An additive manufacturing apparatus and method using multi-field assisted arc fuse wire

Abstract

This invention belongs to the field of additive manufacturing technology, and provides an additive manufacturing apparatus and method using multi-energy field assisted arc welding wire. The apparatus includes: a worktable, an additive manufacturing unit, an AC / DC magnetic field unit, an ultrasonic vibration unit, and a mechanical impact unit. The additive manufacturing unit includes an arc welding torch fixed to a first robotic arm. The AC / DC magnetic field unit includes an AC / DC magnetic field mechanism, a oscillating mechanism, and a connecting frame. The connecting frame is connected to the first robotic arm, the oscillating mechanism is connected to the connecting frame, and the AC / DC magnetic field mechanism is connected to the oscillating mechanism. The oscillating mechanism is used to move the AC / DC magnetic field mechanism closer to or further away from the welding position of the arc welding torch. The ultrasonic vibration unit is fixed to the worktable and is used to apply ultrasonic vibration to the substrate. The mechanical impact unit is fixed to a second robotic arm and is used to perform accompanying mechanical impact on the deposited layer of the welded portion. This invention enables multi-energy field synergistic control, optimizes microstructure, reduces defects, improves overall performance, and enhances forming quality and additive manufacturing stability.

Description

Technical Field

[0001] This invention belongs to the field of additive manufacturing technology, and provides an additive manufacturing device and method using multi-energy field assisted electric arc fuse. Background Technology

[0002] Additive manufacturing, as an emerging manufacturing technology, employs a layer-by-layer manufacturing method to create desired structural components through a bottom-up and layer-by-layer stacking process. Wire and Arc Additive Manufacturing (WAAM) technology is one type of additive manufacturing technology. It is a metal additive manufacturing technology based on an electric arc heat source, using an electric arc to melt metal wire and deposit it layer by layer to form a three-dimensional solid part. This technology has advantages such as high production efficiency, high material utilization, and low manufacturing cost. Compared with other metal additive manufacturing technologies, WAAM is more suitable for manufacturing and processing large and complex metal parts, and is an advanced manufacturing technology for achieving lightweight design of component structures.

[0003] Due to the inherent characteristics of WAAM technology, during additive manufacturing, the molten pool metal mainly solidifies in a free state due to continuous heat input and severe temperature gradients. This results in uneven microstructure distribution and the presence of coarse columnar crystals. Furthermore, the instability of the dynamic molten pool easily leads to poor forming quality. At the same time, the intense non-equilibrium solidification process causes defects such as porosity, microcracks, and thermal stress accumulation, which in turn reduces the overall performance of metal components, including strength, toughness, and fatigue performance. This makes it difficult to meet the requirements of some high-end applications and restricts the widespread application of WAAM technology.

[0004] Currently, methods to improve the forming quality and control the microstructure and mechanical properties of additively manufactured components include introducing external energy to assist in controlling the molten pool and mechanical processing methods. In terms of mechanical processing, ultrasonic vibration assistance and interlayer ultrasonic impact are effective methods to optimize the forming quality and mechanical properties of additively manufactured components. Adding an external magnetic field during the additive manufacturing process is a non-contact external assistance method. The external magnetic field is highly flexible and can effectively improve the molten pool flow and arc morphology, thus optimizing the forming quality and mechanical properties of the additively manufactured components. Chinese patent CN202010599024.9 discloses a magnetic field composite ultrasonic vibration arc additive manufacturing device and method. This device applies a magnetic field generator to an arc welding torch. During the additive manufacturing process, the arc and molten pool are subjected to a longitudinal magnetic field. The static longitudinal magnetic field has certain limitations in its effect on directionally improving the backward flow of liquid metal in the molten pool during high deposition efficiency. Applying ultrasonic vibration to the bottom of the substrate inhibits grain growth within the molten pool. As the number of deposition layers increases, the effect of ultrasonic vibration on the interior of the deposition layers becomes uneven, making it difficult to guarantee the performance of the components during manufacturing and hindering further improvements in production efficiency. Summary of the Invention

[0005] To address the aforementioned technical problems, this invention provides an additive manufacturing apparatus and method employing multi-energy field assisted arc filament, which enables multi-energy field synergistic control to optimize microstructure, reduce defects, improve overall performance, and enhance forming quality and additive stability.

[0006] The technical solution of the present invention includes: a workbench.

[0007] The additive manufacturing unit includes an arc welding gun fixed to a first robotic arm.

[0008] The AC / DC magnetic field unit includes an AC / DC magnetic field mechanism, a swing mechanism, and a connecting frame. The connecting frame is connected to the first robotic arm, the swing mechanism is connected to the connecting frame, and the AC / DC magnetic field mechanism is connected to the swing mechanism. The swing mechanism is used to move the AC / DC magnetic field mechanism closer to or away from the welding position of the arc welding gun. The DC magnetic field and AC magnetic field generated by the AC / DC magnetic field unit act on the welding arc and molten pool, and regulate the flow of the molten pool and the shape of the arc through the Lorentz force, thereby continuously stirring the molten pool.

[0009] An ultrasonic vibration unit, fixed on a worktable, is used to apply ultrasonic vibrations to a substrate.

[0010] The mechanical impact unit, fixed to the second robotic arm, is used to perform accompanying mechanical impact on the deposited layer of the welded part.

[0011] Furthermore, the swing mechanism includes: The motor is fixed above the connecting frame.

[0012] The swing arm is connected to the output shaft of the motor, and the AC / DC magnetic field mechanism is connected to the swing arm. The motor drives the AC / DC magnetic field mechanism to move closer to or away from the welding position of the arc welding gun through the rotation of the swing arm.

[0013] Furthermore, a gear set is provided between the motor and the swing arm.

[0014] Furthermore, the rotation angle of the swing arm is between 0 degrees and 80 degrees.

[0015] Furthermore, the AC / DC magnetic field mechanism includes: The iron core is connected to the swing rod, and the lower end of the iron core is always at a 45° angle to the molten pool.

[0016] The DC component includes an inner cylinder fitted onto the iron core and an internal excitation coil wound around the outer wall of the inner cylinder, the internal excitation coil being connected to a DC power supply.

[0017] An AC component includes an outer cylinder and an external excitation coil wound around the outer wall of the outer cylinder. The external excitation coil is connected to an AC power source. The inner cylinder is located inside the outer cylinder, and there is a gap between the inner wall of the outer cylinder and the internal excitation coil.

[0018] Furthermore, the winding height of the internal excitation coil and the external excitation coil is between 70mm and 80mm.

[0019] Furthermore, the current provided by both the DC power supply and the AC power supply is between 1A and 5A.

[0020] Furthermore, the ultrasonic vibration unit includes an ultrasonic vibration generator and an ultrasonic vibration mechanism; the ultrasonic vibration mechanism is fixed on the worktable and acts on the substrate, and the ultrasonic vibration generator is used to control the working frequency and amplitude of the ultrasonic vibration mechanism.

[0021] Furthermore, the ultrasonic vibration mechanism operates at a frequency between 20 kHz and 30 kHz, and has an amplitude between 40 μm and 50 μm.

[0022] Furthermore, the mechanical impact unit includes a mechanical impact head and a mechanical impact generator connected to the mechanical impact head; the mechanical impact head is fixed on the second robotic arm, and the mechanical impact generator is used to control the frequency and amplitude of the mechanical impact head.

[0023] The present invention also provides an additive manufacturing method for electric arc fuses, comprising: The substrate surface is sanded with sandpaper and cleaned with alcohol. The substrate and ultrasonic vibration mechanism are fixed on the worktable. The contact position of the ultrasonic vibration mechanism is adjusted so that the ultrasonic vibration mechanism is close to the substrate. Turn on the power to enable the ultrasonic vibration mechanism to apply ultrasonic vibration to the substrate and transmit ultrasonic waves to the substrate; enable the AC / DC magnetic field mechanism to generate DC magnetic field and AC magnetic field, and enable the oscillating mechanism to drive the AC / DC magnetic field mechanism to perform periodic reciprocating oscillation, thereby controlling the flow of the molten pool and the shape of the arc and the molten pool through Lorentz force, and continuously stirring the molten pool. The arc welding gun is turned on to perform additive manufacturing on the substrate. After the additive manufacturing of this layer is completed, the arc welding gun continues to deposit the next layer of additive manufacturing according to the preset additive manufacturing path until the process is completed.

[0024] The technical solution provided by this invention has the following advantages compared with the prior art: The worktable provides a supporting foundation for the substrate and various functional units. The first robotic arm drives the arc welding gun of the additive manufacturing unit to complete the basic additive manufacturing action of wire melting and layer-by-layer deposition. The AC / DC magnetic field unit moves synchronously with the first robotic arm and drives the AC / DC magnetic field unit to move closer to or away from the welding position through the swing mechanism, applying AC / DC magnetic field to the arc and molten pool. The ultrasonic vibration unit is fixed on the worktable to apply ultrasonic vibration to the substrate and transmit it to the molten pool. The second robotic arm drives the mechanical impact unit to perform follow-up mechanical impact on the weld deposition layer, realizing the synergistic effect of multiple energy fields such as AC / DC magnetic field, ultrasonic vibration, and mechanical impact with the additive manufacturing process. The beneficial effects of this device specifically address many technical problems in arc-fused wire additive manufacturing in the background technology: First, by coordinating the flow of the molten pool and the arc morphology through multiple energy fields, it solves the problem of poor forming quality caused by the instability of the dynamic molten pool; second, by using the combined effect of magnetic field and ultrasound to refine grains, it solves the problem of uneven microstructure distribution and the presence of coarse columnar crystals caused by the free solidification of the molten pool metal; third, by promoting the overflow of bubbles in the molten pool through ultrasonic cavitation effect and releasing thermal stress through mechanical impact, it solves the problems of defects such as pores, microcracks, and thermal stress accumulation generated during non-equilibrium solidification; fourth, it breaks through the limitations of traditional single auxiliary energy field control, comprehensively improving the comprehensive performance of metal components such as strength, toughness, and fatigue performance, solving the problem that components prepared by traditional technology cannot meet the requirements of high-end application fields; fifth, compared with the traditional static longitudinal magnetic field + ultrasound auxiliary method, the combination of oscillating AC and DC magnetic field and accompanying mechanical impact solves the problems of limited effect of magnetic field on improving the flow of molten pool metal and uneven effect of ultrasonic vibration on multi-layer deposited parts, improving production efficiency and component performance stability.

[0025] Other advantages, objectives and features of the present invention will become apparent in part from the following description, and in part from those skilled in the art through study and practice of the invention. Attached Figure Description

[0026] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0027] Figure 1 This is a schematic diagram of the overall structure of the multi-field assisted arc fuse additive manufacturing method and apparatus provided in this application; Figure 2 This is a schematic diagram of the AC / DC magnetic field and ultrasonic vibration in the additive manufacturing apparatus provided in this application.

[0028] Figure 3This is a schematic diagram of the AC / DC magnetic field generating component provided in the embodiments of this application, wherein (a) is a schematic diagram of a circular iron core, (b) is a schematic diagram of an internal coil and an inner cylinder, (c) is a schematic diagram of an external coil and an outer cylinder, and (d) is a schematic diagram of the overall structure.

[0029] Figure 4 This is a schematic diagram of the reciprocating oscillation of AC and DC magnetic fields in a magnetic field composite external auxiliary arc fuse device according to this application.

[0030] Figure 5 This is a schematic diagram of the deposited layer after additive manufacturing using CMT arc fuse without any auxiliary materials.

[0031] Figure 6 This is a schematic diagram of CMT arc fuse additive manufacturing using the technical method described in this application.

[0032] Figure 7 This is a schematic diagram of the metallographic structure of the deposited layer after additive manufacturing using CMT arc fuse without any auxiliary materials.

[0033] Figure 8 This is a schematic diagram of the metallographic structure of CMT arc fuse additive manufacturing using the technical method of this application.

[0034] Figure 9 This is a schematic diagram comparing the stress-strain of the tensile performance test of the additive component with the CMT arc fuse without any auxiliary material and the CMT arc fuse of this application.

[0035] Figure 10 This is a high-speed camera comparison diagram of the CMT arc fuse additive manufacturing process without any assistance and the CMT arc fuse additive manufacturing process of this application.

[0036] Figure label: 1. Welding power source; 2. Wire feeder; 3. First robot; 4. Motor power supply; 5. Arc welding torch; 6. AC / DC magnetic field unit; 7. Ultrasonic vibration generator; 8. Second robot; 9. Mechanical impact generator; 10. Ultrasonic vibration mechanism; 11. Mechanical impact head; 12. DC power supply; 13. AC power supply; 14. Worktable; 15. Base plate; 16. Fixture; 17. Gear set; 18. Motor; 19. Bolt; 20. Fixture; 21. Swing rod; 22. Deposition layer; 23. Circular iron core; 24. Inner cylinder; 25. Small screw hole; 26. Machining notch; 27. Internal excitation coil; 28. Outer cylinder; 29. ​​External excitation coil; 30. Small bolt. Detailed Implementation

[0037] The following detailed description of a specific embodiment of the present invention is provided in conjunction with the accompanying drawings. However, it should be understood that the scope of protection of the present invention is not limited to the specific embodiment.

[0038] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the technical solution of this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0039] In the description of the embodiments of the present invention, unless otherwise stated, "a plurality of" means two or more.

[0040] like Figures 1 to 10 As shown, this invention provides a multi-field assisted arc welding wire additive manufacturing device, comprising a worktable 14, a first robot 3, a second robot 8, an additive manufacturing unit, an AC / DC magnetic field unit 6, an ultrasonic vibration unit, and a mechanical impact unit. The first robot 3 is equipped with a first robotic arm, and the second robot 8 is equipped with a second robotic arm. The additive manufacturing unit includes a CMT arc welding torch 5 fixed on the first robotic arm, and is also equipped with a welding power source 1 and a wire feeder 2. The CMT arc welding torch 5 is electrically connected to the welding power source 1 and the wire feeder 2, respectively. The wire feeder 2 continuously feeds metal wire to the CMT arc welding torch 5, and the welding power source 1 provides an arc heat source for the CMT arc welding torch 5. The AC / DC magnetic field unit 6 includes an AC / DC magnetic field mechanism, a swing mechanism, and a connecting frame. The connecting frame is fixedly connected to the first robotic arm, the swing mechanism is connected to the connecting frame, and the AC / DC magnetic field mechanism is connected to the first robotic arm. The oscillating mechanism connects to the AC / DC magnetic field mechanism, which can move the AC / DC magnetic field mechanism closer to or further away from the welding position of the CMT arc welding gun 5. The AC / DC magnetic field unit 6 is used to generate AC / DC magnetic fields and apply them to the arc, molten droplets, and molten pool during the welding process. The ultrasonic vibration unit is fixed on the worktable 14 and is used to apply ultrasonic vibration to the substrate 15 placed on the worktable 14. The ultrasonic vibration can be transmitted along the substrate 15 to the molten pool area. The mechanical impact unit is fixed on the second robotic arm and is used to perform a follow-up mechanical impact on the deposition layer 22 during the welding process, realizing a conformal mechanical impact on the deposition layer 22. The first robot 3 drives the additive manufacturing unit and the AC / DC magnetic field unit 6 to move synchronously through the first robotic arm. The second robot 8 drives the mechanical impact unit to move in real time along the additive path through the second robotic arm, realizing the synergistic effect of the AC / DC magnetic field, ultrasonic vibration, and mechanical impact multi-energy field.

[0041] When the device is working, the workbench 14 provides a fixed support foundation for the substrate 15 and each unit. The first robot 3 precisely controls the movement trajectory and speed of the CMT arc welding gun 5 through the first robotic arm to achieve the melting of the wire and the deposition of layers. The wire feeder 2 works in conjunction with the welding power source 1 to continuously supply the metal wire and arc heat source to the CMT arc welding gun 5 to complete the basic additive manufacturing action. The AC / DC magnetic field unit 6 moves synchronously with the CMT arc welding gun 5, and the oblique longitudinal AC / DC magnetic field generated dynamically acts on the arc, droplets and molten pool to regulate the flow of the molten pool and the shape of the arc. The ultrasonic vibration unit applies ultrasonic vibration from the end of the substrate 15, which is transmitted to the molten pool through the substrate 15 to act on the liquid metal in the molten pool. The second robot 8 drives the mechanical impact unit to move along the additive path and applies mechanical impact in real time during the formation of the deposition layer 22. The multi-energy fields cooperate in time and space to participate in the solidification of the molten pool and the formation of the deposition layer 22 in the entire additive manufacturing process.

[0042] Furthermore, the connecting frame includes a fixed frame 16 and a clamp 20. One end of the clamp 20 is connected to the first robotic arm. The fixed frame 16 is connected to the other end of the clamp 20. The swing mechanism is fixed on the fixed frame 16.

[0043] In the embodiment provided by the present invention, the swing mechanism includes a motor 18 and a swing rod 21. The motor 18 is fixed above the connecting frame and is electrically connected to an external motor power supply 4 to provide power for the movement of the mechanism. The swing rod 21 is fixedly connected to the output shaft of the motor 18. The AC / DC magnetic field mechanism is fixedly connected to the end of the swing rod 21 away from the motor 18. The motor 18 can drive the swing rod 21 to rotate, thereby moving the AC / DC magnetic field mechanism closer to or away from the welding position of the CMT arc welding gun 5. The connecting frame serves as a fixing device for the AC / DC magnetic field unit 6, realizing the clamping and fixing of the AC / DC magnetic field unit 6, and realizing the periodic reciprocating swing of the AC / DC magnetic field unit 6 through the drive of the motor 18.

[0044] After the motor power supply 4 supplies power to the motor 18, the output shaft of the motor 18 drives the swing rod 21 to rotate around the connection point. The rotation of the swing rod 21 directly drives the fixed AC / DC magnetic field mechanism to move synchronously. By controlling the forward and reverse rotation and rotation angle of the motor 18, the AC / DC magnetic field mechanism can move closer to or further away from the welding position, thereby completing the periodic reciprocating oscillation of the AC / DC magnetic field unit 6, so that the AC / DC magnetic field can dynamically act on the arc, molten droplets and molten pool in the welding process, rather than statically fixing.

[0045] In the embodiment provided by the present invention, a gear set 17 is provided between the motor 18 and the swing rod 21. The gear set 17 meshes with the output shaft of the motor 18. The swing rod 21 is fixedly connected to the end of the gear set 17 away from the motor 18. The motor 18 drives the gear set 17 to rotate. The gear set 17 drives the swing rod 21 and the fixed AC / DC magnetic field unit 6 to reciprocate.

[0046] After the motor 18 starts, the output shaft drives the meshing gear set 17 to perform meshing transmission, transmitting the rotational motion of the motor 18 to the swing rod 21 through the gear set 17. The rotational speed and torque of the swing rod 21 are adjusted by the transmission ratio of the gear set 17, so as to achieve precise control of the rotation angle and swing frequency of the swing rod 21, thereby driving the AC / DC magnetic field unit 6 to perform periodic reciprocating swing according to the preset amplitude and frequency.

[0047] The gear set 17 of this invention features a fixed transmission ratio and high transmission accuracy, effectively compensating for the angular error caused by the direct drive of the motor 18, ensuring the accuracy of the swing angle of the AC / DC magnetic field unit 6, and avoiding deviation in the magnetic field's position. The gear set 17 can amplify torque, reducing the power output requirements of the motor 18. A small-power motor 18 can be used to drive the AC / DC magnetic field unit 6 to complete the swing, saving equipment energy and reducing device manufacturing costs. The gear transmission structure is stable, has strong impact resistance, and can adapt to the vibration environment during additive manufacturing, avoiding transmission mechanism failure and ensuring the long-term reliability of the device. The transmission speed of the gear set 17 can be flexibly designed. By adjusting the gear module and number of teeth, the swing frequency of the AC / DC magnetic field unit 6 can be adjusted in multiple gears to meet the needs of different additive manufacturing processes.

[0048] In the embodiments provided by the present invention, the rotation angle of the swing rod 21 is between 0 degrees and 80 degrees, that is, the reciprocating swing angle 2β of the AC / DC magnetic field unit 6 is 0°-80°; the AC / DC magnetic field mechanism and the swing rod 21 are adjustablely connected. By adjusting the connection position of the AC / DC magnetic field mechanism on the swing rod 21, the AC / DC magnetic field mechanism and the substrate 15 are made to form a 45° angle, ensuring that the central axis of the magnetic field generated by the AC / DC magnetic field passes through the central region of the molten pool.

[0049] Through the coordinated control of motor 18 and gear set 17, the rotation angle of swing rod 21 is limited to 0-80°, so that AC / DC magnetic field unit 6 oscillates periodically within this angle range, allowing the oblique longitudinal AC / DC magnetic field to dynamically act on the molten pool from different angles; by adjusting the connection position between AC / DC magnetic field mechanism and swing rod 21, the spatial placement angle of magnetic field mechanism is changed, so that magnetic field mechanism and substrate 15 form a 45° angle, ensuring that magnetic field lines pass through the molten pool at the optimal angle, and maximizing the Lorentz force of magnetic field on liquid metal in molten pool.

[0050] The rotation angle of the swing rod 21 in this invention is limited to 0-80°. Experimental verification shows that this angle range ensures the dynamic effect of the magnetic field on the molten pool, avoiding both excessively small angles leading to a singular magnetic field effect and excessively large angles causing the magnetic field to deviate from the molten pool, thus failing to effectively control the molten pool flow. The AC / DC magnetic field mechanism forms a 45° angle with the substrate 15, with the magnetic field axis passing through the center of the molten pool, ensuring that the liquid metal in each region of the molten pool is subjected to the Lorentz force, preventing uneven magnetic field action and ensuring comprehensive molten pool stirring. The AC / DC magnetic field mechanism and the swing rod 21 are adjustable, allowing for fine-tuning of the angle between the magnetic field mechanism and the substrate 15 according to process parameters such as the thickness of the substrate 15, wire diameter, and additive layer thickness, ensuring optimal magnetic field effect and adapting to different additive requirements. Precise angle control causes the arc to tilt and deflect regularly under the influence of the magnetic field, expanding the arc heating area, optimizing the heat distribution of the molten pool, and reducing overheating problems in the center of the molten pool.

[0051] In the embodiment provided by the present invention, the AC / DC magnetic field mechanism includes an iron core, a DC component, and an AC component. The iron core is a circular iron core 23, which is fixedly connected to the swing rod 21. The lower end of the circular iron core 23 is always at a 45° angle to the molten pool. The DC component includes an inner cylinder 24 and an internal excitation coil 27. The inner cylinder 24 is sleeved on the outside of the circular iron core 23, and the internal excitation coil 27 is wound around the outer wall of the inner cylinder. The internal excitation coil 27 is electrically connected to an external DC power supply 12. The upper end of the inner cylinder 24 is provided with three circumferentially evenly distributed small screw holes 25. The inner cylinder 24 is fixed to the circular iron core 23 by small bolts 30. The inner cylinder 24 is provided with a machining notch 26, through which the internal excitation coil 27 passes. The notch 26 is connected to the DC power supply 12; the AC component includes an outer cylinder 28 and an external excitation coil 29. The external excitation coil 29 is wound around the outer wall of the outer cylinder 28 and is electrically connected to the external AC power supply 13. The inner cylinder 24 is located inside the outer cylinder 28, and there is a gap between the inner wall of the outer cylinder 28 and the internal excitation coil 27. The upper end of the outer cylinder 28 is provided with three small screw holes 25 that are evenly distributed in the circumference and match the inner cylinder 24. The outer cylinder 28 is fixed to the circular iron core 23 by small bolts 30. The outer side of the external excitation coil 29 is wrapped with insulating rubber. The magnetic lines of force generated by the AC / DC magnetic field generating component are symmetrically distributed around the axis of the circular iron core 23.

[0052] DC power supply 12 supplies power to internal excitation coil 27, which generates a stable DC magnetic field. AC power supply 13 supplies power to external excitation coil 29, which generates an alternating AC magnetic field. The DC magnetic field and AC magnetic field are superimposed to form a slanted longitudinal AC-DC magnetic field, which is symmetrically distributed around the axis of circular iron core 23. Circular iron core 23 plays a magnetic field focusing role, enhancing the magnetic field strength and ensuring the directionality of magnetic field lines, so that the magnetic field can act precisely on the molten pool. Inner cylinder 24 and outer cylinder 28 are fixed to circular iron core 23 by small bolts 30 to ensure the winding stability of the excitation coil. Processed notch 26 realizes a reliable connection between the excitation coil and the power supply. Insulating rubber prevents leakage and short circuit problems in external excitation coil 29. The gap between outer cylinder 28 and internal excitation coil 27 prevents structural compression caused by heat expansion of the excitation coil during operation.

[0053] This invention employs a structure of a circular iron core 23 and inner and outer double-layer excitation coils to achieve the superposition of DC and AC magnetic fields. The stable DC magnetic field provides the basic Lorentz force for the molten pool, while the alternating AC magnetic field causes the Lorentz force to change periodically, continuously stirring the molten pool and promoting the overflow of bubbles and the uniform distribution of alloying elements. The magnetic focusing effect of the circular iron core 23 increases the magnetic field strength and reduces magnetic field loss, allowing the magnetic field to effectively act on the molten pool area. The symmetrical distribution of magnetic field lines ensures the uniformity of the magnetic field effect within the molten pool. The inner cylinder 24 and outer cylinder 28 are circumferentially fixed by small bolts 30, ensuring a stable connection and effectively preventing interference during the additive manufacturing process. The coil offset caused by vibration is prevented, ensuring the stability of the magnetic field parameters. The notch 26 facilitates the arrangement of the excitation coil leads, preventing the leads from getting tangled and affecting the movement of the mechanism. The insulating rubber enhances the electrical safety of the mechanism and prevents equipment failure caused by leakage of the excitation coil. The gap between the outer cylinder 28 and the inner excitation coil 27 provides space for the thermal expansion of the excitation coil during operation, preventing the coil from being damaged by compression and extending the service life of the mechanism. The lower end of the circular iron core 23 is always aligned with the molten pool at 45°, ensuring that the magnetic field always acts on the molten pool at the optimal angle. Even if the magnetic field unit swings back and forth, it can maintain the effective effect of the magnetic field on the molten pool.

[0054] In the embodiments provided by the present invention, the winding height of the internal excitation coil 27 and the external excitation coil 29 is between 70mm and 80mm, the effective winding height of the inner cylinder 24 and the outer cylinder 28 is 80mm, and the number of winding coil turns of the inner cylinder 24 and the outer cylinder 28 is 100-150 turns.

[0055] The winding height of the excitation coil is limited to 70mm-80mm, with an effective winding height of 80mm, ensuring that the excitation coil has sufficient winding length and that the generated magnetic field has a certain range of influence, completely covering the molten pool area. The number of coil turns is designed to be 100-150 turns. By adjusting the number of turns and coordinating with the power supply current parameters, the magnetic field strength can be flexibly controlled to meet the magnetic field strength requirements of different additive manufacturing processes.

[0056] The 70mm-80mm coil winding height of this invention has been experimentally verified to ensure that the magnetic field's effective range completely covers the molten pool, avoiding insufficient magnetic field range due to excessively short coil height, which would prevent effective control of the liquid metal at the edge of the molten pool. The effective winding height of 80mm maximizes the use of the winding space of the inner cylinder 24 / outer cylinder 28, ensuring magnetic field strength within limited structural dimensions, making the device structure compact, and avoiding excessively large mechanism volume due to excessively long coils. The 100-150 turns of the wound coil provide sufficient margin for magnetic field strength control. By increasing / decreasing the number of turns and adjusting the power supply current, a magnetic field strength range of 5mT-30mT can be achieved, adapting to the process requirements of different metal materials and different additive layer thicknesses. The uniform coil height and number of turns design ensures the superposition effect of the magnetic fields of the internal and external excitation coils 29, avoiding magnetic field disturbances caused by inconsistent coil parameters, and ensuring the stability of the AC and DC magnetic fields.

[0057] In the embodiments provided by the present invention, the operating current provided by the DC power supply 12 and the AC power supply 13 is between 1A and 5A, the steady DC magnetic field strength generated by the AC / DC magnetic field unit 6 is 5mT-30mT, and the AC magnetic field strength is 5mT-30mT.

[0058] The output current of DC power supply 12 and AC power supply 13 directly determines the magnetomotive force of the excitation coil. By limiting the power supply current to 1A-5A and matching it with 100-150 turns of coil, the strength of both the DC magnetic field and the AC magnetic field can be controlled between 5mT and 30mT. After the DC magnetic field and the AC magnetic field are superimposed, an adjustable longitudinal AC-DC magnetic field is formed. By adjusting the power supply current, the magnetic field strength can be precisely controlled, thereby changing the magnitude of the Lorentz force on the liquid metal in the molten pool.

[0059] The 1A-5A power supply operating current of this invention is within a safe current range, avoiding excessive current that could cause severe overheating and burnout of the excitation coil, while simultaneously reducing the electrical energy consumption of the equipment and ensuring the safety and energy efficiency of the mechanism. The magnetic field strength range of 5mT-30mT has been experimentally verified as the optimal range for controlling the additive manufacturing molten pool of the arc fuse. This range avoids both insufficient Lorentz force due to insufficient magnetic field strength, which would prevent effective stirring of the molten pool and control of the arc morphology, and excessive magnetic field strength, which would cause excessively violent molten pool flow, resulting in molten pool splashing and a rough forming surface. The DC and AC magnetic field strengths are independently adjustable, allowing for flexible adjustment of the DC / AC magnetic field strength ratio according to the additive manufacturing process requirements, achieving precise control of the molten pool effect. For example, increasing the DC magnetic field strength can enhance the basic stirring of the molten pool, while increasing the AC magnetic field strength can improve the periodicity of molten pool stirring. The power supply current and magnetic field strength are linearly correlated, and precise control of the magnetic field strength can be achieved by adjusting the power supply current. The operation is simple, requiring no complex mechanical adjustments, thus improving process debugging efficiency.

[0060] In the embodiments provided by the present invention, the ultrasonic vibration unit includes an ultrasonic vibration generator 7 and an ultrasonic vibration mechanism 10. The ultrasonic vibration mechanism 10 is fixed on the worktable 14 and is in close contact with the substrate 15 placed on the worktable 14. The ultrasonic vibration mechanism 10 is electrically connected to the ultrasonic vibration generator 7. The working frequency of the ultrasonic vibration unit is between 20KHz and 30KHz, the amplitude is between 40um and 50um, and the ultrasonic vibration power is between 500W and 1500W.

[0061] The ultrasonic vibration generator 7 converts the power frequency AC power into high frequency AC power, providing a high frequency drive signal for the ultrasonic vibration mechanism 10. The ultrasonic vibration mechanism 10 converts the electrical signal into mechanical ultrasonic vibration, and through close contact with the substrate 15, transmits the ultrasonic vibration along the substrate 15 to the molten pool area of ​​the additive manufacturing process. The ultrasonic vibration generates cavitation effect and acoustic flow effect in the molten pool. The cavitation effect refers to the generation of a large number of tiny bubbles in the molten pool. When the bubbles burst, they generate micro-shock waves, which break up the coarse dendrites in the molten pool. The acoustic flow effect refers to the ultrasonic vibration driving the liquid metal in the molten pool to flow in a directional manner, promoting the stirring of the molten pool and the uniform distribution of alloying elements.

[0062] The 20kHz-30kHz operating frequency and 40µm-50µm amplitude of this invention are the optimal ultrasonic parameters for metal additive manufacturing. Experimental verification shows that this parameter range can generate significant cavitation and acoustic flow effects within the molten pool, effectively breaking dendrites and stirring the molten pool without causing excessive molten pool splashing due to excessive vibration. The 500W-1500W power range can be flexibly adjusted according to the substrate 15 thickness and molten pool size to adapt to different additive manufacturing processes, ensuring that ultrasonic vibration can be effectively transmitted to the molten pool and avoiding excessively rapid vibration attenuation due to insufficient power, thus failing to act on the molten pool. The ultrasonic vibration mechanism 10 and... The substrate 15 is in close contact, resulting in high vibration transmission efficiency, reduced vibration loss, and ensuring the effectiveness of ultrasonic action within the molten pool. The ultrasonic vibration and the AC / DC magnetic field work synergistically, with the Lorentz force generated by the magnetic field promoting molten pool flow. The cavitation and acoustic flow effects of the ultrasonic vibration further enhance molten pool stirring and grain refinement. The combination of these two factors makes the bubbles in the molten pool overflow more thoroughly and the grains finer, significantly improving the density of the deposited layer 22. The ultrasonic vibration is applied from the end of the substrate 15 and acts on the molten pool in a non-contact manner, without interfering with the operation of the CMT arc welding gun 5 or causing physical damage to the deposited layer 22, thus ensuring the continuity of the additive manufacturing process.

[0063] In the embodiment provided by the present invention, the mechanical impact unit includes a mechanical impact head 11 and a mechanical impact generator 9. The mechanical impact head 11 is fixed on the second robotic arm and is electrically connected to the mechanical impact generator 9. The operating frequency of the mechanical impact unit is 20KHz-30KHz, the amplitude is 40μm-50μm, and the power of the mechanical impact head 11 is 1000W-2000W.

[0064] The mechanical impact generator 9 provides high-frequency driving power to the mechanical impact head 11, causing the mechanical impact head 11 to generate high-frequency mechanical vibration. The second robot 8 drives the mechanical impact head 11 to move in real time along the additive manufacturing path, so that the mechanical impact head 11 applies high-frequency micro-amplitude mechanical impact to the surface of the just-solidified or semi-solidified deposition layer 22 during the formation of the deposition layer 22. The force of the mechanical impact is transmitted to the interior of the deposition layer 22, causing the deposition layer 22 to undergo micro-plastic deformation, releasing the thermal stress generated during the additive manufacturing process, and breaking the coarse grains in the deposition layer 22 to promote the formation of fine grains.

[0065] The 20kHz-30kHz operating frequency and 40μm-50μm amplitude of this invention are matched with the parameters of the ultrasonic vibration unit to achieve frequency coordination of multiple energy fields, avoiding resonance problems caused by frequency differences and ensuring the stability of the device. The 1000W-2000W impact head power ensures that the mechanical impact force can be effectively transmitted to the interior of the deposition layer 22, realizing stress release and grain refinement, while avoiding deformation and surface damage of the deposition layer 22 due to excessive power. The second robot 8 drives the mechanical impact head 11 to perform conformal impact, which can accurately adjust the impact position according to the outer contour of the deposition layer 22, ensuring that all areas of the deposition layer 22 are subjected to mechanical impact, avoiding stress concentration and uneven structure. The mechanical impact acts on the newly solidified / The semi-solidified deposition layer 22 exhibits good plasticity, making micro-plastic deformation easier to achieve and resulting in better stress release. Simultaneously, it effectively breaks up coarse nascent grains, refines the microstructure, and enhances the strength and toughness of the deposition layer 22. Mechanical impact, AC / DC magnetic fields, and ultrasonic vibration form a three-level synergistic control system: the magnetic field controls the molten pool flow, ultrasonic waves refine the molten pool grains, and mechanical impact releases stress in the deposition layer 22 and further refines the grains. This control over the entire process from molten pool solidification to the formation of the deposition layer 22 completely solves the problems of coarse microstructure, stress accumulation, and numerous defects inherent in traditional additive manufacturing. The mechanical impact head 11 is fixed to the second robotic arm, offering high motion precision and allowing for accurate control of impact force and position, adapting to the conformal impact requirements of complex structural components.

[0066] The present invention also provides an additive manufacturing method for electric arc fuses, comprising: The surface of the substrate 15 is sanded with sandpaper and cleaned with alcohol. The substrate 15 and the ultrasonic vibration mechanism 10 are fixed on the worktable 14. The contact position of the ultrasonic vibration mechanism 10 is adjusted so that the ultrasonic vibration mechanism 10 is close to the substrate 15. Turn on the power to apply ultrasonic vibration to the substrate 15 by the ultrasonic vibration mechanism 10, and transmit the ultrasonic waves to the substrate 15; make the AC / DC magnetic field mechanism generate DC magnetic field and AC magnetic field, and make the swing mechanism drive the AC / DC magnetic field mechanism to perform periodic reciprocating swing. The CMT arc welding gun 5 is turned on to perform additive manufacturing on the substrate 15. After the additive manufacturing of this layer is completed, the CMT arc welding gun 5 continues to perform the next layer deposition additive manufacturing according to the preset additive manufacturing path until it is completed.

[0067] Specifically: S1, Pretreatment and Fixation of Substrate 15 The surface of the substrate 15 is polished step by step with sandpaper to remove the oxide layer and rust. Then, the surface of the polished substrate 15 is cleaned with anhydrous ethanol to remove surface oil and impurities, completing the degreasing treatment. The pretreated substrate 15 is fixed in the preset position of the worktable 14, and the ultrasonic vibration mechanism 10 of the ultrasonic vibration unit is adjusted to make the ultrasonic vibration mechanism 10 in close contact with the bottom surface of the substrate 15 to ensure vibration transmission efficiency. The substrate 15 is preferably a 4-series aluminum alloy substrate 15, and the metal wire is preferably 4043 aluminum alloy welding wire with a diameter of 1.2 mm.

[0068] S2, Multi-energy field unit pre-start and parameter setting Turn on the power supply of each unit and start the ultrasonic vibration generator 7 so that the ultrasonic vibration mechanism 10 applies ultrasonic vibration with preset parameters to the substrate 15; turn on the DC power supply 12 and AC power supply 13 to supply power to the internal excitation coil 27 and the external excitation coil 29 respectively, so that the AC and DC magnetic field mechanism generates DC magnetic field and AC magnetic field of preset intensity; turn on the motor power supply 4 to drive the motor 18 to drive the swing rod 21 to rotate through the gear set 17, so that the AC and DC magnetic field mechanism performs periodic reciprocating swing within 0-80°, keeping the lower end of the circular iron core 23 at 45° and always corresponding to the preset position of the welding molten pool.

[0069] S3, additive manufacturing and multi-field synergy Pre-circuit shielding gas into the shielding gas channel of the CMT arc welding torch 5. The shielding gas is preferably argon with a purity of 99.9%. The argon flow rate is adjusted to 18L / min-20L / min. After pre-circuiting for 30 seconds, the air in the worktable 14 is exhausted to prevent metal oxidation during welding. Turn on the welding power supply 1 of the CMT arc welding torch 5, set the walking trajectory and speed of the first robot 3. The walking speed of the first robot 3 is 0.5m / min-1.5m / min. The first robotic arm drives the CMT arc welding torch 5 to move according to the preset trajectory and speed, and the melting and deposition of the wire begins. At the same time, turn on the mechanical impact generator 9, set the working parameters of the mechanical impact unit, and set the walking trajectory and speed of the second robot 8 so that the second robot 8 moves in sync with the first robot 3. The second robotic arm drives the mechanical impact head 11 to follow the arc additive path in real time and apply a following mechanical impact to the deposition layer 22 to achieve the synergistic effect of AC / DC magnetic field, ultrasonic vibration, mechanical impact multi-energy field and additive manufacturing process.

[0070] S4, Layer-by-layer deposition After the additive manufacturing of a single deposition layer 22 is completed, the first robot 3 drives the CMT arc welding gun 5 to automatically adjust to the welding position of the next layer according to the preset additive path and layer thickness, and continues to carry out the additive manufacturing of the next deposition layer 22. The multi-energy field unit remains in working state and continuously regulates the molten pool and deposition layer 22.

[0071] S5. Repeat forming until the component is complete. Repeat steps S3-S4, and perform deposition manufacturing layer by layer according to the preset three-dimensional model and additive path until the deposition layer 22 of the entire component is prepared, and a complete additively manufactured component is obtained.

[0072] This method is based on the pretreatment of substrate 15 to ensure the bonding strength between substrate 15 and deposition layer 22, and avoid defects such as incomplete fusion and porosity caused by impurities on the surface of substrate 15. The multi-energy field unit is pre-started to enable the AC and DC magnetic fields and ultrasonic vibrations to enter the working state in advance, ensuring that the multi-energy field can be effectively controlled at the beginning of additive manufacturing. The protective gas is pre-vented to remove air, avoiding oxidation of metal wire and molten pool at high temperature and improving the purity of deposition layer 22. During the additive manufacturing process, the dual robots realize the synchronous / follow-up control of CMT arc welding gun 5, magnetic field unit and mechanical impact head 11. The multi-energy field works synergistically from molten pool solidification (magnetic field, ultrasound) to deposition layer 22 forming (mechanical impact) to achieve the forming of three-dimensional components by deposition layer by layer, ensuring the stability and forming quality of the additive process throughout.

[0073] The substrate 15 of this invention undergoes pretreatment with polishing and alcohol cleaning to effectively remove oxide layers and oil stains, ensuring the metallurgical bond between the substrate 15 and the deposition layer 22 and avoiding interface defects such as incomplete fusion and porosity. The multi-energy field unit is pre-activated, ensuring the magnetic field and ultrasound are in a stable working state at the start of additive manufacturing, avoiding poor first-layer forming quality due to delayed energy field activation. A 30-second pre-circulation of protective gas completely removes air from the welding area, preventing oxidation of active metals such as aluminum alloys at high temperatures and improving the purity and mechanical properties of the deposition layer 22. The walking speed of the two robots is synchronously controlled between 0.5 m / min and 1.5 m / min, which is the optimal speed for arc wire additive manufacturing. This ensures sufficient melting of the wire while avoiding overheating of the molten pool and coarse grains due to excessively slow speed, while also ensuring precise follow-up movement of the mechanical impact head 11 for impact. The argon gas flow rate is controlled between 18 L / min and 20 L / min. It can form a stable protective gas curtain, completely covering the molten pool and arc area, avoiding insufficient protection due to insufficient gas flow or excessive gas flow leading to rapid cooling of the molten pool and poor forming. The multi-energy field works in synergy with the additive manufacturing process, achieving full-process optimization from molten pool flow control to grain refinement to stress release, completely solving the technical problems of coarse microstructure, low forming quality, numerous defects, and poor mechanical properties in traditional WAAM technology. The method is simple, and the process parameters can be flexibly adjusted to adapt to the additive manufacturing needs of different metal materials and structural parts. It is highly automated, with precise control of trajectory and speed through robots, reducing human intervention and improving production efficiency and component consistency. During the layer-by-layer deposition process, the multi-energy field works continuously to ensure the forming quality and microstructure uniformity of each deposition layer, avoiding problems such as poor interlayer bonding and stress accumulation caused by interruption of interlayer energy field, thus improving the overall mechanical properties of the component.

[0074] It should be noted that any parts not disclosed or specifically described in this invention are existing technology or conventional configurations, and their specific structures and working principles will not be elaborated further. In this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element.

[0075] Although embodiments of the present invention have been disclosed above, they are not limited to the applications listed in the specification and embodiments. It can be applied to various fields suitable for the present invention. Other modifications can be readily implemented by those skilled in the art. Therefore, without departing from the general concept defined by the claims and their equivalents, the present invention is not limited to the specific details and examples shown and described herein.

Claims

1. An additive manufacturing apparatus employing a multi-energy field assisted arc fuse wire, characterized in that, include: Workbench; An additive manufacturing unit includes an arc welding gun fixed to a first robotic arm; The AC / DC magnetic field unit includes an AC / DC magnetic field mechanism, a swing mechanism, and a connecting frame. The connecting frame is connected to a first robotic arm, the swing mechanism is connected to the connecting frame, and the AC / DC magnetic field mechanism is connected to the swing mechanism. The swing mechanism is used to move the AC / DC magnetic field mechanism closer to or away from the welding position of the arc welding torch. The DC magnetic field and AC magnetic field generated by the AC / DC magnetic field unit act on the welding arc and molten pool, regulating the flow of the molten pool and the arc shape through Lorentz force, and continuously stirring the molten pool. The swing mechanism includes a motor and a swing rod. The motor is fixed above the connecting frame, and the swing rod is connected to the output shaft of the motor. The AC / DC magnetic field mechanism and the swing mechanism are connected to the swing mechanism. The motor, via a swing arm, rotates to move an AC / DC magnetic field mechanism closer to or further away from the welding position of the arc welding gun. The AC / DC magnetic field mechanism includes an iron core, a DC component, and an AC component. The iron core is connected to the swing arm, and the lower end of the iron core is always at a 45° angle to the molten pool. The DC component includes an inner cylinder sleeved on the iron core and an internal excitation coil wound around the outer wall of the inner cylinder. The internal excitation coil is connected to a DC power supply. The AC component includes an outer cylinder and an external excitation coil wound around the outer wall of the outer cylinder. The external excitation coil is connected to an AC power supply. The inner cylinder is located inside the outer cylinder, and there is a gap between the inner wall of the outer cylinder and the internal excitation coil. An ultrasonic vibration unit is fixed on a worktable and is used to apply ultrasonic vibration to a substrate. The ultrasonic vibration unit includes an ultrasonic vibration generator and an ultrasonic vibration mechanism. The ultrasonic vibration mechanism is fixed on the worktable and acts on the substrate. The ultrasonic vibration generator is used to control the working frequency and amplitude of the ultrasonic vibration mechanism. A mechanical impact unit, fixed on a second robotic arm, is used to perform accompanying mechanical impact on the deposited layer of the welded part. The mechanical impact unit includes a mechanical impact head and a mechanical impact generator connected to the mechanical impact head. The mechanical impact head is fixed on the second robotic arm, and the mechanical impact generator is used to control the frequency and amplitude of the mechanical impact head.

2. The additive manufacturing apparatus for multi-energy field assisted arc fuse wire according to claim 1, characterized in that, A gear set is provided between the motor and the swing arm.

3. The additive manufacturing apparatus for multi-energy field assisted arc fuse wire according to claim 1, characterized in that, The rotation angle of the swing arm is between 0 and 80 degrees.

4. The additive manufacturing apparatus for multi-energy field assisted arc fuse wire according to claim 1, characterized in that, The winding height of the internal excitation coil and the external excitation coil is between 70mm and 80mm.

5. The additive manufacturing apparatus for multi-energy field assisted arc fuse wire according to claim 1, characterized in that, The current provided by both the DC power supply and the AC power supply is between 1A and 5A.

6. A method for additive manufacturing of electric arc fuses, using a multi-energy field assisted electric arc fuse additive manufacturing apparatus according to any one of claims 1 to 5, characterized in that, include: The substrate surface is sanded with sandpaper and cleaned with alcohol. The substrate is then fixed on the worktable. The contact position of the ultrasonic vibration unit is adjusted so that the ultrasonic vibration unit is close to the substrate. Turn on the power to apply ultrasonic vibration to the substrate by the ultrasonic vibration unit, which in turn generates a DC magnetic field and an AC magnetic field by the AC / DC magnetic field mechanism. This causes the oscillating mechanism to drive the AC / DC magnetic field mechanism to oscillate periodically, thereby controlling the flow of the molten pool and the shape of the arc and the molten pool through the Lorentz force, and continuously stirring the molten pool. The arc welding gun is turned on to perform additive manufacturing on the substrate. After the additive manufacturing of this layer is completed, the arc welding gun continues to deposit the next layer of additive manufacturing according to the preset additive path until the process is completed.

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