded metal tube (71), the folded metal tube (71) has a corrugated cross section, and several folded metal tubes (71) are respectively disposed in several movable cavities (16). Both ends of the folded metal tube (71) are fixedly provided with connecting rings (72), and the end of the connecting ring (72) away from the folded metal tube (71) is rotatably connected with a threaded ring (73). Several threaded rings (73) are respectively threadedly connected to several threaded grooves. Among them, the interference flow ball block (70) is uniformly fixed on the jet flow channel formed by the inner surfaces of the folded metal tube (71), the two connecting rings (72) and the two threaded rings (73).

8. The melt atomization coating equipment according to claim 7, characterized in that, The drive mechanism (8) includes a ring block (81), a gear ring (84), a gear (86), and a motor (87). The ring block (81) is rotatably disposed within the rotating annular groove A (12). A sealed reciprocating guide groove (82) is provided within the ring block (81). An annular through groove (83) communicating with the sealed reciprocating guide groove (82) is provided on the inner surface of the ring block (81). Several connecting shafts (64) are movably connected to the annular through groove (83), and several movable ball blocks A (65) are movably connected to the sealed reciprocating guide groove (82). The gear ring (84) is disposed in the rotating ring groove B (13). The bottom end of the gear ring (84) is rotatably connected to the rotating ring groove B (13) through the rotating ring A (85). The bottom end of the rotating ring A (85) passes through the rotating ring groove A (12) and is fixedly connected to the top end of the ring block (81). The gear (86) is rotatably disposed in the circular groove (14). The motor (87) is fixedly disposed in the mounting cavity (15). The top end of the central shaft of the gear (86) passes through the mounting cavity (15) and is fixedly connected to the output shaft of the motor (87). The sealed reciprocating guide groove (82) is composed of several V-shaped grooves arranged in a ring with equal spacing, with their ends connected.

9. The melt atomization coating equipment according to claim 8, characterized in that, The adjustment mechanism (9) includes a worm gear (91), a worm (94), a number of sector blocks (95) and a number of circumferential sliding plates (98). The worm gear (91) is disposed on the rotating annular groove C (19). The bottom end of the worm gear (91) is rotatably connected to the bottom end of the rotating annular groove C (19) through a rotating ring B (92). A threaded guide groove (93) is provided inside the worm gear (91). The worm (94) is rotatably disposed in the cavity (110). The end of the worm (94) near the groove (111) passes through the groove (111) and is fixedly provided with an adjusting screw block (90). Several sector blocks (95) are slidably disposed in several vertical sliding cavities (17). Several parts are fixedly disposed on the outer surface of the sector blocks (95) in a linear and equally spaced structure. Threaded strips (96), several of the aforementioned threaded strips (96) are evenly fitted to the threaded guide grooves (93). The top two sides of the fan-shaped block (95) are both inclined structures. Inclined guide grooves (97) are provided on the inclined surfaces on both sides of the top of the fan-shaped block (95). Several circumferential sliding plates (98) are slidably disposed in several circumferential sliding grooves (18). Several circumferential sliding plates (98) are respectively connected to several movable ball blocks B (67). An inclined slider (99) is fixedly provided at one end of the circumferential sliding plate (98) near the inclined guide groove (97). The inclined slider (99) is slidably connected to the inclined guide groove (97).

10. The melt atomization coating equipment according to claim 9, characterized in that, The circumferential sliding plate (98) has a transverse groove (981) that is movably connected to the connecting rod (66) at one end near the movable ball block B (67), and a wave groove (982) is provided at the other end of the transverse groove (981) away from the movable ball block B (67). The movable ball block B (67) is movably connected to the wave groove (982).

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