A microwave additive manufacturing system and method

Abstract

This invention provides a microwave additive manufacturing system and method, belonging to the field of additive manufacturing technology. The invention includes a three-axis motion system, a wire feeding system, a microwave system, and a control system. A metal wire is passed through a microwave resonant cavity and a waveguide, extending the wire tip to the waveguide outlet to form a needle-like structure. Microwave-induced partial discharge at the wire tip generates heat, melting the metal wire. Wire feeding and microwave output are synchronously controlled in a pulsed manner to achieve layer-by-layer deposition. This invention uses microwaves as the heating source, leveraging their rapid heating and high energy efficiency to achieve rapid melting and deposition of the metal wire. Compared to existing heat sources such as lasers and electron beams, microwave equipment has a simpler structure, lower cost, lower energy consumption, and is not limited by the type of metal material.

Description

Technical Field

[0001] This invention relates to the field of additive manufacturing technology, and in particular to a microwave additive manufacturing system and method. Background Technology

[0002] Additive manufacturing is an advanced manufacturing technology that uses three-dimensional model data to form components by layering materials. Existing metal additive manufacturing can be mainly divided into four categories based on the type of heat source: laser, electron beam, electric arc, and thermoforming.

[0003] Among them, laser additive manufacturing has high forming accuracy, but the equipment is expensive and energy consumption is high, resulting in high overall costs; electron beam additive manufacturing has moderate efficiency, but requires a vacuum environment, has strict working conditions, and has high costs; electric arc additive manufacturing has high forming efficiency, but poor heating stability, low forming accuracy, poor component quality, and high process control; thermomelting additive manufacturing requires preheating and melting a large amount of metal material before extrusion forming, requiring large-volume metal material melting equipment, resulting in high energy consumption and high costs.

[0004] In summary, existing metal additive manufacturing methods using various heat sources all have their own shortcomings. Therefore, developing low-cost metal additive manufacturing methods remains essential. Microwave heating technology can achieve rapid heating of metal materials, and its equipment structure is simple, with low energy consumption and maintenance costs. It is a low-cost, high-performance heating method that can effectively compensate for the technical shortcomings of traditional additive manufacturing and has broad application prospects. Summary of the Invention

[0005] In view of this, to address the aforementioned shortcomings of existing metal additive manufacturing methods using various heat sources, this invention provides a microwave additive manufacturing system and method. A metal wire is threaded through a microwave resonant cavity and a waveguide, extending the wire's end to the waveguide outlet to form a needle-like structure. Microwave-induced partial discharge at the wire's end generates heat, melting the metal wire. Wire feeding and microwave output are synchronously controlled in a pulsed manner to achieve layer-by-layer deposition. This invention uses microwaves as the heating source, leveraging their rapid heating and high energy efficiency to achieve rapid melting and deposition of the metal wire. Compared to existing heat sources such as lasers and electron beams, microwave equipment has a simpler structure, lower cost, lower energy consumption, and is not limited by the type of metal material.

[0006] To achieve the above objectives, the present invention provides the following technical solution: In a first aspect, the present invention provides a microwave additive manufacturing system, characterized in that it comprises: A three-axis motion system is used to achieve positioning and displacement control of waveguides and metal wires; A wire feeding system is used to transport the metal wire. A microwave system includes a microwave generator, a waveguide, and a microwave resonant cavity. The microwave generator is connected to the microwave resonant cavity, and the waveguide is connected to the microwave resonant cavity. A metal wire passes through the microwave resonant cavity and the waveguide, and the end of the metal wire extends to the outlet of the waveguide. Microwaves generated by the microwave generator are conducted through the microwave resonant cavity and the waveguide to the end of the metal wire, inducing the end of the metal wire to discharge and melt. The control system is electrically connected to the three-axis motion system, the wire feeding system, and the microwave system, respectively, and is used to control the coordinated operation of the three-axis motion system, the wire feeding system, and the microwave system.

[0007] Secondly, the present invention provides a microwave additive manufacturing method, implemented using the aforementioned microwave additive manufacturing system, comprising the following steps: Step S1: Pass a metal wire through the microwave resonant cavity and the waveguide connected to the microwave resonant cavity, so that the end of the metal wire extends to the outlet of the waveguide. Step S2: Feed microwaves into the microwave resonant cavity, so that the microwaves are conducted through the waveguide to the end of the metal wire, inducing the end of the metal wire to discharge and melt; Step S3: Control the metal wire to be delivered to the outlet of the waveguide in a pulsed manner, and simultaneously control the molten metal wire to be deposited and formed according to a preset path.

[0008] Compared with the prior art, the present invention has the following beneficial effects: (1) This invention uses microwaves as a novel heating source for additive manufacturing. It utilizes the characteristics of microwave heating to quickly heat up and achieve the melting and deposition of metal wires, providing a new method and path for energy-saving, environmentally friendly and low-consumption manufacturing.

[0009] (2) Compared with traditional additive manufacturing heat sources, the microwave additive manufacturing system of the present invention has low cost and high efficiency, and is not limited by the type of metal material, providing a new low-cost solution for additive manufacturing of metal wires. Attached Figure Description

[0010] Figure 1 This is a schematic diagram of the overall layout of the present invention.

[0011] Figure 2 This is a partial schematic diagram of the wire feeding system and microwave resonant cavity of the present invention.

[0012] Figure 3 Partial view of metal wires manufactured using microwave additive manufacturing.

[0013] In the diagram, 1. Metal printing platform; 2. Waveguide; 3. Microwave resonant cavity; 4. Z-axis vertical lifting mechanism; 5. X-axis horizontal motion mechanism; 6. Gantry; 7. Wire feeding actuator; 8. Optical axis linear guide mechanism; 9. Y-axis forward and backward motion mechanism; 10. Installation and support module; 11. Wire guide channel; 12. Wire drive system; 13. Glass tube; 14. Waveguide inner guide tube; 15. Waveguide outer wall; 16. Shell; 17. Waveguide gap space; 18. Support frame; 19. Sealing element; 20. Microwave absorbing buffer cavity; 21. Metal wire; 22. First motor; 23. Lead screw; 24. Second motor; 25. First belt; 26. Third motor. Detailed Implementation

[0014] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0015] like Figure 1-3 As shown, the present invention provides a microwave additive manufacturing system, comprising: The three-axis motion system is used to achieve the positioning and displacement control of the waveguide 2 and the metal wire 21.

[0016] A wire feeding system for conveying the metal wire.

[0017] The microwave system includes a microwave generator, a waveguide 2, and a microwave resonant cavity 3. The microwave generator is connected to the microwave resonant cavity 3, and the waveguide 2 is connected to the microwave resonant cavity 3. A metal wire 21 passes through the microwave resonant cavity 3 and the waveguide 2, and the end of the metal wire 21 extends to the outlet of the waveguide 2. The microwaves generated by the microwave generator are conducted through the microwave resonant cavity and the waveguide 2 to the end of the metal wire 21, inducing the end of the metal wire 21 to discharge and melt.

[0018] The control system is electrically connected to the three-axis motion system, the wire feeding system, and the microwave system, respectively, and is used to control the coordinated operation of the three-axis motion system, the wire feeding system, and the microwave system.

[0019] The microwave additive manufacturing system provided by this invention delivers a metal wire 21 to the outlet of a waveguide 2 via a wire feeding system. A three-axis motion system controls the positioning and displacement of the waveguide 2 and the metal wire 21. The control system synchronously controls the wire feeding speed, microwave output power, and motion trajectory. Its working principle is as follows: a microwave generator produces microwaves, which are conducted through a microwave resonant cavity 3 and a waveguide 2 to the end of the metal wire 21. Under microwave induction, electrons accumulate and discharge at the end of the metal wire 21, and the discharge energy melts the metal wire. Addressing the problems of expensive laser additive manufacturing equipment, the need for a vacuum environment in electron beam additive manufacturing, poor heating stability in arc additive manufacturing, and the need for large-volume melting equipment in thermal fusion additive manufacturing, this system uses microwaves as the heating source. Microwave equipment has a simple structure, requires no vacuum environment, has good heating stability, and does not require large-volume melting equipment, thus reducing equipment costs and energy consumption. Microwave equipment has a simple structure, low cost, low energy consumption, requires no vacuum environment, and is not limited by the type of metal material.

[0020] In one specific embodiment of the present invention, the metal wire 21 can be a conductive metal material such as aluminum alloy wire or titanium alloy wire. The diameter is preferably 0.5-1.5 mm.

[0021] In one specific embodiment of the present invention, such as Figure 3 As shown, the waveguide 2 includes a coaxially assembled inner waveguide 14 and an outer waveguide wall 15. The outer waveguide wall 15 is preferably mounted on the housing 16 of the microwave resonant cavity 3. A waveguide gap space 17 is formed between the inner waveguide 14 and the outer waveguide wall 15, and microwaves are conducted along the waveguide gap space 17. A tapered structure is provided at the lower end outlet of the inner waveguide 14. A metal wire 21 passes through the center of the inner waveguide 14 and combines with the inner waveguide 14 at the outlet to form a needle tip structure. The needle tip structure highly concentrates the electric field intensity at the end of the metal wire, promoting electron accumulation and discharge. In this embodiment, the metal wire 21 passes through the center of the inner waveguide 14, forming a needle tip at the tapered outlet, and microwaves are conducted along the waveguide gap space 17 to the needle tip. In this embodiment, the needle tip structure highly concentrates microwave energy at the end of the wire, solving the problem of microwave energy dispersion and difficulty in effectively melting the metal wire under ordinary structures. The coaxial waveguide structure ensures the uniformity and stability of microwave conduction. The needle tip structure enhances the local electric field and reduces the microwave power required for melting; the coaxial waveguide has a simple structure and high microwave transmission efficiency.

[0022] In one specific embodiment of the present invention, the inner conduit 14 of the waveguide is made of copper. Copper has good electrical conductivity, which facilitates the accumulation of electrons on the inner conduit of the waveguide and their conduction to the needle tip, thereby enhancing the discharge effect. Furthermore, copper is low in cost, has good electrical conductivity, and is easy to process.

[0023] In one specific embodiment of the present invention, such as Figure 3 As shown, a support frame 18 is assembled between the outer wall 15 of the waveguide and the inner duct 14 of the waveguide. The support frame 18 serves as a limiting support, does not obstruct or affect microwave transmission, and ensures the overall coaxial fixation of the waveguide. This solves the problem of difficulty in ensuring coaxiality between the inner duct 14 and the outer wall 15 of the waveguide, ensures a stable microwave transmission path, and avoids a decrease in microwave transmission efficiency due to structural deformation. The support frame 18 has a simple structure, does not affect microwave transmission, and ensures long-term stable operation of the waveguide.

[0024] In one specific embodiment of the present invention, such as Figure 3 As shown, the upper end of the waveguide inner guide tube 14 extends into the microwave resonant cavity 3 and is axially connected to the lower end of the glass tube 13. The glass tube 13 supports and guides the metal wire 21 (the metal wire enters the waveguide inner guide tube from the glass tube, and the glass tube guides and supports the wire to prevent it from shifting or getting stuck), and microwaves can pass through the glass tube 13 to act on the metal wire 21. Specifically, the upper end of the waveguide inner guide tube 14 extends into the microwave resonant cavity 3 to a certain length, ensuring that microwaves can act on the inner guide tube to promote the accumulation of electrons from the upper part of the inner guide tube to the needle tip. The waveguide inner guide tube 14 is axially connected to the lower end of the glass tube 13. The glass tube 13 supports and guides the metal wire 21, and microwaves can pass through the glass tube to act on the metal wire 21, facilitating the accumulation of electrons in the metal wire towards the needle tip under microwave induction, forming a needle tip effect. Under microwave induction, electrons accumulate and discharge at the end of the metal wire 21, providing a heat source for the melting of the metal wire 21.

[0025] In one specific embodiment of the present invention, the upper end of the glass tube 13 is axially connected to the sealing element 19, the sealing element 19 is installed on the housing 16 of the microwave resonant cavity 3, and the metal wire 21 passes through the sealing element 19 and enters the microwave resonant cavity 3; a wave-absorbing buffer cavity 20 is provided at the inner wall of the shaft hole of the sealing element 19 to absorb the microwave energy leaking out along the gap between the metal wire 21 and the sealing element 19, so as to avoid microwave dissipation and loss.

[0026] In one specific embodiment of the present invention, the control system includes a function generator, which outputs pulse signals and transmits information to the wire feeding system and the microwave system to synchronously control the wire feeding speed of the wire feeding system and the output power of the microwave system. (Specifically, the function generator simultaneously outputs two phase-adjustable synchronous pulse signals. The first signal serves as the speed setpoint signal for the wire feeding drive motor, directly controlling the instantaneous rotational speed of the wire feeding roller. The second signal serves as the excitation level of the microwave source anode modulation signal, used to control the rise and fall edges and bandwidth of the microwave output power. The two signals share a common reference clock, and by adjusting the phase, the start time of the microwave power pulse is advanced by a time increment compared to the start time of the wire feeding pulse, ensuring that microwave heating is synchronously established when the wire end reaches the molten pool.) This ensures that both the wire feeding speed and the microwave power are in pulse form and phase-coordinated. The microwave system receives the phase timing control command issued by the function generator and, by inputting a specific function timing signal, controls the microwave system to emit microwaves of a certain energy. This solves the problem of uneven melting caused by asynchronous wire feeding and heating. Pulse synchronous control ensures that the filament is fed and heated only when melting is required, avoiding energy waste and an excessively large heat-affected zone caused by continuous heating. This improves energy utilization efficiency, provides high control precision, and results in good molding quality.

[0027] In one specific embodiment of the present invention, such as Figure 2 As shown, the wire feeding system includes a wire driving system 12 and a wire feeding actuator 7; the wire feeding actuator 7 is fixed on the mounting and support module 10 and includes a wire guiding channel 11; the wire driving system 12 is used to receive phase timing control commands issued by the function generator to realize the wire feeding speed in a pulse form. In this embodiment, the wire driving system 12 drives the metal wire 21 forward along the wire guiding channel 11, and the wire feeding drive control module controls the pulse change of the feeding speed according to the pulse command. This solves the problem of precise control of the wire feeding speed. Pulsed wire feeding is achieved through phase timing control commands, which is synchronized with the microwave pulse output to ensure the coordination of melting and deposition. This embodiment has high wire feeding accuracy, fast response speed, and good synergy with the microwave system.

[0028] In one specific embodiment of the present invention, exemplarily, such as Figure 1 As shown, the three-axis motion system is mounted on the base and the gantry 6. The gantry 6 is mounted on the base. The three-axis motion system includes... The X-axis lateral motion mechanism 5, the Y-axis forward / backward motion mechanism 9, and the Z-axis vertical lifting motion mechanism 4 are used to realize the movement of the waveguide 2 and the metal wire 21 in the X, Y, and Z axes, respectively. The optical axis linear guide mechanism 8 guides the movement. The three-axis motion control module controls the movement of the X-axis lateral motion mechanism 5, the Y-axis forward / backward motion mechanism 9, and the Z-axis vertical lifting motion mechanism 4. The Z-axis vertical lifting motion mechanism 4 drives the lead screws 23 at both ends of the gantry 6 to rotate via the first motor 22, thereby causing the optical axis linear guide mechanism 8 to slide along the vertical direction of the gantry 6 and to rise and fall vertically along the gantry 6. The metal printing platform 1 is connected to the Y-axis forward / backward motion mechanism 9, and is driven by a belt (not shown in the figure) via a third motor 26, which moves the metal printing platform 1 back and forth under the action of the Y-axis forward / backward motion mechanism 9. The X-axis lateral motion mechanism 5 is mounted on the Z-axis vertical lifting motion mechanism 4 via the optical axis linear guide mechanism 8. The X-axis lateral motion mechanism 5 is horizontally mounted on the optical axis linear guide mechanism 8, and is driven by the second motor 24 to drive the first belt 25, which in turn drives the microwave system and wire feeding system mounted on the X-axis lateral motion mechanism 5 to move laterally. The three-axis motion control module receives commands from the control system and drives the X-axis lateral motion mechanism 5, the Y-axis forward / backward motion mechanism 9, and the Z-axis vertical lifting motion mechanism 4 to perform corresponding movements. It may include a motion controller, driver, encoder interface, etc., to achieve precise control of the speed, position, and acceleration of each axis. It is electrically connected to the control system, receives preset forming path data, and converts it into drive signals for each axis motion mechanism. This is existing technology and will not be described further here.

[0029] Under the control system's commands, the three-axis motion system moves along a preset forming path, causing the molten metal wire 21 to deposit on the metal printing platform 1 along the preset path. After a single layer is deposited, the printing platform descends by one layer thickness to begin the next layer deposition, and so on, layer by layer, until the additive manufacturing of the entire metal component is completed. The three-axis motion system enables precise positioning and displacement of the waveguide and metal wire in three-dimensional space, ensuring that the molten metal is deposited layer by layer along the preset path, thus guaranteeing forming accuracy. Its high motion accuracy allows for the forming of complex three-dimensional structures.

[0030] In one specific embodiment of the present invention, the output power of the microwave generator is preferably 300-1000W. The microwave frequency range is preferably 900MHz-2500MHz. When the power is preferably 300-500W, the operating frequency is preferably 2.45GHz. When the power is 501-1000W, the operating frequency is 915MHz.

[0031] The control system of this invention includes a main control unit, a function generator, and a detection feedback module. (The main control unit, as the control core, is responsible for setting overall process parameters, planning motion trajectories, and calculating pulse timing logic. It also sends synchronous control commands to the function generator. Simultaneously, the main control unit receives real-time monitoring data from the detection feedback module and makes online adjustments based on preset thresholds. The detection feedback module includes a temperature sensor and a power detection unit, which are used to collect the molten pool temperature and the actual microwave output power in real time. The collected signals are converted from analog to digital and fed back to the main control unit. The main control unit compares the feedback value with the target value and dynamically corrects the output pulse parameters of the function generator using a PID algorithm, thereby forming a closed-loop control link.) This control system can complete parameter setting, motion control, and status monitoring, and can control the three-axis motion system, wire feeding system, and microwave system. It may also include auxiliary components, including a protective gas system, a cooling system, and cleaning tools, to ensure safe operation of the equipment and molding quality.

[0032] The present invention also provides a microwave additive manufacturing method, implemented using the above-described microwave additive manufacturing system, comprising the following steps: Step S1: Pass the metal wire 21 through the microwave resonant cavity 3 and the waveguide 2 connected to the microwave resonant cavity 3, so that the end of the metal wire 21 extends to the outlet of the waveguide 2. Step S2: Feed microwaves into the microwave resonant cavity 3, so that the microwaves are conducted through the waveguide to the end of the metal wire 21, inducing the end of the metal wire 21 to generate discharge and melt. Step S3: Control the metal wire 21 to be delivered to the outlet of the waveguide 2 in a pulsed manner, while simultaneously controlling the molten metal wire 21 to be deposited and formed along a preset path. Specifically: Step 1: Provide a three-axis motion system, which includes a three-axis motion control module, an X-axis lateral motion mechanism 5, a Y-axis forward and backward motion mechanism 9, a Z-axis vertical lifting mechanism 4, and an optical axis linear guide mechanism 8, to achieve precise positioning and displacement control of the waveguide 2 and the metal wire 21.

[0033] Step 2: Provide a wire feeding system, which includes a wire feeding drive control module, a wire feeding actuator 7, and a metal wire 21. The wire feeding actuator 7 is fixed on the support module 10 and includes a wire guide channel 11 and a wire driving system 12. The wire driving system 12 receives phase timing control commands from a function generator, enabling the wire feeding speed to be pulsed to deliver the wire.

[0034] Step 3: Provide a microwave system, which includes a microwave generator, a waveguide 2, and a microwave resonant cavity 3. The microwave system receives phase timing control commands from the function generator and, by inputting specific function timing signals, controls the microwave system to emit microwaves of a certain energy.

[0035] Step 4: Provide a complete machine control system, which includes a main control unit, a function generator, and a detection feedback module. (The main control unit, as the system decision-making core, is used to pre-store and execute the process parameter table, dynamically call the corresponding parameter group according to the current processing layer, and send pulse timing setting instructions to the function generator. Simultaneously, the main control unit is also used to send motion trajectory coordinate instructions to the three-axis motion system to make the wire feeding actuator move along a preset path. After receiving the setting instructions from the main control unit, the function generator generates two phase-synchronized pulse signals to drive the wire feeding motor and the...) The power of the microwave system. The detection feedback module includes an infrared temperature sensor and a power detector, which are used to collect the melting temperature and the actual microwave output power in real time, respectively, and upload the collected signals to the main control unit after conditioning and conversion. The main control unit compares the real-time detection value with the preset target value. When the deviation exceeds the allowable range, it dynamically corrects the error through a PID algorithm and sends the pulse parameters to the function generator to ensure that the microwave heating and wire feeding melting processes are always dynamically matched. Thus, the whole machine control system forms a closed-loop control link, realizing the coordinated control of the three-axis motion system, the wire feeding system, and the microwave system.

[0036] Step 5: The pre-installed metal wire 21 exits from the wire feeding actuator 7 and enters the microwave resonant cavity 3, passing through the microwave resonant cavity 3 and the waveguide 2. The end of the metal wire 21 extends to the outlet of the waveguide 2, forming a needle tip effect. Under microwave induction, electrons accumulate and discharge at the end of the wire, providing a heat source for the melting of the wire.

[0037] Step 6: Start the whole machine control system, set the function generator to output pulse signal, and transmit the information to the wire drive system 12 and the microwave system. After receiving the signal, the microwave system adjusts the output power and frequency.

[0038] Step 7: Under the action of the pulse signal, the wire feeding actuator 7 delivers a metal wire 21 with a pulsed movement speed, and the microwave generator emits microwaves with pulsed power. Simultaneously, the metal wire 21 passes through the microwave resonant cavity 3 and the waveguide 2. The microwaves are reflected multiple times in the microwave resonant cavity 3 and enter the waveguide gap space 17 of the waveguide 2, and are transmitted to the end of the waveguide. Under the action of the microwaves, a large number of electrons are locally accumulated at the tip of the metal wire 21 output from the end of the waveguide 2, and a discharge occurs. Under the action of the discharge energy, the metal wire melts and is deposited on the base plate.

[0039] Step 8: The three-axis motion system moves according to the preset forming path under the command of the control system, so that the molten tip of the metal wire 21 is deposited on the metal printing platform 1 according to the preset path.

[0040] Step 9: Repeat step 8, layer by layer, until the additive manufacturing of the entire metal component is completed.

[0041] Step 10: After the molding operation is completed, shut down the microwave system, wire feeding system, three-axis motion system, function generator, and overall machine control system in sequence.

[0042] In summary, this invention uses microwaves as a novel heating source for additive manufacturing. By leveraging the rapid heating and high energy efficiency of microwaves, the melting and deposition of metal wires can be achieved quickly, providing a new method and path for energy-saving, environmentally friendly, and low-consumption manufacturing. Compared with traditional additive manufacturing heat sources, the microwave additive manufacturing system of this invention is low in cost, high in efficiency, and not limited by the type of metal material, providing a low-cost new solution for the additive manufacturing of metal wires.

[0043] The above description is merely a preferred embodiment of the present invention. However, the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention should be covered within the scope of protection of the present invention.

Claims

1. A microwave additive manufacturing system, characterized in that, include: A three-axis motion system is used to achieve positioning and displacement control of waveguides and metal wires; A wire feeding system is used to transport the metal wire. A microwave system includes a microwave generator, a waveguide, and a microwave resonant cavity. The microwave generator is connected to the microwave resonant cavity, and the waveguide is connected to the microwave resonant cavity. A metal wire passes through the microwave resonant cavity and the waveguide, and the end of the metal wire extends to the outlet of the waveguide. Microwaves generated by the microwave generator are conducted through the microwave resonant cavity and the waveguide to the end of the metal wire, inducing the end of the metal wire to discharge and melt. The control system is electrically connected to the three-axis motion system, the wire feeding system, and the microwave system, respectively, and is used to control the coordinated operation of the three-axis motion system, the wire feeding system, and the microwave system.

2. The microwave additive manufacturing system according to claim 1, characterized in that, The waveguide includes a coaxially assembled inner waveguide and an outer waveguide wall, with a waveguide gap space formed between the inner waveguide and the outer waveguide wall, and microwaves are propagated along the waveguide gap space; a tapered structure is provided at the lower end of the inner waveguide outlet, which is used to form a needle tip structure together with the metal wire.

3. The microwave additive manufacturing system according to claim 2, characterized in that, The inner conduit of the waveguide is made of copper.

4. The microwave additive manufacturing system according to claim 2, characterized in that, A support frame is assembled between the outer wall of the waveguide and the inner duct of the waveguide.

5. A microwave additive manufacturing system according to claim 2, characterized in that, The upper end of the inner conduit of the waveguide extends into the microwave resonant cavity and is axially connected to the lower end of the glass tube. The glass tube is used to support and guide the metal wire, and microwaves can pass through the glass tube to act on the metal wire.

6. The microwave additive manufacturing system according to claim 5, characterized in that, The upper end of the glass tube is axially connected to the sealing element, which is installed on the housing of the microwave resonant cavity. The metal wire passes through the sealing element and enters the microwave resonant cavity. An absorbing buffer cavity is provided on the inner wall of the shaft hole of the sealing element to absorb microwave energy leaking out along the gap between the metal wire and the sealing element.

7. The microwave additive manufacturing system according to claim 1, characterized in that, The control system includes a function generator that outputs pulse signals to synchronously control the wire feeding speed of the wire feeding system and the output power of the microwave system.

8. The microwave additive manufacturing system according to claim 1, characterized in that, The wire feeding system includes a wire feeding drive system and a wire feeding actuator; the wire feeding actuator is fixed on the mounting and support module and includes a wire guiding channel; the wire feeding drive system is used to receive phase timing control commands issued by the function generator to realize the wire feeding speed in the form of pulses.

9. A microwave additive manufacturing system according to any one of claims 1-8, characterized in that, The three-axis motion system includes: The X-axis lateral motion mechanism, the Y-axis forward and backward motion mechanism, and the Z-axis vertical lifting motion mechanism are used to realize the movement of the waveguide and the metal wire in the X-axis, Y-axis, and Z-axis directions, respectively. A linear guide mechanism for optical axes is used to guide motion; The three-axis motion control module is used to control the motion of the X-axis lateral motion mechanism, the Y-axis forward and backward motion mechanism, and the Z-axis vertical lifting motion mechanism.

10. A microwave additive manufacturing method, implemented using the microwave additive manufacturing system according to any one of claims 1-9, characterized in that, Includes the following steps: Step S1: Pass a metal wire through the microwave resonant cavity and the waveguide connected to the microwave resonant cavity, so that the end of the metal wire extends to the outlet of the waveguide. Step S2: Feed microwaves into the microwave resonant cavity, so that the microwaves are conducted through the waveguide to the end of the metal wire, inducing the end of the metal wire to discharge and melt; Step S3: Control the metal wire to be delivered to the outlet of the waveguide in a pulsed manner, and simultaneously control the molten metal wire to be deposited and formed according to a preset path.

Images