An ultrasonic assisted direct energy deposition additive manufacturing nozzle device

Abstract

The application discloses an ultrasonic-assisted direct energy deposition additive manufacturing nozzle device and belongs to the field of direct energy deposition additive manufacturing. The ultrasonic-assisted direct energy deposition additive manufacturing nozzle device is provided with an ultrasonic wave emitting structure on the periphery of a powder jet head. The ultrasonic wave emitting structure comprises a transverse support, a cover, an ultrasonic wave emitter connecting frame and a sliding block structure. The ultrasonic wave emitter connecting frame is used for loading ultrasonic wave emitters, and all the ultrasonic wave emitters of each layer jointly form the ultrasonic wave emitting structure. By arranging the ultrasonic wave emitting structure in a circumferential array around the laser beam jet head, the powder flow is subjected to the action of ultrasonic wave sound pressure when being sprayed from the nozzle, and is further more concentrated, and more powder particles are contacted with the laser beam, and more powder particles fall into the molten pool, so that the utilization rate of metal powder in the coaxial powder feeding direct energy deposition additive manufacturing is improved.

Description

Technical Field

[0001] This invention belongs to the field of direct energy deposition additive manufacturing, and particularly relates to an ultrasonic-assisted direct energy deposition additive manufacturing nozzle device. Background Technology

[0002] Additive manufacturing technology differs fundamentally from traditional manufacturing techniques. It revolutionizes conventional subtractive machining methods such as forging, casting, turning, and milling, significantly shortening the manufacturing cycle of parts. Metal additive manufacturing is a hot research area today, and its products are increasingly used in aerospace, defense, automotive, and biomedical industries for processing high-precision, complex, and small-batch parts. Commonly used techniques in metal additive manufacturing include powder bed fusion (PBF) technology, which uses a laser beam as a heat source, and direct energy deposition (DAD). The principle of PPF is as follows: metal powder is placed flat on a bed, and a laser beam of less than 1 kW is selectively moved and irradiated according to a pre-programmed path. By locally melting and solidifying the metal powder, a two-dimensional metal layer is created. The bed height is then lowered, and metal powder is applied again to the solidified two-dimensional metal layer, followed by another melting and solidification process to create a three-dimensional shape. The principle of direct energy deposition (DAD) technology is as follows: a high-output laser beam with a power greater than 1 kW is injected, and metal powder is simultaneously sprayed around the laser beam to melt and solidify the metal powder, thereby creating a two-dimensional metal layer. Then, the previously melted and solidified metal layer is irradiated with laser and metal powder is sprayed again to form a new metal layer. By repeating the above process, layers are stacked to create a three-dimensional shape.

[0003] In additive manufacturing of metal structures, companies mostly utilize direct energy deposition (DED) technology. It can not only simultaneously melt and feed powdered materials to create layer-by-layer parts, but also repair damaged parts. Compared to powder bed fusion, DED offers a wider forming range, higher productivity, and is easier to integrate with traditional manufacturing processes such as milling, making it easier to manufacture large components that meet industrial application requirements. Currently, the process methods for spraying metal powder in DED are mainly divided into coaxial powder feeding and off-axis powder feeding. Off-axis powder feeding involves installing a powder feeding nozzle on one side of the laser beam. However, off-axis powder feeding is directional and can only be used for deposition along simple trajectories. It is not suitable for complex deposition paths such as circles and squares, and cannot guarantee the forming dimensions and performance of the additive layer in all directions. Therefore, this method has significant limitations and its application range is not very wide. Coaxial powder feeding enables the powder flow and laser beam to be output coaxially, symmetrical in all directions around the circumference, without directional limitations, and the powder flow has good isotropic characteristics. It can realize both two-dimensional planar additive manufacturing and three-dimensional forming manufacturing, so coaxial powder feeding is widely used.

[0004] Figure 1 This describes the structure of an existing coaxial powder feed nozzle. A laser beam 104 is emitted from a laser beam channel 103, and a powder stream 102 is emitted from a powder stream channel 101. There is a certain angle between the powder stream channel 101 and the laser beam channel 103. The laser beam and the powder stream meet at the lower end of the nozzle to form a molten pool 105. After the powder stream 102 is emitted from the powder stream channel 101, its convergence is low, and much of the powder in the powder stream 102 fails to meet the laser beam 104 to form a molten pool, thus wasting powder and reducing powder utilization. The powders required for direct energy deposition additive manufacturing are very expensive. For example, the cost of feeding spherical Ti6Al-4V additive manufacturing powder particles is between $155 and $330 per kilogram. Therefore, powder waste increases manufacturing costs and hinders the further development of direct energy deposition additive manufacturing. Therefore, if the contact between powder and laser can be improved during the coaxial powder feeding process of direct energy deposition, and a nozzle that can improve powder utilization can be designed, the cost of direct energy deposition additive manufacturing can be reduced to a certain extent, the quality of additively manufactured workpieces can be improved, and the rapid development of laser additive manufacturing research and application fields can be greatly promoted.

[0005] Ultrasonic technology is an effective method to improve powder aggregation. Ultrasound is a high-frequency sound wave with a frequency above 20kHz. The acoustic radiation pressure within an ultrasonic field is stronger than that of a normal sound field. Utilizing this acoustic radiation pressure, objects can overcome their own gravity to achieve a levitation effect (ultrasonic levitation). The acoustic radiation pressure within an ultrasonic field is highly stable, and its magnitude can be controlled by the placement of the ultrasonic transducer and the input voltage. Therefore, the acoustic radiation pressure of ultrasound can be used to improve powder aggregation during coaxial powder feeding in direct energy deposition.

[0006] The significance of this invention lies in providing an ultrasonic-assisted direct energy deposition additive manufacturing nozzle device. This device utilizes ultrasound to improve powder aggregation, effectively increasing powder utilization while ensuring additive manufacturing quality. The invention is simple in principle, easy to implement technically, and fills a gap in direct energy deposition coaxial powder feeding technology for improving powder aggregation. Summary of the Invention

[0007] This invention can improve the aggregation degree of coaxial powder feeding in direct energy deposition, improve powder utilization, and reduce the production cost of direct energy deposition additive manufacturing to a certain extent, thus proposing an ultrasonic-assisted direct energy deposition additive manufacturing nozzle device.

[0008] The technical solution of the present invention to achieve the above functions is as follows:

[0009] An ultrasonic-assisted direct energy deposition additive manufacturing nozzle device is provided, wherein an ultrasonic emission structure is arranged around a powder nozzle 6.

[0010] Preferably, the ultrasonic-assisted direct energy deposition additive manufacturing nozzle device includes an ultrasonic-assisted structure 3, a positioning frame 4, a laser beam nozzle A5, a powder nozzle 6, and a laser beam nozzle B7.

[0011] The uppermost part of the laser beam nozzle A5 is a frustum 501, and the lower end of the frustum 501 is a connecting post 502. The connecting post 502 is divided into two sections. The upper section 502-1 is connected to the frustum 501. The cross-section of the upper section 502-1 is square, and its cross-sectional area is smaller than that of the frustum 501. The cross-section of the lower section 502-2 is circular, and its cross-sectional area is smaller than that of the upper section 502-1. There is a through laser beam channel A503 inside the center of the connecting post 502. The port of the laser beam channel A503 near the frustum 501 is larger. The lower section 502-2 of the connecting post of the laser beam nozzle A5 has external threads 505, and the four sides of the upper section 502-1 have through grooves 504 on their outer walls.

[0012] The top of the laser beam nozzle A5 is detachably connected to the connector 2; the connector 2 is divided into an upper frustum 203 and a lower frustum 202. The diameter of the upper frustum 203 of the connector 2 is smaller than the diameter of the lower frustum 202. The upper frustum 203 is detachably connected to the laser emitting device of the additive manufacturing equipment, and the lower frustum 202 is detachably connected to the frustum 501 of the laser beam nozzle A5; there is a through laser beam channel B201 inside the center of the connector 2. The diameter of the laser beam channel B201 is the same as the diameter of the port of the laser beam channel A503 near the frustum 501.

[0013] The laser beam nozzle B7 is cylindrical in shape, with a through-hole 701 at its center. The diameter of the through-hole 701 is the same as the diameter of the lower section 502-2 of the connecting post of the laser beam channel A503. The through-hole 701 has an internal thread 702, which engages with the external thread 505, thus forming a detachable connection between the laser beam nozzle B7 and the laser beam nozzle A5. After the laser beam nozzle B7 and the laser beam nozzle A5 are connected, the end face of the upper section 502-1 of the connecting post contacts the upper surface 703 of the laser beam nozzle B7.

[0014] The laser beam nozzle B7 has protrusions 704 on its outer wall along the axis. The protrusions 704 are arranged in a circular array and the included angle of the circular array is consistent. Each protrusion 704 has a through channel 705 at its center. The function of the channel 705 is to place the powder nozzle 6.

[0015] The laser beam nozzle B7 has an annular groove 706 around its connection hole 701. The axis of the annular groove 706 coincides with the axis of the laser beam nozzle B7. The water cooling ring 707 is placed in the annular groove 706 in a spiral shape. The inlet / outlet 707-1 of the water cooling ring 707 extends out from the annular groove 706 and is placed in the groove 504 near the upper surface 703.

[0016] The ultrasonic auxiliary structure 3 includes a transverse support 301, a cover 303, an ultrasonic transmitter connecting frame 304, and a slider structure 305. The slider structure 305 is hollow inside, with a square internal cross-section, and the cross-sectional area is the same as that of the upper section 502-1 of the connecting column. The inner wall of the slider structure 305 has protrusions A302, which can cooperate with the grooves 504 during assembly to play a role in positioning and connection. One end of the transverse support 301 is connected to the end of the slider structure 305 and is distributed in an equidistant circular array along the center line of the slider structure 305. The other end of the transverse support 301 is connected to the upper end of the inner wall of the cover 303.

[0017] The cover 303 is in the shape of an inverted cone. The transverse support 301 is connected to the end of the cover 303 with the larger cross-sectional area. At the end of the cover 303 with the smaller cross-sectional area, ultrasonic transmitter connecting frames 304 are distributed in an equidistant circular array. Each ultrasonic transmitter connecting frame 304 has an ultrasonic transmitter fixed on it. All the ultrasonic transmitters in each layer together constitute the ultrasonic transmitting structure 8.

[0018] The internal cross-section of the positioning frame 4 is square, and the cross-sectional area is the same as that of the upper section 502-1 of the connecting column. The four inner walls of the positioning frame have uniformly raised B401, which can cooperate with the groove 504 during assembly to play a role in positioning and connection. During assembly, the positioning frame 4 is located between the laser beam nozzle B7 and the slider structure 305. The lower ends of the two side arms of the positioning frame 4 have gaps 402, which are used to reserve space for the inlet / outlet 707-1 of the water cooling ring during assembly.

[0019] All ultrasonic transmitters in the ultrasonic transmitting structure are connected in parallel; all ultrasonic transmitters in each ultrasonic transmitting structure share a power supply, and the four power supplies are independent of each other. The high-frequency AC signal emitted can be adjusted according to the actual situation; the parallel relationship can ensure that the parameters of the high-frequency AC signal from the power supply obtained by all ultrasonic transmitters in each ultrasonic transmitting structure are consistent, thereby making the sound pressure, sound intensity and force on the powder of the ultrasonic waves emitted by the ultrasonic transmitter consistent.

[0020] The angle of the inverted conical structure of the cover 303 is consistent with the angle between the axis of the channel 705 and the axis of the laser beam nozzle B7; the intersection point between the axis of the channel 705 and the axis of the laser beam nozzle B7 is called the focal point 9.

[0021] Preferably, the draft angle of the laser beam channel A503 is 1.5° to 3.0°; the protrusion 704 has 3 to 4 protrusions; the angle between the axis of the channel 705 and the axis of the laser beam nozzle B7 is 30° to 45°; the depth of the annular groove 706 is 1 / 2 to 2 / 3 of the height of the laser beam nozzle B7; the lower truncated cone 202 has the same diameter as the truncated cone 501 of the laser beam nozzle A5, and when connected, the upper surface of the truncated cone 501 and the lower surface of the lower truncated cone 202 are in coaxial contact.

[0022] Preferably, the powder nozzle 6 includes a nozzle A601, a nozzle B602, and a connector 603; nozzle A601 is conical, nozzle B602 is cylindrical, the outer diameter of nozzle A601 is the same as the outer diameter of nozzle B602, and the function of nozzle B602 is to control the powder flow rate; the inner wall of nozzle A601 has a thread A605, and the lower end of nozzle B602 has a thread B606, and nozzle A601 and nozzle B602 are detachably connected by threads A605 and B606;

[0023] The lower end of nozzle B602 has a baffle 613 and a powder disperser 607. The baffle 613 has a small hole in the center. The powder disperser 607 is fixedly connected to the inner wall of nozzle B602 by a fixing bracket 608. The outlet of the powder disperser 607 needs to be aligned upward with the small hole in the center of the baffle 613. The function of the powder disperser 607 is to make the powder flow more uniform when it flows out of nozzle 601, and to make the outflow profile of the powder flow closer to the Gaussian distribution shape. The upper end of nozzle B602 is connected to connector 603, which is used to connect to external delivery pipes or powder delivery equipment.

[0024] Preferably, an optional method for enabling nozzle B602 to control powder flow rate is as follows: Inside nozzle B602 near the connector 603, there is a ball valve 611 and a ball valve retainer 612. The distance between the ball valve 611 and the ball valve retainer 612 and the final disperser 607 is 8 to 10 times the diameter of the ball valve 611. A ball joint connection is formed between the ball valve retainer 612 and the ball valve 611. The side of the ball valve 611 is fixedly connected to the adjusting rod 604. The ball valve 611 has a through-channel running vertically through it. The upper half of the channel is a small opening 610, and the lower half is a large opening 609. The large opening 609 has the same diameter as the inner wall of the nozzle B602, and the small opening 610 has the same diameter as the inner wall of the connector 603. By rotating the ball valve 611 with the adjusting rod 604, the angle between the small opening 610 and the inner wall of the connector 603 and the angle between the large opening 609 and the inner wall of the flow regulator 602 are adjusted, thereby adjusting the flow rate of the powder outflow regulator 602.

[0025] Preferably, a threaded hole 709 is provided radially on the outer wall of the channel 705; when the powder nozzle 6 is placed in the channel 705, the powder nozzle 6 and the laser beam nozzle B7 are detachably connected by the fixing screw 708 and the threaded hole 709.

[0026] Preferably, the nozzle A601 has an internal diameter of 5mm at the small port and 25mm at the large port; the number of transverse supports 301 is 4.

[0027] Preferably, the ultrasonic transmitter connection frame 304 is distributed in 1 to 5 layers, wherein each layer has at least three ultrasonic transmitter connection frames 304. The number of ultrasonic transmitter connection frames 304 in each layer is the same. The ultrasonic transmitter includes an ultrasonic probe 807, an amplitude transformer 806, and a transducer 805.

[0028] Preferably, after the structure is assembled, the focal point 9 is located 8 to 10 mm below the end 306 of the cover.

[0029] Preferably, all ultrasonic transmitters are assembled in parallel. After assembly, the angle between the centerline 1008 of the ultrasonic transmitter and the centerline 1007 of the powder nozzle is 45-60°. This angle is complementary to the angle between the axis of the channel 705 and the axis of the laser beam nozzle B7. Corresponding ultrasonic transmitters of different layers are located on the same generatrix of the inverted conical structure of the cover 303. The straight-line distance L between the inner end 1009 of the ultrasonic transmitter of different layers located on the same generatrix of the inverted conical structure of the cover 303 and the centerline 1007 of the powder nozzle 6 is equal.

[0030] Compared with existing technologies, the advantages of this invention are as follows: An ultrasonic-assisted direct energy deposition additive manufacturing nozzle device, by arranging ultrasonic emission structures A801, B802, C803, and D804 in a circumferential array around the powder feeding nozzle, makes the powder flow more concentrated under the action of ultrasonic sound pressure when it is ejected from the nozzle 601, thereby increasing the contact between more powder particles and the laser beam, and increasing the amount of powder particles falling into the molten pool, thus improving the utilization rate of powder in direct energy deposition additive manufacturing, and playing a role in saving costs and reducing energy consumption and emissions.

[0031] This invention offers high flexibility, a simple structure, and easy operation, adapting to various working conditions and technical requirements. In this invention, the powder flow rate can be adjusted according to different working conditions. One possible solution is to adjust the flow rate by regulating the angle between the small orifice 610 and the large orifice 609 of the ball valve 611 and the inner wall of the connector 603. In this invention, multiple structural components utilize detachable connections, facilitating component maintenance. For example, the laser beam nozzle A5 and laser beam nozzle B7 are detachably connected via threads; nozzle B602 and nozzle A601 are detachably connected via threads B606 and A605; and the powder nozzle 6 is placed within the channel 705, also with a detachable connection. Attached Figure Description

[0032] The invention will now be further described with reference to the accompanying drawings, in which:

[0033] Figure 1 A schematic diagram of an existing coaxial powder feeding nozzle structure;

[0034] Figure 2 This is a perspective view of the present invention;

[0035] Figure 3 This is a schematic diagram of the structure of the present invention;

[0036] Figure 4 This is a schematic diagram of the structure of the connector 2, laser beam nozzle A5, and laser beam nozzle B6 after assembly according to the present invention;

[0037] Figure 5 for Figure 4 A sectional view;

[0038] Figure 6 This is a schematic diagram illustrating an optional method for detachably assembling the powder nozzle 6 and the channel 705 according to the present invention;

[0039] Figure 7 This is a schematic diagram of the structure of the powder nozzle 6 of the present invention;

[0040] Figure 8 This is a schematic diagram of the ultrasonic-assisted structure 3;

[0041] Figure 9 This is a schematic diagram of the assembled structure of the laser beam nozzle A5, laser beam nozzle B6, ultrasonic auxiliary structure 3, and positioning frame 4 of the present invention.

[0042] Figure 10 This is a schematic diagram of the positioning frame 4 of the present invention;

[0043] Figure 11 This is a schematic diagram of the ultrasonic transmitter of the present invention;

[0044] Figure 12 for Figure 9 A sectional view;

[0045] Figure 13 This is a schematic diagram of the assembled ultrasonic transmitting structure 8 and ultrasonic auxiliary structure 3 of the present invention.

[0046] Figure 14 This is a schematic diagram of the present invention in the direct energy deposition additive manufacturing process;

[0047] In the diagram: 1. Existing coaxial powder feeding nozzle, 101. Powder flow channel, 102. Powder flow, 103. Laser beam channel, 104. Laser beam, 105. Molten pool. 2. Connector, 201. Laser beam channel B, lower frustum 202, upper frustum 203. 3. Ultrasonic auxiliary structure, 301. Lateral support, 302. Protrusion A, 303. Cover, 304. Ultrasonic transmitter connecting frame, 305. Sliding block structure, 306. Cover end. 4. Positioning frame, 401. Protrusion B, 402. Gap. 5. Laser beam nozzle A, 501. Frustum, 502. Connecting post, 502-1. Upper section of connecting post, 502-2. Lower section of connecting post, 503. Laser beam channel A, 504. Groove, 505. External thread. 6. Powder nozzle, 601 Nozzle A, 602 Nozzle B, 603 Connector, 604 Adjusting rod, 605 Thread A, 606 Thread B, 607 Powder disperser, 608 Fixing bracket, 609 Large opening, 610 Small opening, 611 Ball valve, 612 Ball valve holder, 613 Baffle. 7. Laser beam nozzle B, 701 Connecting hole, 702 Internal thread, 703 Upper surface, 704 Protrusion, 705 Channel, 706 Annular groove, 707 Water cooling ring, 707-1 Inlet / outlet, 708 Fixing screw, 709 Threaded hole. 8. Ultrasonic transmitting structure, 801 Ultrasonic transmitting structure A, 802 Ultrasonic transmitting structure B, 803 Ultrasonic transmitting structure C, 804 Ultrasonic transmitting structure D, 805 Transducer, 806 Amplitude rod, 807 Ultrasonic probe. 9. Focal point. 1001 Powder flow, 1002 Laser beam, 1003 New forming layer, 1004 Molten pool, 1005 Forming layer, 1006 Deposited surface, 1007 Powder nozzle centerline, 1008 Ultrasonic transmitter centerline, 1009 Inner end of ultrasonic transmitter. Detailed Implementation

[0048] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be described clearly and completely below with reference to the accompanying drawings.

[0049] like Figures 1 to 14As shown, an ultrasonic-assisted direct energy deposition additive manufacturing nozzle device mainly includes an ultrasonic-assisted structure 3, a positioning frame 4, a laser beam nozzle A5, a powder nozzle 6, a laser beam nozzle B7, and an ultrasonic emission structure 8. The ultrasonic auxiliary structure 3 includes a 301 transverse support, a 302 protrusion A, a 303 cover, a 304 ultrasonic transmitter connecting frame, a 305 slider structure, and a 306 cover end. The laser beam nozzle A5 includes a 501 frustum, a 502 connecting column, a 502-1 upper section of the connecting column, a 502-2 lower section of the connecting column, a 503 laser beam channel A, a 504 groove, and a 505 external thread. The laser beam nozzle B7 includes a 701 connecting hole, a 702 internal thread, a 703 upper surface, a 704 protrusion, a 705 channel, a 706 annular groove, a 707 water-cooling ring, and a 707-1 inlet / outlet. The powder nozzle 6 includes a 601 nozzle A, a 602 nozzle B, a 603 connecting head, a 605 thread A, a 606 thread B, a 607 powder disperser, a 608 fixing frame, and a 613 baffle. The eight ultrasonic transmitting structures are divided into ultrasonic transmitting structure A (801), ultrasonic transmitting structure B (802), ultrasonic transmitting structure C (803), and ultrasonic transmitting structure D (804).

[0050] The uppermost part of the laser beam nozzle A5 is a frustum 501, and the lower end of the frustum 501 is a connecting post 502. The connecting post 502 is divided into two sections: the upper section 502-1, connected to the frustum 501, has a square cross-section with a smaller cross-sectional area than the frustum 501; the lower section 502-2 has a circular cross-section with a smaller cross-sectional area than the upper section 502-1. A through laser beam channel A503 is located inside the center of the connecting post 502. The draft angle of the laser beam channel A503 is 2°, and the port of the laser beam channel A503 closest to the frustum 501 is larger. The lower section 502-2 of the connecting post of the laser beam nozzle A5 has external threads 505, and the four sides of the upper section 502-1 have through grooves 504 on their outer walls.

[0051] The top of the laser beam nozzle A5 is detachably connected to connector 2. Connector 2 consists of an upper frustum 203 and a lower frustum 202. The diameter of the upper frustum 203 is smaller than the diameter of the lower frustum 202. The upper frustum 203 is detachably connected to the laser emitting device of the additive manufacturing equipment, and the lower frustum 202 is detachably connected to the frustum 501 of the laser beam nozzle A5. A through-hole laser beam channel B201 is located inside the center of connector 2. The diameter of the laser beam channel B201 is the same as the diameter of the port of the laser beam channel A503 near the frustum 501. The lower frustum 202 has the same diameter as the frustum 501 of the laser beam nozzle A5. During connection, the upper surface of the frustum 501 and the lower surface of the lower frustum 202 are in coaxial contact.

[0052] The laser beam nozzle B7 is cylindrical in shape, with a through-hole 701 at its center. The diameter of the through-hole 701 is the same as the diameter of the lower section 502-2 of the connecting post of the laser beam channel A503. The through-hole 701 has an internal thread 702, which mates with the external thread 505, thus forming a detachable connection between the laser beam nozzle B7 and the laser beam nozzle A5. After the laser beam nozzle B7 and the laser beam nozzle A5 are connected, the end face of the upper section 502-1 of the connecting post contacts the upper surface 703 of the laser beam nozzle B7.

[0053] The laser beam nozzle B7 has four protrusions 704 on its outer wall along its axis. These protrusions 704 are arranged in a circumferential array with an angular interval of 90°. Each protrusion 704 has a through channel 705 at its center. The angle between the axis of the channel 705 and the axis of the laser beam nozzle B7 is 30°. The channel 705 is used to house the powder nozzle 6.

[0054] The laser beam nozzle B7 has an annular groove 706 around its connection hole 701. The axis of the annular groove 706 coincides with the axis of the laser beam nozzle B7, and the depth of the annular groove 706 is half the height of the laser beam nozzle B7. A water-cooling ring 707 is spirally placed in the annular groove 706. The inlet / outlet 707-1 of the water-cooling ring 707 extends from the annular groove 706 and is placed in a groove 504 near the upper surface 703.

[0055] The powder nozzle 6 includes nozzle A601, nozzle B602, and connector 603. Nozzle A601 is conical, and nozzle B602 is cylindrical. The outer diameters of nozzle A601 and B602 are identical. Nozzle B602 controls the powder flow rate. Nozzle A601 has a thread A605 on its inner wall, and nozzle B602 has a thread B606 at its lower end. Nozzle A601 and nozzle B602 are detachably connected via threads A605 and B606. The inner diameter of the small port of nozzle A601 is 5mm, and the inner diameter of the large port is 25mm.

[0056] The lower end of nozzle B602 has a baffle 613 and a powder disperser 607. The baffle 613 has a small hole in the center. The powder disperser 607 is fixedly connected to the inner wall of nozzle B602 via a mounting bracket 608. The outlet of the powder disperser 607 needs to be aligned upwards with the small hole in the center of the baffle 613. The function of the powder disperser 607 is to make the powder flow more uniform when exiting nozzle 601, making the outflow profile of the powder flow closer to a Gaussian distribution shape. The upper end of nozzle B602 is connected to a connector 603, which is used to connect to an external delivery pipe or powder delivery equipment.

[0057] One possible method to enable nozzle B602 to control powder flow rate is to have a ball valve 611 and a ball valve retainer 612 inside the nozzle B602 near the connector 603. The distance between the ball valve 611 and the ball valve retainer 612 and the final disperser 607 is 10 times the diameter of the ball valve 611. A ball joint connection is formed between the ball valve retainer 612 and the ball valve 611. The side of the ball valve 611 is fixedly connected to the adjusting rod 604. The ball valve 611 has a through-channel running vertically through it. The upper half of the channel is a small opening 610, and the lower half is a large opening 609. The large opening 609 has the same diameter as the inner wall of nozzle B602, and the small opening 610 has the same diameter as the inner wall of connector 603. By rotating the ball valve 611 with the adjusting rod 604, the angle between the small port 610 and the inner wall of the connector 603 and the angle between the large port 609 and the inner wall of the flow regulator 602 are adjusted, thereby adjusting the flow rate of the powder outflow flow regulator 602.

[0058] The powder nozzle 6 is placed in channel 705 and is removable.

[0059] A threaded hole 709 is provided radially on the outer wall of channel 705. After the powder nozzle 6 is placed in channel 705, the powder nozzle 6 is detachably connected to the laser beam nozzle B7 by means of fixing screw 708 and threaded hole 709.

[0060] The ultrasonic auxiliary structure 3 includes a transverse support 301, a cover 303, an ultrasonic transmitter connecting frame 304, and a slider structure 305. The slider structure 305 is hollow inside, with a square internal cross-section, and its cross-sectional area is the same as that of the upper section 502-1 of the connecting column. The inner wall of the slider structure 305 has protrusions A302, which mate with the grooves 504 during assembly, serving a positioning and connecting function. One end of the transverse support 301 is connected to the end of the slider structure 305, and they are distributed in an equidistant circular array along the centerline of the slider structure 305. The other end of the transverse support 301 is connected to the upper end of the inner wall of the cover 303. There are four transverse supports 301.

[0061] The cover 303 is in the shape of an inverted cone. A transverse support 301 is connected to the end of the cover 303 with the larger cross-sectional area. At the end of the cover 303 with the smaller cross-sectional area, four layers of ultrasonic transmitter connection frames 304 are arranged in a circumferentially at equal intervals, with 30 ultrasonic transmitter connection frames 304 in each layer. Each ultrasonic transmitter connection frame 304 has one ultrasonic transmitter fixed to it. All the ultrasonic transmitters in each layer together constitute the ultrasonic transmitting structure 8, specifically ultrasonic transmitting structure A801, ultrasonic transmitting structure B802, ultrasonic transmitting structure C803, and ultrasonic transmitting structure D804.

[0062] The ultrasonic transmitter includes an ultrasonic probe 807, an amplitude transformer 806, and a transducer 805.

[0063] The positioning frame 4 has a square internal cross-section, and its cross-sectional area is the same as that of the upper section 502-1 of the connecting column. The four inner walls of the positioning frame have uniformly protruding B401, which, during assembly, can cooperate with the groove 504 to provide positioning and connection. During assembly, the positioning frame 4 is located between the laser beam nozzle B7 and the slider structure 305. The lower ends of the two side arms of the positioning frame 4 have gaps 402, which provide space for the inlet / outlet 707-1 of the water-cooling ring during assembly.

[0064] All ultrasonic transmitters in ultrasonic transmitting structures A801, B802, C803, and D804 are connected in parallel. All ultrasonic transmitters in each structure share a single power supply; the four power supplies are independent of each other, and the emitted high-frequency AC signal can be adjusted according to actual conditions. This parallel connection ensures that the parameters of the high-frequency AC signal received by all ultrasonic transmitters in each structure are consistent, thereby maintaining consistent sound pressure, sound intensity, and force on the powder emitted by the ultrasonic transmitters.

[0065] The angle of the inverted conical structure of the cover 303 is consistent with the angle between the axis of the channel 705 and the axis of the laser beam nozzle B7. The intersection point between the axis of the channel 705 and the axis of the laser beam nozzle B7 is called the focal point 9. After the structure is assembled, the focal point 9 is located 10 mm below the end 306 of the cover.

[0066] All ultrasonic transmitters in ultrasonic transmitting structures A801, B802, C803, and D804 are assembled in parallel. After assembly, the angle between the center line 1008 of the ultrasonic transmitter and the center line 1007 of the powder nozzle is 60°. The corresponding ultrasonic transmitters in ultrasonic transmitting structures A801, B802, C803, and D804 are located on the same generatrix of the inverted conical structure of the cover 303, and the straight-line distance L between the inner end 1009 of the ultrasonic transmitter located on the same generatrix of the inverted conical structure of the cover 303 and the center line 1007 of the powder nozzle 6 is equal.

[0067] An ultrasonic-assisted direct energy deposition additive manufacturing nozzle device can be applied in the additive manufacturing process using the following steps, such as... Figure 14 As shown:

[0068] Step 1: Secure the nozzle assembly to the laser emitter of the direct energy deposition additive manufacturing equipment via connector 2.

[0069] Step 2: Adjust the powder flow rate by rotating the ball valve 611 using the adjusting rod 604 to adapt to the actual working conditions. Connect the inlet and outlet water pipes to the inlet / outlet 707-1 of the water-cooling ring to maintain a circulating water supply for continuous cooling of the nozzle device.

[0070] Step 3: Powder is fed to nozzle 6 via connector 603. Power is turned on and an appropriate power is selected, causing ultrasonic transmitting structures A801, B802, C803, and D804 to emit ultrasonic waves, thus creating a sound pressure field around the powder flow. The laser emitter of the additive manufacturing equipment emits a laser beam 1002, which contacts the powder 1001 to form a molten pool 1004. Due to the sound pressure field, the powder flow 1001 is relatively concentrated, ensuring full contact with the laser beam 1002, greatly reducing powder waste.

[0071] Step 4: The laser emitter of the direct energy deposition additive manufacturing equipment moves in a translational motion, which in turn drives the entire nozzle assembly to move in a translational motion via connector 2. Due to the action of the ultrasonic emission structure 8, the powder stream 1001 comes into full contact with the laser beam 1002, and most of the powder falls into the molten pool 1004. A new forming layer 1005 is formed on the deposition surface 1006 of the forming layer 1005. The laser cladding head repeatedly moves in a translational motion on the workpiece surface to achieve direct energy deposition additive manufacturing.

[0072] Compared with existing technologies, the advantages of this invention are as follows: An ultrasonic-assisted direct energy deposition additive manufacturing nozzle device, which fully integrates the advantages of mechanics and mechanical design, improves powder utilization during additive manufacturing, saves raw materials, and reduces production costs. By arranging ultrasonic emission structures 8 in a circumferential array around the powder feeding nozzle, the powder flow is more concentrated under the action of ultrasonic sound pressure when ejected from nozzle A601, resulting in more powder particles contacting the laser beam and more powder particles falling into the molten pool. This improves powder utilization in direct energy deposition additive manufacturing, achieving cost savings, energy conservation, emission reduction, and environmental protection. In this invention, multiple structures employ detachable connections for easy maintenance and upkeep. For example, laser beam nozzle A5 and laser beam nozzle B7 are connected by threads; nozzle B602 and nozzle A601 are detachably connected by threads B606 and A605; the powder nozzle 6 is placed in channel 705 and is detachably connected.

Claims

1. An ultrasonic-assisted direct energy deposition additive manufacturing nozzle device, characterized in that, The ultrasonic-assisted direct energy deposition additive manufacturing nozzle device has an ultrasonic emission structure set around the powder nozzle (6); The ultrasonic-assisted direct energy deposition additive manufacturing nozzle device includes an ultrasonic-assisted structure (3), a positioning frame (4), a laser beam nozzle A (5), a powder nozzle (6), and a laser beam nozzle B (7). The uppermost part of the laser beam nozzle A (5) is a frustum (501), and the lower end of the frustum (501) is a connecting column (502). The connecting column (502) is divided into two sections. The upper section (502-1) of the connecting column is connected to the frustum (501). The cross-section of the upper section (502-1) of the connecting column is square, and the cross-sectional area is smaller than that of the frustum (501). The cross-section of the lower section (502-2) of the connecting column is circular, and the cross-sectional area is smaller than that of the upper section (502-1). There is a through laser beam channel A (503) inside the center of the connecting column (502). The port of the laser beam channel A (503) near the frustum (501) is larger. There is an external thread (505) on the lower section (502-2) of the connecting column of the laser beam nozzle A (5). There are through grooves (504) on the four outer walls of the upper section (502-1). The top of the laser beam nozzle A (5) is detachably connected to the connector (2); the connector (2) is divided into an upper truncated cone (203) and a lower truncated cone (202). The diameter of the upper truncated cone (203) of the connector (2) is smaller than the diameter of the lower truncated cone (202). The upper truncated cone (203) is detachably connected to the laser emitting device of the additive manufacturing equipment, and the lower truncated cone (202) is detachably connected to the truncated cone (501) of the laser beam nozzle A (5); there is a through laser beam channel B (201) inside the center of the connector (2). The diameter of the laser beam channel B (201) is the same as the diameter of the port of the laser beam channel A (503) near the truncated cone (501). The laser beam nozzle B (7) is cylindrical in shape, with a through connection hole (701) in the center. The diameter of the connection hole (701) is the same as the diameter of the lower section (502-2) of the connecting post of the laser beam channel A (503). The connection hole (701) has an internal thread (702), which is matched with the external thread (505) to form a detachable connection between the laser beam nozzle B (7) and the laser beam nozzle A (5). After the laser beam nozzle B (7) and the laser beam nozzle A (5) are connected, the end face of the upper section (502-1) of the connecting post contacts the upper surface (703) of the laser beam nozzle B (7). The laser beam nozzle B (7) has a protrusion (704) on its outer wall along the axis. The protrusions (704) are arranged in a circumferential array and the included angle of the circumferential array is consistent. Each protrusion (704) has a through channel (705) at its center. The function of the channel (705) is to place the powder nozzle (6). The laser beam nozzle B (7) has an annular groove (706) around the connecting hole (701). The axis of the annular groove (706) coincides with the axis of the laser beam nozzle B (7). The water cooling ring (707) is placed in the annular groove (706) in a spiral shape. The inlet / outlet (707-1) of the water cooling ring (707) extends out from the annular groove (706) and is placed in the groove (504) near the upper surface (703). The ultrasonic auxiliary structure (3) includes a transverse support (301), a cover (303), an ultrasonic transmitter connecting frame (304), and a slider structure (305). The slider structure (305) is hollow inside, with a square internal cross-section, and the cross-sectional area is the same as that of the upper section (502-1) of the connecting column. The inner wall of the slider structure (305) has protrusions A (302), which can cooperate with the grooves (504) during assembly to play a role in positioning and connection. One end of the transverse support (301) is connected to the end of the slider structure (305), and is distributed in an equidistant circular array along the center line of the slider structure (305). The other end of the transverse support (301) is connected to the upper end of the inner wall of the cover (303). The cover (303) is in the shape of an inverted cone. The transverse support (301) is connected to the end of the cover (303) with the larger cross-sectional area. At the end of the cover (303) with the smaller cross-sectional area, ultrasonic transmitter connecting frames (304) are distributed in an equidistant circular array. Each ultrasonic transmitter connecting frame (304) has an ultrasonic transmitter fixed on it. All the ultrasonic transmitters in each layer together constitute the ultrasonic transmitting structure (8). The internal cross-section of the positioning frame (4) is square, and the cross-sectional area is the same as that of the upper section (502-1) of the connecting column; the four inner walls of the positioning frame have uniformly raised B (401), which can cooperate with the groove (504) during assembly to play the role of positioning and connection; during assembly, the positioning frame (4) is located between the laser beam nozzle B (7) and the slider structure (305); the two side arms of the positioning frame (4) have gaps (402) at their lower ends, which are used to reserve space for the inlet / outlet (707-1) of the water cooling ring during assembly; All ultrasonic transmitters in the ultrasonic transmitting structure are connected in parallel; all ultrasonic transmitters in each ultrasonic transmitting structure share a power supply, and the four power supplies are independent of each other. The high-frequency AC signal emitted can be adjusted according to the actual situation; the parallel relationship can ensure that the parameters of the high-frequency AC signal from the power supply obtained by all ultrasonic transmitters in each ultrasonic transmitting structure are consistent, thereby making the sound pressure, sound intensity and force on the powder of the ultrasonic waves emitted by the ultrasonic transmitter consistent. The angle of the inverted conical structure of the cover (303) is consistent with the angle between the axis of the channel (705) and the axis of the laser beam nozzle B (7); the intersection point between the axis of the channel (705) and the axis of the laser beam nozzle B (7) is called the focal point (9).

2. The ultrasonic-assisted direct energy deposition additive manufacturing nozzle device according to claim 1, characterized in that, The draft angle of the laser beam channel A (503) is 1.5°~3.0°; there are 3~4 protrusions (704); the angle between the axis of the channel (705) and the axis of the laser beam nozzle B (7) is 30°~45°; the depth of the annular groove (706) is 1 / 2~2 / 3 of the height of the laser beam nozzle B (7); the lower truncated cone (202) has the same diameter as the truncated cone (501) of the laser beam nozzle A (5), and when connected, the upper surface of the truncated cone (501) and the lower surface of the lower truncated cone (202) are in coaxial contact.

3. The ultrasonic-assisted direct energy deposition additive manufacturing nozzle apparatus according to claim 1, characterized in that, The powder nozzle (6) includes nozzle A (601), nozzle B (602), and connector (603); nozzle A (601) is conical, nozzle B (602) is cylindrical, the outer diameter of nozzle A (601) is consistent with the outer diameter of nozzle B (602), and the function of nozzle B (602) is to control the flow rate of powder; the inner wall of nozzle A (601) has thread A (605), and the lower end of nozzle B (602) has thread B (606). Nozzle A (601) and nozzle B (602) can be detachably connected by thread A (605) and thread B (606); The lower end of nozzle B (602) has a baffle (613) and a powder disperser (607). The baffle (613) has a small hole in the center. The powder disperser (607) is fixedly connected to the inner wall of nozzle B (602) by a fixing bracket (608). The outlet of the powder disperser (607) needs to be aligned upward with the small hole in the center of the baffle (613). The function of the powder disperser (607) is to make the powder flow more uniform when it flows out of nozzle (601) and to make the outline of the powder flow closer to the Gaussian distribution shape. The upper end of nozzle B (602) is connected to a connector (603). The connector (603) is used to connect to an external powder feeding pipe or powder feeding equipment.

4. The ultrasonic-assisted direct energy deposition additive manufacturing nozzle device according to claim 3, characterized in that, One method to enable nozzle B (602) to control the powder flow rate is to have a ball valve (611) and a ball valve retainer (612) inside the nozzle B (602) near the connector (603), the distance between the ball valve (611) and the ball valve retainer (612) and the powder disperser (607) being 8 to 10 times the diameter of the ball valve (611); a ball joint connection is formed between the ball valve retainer (612) and the ball valve (611); the side of the ball valve (611) is fixedly connected to the adjusting rod (604). The ball valve (611) has a through-channel running vertically through it. The upper half of the channel is a small opening (610), and the lower half is a large opening (609). The large opening (609) has the same inner diameter as the nozzle B (602), and the small opening (610) has the same inner diameter as the connector (603). By rotating the ball valve (611) with the adjusting rod (604), the angle between the small opening (610) and the inner wall of the connector (603) and the angle between the large opening (609) and the inner wall of the flow regulator are adjusted, thereby adjusting the flow rate of the powder outflow from the flow regulator.

5. The ultrasonic-assisted direct energy deposition additive manufacturing nozzle device according to claim 1, characterized in that, A threaded hole (709) is provided on the radial side of the outer wall of the channel (705); after the powder nozzle (6) is placed in the channel (705), the powder nozzle (6) and the laser beam nozzle B (7) are detachably connected by fixing screws (708) and threaded holes (709).

6. The ultrasonic-assisted direct energy deposition additive manufacturing nozzle apparatus according to claim 1, characterized in that, Nozzle A (601) has an inner diameter of 5 mm at the small port and 25 mm at the large port; there are 4 transverse supports (301).

7. The ultrasonic-assisted direct energy deposition additive manufacturing nozzle apparatus according to claim 1, characterized in that, After the structure is assembled, the focal point (9) is located 8-10 mm below the end of the cover (306).

8. The ultrasonic-assisted direct energy deposition additive manufacturing nozzle apparatus according to claim 1, characterized in that, All ultrasonic transmitters are assembled in parallel. After assembly, the angle between the center line (1008) of the ultrasonic transmitter and the center line (1007) of the powder nozzle is 45~60°. This angle is complementary to the angle between the axis of the channel (705) and the axis of the laser beam nozzle B (7). The corresponding ultrasonic transmitters of different layers are on the same generatrix of the inverted conical structure of the cover (303). The straight distance L between the inner end (1009) of the ultrasonic transmitter of different layers on the same generatrix of the inverted conical structure of the cover (303) and the center line (1007) of the powder nozzle is equal.

9. The ultrasonic-assisted direct energy deposition additive manufacturing nozzle apparatus according to claim 1, characterized in that, The ultrasonic transmitter connecting frame (304) is distributed in 1 to 5 layers, wherein the number of ultrasonic transmitter connecting frames (304) in each layer is greater than or equal to three; the number of ultrasonic transmitter connecting frames (304) in each layer is the same; the ultrasonic transmitter includes an ultrasonic probe (807), an amplitude transformer (806), and a transducer (805).

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